balancing cylinder

7/21/2019 Balancing Cylinder

1/33

Abstract:

A screw down cylinder, an upper backup roll chock, and an upper work roll chock are pressed against an upper crosshead by hydraulic cylinders, and an upper roll

cross mechanism is actuated, whereby the upper backup roll chock (upper backup roll), the upper work roll chock (upper work roll), and the screw down device(screw down cylinders) can be synchronously moved in the same direction via the upper crosshead.

Representative Image:

Inventors:

Yamamoto, ikio (!iroshima, "#)

$sugi, %oshihiro (!iroshima, "#)

%akemura, &ei'ou (!iroshima, "#)

&aya, Akira (!iroshima, "#)

Application umber:

*+-**

#ublication /ate:

*0+-1+-**0

2iling /ate:

*++-**-

34port 5itation:

5lick 6or automatic bibliography generation

Assignee:

itsubishi !eavy Industries, 7td. (%okyo, "#)#rimary 5lass:

-+-10

8ther 5lasses:

-+-9, -+-1

International 5lasses:

B21B1/22 B21B13/02 B21B13/14 B21B31/16 B21B31/18 B21B31/32B21B31/02B21B31/20 (I#5;): #atent Re6erences:

@01 Rolling stand with crossing back;up and+or working rolls 2ebruary, -**9 uambusch -+-9

@019 Rolling machine and rolling method ovember, -*** ihei et al.

2oreign Re6erences:

"#-**99*= April, -**

%B-1=09@ "une, 0

#rimary 34aminer:

7arson, 7owell A.

Attorney, Agent or 2irm:

tewart, &olasch C


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hori'ontal plane.

1. %he rolling mill o6 claim , wherein the rolling mill moves the roll chocks 6orward and rearward in a transport direction o6 a strip material, and the roll chockssupports the upper and lower rolling rolls, thereby causing central a4es o6 the rolls to cross each other, the rolling mill 6urther comprising: a roll cross unit adapted to

move the roll chocks to cross the upper and lower rolling rolls, the roll cross unit including the roll moving means and the screw down moving means.

0. %he rolling mill o6 claim 1, wherein the roll cross unit is a crosshead 6or supporting the roll chocks and the sc rew down unit, such that the roll chocks and the screw

down unit are movable in the transport di rection o6 the strip material.

@. %he rolling mill o6 claim 1, wherein the roll cross unit includes a mechanical moving mechanism provided on one o6 an entry side and a delivery side o6 the strip

material in the roll chocks, and a hydraulic moving mechanism provided on the other o6 the entry side and the delivery side.

. %he rolling mill o6 claim 1, wherein the rolling rolls include upper and lower work rolls rotatably supported by the housing vie work roll chocks and opposed to

each other, and upper and lover backup rolls rotatably supported by the housing via backup roll chocks and opposed to and contacted with the upper and lower work

rolls, and the roll cross unit moves the work roll chocks and the backup roll chocks by the crosshead.

=. %he rolling mill o6 claim , wherein, the rolling rolls includes upper and lower work rolls rotatably supported by the housing via work roll chocks and opposed to

each other, and upper and lower backup rolls rotatably supported by the housing via backup roll chocks and opposed to and contacted with the upper and lower work

rolls, the backup rolls opposed to and contacted with the work rolls are displaced in a transport direction o6 a strip material, and the roll moving unit and the screw

down moving unit are o66set move the roll chocks and the screw down unit in the transport direction o6 the strip material.

. %he rolling mill o6 claim , wherein the screw down moving unit inc ludes, a screw down cylinder that accommodates a screw down cylinder, and an actuator

supported by the housing 6or moving the screw down cylinder along the rotational a4es o6 the rolling rolls.

*. %he rolling mill o6 claim , wherein the screw down moving unit 6urther includes, a lever pivotally supported by the housing, a 6irst end o6 the lever being

connected to the actuator, and a second end o6 the lever being connected to the screw down cylinder.

. %he rolling mill o6 claim , wherein the screw down moving unit includes, a screw down cylinder that accommodates a screw down cylinder, and a 6irst actuator

supported by the housing, and a second actuator supported by the housing, the 6irst actuator and the second actuator act s imultaneously to move the screw down

cylinder along the rotational a4es o6 the rolling rolls.

-. %he rolling mill o6 claim , wherein the screw down moving unit 6urther includes, a 6 irst lever pivotally supported by the housing, a 6 irst end o6 the 6irst lever

being connected to the 6irst actuator, and a second end o6 the 6irst lever being connected to the screw down cylinder, and a second lever pivotally supported by the

housing, a 6irst end o6 the second lever being connected to the second actuator, and a second end o6 the second lever being connected to the screw down cylinder.

/escription:

%he entire disclosure o6 "apanese #atent Application o. -**;--=9 6iled on "ul. 9*, -** and "apanese #atent Application o. -**;9-@ 6iled on 8ct. *, -**

including speci6ication, claims, drawings and summary is incorporated herein by re6erence in its entirety.

BACKGROUND OF THE INVENTION

. 2ield o6 the Invention

%his invention relates to a rol ling mill and a rolling method 6or rolling a strip material or a bar material, which passes through upper and lower rolling rolls, to a

predetermined thickness.

-. /escription o6 Related Art

2ID. * schematically shows a conventional 6our high cross rolling mill.

In the conventional 6our high cross rolling mi ll, as shown in 2ID. *, upper and lower work roll chocks 002and 003are supported inside a housing 001. >ha6t portions

o6 upper and lower work rolls 004and 005are rotatably supported by the upper and lower work roll chocks 002and 003, respectively, and the upper work roll 004and

the lower work roll 005are disposed so as to be opposed to each other. $pper and lower backup roll chocks 006and 007are supported above and below the upper and

lower work roll chocks 002and 003. >ha6t portions o6 upper and lower backup rolls 008and 009are rotatably supported by the upper and lower backup roll chocks

006and 007, respectively. %he upper backup roll 008and the upper work roll 004are opposed to each other, while the lower backup roll 009and the lower work roll

005are opposed to each other. A screw down device 0106or imposing a rolling load on the upper work roll 004via the upper backup roll chock 006and the upperbackup roll 008is provided in an upper portion o6 the housing 001.

$pper crossheads 011and 0126or hori'ontally supporting the upper backup roll chock 006and the upper work roll chock 002are provided in the upper portion o6 the

housing 001and positioned on an entry side and a delivery side o6 the housing 001. %he upper crossheads 011, 012are hori'ontally movable by roll cross mechanisms

013, 014. 7ower crossheads 015and 0166or hori'ontally supporting the lower backup roll chock 007and the lower work roll chock 003are provided in a lower

portion o6 the housing 001and positioned on the entry side and the delivery side o6 the housing 001. %he lower crossheads 015, 016are hori'ontally movable by roll

cross mechanisms 017, 018.

%hus, when rolling is per6ormed, a strip > is 6ed 6rom the entry side o6 the housing 001, and passed between the upper work roll 004given a predetermined load by the

screw down device 010and the lower work roll 005, whereby the strip > is rolled. %he rolled strip > is delivered 6 rom the delivery side and supplied to a subseEuent

step.


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%he roll cross mechanisms 013, 014, 017, 018are actuated be6ore or during rolling, whereby the upper chocks 002, 006and the lower chocks 003, 007are moved in

directions di66erent 6rom each other via the crossheads 011, 012, 015, 016. As a result, the upper work roll 004and upper backup roll 008, and the lower work roll 005

and lower backup roll 009are turned in opposite directions about a roll center so that their rotation a4es will cross each other and the angle o6 their crossed a4es wi llbe set at a predetermined angle.


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shi6ting movement, the screw down means can constant ly apply a predetermined pressure to a sha6t center position o6 the rolling roll. As a result, a screw down 6orce

is properly imparted to the rolling roll, and stable rolling can be per6ormed.

%he rolling mill may be an o66set rolling mill in which the rolling rolls are composed o6 upper and lower work rolls rotatably supported in the housing via work roll

chocks and opposed to each other, and upper and lower backup rolls rotatably supported in the housing via backup roll chocks and opposed to and contacted with the

upper and lower work rolls the backup rolls opposed to and contacted with the work rolls are slightly displaced in a transport direction o6 a strip material and wherein

the roll moving means and the screw down moving means may be o66set cylinders 6or moving the roll chocks and the screw down means in the transport direction o6

the strip material. %hus, even when the rolling roll makes an o66set movement, the screw down means can constantly apply a predetermined pressure to a sha6t center

position o6 the rolling roll. As a result, a screw down 6orce is properly imparted to the rolling roll, and stable rolling can be per6ormed.

According to another aspect o6 the present invention, there is provided a rolling method which applies a predetermined pressure onto an upper rolling rol l by screw

down means provided in an upper portion o6 a housing, thereby rolling a strip material passing between the upper rolling roll and a lower rolling roll, 6urther

comprising moving the screw down means in synchronism with movement o6 the rolling roll when the rolling roll is moved in a hori'ontal plane during rolling o6 the

strip material.

According to this aspect, the screw down means can constantly apply a predetermined pressure to a predetermined position o6 the rolling roll. In this manner, a screw

down 6orce is properly imparted to the rolling roll, and stable rolling i s per6ormed. %hus, rolling accuracy can be increased, and a decrease in the li6e o6 the screw

down means can be prevented.

BRIEF DESCRIPTION OF THE DRAINGS

%he present invention will become more 6ully understood 6rom the detailed description given hereinbelow and the accompanying drawings which are given by way o6

illustration only, and thus are not limitative o6 the present invention, and wherein:

2ID. is a schematic view o6 a cross rolling mill as a rolling mill according to a 6irst embodiment o6 the present invention

2ID. - is a partial cutaway side view o6 the cross rolling mill o6 the 6irst embodiment

2ID. 9 is a sectional view taken along line IIIGIII o6 2ID. -

2ID. 1 is a partial cutaway 6ront view o6 the cross rolling mill

2ID. 0 is a partial cutaway 6ront view o6 a shi6t rolling mill as a rolling mill according to a second embodiment o6 the present invention

2ID. @ is a sectional view taken along line ?IG?I o6 2ID. 0

2ID. is a partial cutaway side view o6 a cross rolling mi ll as a rolling mill according to a third embodiment o6 the present invention

2ID. = is a sectional view taken along line ?IIIG?III o6 2ID.

2ID. is a detail drawing o6 a balance cylinder 6or a screw down device as a partial cutaway 6ront view o6 the cross rolling mill and

2ID. * is a schematic view o6 a conventional 6our high cross rolling mill.

DETAI!ED DESCRIPTION OF THE PRESENT INVENTION

#re6erred embodiments o6 the present invention will now be described in detail with re6erence to the accompanying drawings, which in no way limit the invention.

2irst 3mbodiment

A 6our high cross rolling mill as a rolling mill according to a 6irst embodiment is brie6ly described. As shown in 2ID. , upper and lower work roll chocks12

and13

are supported in a housing 11. >ha6t portions o6 upper and lower work rolls 14and 15are rotatably supported by the upper and lower work roll chocks 12and 13,

respectively, and the upper work roll 14and the lower work roll 15are opposed to each other. $pper and lower backup roll chocks 16and 17are supported above and

below the upper and lower work roll chocks 12and 13. >ha6t portions o6 upper and lower backup rolls 18and 19are rotatably supported by the upper and lower

backup roll chocks 16and 17, respectively. %he upper backup roll 18and the upper work roll 14are opposed to each other, while the lower backup roll 19and the

lower work roll 15are opposed to each other. A screw down device 206or imposing a rolling load on the upper work roll 14via the upper backup roll 18is provided in

an upper portion o6 the housing 11.

An upper crosshead 216or supporting the screw down device 20, upper work roll chock 12, and upper backup roll chock 16is provided in the upper portion o6 the

housing 11and positioned unilaterally on a delivery side o6 the housing 11. %he upper crosshead 21is hori'ontally movable by an upper roll cross mechanism 22.

!ydraulic cylinder mechanisms 23, 24, 256or pushing the screw down device 20, upper work roll chock 12, and upper backup roll chock 16are provided in the upper

portion o6 the housing 11and positioned unilaterally on an entry side o6 the housing 11. A lower crosshead 266or supporting the lower work roll chock 13and lower

backup roll chock 17is provided in a lower portion o6 the housing 11and positioned unilaterally on the delivery side o6 the housing 11. %he lower crosshead 26is


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28, 29press the lower backup roll chock 17b and lower work roll chock 13b against the housing 11via the lower crosshead 26along the transport direction o6 the strip

>. 5onseEuently, mill vibrations during rolling can be prevented.

In setting the crossing angle in the cross rolling mill o6 the present embodiment described above, the upper roll cross mechanism 22is actuated to move the upper

crosshead 21. %his movement results in the movement o6 the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a, which have been

pressed against the upper crosshead 21by the hydraulic cylinder mechanisms 23, 24, 25. %he lower roll cross mechanism 27is also actuated to move the lower

crosshead 26, thereby moving the lower backup roll chock 17b and lower work roll chock 13b which have been pressed against the lower crosshead 26by the

hydraulic cylinder mechanisms 28, 29. As a result, the upper work roll 14and upper backup roll 18, and the lower work roll 15and lower backup roll 19have their

a4es o6 rotation crossed, and the crossing angle can be set at a predetermined angle.

Bhen rolling is to be per6ormed at the set crossing angle, the screw down device 20is actuated 6or the strip > which is 6ed 6rom the entry side o6 the housing 11and

passed between the upper work roll 14and the lower work roll 15. As a result, the pressing 6orce o6 the screw down device 20is imposed, as a predetermined load, on

the strip > via the upper backup roll chocks 16a, 16b, upper backup roll 18and upper work roll 14to roll the strip > to a predetermined plate thickness.

In this case, the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a are synchronously moved by the upper roll cross mechanism 22

and hydraulic cylinder mechanisms 23, 24, 25via the upper crosshead 21at the time o6 setting the crossing angle. %hus, a positional set state in which the centers o6

the pistons 33a, 33b in the screw down cylinders 20a, 20b align with the sha6t center o6 the upper backup roll 18(upper work roll 14) is maintained. !ence, the screw

down cylinders 20a, 20bpress the proper positions o6 the upper backup roll chocks 16a, 16b, thus preventing the occurrence o6 a tipping moment in the upper backup

roll chocks 16a, 16b. 5onseEuently, a predetermined rolling load is properly imposed on the strip >, and stable rolling is per6ormed, whereby the strip > can be rolled

with high accuracy.

>ince no tipping moment occurs in the upper backup roll chocks 16a, 16b, one;side contact does not occur between the screw down cylinders 20a, 20b and the upper

backup roll chocks 16a, 16b, and the decrease in the li6e o6 the screw down device 20due to partial wear can be prevented.

3ven when the roll cross angle is to be changed during rolling o6 the strip >, the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a

are synchronously moved by the upper roll cross mechanism 22and hydraulic cylinder mechanisms 23, 24, 25via the upper crosshead 21. %hus, the screw downcylinders 20a, 20b constantly press the proper position o6 the upper backup roll chocks 16a, 16b in the same manner as described above, so that stable rolling o6 the

strip > can be carried out.

Bith the cross rolling mill o6 the present embodiment, as described above, the screw down device 20(screw down cylinders 20a, 20b) is synchronously moved in the

same direction, together with the upper chocks 12a, 16a (upper rolls 14, 18), via the upper crosshead 21by the actuation o6 the upper roll cross mechanism 22and the

thrusting o6 the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a against the upper crosshead 21by the hydraulic cylinder

mechanisms 23, 24, 25. %hus, the screw down device 20presses the proper position o6 the upper backup roll chock 16corresponding to the sha6t center o6 the upper

backup roll 18, with the positional relationship between the screw down device 20and the upper rolls 14, 18being retained. 5onseEuently, stable rolling takes place

constantly, so that the rolling accuracy o6 the strip > can be improved, and the decrease in the li6e o6 the screw down device 20due to partial wear can be prevented.

In the 6oregoing embodiment, the upper roll cross mechanism 22is composed o6 the cross drive motor 37, worm reduction gears 39, 40, etc. !owever, this structure is

not restrictive, and a cross drive motor and screw sha6ts may be used, or hydraulic cylinders may be used. %he hydraulic cylinder mechanisms 23, 24, 25may be other

mechanical moving mechanisms. oreover, the roll moving means and screw down moving means o6 the present invention are embodied by the upper roll cross

mechanism 22and hydraulic cylinder mechanisms 23, 24, 25. !owever, the roll moving means may be the upper roll cross mechanism 22and hydraulic cylinder

mechanisms 24, 25, while the screw down moving means may be other mechanical moving mechanisms or hydraulic moving mechanisms.

In the 6oregoing embodiment, moreover, the rolling mill o6 the present invention is described as a 6our high cross rolling mill o6 a unilateral cross type. !owever, the

invented rolling mill may be a cross rolling mill o6 a bilateral cross type having crossheads and roll cross mechanisms 6or right and le6t roll chocks. %he type o6 the

rolling mill is not limited to a cross rolling mill, and the invention is applicable to a shi6t rolling mill or an o66set rolling mill.

>econd 3mbodiment

A rolling mill according to a second embodiment is a shi6t rolling mill in which upper and lower work rolls can be sh i6ted in the roll a4is direct ion. In this shi6t rolling

mill, as shown in 2ID>. 0 and @, an upper work roll 53is rotatably supported by a housing 51(6rames 51a, 51b) via right and le6t upper work roll chocks 52a and 52b.

An upper backup roll 55is rotatably supported by the housing 51via right and le6t upper backup roll chocks 54a and 54b, and is opposed to and contacted with the

upper work roll 53. %he right and le6t upper backup roll chocks 54a and 54b are connected by connecting rods 56.

2urthermore, screw down cylinders 57a, 57b constituting a screw down device 57are provided in an upper portion o6 the housing 51and located above the upper

backup roll chocks 54a, 54b. In the screw down cylinders 57a, 57b, cylinder cases 58a, 58b are suspended and supported by suspending rods 59a, 59b at the upper

portion o6 the housing 51, and pistons 60a, 60b are supported so as to be movable upward and downward. 2lat bearings 61a, 61b are interposed between the housing

51and the cylinder cases 58a, 58b, and the cylinder cases 58a and 58b are connected together by connecting members 62. 7ower sur6aces o6 the pistons 60a, 60b are

in contact with upper sur6ace portions o6 the right and le6t upper backup roll chocks 54a and 54b. %he positions o6 these members are set such that the screw down

cylinders57

a and57

b are provided symmetrically in the a4ial direct ion with respect to the upper backup roll55

(upper work roll53

), and press the upper backup roll55(upper work roll 53) in a laterally balanced manner via the upper backup roll chocks 54a, 54b.

%he screw down cylinders 57a, 57b, upper backup roll chocks 54a, 54b (upper backup roll 55), and upper work roll chocks 52a, 52b (upper work roll 53) are movable

in the roll a4is direction by upper shi6t cylinders 63(screw down moving means) and 64, 65(roll moving means). %he shi6t cylinders 63, 64, 65will be described

below, but since they have practically the same con6iguration, an e4planation is o66ered 6or the shi6t cylinder 63alone.

A pair o6 hydraulic cylinders 72a and 72b constituting the upper shi6t cylinder 63and symmetrical to each other are mounted on the entry side and the delivery side o6

the 6rame 51b o6 the housing 51by mounting brackets 71a and 71b. 3nd portions o6 pivotable operating levers 73a and 73b are connected to the hydraulic cylinders

72a and 72b. 5onnecting 6langes 74a, 74b are attached to the cylinder case 58b o6 the screw down cylinder 57b, and end portions o6 the connecting 6langes 74a, 74bare in engagement with other end portions o6 the operating levers 73a, 73b. %hus, when the hydraulic cylinders 72a, 72b are synchronously actuated to pivot the

operating levers 73a, 73b in the opposite direction, the screw down cylinders 57a, 57b can be moved in the roll a4is di rection via the connecting 6langes 74a, 74b.


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In the shi6t rolling mill, only the upper work roll 53, upper backup roll 55and screw down device 57provided in the upper portion o6 the housing 51have been

described. A lower work roll 75, and a lower backup roll (not shown) are provided so as to be opposed to the upper work roll 53and upper backup roll 55. %he lower

work roll 75and lower backup roll are movable in the roll a4is direction by lower shi6t cylinders (not shown) provided on the 6rame 51a.

Bhen shi6t positions o6 the upper and lower work rolls 53and 75are to be set by the above;described shi6t rolling mill o6 the present embodiment, the upper shi6t

cylinders 63, 64, 65are synchronously actuated to move the screw down cylinders 57a, 57b, upper backup roll chocks 54a, 54b and upper work roll chocks 52a, 52b

in one roll a4is direction. Bhereas the lower shi6t cylinders are synchronously actuated to move the lower backup roll chocks and lower work roll chocks in the other

roll a4is direction. , there6ore, a predetermined rolling load acts properly on the strip >, ensuring stable rolling. !ence, the

strip > can be rolled with high accuracy.

In the above;described embodiment, the upper shi6t cylinder 63is provided as the screw down moving means o6 the present invention, and the upper shi6t cylinders

64, 65are provided as the roll moving means. !owever, one shi6t cylinder may be adapted to move the screw down cylinders 57a, 57b, upper backup roll chocks 54a,

54b and upper work roll chocks 52a, 52b synchronously in the roll a4is direction.

Bhen the rolling mill o6 the present invention is applied to an o66set rolling mill, the roll moving means and screw down moving means may be o66set cylinders 6or

moving the roll chocks and screw down device in the transport direction o6 the strip.

%hird 3mbodiment

In a 6our high cross rolling mi ll according to a third embodiment, 6irst balance cylinders provided at an intermediate portion o6 a housing 11push up upper backup roll

chocks 16a, 16b and an upper backup roll 18to bear their weights. Bhereas second balance cylinders provided at an upper portion o6 the housing 11suspend screwdown cylinders 20a, 20b, which constitute a screw down device 20, to bear their weights.

%hat is, as shown in 2ID>. and =, mounting brackets 81a, 81b are attached to upper portions o6 6rames 11a, 11b o6 the housing 11. >econd balance cylinders 82a,82b are suspended 6rom and connected to the mounting brackets 81a, 81b via spherical bushes 83a, 83b. 5onnecting rods 86a, 86b are connected to drive rods 84a,

84b o6 the second balance cylinders 82a, 82b via spherical bushes 85a, 85b, and the connecting rods 86a, 86b are attached to cylinder cases 31a, 31b. /uring rolling

o6 a strip >, the second balance cylinders 82a, 82bpull up the screw down cylinders 20a, 20b to bear the weights o6 the screw down cylinders 20a, 20b, thereby

canceling out these weights so as not to a66ect the rolling accuracy o6 the strip >.

A 6lat bearing 34a and a conical roller bearing 34b are interposed between the 6rames 11a, 11b and the cylinder cases 31a, 31b, and the cylinder cases 31a and 31b are

connected together by connecting rods 35. 7ower sur6aces o6 pistons 33a and 33b are in contact with upper sur6ace portions o6 right and le6t upper backup roll chocks16a and 16b.

2irst balance cylinders 43(see 2ID. -) are mounted on intermediate portions o6 the 6rames 11a and 11b to enable the right and le6t upper backup roll chocks 16a and

16b to be pushed up. /uring rolling o6 the strip >, the balance cylinders 43push up the upper backup roll chocks 16a and 16b to bear the weights o6 the upper backup

roll chocks 16a, 16b and upper backup roll 18, thereby canceling out the weights o6 the respective devices so as not to a66ect the rolling accuracy o6 the strip >.

%he 6our high cross rolling mi ll o6 the present embodiment is also eEuipped with the same roll cross mechanisms 22, 27and hydraulic cylinder mechanisms 23, 24, 25,

28, 29as in the a6orementioned 6irst embodiment, although these mechanisms are not shown. >ince their structures and actions are practically the same, their duplicate

e4planations are omitted.

In setting the crossing angle in the cross rolling mill o6 the present embodiment described above, the upper roll cross mechanism 22and hydraulic cylinder

mechanisms 23, 24, 25are actuated, and the lower roll cross mechanism 27and hydraulic cylinder mechanisms 28, 29are also actuated. As a result, the upper work

roll 14and upper backup roll 18, and the lower work roll 15and lower backup roll 19have their a4es o6 rotation crossed, and the crossing angle can be set at a

predetermined angle.

At this time, the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a are synchronously moved by the upper roll cross mechanism

22and hydraulic cylinder mechanisms 23, 24, 25via the upper crosshead 21. %hus, a positional set state in which the centers o6 the pistons 33a, 33b in the screw

down cylinders 20a, 20b align with the sha6t center o6 the upper backup roll 18(upper work roll 14) is maintained. !ence, the screw down cylinders 20a, 20bpress

the proper positions o6 the upper backup roll chocks 16a, 16b, thus preventing the occurrence o6 a tipping moment in the upper backup roll chocks 16a, 16b. Also, a

predetermined rolling load is properly imposed on the strip >, and stable rolling is per6ormed, whereby the strip > can be rolled with high accuracy.

Bhen the roll cross angle is set, the screw down cylinders 20a, 20b move together with the upper backup roll chocks 16a, 16b and upper work roll chocks 12a, 12b.

%he screw down cylinders 20a, 20b are suspended 6rom and supported by the 6rames 11a, 11b via the second balance cylinders 82a, 82b and spherical bushes 83a,83b, 85a, 85b. %hus, the amounts o6 hori'ontal movements o6 the screw down cylinders 20a, 20b relative to the 6rames 11a, 11b are absorbed by the spherical bushes

83a, 83b, 85a, 85b.

Bith the cross rolling mill o6 the present embodiment, as described above, the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a

are synchronously moved in the same direction when the crossing angle is set. %hus, the screw down device 20presses the proper position, without destroying its

positional relationship with the upper rolls 14, 18. 5onseEuently, stable rolling takes place constantly, so that the rolling accuracy o6 the strip > can be improved, and

the decrease in the li6e o6 the screw down device 20due to partial wear can be prevented.

At this time, the amounts o6 hori'ontal movements o6 the screw down cylinders 20a, 20b relative to the 6rames 11a, 11b are absorbed by the spherical bushes 83a, 83b,

85a, 85b. %hus, the property o6 the screw down cylinder 20a 6ollowing the upper backup roll chock 16a and the upper work roll chock 12a can be improved. Bhen the


8/33

strip > is rolled, the second balance cylinders 82a, 82b work, li6ting the screw down device 20(screw down cylinders 20a, 20b) and bearing its weight. !ence, the

weight o6 the screw down device 20does not adversely a66ect the rolling accuracy o6 the strip >.

Bhile the present invention has been described in the 6oregoing 6ashion, it is to be understood that the invention is not limited thereby, but may be varied in many

other ways. >uch variations are not to be regarded as a departure 6rom the spirit and scope o6 the invention, and all such modi6ications as would be obvious to one

skilled in the art are intended to be included within the scope o6 the appended claims.

Abstract:

A screw down cylinder, an upper backup roll chock, and an upper work roll chock are pressed against an upper crosshead by hydraulic cylinders, and an upper rollcross mechanism is actuated, whereby the upper backup roll chock (upper backup roll), the upper work roll chock (upper work roll), and the screw down device

(screw down cylinders) can be synchronously moved in the same direction via the upper crosshead.

Representative Image:

Inventors:

Yamamoto, ikio (!iroshima, "#)

$sugi, %oshihiro (!iroshima, "#)

%akemura, &ei'ou (!iroshima, "#)

&aya, Akira (!iroshima, "#)

Application umber:

*+-**

#ublication /ate:

*0+-1+-**0

2iling /ate:

*++-**-

34port 5itation:

5lick 6or automatic bibliography generation

Assignee:

itsubishi !eavy Industries, 7td. (%okyo, "#)

#rimary 5lass:

-+-10

8ther 5lasses:

-+-9, -+-1

International 5lasses:

B21B1/22 B21B13/02 B21B13/14 B21B31/16 B21B31/18 B21B31/32B21B31/02B21B31/20 (I#5;): #atent Re6erences:

@01 Rolling stand with crossing back;up and+or working rolls 2ebruary, -**9 uambusch -+-9

@019 Rolling machine and rolling method ovember, -*** ihei et al.2oreign Re6erences:

"#-**99*= April, -**

%B-1=09@ "une, 0

#rimary 34aminer:

7arson, 7owell A.

Attorney, Agent or 2irm:

tewart, &olasch C


9/33

that the rolling rolls move in the hori'ontal planes and a screw down moving unit adapted to move the screw down unit in a hori'ontal plane, wherein the roll moving

unit and the screw down moving unit are actuated simultaneously, such that the roll chocks and the screw down unit move simultaneously along rotational a4es o6 the

rolling rolls.

-. %he rolling mill o6 claim , wherein the roll moving unit and the screw down moving unit act as a single synchronous moving unit, and the roll chocks and the

screw down unit are adapted to be synchronously moved by the synchronous moving unit.

9. %he rolling mill o6 claim , wherein the screw down unit includes hydraulic cylinders, supported by the upper portion o6 the housing so as to be movable in the

hori'ontal plane.

1. %he rolling mill o6 claim , wherein the rolling mill moves the roll chocks 6orward and rearward in a transport direction o6 a strip material, and the roll chocks

supports the upper and lower rolling rolls, thereby causing central a4es o6 the rolls to cross each other, the rolling mill 6urther comprising: a roll cross unit adapted to

move the roll chocks to cross the upper and lower rolling rolls, the roll cross unit including the roll moving means and the screw down moving means.

0. %he rolling mill o6 claim 1, wherein the roll cross unit is a crosshead 6or supporting the roll chocks and the sc rew down unit, such that the roll chocks and the screw

down unit are movable in the transport di rection o6 the strip material.

@. %he rolling mill o6 claim 1, wherein the roll cross unit includes a mechanical moving mechanism provided on one o6 an entry side and a delivery side o6 the strip

material in the roll chocks, and a hydraulic moving mechanism provided on the other o6 the entry side and the delivery side.

. %he rolling mill o6 claim 1, wherein the rolling rolls include upper and lower work rolls rotatably supported by the housing vie work roll chocks and opposed to

each other, and upper and lover backup rolls rotatably supported by the housing via backup roll chocks and opposed to and contacted with the upper and lower work

rolls, and the roll cross unit moves the work roll chocks and the backup roll chocks by the crosshead.

=. %he rolling mill o6 claim , wherein, the rolling rolls includes upper and lower work rolls rotatably supported by the housing via work roll chocks and opposed to

each other, and upper and lower backup rolls rotatably supported by the housing via backup roll chocks and opposed to and contacted with the upper and lower work

rolls, the backup rolls opposed to and contacted with the work rolls are displaced in a transport direction o6 a strip material, and the roll moving unit and the screw

down moving unit are o66set move the roll chocks and the screw down unit in the transport direction o6 the strip material.

. %he rolling mill o6 claim , wherein the screw down moving unit inc ludes, a screw down cylinder that accommodates a screw down cylinder, and an actuator

supported by the housing 6or moving the screw down cylinder along the rotational a4es o6 the rolling rolls.

*. %he rolling mill o6 claim , wherein the screw down moving unit 6urther includes, a lever pivotally supported by the housing, a 6irst end o6 the lever being

connected to the actuator, and a second end o6 the lever being connected to the screw down cylinder.

. %he rolling mill o6 claim , wherein the screw down moving unit includes, a screw down cylinder that accommodates a screw down cylinder, and a 6irst actuator

supported by the housing, and a second actuator supported by the housing, the 6irst actuator and the second actuator act s imultaneously to move the screw downcylinder along the rotational a4es o6 the rolling rolls.

-. %he rolling mill o6 claim , wherein the screw down moving unit 6urther includes, a 6 irst lever pivotally supported by the housing, a 6 irst end o6 the 6irst lever

being connected to the 6irst actuator, and a second end o6 the 6irst lever being connected to the screw down cylinder, and a second lever pivotally supported by the

housing, a 6irst end o6 the second lever being connected to the second actuator, and a second end o6 the second lever being connected to the screw down cylinder.

/escription:

%he entire disclosure o6 "apanese #atent Application o. -**;--=9 6iled on "ul. 9*, -** and "apanese #atent Application o. -**;9-@ 6iled on 8ct. *, -**including speci6ication, claims, drawings and summary is incorporated herein by re6erence in its entirety.

BACKGROUND OF THE INVENTION

. 2ield o6 the Invention

%his invention relates to a rol ling mill and a rolling method 6or rolling a strip material or a bar material, which passes through upper and lower rolling rolls, to a

predetermined thickness.

-. /escription o6 Related Art

2ID. * schematically shows a conventional 6our high cross rolling mill.

In the conventional 6our high cross rolling mi ll, as shown in 2ID. *, upper and lower work roll chocks 002and 003are supported inside a housing 001. >ha6t portions

o6 upper and lower work rolls 004and 005are rotatably supported by the upper and lower work roll chocks 002and 003, respectively, and the upper work roll 004and

the lower work roll 005are disposed so as to be opposed to each other. $pper and lower backup roll chocks 006and 007are supported above and below the upper and

lower work roll chocks 002and 003. >ha6t portions o6 upper and lower backup rolls 008and 009are rotatably supported by the upper and lower backup roll chocks

006and 007, respectively. %he upper backup roll 008and the upper work roll 004are opposed to each other, while the lower backup roll 009and the lower work roll

005are opposed to each other. A screw down device 0106or imposing a rolling load on the upper work roll 004via the upper backup roll chock 006and the upper

backup roll 008is provided in an upper portion o6 the housing 001.

$pper crossheads 011and 0126or hori'ontally supporting the upper backup roll chock 006and the upper work roll chock 002are provided in the upper portion o6 the

housing 001and positioned on an entry side and a delivery side o6 the housing 001. %he upper crossheads 011, 012are hori'ontally movable by roll cross mechanisms

013, 014. 7ower crossheads 015and 0166or hori'ontally supporting the lower backup roll chock 007and the lower work roll chock 003are provided in a lower


10/33

portion o6 the housing 001and positioned on the entry side and the delivery side o6 the housing 001. %he lower crossheads 015, 016are hori'ontally movable by roll

cross mechanisms 017, 018.

%hus, when rolling is per6ormed, a strip > is 6ed 6rom the entry side o6 the housing 001, and passed between the upper work roll 004given a predetermined load by the

screw down device 010and the lower work roll 005, whereby the strip > is rolled. %he rolled strip > is delivered 6 rom the delivery side and supplied to a subseEuent

step.

%he roll cross mechanisms 013, 014, 017, 018are actuated be6ore or during rolling, whereby the upper chocks 002, 006and the lower chocks 003, 007are moved in

directions di66erent 6rom each other via the crossheads 011, 012, 015, 016. As a result, the upper work roll 004and upper backup roll 008, and the lower work roll 005and lower backup roll 009are turned in opposite directions about a roll center so that their rotation a4es will cross each other and the angle o6 their crossed a4es wi ll

be set at a predetermined angle.


11/33

In the rolling mill, the rol ling rolls may include upper and lower work rolls rotatably supported in the housing via work roll chocks and opposed to each other, and

upper and lower backup rolls rotatably supported in the housing via backup roll chocks and opposed to and contacted with the upper and lower work rolls, and the roll

cross means may move the work roll chocks and the backup roll chocks by the crosshead. %hus, the roll cross means moves the screw down means, work roll chocksand backup roll chocks via the crosshead, so that the accuracy o6 the position, to which the members are moved, can be increased.

%he rolling mill may be a shi6t rolling mill 6or shi6ting the upper and lower rolling rolls in a roll a4is direction, and wherein the roll moving means and the screw down

moving means may be a shi6t cylinder 6or moving the roll chocks and the screw down means in the roll a4is direction. %hus, even when the rolling roll makes a

shi6ting movement, the screw down means can constant ly apply a predetermined pressure to a sha6t center position o6 the rolling roll. As a result, a screw down 6orce

is properly imparted to the rolling roll, and stable rolling can be per6ormed.

%he rolling mill may be an o66set rolling mill in which the rolling rolls are composed o6 upper and lower work rolls rotatably supported in the housing via work roll

chocks and opposed to each other, and upper and lower backup rolls rotatably supported in the housing via backup roll chocks and opposed to and contacted with the

upper and lower work rolls the backup rolls opposed to and contacted with the work rolls are slightly displaced in a transport direction o6 a strip material and wherein

the roll moving means and the screw down moving means may be o66set cylinders 6or moving the roll chocks and the screw down means in the transport direction o6

the strip material. %hus, even when the rolling roll makes an o66set movement, the screw down means can constantly apply a predetermined pressure to a sha6t center

position o6 the rolling roll. As a result, a screw down 6orce is properly imparted to the rolling roll, and stable rolling can be per6ormed.

According to another aspect o6 the present invention, there is provided a rolling method which applies a predetermined pressure onto an upper rolling rol l by screw

down means provided in an upper portion o6 a housing, thereby rolling a strip material passing between the upper rolling roll and a lower rolling roll, 6urther

comprising moving the screw down means in synchronism with movement o6 the rolling roll when the rolling roll is moved in a hori'ontal plane during rolling o6 the

strip material.

According to this aspect, the screw down means can constantly apply a predetermined pressure to a predetermined position o6 the rolling roll. In this manner, a screw

down 6orce is properly imparted to the rolling roll, and stable rolling i s per6ormed. %hus, rolling accuracy can be increased, and a decrease in the li6e o6 the screw

down means can be prevented.

BRIEF DESCRIPTION OF THE DRAINGS

%he present invention will become more 6ully understood 6rom the detailed description given hereinbelow and the accompanying drawings which are given by way o6

illustration only, and thus are not limitative o6 the present invention, and wherein:

2ID. is a schematic view o6 a cross rolling mill as a rolling mill according to a 6irst embodiment o6 the present invention

2ID. - is a partial cutaway side view o6 the cross rolling mill o6 the 6irst embodiment

2ID. 9 is a sectional view taken along line IIIGIII o6 2ID. -

2ID. 1 is a partial cutaway 6ront view o6 the cross rolling mill

2ID. 0 is a partial cutaway 6ront view o6 a shi6t rolling mill as a rolling mill according to a second embodiment o6 the present invention

2ID. @ is a sectional view taken along line ?IG?I o6 2ID. 0

2ID. is a partial cutaway side view o6 a cross rolling mi ll as a rolling mill according to a third embodiment o6 the present invention

2ID. = is a sectional view taken along line ?IIIG?III o6 2ID.

2ID. is a detail drawing o6 a balance cylinder 6or a screw down device as a partial cutaway 6ront view o6 the cross rolling mill and

2ID. * is a schematic view o6 a conventional 6our high cross rolling mill.

DETAI!ED DESCRIPTION OF THE PRESENT INVENTION

#re6erred embodiments o6 the present invention will now be described in detail with re6erence to the accompanying drawings, which in no way limit the invention.

2irst 3mbodiment

A 6our high cross rolling mill as a rolling mill according to a 6irst embodiment is brie6ly described. As shown in 2ID. , upper and lower work roll chocks 12and 13

are supported in a housing 11. >ha6t portions o6 upper and lower work rolls 14and 15are rotatably supported by the upper and lower work roll chocks 12and 13,

respectively, and the upper work roll 14and the lower work roll 15are opposed to each other. $pper and lower backup roll chocks 16and 17are supported above and

below the upper and lower work roll chocks 12and 13. >ha6t portions o6 upper and lower backup rolls 18and 19are rotatably supported by the upper and lower

backup roll chocks 16and 17, respectively. %he upper backup roll 18and the upper work roll 14are opposed to each other, while the lower backup roll 19and the


12/33

lower work roll 15are opposed to each other. A screw down device 206or imposing a rolling load on the upper work roll 14via the upper backup roll 18is provided in

an upper portion o6 the housing 11.

An upper crosshead 216or supporting the screw down device 20, upper work roll chock 12, and upper backup roll chock 16is provided in the upper portion o6 the

housing 11and positioned unilaterally on a delivery side o6 the housing 11. %he upper crosshead 21is hori'ontally movable by an upper roll cross mechanism 22.

!ydraulic cylinder mechanisms 23, 24, 256or pushing the screw down device 20, upper work roll chock 12, and upper backup roll chock 16are provided in the upper

portion o6 the housing 11and positioned unilaterally on an entry side o6 the housing 11. A lower crosshead 266or supporting the lower work roll chock 13and lower

backup roll chock 17is provided in a lower portion o6 the housing 11and positioned unilaterally on the delivery side o6 the housing 11. %he lower crosshead 26is

hori'ontally movable by a lower roll cross mechanism 27. !ydraulic cylinder mechanisms 28, 296or pushing the lower work rol l chock 13and lower backup roll

chock 17are provided in the lower portion o6 the housing 11and positioned unilaterally on the entry side o6 the housing 11.

%hus, when a strip > is 6ed 6rom the entry side o6 the housing 11and a predetermined load is imposed by the screw down device 20, the strip > is subFected to a rolling

load when it passes between the upper work roll 14and the lower work roll 15, whereby it is rolled to a predetermined plate thickness. At this time, the hydraulic

cylinder mechanisms 23, 24, 25, 28, 29and the roll cross mechanisms 22, 27are actuated to move the upper chocks 12, 16and the lower chocks 13, 17in di66erent

directions via the cross heads 21, 26. As a result, the upper work roll 14and upper backup roll 18and the lower work roll 15and lower backup roll 19have their

rotation a4es crossed, and the angle o6 their crossed a4es is set at a predetermined angle to control the strip crown.

According to the present embodiment, when the crossing angle between the upper work roll 14and upper backup roll 18and the lower work roll 15and lower backup

roll 19is set by the roll cross mechanisms 22, 27, the screw down device 20is synchronously moved in the same direction together with the upper chocks 12, 16

(upper work roll 14and upper backup roll 18). . - to 4, the housing 11comprises right and le6t

6rames 11a and 11b as a pair. Right and le6t upper work roll chocks 12a and 12b are supported at upper portions o6 the 6rames 11a and 11b, while right and le6t lower

work roll chocks 13a and 13b are supported at lower portions o6 the 6rames 11a and 11b. >ha6t portions o6 upper and lower work rolls 14and 15are rotatably

supported by the upper and lower work roll chocks 12a, 12b, 13a and 13b.

Right and le6t upper backup roll chocks 16a and 16b are supported at the upper portions o6 the 6rames 11a and 11b o6 the housing 11, and located above the upper

work roll chocks 12a and 12b. Right and le6t lower backup roll chocks 17a and 17b are supported at the lower portions o6 the 6rames 11a and 11b o6 the housing 11,

and located below the lower work roll chocks 13a and 13b. >ha6t portions o6 upper and lower backup rolls 18and 19are rotatably supported by the upper and lower

backup roll chocks 16a, 16b, 17a and 17b.

2urthermore, right and le6t screw down cylinders 20a and 20b constituting the screw down device 20are provided in the upper portions o6 the 6rames 11a and 11b o6

the housing 11and located above the upper backup roll chocks 16a and 16b. In the screw down cylinders 20a and 20b, cylinder cases 31a and 31b are suspended and

supported by suspending rods 32a and 32b at the upper portions o6 the 6rames 11a and 11b. #istons 33a and 33b are supported within the cylinder cases 31a and 31b

so as to be movable upward and downward. %hus, even when the upper backup roll chocks 16a and 16b are withdrawn a4ially together with the upper work roll

chocks 12a and 12b during roll changing, the screw down cylinders 20a and 20b do not become detached.

A 6lat bearing 34a and a conical roller bearing 34a are interposed between the 6rames 11a, 11b and the cylinder cases 31a, 31b, and the cylinder cases 31a and 31b are

connected together by connecting rods 35. 7ower sur6aces o6 the pistons 33a and 33b are in contact with upper sur6ace portions o6 the right and le6t upper backup roll

chocks 16a and 16b. %he positions o6 the members are set such that the centers o6 the pistons 33a and 33b in the screw down cylinders 20a and 20bpress proper

positions o6 the upper backup roll chocks 16a and 16b corresponding to the sha6t center o6 the upper backup roll 18.

, the balance cylinders 43push up the upper backup roll chocks 16a and 16b to bear the weights o6 the upper backup roll chocks 16a,

16b, upper backup roll 18, and screw down cylinders 20a, 20b, thereby canceling out the weights o6 the respective devices so as not to a66ect the rolling accuracy o6

the strip >.

%he upper crosshead 21is located in the upper portion o6 the 6rame 11a o6 the housing 11and provided on the delivery side o6 the housing 11. %he hydraulic cylinder

mechanisms 23, 24, 25are located in the upper portion o6 the 6rame 11a o6 the housing 11and provided on the entry side o6 the housing 11. In this case, the cylinder

case 31b, upper backup roll chock 16b, and upper work roll chock 12b on the drive side are supported by spherical bearings 36so as to be pivotable about a vertical

a4is relative to the 6rame 11b. %he cylinder case 31a, upper backup roll chock 16a, and upper work roll chock 12a on the work side are pushed toward the upper

crosshead 21by the hydraulic cylinder mechanisms 23, 24, 25, and are supported so as to be movable along the transport direction o6 the strip >, integrally with the

6rame 11a, by the upper roll cross mechanism 22via the upper crosshead 21.

In the upper roll cross mechanism 22, a cross drive motor 37is attached to the upper portion o6 the 6rame 11a o6 the housing 11, and a drive rod 38is connected to an

output sha6t o6 the cross drive motor 37. $pper and lower worm reduction gears 39and 40are mounted on a side portion o6 the 6rame 11a, and a lower end portion o6

the drive rod 38is drivingly connected to the worm reduction gears 39and 40. 2ront end portions o6 driven rods 41and 42having base end portions drivably

connected to the warm reduction gears 39and 40are connected to the upper crosshead 21. %hus, the cylinder case 31a, upper backup roll chock 16a and upper work

roll chock 12a are pressed against the upper crosshead 21by the hydraulic cylinder mechanisms 23, 24, 25. Also, the upper crosshead 21is moved along the transportdirection o6 the strip > by the driving o6 the cross drive motor 37via the drive rod 38, worm reduction gears 39, 40and driven rods 41, 42. In this manner, the cylinder

case 31a, upper backup roll chock 16a and upper work roll chock 12a can be moved in synchronism.

%he hydraulic cylinder mechanisms 23, 24, 25also press the cylinder case 31a, upper backup roll chock 16a and upper work roll chock 12a against the housing 11viathe upper crosshead 21along the transport direction o6 the strip >. 5onseEuently, the inward narrowing de6ormation amount H o6 the housing 11in response to the

screw down load is decreased, and the hori'ontal dynamic sti66ness o6 the rolling mill is kept high. %hus, mill vibrations during rolling can be prevented. %he cylinder

cases 31a, 31b are provided with detection sensors 44a, 44b which detect the amounts o6 movement o6 the screw down cylinders 20a, 20b when the crossing angle is

set by the upper roll cross mechanism 22and hydraulic cylinder mechanisms 23, 24, 25.

%he lower crosshead 26is located in the lower portion o6 the 6rame 11b o6 the housing 11and provided on the delivery side o6 the housing 11. %he hydraulic cylinder

mechanisms 28, 29are located in the lower portion o6 the 6rame 11b o6 the housing 11and provided on the entry side o6 the housing 11. In this case, the lower backup


13/33

roll chock 17a, and lower work roll chock 13a on the work side are supported by spherical bearings (not shown) so as to be pivotable about a vertical a4is relative to

the 6rame 11a. %he lower backup roll chock 17b and lower work roll chock 13b on the drive side are thrust against the lower crosshead 26by the hydraulic cylinder

mechanisms 28, 29, and are supported so as to be movable along the transport direction o6 the strip >, integrally with the 6rame 11b, by the lower roll cross mechanism27via the lower crosshead 26.

%he lower roll cross mechanism 27has practically the same con6iguration as that o6 the a6orementioned upper roll cross mechanism 22(its e4planation is omitted).

%hus, the lower crosshead 26is moved along the transport direction o6 the strip > by the action o6 the lower roll cross mechanism 27and hydraulic cylinder

mechanisms 28, 29, and the lower backup roll chock 17b and lower work roll chock 13b can be moved in synchronism. oreover, the hydraulic cylinder mechanisms

28, 29press the lower backup roll chock 17b and lower work roll chock 13b against the housing 11via the lower crosshead 26along the transport direction o6 the strip

>. 5onseEuently, mill vibrations during rolling can be prevented.

In setting the crossing angle in the cross rolling mill o6 the present embodiment described above, the upper roll cross mechanism 22is actuated to move the upper

crosshead 21. %his movement results in the movement o6 the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a, which have been

pressed against the upper crosshead 21by the hydraulic cylinder mechanisms 23, 24, 25. %he lower roll cross mechanism 27is also actuated to move the lower

crosshead 26, thereby moving the lower backup roll chock 17b and lower work roll chock 13b which have been pressed against the lower crosshead 26by the

hydraulic cylinder mechanisms 28, 29. As a result, the upper work roll 14and upper backup roll 18, and the lower work roll 15and lower backup roll 19have their

a4es o6 rotation crossed, and the crossing angle can be set at a predetermined angle.

Bhen rolling is to be per6ormed at the set crossing angle, the screw down device 20is actuated 6or the strip > which is 6ed 6rom the entry side o6 the housing 11and

passed between the upper work roll 14and the lower work roll 15. As a result, the pressing 6orce o6 the screw down device 20is imposed, as a predetermined load, on

the strip > via the upper backup roll chocks 16a, 16b, upper backup roll 18and upper work roll 14to roll the strip > to a predetermined plate thickness.

In this case, the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a are synchronously moved by the upper roll cross mechanism 22

and hydraulic cylinder mechanisms 23, 24, 25via the upper crosshead 21at the time o6 setting the crossing angle. %hus, a positional set state in which the centers o6

the pistons 33a, 33b in the screw down cylinders 20a, 20b align with the sha6t center o6 the upper backup roll 18(upper work roll 14) is maintained. !ence, the screw

down cylinders 20a, 20bpress the proper positions o6 the upper backup roll chocks 16a, 16b, thus preventing the occurrence o6 a tipping moment in the upper backup

roll chocks 16a, 16b. 5onseEuently, a predetermined rolling load is properly imposed on the strip >, and stable rolling is per6ormed, whereby the strip > can be rolled

with high accuracy.

>ince no tipping moment occurs in the upper backup roll chocks 16a, 16b, one;side contact does not occur between the screw down cylinders 20a, 20b and the upper

backup roll chocks 16a, 16b, and the decrease in the li6e o6 the screw down device 20due to partial wear can be prevented.

3ven when the roll cross angle is to be changed during rolling o6 the strip >, the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a

are synchronously moved by the upper roll cross mechanism 22and hydraulic cylinder mechanisms 23, 24, 25via the upper crosshead 21. %hus, the screw down

cylinders 20a, 20b constantly press the proper position o6 the upper backup roll chocks 16a, 16b in the same manner as described above, so that stable rolling o6 the

strip > can be carried out.

Bith the cross rolling mill o6 the present embodiment, as described above, the screw down device 20(screw down cylinders 20a, 20b) is synchronously moved in the

same direction, together with the upper chocks 12a, 16a (upper rolls 14, 18), via the upper crosshead 21by the actuation o6 the upper roll cross mechanism 22and the

thrusting o6 the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a against the upper crosshead 21by the hydraulic cylinder

mechanisms 23, 24, 25. %hus, the screw down device 20presses the proper position o6 the upper backup roll chock 16corresponding to the sha6t center o6 the upper

backup roll 18, with the positional relationship between the screw down device 20and the upper rolls 14, 18being retained. 5onseEuently, stable rolling takes place

constantly, so that the rolling accuracy o6 the strip > can be improved, and the decrease in the li6e o6 the screw down device20

due to partial wear can be prevented.

In the 6oregoing embodiment, the upper roll cross mechanism 22is composed o6 the cross drive motor 37, worm reduction gears 39, 40, etc. !owever, this structure is

not restrictive, and a cross drive motor and screw sha6ts may be used, or hydraulic cylinders may be used. %he hydraulic cylinder mechanisms 23, 24, 25may be other

mechanical moving mechanisms. oreover, the roll moving means and screw down moving means o6 the present invention are embodied by the upper roll crossmechanism 22and hydraulic cylinder mechanisms 23, 24, 25. !owever, the roll moving means may be the upper roll cross mechanism 22and hydraulic cylinder

mechanisms 24, 25, while the screw down moving means may be other mechanical moving mechanisms or hydraulic moving mechanisms.

In the 6oregoing embodiment, moreover, the rolling mill o6 the present invention is described as a 6our high cross rolling mill o6 a unilateral cross type. !owever, the

invented rolling mill may be a cross rolling mill o6 a bilateral cross type having crossheads and roll cross mechanisms 6or right and le6t roll chocks. %he type o6 the

rolling mill is not limited to a cross rolling mill, and the invention is applicable to a shi6t rolling mill or an o66set rolling mill.

>econd 3mbodiment

A rolling mill according to a second embodiment is a shi6t rolling mill in which upper and lower work rolls can be sh i6ted in the roll a4is direct ion. In this shi6t rolling

mill, as shown in 2ID>. 0 and @, an upper work roll 53is rotatably supported by a housing 51(6rames 51a, 51b) via right and le6t upper work roll chocks 52a and 52b.

An upper backup roll55

is rotatably supported by the housing51

via right and le6t upper backup roll chocks54

a and54

b, and is opposed to and contacted with theupper work roll 53. %he right and le6t upper backup roll chocks 54a and 54b are connected by connecting rods 56.

2urthermore, screw down cylinders 57a, 57b constituting a screw down device 57are provided in an upper portion o6 the housing 51and located above the upper

backup roll chocks 54a, 54b. In the screw down cylinders 57a, 57b, cylinder cases 58a, 58b are suspended and supported by suspending rods 59a, 59b at the upper

portion o6 the housing 51, and pistons 60a, 60b are supported so as to be movable upward and downward. 2lat bearings 61a, 61b are interposed between the housing

51and the cylinder cases 58a, 58b, and the cylinder cases 58a and 58b are connected together by connecting members 62. 7ower sur6aces o6 the pistons 60a, 60b are

in contact with upper sur6ace portions o6 the right and le6t upper backup roll chocks 54a and 54b. %he positions o6 these members are set such that the screw down

cylinders 57a and 57b are provided symmetrically in the a4ial direct ion with respect to the upper backup roll 55(upper work roll 53), and press the upper backup roll

55(upper work roll 53) in a laterally balanced manner via the upper backup roll chocks 54a, 54b.


14/33

%he screw down cylinders 57a, 57b, upper backup roll chocks 54a, 54b (upper backup roll 55), and upper work roll chocks 52a, 52b (upper work roll 53) are movable

in the roll a4is direction by upper shi6t cylinders 63(screw down moving means) and 64, 65(roll moving means). %he shi6t cylinders 63, 64, 65will be described

below, but since they have practically the same con6iguration, an e4planation is o66ered 6or the shi6t cylinder 63alone.

A pair o6 hydraulic cylinders 72a and 72b constituting the upper shi6t cylinder 63and symmetrical to each other are mounted on the entry side and the delivery side o6

the 6rame 51b o6 the housing 51by mounting brackets 71a and 71b. 3nd portions o6 pivotable operating levers 73a and 73b are connected to the hydraulic cylinders

72a and 72b. 5onnecting 6langes 74a, 74b are attached to the cylinder case 58b o6 the screw down cylinder 57b, and end portions o6 the connecting 6langes 74a, 74b

are in engagement with other end portions o6 the operating levers 73a, 73b. %hus, when the hydraulic cylinders 72a, 72b are synchronously actuated to pivot the

operating levers 73a, 73b in the opposite direction, the screw down cylinders 57a, 57b can be moved in the roll a4is di rection via the connecting 6langes 74a, 74b.

In the shi6t rolling mill, only the upper work roll 53, upper backup roll 55and screw down device 57provided in the upper portion o6 the housing 51have been

described. A lower work roll 75, and a lower backup roll (not shown) are provided so as to be opposed to the upper work roll 53and upper backup roll 55. %he lower

work roll 75and lower backup roll are movable in the roll a4is direction by lower shi6t cylinders (not shown) provided on the 6rame 51a.

Bhen shi6t positions o6 the upper and lower work rolls 53and 75are to be set by the above;described shi6t rolling mill o6 the present embodiment, the upper shi6t

cylinders 63, 64, 65are synchronously actuated to move the screw down cylinders 57a, 57b, upper backup roll chocks 54a, 54b and upper work roll chocks 52a, 52b

in one roll a4is direction. Bhereas the lower shi6t cylinders are synchronously actuated to move the lower backup roll chocks and lower work roll chocks in the other

roll a4is direction. , there6ore, a predetermined rolling load acts properly on the strip >, ensuring stable rolling. !ence, the

strip > can be rolled with high accuracy.

In the above;described embodiment, the upper shi6t cylinder 63is provided as the screw down moving means o6 the present invention, and the upper shi6t cylinders

64, 65are provided as the roll moving means. !owever, one shi6t cylinder may be adapted to move the screw down cylinders 57a, 57b, upper backup roll chocks 54a,54b and upper work roll chocks 52a, 52b synchronously in the roll a4is direction.

Bhen the rolling mill o6 the present invention is applied to an o66set rolling mill, the roll moving means and screw down moving means may be o66set cylinders 6or

moving the roll chocks and screw down device in the transport direction o6 the strip.

%hird 3mbodiment

In a 6our high cross rolling mi ll according to a third embodiment, 6irst balance cylinders provided at an intermediate portion o6 a housing 11push up upper backup roll

chocks 16a, 16b and an upper backup roll 18to bear their weights. Bhereas second balance cylinders provided at an upper portion o6 the housing 11suspend screw

down cylinders 20a, 20b, which constitute a screw down device 20, to bear their weights.

%hat is, as shown in 2ID>. and =, mounting brackets 81a, 81b are attached to upper portions o6 6rames 11a, 11b o6 the housing 11. >econd balance cylinders 82a,

82b are suspended 6rom and connected to the mounting brackets 81a, 81b via spherical bushes 83a, 83b. 5onnecting rods 86a, 86b are connected to drive rods 84a,

84b o6 the second balance cylinders 82a, 82b via spherical bushes 85a, 85b, and the connecting rods 86a, 86b are attached to cylinder cases 31a, 31b. /uring rolling

o6 a strip >, the second balance cylinders 82a, 82bpull up the screw down cylinders 20a, 20b to bear the weights o6 the screw down cylinders 20a, 20b, thereby

canceling out these weights so as not to a66ect the rolling accuracy o6 the strip >.

A 6lat bearing 34a and a conical roller bearing 34b are interposed between the 6rames 11a, 11b and the cylinder cases 31a, 31b, and the cylinder cases 31a and 31b are

connected together by connecting rods 35. 7ower sur6aces o6 pistons 33a and 33b are in contact with upper sur6ace portions o6 right and le6t upper backup roll chocks16a and 16b.

2irst balance cylinders 43(see 2ID. -) are mounted on intermediate portions o6 the 6rames 11a and 11b to enable the right and le6t upper backup roll chocks 16a and

16b to be pushed up. /uring rolling o6 the strip >, the balance cylinders 43push up the upper backup roll chocks 16a and 16b to bear the weights o6 the upper backup

roll chocks 16a, 16b and upper backup roll 18, thereby canceling out the weights o6 the respective devices so as not to a66ect the rolling accuracy o6 the strip >.

%he 6our high cross rolling mi ll o6 the present embodiment is also eEuipped with the same roll cross mechanisms 22, 27and hydraulic cylinder mechanisms 23, 24, 25,

28, 29as in the a6orementioned 6irst embodiment, although these mechanisms are not shown. >ince their structures and actions are practically the same, their duplicate

e4planations are omitted.

In setting the crossing angle in the cross rolling mill o6 the present embodiment described above, the upper roll cross mechanism 22and hydraulic cylinder

mechanisms 23, 24, 25are actuated, and the lower roll cross mechanism 27and hydraulic cylinder mechanisms 28, 29are also actuated. As a result, the upper work

roll 14and upper backup roll 18, and the lower work roll 15and lower backup roll 19have their a4es o6 rotation crossed, and the crossing angle can be set at apredetermined angle.

At this time, the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a are synchronously moved by the upper roll cross mechanism

22and hydraulic cylinder mechanisms 23, 24, 25via the upper crosshead 21. %hus, a positional set state in which the centers o6 the pistons 33a, 33b in the screw

down cylinders 20a, 20b align with the sha6t center o6 the upper backup roll 18(upper work roll 14) is maintained. !ence, the screw down cylinders 20a, 20bpress

the proper positions o6 the upper backup roll chocks 16a, 16b, thus preventing the occurrence o6 a tipping moment in the upper backup roll chocks 16a, 16b. Also, a

predetermined rolling load is properly imposed on the strip >, and stable rolling is per6ormed, whereby the strip > can be rolled with high accuracy.

Bhen the roll cross angle is set, the screw down cylinders 20a, 20b move together with the upper backup roll chocks 16a, 16b and upper work roll chocks 12a, 12b.

%he screw down cylinders 20a, 20b are suspended 6rom and supported by the 6rames 11a, 11b via the second balance cylinders 82a, 82b and spherical bushes 83a,


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83b, 85a, 85b. %hus, the amounts o6 hori'ontal movements o6 the screw down cylinders 20a, 20b relative to the 6rames 11a, 11b are absorbed by the spherical bushes

83a, 83b, 85a, 85b.

Bith the cross rolling mill o6 the present embodiment, as described above, the screw down cylinder 20a, upper backup roll chock 16a and upper work roll chock 12a

are synchronously moved in the same direction when the crossing angle is set. %hus, the screw down device 20presses the proper position, without destroying its

positional relationship with the upper rolls 14, 18. 5onseEuently, stable rolling takes place constantly, so that the rolling accuracy o6 the strip > can be improved, and

the decrease in the li6e o6 the screw down device 20due to partial wear can be prevented.

At this time, the amounts o6 hori'ontal movements o6 the screw down cylinders 20a, 20b relative to the 6rames 11a, 11b are absorbed by the spherical bushes 83a, 83b,85a, 85b. %hus, the property o6 the screw down cylinder 20a 6ollowing the upper backup roll chock 16a and the upper work roll chock 12a can be improved. Bhen the

strip > is rolled, the second balance cylinders 82a, 82b work, li6ting the screw down device 20(screw down cylinders 20a, 20b) and bearing its weight. !ence, the

weight o6 the screw down device 20does not adversely a66ect the rolling accuracy o6 the strip >.

Bhile the present invention has been described in the 6oregoing 6ashion, it is to be understood that the invention is not limited thereby, but may be varied in many

other ways. >uch variations are not to be regarded as a departure 6rom the spirit and scope o6 the invention, and all such modi6ications as would be obvious to one

skilled in the art are intended to be included within the scope o6 the appended claims.

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Rolling balance cylinders are primarily used in rolling mill stands to ensure that the upper work and back up rolls are maintained in position relative to the lower rolls.

%hey are also used to per6orm a secondary 6unctions as the actuators o6 the roll eccentricity compensation control system, which counters the de6ormation o6 a circular

roll into an ovali'ed 6orm due to bearing wear and improper manu6acturing and thereby creating undesirable variations in rolled strip gauge.

Work and Back Up Rolls%he rolling process can reduce the thickness o6 metal ingots (@** mm) to rol led strips o6 the desired gauge or thickness ( 0mm). %o do so, rolling mills use an

automatic gauge control system (AD5) that controls the vertical pressure applied through the work and back up rollsJ to the metal ingot or slab through pass line speed

and roll gap or gauge adFustment. %he thickness reduction is a 6unction o6 roll speed as well as the type, temperature and amount o6 rolling lubricants.

Bork and back up rolls are 6inely machined and polished to ensure a circular shape, 6 lat sur6ace 6inish, high polish, and are slight ly crowned to compensate 6or the

bending o6 the roll as rolling 6orces act upon it during the rolling process, as well as 6rom the thermal e4pansion and wear;and;tear 6rom the work rollJs normal use.

Rolls with adFustable crowns are part o6 the millJs 6latness control system. Bhile the work rolls are where the metal st rip passes through and where gauge reduction

occurs, back up rolls are used in conFunction with the work rolls to provide support, additional pressure and stability (dampening C roll de6lection) to maintain the

tight gauge tolerances and product Euality.

Hydraulic Cylinders

!ydraulic cylinders are utili'ed with the rolling millJs work roll gap positioning, roll bending, and backup roll balancing, making them part o6 a comple4 and

interrelated control system. As a discrete sub system, roll balance cylinders act on the backup roll chocks to balance the rolls and to allow them to be raised or loweredto maintain their position. In essence, they are the actuators o6 a closed loop pressure regulation. %hey act on the upper and lower working roll chocks to press them up

and down so the same roll balance and roll bending 6orce is applied. /epending on the type o6 mill stand, intermediate rolls maybe used with to provide the roll

balancing 6orces to maintain the desired gap between the work rolls. Roll balance cylinders are usually custom designed but can have bores o6 .= meters and lengths

o6 -1 meters. %hey have a variety o6 designs including, bolted, welded, tie;rod.

Bhile hydraulic roll balance cylinders have been the standard since replacing counterweight;balancing systems, it merits noting that spring cylinders have been

introduced as an option to hydraulic cylinders. >pring cylinders are designed to provide a constant 6orce during the rol ling process. %hey eliminate the need 6or

hydraulic systems and the energy use and increased maintenance (6luid leakage) associated with hydraulic cylinders. %hey are designed 6or a speci6ied range o6 loads,

roll diameters and roll gaps.

etal rolling is one o6 the most important manu6acturing processes in the modern world. %he large maFority o6 all metal products produced today are subFect to metal rolling at one

step in creating raw metal 6orms. %heingotorcontinuous castingis hot rolled into a b loom or a slab, these are the basic st ructures 6or the creation o6 a wide range o6 manu6actured

greater than @4@ inches. >labs are rectangular and are usually greater than * inches in width and more than .0 inches in thickness. Rolling is most o6ten, (particularly in the case o

per6ormed hot.


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Figure:129

Principles Of Meal Rollingost metal rolling operations are similar in that the work materia l is plastically de6ormed by compressive 6orces between two constantly spinning rolls. %hese 6orces act to red

structure. %he reduction in thickness can be measured by the di66erence in thickness be6ore and a6ter the reduction, this value is called the draft. In addition to reducing the thic

they spin in opposite directions to each other. 2riction is there6ore a necessary part o6 the rolling operation, but too much 6riction can be detrimental 6or a variety o6 reasons. It

6riction between the rolls and work material is controlled, lubricants can help with this. A basic 6lat rolling operation is shown in 6igure:9*, this manu6acturing process is bein

Figure:1!"


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/uring a metal 6orming operation, the geometric shape o6 the work is changed but its volume remains essentially the same. %he roll 'one is the area over which the rolls act on

work occurs. An important 6actor in metal rolling is, that due to the conservation o6 the volume o6 the material with the reduction in thickness, the metal e4iting the roll 'one w

%he rolls themselves rotate at a constant speed, hence at some point in the roll 'one the sur6ace velocity o6 the rolls and that o6 the material are e4actly the same. %his is terme

6aster than the material, a6ter this point the material is moving 6aster than the rolls.

Figure:1!1


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>ometimes in metal rolling practice, t ension, (6orce), is applied to a work piece as it is being rolled. %his tension may be applied to the 6ront, (6ront tension), the back, (back te

necessary to 6orm the work, and is usually used on hard to roll materials.

Figure:1!2


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#preading $n Roll For%ingIn metal rolling operations the plastic de6ormation causing a reduction in thickness will also cause an increase in the width o6 the part, this is called spreading.

Figure:1!!


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Bhen the work being processed has a high width to thickness ratio, the increase in width is relatively small and usually o6 no concern in industrial manu6acturing practice. In c

sEuare cross section, spreading can be an issue. ?ertical rolls can be employed to edge the work and maintain a constant width.

Figure:1!&


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'rain #rucure $n Meal RollingIn common industrial manu6acturing industry the ingot or continuous casting is hot rolled into a bloom or slab. In addition to producing a use6ul shape 6or 6urther processing, t

wrought grain structure. %he initial cast material will possess a non uni6orm grain structure, typically large columnar grains that grow in the direction o6 solidi6ication. %hese s

5ast structure characteristically contains many de6ects such as porosity caused by gases, shrinkage cavities, and solid inclusions o6 6oreign material that becomes trapped in th

Rolling a material above its recrystalli'ation temperature breaks apart the old grain structure and re6orms a new one. Drain boundaries are destroyed and new tougher ones are

Rolling pushes material, closing up vacancies and cavities within the metal. In addition, hot rolling breaks up inclusions and distributes their material throughout the work.

Figure:1!(


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It should be apparent that the advantages o6 metal 6orming are not Fust in the creation o6 use6ul geometric 6orms but also in the creation o6 desired material properties as well. 5

imparting strength and 6avorable grain orientation. >ince metal 6orming e66ects grain orientation, a part can be 6ormed in a way as to create grains oriented in a direction such t

parts speci6ic orientation. An e4ample o6 this can be the di66erence in grain structure between the threads o6 a machined bolt and a rolled bolt. %he 6avorable grain orientation

bene6icial to that parts application.

Figure:1!)


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Rolls For For%ingetal rolling operations can produce a wide range o6 di66erent 6ormed products. %he width o6 rolled work can be as much as several meters, or narrower than a thousandth o6 a

work over a wide range o6 thicknesses. eta l plates 6or some boilers may be rol led to a thickness o6 - inches, while 6oil 6or wrapping cigarettes and candy can be .***9 inch

and geometries. In 6lat rolling industria l manu6acture, the rolls may typically be -1 to 01 inches in diameter. In some rolling operations, in the 6orming o6 very thin work, the r

Rolls are subFect to e4treme operating conditions including, tremendous 6orces, bending moments, thermal stresses, and wear. Roll materials are selected 6or strength, rigidity,the speci6ic 6orming process. 5ommon roll materials are cast iron, cast steel, and 6orged steel. 2orged rolls are stronger and more rigid than cast rolls but are more di66icult to m

made 6rom nickel steel or molybdenum steel alloys. Bith metal rolling operations o6 certain materials, rolls made o6 tungsten carbide can provide e4treme resistance to de6lec

Roll *e+ecions>trength and rigidity are important characteristics o6 the rolls used to 6orm product in metal rolling manu6acture. %he particular at tributes o6 the rolls will e66ect dimensional ac

the rolling process great 6orces act upon the rolls. Rolls will be subFect to di66erent degrees o6 de6lection. In any particu lar rolling process, it is important to understand how the

being 6ormed. %he rolls initially start out 6lat. /uring a basic 6lat rolling operation, it can be observed that the work material will e4ert greater 6orce on the rolls towards the ce

rolls to de6lect more at the center, and hence gives the work a greater thickness in the middle.

Figure:1!,


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%o solve this problem in industrial metal rolling manu6acture, the rolls are o6ten ground so that they are thicker towards the center in such a way as to e4actly o66set the de6lect

is called camber.

Figure:1!-

%he camber that must be ground into a roll is very speci6ic to a particular work width, material, and 6orce load. A roll must usually be manu6actured 6or only one metal rolling

given temporary camber by applying 6orces through their bearings. Another way that rolls de6lect is by the shortening o6 their radius along the contact o6 the work. In other wo

de6lection is important to consider in manu6acturing practice, as it will e66ect roll radius calculations and 6riction.

*efecs $n Meal RollingA wide variety o6 de6ects are possible in meta l rolling manu6acture. >ur6ace de6ects commonly occur due to impurities in the material, scale, rust, or dirt. AdeEuate sur6ace pre

these. ost serious internal de6ects are caused by improper material distribution in the 6inal product. /e6ects such as edge cracks, center cracks, and wavy edges, are all comm

Figure:1!9


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86ten times a sheet is not de6ective, it is Fust not 6lat enough. In sheet metal industrial practice, a sheet may be passed through a series o6 leveling rolls that 6le4 the sheet in op

that can occur in 6lat rolling is alligatoring, where the work being rol led actually splits in two during the process. %he two parts o6 the work material travel in opposite directio

Figure:1&"


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In shape rolling manu6acture, a work piece will o6ten e4perience di66erent amounts o6 reduction in di66erent areas o6 its cross section. 8ne o6 the goals o6 roll pass design is to

mitigate the relative di66erences in shape change between areas, in order to avoid material de6ects. Improper reductions o6 the product can cause warping or cracking o6 the ma

warping or cracking, sometimes de6ects in the metal being 6ormed may be the reason.

Figure:1&1


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*i.eren /ypes Of Meal Rolling MillsIn metal 6orming industry, rolls themselves do not 6unction in isolation. In a metal rolling process, rolls stands, bearings, housing, motors, and other mechanical eEuipment are

place where all the eEuipment 6or metal rolling manu6acture is set up is called a rolling mill. Rolling mills o6ten vary in the type, number, and position o6 rolls. Rolling mill ar

today include the two high mill, the three high mill, the 6our high mill, the cluster mill, and the tandem rolling mill.

Figure:1&2


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In the two high reversing mill the direction o6 spin o6 the rolls can be reversed. %his enables the work to travel through in one direction, then back through in the other directio

rolls, by passing the work back and 6orth. /isadvantages o6 the two high reversing mill include the mechanical reEuirements and power to constantly overcome and reverse th

Figure:1&!


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%he three high rolling mill utili'es the principle o6 passing the work back and 6orth to achieve a series o6 reductions. $nlike the two high reversing mill, the three high mill has

elevator mechanism li6ts and lowers the work so that it can be passed back and 6orth through the rolls.

Figure:1&&


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It is known that the amount o6 roll 6orce is reduced with a smaller radius o6 the rolls. >maller radius rolls however de6lect easier and must be supported by other rolls. %he 6our

each supported by a larger backing roll.

Figure:1&(


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%he cluster mill or >end'imir mill, uses a small work roll backed up by many other rolls. %his e4tremely rigid setup is o6ten used 6or cold rolling high strength material to a ve

Figure:1&)


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%he tandem rolling mill consists o6 several stands, that the work materia l constantly passes through. At each stand the thickness o6 the work strip is reduced a certain amount. %

signi6icant. %here are technical problems associated with tandem rolling caused particularly by the 6act that the speed o6 the work material increases as it passes through each s

are used to keep the entire operation synchroni'ed. 8nce the particular technical problems and initial setup investment is overcome, tandem rolling can provide a great advant

process. %andem rolling can be even more advantageous when integrated withcontinuous casting.

Figure:1&,
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balancing cylinder

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