Note: Descriptions are shown in the official language in which they were submitted.
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SPECIFICATION
TJTLE OF THE INVENTION
A punch-die ~et
T~CHNICAL FIEL~ OF THE INYENTION
Thi~ invent,ion r~lAtes generally to a punch-die set
u~ed ~or the p~ercing and blanking o~ sheet metal by mount-
~n8 on ~ punching pre~s, etc ., and more particularly to a
punch-dle set tha~ has been improved to ~BCi litate the
cha~lgin~ of punches and dies and to improve machining accu-
racy.
BACKaROUND OF T~ lNVENTION
A punch-die set for piercing and blanklng sheet metsl
(horoina~t~r rererred to ~s a workpiece), such a~ sheet
~teel ~ aB shown in Fig. ~ is well known.
Fi~. 5 is a longitudinal ~ectional vlew illustrating
the e88en~ial part o~ a punch-die set o~ a conventional
type. ~eference numeral 41 in the figure re~ers to a punch;
42 to a die; 43 to a die ~ixing 6crew; 44 to a dis locking
pin; 46 to a workpiece; 4ff to a set holder; 47 to a sleeve;
48 to a stripper; 49 to a punch pas~in8 hole; 50 to a ~trip-
per spring; 51 to a punch proper; 52 to a punch holder; 63
t~ a parallell~m reference plane; 54 to a punch-pro~er
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thre~ded portion; 55 to ~ parallelism re~erence ~ig plate;
56 to Q punch pusheri ~7 to a punch-pusher threaded portion;
68 to a punch head; 59 to a punch pad; and 60 to a punch-
proper æpring, respectively.
Jn Fig. 5, the stripper 48 i.~ ~ormed into a bottomed
hollow cylindrical shape, and supported on the set holder 46
vi~ the ~ripper spring 50 in such a manner as to be verti-
cally slidable in the sleeve 47 fixedly ~itted to the ~et
holder 46 ~ia adhe~ive. On the bottom of the ~tripper 48
~ormed is a punch passing hole 49 through which the punch 41
i~ pass~d.
~ he punch proper 51 ig ~ormed into a bottomed hollow
cylindria~l 3hape, and constructed 80 a~ to be vertically
~lid~bly inserted into the stripper 48. On the bottom of
the punch proper 51 ~ormed is the punch holder 52 to which
the punch 41 i~ fixedly ~itted by bonding, crimping or other
means. The punch proper 51 has the parallelism re~erence
plane ~3 ~ormed by machining part o~ the outer circum~eren-
ti~l ~urface thereof ~o as to ensure that the par~lleli~m
reference plane 53 ~lidably comes in contact with the end
face of the parallelism reference ~ig plate 55 provided on
the set holder 46. With thi~ arrangement, the rotation o~
the punch proper 51, that i.~, the punch 41 i8 controlled.
Further~ore, the punch-proper threaded portion 54 i~ provid-
ed in the form of ~emale thread~ on the inner c~rcum~eren-
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tial ~urr~ce at the uppcr end o~ the punch proper 61, Qndengaged with the punch-pusher thr~aded portion 57, which i~
provided in the form of m~le threads on the punch pu~her 56.
~hu~, the punch pusher SG is in~egrally connected to the
p~nch pr~per 51 by screwing ~he punch pusher threaded por-
tion 57 to the punch-proper threaded portion 54. The punch
pusher 56 is connected to the punch proper 51 in such a
m~nner a~ ~o push the punch pad 59. The punch pad 59 pre-
vent~ the punch 41 from coming o~f upward~, and adjusts the
punchin~ stroke by adJustlng the thicknes~ thereo~ properly.
In addltion, the punch-proper ~prin~ 60 is provided between
the p~slch pusher 36 and the stripper 48,
~ he die 42 iB installed at a location facing the punch
41 o~ the set holder 46. The die 42 is ~ixedly ~itted to
the set h~lder 46 by the die fixing screw 43, and is pre-
vented from bein8 rotated by the die lockin~ pin 44.
In the foregoing, the conætruction of the conventional
typ~ of punch-dle set as shown in Fig. 5 has been described.
In the following, the operation o~ the punch-die set of the
con~entional type wlll be described. The punch-die set i8
sot ~n ~ press tabl~, for example, and the punch head 58 i~
pushed downwards by a press or cylinder ram (not shown). As
the punch h~ad 58 is pushed downwards, the ~tripper spring
i~ ~ir~t deflected and the stripper 48 is pushed down
until the bottom surface of the stripper 48 comes ~n contact
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with the workpiece 65 because the resiliency of the ~tripper
~prin~ 50 is ~mal]er than the re61liency o~ the punch-proper
spring 60. Then, the punch-proper ~pring 60 is deflected~
and thereby the punch pusher 56 ant~ the punch proper 61 are
pushed down to a predetermined stroke. Thu~, the workpiece
placed on the die 42 is pierced or blanked by the punch
41.
In general, the shape Or piercing or blankin~ with a
punch-die ~et is not always kept constant, but may usually
be varied a~ necessary. In such a case, the punch and die
used in the punch-die ~et ha~e to be changed to a ~hape
corresponding ~o the required piercing or blanking shape.
At the ~ame tlme, the shape Or the punch passing hole pro-
vided on the stripper also has to be chan~ed.
In the prior art shown in Fi~. 5, not only the punch 41
and ~he die 42 but also the stripper 48 having the punch
passing hol~ 4g have to be changed to cope with changes in
the piercing or blanking shape. Although the replacement oi
the punch 41 and the die 42 ls not 80 difficult, the re-
pl~cement of the stripper 48 is extremely difficult~ in-
cre~sing the requlred manhours for the replacement. The
~ripper 48 not only requires large manhours ior the re-
placement, but also is diiiicult to manuiacture, requirlng
considerable manu~acturing manhours.
Furthermore, since ~he punch passing hole 49 provided
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2 ~ ~ ~'3 ~
on the bottom Or ~he stripper 48 hae to be formed in accord-
~nce with the location and sh~pe of the punch 41, it i~ not
easy ~o machine the punch passing hole 49,
Moreover, the v~rtical po~i~ions o~ the punch 41, the
punch pnSQing ho]e 49 and the die 42 and the horizontal
angular positions thereof must be accurately aligned to
improve machining accuracy.
In the prior art shown in Fig. 5, however~ the die 42
i8 fixedly fitted in ~uch a manner that the die 42 is forced
onto ~h~ set holder 46 by the die Yixin~ screw 43 while
se~ing the an~ular posit~on thereof in the hori~ontal
direction by the dle locking pin 44. Although it is seemed
that thi~ ac~urately po~ition~ vertical and horizontal an~u-
lar position~ of these components, lt i8 in ~act di~icult
to accurately po~ition them vertically or in horizontal
angular direction by merely pushing the die 42 by the die
rixin~ screw 43 to the set holder 46 because of the pregence
of sma~l ~aps among the die 42, the die ~ixin~ screw 43 and
the set holder 46. Additional ~ine adjustment is therefore
required, leadin~ to increased replacement operations.
~ISCLOSU~E OF THE INVENTION
It is an ob~ect of this invention to provide a punch-
die set that facilitates the replacement of the punches and
the dies, and 1mproves machining accuracy.
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~ 'he punch-die set o~ thi~ invention comprises a ~trip-
per that is vertlcally slidable with re8pect to a set holder
formed into a bottomed hollow ghape, a punch proper that i~
vertically slidabl.e with respect to the inner sur~aee o~ the
~tripper, a punch installed on ~he lower end of the punch
proper in such a manner as to pass through the bottom of the
~tripper, and a die disposed on the set hold~r in s~ch a
~anner as ~o ~ace the punch with a gap ~or insertin5 a
workpiece~ in which the stripper compri~es a stripper proper
formed into a hollow shape. a stripper plate detachably
ln~talled on the l~wer open end o~ the xtripper proper, ~nd
tho s~ripper plate has a punch pa~sing hole throu5h which
the punch i~ pa~s~d.
~RIEF DESCRIPTION OP TliE DRAWIN~S
Fig. 1 is a diagram illustrating the construction o~ an
embodimerlt Or thls lnvent~on.
Fig. 2 is a cross-sectional view taken along line A-A
shown in Flg. 1.
Fig. 3 is a cross-sectional v~ew taken along line B-B
shown in Fig. 1.
Fig. 4 is a peI~pective vlew o~ assistance in explain-
ing the posi~ioning means of this invention.
Fig. 5 is a diagram illu~trating the construction o~ a
punch-die ~et o~ a conventional type.
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P~EFERRED EMBODIMENl'S OF ~HIS INVENTION
Flg. 1 is a diagram illu~.ra1,in~ the con~truction o~ an
embodiment of thls lnvention. Fig. 2 i~ a cros~-s0ctional
view ta~en ~lo~ .ine ~-A shown in Fig. 1.. Fi8. 3 iB a
cross-sectional vi~w taken alon~ line B-B in Fi8. 1. Fig. 4
is a perspective view of assistance in explaining the posi-
tionin~ means o~ this i.nvention.
In Fig. 1, reference numeral 1 refers to à punch; 2 to
à die; 3 to ~ workpiece; 4 to a set holder; 5 to a sleeve; 6
to a stripper proper; 7 to a stri pper plate; 8 to a punch
passing hole; 9 to a ~tri.pper parallelism ref~renae plane;
and 11 to springs; 12 to a punch proper; 13 to a punch
holder; 14 to punch plate; 15 to a punch parallelism r~er-
ence plane; 16 to a punch head; 17 and 18 to ~ ~troke ad-
justing screw; 19 to a paralleli~m reference jig plate; 20
to a die holder; and 21 ~.o a die pad, respectively.
In the embodiment shown in Fig. 1, the ~tripper proper
6 is formed into a hollow cylindrical shape, and àdapted to
be vertically slidable in the sleeve 5 that i~ ~ixedly
fitted to the set holder 4 by means of adhesive. The strip-
per plate 7 having the punch pa~sing hole 8 through which
the punch 1 is passed is detachably installed on the lower
open end of the stripper proper 6. The stripper proper 6
ha~ the stripper parallelism reference plane 9 formed by
237~ ~a
machining par~ of the stripper proper 6 to match wil;h the
p~ralleliQm reference jig plate 19, which will be described
l~ter, ~nd i~ con~ructed so ~hat the stripper p~rallelism
reference plane 9 slidably comes ln contact with the end
face of the parsllelism reference jig plate 19 provided on
~he set holder 4 to control the rotation of the stripper
proper 6. The manner in which the rotation of the stripper
proper 6 is con~rolled will be described in more detail
later, re~erring to Fig. 3, and the manner in which the
s~ripper plate 7 is installed will be described in detail,
r~ferrin~ to Flgs. 2 and 4. The stripper proper 6 i~ sup-
por~ed on th~ set holder via the ~trippèr spring~ 10.
The punch prop~r 12 is constructed 80 that the punch
proper- 12 ls vsrtically slidably in~erted in the stripper
proper 6, and incorporat,es the punch holder 13 on the bottom
of which the punch 1 is detachably installed by adhesive or
crimping or other mean~. The punch holder 13 is detachably
supported by being pushed by the punch plate 14. The punch
proper 12 has the punch parallelism reference plane 15
~ormed by machining part o~ the outer circum~erential sur-
face thereof; the punch parallelism re~erence plane 15
being constructed so as to vertically slidably come in
contact with ~he end face o~ ~he paralleli~m re~erence jig
plate 19 to control the rotation o~ the punch proper 12~
th~t is, the punoh 1. The manner in whlch the rotation of
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th~ punch p~oper 12 i~ controlled will be in detail later,
referrin8 to Fig. 3.
Furthermore, the punch proper 12 has the p~nch head 16
formed by pr~truding on the upper end thereof~ to whiGh the
s~roke adjusting scr~ws 17 and 18 ror adJusting the punching
stroke are screwed. The punch-proper spring 11 i8 inter-
posed between ~he punch proper 12 ~nd the stripper proper 6.
The die 2 is detachably i.nstalled on the die holder 20
embedded in the se~ holder 4 via the die pad 21 in ~uch a
manner a~ ~o race the punch 1 and the s~ripper plate 7. The
manner in which the die 2 is in~talled will be described in
detail later.
In the ~oregoing, ~ construction o~ the punch-die set
o~ thi~ invention shown in Fig. 1 has been de8cribed. Now~
the construction of the essential part characterizing this
invention will be described in detail in the following,
referring t~ ~igY. 2.through 4.
Fig. 2 is a oro~s-sectional vlew ~aken along line A-A
shown in Fig. 1, which is of assistance in explaining the
manner i.n which the sl;ripper plate 7 is installed- Fig. 4
i8 a per~pec~ive view oi ass~s~ance in explaining the po8i-
tioning means (posi~ioning protrusions and positioning
receg8es ~ WhiC~l will be described later)- Numeral 22 in the
figure refers to positioning protrusions; 23 to positionlng
recesse~; 24 to a ~ixing screws; 25 ~o fixing screw holes~
2 ~ 3~3
re~pectively. Other numera}s corre~pond to like numer~ls in
Fig. 1.
In Fig. 2, the po~itioning protrusions Z2 is formed by
providing protrusion~ on the sur~ace of the stripper p].ate 7
mating with the ~tripper proper 6. The po~itioning rece~se~
23 are formed on the lower end face of the stripper proper 6
corresponding to the po4itioning protrusions 22. The~e
positioning pr~tru~ions 22 and the positioning reces~es 23
are formed by u~lng as referencex the Y axis para~lel with
the a~oremen~ioned stripper par~llelism reference plane 9
and the p~nch parallelism r~erence plane 15 (shown in Fig.
3), and t,he X ~xis orthogonally lntersecting with the Y
axis. The punch passing hole 8 formed on the stripper plate
7 ~ 8 mach~ned u~ing as references the X and Y axes. T~e
~tripper plate 7 is installed on the stripper proper 6 by
the ~ixin~ screw~ 24 after ~he positioning protrusions 22
are engaged with the poxitioning recesses 23.
In this way, the punch passing hole 8, the positioning
protru~ion~ 22, the po~i~ioning recesses 23 are m~chined
using us re~erences ~he X and Y axes. Con~equently~ when
cban~in~ ~h~ strlpper plate 7 with a new one, the punch
p~ssing hole 8 corresponding to the punch 1 i8 automatically
positioned. In Figs. Z and 4, the positioning protrusions
are provided on the stripper plate 7, and the positionia~
recesses are provided on the ~tripper proper 6. Needles to
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8~y 1 ~he poxi~ioning pro~rusions may be provided on the
stripper proper 6 and the positionin~ rece~ses on the ~trip-
per plate 7. In the followingî the~e po~itioning protru-
sion~ and ~he positioning recesses are called positioning
mean~.
Though not shown in the fi~ure, the positioning means
are provided between the die Z and the die holder 20, and
between the lower end face of the punch proper 12 and the
punch pl~e 14. As a resul~, the die '~ and the punch plate
14 can also be replaced ea~ily and with high accuracy, a~
noted above.
Flg. 3 is ~ cros~-sectional view taken along line B-B
~hown in Fig. 1 of assistance in explaining the mannsr in
which the rotation o~ the ~tripper prope~ 6 and the punch
proper 12 is corl~rolled. Like numerals in the figure corre-
s~ond to those used in Fly. 1.
In Fig. 3, the stripper parallelism re~erence plane 9
~ormed on the stripper proper 6 and the punch parallelism
reference plane 15 formed on the punch proper 12 are con-
s~ructed 80 as to slidably come in contact with the end face
oY the paralleli~m reference jig plate 19 provlded on the
set holder 4. A~ a result, the ~ripper proper 6 or the
punch proper 12 is ~revented from belng rotated even during
its vertic~l movement.
Now, the method of ~ixing the sleeve 5 and the die
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holder 20 will be descIibed. The slee~e 5 and the die
holder 20 arc ~ixedly fit1.ed to the 80t holder 4. If the
fixiog posi~ions of the sleeve 5 and the die holder 20 are
not accura~e, high-precision machining is not possible. In
this invention, ~hcrefore, the sleeve 5 and the die holder
20 are accurately positioned using a fixing jig ~not shown)
in the fo~lowing manner.
The fixing jig has such an outside diameter that the
vertically slidable with the inner circumferential
sur~ace of the ~leeve 5, and is of a cylindrical or columnar
3h~pe having on the lower end face thereo~ a positioning
mean~ corresponding to the positioning means provided on the
die holder ~. The fixing jig is inserted into the sleeve 5
downward~ from above until the jig reache~ the die holder 20
in ~he sta~e where ~ho~e other than the sleeve 5 and the die
holder 20 are not in~talled, causing ~he positioning means
o~ the fixing ji8 to match wi~h the positioning means o~ the
die holder 20. The sleeve 5 and the die holder 20 are fixed
at accura~e positlons by filling and curing adhesive in the
gap provided in advance between the sleeve 5 and the outer
circum~eren~ial surface o~ the die holder 20 and the 4et
holder 4.
In ~he foregoing, description has been made about the
con~truction of ~he punch-die set o~ this invention. Now,
~he opera~ion Or the embodiment shown in Fig. l will be
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2 ~
d~scribed in the following. The punch-di.e se~ is set on A
press table, ~or example, and the pu~ch ~rnp~r 1.2 i~ pu~hed
downw~rds by e~ertin~ a pu~hing Yorce to the stroke adjust-
in8 5crew~ 17 and 18 by a press or cylinder ram (not ~own).
As the punch proper l2 is pushed downwards, the stripper
spring lO ls first deflected, and then the entire punch
mechanism is pushed down until the stripper plate 7 comes in
cont~ct with the workpiece 3 because the resil.iency of the
stripper sprin~ lO is smal~er than the re~iliency of the
punch-proper spring ll. Then, the punch-proper sprin~ ll is
deflected, and the punch l, together with the punch proper
12, i~ pushed down by a predetermined 6troke. As a re~ult,
the workpiece 3 place~ on ~he die 2 i8 pierced or blanked by
the punch l.
Moreover, if a change has to be made in the machining
shape, eto. high-precision machining can be maintained
morely by changing the punch l, the stripper plate 7 and the
die 2, together with the punch holder 13, the punch plate
14, ~s noted earlier. Needless to say, the punching stroke
can be adjuæted by the stroke ad~sting screws 17 and 18 as
necessary.
In this invention, since the stripper comprises a
stripper proper rormed into a hollow cylindrical ~hape, and
a ~tripper plate detachably installed on the lower open end
o~ the s~ripper proper and ha~ing a punch passing hole
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through which ~he punch i~ pas~ed, t.he stripper proper need
not be replaced during the replacement of the punch. Thi~
makes thc replacement Or the punch ~y.
Furth~rmore, since positi~ning means are provided
between the stripper proper and ~he strlpper plate, between
the die and the die holder, and between the punch proper and
the punch pla~e, po~itioning in the circumferential direc-
tion can be accurately and easily carried out during t~e
replacemen~ of punches and dies, and machining accuracy can
also be lmproved.
As set forth above, this inven~ion makes it possible to
provide a punch-die 8e~ ~ in which punches and dies can be
ea~ily changed with change~ in machining shape, etc.~ and
machining accuracy can be improved.
INDUSTRIAL APPLICABILITY
As described above, the punch-dis set according to this
invention is useful a~ a punch-die set used ~or piercing and
blanking sheet metal by installing on a punchin~ press,
etc., and i~ particularly suitable as a punch-die set in
which punches and dles can be ea~ily changed and accurately
pO9 ition~d.
