JP2020168635A - Press forming shearing method - Google Patents

Abstract

An object of the present invention is to provide a press-formed processed material with excellent dimensional accuracy. A work piece having a first surface and a second surface is placed on the second surface side of the work piece, and a convex first die having a protruding central portion and a peripheral portion; A central portion and a protruding peripheral portion that are arranged on the first surface side of the material and are arranged between the concave punch arranged to face the first die, or are arranged on the first surface side of the workpiece and protrude. and a first concave die disposed on the second side of the workpiece and facing the peripheral portion of the punch; and a first die to press-form the workpiece to obtain a press-formed body, and while pressing the press-formed body with the punch and the first die, arranged around the punch and the first die A press-forming shearing method, comprising shearing a press-formed body with a second die to obtain a processed material. [Selection drawing] Fig. 3

Description

The present disclosure relates to a press forming shearing method.

When a metal plate is press-molded using a die in which a punch and a die are arranged to face each other, stress is generated in the press-molded body, and the molded product after mold release has springback and twist due to elastic recovery. Can occur.

Therefore, when the press-molded body is used as the final product, there is a problem of dimensional defects, and when the press-molded body is further molded or cut, the press-molded body is deformed and therefore inside the mold. There is a problem that the press-molded body cannot be accurately arranged at a predetermined position such as.

In recent years, in order to reduce the weight of automobile body structural members, the application of thin high-strength steel plates and aluminum alloy plates having a small specific gravity has been increasing. However, the above problem becomes more remarkable in high-strength steel plates and aluminum alloy plates.

Since springback occurs when the stress of the press-formed body is released, the smaller the stress of the press-formed body, the more the springback can be suppressed. Therefore, reducing the stress of the press-molded body has been a conventional issue, and some press-molding methods have been proposed in which deformation and dimensional defects are less likely to occur by setting the press-molding die to a predetermined configuration. (Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-051005

However, the dimensional accuracy of the press-formed body is still insufficient, and further improvement in dimensional accuracy is desired.

The present inventor has conducted diligent research on the above problems and found a press-molded shearing method in which shearing is performed together with press-forming.

The gist of this disclosure is as follows.
(1) A work material having a first surface and a second surface on the opposite side thereof.
A convex first die arranged on the second surface side of the work material and having a protruding central portion and a peripheral portion, and a convex first die arranged on the first surface side of the work material and having a protruding central portion and a peripheral portion. A convex punch arranged between the concave punches arranged so as to face the peripheral portion or having a central portion and a peripheral portion arranged on the first surface side of the material to be processed and having a protruding central portion and a peripheral portion, and the subject. Between the concave first die arranged on the second surface side of the work material and arranged so as to face the peripheral portion of the punch.
To place,
The work material is press-molded with the punch and the first die to obtain a press-molded body, and the punch and the punch while pressing the press-molded body with the punch and the first die. A press-molding shearing method comprising shearing the press-formed body with a second die arranged around the first die to obtain a processed material.
(2) The press-forming shearing method according to (1) above, wherein the shearing is started at the same time as or after the completion of the press-forming.
(3) The press-molded shearing method according to (1) or (2) above, wherein the material to be processed is a steel sheet having a tensile strength of 590 MPa or more.
(4) The press-molded shearing method according to (1) or (2) above, wherein the material to be processed is a steel sheet having a tensile strength of 1180 MPa or more.
(5) The processed material has a curved shape and has a curved shape.
The press-formed body has a cutting allowance to be cut off by the shearing process at a position of 0.8 r or less with respect to the median value r of the radius of curvature of the processed material.
The shearing process involves cutting off the cutting allowance.
The press forming shearing method according to any one of (1) to (4) above.
(6) The processed material has a curved shape and has a curved shape.
The press-formed body has a cutting allowance to be cut off by the shearing process at a position of 0.5 r or less with respect to the median value r of the radius of curvature of the processed material.
The shearing process involves cutting off the cutting allowance.
The press forming shearing method according to any one of (1) to (4) above.
(7) The press-molded shearing method according to (5) or (6) above, wherein the press-molded body has the cutting allowance at a portion that becomes an inner peripheral portion of the processed material.
(8) A press-molded shearing device that press-molds and shears the work material.
A convex first die having a protruding central portion and a peripheral portion, a second die arranged around the first die, and a concave shape arranged at a position facing the first die. Punch or
A convex punch having a protruding central portion and a peripheral portion, a concave first die arranged at a position facing the punch, and a second die arranged around the first die. ,
A press molding mechanism in which at least one of the punch and the first die is driven in the plate thickness direction of the work material to press-mold the work material to obtain a press-molded body, and the punch and the first die. While pressing the press-molded body with the die, at least one of the punch and the second die is driven in the plate thickness direction of the work material, and the press-molded body is sheared to obtain the processed material. Get, shearing mechanism,
A press-formed shearing machine equipped with.
(9) In the direction parallel to the moving direction of the punch, the position of the end surface of the second die facing the work piece is closer to the punch side than the position of the surface of the peripheral portion of the first die. The press-molded shearing apparatus according to (8) above, which protrudes within a range of 2 mm.
(10) In a direction parallel to the moving direction of the punch, the position of the end surface of the second die facing the work piece is the same as the position of the surface of the peripheral portion of the first die, or the first The press-molded shearing apparatus according to (9) above, which is on the side opposite to the punch side from the position of the surface of the peripheral portion of the die 1.

According to the method of the present disclosure, a press-formed processed material having excellent dimensional accuracy can be obtained.

FIG. 1 is a schematic cross-sectional view illustrating an example of an arrangement process in the method of the present disclosure. FIG. 2 is a schematic cross-sectional view illustrating an example of a press forming process in the method of the present disclosure. FIG. 3 is a schematic cross-sectional view illustrating an example of a shearing process in the method of the present disclosure. FIG. 4 is a schematic cross-sectional view illustrating an example of a process material taking-out process after press forming and shearing. FIG. 5 is a simulation model of the work material used in the examples. FIG. 6 is a simulation model of the processed material obtained by performing the press forming shearing process of the present disclosure on the material to be processed of FIG. FIG. 7 is a schematic cross-sectional view of the press-formed body after press forming and before shearing at the position corresponding to the broken line portion X of the processed material of FIG. FIG. 8 is a simulation model of the work material used in the comparative example. FIG. 9 is a simulation model of a press-molded body obtained by performing conventional press-molding on the work material of FIG. FIG. 10 is a schematic cross-sectional view taken along the broken line portion X of the press molded body 11 of FIG. FIG. 11 is a schematic view showing the measurement points of the principal stress. FIG. 12 is a schematic view showing a measurement point of the amount of deformation due to springback. FIG. 13 is a schematic view showing a measurement position of the deformation amount ΔD due to springback. FIG. 14 is a schematic cross-sectional view showing the relationship between the position of the surface of the peripheral portion of the first die and the position of the end portion of the second die. FIG. 15 is a schematic cross-sectional view illustrating an example of the arrangement process in the method of the present disclosure. FIG. 16 is a schematic cross-sectional view illustrating an example of a press forming process in the method of the present disclosure. FIG. 17 is a schematic cross-sectional view illustrating an example of a shearing process in the method of the present disclosure. FIG. 18 is a simulation model of the processed material obtained by performing the press forming shearing process of the present disclosure.

In the method of the present disclosure, the work material is press-molded using a punch and a die, and the press-molded body is pressed by the punch and the die used in the press molding as it is, and the punch and the die are arranged around the punch and the die. Shearing is performed with the die of No. 1 to obtain a processed material.

In the present disclosure, a work material having a first surface and a second surface on the opposite side thereof is arranged on the second surface side of the work material and has a convex central portion and a peripheral portion. Arranged between the die and the concave punch arranged on the first surface side of the work material and facing the first die, or on the first surface side of the work material. Between a convex punch having a protruding central portion and a peripheral portion and a concave first die arranged on the second surface side of the work material and arranged so as to face the punch. To obtain a press-molded body by press-molding the work material with the punch and the first die, and while pressing the press-molded body with the punch and the first die. The subject is a press-molded shearing method, which comprises shearing the press-formed body with a second die arranged around the punch and the first die to obtain a processed material.

According to the present disclosure, springback can be suppressed by cutting the outer peripheral portion of the press-formed body having a relatively large stress by shearing while holding down the press-formed body in which the stress is generated, so that the dimensional accuracy is excellent. A press-molded body can be obtained.

Hereinafter, the method of the present disclosure will be described with reference to the drawings.

In the method of the present disclosure, a work material having a first surface and a second surface on the opposite side thereof is arranged on the second surface side of the (A) work material and has a convex shape having a protruding central portion and a peripheral portion. Between the first die of No. 1 and the concave punch arranged on the first surface side of the work material and facing the first die, or (B) the first surface of the work material. A convex punch arranged on the side and having a protruding central portion and a peripheral portion, and a concave first die arranged on the second surface side of the work piece and arranged so as to face the punch. In between, it includes a placement step of placement.

FIG. 1 shows a schematic cross-sectional view illustrating an example of the arrangement process in the case of (A) above. As shown in FIG. 1, a work material 10 having a first surface 101 and a second surface 102 on the opposite side thereof is arranged on the second surface 102 side of the work material 10 and has a protruding central portion 31 and a peripheral portion. Between the convex first die 30 having 32 and the concave punch 20 arranged on the first surface 101 side of the work piece 10 and opposed to the first die 30. Deploy.

The convex-shaped first die 30 and the concave-shaped punch 20 are arranged so as to face each other with the workpiece 10 interposed therebetween. More specifically, in the convex-shaped first die 30 and the concave-shaped punch 20, the protruding central portion 31 of the first die 30 and the upper central portion 24 of the punch 20 face each other, and the first one. The peripheral portion 32 of the die 30 and the peripheral portion 22 of the punch 20 are arranged so as to face each other.

The method of arranging the work material 10 is not particularly limited, and the work material 10 may be placed on the central portion 31 of the first die 30, or the work material 10 may be placed on the first die 30 and the punch 20. It may be gripped by a holding member so as to be arranged between and.

Preferably, the holder 50 is placed around the punch 20. The holder 50 is preferably connected to the upper end 23 of the punch 20 by a spring 51. The holder 50 can suppress the vibration of the work piece 10 generated at the time of cutting, and can suppress the damage of the tool.

Preferably, the presser member 70 is arranged inside the punch 20. The presser member 70 can perform molding while restraining the workpiece 10 from the start to the end of molding. The pressing member 70 is preferably connected to the upper central portion 24 of the punch 20 by a spring 71. By connecting the pressing member 70 to the upper central portion 24 of the punch 20 with a spring 71, it is possible to more easily perform molding while restraining the workpiece 10 from the start to the end of molding.

FIG. 15 shows a schematic cross-sectional view illustrating an example of the arrangement process in the case of the above (B). As shown in FIG. 15, the work material 10 having the first surface 101 and the second surface 102 on the opposite side thereof is arranged on the first surface side 101 of the work material 10 and has a protruding central portion 21 and a peripheral portion. It is arranged between the convex punch 20 having 22 and the concave first die 30 arranged on the second surface 102 side of the work piece 10 and opposed to the punch 20.

The convex punch 20 and the concave first die 30 are arranged so as to face each other with the workpiece 10 interposed therebetween. More specifically, the convex punch 20 and the concave first die 30 have a protruding central portion 21 of the punch 20 and a lower central portion 36 of the first die 30 facing each other, and the punch 20 has a convex shape. The peripheral portion 22 and the peripheral portion 32 of the first die 30 are arranged so as to face each other.

The method of arranging the work material 10 is not particularly limited, and the work material 10 may be placed on the first die 30, or the work material 10 may be placed between the first die 30 and the punch 20. It may be gripped by a holding member so that it is arranged.

Preferably, the holder 50 is placed around the punch 20. The holder 50 is preferably connected to the upper end 23 of the punch 20 by a spring 51. The holder 50 can suppress the vibration of the work material generated at the time of cutting, and can suppress the damage of the tool.

Preferably, the presser member 70 is placed inside the die 30. The presser member 70 can perform molding while restraining the workpiece 10 from the start to the end of molding. The pressing member 70 is preferably connected to the lower central portion 36 of the first die 30 by a spring 71. By connecting the pressing member 70 to the lower central portion 36 of the first die 30 with a spring 71, it is possible to more easily perform molding while restraining the workpiece 10 from the start to the end of molding.

The method of the present disclosure includes a press molding step of press molding a work material with a punch and a first die to obtain a press molded body.

FIG. 2 shows a schematic cross-sectional view illustrating an example of the press molding process when the arrangement process is the above (A). As shown in FIG. 2, the work material is press-molded with the punch 20 and the first die 30 to obtain a press-molded body 11.

The punch 20 moves toward the first die 30 in the plate thickness direction of the work material 10 to a position where it stops by sandwiching the peripheral portion of the press molded body 11 with the peripheral portion 32 of the first die 30. .. The first die 30 may move toward the punch 20 in the plate thickness direction of the processed material 10. The punch 20 may move toward the first die 30 in the plate thickness direction of the workpiece 10, and the first die 30 may move toward the punch 20 in the plate thickness direction of the processed material 10. .. At the stopping position, the press molded body 11 may be sandwiched between the upper central portion 24 of the punch 20 and the protruding central portion 31 of the first die 30.

Preferably, the peripheral portion of the press molded body 11 is sandwiched and pressed between the holder 50 arranged around the punch 20 and the second die 40 arranged around the first die 30. As a result, the press-formed body 11 can be held more stably.

Preferably, press molding is performed while holding the central portion of the work piece 10 between the pressing member 70 arranged inside the punch 20 and the central portion 31 of the first die 30. As a result, press molding can be performed more stably. Preferably, shearing is also performed while holding the central portion of the work piece 10 between the pressing member 70 and the central portion 31 of the first die 30. As a result, a processed material that is more stable and has excellent dimensional accuracy can be obtained.

In the method of the present disclosure, while pressing the press-formed body with the punch and the first die, the press-formed body is sheared with the punch and the second die arranged around the first die. Includes a shearing process to obtain the material.

FIG. 16 shows a schematic cross-sectional view illustrating an example of the press molding process when the arrangement process is the above (B). As shown in FIG. 16, the work material is press-molded with the punch 20 and the first die 30 to obtain a press-molded body 11.

The punch 20 has a peripheral portion of the press molded body 11 between the peripheral portion 22 of the punch 20 and the peripheral portion 32 of the first die 30 in the plate thickness direction of the work material 10 toward the first die 30. Move to the position where it stops. The first die 30 may move toward the punch 20 in the plate thickness direction of the processed material 10. The punch 20 may move toward the first die 30 in the plate thickness direction of the workpiece 10, and the first die 30 may move toward the punch 20 in the plate thickness direction of the processed material 10. .. At the stopping position, the press molded body 11 may be sandwiched between the lower central portion 36 of the first die 30 and the protruding central portion 21 of the punch 20.

Preferably, the peripheral portion of the press molded body 11 is sandwiched and pressed between the holder 50 arranged around the punch 20 and the second die 40 arranged around the first die 30. As a result, the press-formed body 11 can be held more stably.

Preferably, the pressing member 70 (not shown) arranged inside the first die 30 and the protruding central portion 21 of the punch 20 are pressed while sandwiching the central portion of the work piece 10. I do. As a result, press molding can be performed more stably. Preferably, shearing is also performed while holding the central portion of the work piece 10 sandwiched between the pressing member 70 and the protruding central portion 21 of the punch 20. As a result, a processed material that is more stable and has excellent dimensional accuracy can be obtained.

FIG. 3 shows a schematic cross-sectional view illustrating an example of the shearing process when the arrangement process is the above (A). As shown in FIG. 3, while pressing the press-formed body with the punch 20 and the first die 30, the press-formed body is pressed with the punch 20 and the second die 40 arranged around the first die 30. Shearing is performed to obtain a processed material 12.

The first die 30 is preferably located on the pedestal 60 via a spring 33. The second die 40 is preferably located on the pedestal 60. The spring 33 is expandable and contractible, but preferably has a spring constant that does not substantially shrink during press forming and contracts during shearing. In another method, preferably, during press forming, the first die 30 is fixed on the pedestal 60 with a fixing member so that the first die 30 does not move due to the force from the punch 20, and the shearing process is performed. At that time, the fixing member is removed, and the spring 33 contracts.

Although stress is generated in the press-formed body, shearing is performed while pressing the press-formed body with the punch 20 and the first die 30 without removing the press-formed body from the punch 20 and the first die 30. By doing so, it is possible to perform shearing to a stable shape, and it is also possible to reduce the stress of the processed material after shearing.

When the processed material 12 is obtained by shearing, the end portion 13 of the press-formed body is cut off.

Preferably, the shearing process is performed while sandwiching and pressing the peripheral portion of the press molded body 11 between the holder 50 and the second die 40. Thereby, the surface property of the sheared surface can be improved.

The clearance between the punch 20 and the second die 40 in the direction perpendicular to the plate thickness direction of the work material is preferably 5 to 25% of the plate thickness. By setting the clearance within the above range, defects in the end face can be suppressed.

Shearing is started at the same time as the press forming is substantially completed or after the press forming is completed. Substantially complete includes the time point before the press molding is completely completed. If the press forming is substantially completed, the increase in stress in the press-formed body is suppressed after the shearing process, so that the springback is suppressed and the press-formed processed material having excellent dimensional accuracy can be obtained. it can. It is also possible to reduce noise and suppress wear of the shear blade.

Shearing is preferably started when the press forming is complete or after the press forming is complete. By starting the shearing process at the same time as or after the press forming is completed, there is no increase in the stress generated in the press-formed body after the shearing process, so that the springback is more suppressed and the press has better dimensional accuracy. A molded processed material can be obtained. In addition, noise can be further reduced and wear of the shear blade can be further suppressed.

The press-molded product is preferably a hat-type molded product having a web portion, a flange portion, and an arm portion.

FIG. 17 shows a schematic cross-sectional view illustrating an example of the shearing process when the arrangement process is the above (B). As shown in FIG. 17, while pressing the press-formed body with the punch 20 and the first die 30, the press-formed body is pressed with the punch 20 and the second die 40 arranged around the first die 30. Shearing is performed to obtain a processed material 12. Other configurations in the shearing process are the same as in the case where the arrangement process is the above (A).

After obtaining the processed material in the shearing process, the processed material is collected. When collecting the processed material, at least one of the punch and the first die is moved in parallel with the pressing direction, and the punch and the first die are separated to collect the processed material.

FIG. 4 shows a schematic cross-sectional view illustrating an example of recovering the processed material when the arrangement step is the above (A). As shown in FIG. 4, at least one of the punch 20 and the first die 30 is moved parallel to the pressing direction (shearing direction), and the punch 20 and the first die 30 are separated from each other to separate the processed material. to recover. The same applies when the arrangement step is the above (B).

The material to be processed used in the method of the present disclosure is preferably a metal member. The work material is preferably a steel sheet having a tensile strength of 590 MPa or more, more preferably 1180 MPa or more. As the strength of the work material increases, the generated stress and strain in press forming and shearing tend to increase. However, by applying the method of the present disclosure, the generated stress is reduced and the processed material has excellent dimensional accuracy. Can be obtained.

As the material to be processed, a material having a width corresponding to the cutting allowance at which the end portion 13 of the press-formed body is separated by shearing is used. The position of the cutting allowance in the press-formed body may be the entire portion of the processed material or a part thereof. When the curved material 12 as illustrated in FIG. 6 is obtained, the cutting allowance in the press-formed body is the straight portions 12A and 12B of the processed material 12, and the ends of the inner peripheral side 12D and the outer peripheral side 12E of the curved portion 12C. It may be formed in the whole part which becomes a part, or may be formed in a part.

The cutting allowance in the press-molded body is preferably provided at least at the stress concentration portion where the stress is concentrated in the press-molded body at the bottom dead center of molding. The stress concentration portion can be obtained in advance by a blank molding simulation on the premise that there is no end portion of the molded body to be separated.

The stress concentration portion may be a portion having a small radius of curvature in the curved work material. In the processed material 12 shown in FIG. 6, the curved portion 12C has an inner peripheral side 12D and an outer peripheral side 12E, and the radius of curvature is the smallest on the inner peripheral side 12D. In the press-formed body, a cutting allowance is provided at a portion on the inner peripheral side 12D of the curved processed material, and the cutting allowance (end portion 13 of the press-formed body) is cut off by shearing to obtain the method of the present disclosure. The springback of the processed material to be processed can be reduced more effectively.

Preferably, the press-formed body has a cutting allowance cut off by shearing at a position preferably 0.8 r or less, more preferably 0.5 r or less, with respect to the median radius of curvature r of the end portion of the processed material. Has. The median value r of the radius of curvature is the median value of the entire circumference of the end portion of the processed material.
The cutting allowance in the press-formed body is more preferably provided at a position having the preferred radius of curvature and on the inner peripheral side of the curved processed material. This will be described with reference to the simulation model of the processed material obtained by performing the press forming shearing process of the present disclosure illustrated in FIG. The processed material 12 illustrated in FIG. 18 has straight portions 12A and 12B, and a curved portion 12C having an inner peripheral side 12D and an outer peripheral side 12E, and has the smallest radius of curvature on the inner peripheral side 12D of the curved portion 12C. The press-molded body can have a cutting allowance 11F at a position on the inner peripheral side 12D of the processed material 12.

The width of the cutting allowance is preferably 2 mm or more, more preferably 10 mm or more. The width of the cutting allowance is the width 13A on one side of the end portion 13 of the press-formed body to be separated, which is exemplified in FIGS. 3 and 17. By setting the width of the cutting allowance within the above range, the springback reduction effect due to stress reduction can be obtained more stably. Further, by setting the width of the cutting allowance within the above range, it is possible to prevent stress from concentrating on the cutting edge during shearing and further suppress damage to the tool. The upper limit of the width of the cutting allowance is not particularly limited, but may be, for example, 30 mm.

The thickness of the work material is preferably 0.5 to 4.0 mm. When the thickness of the work material is within the above-mentioned preferable range, damage to the blade during shearing (trim) can be suppressed and a good sheared end face can be obtained.

The work material is preferably a plate-shaped member having at least a curved shape as illustrated in FIG. When a curved plate-shaped member is press-formed, the generated stress and strain tend to be particularly large. However, by applying the method of the present disclosure, the generated stress is reduced and a processed material having excellent dimensional accuracy can be obtained. be able to.

The method of the present disclosure is particularly effective in obtaining a curved processed material in which the stress distribution generated in the processed material is complicated, but of course, it can also be applied in the case of obtaining a linear processed material.

The present disclosure is also a press-molded shearing apparatus that press-molds and shears a material to be processed, and is a convex first die having a protruding central portion and a peripheral portion, around the first die. A second die arranged and a concave punch arranged at a position facing the peripheral portion of the first die, or a convex punch having a protruding central portion and a peripheral portion, facing the punch. A concave first die arranged at a position to be formed and a second die arranged around the first die are provided, and at least one of the punch and the first die is used as the work material. The punch and the first die while pressing the press-molded body with the punch and the first die, and a press-molding mechanism for pressing and molding the work material in the plate thickness direction to obtain the press-molded body. A press-molded shearing apparatus further provided with a shearing mechanism for driving at least one of the two dies in the plate thickness direction of the material to be processed and shearing the press-formed body to obtain a processed material. set to target.

An example of the press forming shearing apparatus of the present disclosure is shown in FIGS. 1 and 15. The above description of the press forming shearing method also applies to the press forming shearing apparatus.

The press forming mechanism is connected to at least one of the punch and the first die, and drives at least one of the punch and the first die in the plate thickness direction of the workpiece to press form the workpiece. Can be done.

The shearing mechanism is connected to at least one of the punch and the second die, and at least one of the punch and the second die is driven in the plate thickness direction of the work piece to shear the press-formed body. it can. When shearing, the punch and the first die hold the press-molded body, but the press-molding mechanism may be connected to the punch and the first die to control the drive of the punch and the first die. A shearing mechanism may be connected to the punch and the first die to control the drive of the punch and the first die.

In the direction parallel to the movement direction of the punch (direction parallel to the plate thickness direction of the work material), the position of the end face of the second die facing the work material is higher than the position of the surface of the peripheral portion of the first die. It may protrude toward the punch side preferably within a range of 2 mm, more preferably within a range of 1 mm.

FIG. 14 shows the distance H2 from the pedestal 60 of the end surface of the second die 40 facing the work piece 10 in the direction parallel to the movement direction of the punch when the arrangement step is the above (A), and the first. The relationship with the distance H1 from the pedestal 60 on the surface of the peripheral portion 32 of the die 30 is shown. It is preferably H2 ≦ H1 + 2 mm, and more preferably H2 ≦ H1 + 1 mm. By setting the relative position between the end face of the second die facing the workpiece and the surface of the peripheral portion of the first die within the above range, the press molding is substantially completed and the shearing process is started at the same time. Therefore, the stress generated in the processed material obtained by shearing can be further reduced. The same applies to the case where the arrangement step is the above (B).

More preferably, in the direction parallel to the moving direction of the punch (direction parallel to the plate thickness direction of the work material), the position of the end face of the second die facing the work material is the surface of the peripheral portion of the first die. Is the same as the position of, or is on the side opposite to the punch side from the position of the surface of the peripheral portion of the first die. That is, more preferably H2 ≦ H1. By setting the relative position between the end face of the second die facing the workpiece and the surface of the peripheral portion of the first die within the above range, shearing is started at the same time as or after the press molding is completed. Therefore, the stress generated in the processed material obtained by shearing can be further reduced. The same applies to the case where the arrangement step is the above (B).

The materials and shapes of the first die, the second die, and the punch can be the same as those used in conventional press forming and conventional shearing. The material and shape of the holder and the presser member can also be the same as those used in the conventional press molding and the conventional shearing process.

(Evaluation of deformation by generated stress and springback)
The stress and deformation of the processed material after press forming and shearing were evaluated by simulation. The simulation conditions are as follows:
The tool is a rigid body;
The work material is an elasto-plastic body, 1470 MPa class steel sheet, Young's modulus 200 GPa, Poisson's ratio 0.3, plate thickness 1.6 mm;
The solver is Abaqus;
Molding analysis is dynamic explicit method (FEM);
Springback analysis is a static implicit method (FEM).

(Example 1)
A plate-shaped workpiece 10 having a curved shape and a width of 300 mm as shown in FIG. 5 was prepared as a simulation model. The work material 10 was integrally composed of straight portions 10A and 10B having a length of 300 mm and curved portions 10C having a median radius of curvature of 860 mm.

The work material 10 of FIG. 5 is subjected to the press molding shearing of the present disclosure shown in FIGS. 1 to 4, the processed material shown in FIG. 4 is taken out, and the work material 10 is formed into a hat mold shown in FIG. Material 12 was obtained. FIG. 6 is a simulation model of the processed material obtained by performing the press forming shearing process of the present disclosure on the material to be processed of FIG. The press-formed shearing apparatus used had punches, dies, holders, holding members, and the like having shapes corresponding to the straight portions 10A and 10B and the curved portions 10C of the work material 10 shown in FIG.

In the hat-shaped processed material 12 shown in FIG. 6, a straight portion 12A and 12B having a length of 300 mm and a curved portion 12C having an inner peripheral side 12D having a median radius of curvature of 860 mm are integrally formed. It was composed.

FIG. 7 is a schematic cross-sectional view of the press-formed body 11 after press forming and before shearing at the position corresponding to the broken line portion X of the processed material 12 of FIG. Since the work material is plate-shaped and has a thickness, the press-formed body also has a thickness, but it is schematically represented by a linear shape. The press-formed body 11 has a hat-shaped structure having a web portion having a width of 65 mm, a flange portion having a height of 60 mm, and an arm portion having a width of 75 mm in a cross section, and a curvature between the flange portion and the arm portion. It had a curved shape with a radius of 10 mm.

In the shearing process of the present disclosure, as shown in FIG. 7, a position 20 mm wide from the end portion of the entire two arm portions of the press-molded article 11 is sheared (trimmed) into a hat shape shown in FIG. A molded processed material 12 was obtained.

(Comparative Example 1)
A plate-shaped workpiece 10 having a curved shape and a width of 280 mm as shown in FIG. 8 was prepared as a simulation model. The work material 10 was integrally composed of straight portions 10A and 10B having a length of 300 mm and curved portions 10C having a median radius of curvature of 860 mm.

The work material 10 was press-molded according to the prior art to obtain a press-molded body 11 molded into the hat mold shown in FIG. FIG. 9 is a simulation model of a press-molded body obtained by performing conventional press-molding on the work material of FIG.

In the press-molded body 11 molded into the hat shape shown in FIG. 9, straight portions 11A and 11B having a length of 300 mm and a curved portion 11C having an inner peripheral side 11D having a median radius of curvature of 860 mm are integrated. It consisted of.

FIG. 10 is a schematic cross-sectional view taken along the broken line portion X of the press molded body 11 of FIG. The material to be processed is plate-shaped and has a thickness, but is schematically represented by a linear shape. The press-formed body 11 has a hat-shaped structure having a web portion having a width of 65 mm, a flange portion having a height of 60 mm, and an arm portion having a width of 55 mm in a cross section, and a curvature between the flange portion and the arm portion. It had a curved shape with a radius of 10 mm.

(Simulation result of generated stress)
The main stress of the processed material (state in FIG. 3) pressed by the punch and the first die before being removed from the die after shearing in Example 1, and before being removed from the die after press molding in Comparative Example 1. The principal stress of the press-formed body pressed with a punch and a die was calculated under the above simulation conditions. As shown in FIG. 11, the measurement point of the principal stress is 12D on the inner peripheral side of the curved portion. The calculation results of the principal stress are shown in Table 1.

(Simulation result of deformation amount by springback)
The amount of deformation due to springback of the processed material after being removed from the mold after shearing in Example 1 and the amount of deformation due to springback of the press-molded body after being removed from the mold after press molding in Comparative Example 1 are described above. Calculated under simulation conditions.

As shown in FIG. 12, the point where the amount of deformation due to the springback is measured is the end of the straight portion, and as shown in FIG. 13, the processed material (Example 1) and the press-formed body with respect to the end position of the target shape. The displacement amount ΔD at the end position of (Comparative Example 1) was defined as the deformation amount due to springback. Table 2 shows the calculation results of the amount of deformation due to springback. The target shape is substantially the same as the shape of the processed material (Example 1) and the press-formed body (Comparative Example 1) before being removed from the mold.

As in Comparative Example 1, when the press-molded body is taken out from the die after press molding and sheared with another die, the amount of deformation due to springback is large, so a processed material with good dimensional accuracy can be obtained by shearing. Although it cannot be obtained, in Example 1, a processed material having a small amount of deformation due to springback and good dimensional accuracy can be obtained.

(Blade wear, noise evaluation)
(Example 2)
The work material was actually press-formed and sheared under the conditions of Example 1.

(Comparative Example 2)
The work material was actually press-formed under the conditions of Example 1. Next, the press-formed body is removed from the punch and the first die, and another shearing device is used to shear the press-formed body at the same location as in Example 1 (at a position 20 mm from the end of the arm portion). went. The shear blade (punch) and die of another shearing apparatus had the same shape as the punch and die of the press forming shearing apparatus of the present disclosure, and were made of the same material (SKD11).

(Blade wear evaluation result)
The damaged state of the punch in Example 2 and the damaged state of the shear blade in Comparative Example 2 were compared. Table 3 shows the number of shots when the punch (Example 2) and the shear blade (Comparative Example 2) are missing. The number of shots is the number of shearing operations. In Comparative Example 2, the shear blade was lost in one shot, whereas in Example 2, there was no loss in the punch even after 500 shots.

(Noise evaluation result)
The noise during shearing in Example 2 and Comparative Example 2 was compared. Table 4 shows the evaluation values of the A specific sound pressure level, and Table 5 shows the noise evaluation results. In Example 2, the noise was reduced as compared with Comparative Example 2.

10 Work material 10A, 10B Straight part of work material 10C Curved part of work material 11 Press molded body 11A, 11B Straight part of press molded body 11C Curved part of press molded body 11D Inner circumference side of press molded body 11E Press Outer circumference side of the molded body 11F Cutting allowance 12 Processed material 12A, 12B Straight part of the processed material 12C Curved part of the processed material 12D Inner peripheral side of the processed material 12E Outer circumference side of the processed material 13 Press molding end 13A to be separated Width of one side of the end of the body 20 Punch 21 Protruding center of the punch 22 Periphery of the punch 23 Top of the punch 24 Upper center of the punch 30 First die 31 Protruding center of the first die 32 No. Peripheral part of 1 die 33 Spring 36 Lower center part of 1st die 40 2nd die 50 Holder 51 Spring 60 Pedestal 70 Presser member 71 Spring

Claims (10)

A work material having a first surface and a second surface on the opposite side thereof
A convex first die arranged on the second surface side of the work material and having a protruding central portion and a peripheral portion, and a convex first die arranged on the first surface side of the work material and having a protruding central portion and a peripheral portion. A convex punch arranged between the concave punches arranged so as to face the peripheral portion or having a central portion and a peripheral portion arranged on the first surface side of the material to be processed and having a protruding central portion and a peripheral portion, and the subject. Between the concave first die arranged on the second surface side of the work material and arranged so as to face the peripheral portion of the punch.
To place,
The work material is press-molded with the punch and the first die to obtain a press-molded body, and the punch and the punch while pressing the press-molded body with the punch and the first die. A press-molding shearing method comprising shearing the press-formed body with a second die arranged around the first die to obtain a processed material. The press-forming shearing method according to claim 1, wherein the shearing is started at the same time as or after the completion of the press-forming. The press-formed shearing method according to claim 1 or 2, wherein the material to be processed is a steel sheet having a tensile strength of 590 MPa or more. The press-formed shearing method according to claim 1 or 2, wherein the material to be processed is a steel sheet having a tensile strength of 1180 MPa or more. The processed material has a curved shape and
The press-formed body has a cutting allowance to be cut off by the shearing process at a position of 0.8 r or less with respect to the median value r of the radius of curvature of the processed material.
The shearing process involves cutting off the cutting allowance.
The press forming shearing method according to any one of claims 1 to 4. The processed material has a curved shape and
The press-formed body has a cutting allowance to be cut off by the shearing process at a position of 0.5 r or less with respect to the median value r of the radius of curvature of the processed material.
The shearing process involves cutting off the cutting allowance.
The press forming shearing method according to any one of claims 1 to 4. The press-molded shearing method according to claim 5, wherein the press-molded body has the cutting allowance at a portion that becomes an inner peripheral portion of the processed material. A press-molding shearing device that press-molds and shears the work material.
A convex first die having a protruding central portion and a peripheral portion, a second die arranged around the first die, and a concave shape arranged at a position facing the first die. Punch or
A convex punch having a protruding central portion and a peripheral portion, a concave first die arranged at a position facing the punch, and a second die arranged around the first die. ,
A press molding mechanism in which at least one of the punch and the first die is driven in the plate thickness direction of the work material to press-mold the work material to obtain a press-molded body, and the punch and the first die. While pressing the press-formed body with the die, at least one of the punch and the second die is driven in the plate thickness direction of the work material, and the press-molded body is sheared to obtain the processed material. Get, shearing mechanism,
A press-formed shearing machine equipped with. In the direction parallel to the moving direction of the punch, the position of the end surface of the second die facing the work piece is within 2 mm on the punch side of the position of the surface of the peripheral portion of the first die. The press-formed shearing apparatus according to claim 8, which protrudes in a range. In a direction parallel to the moving direction of the punch, the position of the end surface of the second die facing the workpiece is the same as the position of the surface of the peripheral portion of the first die, or the first die. The press-molded shearing apparatus according to claim 9, which is on the side opposite to the punch side from the position of the surface of the peripheral portion of the above.