JP5782877B2 - Bending wrinkle correction method, and method for forming a member having a cross-sectional groove shape using the bending wrinkle correction method - Google Patents

Description

  The present invention relates to a bending wrinkle correction method and a method for forming a member having a cross-sectional groove shape using the bending wrinkle correction method.

In some cases, a member having a groove shape with a deep cross section, such as the component member 25 of the vehicle 23 shown in FIGS. If such a groove shape is press-molded at once using a die (die) having a deep recessed portion, a ridge 27 is generated as shown in a circled region in FIG. 7, and proper molding cannot be performed. There is a case.
In such a case, as shown in FIG. 8, first, a mold having a shallow groove is formed so that the cross section has a hat shape as shown in FIG. 8A, and then the flange portion 29 in the hat shape is formed. It can be considered that the bent portion 31 is flattened by bending the bent portion 31 at the base of the plate in the direction opposite to the bending direction.

  However, if the bent portion 31 is bent in the direction opposite to the bent direction, the bent portion 33 having an uneven shape remains as shown in FIG. . In this case, it is conceivable to apply a high load to crush and flatten the uneven shape of the bending rod 33, but there is a limit to the rigidity of the mold and the capability of the pressing device, and the uneven shape remains, and the bending 33 cannot be completely corrected.

  As a method of correcting the shape defect having the curvature generated in the groove-shaped vertical wall as described above, for example, as shown in Patent Documents 1 and 2, an uneven shape is provided on the punch or die side and the vertical wall portion is pressed. Technology is disclosed.

Japanese Patent No. 3745202 Japanese Patent No. 3750421

However, the techniques disclosed in Patent Documents 1 and 2 are intended for a wide range of curvature such as warpage occurring in a groove-shaped vertical wall, and the bending rod 33 having a local uneven shape as described above. Cannot cope with the correction of
Thus, conventionally, there is no bending wrinkle correction method that can effectively correct a bending wrinkle having a local concavo-convex shape, and therefore, there is a problem that a cross-sectional groove-shaped member having a deep groove cannot be formed. is there.

  The present invention has been made to solve such a problem, and a bending wrinkle correction method capable of effectively correcting a bending wrinkle having a local uneven shape, and a member having a cross-sectional groove shape using the bending wrinkle correction method It aims at providing the shaping | molding method which shape | molds.

(1) The bending wrinkle correction method according to the present invention is a local bending wrinkle that occurs when a bent portion of a metal plate is bent in a direction opposite to the bending direction to make the bent portion substantially flat. In the center, there is a large convex portion having a large curvature, and a local bending ridge formed by forming a small convex portion having a curvature smaller than that of the large convex portion on both sides and convex on the opposite side of the large convex portion. Bending wrinkle correction method to correct and flatten the surface ,
A step of fixing the metal plate having the local bending fold to the die by providing a gap below the local bending ridge of the metal plate, and the large convex portion of the local bending ridge of the metal plate . A convex punch having a curvature smaller than the curvature is within a range smaller than a distance twice the thickness of the metal plate from the convex side of the large convex part to the opposite side of the convex side in the local bending rod. A first correction step of forming a curved shape having a curvature that is convex in the opposite direction to the local bending wrinkles of the large convex portion ; and the metal plate corrected by the first correction step is converted into Young's modulus A second correction step of correcting the metal plate so as to be pushed into the opposite side from the convex side of the metal plate to the opposite side by a convex punch having a curvature at the tip, sandwiched by an elastic body of 0.03 GPa or more; It is characterized by this.

(2) Further, in the above-mentioned (1), the elastic body is characterized by being highly repulsive urethane, high load urethane or silicone rubber.

(3) A method for forming a member having a cross-sectional groove shape according to the present invention is a method for forming a member having a cross-sectional groove shape using the bending wrinkle correction method described in (1) or (2) above. ,
A first forming step of forming the metal plate into a substantially hat-shaped cross section, and a second forming step of making the bent portion substantially flat by bending the bent portion at the base of the flange portion in the hat shape in a direction opposite to the bending direction; A bending wrinkle correction step of correcting the bending wrinkles generated in the second step, wherein the bending wrinkle correction step uses the bending wrinkle correction method described in (1) or (2) above. is there.

  According to the present invention, the bending bend generated when the bent portion of the metal plate is bent in the direction opposite to the bending direction to make the bent portion flat is surely corrected and flattened without applying excessive pressing force. Can be a surface.

It is explanatory drawing of the bending wrinkle correction method which concerns on one embodiment of this invention. It is detailed explanatory drawing of the 1st correction process in the bending wrinkle correction method shown in FIG. It is detail explanatory drawing of the 2nd correction process in the bending wrinkle correction method shown in FIG. It is explanatory drawing of the shaping | molding method of the member which has a cross-sectional groove shape in one embodiment of this invention. It is explanatory drawing of the member of a cross-sectional groove shape shape | molded using the bending wrinkle correction method which concerns on this invention. It is sectional drawing which follows the arrow AA line of FIG. It is explanatory drawing of the subject which this invention tends to solve, and is explanatory drawing of the problem at the time of shape | molding a cross-sectional groove shape in one process. It is explanatory drawing of the subject which this invention tends to solve, and is explanatory drawing of the method of shape | molding cross-sectional groove shape in two processes. It is explanatory drawing of the subject which this invention tends to solve, and is explanatory drawing of the bending wrinkles produced when it shape | molds with the method shown in FIG. FIG. 10 is an enlarged view of a portion A circled in FIG. 9.

[Embodiment 1]
A bending wrinkle correction method according to the present embodiment will be described with reference to FIGS.
In the bending wrinkle correction method according to the present embodiment, the V-shaped bent portion 3 of the metal plate 1 as shown in FIG. 1A is moved in the direction opposite to the bent direction (indicated by the arrow in FIG. 1A). This is a bending wrinkle correction method for correcting a bending wrinkle 5 having a corrugated uneven shape as shown in FIG. 1B, which is generated when the bent portion 3 is made substantially flat by bending in a direction). As shown in FIG. 1 (b), the bending rod 5 has a large convex portion 5a having a large curvature at the center, and has a small curvature that is smaller on the both sides than the convex portion and convex on the opposite side to the large convex portion 5a. The convex part 5b is formed.

The bending wrinkle correction method of the present embodiment for correcting the bending wrinkle 5 as described above has at least two steps of a first correction step and a second correction step. Hereinafter, each process will be described.
<First correction process>
In the first straightening step, as shown in FIG. 1 (c), the convex punch 7 having a curvature smaller than the curvature of the large convex portion 5a in the metal plate 1 is changed from the convex side of the large convex portion 5a to the convex side. Pushing in the opposite direction within a range smaller than twice the thickness of the metal plate 1, and forming a curved shape having a curvature convex in the opposite direction to the large convex portion 5a, as shown in FIG. It is a process to do.

  In an actual press molding machine, as shown in FIG. 2 (a), the metal plate 1 having the bending rod 5 is set on the die 9 so that the convex side of the large convex portion 5a faces upward and fixed by the fixing portion 11. To do. At this time, a gap 13 for pushing the metal plate 1 with the punch 7 is provided below the metal plate 1. In this state, the punch 7 is pressed against the metal plate 1 as shown in FIG.

  As shown in FIG. 1C, the pushing distance S of the punch 7 is set to S ≦ 2t, where t is the plate thickness. The reason why the distance S is set in this way is that when S> 2t, the bending generated in the first correction process becomes too large and cannot be corrected in the second correction process.

  The reason why the curvature of the punch 7 is smaller than the curvature of the large convex portion 5a of the bending rod 5 is that when the curvature of the punch 7 is larger than the curvature of the large convex portion 5a, the large convex portion 5a is pushed by the punch 7. In addition, the tip of the punch 7 collides with the flat portions of the metal plate 1 at both ends of the small convex portion 5b, so that the shape as shown in FIG. 1D, which is the object of the first correction process, cannot be formed.

<Second straightening process>
In the second straightening step, the metal plate 1 straightened in the curved shape as shown in FIG. 1 (d) in the first straightening step is turned upside down as shown in FIG. 1 (e) and converted into Young's modulus. It is sandwiched between elastic bodies 15 of 0.03 GPa or more, and corrected so that the punch 7 pushes in from the convex side to the opposite side of the convex shape of the metal plate 1 within a range of three times or less the plate thickness.

  In an actual press molding machine, as shown in FIG. 3, the metal plate 1 is placed on the die 17 with the elastic body 15 being sandwiched between them, and the punch 7 is pressed against the elastic body 15. At this time, a gap 19 is provided in the die 17 for the elastic body 15 to bend downward, and this gap 19 is a shape in which the side wall of the die forming the gap 19 is curved in consideration of the bending shape of the elastic body 15. I have to.

Examples of the elastic body 15 of 0.03 GP or more in terms of Young's modulus include high-rebound urethane, high-load urethane, or silicone rubber.
In the present embodiment, the punch 7 used in the second straightening process is the same as that used in the first straightening process. However, if the punch used in the second straightening process is curved in a convex shape, the curvature is not particularly limited as in the case of the first straightening process, so it must be the same as that used in the first straightening process. There is no.

The pressing amount G of the punch 7 (see FIG. 1E) is set to G ≦ 3t, where the plate thickness is t. The reason for this is that if the indentation distance G is G> 3t, in the second correction step, the bending that protrudes in the opposite direction to the convex shape formed in the first correction step (see FIG. 1 (d)) is performed. It will occur.
By obtaining the second straightening step, the bending wrinkles 5 made of unevenness as shown in FIG. 1B are straightened to become a flat surface (see FIG. 1F).

  According to the bending wrinkle correction method of the present embodiment, it is possible to reliably correct the bending wrinkles 5 to make a flat surface without applying an excessive pressing force.

[Embodiment 2]
The second embodiment relates to a molding method for molding a member having a cross-sectional groove shape using the bending wrinkle correction method of the first embodiment.
A method for forming a member having a cross-sectional groove shape according to the present embodiment will be described with reference to FIG.
The method for forming a member having a cross-sectional groove shape according to the present embodiment includes a first forming step of forming a metal plate into a substantially hat-shaped cross section (see FIG. 4A) (S1), and a flange portion in the hat shape. A second molding step (S2) for making the bent portion 3 substantially flat as shown in FIGS. 4 (b1) and 4 (b2) by bending the bent portion 3 at the base of A bending wrinkle correcting step (S3) for correcting the bent wrinkles 5 (see FIG. 1B) generated in the second step.
Each step will be described in more detail.

<First molding step>
In the first molding step, a mold having a groove depth shallower than the target cross-sectional groove shape is formed into a substantially hat shape as shown in FIG. At this time, since the groove depth is not so deep, wrinkles do not occur in the metal plate. In other words, in the first forming step, the metal plate is formed into a substantially hat shape using a mold having a depth that does not cause wrinkles on the metal plate.

<Second molding step>
In the second molding step, as shown in FIG. 4 (b1), the wrist-like mold 21 is inserted into the hat-shaped groove, and the bent portion 3 at the base of the flange portion in the hat shape is defined as the bending direction. The bent portion 3 is made substantially flat by bending in the opposite direction.
When the bent portion 3 is substantially flattened by the second molding step, the tip end side of the bent portion 3 is opened outward with respect to the target shape indicated by the broken line as shown in FIG. 4 (b2). Then, the bending rod 5 as shown in FIG. 1 (b) remains in the part surrounded by a circle in FIG. 4 (b2).

<Bending wrinkle correction process>
The bending wrinkle correction step is a step of correcting the bending wrinkle 5 remaining in the second step, and the bending wrinkle correction step uses the bending wrinkle correction method described in the first embodiment.
In other words, in the bending wrinkle correction step, a convex punch 7 having a curvature smaller than the curvature of the bending reed 5 of the metal plate is moved from the convex side of the bending reed 5 to the opposite side of the convex side by 2 of the thickness of the metal plate. A first straightening step for forming a curvature that is convex in the opposite direction to the indented bend ridge 5 in a range smaller than the double distance, and both surfaces of the metal plate straightened by the first straightening step are converted to 0 in terms of Young's modulus. A second straightening step in which the pin is sandwiched between elastic bodies 15 having a pressure of 0.03 GPa or more, and is corrected so as to be pushed into the opposite side of the metal plate from the convex side to the opposite side by a convex punch 7 having a curvature at the tip within a range of three times the plate thickness or less. Have.
By passing through the bending wrinkle correction step, a member having a cross-sectional groove shape is formed as shown in FIG.

  According to the present embodiment, even a groove shape having deep grooves can be formed without generating wrinkles.

DESCRIPTION OF SYMBOLS 1 Metal plate 3 Bending part 5 Bending hook 5a Large convex part 5b Small convex part 7 Punch 9 Die 11 Fixing part 13 Crevice 15 Elastic body 17 Die 19 Crevice 21 Wrist-like mold 23 Vehicle 25 Component member 27 ２９ 29 Flange part 31 Bending Part 33

Claims (3)

It is a local bending wrinkle that occurs when the bent portion of the metal plate is bent in the direction opposite to the bending direction, and has a large convex portion with a large curvature at the center. This is a bending wrinkle correction method that corrects local bending wrinkles that have small curvatures that are smaller in curvature than the large convex portions on both sides and that are formed on the opposite side of the large convex portions to make a flat surface. A step of fixing the metal plate having the local bending fold to the die by providing a gap below the local bending ridge of the metal plate, and the large convexity of the local bending ridge of the metal plate. A convex punch having a curvature smaller than the curvature of the part is smaller than a distance twice the thickness of the metal plate from the convex side of the large convex part to the opposite side of the convex side in the local bending rod. forming a curved shape having a local curl of the Daitotsu portion push range curvature that is convex in the opposite direction A first straightening step, and the metal plate straightened by the first straightening step is sandwiched between elastic bodies of 0.03 GPa or more in terms of Young's modulus, and the convex side of the metal plate is formed with a convex punch having a curvature at the tip. A bending wrinkle correction method comprising: a second correction step of correcting so as to be pushed into the opposite side within a range of not more than three times the plate thickness. 2. The bending wrinkle correction method according to claim 1, wherein the elastic body is high resilience urethane, high load urethane or silicone rubber. It is a shaping | molding method of the member which has a cross-sectional groove shape using the bending wrinkle correction method of Claim 1 or 2, Comprising: The 1st shaping | molding process which shape | molds a metal plate in cross-sectional substantially hat shape, The flange part in hat shape A second forming step for bending the bent portion at the base of the wire in a direction opposite to the bending direction to make the bent portion substantially flat, and a bending wrinkle correcting step for correcting local bending wrinkles generated in the second step. And the bending wrinkle correction process uses the bending wrinkle correction method according to claim 1 or 2 , and is a method for forming a member having a cross-sectional groove shape.

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