DESCRIPTION
TITLE OF INVENTION: SHAPING METHOD FOR BOTTOMED
CYLINDRICAL CONTAINER
TECHNICAL FIELD
[0001] The present invention relates to a shaping
method for thickening a container shoulder portion of
a bottomed cylindrical container, shaping the
container shoulder portion in a right-angle form, and
shaping a container sidewall portion in a linear form.
BACKGROUND ART
[0002] For example, a component which rotates to
perform torque transmission such as a drum, a hub, or
the like used for an automatic transmission of an
automobile, is demanded to shape a shoulder portion
which connects a bottom surface portion and a
sidewall portion perpendicular to the bottom surface
portion in a right-angle form, and to have a
sufficient thickness capable of being resistant to
torque to be transmitted. Further, the sidewall
portion is al.so demanded to have a sufficient
thickness.
[0003] Fig. 1 is a diagram illustrating a state of a
die and a bottomed cylindrical container 11 before
shaping in a conventional shaping method. In the
conventional shaping method, a container bottom
portion 1la of the bottomed cylindrical container 11
is first sandwiched by an inner punch 12 and a die 14.
Subsequently, a container sidewall portion llb
positioned in a space surrounded by the inner punch
- 1 -
12, an outer punch 13, and the die 14 is pushed to a
die bottom portion 14a side by the outer punch 13 as
illustrated in Fig. 2, thereby thickening a container
shoulder portion llc, shaping the container shoulder
portion llc in a right-angle form, and shaping the
container sidewall portion llb in a linear form.
However, in the conventional method, in the
middle of pushing a container opening end lld to the
die bottom portion 14a side by the outer punch 13,
deformation occurs in a plate thickness direction as
indicated by a dotted line in Fig. 1, and an inside
of the container shoulder portion llc is sometimes
separated from a punch shoulder portion of the inner
punch 12. In this case, there is a problem that a
flaw in a state of wrinkle (referred to as a folding
flaw, in the present application) lld formed in a
manner that a surface is folded to be overlapped with
the inside of the container shoulder portion llc
occurs, as illustrated in Fig. 2.
[00041 Patent Reference 1 discloses a shaping method
for suppressing the occurrence of folding flaw, but,
this shaping method is for shaping a container
shoulder portion in an obtuse-angle form, not in a
right-angle form. Further, in this shaping method, a
container sidewall portion is bent.
Although Patent Reference 2 discloses a shaping
method for thickening a container shoulder portion in
a right-angle form by using a pressure roller, this
shaping method requires a special device such as the
- 2 -
pressure roller.
Patent Reference 3 disc]-oses a shaping method in
which, in order to prevent a defect caused by
buckling, a vertical wall of an intermediate product
previously shaped in a cup form is subjected to
ironing by a die and a punch to form a material
accumulating portion on the vertical wall in the
vicinity of an inner periphery of a corner, and the
material accumulating portion is pressed by the punch
to move the material of the material accumulating
portion to a corner portion of an outer periphery of
the corner, thereby performing corner-making of the
outer periphery of the corner. However, this shaping
method requires special processing such that the
ironing is performed to form the material
accumulating portion, at the previous stage of the
corner-making.
Patent Reference 4 discloses a shaping method in
which, in order to provide a shaping method which
causes no flaw formed by overlapped surface at a time
of thickening a corner portion of a cylindrical cup
and shaping a bottom surface and a wall portion in a
right-angle form, when a die including a holding
punch, an upsetting punch disposed on an outer
periphery of the holding punch and capable of moving
relatively to the holding punch in an axial center
direction, and dies is used, a deep-drawn cup is
placed on the holding punch, and shaping is performed
by pushing up the holding punch and the upsetting
- 3 -
punch, each of t h e ho1.ding punch and t h e u p s e t t i n g
punch is pushed by a s t r o k e of n o t l e s s t h a n 0 . 5
t i m e s nor more t h a n 0.7 t i m e s a f u l l s t r o k e of each
of t h e punches ( f i r s t s t e p ) , o n l y t h e h o l d i n g punch
is s u c c e s s i v e l y pushed b y a s t r o k e of n o t l e s s t h a n
0 . 8 times n o r more t h a n 0 . 9 t i m e s t h e f u l l s t r o k e of
t h e h o l d i n g punch ( s e c o n d s t e p ) , and t h e h o l d i n g
punch and t h e u p s e t t i n g punch a r e s u c c e s s i v e l y pushed
t o t h e i r f u l l s t r o k e s ( t h i r d s t e p ) , t h e r e b y
p e r f o r m i n g s h a p i n g . However, i n t h i s s h a p i n g method,
t h e r e i s a need t o move t h e h o l d i n g punch and t h e
u p s e t t i n g punch t o t h e p o s i t i o n s i n t h e f i r s t t o
t h i r d s t e p s , and t h r e e s t e p s a r e r e q u i r e d i n a normal
d o u b l e a c t i o n p r e s s machine. F u r t h e r , i n o r d e r t o
c o n t i n u o u s l y conduct t h e f i r s t t o t h i r d s t e p s i n one
p r e s s machine, an e x p e n s i v e d o u b l e a c t i o n s e r v o p r e s s
machine is r e q u i r e d .
CITATION LIST
PATENT REFERENCE
[0005] P a t e n t R e f e r e n c e 1: J a p a n e s e Laid-open P a t e n t
P u b l i c a t i o n No. 2001-47175
P a t e n t R e f e r e n c e 2: J a p a n e s e Laid-open p a t e n t
P u b l i c a t i o n No. 2007-289989
P a t e n t R e f e r e n c e 3 : J a p a n e s e Laid-open P a t e n t
P u b l i c a t i o n No. 09-327749
P a t e n t R e f e r e n c e 4 : J a p a n e s e Laid-open Pat-ent.
P u b l i c a t i o n No. 2014-91146
SUMMARY OF I N V E N T I O N
TECHNICAL PROBLEM
[0006] The present invention has been made based on
the above-described circumstances, and an object
thereof is to allow thickening of a container
shoulder portion of a bottomed cylindrical container,
shaping of the container shoulder portion in a rightangle
form, and shaping of a container sidewall
portion in a linear form while suppressing occurrence
of a folding flaw, without requiring a special device
and special processing at a previous stage.
SOLUTION TO PROBLEM
[ 0 0 0 7 ] The gist of the present invention for solving
the above-described problem is as follokis.
[ I ] A shaping method for a bottomed cylindrical
container having a container bottom portion, a
container sidewall portion, and a curved container
shoulder portion connecting the container bottom'
portion and the container sidewall portion, taken as
a workpiece, by using:
an inner punch;
an annular first outer punch disposed along an
outer periphery of the inner punch, and having a
rounded punch. shoulder portion in an outer edge
portion thereof in a direction orthogonal to a center
axis of a press surface portion;
an annular second outer punch disposed along an
outer periphery of the first outer punch, and with
which a container opening end of the bottomed
cylindrical container is pushed; and
a die having a die bottom portion and a die
-- 5 -
sidewall portion vertically connected to an outer
edge portion of the die bottom portion, and disposed
to face the inner punch, the first outer punch, and
the second outer punch, wherein
center axes of the inner punch, the first outer
punch, the second outer punch, and the die are
arranged coaxially, the method including a step of
relatively moving the first outer punch and the
second outer punch toward the die bottom portion of
the die in a state where the container bottom portion
is sandwiched by the inner punch and the die, and a
state where the container opening end is bound by a
sidewall portion of the first outer punch and the die
sidewall portion of the die, to thicken the container
shoulder portion, 'shape the container shoulder
portion in a right-angle form, and shape the
container sidewall portion in a linear form in a
direction along the center axis.
[ 2 ] The shaping method for the bottomed
cylindrical container according to [I], wherein the
first outer punch and the second outer punch are
formed as a single annular punch in which a stepped
trench portion provided continuously to the press
surface portion via the rounded punch shoulder
portion is formed, and the container opening end of
the bottomed cylindrical container is pushed by a
bottom surface portion of the stepped trench portion.
[ 3 ] The shaping method for the bottomed
cylindrical container according to [I] or [2],
- 6 -
wherein a t a same time a s o r a f t e r c o n t a c t of t h e
rounded punch s h o u l d e r p o r t i o n w i t h r e s p e c t t o t h e
c o n t a i n e r s h o u l d e r p o r t i o n , t h e second o u t e r punch
a b u t s a g a i n s t and pushes t h e c o n t a i n e r o p e n i n g e n d .
[ 4 ] The s h a p i n g method f o r t h e bottomed
c y l i n d r i c a l c o n t a i n e r a c c o r d i n g t o [I], f u r t h e r
i n c l u d i n g
a p o s t s t e p of t h i c k e n i n g t h e c o n t a i n e r s i d e w a l l
p o r t i o n of t h e bottomed c y l i n d r i c a l c o n t a i n e r shaped
i n t h e s t e p , i n a p l a t e t h i c k n e s s d i r e c t i o n , by
u s i n g :
a t h i c k e n i n g i n n e r punch;
an a n n u l a r t h i c k e n i n g o u t e r punch d i s p o s e d a l o n g
an o u t e r p e r i p h e r y of t h e t h i c k e n i n g i n n e r punch; and
a t h i c k e n i n g d i e having a d i e bottom p o r t i o n and
a d i e s i d e w a l l p o r t i o n v e r t i c a l l y c o n n e c t e d t o an
o u t e r edge p o r t i o n of t h e d i e bottorn p o r l i o n , and
d i s p o s e d t o f a c e t h e t h i c k e n i n g i n n e r punch and t h e
t h i c k e n i n g o u t e r punch, w h e r e i n :
c e n t e r a x e s of t h e t h i c k e n i n g i n n e r punch, t h e
t h i c k e n i n g o u t e r punch, and t h e t h i c k e n i n g d i e a r e
a r r a n g e d c o a x i a l l y ; and
t h e p o s t s t e p i n c l u d e s a s t e p of
r e l a t i v e l y moving t h e t h i c k e n i n g o u t e r punch
d i s p o s e d i n a gap b e i n g a gap between t h e t h i c k e n i n g
i n n e r punch and t h e d i e s i d e w a l l p o r t i o n of t h e
t h i c k e n i n g d i e and l a r g e r t h a n t h e p l a t e t h i c k n e s s of
t h e c o n t a i n e r s i d e w a l l p o r t i o n , toward t h e d i e bottom
p o r t i o n of t h e t h i c k e n i n g d i e , i n a s t a t e where t h e
- 7 -
container bottom portion i.s sandwiched by the
thickening inner punch and the thickening die, to
upset the container sidewall portion and thicken the
container sidewall portion in the plate thickness
direction.
[5] The shaping method for the bottomed
cylindrical container according to [ 4 ] , wherein
a shape of a punch shoulder portion of the
thickening inner punch is equal to a shape of the
rounded punch shoulder portion in the first step.
ADVANTAGEOUS EFFECTS OF INVENTION
[ 0 0 0 8 ] According to the present invention, it is
possible to thicken a container shoulder portion of a
bottomed cylindrical container, shape the container
shoulder portion in a right-angle form, and shape a
container sidewall portion in a linear form while
suppressing occurrence of a folding flaw, without
requiring a special device and special processing at
a previous stage.
BRIEF DESCRIPTION OF DRAWINGS
[ 0 0 0 9 ] [Fig. 11 Fig. 1 is a cross-sectional view
illustrating a die and a bottomed cylindrical
container before shaping in a conventional shaping
method.
[Fig. 21 Fig. 2 is a cross-sectional view
illustrating the die and the bottomed cylindrical
container after the shaping according to the
conventional shaping method.
[Fig. 31 Fig. 3 is a cross-sectional view
- 8 -
ilLustrating a die and a bottomed cylindrical
container before shaping in a first step according to
an embodiment.
[Fig. 41 Fig. 4 is a cross-sectional view
illustrating the die and the bottomed cylindrical
container during the shaping in the first step
according to the embodiment.
[Fig. 51 Fig. 5 is a cross-sectional view
illustrating the die and the bottomed cylindrical
container during the shaping in the first step
according to the embodiment.
[Fig. 61 Fig. 6 is a cross-sectional view
illustrating the die and the bottomed cylindrical
container during the shaping in the first step
according to the embodiment.
[Fig. 71 Fig. 7 is a cross-sectional view
illustrating the die and the bottomed cylindrical
container during the shaping in the first step
according to the embodiment.
[Fig. 81 Fig. 8 is a cross-sectional view
illustrating the die and the bottomed cylindrical
container after the shaping in the first step
according to the embodiment.
[Fig. 91 Fig. 9 is a cross-sectional view
illustrating a die and a bottomed cylindrical
container before shaping in a second step according
to the embodiment.
[Fig. 101 Fig. 10 is a cross-sectional view
illustrating the die and the bottomed cylindrical
- 9 -
container during the shaping in the second step
according to the embodiment.
[Fig. 111 Fig. 11 is a cross-sectional view
illustrating the die and the bottomed cylindrical
container after the shaping in the second step
according to the embodiment.
[Fig. 121 Fig. 12 is a cross-sectional view
illustrating a die and a bottomed cylindrical
container before shaping in a comparative example.
[Fig. 13A1 Fig. 13A is a cross-sectional view
illustrating the die and the bottomed cylindrical
container during the shaping in the comparative
example.
[Fig. 1381 Fig. 138 is an enlarged crosssectional
view illustrating the die and the bottomed
cylindrical container during the shaping in the
comparative example.
[Fig. 14Al Fig. 14A is a cross-sectional view
illustrating the die and the bottomed cylindrical
container during the shaping in the comparative
example.
[Fig. 14Bl Fig. 148 is an enlarged crosssectional
view illustrating the die and the bottomed
cylindrical container during the shaping in the
comparative example.
fFig. 15A] Fig. 15A is a cross-sectional view
illustrating the die and the bottomed cylindrical
container after the shaping in the comparative
example.
- l o -
[Fig. 1581 Fig. 158 is an enlarged crosssectional
view illustrating the die and the bottomed
cylindrical container after the shaping in the
comparative example.
[Fig. 161 Fig. 16 is a cross-sectional view
illustrating a die and a bottomed cylindrical
container before shaping in a first step according to
a modified example.
DESCRIPTION OF EMBODIMENTS
[0010] Hereinafter, embodiments for carrying out the
present invention will be described with reference to
the attached drawings.
A shaping method for a bottomed cylindrical
container according to the present embodiment
includes: a first step of thickening a container
shoulder portion of the bottomed cylindrical
container, shaping the container .shoulder portion in
a right-angle form, and shaping a container sidewall
portion in a linear form by using a first press die;
and a second step of thickening, after the first step,
the container sidewall portion in a plate thickness
direction by using a second press die.
[00111 (First step)
Fig. 3 is a cross-sectional view illustrating a
die (first press die) and a bottomed cylindrical
container before shaping in a first step according to
an embodiment. Note that side cross sections of the
first press die and a later-described second press
die are axisymmetric, so that only one-side part from
- 11 -
a center axis is illustrated. The same applies to
the other drawings.
[0012] A target to be shaped (workpiece) of a press
machine in the first step is a bottomed cylindrical
container 21 having a container bottom portion 21a, a
container sidewall portion 21b, and a curved
container shoulder portion 21c connecting the
container bottom portion 21a and the container
sidewall portion 21b. The bottomed cylindrical
container 21 being the workpiece is one shaped
beforehand by drawing.
100131 The first press die has an inner punch 22, an
outer punch 23, a knockout 24, and a die 25, whose
center axes 20 are arranged coaxially. The die 25 is
of fixed type, and other elements 22 and 23 can be
raised and lowered by a raising and lowering
mechanism. For the raising and lowering mechanism, a
hydraulic one, a servomotor, or the like can be used.
Further, since the inner punch 22 is only required to
be able to sandwich the container bottom portion 21a
with the die 25, a spring or the like which gives
biasing force in a direction of the die 25, can be
used for the inner punch 22.
[00141 The inner punch 22 has a columnar shape, and
has a press surface portion 22a in a flat state
facing the knockout 24 and the die 25, and an outer
peripheral surface portion 22b.
[00151 The outer punch 23 is annularly formed, and
disposed along the outer peripheral surface portion
- 12 -
22b of the inner punch 22. The outer punch 23 has a
first press surface portion 23a in an annular shape
in a plan view which faces the die 25, and an outer
peripheral surface portion 23b. In an outer edge
portion in a radial direction orthogonal to the
center axis 20 of the first press surface portion 23a,
an annular stepped trench portion 23c is formed. The
stepped trench portion 23c has a sidewall portion 23d
in a circumferential shape, and a bottom surface
portion (referred to as second press surface portion)
23e in an annular shape in a plan view orthogonal to
the sidewall portion 23d. The sidewall portion 23d
and the first press surface portion 23a are connected
by a rounded punch shoulder portion 23f. An outside
diameter of the sidewall portion 23d of the stepped
trench portion 23c is approximately the same as an
inside diameter of the container sidewall portion 21b
of the bottomed cylindrical container 21.
[0016] The knockout 24 having a columnar shape, is
for removing the bottomed cylindrical container 21
shaped by the first press die from the first press
die, and is movable and capable of being raised and
lowered by a mechanical driving source whose
illustration is omitted.
[0017] The die 25 has a die bottom portion 25a, and
an annular die sidewall portion 25b vertically
connected to an outer edge portion of the die bottom
portion 25a. At a center of the die bottom portion
25a, a hole portion 25c in which the knockout 24 is
- 13 -
disposed, is formed. An inside diameter of the die
sidewall portion 25b is approximately the same as an
outside diameter of the container sidewall portion
21b.
[0018] Hereinafter, the first step will be described.
In the first step, a press machine makes the
inner punch 22 lower with respect to the bottomed.
cylindrical container 21 placed on the die 25 so that
the container bottom portion 21a is sandwiched by the
inner punch 22 and the die 25, and makes the outer
punch 23 lower while keeping this state.
[0019] As illustrated in Fig. 3, the outer punch 23
is lowered, and a container opening end 21d of the
bottomed cylindrical container 21 is entered an
inside of the stepped trench portion 23c of the outer
punch 23. At this time, the container opening end
21d is separated from the second press surface
portion 23e of the outer punch 23, and is bound from
directions orthogonal to the center axis 20 by the
stepped trench portion 23c and the die sidewall
portion 25b.
A s illustrated in Fig. 4, when the outer punch 23
is further lowered, the punch shoulder portion 23f is
brought into contact with the container shoulder
portion 21c, and the container shoulder portion 21c
and the container sidewall portion 21b are deformed
downward. Note that although it is described that
the container bottom portion 21a is previously
sandwiched by the inner punch 22 and the die 25, it
- 14 -
is only required that the container bottom portion
21a is sandwiched when the punch shoulder portion 23f
is brought into contact with the container shoulder
portion 21c. Specifically, it is also possible to
set that the container bottom portion 21a is
sandwiched by the inner punch 22 and the die 25 at a
timing same as or right before the contact of the
punch shoulder portion 23f with respect to the
container shoulder portion 21c.
[0020] As illustrated in Fig. 5, when the outer
punch 23 is further lowered, the second press surface
portion 23e of the stepped trench portion 23c abuts
against the container opening end 21d, and the
container shoulder portion 21c and the container
sidewall portion 21b are deformed downward in a state
where the container opening end 21d is pressed by the
second press surface portion 23e. Specifically, it
is designed such that at a timing same as or after
the contact of the punch shoulder portion 23f with
respect to the container shoulder portion 21c, the
second press surface portion 23e of the stepped
trench portion 23c abuts against and pushes the
container opening end 21d.
[0021] As illustrated in Fig. 6 and Fig. 7, when the
outer punch 23 is further lowered, the container
shoulder portion 21c is gradual-ly pushed toward a die
corner portion 25d being a boundary between the die
bottom portion 25a and the die sidewall portion 25b,
resulting in that a portion on the container shoulder
-- 15 -
portion 21c side of the container bottom portion 21a
is thickened. At this time, a contact range of the
punch shoulder portion 23f and the bottomed
cylindrical container 21 expands in a direction of
the first press surface portion 23a of the outer
punch 23, which enables to prevent occurrence of a
folding flaw on the bottomed cylindrical container 21
at the punch shoulder portion 23f. In other words,
since the container sidewall portion 21b, the
container shoulder portion 21c, and the container
bottom portion 21a are shaped while restraining the
deformation in the plate thickness direction of the
container sidewall portion 21b, and while making the
punch shoulder portion 23f closely bring into contact
with the contai.ner shoulder portion 21c, it is
possible to suppress the folding flaw from occurring
on the inside of the container shoulder portion 21c.
100221 From the state illustrated in Fig. 7, the
outer punch 23 is further lowered. At this time, the
container sidewall portion 21b is pushed by the
second press surface portion 23e of the outer punch
23, and in addition to that, the thickened portion on
the container shoulder portion 21c side of the
container bottom portion 21a is pressed downward by
the first press surface portion 23a and the punch
shoulder portion 23f, to thereby make a material of
the thickened portion of the container bottom portion
21a flow in a space of the die corner portion 25d to
thicken the container shoulder portion 21c and shape
- 16 -
the container shoulder portion 21c in a right-angle
form.
KO0231 Through the above-described first step, it is
possible to thicken the container shoulder portion
21c, shape the container shoulder portion 2lc in a
right-angle form, and form the container sidewall
portion 21b in a linear form in a direction along the
center axis 20. After performing the shaping through
the first step, the press machine raises the inner
punch 22, the outer punch 23, and the knockout 24,
and removes the bottomed cylindrical container 21
from the die 25.
[0024] (Second step)
Fig. 9 is a cross-sectional view illustrating a
die (second press die) and a bottomed cylindrical
container before shaping in a second step according
to the embodiment.
A target to be shaped (workpiece) of a press
machine in the second step is the bottomed
cylindrical container shaped in the first step, and
in the description hereinbelow, a reference numeral
of the bottomed cylindrical container shaped in the
first step is set to 31, and respective portions of
the bottomed cylindrical container 31 are described
as a container bottom portion 3la, a container
sidewall portion 31b, a container shoulder portion
31c, and a container opening end 31d.
[0025] The second press die has an inner punch 32
(thickening inner punch), an outer punch 33
- 17 -
(thickening outer punch), a knockout 34, and a die 35
(thickening die), whose center axes 30 are arranged
coaxially. The die 35 is of fixed type, and other
elements 32 and 33 can be raised and lowered by a
raising and lowering mechanism. For the raising and
lowering mechanism, a hydraulic one, a servomotor, or
the like can be used. Further, since the inner punch
32 is only required to be able to sandwich the
container bottom portion 31a with the die 35, a
spring or the like which gives biasing force in a
direction of the die 35, can be used for the inner
punch 32.
[0026] The inner punch 32 has a columnar shape, and
has a press surface portion 32a in a flat state
facing the knockout 34 and the die 35, an outer
peripheral surface portion 32b, and an inner punch
shoulder portion 32c connecting the flat surface
portion 32a and the outer'peripheral surface portion
32b. An outside diameter of the outer peripheral
surface portion 32b of the inner punch 32 is
approximately the same as an inside diameter of the
container sidewall portion 31b of the bottomed
cylindrical container 31. Further, a shape of the
inner punch shoulder portion 32c is approximately the
same as a shape of the punch shoulder portion 23f of
the outer punch 23 used in the first step.
[0027] The outer punch 33 is annularly formed, and
disposed along the outer peripheral surface portion
32b of the inner punch 32. The outer punch 33 has a
-- 18 -
press surface portion 33a in an annular shape in a
plan view which faces the die 35. A thickness
(thickness in a direction orthogonal to the center
axis 30) of the outer punch 33 is larger than a plate
thickness T of the container sidewall portion 31b.
[00281 The knockout 34 having a columnar shape, is
for removing the bottomed cylindrical container 31
shaped by the second press die from the second press
die, and is movable and capable of being raised and
lowered by a mechanical driving source whose
illustration is omitted.
[0029] The die 35 has a die bottom portion 35a, and
an annular die sidewall portion 35b vertically
connected to an outer edge portion of the die bottom
portion 35a. At a center of the die bottom portion
35a, a hole portion 35c in which the knockout 34 is
disposed, is formed. An inside diameter of the die
sidewall portion 35b is larger than an outside
diameter of the container sidewall portion 31b, in
order to thicken the container sidewall portion 31b.
Specifically, there is formed a gap between the
container sidewall portion 31b and the die sidewall
portion 35b. An interval S1 between the die sidewall
portion 35b and the inner punch 32 is larger than the
plate thickness T of the container sidewall portion
31b, and the outer punch 33 is disposed in the gap S1
[0030] Hereinafter, the second step will be
described.
In the second step, the press machine makes the
- 19 -
inner punch 32 lower with respect to the bottomed
cylindrical container 31 placed on the die 35 so that
the container bottom portion 31a is sandwiched by the
inner punch 32 and the die 35, and makes the outer
punch 33 lower while keeping this state.
[0031] As illustrated in Fig. 10 and Fig. 11, the
outer punch 33 is lowered to upset the container
sidev~all portion 31b and thicken the portion in the
plate thickness direction in a space surrounded by
the inner punch 32, the outer punch 33, and the die
35.
LO0321 At this time, since the container shoulder
portion 3lc is shaped in a form such that it is
brought into contact with the inner punch shoulder
portion 32c, and in addition to that, it is shaped in
a right-angle form in the first step, the container
shoulder portion 31c never separates from the inner
punch shoulder portion 32c in the middle of the
second step. For this reason, it is possible to
suppress the occurrence of the folding flaw on the
inside of the container shoulder portion 31c.
[0033] Through the above-described second step, it
is possible to thicken the container sidewall portion
31b in the plate thickness direction. After
performing the shaping through the second step, the
press machine raises the inner punch 32, the outer
punch 33, and the knockout 34, and removes the
bottomed cylindrical container 31 from the die 35.
[0034] As a comparative example, a case where the
- 20 -
second step is carried out in a state where a
container shoulder portion is not shaped in a rightangle
form, as illustrated in Fig. 12, will be
described. Note that a reference numeral of a
bottomed cylindrical container is set to 41, and
respective portions of the bottomed cylindrical
container '41 are described as a container bottom
portion 41a, a container sidewall portion 41b, a
container shoulder portion 41c, and a container
opening end 41d.
In this case, in the middle of the second step, a
gap S2 is generated between the inner punch shoulder
portion 32c and the container shoulder portion 41c,
as illustrated in Fig. 13A and Fig. 138. Further, in
the gap 5 2 , a material of the bottomed cylindrical
container 41 bulges out, resulting in that a folding
flaw 41e occurs on the inside of the container
shoulder portion 41c, as ill.ustrated in Fig. 14A, Fig.
148, Fig. 15A, and Fig. 15B. Therefore, there is a
need to conduct, in the first step, the thickening
processing until when the container shoulder portion
41c is shaped in a right-angle form.
[00351 For the bottomed cylindrical container 21, it
is possible to employ various publicly-known
materials capable of being subjected to plastic
working, such as metals of steel, aluminum, and body,
or alloys of these.
Further, although it is described that the
bottomed cylindrical container 21 is shaped
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beforehand by the drawing, it is also possible to
design such that the bottomed cylindrical container
21 is shaped from a material of flat plate by using
the die 25, for example, of the first press die, as a
preceding step of the first step, for example.
100361 In the foregoing, the present invention has
been described together with various embodiments, but,
the present invention is not limited only to these
embodiments, and a modification and the like can be
made within the range of the present invention.
(Modified example 1)
Although the above-described embodiment describes
the example in which in the first press die, the
outer punch 23 is formed as a single annular punch in
which the stepped trench portion 23c provided
continuously to the press surface portion 23a via the
rounded punch shoulder portion 23f is formed, and the
bottom surface portion 23e of the stepped trench
portion 23c pushes the container opening end 21d of
the bottomed cylindrical container 21, the present
invention is not limited to the example. It is also
possible to employ a configuration such that the
outer punch 23 is divided into an annular first outer
punch 231 disposed along an outer periphery of the
inner punch 22, and having the rounded punch shoulder
portion 23f in an outer edge portion in a direction
orthogonal to the center axis 20 of the press surface
portion 23a, and an annular second outer punch 230
disposed along an outer periphery of the first outer
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punch 231, and used for pushing the container opening
end 21d of the bottomed cylindrical container 21, as
illustrated in Fig. 16. However, it is suitable to
form the outer punch 23 as a single punch, also from
a viewpoint that it is required to prepare only one
raising and lowering mechanism.
[00371 (Modified example 2)
In the above-described embodiment, the outer
punch 23 is lowered in the state where the inner
punch 22, the knockout 24, and the die 25 are fixed,
to shape the container shoulder portion 21c in the
right-angle form while thickening the container
shoulder portion 21c in the first step, but, the
present invention is not limited to the above.
Specifically, it is also possible that in the first
step, the outer punch 23 is fixed, and the inner
punch 22, the knockout 24, and the die 25 are raised
to shape the container shoulder portion 21c in the
right-angle form while thickening the container
shoulder portion 21c. Further, it is also possible
to shape the container shoulder portion 21c in the
right-angle form while thickening the container
shoulder portion 21c by raising the inner punch 22,
the knockout 24, and the die 25, while lowering the
outer punch 23.
[0038] (Modified example 3)
In the above-described embodiment, the outer
punch 33 is lowered in the state where the inner
punch 32, the knockout 34, and the die 35 are fixed,
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to thicken the container sidewall portion 21b in the
second step, but, the present invention is not
limited to the above. Specifically, it is also
possible that in the second step, the container
sidewall portion 21b is thickened by raising the
inner punch 32, the knockout 34, and the die 35 in a
state where the outer punch 33 is fixed. Further, it
is also possible that the container sidewall portion
21b is thickened by raising the inner punch 32, the
knockout 34, and the die 35 while lowering the outer
punch 33.
[00391 (Modified example 4)
In the above-described embodiment, the top and
bottom of the respective tools may be reversed.
Further, although the knockouts 24 and 34 are
provided in the above-described embodiment, the
knockouts 24 and 34 can also be omitted. In this
case, it is also possible that the hole portion 25a
of the die 25 is omitted, and the entire container
bottom portion 21a is supported by the die 25.
Further, it is also possible that the hole portion
35c of the die 35 is omitted, and the entire
container bottom portion 31a is supported by the die
35. The bottomed cylindrical container after being
subjected to the first step or the second step may
also be removed from the die 25 or 35 by using a
pulling machine, for example.
INDUSTRIAL APPLICABILITY
[0040] The present invention can be used for shaping
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a bottomed cylindrical container to he a component
which rotates to perform torque transmission such as
a drum or a hub used for an automatic transmission of
an automobile, for example.
CLAIMS
[Claim 11 A shaping method for a bottomed
cyli-ndrical container having a container bottom
portion, a container sidewall portion, and a curved
container shoulder portion connecting the container
bottom portion and the container sidewall portion,
taken as a workpiece, by using:
an inner punch;
an annular first outer punch disposed along an
outer periphery of the inner Gunch, and having a
rounded punch shoulder portion in an outer edge
portion thereof in a direction orthogonal to a center
axis of a press surface portion;
an annular second outer punch disposed along an
outer periphery of the first outer punch, and with
which a container opening end of the bottomed
cylindrical container is pushed; and
a die having a die bottom portion and a die
sidewall portion vertically connected to an outer
edge portion of the die bottom portion,and disposed
to face the inner punch, the first outer punch, and
the second outer punch, wherein
center axes of the inner punch, the first outer
punch, the second outer punch, and the die are
arranged coaxially, the method comprising a step of
relatively moving the first olit.er punch and the
second outer punch toward the die bottom portion of
the die in a state where the container bottom portion
is sandwiched by the inner punch and the die, and a
- 26 -
state where the container opening end is bound by a
sidewall portion of the first outer punch and the die
sidewall portion of the die, to thicken the container
shoulder portion, shape the container shoulder
portion in a right-angle form, and shape the
container sidewall portion in a linear form in a
direction along the center axis.
[Claim 21 The shaping method for the bottomed
cylindrical container according to claim 1, wherein
the first outer punch and the second outer punch
are formed as a single annular punch in which a
stepped trench portion provided continuously to the
press surface portion via the rounded punch shoulder
portion is formed, and the container opening end of
the bottomed cylindrical container is pushed by a
bottom surface portion of the stepped trench portion.
[Claim 31 The shaping method for the bottomed
cylindrical container according to claim 1 or 2,
wherein
at a same time as or after contact of the rounded
punch shoulder portion with respect to the container
shoulder portion, the second outer punch abuts
against and pushes the container opening end.
[Claim 41 The shaping method for the bottomed
cylindrical container according to claim 1, further
comprising
a post step of thickening the container sidewall
portion of the bottomed cylindrical container shaped
in the step, in a plate thickness direction, by
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u s i n g : .
a t h i c k e n i n g i n n e r punch;
an a n n u l a r t h i c k e n i n g o u t e r punch d i s p o s e d a l o n g
an o u t e r p e r i p h e r y of t h e t h i c k e n i n g i n n e r punch; and
a t h i c k e n i n g d i e h a v i n g a d i e bottom p o r t i o n and
a d i e s i d e w a l l p o r t i o n v e r t i c a l l y c o n n e c t e d . t o an
o u t e r edge p o r t i o n of t h e d i e bottom p o r t i o n , and
d i s p o s e d t o f a c e t h e t h i c k e n i n g i n n e r punch and t h e
t h i c k e n i n g o u t e r punch, w h e r e i n :
c e n t e r a x e s of t h e t h i c k e n i n g i n n e r punch, t h e
t h i c k e n i n g o u t e r punch, and t h e t h i c k e n i n g d i e a r e
a r r a n g e d c o a x i a l l y ; and ,
t h e p o s t s t e p i n c l u d e s a s t e p of
r e l a t i v e l y moving t h e t h i c k e n i n g o u t e r punch
d i s p o s e d i n a gap b e i n g a gap between t h e t h i c k e n i n g
i n n e r punch and t h e d i e s i d e w a l l p o r t i o n of t h e
t h i c k e n i n g d i e and l a r g e r t h a n a p l a t e t h i c k n e s s of
t h e c o n t a i n e r s i d e w a l l p o r t i o n , toward t h e d i e bottom
p o r t i o n of t h e t h i c k e n i n g d i e , i n a s t a t e where t h e
c o n t a i n e r bottom p o r t i o n is sandwiched by t h e
t h i c k e n i n g i n n e r punch and t h e t h i c k e n i n g d i e , t o
u p s e t t h e c o n t a i n e r s i d e w a l l p o r t i o n and t h i c k e n t h e
c o n t a i n e r s i d e w a l l p o r t i o n i n t h e p l a t e t h i c k n e s s
d i r e c t i o n .
[Claim 51 The s h a p i n g method f o r t h e bottomed
c y l i n d r i c a l c o n t a i n e r a c c o r d i n g t.o c l a i m 4 , wherein
a shape of a punch s h o u l d e r p o r t i o n of t h e
t h i c k e n i n g i n n e r punch is e q u a l t o a shape of t h e
rounded punch s h o u l d e r p o r t i o n i n t h e f i r s t s t e p .