Download - Inter Chang Ibility
-
8/10/2019 Inter Chang Ibility
1/20
Interchangeability andselective assembly
1/17/15Interchangeability and Selectiveassembly 1
Chirra Kumara swamy
Roll No.143503
M.Tech (MFG)
NIT ara!"al
-
8/10/2019 Inter Chang Ibility
2/20
Defnition#! i!$ercha!"ea%le &ar$ is o!e which ca! %e su%s$i$u$e' or
similar &ar$ ma!uac$ure' $o $he same 'rawi!".
he! o!e com&o!e!$ assem%les &ro&erly (a!' which sa$isies$he u!c$io!ali$y as&ec$ o $he assem%ly) wi$h a!y ma$i!"
com&o!e!$ %o$h chose! a$ ra!'om $he! i$ is *!ow! as
i!$ercha!"ea%ili$y.
+r
The &ar$s ma!uac$ure' u!'er similar co!'i$io!s %y a!y
com&a!y or i!'us$ry a$ a!y cor!er o $he worl' ca! %e
i!$ercha!"ea%le1/17/15Interchangeability and Selectiveassembly 2
-
8/10/2019 Inter Chang Ibility
3/20
,eore $he 1-$h ce!$ury &ro'uc$io! use' $o %e co!i!e' $o
small !um%er o u!i$s a!' $he same o&era$or coul' a'us$ $he
ma$i!" com&o!e!$s $o o%$ai! 'esire' i$.
/eices such as "u!s were ma'e o!e a$ a $ime %y "u!smi$h.
I si!"le com&o!e!$ o a irearm !ee'e' a re&laceme!$ $he
e!$ire irearm ei$her ha' $o %e se!$ $o a! e&er$ "u!smi$h or
cus$om re&airs or 'iscar'e' a!' re&lace' %y a!o$her irearm.
1/17/15Interchangeability and Selectiveassembly 3
HistoricalBackground
-
8/10/2019 Inter Chang Ibility
4/20
-
8/10/2019 Inter Chang Ibility
5/20
I!$ercha!"ea%ili$y o &ar$s are achiee' %y com%i!i!" a
!um%er o innovationsa!' improvementsi! machi!i!"
o&era$io!s so $ha$ we will a%le &ro'uce componentswi$h
accuracy.
Mo'er! machi!e $ools li*e !umerical co!$rol (NC) which
eole' i!$o CNC. 6i"s a!' i$ures.
Gau"es $o chec* $he accuracy o $he i!ishe' &ar$s. Thesehel&s i! ma!uac$uri!" $he com&o!e!$s wi$hi! i$s s&eciie'
limi$s.
1/17/15 I!$ercha!"ea%ili$y a!' elec$ie assem%ly 5
-
8/10/2019 Inter Chang Ibility
6/20
I a &lo$ is 'raw! o $he ac$ual 'ime!sio!s o $he
similar com&o!e!$s &ro'uce' %y a well8co!$rolle'
machi!e i$ is ou!' $o ollow Normal 'is$ri%u$io!.
1/17/15 Interchangeability and Selective assembly6
= Standard deviationxmean X/N ,!!re"#ency
-
8/10/2019 Inter Chang Ibility
7/20
eam&le we hae 100 parts each wi$h a hole a!' 100shaftswhich hae $o i$ i!$o $hese holes.
I we hae i!$ercha!"ea%ili$y $he! we ca! ma*e a!y o!e
o $he 100 shaft9 i$ i$ i!$o a!y hole 9 %e sure $ha$ $he
re:uire' i$ ca! %e o%$ai!e'.
Any M6 bolt will fit to any M6 nut randomly selected.
1/17/15Interchangeability and Selectiveassembly 7
-
8/10/2019 Inter Chang Ibility
8/20
The a'a!$a"es o i!$ercha!"ea%ili$y
1. The assem%ly o ma$i!" &ar$s is easier. i!ce a!y
com&o!e!$ &ic*e' u& rom i$s lo$ will assem%le
wi$h a!y o$her ma$i!" &ar$ rom a!o$her lo$wi$hou$ a''i$io!al i$$i!" a!' machi!i!".
;. I$ e!ha!ces $he &ro'uc$io! ra$e.
3. I$ %ri!"s 'ow! $he assem%li!" cos$ 'ras$ically.
1/17/15Interchangeability and Selectiveassembly $
-
8/10/2019 Inter Chang Ibility
9/20
4. Re&airi!" o eis$i!" machi!es or &ro'uc$s is
sim&liie' %ecause com&o!e!$ &ar$s ca! %e easily
re&lace'.
5. Re&laceme!$ o wor! ou$ &ar$s is easy.
-
8/10/2019 Inter Chang Ibility
10/20
&'am(leseys
!ouplings
"in #oints$cre%ed &asteners
'ears
!lutches
1/17/15Interchangeability and Selectiveassembly 1)
http://img.bhs4.com/12/9/1299072118b457bd117a115d0188f46f833a66c3_large.jpg -
8/10/2019 Inter Chang Ibility
11/20
Selective assemblyThe 'iscussio! so ar has %ee! i! co!!ec$io! wi$h ull
i!$ercha!"ea%ili$y or ra!'om assem%ly i! which a!y
com&o!e!$ assem%les wi$h a!y o$her com&o!e!$.
+$e! s&ecial cases o accuracy a!' u!iormi$y arises
which mi"h$ !o$ %e sa$isie' %y cer$ai! o $he i$s "ie!
u!'er a ully i!$ercha!"ea%le sys$em.
1/17/15Interchangeability and Selectiveassembly 11
-
8/10/2019 Inter Chang Ibility
12/20
or eam&le i a &ar$ a$ i$s low limi$ is assem%le' wi$h $he
ma$i!" &ar$ a hi"h limi$ $he i$ so o%$ai!e' may !o$ ully
sa$isy $he u!c$io!al re:uireme!$s o $he assem%ly.
also machi!e ca&a%ili$ies are some$imes !o$ com&a$i%le
wi$h $he re:uireme!$s o i!$ercha!"ea%le assem%ly.
1/17/15 Interchangeability and Selective assembly 12
-
8/10/2019 Inter Chang Ibility
13/20
For selec$ie assem%ly com&o!e!$s are measure' a!'
sorted intogroups by dimension &rior $o $he assem%ly&rocess. This is 'o!e or %o$h ma$i!" &ar$s.
Co!si'er a %eari!" assem%ly
7ole wi$h ha$ Cleara!ce shoul' %e 0.14mm
Ra!'omly i we $a*e a!' cleara!ce will %e 0.0-mm
7ole a!' ha$ &airi!" res&c$iely which "ies 0.14mm
cleara!ce ;4.=> a!' ;4.-3 ;5.0 a!' ;4.-
-
8/10/2019 Inter Chang Ibility
14/20
I e$remely $i"h$ (!arrow) $olera!ce ra!"es are re:uire'
i$ may !o$ &ossi%le wi$h machi!i!" o&era$io!s. I! suchcase we use selec$ie assem%ly
?i! a!' 7ole wi$h sli'i!" i$.
7ole wi$h ?i! wi$hI &i!s comi!" wi$h over size ;0.003 !ee' !o$ %e
scra& $hey ca! %e ma$e' wi$h 7oles ;0.013
ame or com&o!e!$s wi$h u!'er si@e'.
1/17/15 Interchangeability and Selective assembly 14
-
8/10/2019 Inter Chang Ibility
15/20
+rocess ca(ability
The mi!imum $olera!ce' com&o!e!$s which ca! %e
&ro'uce' o! a machi!e wi$h more $ha! ==A o
acce&$a%ili$y calle' as process capability
-0B0.1
-
8/10/2019 Inter Chang Ibility
16/20
+roblem,1For Cleara!ce Fi$
7ole Dha$D
Tolera!ce or %o$h D 0.1mm
Maimum cleara!ce D 7.E o hole 8 E.E o sha$ D ;0.18(1=.-5) D 0.;5 mm
Mi!imum cleara!ce D E.E o hole 8 7.E o sha$ D ;0.08(1=.=5) D 0.05 mm
?rocess ca&a%ili$y D 0.3Num%er o "rou&s D (&rocess ca&a%ili$y)Tolera!ce D 0.30.1D3
Ee$ $hose "rou&s %e 'e!o$e' %y # , C
1/17/15
Interchangeability and Selectiveassembly 16
Ty&e 7ole (mm) ha$ (mm)
#
,
C
Ty&e 7ole (mm) ha$ (mm)
#
,
C
-
8/10/2019 Inter Chang Ibility
17/20
Grou& C holes wi$h Grou& C sha$
7ole Tolera!ce D0.1mmha$ Tolera!ce D0.1mm
Ty&e o i$ re:uire' is cleara!ce.
Maimum cleara!ce D 7.E o hole 8 E.E o sha$
D ;0.38;0.05
D 0.;5mm
Mi!imum cleara!ce D E.E o hole 8 7.E o sha$
D ;0.;8;0.15 D 0.05mm
1/17/15Interchangeability and Selectiveassembly 17
-
8/10/2019 Inter Chang Ibility
18/20
-dvantagesThere is a lar"er !um%er o acce&$a%le &ar$s as ori"i!al
$olera!ces are "rea$er
This i! $ur! allows $he ma!uac$ure o chea&er &ar$s as
less will %e co!si"!e' $o $he was$e %i!.
elec$ie #ssem%ly assures %e$$er a!' more accura$e
assem%ly o &ar$s %y i!suri!" closer $olera!ces %e$wee!
$he ma$i!" &ar$s.
Rise $he :uali$y a!' lower ma!uac$uri!" cos$s %yavoiding tight tolerances.
Re'uces $he reec$io! ra$e (scra& ra$e)
1/17/15Interchangeability and Selectiveassembly 1$
-
8/10/2019 Inter Chang Ibility
19/20
.imitations/uri!" usa"e o $he assem%ly i o!e com&o!e!$ ails
irs$ we !ee' ma!ual o assem%ly a!' i'e!$iy $he "rou&
$o which ailure com&o!e!$ %elo!"s $o a!' search $he
com&o!e!$ i! s&are &ar$s.
,y ocusi!" o! $he i$ %e$wee! ma$i!" &ar$s ra$her $ha!
$he a%solu$e si@e o each com&o!e!$ so $here will small
'eia$io! i! si@e o com&o!e!$.
1/17/15Interchangeability and Selectiveassembly 1%
-
8/10/2019 Inter Chang Ibility
20/20
e!erences1. A text boo of production engineering ,y ?. C.
harma
!. Metrology " Measurement ,y ,ewoor3. h$$&e!.wi*i&e'ia.or"wi*iI!$ercha!"ea%&ar$s
1/17/15Interchangeability and Selectiveassembly 2)
http://en.wikipedia.org/wiki/Interchangeabpartshttp://en.wikipedia.org/wiki/Interchangeabpartshttp://en.wikipedia.org/wiki/Interchangeabpartshttp://en.wikipedia.org/wiki/Interchangeabpartshttp://en.wikipedia.org/wiki/Interchangeabparts