general guidelines for t008-design

7/25/2019 General Guidelines for T008-Design

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TARA AEROSPACE SYSTEMS LIMITED

Work Instruction/Procedure

Title:- Tool Designing and Farication !uidelines "or For# $lock

Docu#ent%u#er

FORM $LOC& !E%ERAL !'IDELI%ESRe(ision%u#er )*

E""ecti(e Date )+t,-ul. *)0Re(ision

Date 1t,-anuar.

3) SCOPE4General Guidelines for designing and fabrication of Form Blocks.

3 A$$RE5IATIO%S 'SED4

FBT - Form Block Template

T358 - Flat Pattern code

T008 - Form Block code

T005 - Form Block Templates code

Ref - Refer

Fig - Figure

Rms - Root ean !"uare

#l - #luminium

$g. - $%ample

!tk. - !tock

&g - &ilograms

mm - illimetres

'.(. - 'uter (iameter

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*3) FORM $LOC& DESI!%

*3 In6uts

Part odel) Flat Pattern *Tool code-T358+) and Process for t,ecomponent *$it,er in 'P !ketc,es or in T(' Formats+.

%ote ake sure t,at updated Reision number of part model and flat pattern,as been considered /,ile designing form block

*3* Design Considerations

*3*3 Process Stud.

Before starting an form block design process related to t,e respectie

1omponent s,ould be studied b designer as listed belo/

2o of stages in /,ic, component is formed.

aterial of t,e component. n /,ic, temper condition t,e forming is taking place.

Flange formation gien in Flat pattern is 4P6 or 4('726/,ic, in turn s,ould be in line /it, $2G (7G re"uirement) ifan flat ie/ is gien in dra/ing.

Tolerances of t,e component.

Feasibilit of t,e form block in t,e mac,ine decided b process.

2ote f process can be optimised) it ,as to be discussed in TRB *Tool

Reie/ board+ /,et,er it is alid or not and same to be

1ommunicated to respectie stake ,olders t,roug, TRB format.

*3*3* $OTTOM $LOC&

Form block mainl ,as a bottom and top blocks bet/een /,ic, t,e

1omponent is placed. T,e follo/ing are t,e design considerations for

Bottom block.

T,e important aspect to be considered /,ile designing bottom block is to

,o/ t,e component ,as to be formed i.e. /,et,er a female block is to be

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designed or a male block to be designed as bottom block.

For $%ample

Female Bottom Block

ale Bottom block

(epending on t,e component features een male and female combination

s,ould be used /,ere mostl t,e female block /ould be as bottom block.

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*3*3*3 We4

7eb is t,e core material in t,e component /,ic, is not e%posed to

t,e plactic deformation and /,ic, is taken as base for forming.

1,oosing t,e /eb is an important aspect /,ile designing t,e

female die as a bottom block. Generall t,e straig,t portion in t,e

component /,ic, is ,aing t,e ma%imum area is taken as /eb.

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... Multi6le For#ing7s in t,e sa#e stage

(epending on part configuration if t,e multiple bends are t,ere in

t,e component t,en t,e bottom block s,ould be designed in suc, a

/a t,at t,e bend /,ic, gets formed at first s,ould not effect t,e

formation of t,e ot,er flange.

n t,e aboe e%ample if a female bottom block is to be designed

taking /eb as s,o/n in aboe figure as base) formation of Flange-9

/ill effect t,e formation of 1ait as s,o/n aboe.

*3*3*38 Lug Positions in otto# lock

Form block s,ould ,ae same lug positions *location ,oles+ mentioned in

Flat patterns. 2ot onl t,e positions but diameter of ,ole in t,e lug

mentioned in t,e flat pattern s,ould also be retained /,ile deciding t,e

locating ,ole positions in form block.

T,e accurac of t,e locating ,ole positions s,ould be /it, in -0.050mm to

:0.050mm. T,e mac,ining tolerances of t,e form block s,ould be

minimum of 9;3 of component tolerances.

O6ti#ising t,e Tooling lugs

sage of t,e tooling ,oles in t,e component /eb *f an+ /ill reduce t,e

number of tooling lugs in t,e flat pattern and aoids trimming of lugs after

forming.

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n t,e aboe e%ample instead of adding t/o lugs for forming t,eflanges ,aing contour tooling ,oles can be used /,ic,optimises t,e tooling lugs.

*3*3*30 Dia#eter o" Locating Lug ,oles

(iameter of t,e lug ,oles ,as to be decided suc, t,at t,e

mac,ining inaccuracies of flat pattern ,as to be accommodated in

t,e form block. Before deciding t,e diameter of t,e pin designer

s,ould cross erif t,e tolerances in flange /idt,) bend angle and ?

tolerance for /,at nominal alue mentioned in t,e bottom block and

s,ould ,ae sliding fit /it, t,e locating pins *us,room ,eaded

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pins+

T/o different diameters of t,e ,oles to be drilled in bottom block forFool proofing*1omponent can onl be placed in one direction+.

Table-9 s,o/s different diameters used based on t,e lengt, of t,e

component.

Tale 9

(iameters of ,oles

=engt, of component (ia-9 (ia-

@8A*00mm+0.985A*3.m

m+0.98?5A*C.?m

m+

D8A*00mm+ 0.95?5A*Cmm+ 0.3A*mm+

*3*3*32 Pro"ile Cut

Profile cut to be proided as per s,eet t,ickness on top face of t,ebottom block for onl t,e female tools. aintain mm *0.0?86+ offset

from part profile as per Flat pattern *Ref Figure +.

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2mm ofset based on part

prole, step height should be


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f t,e step is not proided t,e rubber applies t,e pressure on t,e/eb in female blocks and doesnEt allo/ t,e material to flo/ into t,ecait of female block.

f t,e form block is made of #luminium allo a plastic film to be usedon t,e top of t,e bottom block to aoid friction bet/een t/o

materials and t,us allo/ing material to flo/ freel as s,o/n inbelo/.

*3*3*3: S6ring $ack

T,e tendenc of t,e material to retain its original s,ape is springback. !pring back occurs /,en t,e component tries to pull backafter forming. For e%ample if t,e flange in an s,eet metalcomponent ,as to be formed to 0 degrees after subected to aload it mig,t not result in 0degree bend instead it mig,t lead toless t,an 0degree bend. T,e form block s,ould be designed insuc, a /a t,at it accommodates t,e spring back as s,o/nbelo/.

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T,e spring back alue depends on tpe of material and tempercondition of component) pressure applied t,e alues of springback proided in anne%ure-9.

T,e ,ig,er t,e forming pressure) t,e more uniform t,e resultsobtained.

!pring back in t,e form block s,ould start from t,e mold line ass,o/n in figure

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*3*3*31 Align#ent ;oles

T,e alignment ,oles in t,e bottom block ensure t,e alignment of top and t,ebottom block. 7,en t,e load is applied on t,e block from top t,ese pins ,elpst,e top block not to disturb its position /it, respect to bottom block.

Generall t,e lug position ,oles are used as dual purpose i.e for aligning t,e

component on bottom block and for aligning t,e top plate and bottom block.

f t,e component ,as contour in t,e /eb t,en alignment ,oles /ould be gienseparatel /,ic, s,ould be press fitted in bottom block as s,o/n in figure.

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2ote #ll t,e ,oles in t,e bottom block s,ould be t,ru and t,ru if separatealignment pins are gien so t,at t,e pins can be remoed er easil.

*3*3*3+ $end Radius

T,e corner radius in t,e bottom block /,ere bend takes place s,ould bee"ual to t,at of t,e bend radius of t,e component.

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be 5mm more than ma' (ange height) *lange height maintaining standard stoc thicness




For t,e components ,aing multiple bends or /,ere t,e distancebet/een bend lines of flanges is less t,an t/o times bend radius oft,e component t,e bend radius is to be considered at =1condition i.e. least material condition.

*3*3*3< ;eig,t o" t,e otto# lock

>eig,t of t,e bottom block s,ould be 5mm more t,an ma%imum flange ,eig,tor inimum 5mm *96+. >eig,t of t,e top block s,ould be mm *0.36+ to9mm *0.5mm+. se standard stock t,icknesses *5mm) 35mm) C5mm) etc.+.*Refer figure C+

>andling t,e form block in t,e s,op floor s,ould be considered /,ile decidingt,e ,eig,t of t,e form block.

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*3*3*3) Stailit. o" t,e otto# lock

Form blocks 35mm *9.56+ in cross sectional /idt,) or narro/er) s,ould be gien step *=or T+ for stabilit *Ref Figure 5+.

*3*3*3 %o s,ar6 Corners

2o s,arp corners s,ould be present in t,e bottom block. !,arpedges s,ould ,ae a corner of R 0.956 to R 0.56 depending onlengt, of t,e bottom block.

>ig,er t,e radius on t,e top plate lesser /ould be t,e pressureon rubber b diap,ragm of t,e mac,ine.

*3*3*3* Weig,t O6ti#i=ation

7eig,t of t,e form block can be optimised b c,oosing correct

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+-ste %or narro idth-.tep %or narro idth


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lengt,) /idt, and ,eig,t of t,e form block *Bottom block andtop plate+. !ome important aspects to be considered for /eig,t

'ptimiHation.

9. 1ut-outs to be made at t,e bottom of t,e bottom blocks toreduce t,e /eig,ts if /eig,t is greater t,an 95&gs. T,esecut-outs can be s,o/n in design i.e 3( model of bottomblocks or instruction can be gien to t,e fabricator to makecut-outs. Pocket /idt, s,ould not be more t,an 00mm *86+

and t,e t,ickness at t,e pocket area s,ould be a minimumof 95mm *0.6+.

. T,e t,ickness of t,e bottom block s,ould be 5mm moret,an t,e ma%imum flange ,eig,t. T,e lengt, and /idt, oft,e bottom block s,ould not be more t,an 90mm from t,efrom t,e part boundar including t,e tooling lugs.

3. T,ickness of t,e top plate s,ould be mm /it, t,e 3mmcorner radius on all t,e edges.

C. f t,e lengt, of t,e form block is more t,an 9000mm *C06+t,en t,e material of t,e form block s,ould be taken as eit,er,lam /ood or ob rock since t,e densit is ,alf of #= allo.

*3*3*38 Li"ting #ec,anis#sf t,e /eig,t of t,e form block is more t,an 95&gs)lifting mec,anism ,as to be proided in t,e formblocks.

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't,er t,an slots in t,e bottom blocks ,inges can beproided so t,at it can be eas to lift t,e form blockand place in tra of rubber press mac,ine.

*3*3*30 Lig,tning ,ole=ig,tening ,oles are generall gien in t,e /eb of t,ecomponent as s,o/n belo/

For forming lig,tening ,oles t,e follo/ing parameters to be1onsidered

9. Bottom Block For forming t,e lig,tening ,oles t,e follo/ingpockets ,as to be created in t,e bottom blocks as s,o/nbelo/ depending on t,e part configuration.

T,e distance bet/een t,e ,ig,est point of t,e lig,tening ,olein t,e component and t,e !urface 4#E6 s,o/n aboe ,as tobe minimum of 5mm *0.6+.

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. Relief in top plate Relief to be gien in t,e top plate so t,atrubber can be flo/ into t,e pocket of t,e bottom block andform t,e lig,tening ,ole. T,e relief s,ould be minimum ofmm from t,e end of t,e bend radius line in t,e component.

3. Top punc, for t,e lig,tening ,oles /,ic, are not open atone end re"uire punc, in line /it, t,e top plate so t,atformation /ould be accurate.

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C. !pring Back Generall t,e spring back gien for lig,tening,oles /ould be t/ice of t,e spring back gien for openended flanges s,o/n in table

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/adius to be pro0ided %or all top edges o% top plate




*3*38 To6 6late Design

*3*383 %o s,ar6 Corners

2o s,arp corners s,ould be present on t,e top plate. !,arpedges s,ould ,ae a corner of R 0.956 to R 0.56 depending on

lengt, of t,e top plate.

*3*383* Clearance ,oles in to6 6late

#ll t,e component locating ,oles and alignment ,oles*f an+ int,e bottom block s,ould ,ae a clearance ,oles *T,ru >oles+ int,e top plate and t,e diameter of t,e ,oles in t,e top plates,ould be 0.00C6 more t,an t,e diameter of t,at in bottom block.

*3*3838 Material and #ac,ining tolerances o" To6 andotto# locks

aterial of bottom block s,ould be decided based ont,e lengt, and /idt,) material of t,e component. Forall aluminium allo components t,e bottom block

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s,ould be fabricated /it, aluminium allo /,ic, ise"uall or more ,arder t,an t,e component.

For e%ample if t,e component material is #l allo 0CT) t,en bottom block s,ould be fabricated /it, #=0C T material /,ic, is ,arder t,an #= 0C.

2ote #= 0C T is readil aailable in t,e market.

T,e mac,ining accuracies of t,e form block is alsobased on t,e component tolerances i.e tolerances ont,e flange angle) /eb lengt, and /idt, etc. f t,ecomponent tolerances are 0.0306 t,en t,e formblocks s,ould be mac,ined /it, 9;3rdof componenttolerance i.e. 0.0906. Flatness) parallelism tolerancess,ould be 0.0056.

f t,e form block siHe is more t,an 9meter it ispreferred to go /it, >lam /ood.

*3*3830 Locating ,oles in to6 6lateTop plate =ocating ,oles s,ould be fool proof. T,e proection of t,e top platelocating pins in t,e bottom block is 5mm *0.96+ to mm *0.36+ *Ref Figure+.

*3*3832 Set $ack!etback distance is t,e offset distance from $nd of t,e radius line to outerface of t,e top block. f t,is distance is more it mig,t create damage t,ecomponent /,ile doing ,and straig,tening. !et Back (istance s,ould be mm

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ocating pins %or part

should be protruded 3


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.et &ac istance %or +op late




*0.086+ from end of t,e radius line in bottom line for t,e top plate side profile*Ref Figure +

*3*383: Weig,t o" to6 6lateT,e /eig,t of t,e top plate is dependent on t,ickness of topplate /,ic, s,ould be mm unless an steps in t,e /ebportion of t,e component.

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.pring &ac table

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List o" RecordsSr

no

Record

Descri6tion

For#at %o Retentio

n Period

Retention

#et,od

Dis6osal

#et,od

Res6onsiil

t.

List o" Docu#entsSrno

Docu#ent

Descri6tion

Docu#ent %o Retent

ion

Period

Retention

#et,od

Dis6osal

#et,od

Res6onsiil

t.

Re(ision Record

Effective

Page

Issue

/ Rev Date

Prepared

by Approved by Revision Details

93-! 09 9?-9-095 ='I$J !#2#T #22$KR$9 #(($(

Pre6ared $. > Date C,ecked $. > Date A66ro(ed $. > Date

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//+/ 8+9: +his document is roprietar ata o% the +ara erospace .stems td) +he in%ormationcontained herein shall not be copied or reproduced, used or disclosed to others ithout the authori;ation o% +araerospace .stems td)

general guidelines for t008-design

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