JP2017024066A - Press molding metal mold and press molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press molding metal mold in a hat cross-sectional shape in which spring back is suppressed, and a press molding method.SOLUTION: A press molding metal mold 1 molds a press molded article in a hat cross-sectional shape having a top plate part, a vertical wall part continuing from the top plate part, and a flange part continuing from the vertical wall part, and is provided with: a punch 3 having a top plate molding part 3a for molding the top plate part, and a vertical wall molding part 3b for molding the vertical wall part; a die 5 having a top plate molding part 5a for molding the top plate part, a vertical wall molding part 5b for molding the vertical wall part, and a flange molding part 5d for molding the flange part; wrinkle suppressors 7 arranged on both sides of the punch, movable in a press molding direction, and for molding at least a base end of the flange part in cooperation with the die; plate suppressors 9 oppositely arranged at a predetermined interval in the press molding direction of the wrinkle suppressors on the outside of the die, and movable with the wrinkle suppressors; and gap adjustment means 11 for adjusting a gap in the press molding direction between the plate suppressors and the wrinkle suppressors.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a press molding die and a press molding method, and more particularly, to a press molding die and a press molding method for suppressing spring back in a press molded product having a hat cross-sectional shape.

  In recent years, in order to achieve both improvement in collision safety and weight reduction of automobile bodies, the application of ultra-high tensile materials of 980 MPa or more to vehicle body structural parts is progressing. Super high-tensile materials have high yield strength and tensile strength, and low properties such as elongation. Therefore, molding defects such as cracks, wrinkles, and springback are problems in press forming. Accordingly, the shape of a part manufactured by press molding is often simplified. However, recently, there is a demand for parts having a complicated shape from the viewpoint of improving the rigidity and strength of the part connecting portion, and it is considered that application of drawing is necessary in the press molding method of such parts.

For example, a press-formed product 41 having a hat cross-sectional shape as shown in FIG. 4A is drawn in a state where the end of the metal plate 19 is sandwiched between the wrinkle presser 37 and the die 35 by the press-molding die 31 shown in FIG. If it shape | molds, as shown in FIG.4 (b), a wall curvature will arise to the outer side (front side) rather than a target shape in the vertical wall part 45. FIG. This is an example of a shape freezing failure called a springback.
Further, the shape freezing failure due to the spring back in the drawing is increased as compared with the bending forming (foam forming) in which the forming is performed without using the wrinkle presser 37.

  As a method of reducing the vertical wall warpage to the outside (front side) of the press-formed product with a hat cross-sectional shape, bending is performed so that the portion corresponding to the vertical wall portion in the metal plate becomes convex outward during the forming ( (This kind of bending is called “reverse bending”), and then the reverse bending shape is bent back to the target shape, thereby applying tensile stress to the inside (back side) of the metal plate and compressive stress to the outside (front side). Examples thereof include a method of generating a bending moment opposite to the outward wall warp, and a method of increasing rigidity by imparting a shape such as a bead to the metal plate.

  In the press molding method disclosed in Patent Document 1, the rigidity is increased by forming a plurality of beads on the vertical wall portion of the hat channel member, and further, in the vertical wall between the beads by the action of the tensile tension between the beads. It is said that the spring back is reduced by changing the direction of the front and back residual stress of the metal plate.

  As shown in FIG. 6, the press molding method described in Patent Document 2 uses a molding die 91 including a punch 93, a die 95, and a movable die 99. A movable die 99 is provided on the inner wall of the die 95. Then, the movable die 99 is moved back upward (FIG. 6A), and molding by the punch 93 is started in a state where the plate material P is sandwiched between the die side wrinkle pressing portion 95c by the wrinkle pressing member 97 (FIG. 6). 6 (b)), and thereafter, the movable die 99 is advanced downward with the crease pressed, and the die edge portion is formed by the die shoulder portion (FIGS. 6 (c) to (d)). It is said to reduce bending and bending back by While the vertical wall portion and the die edge portion of the plate material P are being molded, a large tension is applied to the vertical wall portion as a result of the application of a wrinkle pressing load. FIG. 6 is a view corresponding to FIG. 1 of Patent Document 2, but for the convenience of explanation, the direction of the mold in the vertical direction is shown reversed.

Japanese Patent Laid-Open No. 2005-103613 JP 2000-271661 A

  In the press molding method disclosed in Patent Document 1, in order to form a plurality of beads on the vertical wall portion of the hat channel member, it is necessary to mold parts other than the target part shape, and the yield of the material is deteriorated. There is a problem.

  The press forming method disclosed in Patent Document 2 has no space between the punch top plate portion and the metal plate, and applies a large tension to the metal plate by the operation of the movable die. In a high-strength steel plate having a low ductility and a tensile strength of 980 MPa or more, there is a risk of fracture at the punch shoulder and the vertical wall. Further, since a large tension is applied, reverse bending does not occur in the vertical wall portion during the molding, and it is not possible to obtain a springback suppressing effect by bending back after generating the reverse bending described above.

  The present invention has been made in order to solve the above-mentioned problems, and even when a press-formed product having a hat cross-sectional shape is formed using a high-strength steel plate, a shape like a bead is imparted. It is an object of the present invention to provide a press molding die and a press molding method excellent in shape freezing property capable of greatly reducing springback.

  The present inventors have a mold release that causes a problem when a press-formed product 41 having a hat cross-sectional shape as shown in FIG. 4 is drawn using a press-molding die 31 having a conventional shape as shown in FIG. The means for suppressing the later springback was examined.

  As described above, in addition to the wall warp to the outside (front side) of the vertical wall portion 45 of the press-formed product 41, the spring back includes the opening of the top plate portion 43 and the vertical wall portion 45 at the wall warp and the connection portion 44. There is a mouth opening in which the angle increases and the opening of the press-formed product 41 opens (see FIG. 4B).

Wall warpage is caused by bending and bending back by the die shoulder 35a at a portion corresponding to the vertical wall 45 in the metal plate 19, and tensile stress on the front side (die 35 side) of the metal plate 19, and the back side of the metal plate 19 (punch). 33 side) is caused by a bending moment generated due to a difference in front and back stress between the front side and the back side at a portion corresponding to the vertical wall portion 45 in the metal plate 19.
When the bending moment is generated in the vertical wall portion 45, after the mold release, the vertical wall portion 45 is elastically deformed so that the bending moment becomes zero. As a result, the vertical wall portion 45 is warped.

  From the above, in order to suppress the wall warp, it is effective to narrow the range in which the metal plate 19 is bent and bent back by the die shoulder portion 35a in the forming process of the vertical wall portion 45 of the press-formed product 41. I found out.

On the other hand, in addition to the wall warp, the opening is the tensile stress and back side generated on the front side (die 35 side) of the connecting portion 44 where the punch shoulder 33b of the metal plate 19 abuts after the press-formed product 41 is released. This is due to the bending moment generated by the difference between the front and back stresses with the compressive stress generated on the punch 33 side.
When the bending moment is generated in the connecting portion 44, an elastic deformation occurs in which the opening angle of the top plate portion 43 and the vertical wall portion 45 increases after releasing, and as a result, a mouth opening occurs.

From the above, in order to suppress the elastic deformation in which the opening angle of the connecting portion 44 increases at the opening of the mouth, a bending moment opposite to the bending moment in the connecting portion 44 formed by contacting the punch shoulder portion 33b is set. It has been found that it is effective to generate the top plate portion 43.
The present invention has been made on the basis of such knowledge, and specifically has the following configuration.

(1) A press-molding die according to the present invention forms a press-molded product having a hat cross-sectional shape having a top plate portion, a vertical wall portion continuous from the top plate portion, and a flange portion continuous from the vertical wall portion. A punch having a top plate forming portion for forming the top plate portion and a vertical wall forming portion for forming the vertical wall portion, a top plate forming portion for forming the top plate portion, and the vertical wall A die having a vertical wall forming part for forming the part and a flange forming part for forming the flange part, and disposed at both sides of the punch and movable in the press forming direction, and at least the flange in cooperation with the die A wrinkle presser that molds the base end of the part, a plate presser that is outside the die and is disposed opposite to the press forming direction of the wrinkle presser and is movable with the wrinkle presser, and the plate Between the presser and the wrinkle presser It is characterized in that a clearance adjustment means for adjusting the molding direction of the gap.

(2) In the device according to (1), the gap adjusting means is configured to be capable of adjusting the gap to a thickness exceeding the plate thickness of the metal plate and not more than 6 times the plate thickness. To do.

(3) In the above (1) or (2), the distance between the punch-side end of the plate press and the punch-side end of the wrinkle press is 0 mm or more, and The width is equal to or less than the width of the flange portion.

(4) A press molding method according to the present invention uses a press molding die described in any of (1) to (3) above, and a top plate portion and a vertical wall portion continuous from the top plate portion. And forming a hat-shaped press-formed product having a flange portion continuous from the vertical wall portion, placing a metal plate on the top plate forming portion so as to straddle the punch, and the wrinkle presser, A first step in which both ends of the metal plate are inserted into a gap formed by a plate presser disposed on the die side at a distance exceeding the thickness of the metal plate so as to face the wrinkle presser. And with the both ends of the metal plate being inserted into the gap, the wrinkle presser and the plate presser are moved relative to the punch bottom dead center with the gap exceeding the plate thickness being opened. A gap between the wrinkle presser and the plate presser A third step of sandwiching both end portions of the metal plate with a plate thickness of less than or equal to the thickness of the metal plate, and moving the die relative to the bottom dead center of molding so that all or one of the top plate portion, the vertical wall portion, and the flange portion are moved. And a fourth step of forming the part.

(5) In the above (4), the metal plate is a steel plate having a tensile strength of 590 MPa class or higher.

  The present invention forms the top plate portion when forming a press-formed product having a hat cross section having a top plate portion, a vertical wall portion continuous from the top plate portion, and a flange portion continuous from the vertical wall portion. A punch having a top plate forming portion and a vertical wall forming portion for forming the vertical wall portion, a top plate forming portion for forming the top plate portion, a vertical wall forming portion for forming the vertical wall portion, and the flange portion A die having a flange forming part for forming the wrinkle, and a wrinkle presser which is disposed on both sides of the punch and is movable in the press forming direction, and which forms at least the base end of the flange part in cooperation with the die. A plate presser that is arranged opposite to the outer side of the wrinkle presser at a predetermined interval in the press molding direction and is movable with the wrinkle presser, and a gap in the press molding direction between the plate presser and the wrinkle presser is adjusted. And a gap adjusting means By using the press forming die, greatly reducing the spring back without imparting a shape such as beads, it is possible to mold the press-molded product having excellent hat cross-section in the shape freezing property.

It is explanatory drawing for demonstrating the press molding die and press molding method which concern on embodiment of this invention. It is explanatory drawing of the other example of the press molding die which concerns on embodiment of this invention. It is explanatory drawing of the press molded product made into the shaping | molding object in an Example. FIG. 3 is a perspective view of a press-formed product to be molded in the present invention and an explanatory diagram for explaining a spring back generated in the press-formed product. It is explanatory drawing of the press molding method using the press-molding die of the conventional shape. It is explanatory drawing explaining the press molding method of a prior art.

  A press mold 1 according to an embodiment of the present invention will be described with reference to FIG.

<Press mold>
The press molding die 1 has a punch 3, a die 5, a wrinkle presser 7, a plate presser 9, and a gap forming member 11 as a gap adjusting means.
Hereinafter, each structure of the press molding die 1 will be described.

≪Punch≫
The punch 3 connects the top plate forming portion 3a for forming the top plate portion 43 of the press-formed product 41, the vertical wall forming portion 3b for forming the vertical wall portion 45, and the top plate forming portion 3a and the vertical wall forming portion 3b. It has a punch shoulder 3c.

≪Die≫
The die 5 includes a top plate forming portion 5a for forming the top plate portion 43 of the press-formed product 41, a vertical wall forming portion 5b for forming the vertical wall portion 45, and a die shoulder portion 5c continuous with the vertical wall forming portion 5b. The flange forming portion 5d for forming the flange portion 47 is formed continuously to the die shoulder portion 5c.

≪Wrinkle presser≫
The wrinkle presser 7 is disposed so as to be able to support the back side (punch 3 side) of both end portions of the metal plate 19, and is movable in the direction in which the die 5 moves relative to the punch 3 side (press forming direction).
The end of the wrinkle presser 7 on the punch side is disposed close to the vertical wall forming portion 3 b of the punch 3.

≪Plate presser≫
The plate retainer 9 faces the wrinkle retainer 7 and is disposed so as to be able to come into contact with the front side (outside of the die 5) of both ends of the metal plate 19, and is movable together with the wrinkle retainer 7 in the press forming direction.

≪Gap forming member≫
The gap forming member 11 is formed such that a gap into which the end of the metal plate 19 can be inserted is formed between the wrinkle presser 7 and the plate presser 9 and the gap D of the gap can be adjusted.
(See FIG. 1 (a)).

  The gap D formed by the gap forming member 11 is preferably more than the plate thickness of the metal plate 19 and not more than 6 times the plate thickness.

  Further, the distance X between the end of the plate presser 9 on the punch 3 side and the end of the wrinkle presser 7 on the punch 3 side is 0 mm or more (see FIG. 1A), and the flange portion of the press-formed product 41 It is desirable that the width is 47 or less.

  In the above description, the gap adjusting member 11 is used as the gap adjusting means. However, as another example of the gap adjusting means, a position control mechanism for controlling the positions of the wrinkle presser 7 and the plate presser 9 is used. Etc., the gap D may be adjustable.

<Press molding method>
Next, the press molding method according to the present embodiment will be described below.
The press molding method according to the present embodiment is to mold a press molded product 41 having a hat cross-sectional shape as shown in FIG. 4A using a press molding die 1 as shown in FIG. First step of inserting both ends of the metal plate 19 into the gap between the wrinkle presser 7 and the plate presser 9 formed by using the gap adjusting means, and forming the wrinkle presser 7 and the plate presser 9 on the punch 3 side A second step of relative movement to the dead center, a third step of clamping both ends of the metal plate 19 by the wrinkle presser 7 and the plate presser 9, and the die 5 until the bottom dead center is formed with the both ends held And a fourth step of relative movement.
Hereafter, each said step is demonstrated based on FIG.

≪First process≫
In the first step, the metal plate 19 is disposed so as to face the top plate forming portion 3a so as to straddle the punch 3, and both ends of the metal plate 19 are wrinkle pressers formed using the gap forming member 11 as a gap adjusting means. 7 is a step of inserting into the gap between the plate holder 9 and the plate holder 9 (FIG. 1A).

≪Second process≫
In the second step, as shown in FIG. 1 (b), the wrinkle presser 7 and the plate presser 9 are relatively moved to the bottom dead center on the punch 3 side in a state where both ends of the metal plate 19 are inserted into the gap. It is a process to.
In the second step, the gap D between the wrinkle presser 7 and the plate presser 9 formed in the first step is kept constant, and both ends of the metal plate 19 are restrained by the wrinkle presser 7 and the plate presser 9. Without bending, the metal plate 19 is bent.

Although friction occurs between both end portions of the metal plate 19 and the surface that contacts the wrinkle presser 7 and the plate presser 9, the friction does not restrain movement of the both end portions. With the formation of 3a, the both end portions move to the punch 3 side.
Therefore, a deflection occurs in a portion corresponding to the top plate portion 43 in the metal plate 19 (see FIG. 1B).

≪Third process≫
In the third step, as shown in FIG. 1 (c), the gap forming member 11 is removed and the wrinkle presser 7 is moved relative to the plate presser 9 side, and both ends of the metal plate 19 are moved by the wrinkle presser 7 and the plate presser 9. Is a step of clamping.
In the third step, the portions at both ends of the metal plate 19 sandwiched between the wrinkle presser 7 and the plate presser 9 may be at least a part of the flange portion 47 of the press-formed product 41, or after release. The part removed by trimming may be used.

≪Fourth process≫
The fourth step is a step in which the die 5 is relatively moved to the molding bottom dead center, and the top plate portion 43, the vertical wall portion 45, and the flange portion 47 are all or partly molded.

<Reason why springback is suppressed>
The reason why both the wall warp and the mouth opening that occur after mold release can be simultaneously suppressed by the press molding method using the press molding die 1 according to the present embodiment will be described below.

≪About mouth opening≫
In the first step, both end portions of the metal plate 19 are inserted into the gap formed by the wrinkle presser 7 and the plate presser 9 that are arranged at a predetermined distance D, and in the second step, both end portions of the metal plate 19 are inserted into the gap. The wrinkle presser 7 and the plate presser 9 are moved relative to the punch 3 side to the bottom dead center for forming in the inserted state and the both ends are not restrained.

Thereby, as shown in FIG.1 (b), the convex deformation | transformation to the die | dye 5 side generate | occur | produces in the site | part corresponded to the top-plate part 43 in the metal plate 19. FIG.
Thereafter, through the third step and the fourth step, the portion where the deflection occurs is pressed by the top plate forming portion 5a of the die 5 and formed into the top plate portion 43, whereby the front side of the top plate portion 43 (die A compressive stress is applied to the (5 side) and a tensile stress is applied to the back side (the punch 3 side), resulting in a difference between the front and back stresses.

  Due to the difference between the front and back stresses in the top plate portion 43, a bending moment opposite to the bending moment generated in the connection portion 44 is generated in the top plate portion 43. As a result, the elastic deformation in which the opening angle of the top plate portion 43 and the vertical wall portion 45 increases after release is suppressed, and the opening of the press-formed product 41 is suppressed.

≪About wall warp≫
In the second step, the wrinkle presser 7 and the plate presser 9 are moved relative to each other while the both ends of the metal plate 19 are inserted into the gap formed by the wrinkle presser 7 and the plate presser 9 separated by a predetermined distance D. Since the tension applied to the plate 19 is reduced, cracking can be avoided and reverse bending occurs at a portion corresponding to the vertical wall portion 45 in the metal plate 19.

In the third step, both ends of the metal plate 19 are clamped by the wrinkle presser 7 and the plate presser 9, and when the vertical wall portion 45 is formed in the clamped state in the subsequent fourth step, the vertical bending occurs. The portion corresponding to the wall portion 45 is bent back.
Through this series of processes, tensile stress is applied to the back side (punch side) of the portion corresponding to the vertical wall portion 45, and compressive stress is applied to the front side (die side), so that the bending moment in the direction opposite to the wall warp to the front side is applied. And wall warpage is reduced.

  Further, the wrinkle presser 7 and the plate presser 9 are relatively moved in a state where both ends of the metal plate 19 are inserted into the gap formed by the wrinkle presser 7 and the plate presser 9 in the second step, and the wrinkle presser 7 in the third step. The both end portions are clamped by the plate press 9 and the vertical wall portion 45 is formed in the clamped state in the subsequent fourth step. As a result, compared with the conventional example in which the range of bending and bending back is substantially the entire vertical wall portion 45, the press molding method according to the present invention reduces the range to only the lower portion of the vertical wall portion 45. It is possible to reduce wall warpage after mold release.

  In the press molding method according to the present embodiment, when the predetermined distance D of the gap formed by the wrinkle presser 7 and the plate presser 9 is increased, the deflection of the portion corresponding to the top plate portion 43 in the metal plate 19 in the second step. Increases, and the bending moment in the direction opposite to the bending moment at the connecting portion 44 is increased, and as a result, the opening of the mouth can be further reduced.

  However, if the deflection of the part becomes excessive, the compressive stress generated in the part becomes too large, and the press-formed product 41 cannot be made into a target shape. Therefore, it is desirable that the predetermined distance D of the gap is not more than 6 times the plate thickness of the metal plate 19.

  Further, an interval X (see FIG. 1A) between the end of the plate retainer 9 on the punch 3 side and the end of the wrinkle retainer 7 on the punch 3 side is determined from the flange width A of the flange portion 47 of the press-formed product 41. If it is increased, the end of the metal plate 19 may slip through the plate retainer 9 in the second step. In this case, the end of the metal plate 19 is inserted into the gap and the wrinkle retainer 7 and the plate are inserted. The presser 9 cannot be moved relatively.

  Therefore, the distance X between the end of the plate retainer 9 on the punch 3 side and the end of the wrinkle retainer 7 on the punch 3 side is 0 mm or more and the width A of the flange portion 47 of the press-formed product 41 or less. Is desirable.

Note that the press molding die 21 having the interval X in the vicinity of 0 mm is for molding a press molded product (not shown) having a hat cross-sectional shape with an inclined vertical wall as shown in FIG.
The press molding die 21 has a sharp die shoulder portion 25c, the flange portion of the press-molded product is molded by the wrinkle presser 7 and the plate presser 9, and the base end of the flange portion is formed by the die shoulder portion 25c. The wrinkle presser 7 is molded in cooperation.

  Furthermore, the press forming method according to the present embodiment more effectively suppresses the spring back after the release of the press-formed product 41 even when a steel plate having a tensile strength of 590 MPa or higher is used as the metal plate 19. Is possible.

  In order to confirm the effects of the press molding die 1 and the press molding method according to the present invention, press molding analysis and springback analysis by the finite element method (FEM) were performed, and the results will be described below.

  In this embodiment, the press formed product 51 having the hat cross section shown in FIG. 3A is formed by the wrinkle presser 7 and the plate presser 9 for the case of forming using the press mold 1 shown in FIG. The distance D between the gaps and the distance X between the ends of the punch 3 side of the wrinkle presser 7 and the plate presser 9 are subjected to press forming analysis, and the press-formed product 51 formed up to the bottom dead center after the release is released. Springback analysis was performed.

As shown in FIG. 3, the dimensions of the press-formed product 51 are as follows. The flange width of the flange portion 57 is A = 30 mm, the length in the longitudinal direction is L = 250 mm, the molding height is Z = 80 mm, the vertical wall angle (connection portion The opening angle of the top plate portion 53 and the vertical wall portion 55 centering on 54 is θ = 10 °.
The metal plate 19 used for forming the press-formed product 51 was made of two types of steel plates (tensile strength 590 MPa class, 1470 MPa class) having a plate thickness t = 1.4 mm and different tensile strengths.

The distance D between the gaps formed by the wrinkle presser 7 and the plate presser 9 exceeds the plate thickness of the metal plate 19 and is not more than 6 times the plate thickness (D = 1.41 mm to 8.4 mm).
An interval X between the punch 3 side end of the wrinkle presser 7 and the punch 3 side end of the plate presser 9 is set to X = 10, 30 mm, and is equal to or less than the flange width A of the flange portion 57 of the press-formed product 51.

In the press forming analysis, a press formed product 51 was formed on the metal plate 19 having the above specifications by a press forming method using the press forming die 1 according to the present invention shown in FIG.
Based on the spring back analysis, the spring back of the press-formed product 51 was evaluated by wall warp ρ [mm ⁻¹ ], opening amount ΔW [mm], and crack.

The wall warp ρ [mm ⁻¹ ] is a curvature calculated from the coordinates of three points located at 30 mm, 40 mm, and 50 mm along the press molding direction from the top plate portion 53 in the vertical wall portion 55 of the press molded product 51. did.
The opening amount ΔW [mm] was a distance between two points located 60 mm from the top plate portion 53 along the press molding direction in the vertical wall portions 55 located on both sides of the top plate portion 53.
Cracking was evaluated as cracking not occurring (◯) when cracking did not occur after press molding, and cracking (x) when cracking occurred.
Table 1 summarizes the press molding conditions and evaluation results.

In Table 1, No. 1 and No. 11 are the results of using a conventional drawing method (conventional example), and No. 2 to No. 9 and No. 12 to No. 19 are press moldings according to the present invention. It is the result of using a method (invention example).
Compared with the conventional example, the example of the present invention was clearly good in that the wall warp ρ and the opening amount ΔW were reduced.

  When the distance X between the end portions of the punch 3 side of the wrinkle presser 7 and the plate presser 9 on the gap D formed by the wrinkle presser 7 and the plate presser 9 is considered to have an effect on the opening amount ΔW (No. 2). -3, No. 4-6, No. 7-9, No. 12-13, No. 14-16, No. 17-19), the die shoulder 5c in the metal plate 19 as the spacing X increases. Since the range subjected to bending and bending back due to is narrowed, both the wall warp ρ and the opening amount ΔW were reduced.

  Further, when the effect of the distance D on the opening amount ΔW is observed in each of the distances X of the end portions on the punch 3 side of the wrinkle presser 7 and the plate presser 9 (No. 4, 7, No. 2, 5, 8, No.3,6.9, No.14,17, No.12,15,18, No.13,16,19), the top plate of the metal plate 19 in the second step as the distance D increases. The deflection corresponding to the portion 53 increased, the difference between the front and back stresses generated at the bottom dead center of the molding increased, and the opening amount ΔW decreased.

  When a steel plate with a tensile strength of 590 MPa is used (No. 1 to 9), the distance D between the wrinkle retainer 7 and the plate retainer 9 is 4.2 mm, and the distance between the wrinkle retainer 7 and the end 3 of the plate retainer 9 on the punch 3 side. It was shown that the wall warp ρ and the opening amount ΔW can be sufficiently reduced by setting X to about 10 mm.

  On the other hand, when a steel plate having a tensile strength of 1470 MPa is used (No. 11 to 19), the distance D between the wrinkle presser 7 and the plate presser 9 is 7.0 mm, and the punch 3 side end portion of the wrinkle presser 7 and the plate presser 9 is used. It was shown that the wall warp ρ and the opening amount ΔW can be sufficiently reduced by setting the distance X to about 10 mm.

  From the above, it is possible to greatly reduce the springback by forming a press-formed product having a hat cross-sectional shape using the press-forming method or press-molding die according to the present invention, and to produce a press-formed product having excellent shape freezing property. Proven.

DESCRIPTION OF SYMBOLS 1 Press molding die 3 Punch 3a Top plate molding part 3b Vertical wall molding part 3c Punch shoulder part 5 Die 5a Top plate molding part 5b Vertical wall molding part 5c Die shoulder part 5d Flange molding part 7 Wrinkle presser 9 Plate presser 11 Gap formation Member 19 Metal plate 21 Press molding die 23 Punch 23a Top plate forming portion 23b Vertical wall forming portion 23c Punch shoulder portion 25 Die 25a Top plate forming portion 25b Vertical wall forming portion 25c Die shoulder portion 31 Press forming die 33 Punch 33a Top Plate forming portion 33b Punch shoulder portion 35 Die 35a Die shoulder portion 37 Wrinkle presser 41 Press molded product 43 Top plate portion 44 Connection portion 45 Vertical wall portion 47 Flange portion 51 Press molded product 53 Top plate portion 54 Connection portion 55 Vertical wall portion 57 Flange part 91 Mold 93 Punch 95 Die 95c Die side wrinkle holding part 97 Wrinkle holding 99 Movable die

Claims (5)

A press mold for molding a top cross-section, a vertical wall portion continuous from the top plate portion, and a hat-shaped press-formed product having a flange portion continuous from the vertical wall portion,
A punch having a top plate forming portion for forming the top plate portion and a vertical wall forming portion for forming the vertical wall portion;
A die having a top plate forming portion for forming the top plate portion, a vertical wall forming portion for forming the vertical wall portion, and a flange forming portion for forming the flange portion;
A wrinkle presser that is arranged on both sides of the punch and is movable in the press molding direction and that forms at least the proximal end of the flange portion in cooperation with the die;
A plate press that is outside the die and is disposed opposite to the press forming direction of the wrinkle presser at a predetermined interval and is movable together with the wrinkle presser,
A press molding die comprising a gap adjusting means for adjusting a gap in the press molding direction between the plate press and the wrinkle press.   2. The press-molding die according to claim 1, wherein the gap adjusting means is configured to be capable of adjusting the gap to a thickness exceeding the plate thickness of the metal plate and not more than 6 times the plate thickness.   The distance between the punch-side end of the plate press and the punch-side end of the wrinkle press is 0 mm or more and less than the width of the flange portion of the press-formed product. 2. A press mold according to 1. A hat cross section having a top plate portion, a vertical wall portion continuous from the top plate portion, and a flange portion continuous from the vertical wall portion using the press-molding die according to any one of claims 1 to 3. A press molding method for molding a press-formed product having a shape,
Place the metal plate on the top plate forming part so as to straddle the punch,
Both ends of the metal plate are inserted into a gap formed by the wrinkle presser and a plate presser disposed on the die side at a distance exceeding the plate thickness of the metal plate so as to face the wrinkle presser And the first step
A second step of moving the wrinkle presser and the plate presser relative to the punch bottom dead center with the gap exceeding the plate thickness in a state where both ends of the metal plate are inserted in the gap; ,
A third step of sandwiching both ends of the metal plate by setting the gap between the wrinkle presser and the plate press to be equal to or less than the plate thickness of the metal plate;
And a fourth step of forming all or part of the top plate portion, the vertical wall portion, and the flange portion by relatively moving the die to a forming bottom dead center.   The press forming method according to claim 4, wherein the metal plate is a steel plate having a tensile strength of 590 MPa class or higher.