TECHNICAL FIELD
[0001] The present invention relates to a method for
shaping a bossed cylindrical container that is
suitable for being used to.shape a bottomed
cylindrical container into a bossed cylindrical
container having a boss portion in a bottom portion.
BACKGROUND ART
[ 0002] A method of Patent Literature 1 is publicly
known hitherto as a method for shaping a cylindrical
container having a boss portion in a bottom portion.
Describing the technique of Patent Literature 1
with' reference to Fig. 7, a drawing method
shaping a bottomed cylindrical body includ
fixed die 1 having an annular shoulder por
die hole formed in an inner peripheral sur
annular shoulder portion and a movable pun
capable of moving forward and backward rel
the die hole, and moving the movable punch
and pushing it into the die hole of the fi
In this method, a movable die 4 , whose own
is in contact with a surface of a workpiec
shaping or in middle of shaping, is moved
to forward movement of the movable punch 2
performing the shaping while actively supp
shaping facilitating direction the materia
workpiece in contact with the die surface.
~ 1 -
for
es using a
tion and a
face of the
ch 2
a t i v e bo
2 forward
xed die 1.
die face
e 3 before
according
, thereby
lying in a
1 of the
[0003]- Further, Patent Literature 2 discloses a
technique to form a boss portion by using a holding
punch and a counter punch opposing it and by pushing
an opening end surface of a cup-shaped member with a
ring punch.
CITATION LIST
PATENT LITERATURE
[000 4] Patent Literature 1: Japanese Laid-open
Patent Publication No. 2002-113528
Patent Literature 2: Japanese Laid-open Patent
Publication No. 9-150223
SUMMARY OF INVENTION
TECHNICAL PROBLEM
[000 5] The methods of Patent Literatures 1, 2 are
effective for shaping a boss portion, but require a
multi-spindle double action press.
[0006] The present invention has been made to solve
the above-described conventional drawback, and an
object thereof is to allow easily manufacturing a
bossed cylindrical container having a boss portion in
a bottom portion by using a typical single-spindle
press.
SOLUTION TO PROBLEM
[0007] The gist of the present invention for solving
the above-described problem is as follows.
[1] A method for shaping a bossed cylindrical
container by which a bottomed cylindrical container
having a container bottom portion and a container
sidewall portion continuing to the container bottom
- 2 -
portion via a container curved surface portion is
shaped into a bossed cylindrical container having a
boss portion in a bottom portion, the method
including:
a first step of using a boss shaping die and a
boss shaping punch with a center axis disposed
coaxially with the boss shaping die;
a second step of using a reduction die and a
reduction punch with a center axis disposed coaxially
with the reduction die; and
a third step of using an ironing die and an
ironing punch with a center axis disposed coaxially
with the ironing die,
wherein all of the boss shaping die, the
reduction die and the ironing die have a die hole
including: a first sidewall portion extending in a
first direction along the center axis; a die inclined
portion continuing to the first sidewall portion via
a first curved surface portion and gradually widening
in a direction orthogonal to the center axis as
advancing in the first direction; and a second
sidewall portion continuing to the die inclined
portion via a second curved surface portion and
extending in the first direction,
wherein the boss shaping punch has a stepped
trench portion formed in an outer edge part in a
direction orthogonal to the center axis,
wherein the reduction punch has a punch inclined
portion,
- 3 -
wherein the ironing punch is in a columnar shape
having a smaller outside diameter than an inside
diameter of the first sidewall portion,
wherein in the first step, taking the bottomed
cylindrical container as a workpiece, in a state that
a side of the container bottom portion of the
bottomed cylindrical container is supported by the
die inclined portion, and that a container opening
end of the bottomed cylindrical container is bound by
the stepped trench portion and the second sidewall
portion, the boss shaping punch is relatively moved
so as to insert the boss shaping punch into the die
hole, thereby pushing part of the bottomed
cylindrical container into a die hole deep portion
surrounded by the first sidewall portion in the die
hole, so as to shape the bottomed cylindrical
container into a bossed cylindrical container having
a boss portion inside the die hole deep portion, a
container inclined portion along the die inclined
portion, and the container sidewall portion along the
second sidewall portion, and
wherein in the second step, taking the bossed
cylindrical container shaped in the first step as a
workpiece, the reduction punch is relatively moved so
as to insert the reduction punch into the die hole,
thereby pressing with the punch inclined portion and
the die inclined portion the container inclined
portion increased in thickness by influx of a
material of the container sidewall portion in the
- 4 -
first step, so as to make an excess material of the
cont.ainer inclined portion flow into a sidewall
portion of the boss portion, and
wherein in the third step, taking the bossed
cylindrical container shaped in the second step as a
workpiece, the ironing punch is relatively moved so
as to insert the ironing punch into the die hole deep
portion, thereby ironing the sidewall portion of the
boss portion into which the excess material of the
container inclined portion is made to flow in the
second step.
[2 ] The method for shaping the bossed cylindrical
container according to [1], wherein in the second
step, the container opening end is a free end.
'[3] The method for shaping the bossed cylindrical
container according to [1], wherein a common die is
used as the boss shaping die, the reduction die and
the ironing die.
ADVANTAGEOUS EFFECTS OF INVENTION
[0008] According to the present invention, a bossed
cylindrical container having a boss portion in a
bottom portion can be produced easily by using a
typical single-spindle press.
BRIEF DESCRIPTION OF DRAWINGS
[0009] [Fig. 1] Fig. 1 is a cross-sectional view
illustrating a state before shaping a boss of a
workpiece in a first step.
[Fig. 2] Fig. 2 is a cross'-sectional view
illustrating a state after shaping the boss of the
_ 5 _
workpiece in the first step.
[Fig. 3] Fig. 3 is a cross-sectional view
illustrating a state before reducing an inclined
portion of a workpiece in a second step.
[Fig. 4] Fig. 4 is a cross-sectional view
illustrating a state after reducing the inclined
portion of the workpiece in the second step.
[Fig. 5] Fig. 5 is a cross-sectional view
illustrating a state before ironing a boss portion of
a workpiece in a third step.
[Fig. 6] Fig. 6 is a cross-sectional view
illustrating a state after ironing the boss portion
of the workpiece in the third step.
[Fig. 7] Fig. 7 is a cross-sectional view
illustrating a conventional boss shaping process.
DESCRIPTION OF EMBODIMENTS
[0010] Hereinafter, embodiments of the present
invention will be described with reference to the
attached drawings.
The method for shaping a bossed cylindrical
container according to this embodiment is to shape a
bottomed cylindrical container into a bossed
cylindrical container having a boss portion in a
bottom portion, and has a first step of using a boss
shaping die 30 and a boss shaping punch 20, a second
step of using a reduction die 7 0 and a reducing punch
60, and a third step of using an ironing die 100 and
an ironing punch 90.
Here, "having a boss portion in a bottom portion"
_ 6 _
means that the bottom portion of the cylindrical
container is made to project in a cylindrical
bottomed projecting shape.
[0011] Hereinafter, details of the steps will be
described.
(First Step)
Cross-sectional views of Fig. 1 and Fig. 2
illustrate a state before shaping and a state after
shaping in the first step. With reference to these
views, a press machine has the boss shaping punch 2 0,
the boss shaping die 30, and a knockout 40 whose
respective center axes C are arranged coaxially, and
the boss shaping die 30 and the knockout 40 are
disposed to oppose the boss shaping punch 20.
A bottomed cylindrical container 10 which will be
a workpiece in this embodiment is press-formed and
has a container bottom portion 11 and a container
sidewall portion 12 continuing to the container
bottom portion 11 via a container curved surface
portion 13.
[0012] The boss shaping die 30 is a fixed type
having a die hole 3 6 including a first sidewall
portion 31 extending upward (first direction) in Fig.
1 along a center axis C, a first curved surface
portion 32, a die inclined portion 33 continuing to
the first sidewall portion 31 via the first curved
surface portion 32 and gradually widening in a radial
direction orthogonal to the center axis as advancing
in the first direction, a second curved surface
- 7
portion 34, and a second sidewall portion 35
continuing to the die inclined portion 3 3 via the
second curved surface portion 34 and extending in the
first direction. In the die hole 36, a portion
surrounded by the first sidewall portion 31 is a die
hole deep portion 37. An inside diameter of the
second sidewall portion 35 of the boss shaping die 3 0
is substantially equal to an outside diameter of the
container sidewall portion 12 of the bottomed
cylindrical container 10.
The knockout 40 has a columnar shape and is for
removing a shaped product from the die, and is
movable and capable of being lifted and lowered by a
mechanical driving source. The knockout 40 is
disposed in a deep side in the die hole deep portion
37 .
[0013] The boss shaping punch 20 has a first flat
portion 21 in parallel with a radial direction
orthogonal to the center axis C, a curved surface
portion 22, a first sidewall portion 2 3 continuing to
the first flat portion 21 via the curved surface
portion 22 and extending in a first direction, a
second flat portion 24 continuing to the first
sidewall portion 2 3 and in parallel with the radial
direction orthogonal to the center axis C, a second
sidewall portion 2 5 continuing to the second flat
portion 24 and extending in the first direction, and
is movable and capable of being lifted and lowered by
a not-illustrated mechanical driving source
(hydraulic, by servomotor, or the like}. A stepped
trench portion 2 6 is formed including the first
sidewall portion 23 and the second flat portion 24.
The stepped trench portion 2 6 is formed in an outer
edge portion in a radial direction orthogonal to the
center axis C in the boss shaping punch 20. An
outside diameter of the first sidewall portion 2 3 of
the boss shaping punch 2 0 is substantially equal to
an inside diameter of the container sidewall portion
12 of the bottomed cylindrical container 10.
[ 0014] The bottomed cylindrical container
(workpiece) 10 is placed in the boss shaping die 30
so that the container bottom portion 11 side is
supported by the die inclined portion 33, and the
boss shaping punch 20 is moved downward {so as to
insert the boss shaping punch 2 0 into the die hole
36). Thus, a container opening end 14 of the
container sidewall portion 12 of the workpiece 10 is
pushed downward with the second flat portion 24 of.
the boss shaping punch 20, and part of the workpiece
10 is pushed into the die hole.deep portion 37, so as
to shape the bottomed cylindrical container 10 into a
bossed cylindrical container 5 0 having a boss portion
51 inside the die hole deep portion 37, a container
inclined portion 52 along the die inclined portion 3 3
and a container sidewall portion 5 3 along the second
sidewall portion 3 5 as illustrated in Fig. 2.
After the shaping, the knockout 4 0 is raised to
take out the bossed cylindrical container 50 from the
9
boss shaping die 30.
[0015] In the first step, as illustrated in Fig. 1,
the shaping is performed in.a state that the vicinity
of the container opening end 14 of the container
sidewall portion 12 of the workpiece 10 is bound by
the second flat portion 2 4 and the first sidewall
portion 35 (stepped trench portion 26) of the boss
shaping punch 2 0 and the second sidewall portion 35
of the boss shaping die 30. Thus, the shaping is
possible without buckling of the container sidewall
portion 12.
Further, the container sidewall portion 12 of the
workpiece 10 is pushed in the direction of the die
inclined portion 3 3 of the boss shaping die 30, and
as illustrated in Fig. 2, when the container inclined
portion 52 is shaped, the workpiece 10 is shaped in a
state of being in contact with and bound by the die
inclined portion 3 3 of the boss shaping die 30, and
thus the container inclined portion 52 can be shaped
without buckling. At this moment, the container
inclined portion 52 increases in thickness by influx
of the material of the container sidewall portion 53.
[0016] (Second Step)
Cross-sectional views of Fig. 3 and Fig. 4
illustrate a state before shaping and a state after
shaping in the second step. With reference to these
views, the press machine has the reduction punch 60,
the reduction die 70, and a knockout 80 whose
respective center axes C are arranged coaxially, and
- 10 -
the reduction die 7 0 and the knockout 8 0 are disposed
to oppose the reduction punch 60.
[0017] The reduction die 7 0 has a structure similar
to the boss shaping die 30, and is a fixed type
having a die hole 7 6 including a first sidewall
portion 71 extending upward (first direction) in Fig.
3 along the center axis C, a first curved surface
portion 72, a die inclined portion 7 3 continuing to
the first sidewall portion 71 via the first curved
surface portion 72 and gradually widening in a radial
direction orthogonal to the center axis as advancing
in the first direction, a second curved surface
portion 74, and a second sidewall portion 75
continuing to the die inclined portion 7 3 via the
second curved surface portion 74 and extending in the
first direction. In the die hole 76, a portion
surrounded by the first sidewall portion 71 is a die
hole deep portion 77. An inside diameter of the
second sidewall portion 75 of the boss shaping die 70
is substantially equal to an outside diameter of the
container sidewall portion 5 3 of the bossed
cylindrical container 50.
The knockout 80 has a columnar shape and is for
removing a shaped product from the die, and is
movable and capable of being lifted and lowered by a
mechanical driving source. The knockout 8 0 is
disposed in a deep side in the die hole deep portion
77 .
[0018] The reduction punch 60 has a first flat
- 11 -
portion 61 in parallel with a radial direction
orthogonal to the center axis C, a first curved
surface portion 62, a punch, inclined portion 63
continuing to the first flat portion 61 via the first
curved surface portion 62 and gradually widening in
the radial direction as advancing in the first
direction,, a second curved portion 64, a sidewall
portion 65 continuing to the punch inclined portion
63 via the,second curved portion 64 and extending in
the first direction, and is movable and capable of
being lifted and lowered by a non-illustrated
mechanical driving source. An outside diameter of
the sidewall portion 65 of the reduction punch 60 is
substantially equal to an inside diameter of the
container sidewall portion 5 3 of the bossed
cylindrical container 50 shaped in the first step.
Here, the inclination angles of the die inclined
portion 73 and the punch inclined portion 63 may be
either equal or different.
[0019] The bossed cylindrical container (workpiece)
50 shaped in the first step is placed in the
reduction die 70, and the reduction punch 60 is moved
downward (so as to insert the reduction punch 60 into
the die hole 76). Thus, the container inclined
portion 52 of the workpiece 50 increased in thickness
in the fir-st step is pressed by the punch inclined
portion 63 of the reduction punch 60 and the die
inclined portion 7 3 of the reduction die 70, so as to
make an excess material flow into a sidewall portion
- 12
54 of the boss portion 51. Thus, as illustrated in
Fig.. 4, the container inclined portion 52 with a
uniform thickness is obtained.
After the shaping, the knockout 8 0 is raised to
take out the bossed cylindrical container 50 from the
reduction die 70.
[0020] In the second step, since the container
inclined portion 52 of the workpiece 5 0 is pressed by
the punch inclined portion 63 of the reduction punch
60 and the die inclined portion 7 3 of the reduction
die 70, a uniform thickness can be ensured.
Further, when the container inclined portion 52
of the workpiece 5 0 is pressed by the punch inclined
portion 63 of the reduction punch 60 and the die
inclined portion 73 of the reduction die 70, a
container opening end 5 6 of the container sidewall
portion 53 and a bottom portion 55 of the boss
portion 51 of the workpiece 50 are in a free state
without being bound by the die, and thus excessive
increase in load by increase in hydrostatic stress
can be suppressed.
[0021] (Third Step)
Cross-sectional views of Fig. 5 and Fig. 6
illustrate a state before shaping and a state after
shaping in the third step. With reference to these
views, the press machine has the ironing punch 90,
ironing die 100, and a knockout 110 whose respective
center axes C are arranged coaxially, and the ironing
die 100 and the knockout 110 are disposed to oppose
- 13 -
the ironing punch 90.
[0022] The ironing die 100 has a structure similar
to the boss shaping die 30 and the reduction die 70,
and is a fixed type having a die hole 106 including a
first sidewall portion 101 extending upward (first
direction) in Fig. 5 along the center axis C, a first
curved surface portion 102, a die inclined portion
103 continuing to the first sidewall portion 101 via
the first curved surface portion 102 and gradually
widening in a radial direction orthogonal to the
center axis as advancing in the first direction, a
second curved surface portion 104, and a second
sidewall portion 105 continuing to the die inclined
portion 10 3 via the second curved surface portion 10 4
and extending in the first direction. In the die
hole 106, a portion surrounded by the first sidewall
portion 101 is a die hole deep portion 107.
The knockout 110 has a columnar shape and is for
removing the shaped product from the die, and is
movable and capable of being lifted and lowered by a
mechanical driving source. The knockout 110 is
disposed in a deep side in the die hole deep portion
107.
[0023] The ironing punch 90 has a flat portion 91 in
parallel with a radial direction orthogonal to the
center axis C, a curved surface portion 92, and a
sidewall portion 9 3 continuing to the flat portion 91
via the curved surface portion 9 2 and extending in
the first direction, and is movable and capable of
14
being -lifted and lowered by a non-illustrated
mechanical driving source. The ironing punch 90 is
columnar and has an outside diameter smaller than an
inside diameter of the first sidewall portion 101 of
t h e i r o n i n g d i e l O O.
[0024] The bossed cylindrical container (workpiece)
5 0 shaped in the second step is placed in the ironing
die 100, and the ironing punch 90 is moved downward
(so as to insert the ironing punch 90 into the die
hole deep portion 107). Thus, the sidewall portion
54 of the workpiece 50 is pressed and ironed by the
curved surface portion 92 and the sidewall portion 9 3
of the ironing punch 90 and the first sidewall
portion 101 and the curved surface portion 102 of the
ironing die 100. Thus, as illustrated in Fig. 6, the
boss portion 51 with a uniform thickness is obtained.
After the shaping, the knockout 110 is raised to
take out the bossed cylindrical container 5 0 from the
ironing die 100.
[002 5] As described above, the bossed cylindrical
container having a boss portion in a bottom portion
can be produced easily by using a typical singlespindle
press.
Note that as the material of the workpiece, one
of various publicly known types that can be formed
plastically can be employed, which include metals
such as steel, aluminum, and copper, or alloys or the
like of them.
Further, another step may further follow the
- 15
third step. For example, after the third step, using
a not-illustrated die, shaping to change the
inclination angle of the container inclined portion
52 of the bossed cylindrical container 50 (for
example, change it to an angle closer to horizontal)
or shaping to make the bottom portion 55 of the boss
portion 51 flat, and/or the like may be performed.
[0026] In the foregoing, the present invention has
been described together with various embodiments, but
the invention is not limited to these embodiments and
a modification and the like thereof can be made
within the range of the invention.
For example, in the above-described embodiments,
although the boss shaping die 30, the reduction die
70 and the ironing die 100 have been described as
separate dies, it may be changed to use a common die.
That is, through the first step to the third step,
the die is common and the boss shaping punch 20, the
reduction punch 60, and the ironing punch 90 may be
used selectively.
[0027] Further, the top and bottom of the tools can
be reversed. Specifically, the knockouts 40, 80, 110
and the dies 30, 70, 100 may be disposed on a top
side, and the punches 20, 60, 90 may be disposed on a
bottom side.
[0028] Further, the press machine may be configured
to move, in the first step, the boss shaping die 30
upward and relatively move the boss shaping punch 2 0
with respect to the boss shaping die 30 to insert
- 16 -
boss shaping punch 2 0 into the die hole 36, to
thereby push part of the bottomed cylindrical
container 10 into the die hole deep porta.on 37, so as
to shape the bottomed cylindrical container 10 into
the bossed cylindrical container 50.
Similarly, it may also be configured to move, in
the second step, the reduction die 7 0 upward and
relatively move the reduction punch 60 with respect
to the reduction die 7 0 to insert the reduction punch
60 into the die hole 36, to thereby press the
container inclined portion 52 with the punch inclined
portion 63 and the die inclined portion 73.
Similarly, it may also be configured to move, in
the third step, the ironing die 100 upward and
relatively move the ironing punch 9 0 with respect to
the ironing die 100 to insert the ironing punch 9 0
into the die hole deep portion 107, to thereby iron
the sidewall portion 54 of the boss portion 51.
INDUSTRIAL APPLICABILITY
[0029] The present invention is suitable for being
used to shape a bottomed cylindrical container into a
bossed cylindrical container having a boss portion in
a bottom portion.

CLAIMS
[Claim 1] A method for shaping a bossed cylindrical
container by which a bottomed cylindrical container
having a container bottom portion and a container
sidewall portion continuing to the container bottom
portion via a container curved surface portion is
shaped into a bossed cylindrical container having a
boss portion in a bottom portion, the method
comprising:
a first step of using a boss shaping die and a
boss shaping punch with a center axis disposed
coaxially with the boss shaping die;
a second step of using a reduction die and a
reduction punch with a center axis disposed coaxially
with the reduction die; and
a third step of using an ironing die and an
ironing punch with a center axis disposed coaxially
with the ironing die,
wherein all of the boss shaping die, the
reduction die and the ironing die have a die hole
including: a first sidewall portion extending in a
first direction along the center axis; a die inclined
portion continuing to the first sidewall portion via
a first curved surface portion and gradually widening
in a direction orthogonal to the center axis as
advancing in the first direction; and a second
sidewall portion continuing to the die inclined
portion via a second curved surface portion and
extending in the first direction,
- li
wherein the boss shaping punch has a stepped
trench portion formed in an outer edge part in a
direction orthogonal to the center axis,
wherein the reduction punch has a punch inclined
portion,
wherein the ironing punch is in a columnar shape
having a smaller outside diameter than an inside
diameter of the first sidewall portion,
wherein in the first step, taking the bottomed
cylindrical container as a workpiece, in a state that
a side of the container bottom portion of the
bottomed cylindrical container is supported by the
die inclined portion, and that a container opening
end of the bottomed cylindrical container is bound by
the stepped trench portion and the second sidewall
portion, the boss shaping punch is relatively moved
so as to insert the boss shaping punch into the die
hole, thereby pushing part of the bottomed
cylindrical container into a die hole deep portion.
surrounded by the first sidewall portion in the die
hole, so as to shape the bottomed cylindrical
container into a bossed cylindrical container having
a boss portion inside the die hole deep portion, a
container inclined portion along the die inclined
portion, and the container sidewall portion along the
second sidewall portion, and
wherein in the second step, taking the bossed
cylindrical container shaped in' the first step as a
workpiece, the reduction punch is relatively moved so
- 19 -
as to insert the reduction punch into the die hole,
thereby pressing with the punch inclined portion and
the die inclined portion the container inclined
portion increased in thickness by influx of a
material of the container sidewall portion in the
first step, so as to make an excess material of the
container inclined portion flow into a' sidewall
portion of the boss portion, and
wherein in the third step, taking the bossed
cylindrical container shaped in the second step, as a
workpiece, the ironing punch is relatively moved so
as to insert the ironing punch into the die hole deep
portion, thereby ironing the sidewall portion of the
boss' portion into which the excess material of the
container inclined portion is made to flow in the
second step. |
[Claim 2] The method for shaping the bossed
cylindrical container according to claim 1, wherein
in the second! step, the container opening end i L\ a
free end.
[Claim 3] The method for shaping the bossed
cylindrical container according to claim 1, wherein a
common die is used as the boss shaping die, the
reduction die and the ironing die.