U.S. patent application number 16/603750 was filed with the patent office on 2020-04-16 for electromagnetic forming device.
The applicant listed for this patent is MITSUBISHI HEAVY INDUSTRIES, LTD.. Invention is credited to Takahiro TACHIBANA, Takayuki TAKAHASHI.
Application Number | 20200114411 16/603750 |
Document ID | / |
Family ID | 66173934 |
Filed Date | 2020-04-16 |
United States Patent
Application |
20200114411 |
Kind Code |
A1 |
TACHIBANA; Takahiro ; et
al. |
April 16, 2020 |
ELECTROMAGNETIC FORMING DEVICE
Abstract
The present invention is to enable accurate formation of an
elongate member while suppressing the occurrence of a shape defect.
An electromagnetic forming device is provided with an
electromagnetic coil, and a forming mold which is disposed along
the electromagnetic coil and provides an elongate material to be
formed with a formed shape. An electromagnetic force generated by
means of the electromagnetic coil is caused to act on the material
to be formed and the material to be formed is pressed onto the
forming mold. In the electromagnetic forming device, the forming
mold has a cross sectional shape that varies from one end to
another in a longitudinal direction of the material to be formed.
The forming mold is formed such that, as the material to be formed
is moved parallel to the longitudinal direction, the shape of the
material to be formed is gradually changed to a desired shape.
Inventors: |
TACHIBANA; Takahiro; (Tokyo,
JP) ; TAKAHASHI; Takayuki; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI HEAVY INDUSTRIES, LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
66173934 |
Appl. No.: |
16/603750 |
Filed: |
May 16, 2018 |
PCT Filed: |
May 16, 2018 |
PCT NO: |
PCT/JP2018/018914 |
371 Date: |
October 8, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B21D 53/92 20130101;
B21D 26/14 20130101 |
International
Class: |
B21D 26/14 20060101
B21D026/14; B21D 53/92 20060101 B21D053/92 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2017 |
JP |
2017-203890 |
Claims
1. An electromagnetic forming device comprising: an electromagnetic
coil; and a forming die installed along the electromagnetic coil so
as to provide a formed shape for a forming target material having
an elongated shape, wherein an electromagnetic force generated by
the electromagnetic coil is applied to the forming target material
so that the forming target material is pressed against the forming
die, wherein the forming die has a cross-sectional shape which
differs from one end side thereof toward the other end side thereof
along a longitudinal direction of the forming target material, and
wherein in the forming die, the forming target material moves
parallel to the longitudinal direction so that the forming target
material is formed to be gradually changed into a desired
shape.
2. The electromagnetic forming device according to claim 1, wherein
the electromagnetic coil is continuously formed along the forming
die.
3. The electromagnetic forming device according to claim 1, wherein
a plurality of the electromagnetic coils are installed, and wherein
the plurality of electromagnetic coils are respectively shorter
than the forming target material, and are installed along the
longitudinal direction of the forming target material.
4. The electromagnetic forming device according to claim 1, wherein
a plurality of the forming dies are installed, and wherein the
plurality of forming dies are respectively shorter than the forming
target material, and are installed along the longitudinal direction
of the forming target material.
5. The electromagnetic forming device according to claim 4, wherein
the plurality of forming dies have an inclined surface formed in an
end portion.
6. The electromagnetic forming device according to claim 4, wherein
the plurality of forming dies are formed to give the forming target
material a recessed shape or a projecting shape in the longitudinal
direction.
Description
TECHNICAL FIELD
[0001] The present invention relates to an electromagnetic forming
device.
BACKGROUND ART
[0002] For example, aircraft components such as a fuselage and a
main wing of an aircraft are configured so that structural members
such as plate-shaped skins, elongated frames, and stringers are
combined with each other. The elongated structural member
(elongated member) is a mold material, and has a cross-sectional
shape whose cross section has a Z-shape, for example. As
illustrated in FIG. 16B, the elongated member includes those which
have a plurality of steps (joggles) in which a plate thickness is
changed at each site along a longitudinal direction. An elongated
member 60 illustrated in FIG. 16B has a thick plate portion 61 and
a thin plate portion 62.
[0003] In a case of manufacturing the elongated member having a
cross-sectional shape bent in the Z-shape, as illustrated in FIG.
16A, roll forming is performed on an elongated material 50 having a
flat plate shape which is not bent. In a roll forming device which
performs the roll forming, multiple sets of two rolls interposing
the elongated member therebetween are installed along a line.
[0004] The elongated material is caused to sequentially pass from
one end side to the other end side of the line in which the
multiple sets of rolls are installed. In this manner, the elongated
material is gradually formed from a cross-sectional shape having
the flat plate shape to a cross-sectional shape required as a
product. In this way, the elongated material is gradually formed
using the multiple sets of rolls. Accordingly, it is possible to
prevent defect occurrence such as cracks caused by a rapid change
in the cross-sectional shape.
CITATION LIST
Patent Literature
[0005] [PTL 1] Japanese Unexamined Patent Application Publication
No. 2007-296553
[0006] [PTL 2] Japanese Unexamined Patent Application Publication
No. 6-23442
SUMMARY OF INVENTION
Technical Problem
[0007] However, in a case where the elongated material is formed by
performing the above-described roll forming, distortion and
residual stress occur in the formed elongated member due to wear of
a roll or a subtle change in a pressure mechanism which applies
pressure to the roll. Consequently, shape defects such as twisting,
warping (horizontal warping or vertical warping), and waving occur.
In addition, depending on a degree of the wear or the change in the
applied pressure, the distortion or the residual stress occurring
in each material may differ, thereby causing a possibility that the
shape may be changed in various ways including the twisting, the
warping, or the waving.
[0008] Furthermore, in a case where the cross-sectional shape to be
obtained after forming is changed, the roll forming device needs to
replace the roll in accordance with the shape. In an initial stage
after the replacement, the above-described shape defect is likely
to occur. It is necessary to adjust the role or the pressure
mechanism.
[0009] Furthermore, in a case of the elongated member in which the
plurality of steps are formed in the longitudinal direction, a
pressing way of the roll differs between the thick plate portion
and the thin plate portion. Therefore, in some cases, a bending
angle may not be a predetermined angle in each site. In addition,
in the roll forming, the elongated member passes through the two
rolls arranged up and down. Accordingly, as illustrated in FIG.
17A, one surface side is less likely to serve as a step surface,
and the other surface side is less likely to serve as a flat
surface. As illustrated in FIG. 17B, the step surface is also
formed on the other surface side. As a result, when the elongated
member having the plurality of steps are combined with the other
member so as to be assembled together as an aircraft component, a
gap is generated between the elongated member and the other
member.
[0010] On the other hand, a technology is known in which a forming
target material is formed using an electromagnetic forming device
instead of the roll forming device. However, no technology is known
in which forming an elongated material is formed so as to have a
cross-sectional shape bent in the Z-shape or the forming is
performed on the elongated member having the plurality of steps.
PTL 1 described above discloses a technology in which a thin plate
is formed into a desired shape by using the electromagnetic forming
device. PTL 2 discloses a technology in which an electromagnetic
force is applied in a multistage manner to a predetermined portion
of a hollow material by using an electromagnetic plastic processing
method.
[0011] The present invention is made in view of the above-described
circumstances, and an object thereof is to provide an
electromagnetic forming device which can perform highly accurate
forming by preventing a shape defect in forming an elongated
member.
Solution to Problem
[0012] According to an aspect of the present invention, there is
provided an electromagnetic forming device including an
electromagnetic coil, and a forming die installed along the
electromagnetic coil so as to provide a formed shape for a forming
target material having an elongated shape. An electromagnetic force
generated by the electromagnetic coil is applied to the forming
target material so that the forming target material is pressed
against the forming die. The forming die has a cross-sectional
shape which differs from one end side thereof toward the other end
side thereof along a longitudinal direction of the forming target
material. In the forming die, the forming target material moves
parallel to the longitudinal direction so that the forming target
material is gradually formed and changed to have a desired
shape.
[0013] According to this configuration, the electromagnetic force
generated by performing the electromagnetic coil is applied to the
forming target material having the elongated shape, and the forming
die provides the formed shape for the forming target material. The
forming die has the cross-sectional shape which differs from one
end side to the other end side along the longitudinal direction of
the forming target material. The forming target material moves
parallel to the longitudinal direction so that the forming target
material is gradually formed and changed to have the desired shape.
In this manner, the forming target material is moved parallel to
the longitudinal direction so that the electromagnetic force is
repeatedly applied to the forming target material. Accordingly, the
forming target material deformed by being pressed against the
forming die is gradually changed to have the desired shape.
[0014] In the above-described aspect, the electromagnetic coil may
be continuously formed along the forming die.
[0015] In the above-described aspect, the electromagnetic coils may
be respectively installed at a plurality of locations. The
plurality of electromagnetic coils may be respectively shorter than
the forming target material, and may be installed along the
longitudinal direction of the forming target material.
[0016] In the above-described aspect, a plurality of the forming
dies may be installed. The plurality of forming dies may be
respectively shorter than the forming target material, and may be
installed along the longitudinal direction of the forming target
material.
[0017] In the above-described aspect, the plurality of forming dies
may have an inclined surface formed in an end portion.
[0018] In the above-described aspect, the plurality of forming dies
may be formed so that the forming target material is provided with
a recessed shape or a projecting shape in the longitudinal
direction.
Advantageous Effects of Invention
[0019] According to the present invention, highly accurate forming
can be performed by preventing a shape defect in forming an
elongated member.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 is a schematic configuration diagram illustrating an
electromagnetic forming device according to a first embodiment of
the present invention.
[0021] FIG. 2 is a schematic configuration illustrating a
modification example of an electromagnetic coil of the
electromagnetic forming device according to the first embodiment of
the present invention.
[0022] FIG. 3 is a perspective view illustrating a forming die of
the electromagnetic forming device according to the first
embodiment of the present invention.
[0023] FIG. 4 is a plan view illustrating the forming die of the
electromagnetic forming device according to the first embodiment of
the present invention.
[0024] FIG. 5 is a front view illustrating the forming die of the
electromagnetic forming device according to the first embodiment of
the present invention.
[0025] FIG. 6 is a front view illustrating the forming die of the
electromagnetic forming device according to the first embodiment of
the present invention.
[0026] FIG. 7 is a front view illustrating the forming die of the
electromagnetic forming device according to the first embodiment of
the present invention.
[0027] FIG. 8 is a plan view illustrating the forming die of the
electromagnetic forming device according to the first embodiment of
the present invention.
[0028] FIG. 9 is a front view illustrating the forming die of the
electromagnetic forming device according to the first embodiment of
the present invention.
[0029] FIG. 10 is a longitudinal sectional view illustrating the
forming die of the electromagnetic forming device according to the
first embodiment of the present invention, and is a view taken
along arrow X-X in FIG. 6.
[0030] FIG. 11 is a longitudinal sectional view illustrating the
forming die of the electromagnetic forming device according to the
first embodiment of the present invention, and is a view taken
along arrow XI-XI in FIG. 8.
[0031] FIG. 12 is a longitudinal sectional view illustrating the
forming die of the electromagnetic forming device according to the
first embodiment of the present invention, and is a view taken
along arrow XII-XII in FIG. 8.
[0032] FIG. 13 is a perspective view illustrating a forming die of
an electromagnetic forming device according to a second embodiment
of the present invention.
[0033] FIG. 14 is a plan view illustrating the forming die of the
electromagnetic forming device according to the second embodiment
of the present invention.
[0034] FIG. 15 is a front view illustrating the forming die of the
electromagnetic forming device according to the second embodiment
of the present invention.
[0035] FIG. 16A is a perspective view illustrating an elongated
material.
[0036] FIG. 16B is a perspective view illustrating the elongated
material.
[0037] FIG. 17A is a perspective view and a partial side view
illustrating the elongated member.
[0038] FIG. 17B is a perspective view and a partial side view
illustrating the elongated member.
DESCRIPTION OF EMBODIMENTS
[0039] Hereinafter, embodiments according to the present invention
will be described with reference to the drawings.
First Embodiment
[0040] Hereinafter, a first embodiment according to the present
invention will be described with reference to FIGS. 1 to 12. As
illustrated in FIG. 16A, an electromagnetic forming device 1
according to the present embodiment uses a forming die 4 so as to
provide a cross-sectional shape, for example, a Z-shape, for an
elongated material 50 serving as a forming target material made of
an aluminum alloy, for example. As illustrated in FIG. 16B, an
elongated member 60 formed by performing the electromagnetic
forming device 1 is used as a structural member such as a frame and
a stringer which configure aircraft components such as a fuselage
and a main wing of an aircraft.
[0041] As illustrated in FIG. 1, the electromagnetic forming device
1 according to the present embodiment has an electromagnetic coil
2, a power supply unit 3 for supplying an electric current to the
electromagnetic coil 2, and the forming die 4.
[0042] The electromagnetic coil 2 is continuously formed along the
forming die 4. For example, as illustrated in FIG. 1, the
electromagnetic coil 2 may have a cylindrical shape, and a
cross-sectional shape thereof may be circular. As illustrated in
FIG. 2, the electromagnetic coil 2 may be located along a surface
of the forming die 4.
[0043] A large current is supplied to the electromagnetic coil 2
from the power supply unit 3. A power supply circuit 5 is
configured to include a circuit as follows. For example, as
illustrated in FIG. 1, a capacitor 6 is installed in parallel with
the electromagnetic coil 2. A switch 7 is installed between a
connection point of the power supply unit 3 and the capacitor 6 and
the electromagnetic coil 2. In this configuration, when the switch
7 is turned on, the capacitor 6 is electrically charged from the
power supply unit 3 via an electric resistance 8. Then, the switch
7 is turned off, and the capacitor 6 is electrically discharged,
thereby generating the large current to the electromagnetic coil
2.
[0044] The large current is instantaneously applied to the
electromagnetic coil 2, thereby generating an induced current on a
surface of the elongated material 50 located along the
electromagnetic coil 2. As a result, an electromagnetic force is
applied to the surface of the elongated material 50, and the
elongated material 50 moves in a direction of the forming die 4 so
as to be pressed against the forming die 4.
[0045] The forming die 4 is installed along the longitudinal
direction of the elongated material serving as the forming target
material. The forming die 4 provides the formed shape for the
elongated material. In order to prevent defect occurrence such as
cracks caused by a rapid change in the cross-sectional shape, as
illustrated in FIGS. 3 to 5, the forming die 4 has a
cross-sectional shape which differs from one end 4a side toward the
other end 4b side along the longitudinal direction of the elongated
material 50. That is, as illustrated in FIGS. 4 to 9, the elongated
material 50 moves parallel to the longitudinal direction. In this
manner, the elongated material 50 is formed so as to be gradually
changed to the desired shape.
[0046] For example, the electromagnetic coil 2 and the forming die
4 have substantially the same length as the elongated material 50.
Without being limited to a case where only one electromagnetic coil
2 is continuously formed in the longitudinal direction, the
electromagnetic coil 2 may be divided into a plurality of pieces in
the longitudinal direction. In this case, the plurality of
electromagnetic coils 2 are disposed to be separate from each
another.
[0047] A forming method of the formed elongated member 60 (refer to
FIG. 16B) will be described with reference to FIGS. 3 and 10 to 12.
The elongated member 60 has horizontal flange portions 63 and 64,
and a web portion 65 which forms an angle of 90.degree. with the
flange portions 63 and 64. As illustrated in FIG. 3, a forming
surface 9a on one end 4a side in the forming die 4 has a horizontal
flat surface shape. Then, a forming surface 9b for forming the web
portion 65 on the forming surface 9 of the forming die 4 has the
same width from one end 4a side to the other end 4b side, and an
inclination angle thereof is constant while a horizontal state is
maintained. Forming surfaces 9c and 9d for forming the flange
portions 63 and 64 have the same width from one end 4a side to the
other end 4b side, and an inclination angle thereof is gradually
inclined from the horizontal state to a vertical state.
[0048] In an electromagnetic forming method using the
electromagnetic forming device 1 according to the present
embodiment, first, as illustrated in FIGS. 4 and 5, only one end
50a side of the flat plate-shaped elongated material 50 is one end
4a of the forming die 4 is installed on one end 4a side of the
forming die 4. Then, the current is supplied to the electromagnetic
coil 2, and the elongated material 50 is pressed against the
forming die 4. As a result, as illustrated in FIGS. 4 and 5, one
end 50a of the elongated material 50 is formed along the forming
die 4.
[0049] Thereafter, as illustrated in FIGS. 6 and 7, the elongated
material 50 is shifted to the other end side as much as a
predetermined distance along the longitudinal direction. Then, the
current is supplied to the electromagnetic coil 2, and the
elongated material 50 is pressed against the forming die 4. As a
result, the elongated material 50 is shifted in the longitudinal
direction. In this manner, the flat plate-shaped elongated material
50 falling within a range of the electromagnetic coil 2, and one
end 50a side of the elongated material 50 previously formed along
the forming die 4 are formed along the forming die 4.
[0050] The above-described procedure is repeatedly performed,
thereby causing the elongated material 50 to gradually deform into
a final shape from the one end 50a side to the other end 50b side.
The elongated material 50 passing through the other end 4b side of
the forming die 4 has the final shape obtained by performing the
electromagnetic forming. Until the other end 50b of the elongated
material 50 completely passes therethrough, the forming is
repeatedly performed by shifting the position of the elongated
material 50 and supplying the current to the electromagnetic coil
2. If the other end 50b of the elongated material 50 completely
passes therethrough, the elongated member 60 has the final shape
obtained by performing the electromagnetic forming over the entire
longitudinal direction of the elongated material 50 (refer to FIG.
16B).
[0051] As described above, according to the electromagnetic forming
using the electromagnetic forming device 1 of the present
embodiment, a mold is less worn compared to the roll forming, and a
compression mechanism such as the roll forming device is not
provided. Accordingly, during the forming, there is no subtle
change in the compression mechanism. Therefore, the shape defect is
less likely to occur in the elongated member 60 formed by
performing the electromagnetic forming. In addition, the forming
die 4 has a continuous shape in the longitudinal direction.
Accordingly, a setup time for roll clearance adjustment in the roll
forming device can be reduced.
[0052] Furthermore, the forming is performed at high speed by
utilizing the electromagnetic force. Accordingly, a spring-back
volume can be reduced, the forming can be highly accurately
performed, and work for correcting distortion after the forming can
be reduced.
Second Embodiment
[0053] Next, a second embodiment according to the present invention
will be described with reference to FIGS. 13 to 15. In the
above-described first embodiment, a case of using the forming die 4
having the continuous shape in the longitudinal direction has been
described. However, the present invention is not limited to this
example.
[0054] The forming die 4 according to the second embodiment of the
present invention is divided into a plurality of pieces in the
longitudinal direction, and split molds 10A, 10B, and 10C are
arranged to be separate from each other. In this manner, cost can
be reduced, compared to a case of using the forming die 4 having
the continuous shape in the longitudinal direction.
[0055] The electromagnetic coil 2 is divided into each position
corresponding to the respective split molds 10A, 10B, and 10C, and
the respective split molds 10A, 10B, and 10C are installed to be
separate from each other. The forming die 4 and the electromagnetic
coil 2 are divided into three in an example illustrated in FIG. 13,
but may be divided into two, and four or more.
[0056] A forming surface 11 of the split molds 10A, 10B, and 10C
has a forming surface 11a for forming the web portion 65, a forming
surface 11b for forming the flange portion 63, and a forming
surface 11c for forming the flange portion 64. In the respective
split molds 10A, 10B, and 10C, the forming surfaces 11a, 11b, and
11c have the same width from one end side to the other end side.
The present invention is not limited to this example. As in the
first embodiment, the forming surfaces 11b and 11c may be gradually
inclined from one end side to the other end side, and the
inclination angle may be gradually inclined from the horizontal
side to the vertical side.
[0057] An end portion of the forming surface 11a for forming the
web portion 65 in the respective split molds 10A, 10B, and 10C may
have a tapered surface 11d inclined toward the adjacent split molds
10A, 10B, and 10C. In this manner, the elongated material 50 can be
smoothly moved without the elongated material 50 being caught
thereon.
[0058] According to the present embodiment, as in the first
embodiment, the following procedure is also repeated performed. The
current is supplied to the electromagnetic coil 2 so that the
elongated material 50 is pressed against the forming die 4.
Thereafter, the elongated material 50 is shifted to the other end
side as much as the predetermined distance along the longitudinal
direction. FIGS. 14 and 15 illustrate an example of a positional
relationship between the elongated material 50 and the split molds
10A, 10B, and 10C during the forming.
[0059] Then, the elongated material 50 is caused to gradually
deform into the final shape from the one end 50a side to the other
end 50b side.
[0060] The elongated material 50 formed according to the present
embodiment may have a uniform thickness in the longitudinal
direction. Alternatively, as illustrated in FIG. 16A, the elongated
material 50 may have a plurality of steps (joggles) in which the
plate thickness is changed at each site along the longitudinal
direction. In this case, when the elongated material 50 is formed
by performing the electromagnetic forming, the forming surfaces
11a, 11b, and 11c of the respective split molds 10A, 10B, and 10C
may have a recessed shape or a projecting shape corresponding to
each shape of the plurality of steps so that the plurality of steps
are formed in the longitudinal direction. In this manner, the
electromagnetic forming device 1 not only provides the
cross-sectional shape of the Z-shape, but also simultaneously forms
the plurality of steps in the longitudinal direction. Therefore,
the forming process can be reduced, and the cost can be
reduced.
[0061] In a case of the present embodiment, compared to the first
embodiment adopting the forming die 4 having the continuous shape
in the longitudinal direction, the cost for manufacturing the
forming die 4 can be reduced. In addition, as in the first
embodiment, the mold is less worn compared to the roll forming, and
the compression mechanism such as the roll forming device is not
provided. Accordingly, during the forming, there is no subtle
change in the compression mechanism. Therefore, the shape defect is
less likely to occur in the elongated member 60 formed by
performing the electromagnetic forming. In addition, the forming is
performed at high speed by utilizing the electromagnetic force.
Accordingly, a spring-back volume can be reduced, the forming can
be highly accurately performed, and work for correcting distortion
after the forming can be reduced.
REFERENCE SIGNS LIST
[0062] 1: electromagnetic forming device
[0063] 2: electromagnetic coil
[0064] 3: power supply unit
[0065] 4: forming die
[0066] 5: power supply circuit
[0067] 6: capacitor
[0068] 7: switch
[0069] 8: electric resistance
[0070] 9: forming surface
[0071] 9a, 9b, 9c, 9d: forming surface
[0072] 10A, 10B, 10C: split mold
[0073] 11: forming surface
[0074] 11a, 11b, 11c: forming surface
[0075] 11d: tapered surface
[0076] 50, 60: elongated material
[0077] 61: thick plate portion
[0078] 62: thin plate portion
[0079] 63, 64: flange portion
[0080] 65: web portion
* * * * *