JP2006320941A - Pressing method and press die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a press die, which has such a simple structure as composed only by increasing cam drivers, and which prevents spring back and forms a highly precise pressed product having a hat-like cross section, during one press stroke, and to provide a pressing method using it. <P>SOLUTION: A hanging cam body 25, which holds a bending edge 21, is provided with: a projected part sliding surface 251, which is brought into contact with an inclined sliding surface 41 of a first cam driver 40 provided on a lower die 11 and slides thereon; and a recessed part sliding surface 253, which is brought into contact with an inclined sliding surface 51 of a second cam driver 50 provided on the lower die 11, and whose angle θ2 to a perpendicular line is larger than an angle θ1 thereto of the projected part sliding surface 251. Thus, a corner part 211 of the bending edge 21 presses approximately the same position as the vicinity of a bending expected position 71 of a metal plate stock 70 from the start of the pressing till the completion thereof. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a press method and a press die used for the press method, and more particularly to a press method for preventing the occurrence of so-called spring back of a press product after press molding and a press die used for the press method.

A hat-shaped cross-section frame installed in the front-rear direction on the left and right of the lower surface of an automobile floor panel requires sufficient strength to support the engine, suspension, etc. A high-strength steel plate material called a high-tensile material that is thin but has high strength has been used.
When a frame having a hat-shaped cross section is bent and formed with a normal steel plate material, warpage occurs in the vertical wall of the hat-shaped cross section due to an angle change due to residual stress in the bending shoulder and bending bending return generated during forming.
The angle change and the vertical wall warp are combined to open a wall on the opening side of the hat-shaped cross section, that is, to generate a springback.
However, when the high-tensile steel plate material is bent as described above, the amount of spring back is further increased, making it difficult to obtain high forming accuracy.

As a method of preventing the angle change failure of the bent portion, (1) a method of designing the shape of the molding die so as to be an exact size in a spring-backed state, and (2) a molding bending direction along the ridge line of the bent portion There have been proposed a method of forming a reverse bending radius portion in the reverse direction, and (3) a method of applying a compressive stress in the thickness direction of the bending portion to reduce the residual stress. 3 paragraph (0005)).
As countermeasures against this, JP-A-8-1243 (hereinafter referred to as “Patent Document 1”), JP-A-2002-66638 (hereinafter referred to as “Patent Document 2”), and JP-A-2003-2003. No. 103306 (hereinafter referred to as “Patent Document 3”) and the like have been proposed.
JP-A-8-1243 JP 2002-66638 A JP 2003-103306 A

  However, in the “press mold apparatus” of Patent Document 1, a corner portion of the convex portion 3 provided on the lower die 2 and a pad 7 provided on the upper die 6 and having a concave surface 8 along the convex portion 3 on the lower surface. After the sheet metal material is roughly bent, the bending blade 12 is advanced from the side to simultaneously mold the side wall and the flange portion. According to this, the pad 7 is formed in the vicinity of the corner of the convex portion 3 during the rough bending. There is a problem that a reverse bending line is generated at the lower end, which remains until the end and affects the accuracy of the hat-shaped cross section.

  Further, in the “pressing method and press auxiliary die of a metal plate with a small spring back” in Patent Document 2, a bending auxiliary die 30 is disposed between the metal plate 1 on the punch 13 and the die 22 and the die 22 is lowered. The flange 30a, 30b of the auxiliary mold 30 is bent by the connecting pin 30c, and the metal plate 1 is bent. However, a complicated facility called the auxiliary mold 30 is required, the equipment cost is high, and maintenance of the auxiliary mold is also performed. It was not easy to put it to practical use because it was necessary.

  Furthermore, the “metal plate bending method and molding die used for the forming method” disclosed in Patent Document 3 is an arch that uses a metal plate bent as a fulcrum in order to reduce defective shape change of a molded member. The angle formed by the lateral flat forming portion and the inclined flat portion of the forming die is adjusted so that the arch portion has a period in which the inclined flat forming portion of the forming punch and the inclined flat portion of the forming die are simultaneously in contact with each other. Although the obtuse angle is used, according to this, it is necessary to set the angle according to the material and thickness of the metal plate, which limits the degree of freedom in designing the product and the molding die.

  Therefore, in order to solve such problems, the present invention forms a press product having a precise hat-shaped cross section by preventing a springback during one press stroke with a simple configuration in which only a cam driver is added. An object of the present invention is to provide a press method and a press die that can be used.

  In the pressing method according to the first aspect of the present invention, the center portion in the width direction of the flat metal plate material is sandwiched in the vertical direction by a pad and a punch having a stepped portion projecting outward from the recessed corner portion of the lower side surface. Then, the metal plate material is pressed against the side surface of the punch while pressing and bending both sides in the width direction downward with a die, and the metal plate material is formed into a hat-shaped cross section consisting of a bottom portion, a vertical wall portion, and a flange portion. In the pressing method for forming the metal plate material, the corner portion of the die is brought into contact with the assumed bending position of the vertical wall portion and the flange portion of the metal plate material and lowered, and the metal plate material is moved to the locus of the assumed bending position. A first step of bending along the width direction, and both sides or side ends in the width direction of the metal plate material abut on the punch, and then the corner of the die is advanced toward the concave corner of the punch, and the metal plate The flange part is formed on the material. Characterized by comprising the steps, a.

Therefore, since the corner of the die bends the assumed bending position of the vertical wall and flange of the metal plate material almost along the trajectory, the corner of the die slides and moves along the vertical wall of the metal plate material. This reduces the amount to be bent and does not cause bending and bending back of the vertical wall portion of the metal plate material.
In addition, after both side portions or side end portions in the width direction of the metal plate material contact the punch, the corner portion of the die is advanced toward the concave corner portion of the punch to form a flange portion in the metal plate material. A slight compressive stress is applied to the vertical wall portion of the metal plate material, and it is possible to perform press forming while preventing the occurrence of spring back during one press stroke.

  The pressing method according to a second aspect of the present invention is the pressing method according to the first aspect, wherein in the first step, the metal plate material is directed to the punch until the metal plate material contacts the step of the punch. The entry angle of the die is θ1, and in the second step, the entry angle of the die toward the punch after the metal plate material contacts the stepped portion of the punch is θ2, and θ1 ≦ θ2. The die is shaped while changing the approach angle of the die toward the punch in two or more stages.

Therefore, until the metal plate material comes into contact with the stepped portion of the punch, it is possible to press a position as close as possible to the locus of the assumed bending position where the corner portion of the die contacts, so that the corner portion of the die is against the metal plate material. It can be molded with almost no slip, and the generation of internal stress can be suppressed.
After the metal plate material comes into contact with the step of the punch, the die enters at an angle closer to the horizontal than the previous trajectory, so the pressing force toward the side of the punch increases, and the spring of the metal plate material after forming The occurrence of back can be suppressed.

A pressing method according to a third aspect of the present invention is the pressing method according to the second aspect, wherein the die entrance angle is set in two stages of θ1 = 0 ° to 40 ° and θ2 = 40 ° to 90 °. It is characterized by that.
Therefore, only two types of cam drivers for moving the die are required, and the structure of the press die can be simplified.

A press die according to a fourth aspect of the present invention is a press die for realizing the press method according to the first to third aspects.
Therefore, since the press die is capable of changing the angle of entry of the die toward the punch into two or more stages, it is possible to provide a press die that can suppress the occurrence of springback of the metal material after forming.

  The press die according to claim 5 of the present invention is fixed to the lower die, and includes a top portion that supports the central portion in the width direction of the flat plate-shaped metal plate material from below, and a concave corner portion at a lower side surface that continues from the top portion. A punch having a stepped portion projecting outward; a pad supported by the upper die; and a pad for pressing the central portion in the width direction of the metal plate material against the punch from above; an inclined slide fixed to the lower die and facing the punch A cam driver having a moving surface, and the metal plate material is bent by sliding down on the inclined sliding surface of the cam driver and contacting both sides in the width direction of the metal plate material by descending the cam driver having a moving surface; A die that presses both sides in the width direction of the plate material against the side surface of the punch to form a predetermined shape, wherein the cam driver has an angle of the inclined sliding surface upright A first cam driver and the tilt The moving surface is composed of a second cam driver that is more inclined than the first cam driver, and the die abuts against the metal plate material at a corner and presses the metal plate material against the side surface of the punch A bending blade that is slidable in a direction intersecting the pressing direction on the upper surface, and is slidably contacted with the first cam driver by descending, and the bending blade follows the bending locus of the metal plate material. The metal plate material is moved toward the side surface of the punch, and after the metal plate material abuts on the step portion of the punch, the metal blade material is further slidably contacted with the second cam driver, and the bending blade is moved to the step. And a suspension cam body that is further moved toward the recessed corner portion of the portion.

Therefore, the position where the corners of the bending blade of the die abut on both sides in the width direction of the metal plate material can be made substantially constant along the bending trajectory of the metal plate material, and the die can be kept at this constant position. Since the pressing is performed, the die does not squeeze the metal plate material, and it is possible to suppress the occurrence of bending and bending back of the metal plate material.
Therefore, no warp is generated in the vertical wall portion of the product, and after the metal plate material comes into contact with the step portion of the punch, the die is pressed substantially at right angles to the bending angle of the metal plate material. Since it moves toward the concave corner, the pressing of the vertical wall portion of the metal plate material to the punch and the pressing to the concave corner portion by the die are performed almost simultaneously, and compressive stress is applied to both side walls of the metal plate material. It is possible to perform press molding while preventing the occurrence of springback during one press stroke.

  The press die according to a sixth aspect of the present invention is the press die according to the fifth aspect, wherein the first cam driver and the second cam driver are in a side view of the die in the moving direction. Arranged at overlapping positions, alternately arranged in a comb blade shape in a direction parallel to the moving direction of the die, and a sliding surface provided on the lower surface of the suspension cam body is the first cam driver The second cam driver is provided at a position corresponding to each inclined sliding surface.

  Therefore, the first and second cam drivers are alternately arranged in a comb blade shape in a direction parallel to the moving direction of the die at a predetermined interval, and the sliding surface of the suspension cam body is also the first and second cams. Since it is provided at a position corresponding to the driver, the size in the direction parallel to the moving direction of the press die can be reduced, and a compact press die can be obtained.

  According to the present invention, at least the first cam driver and the second cam are arranged so that the corner of the die contacts and presses against the assumed bending position of the vertical wall portion and the flange portion of the metal plate material. Since the cam driver changes the pressing angle and moves it, the pressing position on both sides of the metal plate material in the width direction hardly changes, and therefore slipping occurs between the width direction both sides of the metal plate material and the corners of the die. Therefore, the metal plate material is not bent and bent back, no internal stress remains, and the occurrence of a spring pack can be prevented.

Next, an embodiment of a press method and a press die according to the present invention will be described with reference to the drawings. The press method and press die of this embodiment are applied to press forming of a frame having a hat-shaped cross section of an automobile.
Here, FIG. 1 is a view showing a side cross-section of the press die, and FIG. 2 is a view taken in the direction of arrow A in FIG. 3 to 6 are side sectional views showing the operation of the press die.

The configuration of the press die will be described. As shown in FIG. 1, the press die 10 includes a lower die 11 and an upper die 13 that is attached to a bolster of a press machine and moves up and down.
The lower mold 11 is fixed with a punch 111 that supports the central portion in the width direction of the flat metal plate material 70 from below and a cam driver 30 having an inclined sliding surface that faces the side surface of the punch 111. Yes.
A pad 131 that presses the center in the width direction of the metal plate material 70 against the punch 111 from above and a die 20 described later are brought into sliding contact with the inclined sliding surface of the cam driver 30 by lowering. A cam slider 133 that is moved toward the side surface of the punch 111 is fixed.
On the lower surface of the cam slider 133, a slide holding surface 1331 formed with an inclined surface facing the punch 111 is provided.
The pad 131 and the cam slider 133 can be controlled to move up and down individually with respect to the upper mold 13.

The punch 111 has a top portion 1111, a side surface 1113 continuous from the top portion 1111, and a step portion 1115 projecting outward from a recessed corner portion 1117 below the side surface 1113.
The cam driver 30 includes an angle of a first cam driver 40 in which an inclined sliding surface 41 facing the side surface 1113 of the punch 111 is formed at an upright angle, and an inclined sliding surface 51 facing the side surface 1113 of the punch 111. Has a second cam driver 50 formed at an inclined angle with respect to the inclined sliding surface 41 of the first cam driver 40.

  The die 20 is brought into contact with the metal plate material 70 at a corner 211 at the tip, and a bending blade 21 that presses the metal plate material 70 against the side surface 1113 of the punch 111 and a cam slider 133 provided on the upper mold 13. The punch 111 is supported on the upper surface so as to be slidable in a direction intersecting the press direction, and is brought into sliding contact with the first cam driver 40 by descending so that the bending blade 21 follows the bending locus of the metal plate material 70. And the metal plate material 70 comes into contact with the step 1115 of the punch 111 and then slides against the second cam driver 50 by further lowering the bending blade 21. The suspension cam body 25 is further moved toward the recessed corner portion 1117 of the step portion 1115.

  The bending blade 21 is substantially square when viewed from the side of the moving direction of the die 20 and is removably attached to the tip of the suspension cam body 25 closest to the punch 111. Therefore, when forming a press product having a different cross-sectional shape or planar shape, the suspension cam body 25 can be used as it is, and only the bending blade 21 can be replaced with one formed to match the press shape. It has become.

The suspension cam body 25 has a suspension sliding surface 255 on the upper surface thereof, and is slidably supported on the slide holding surface 1331 of the cam slider 133.
The suspension cam body 25 is formed at a substantially right angle with respect to the slide holding surface 1331, and a convex sliding surface 251 that slides in contact with the inclined sliding surface 41 of the first cam driver 40. It is a substantially pentagonal shape formed with a concave sliding surface 253 that slides in contact with the inclined sliding surface 51 of the second cam driver 50 on the substantially lower surface of the suspension cam body 25.
Connected between the suspension cam body 25 and the cam slider 133 is pull-back means 1335 that always returns the suspension cam body 25 to the initial position when the cam slider 133 is raised.

The first cam driver 40 and the second cam driver 50 are arranged at positions overlapping in the moving direction side view of the die 20, and in a direction parallel to the moving direction of the die 20, FIG. As shown in FIG. 2, they are alternately arranged in a comb blade shape.
Further, the convex sliding surface 251 and the concave sliding surface 253 provided on the lower surface of the suspension cam body 25 are inclined sliding surfaces 41 of the first cam driver 40 and the second cam driver 50, respectively. , 51 is provided at a position corresponding to.

The inclined sliding surface 41 of the first cam driver 40 and the inclined sliding surface 251 of the suspension cam body 25 are bent at the first bending position of the metal plate material 70 as shown in FIGS. It is the same as the inclination of the arrow (b) connecting the assumed position 71 and the assumed bending position 71 at the second bending position, and the angle formed with the perpendicular is the approach angle θ1 of the die 20.
Similarly, the inclined sliding surface 51 of the second cam driver 50 and the inclination of the recessed portion sliding surface 253 of the suspension cam body 25 connect the assumed bending position 71 at the second bending position and the recessed corner portion 1117 of the punch 111. It is the same as the inclination of the arrow (c), and the angle formed with the perpendicular is the approach angle θ2 of the die 20. It is desirable that θ1 ≦ θ2.

It should be noted that the inclination of the slide holding surface 1331 of the cam slider 133 and the suspension sliding surface 255 of the suspension cam body 25 with respect to the pressing direction may be determined by the entry speed of the die 20.
The assumed bending position 71 is a position assuming that both side portions in the width direction of the metal plate material 70 are bent corner portions 1117 of the punch 111 and are bent into the vertical wall portion 75 and the flange portion 77.

7, 8, and 10 indicate that the corner portion 211 of the bending blade 21 of the die 20 comes into contact with the assumed bending position 71 of the metal plate material 70 at the initial stage of the press work, and the suspension cam body 25 is The figure shows a substantially vertical direction in which the upper die 13 descends while being suspended from the cam slider 133 and moves to the first bending position of the metal plate material 70.
The arrow (b) indicates that the die 20 is brought into sliding contact with the inclined sliding surface 41 of the first cam driver 40 while the convex sliding surface 251 of the hanging cam body 25 is in sliding contact with the further lowering of the upper mold 13. The suspending sliding surface 255 slides on the slide holding surface 1331 of the cam slider 133 to connect the assumed bending position 71 when the metal plate material 70 moves from the first bending position to the second bending position with a straight line. The direction and the angle with the perpendicular is the approach angle θ1 of the die 20, and θ1 = 0 ° to 40 ° is desirable.

  The arrow (C) indicates that the die 20 is brought into sliding contact with the inclined sliding surface 51 of the second cam driver 50 when the concave sliding surface 253 of the hanging cam body 25 is slid by the further lowering of the upper mold 13. Assuming bending at the second bending position when the hanging sliding surface 255 slides on the slide holding surface 1331 of the cam slider 133 and moves from the second bending position of the metal plate material 70 to the recessed corner portion 1117 of the punch 111. A direction roughly connecting the position 71 and the recessed corner portion 1117 is shown, and an angle with the perpendicular is an entrance angle θ2 of the die 20, and θ2 = 40 ° to 90 ° is desirable.

Therefore, the pressing direction of the arrow (c) at the second bending position of the metal plate material 70 is an obtuse angle with respect to the plate surface of the metal plate material 70 as shown in FIG. The pressure acts by dividing into an arrow (f) perpendicular to the plate surface and an arrow (g) in the plate surface direction. The component force of this arrow (g) acts as a force for compressing the metal plate material 70 in the plate surface direction. Therefore, a compressive stress remains on the metal plate material 70 to prevent spring back.
Note that arrows (d) and (e) indicate bending trajectories of the side end portion 73 of the metal plate material 70.

A pressing method in which the flat metal plate material 70 is pressed into a vehicle frame having a hat-shaped cross section by using the press die 10 configured as described above will be described.
First, the central portion in the width direction of the metal plate material 70 is placed on the top of the punch 111 while the upper die 13 is raised and the pad 131, the cam slider 133, and the die 20 suspended by the cam slider 133 are also raised. Then, the upper die 13 is lowered vertically and the metal plate material 70 is pressed against the punch 111 from above by the pad 131 (not shown).

In this state, the upper die 13 is further lowered, and the corner portion 211 of the bending blade 21 provided at the tip of the die 20 is brought into contact with the vicinity of the assumed bending position 71 of the metal plate material 70 (FIG. 3). reference).
At this time, the convex sliding surface 251 of the suspension cam body 25 is not yet in contact with the inclined sliding surface 41 of the first cam driver 40, and the concave sliding surface 253 of the suspension cam body 25 is the first 2 is not in contact with the inclined sliding surface 51 of the cam driver 50.

When the upper die 13 is further lowered vertically, the corner portion 211 of the bending blade 21 vertically presses the vicinity of the assumed bending position 71 of the metal plate material 70 as shown by arrows (A) in FIGS. Then, the metal plate material 70 is bent to a first bending position indicated by a one-dot chain line.
When the metal plate material 70 is bent to the first bending position, the convex sliding surface 251 of the suspension cam body 25 is inclined by the first cam driver 40 as shown in FIG. Contact with the sliding surface 41 is started, and while the convex sliding surface 251 slides on the inclined sliding surface 41, the suspension cam body 25 and the die 20 are moved toward the punch 111 as shown by arrows ( B), the metal plate material 70 is bent.

7 and 8, since the arrow (b) that is the movement locus of the die 20 is a straight line with respect to the substantially arcuate locus of the assumed bending position 71 indicated by the dotted line in FIG. 7 and FIG. Deviation occurs without moving on the trajectory of the assumed position 71, which causes the die 20 to slide on the metal plate material 70, but the amount of deviation is slight and does not cause internal stress. .
In order to reduce the amount of deviation as much as possible, the cam drivers 40 and 50 may be increased and the approach angle of the die 20 may be set in multiple stages as shown in FIG.

Then, the metal plate material 70 has a position where both side portions in the width direction of the metal plate material 70 are in contact with the stepped portion 1115 of the punch 111 (FIG. 7), or a side end portion 73 of the metal plate material 70 has the punch 111. When it is bent to the second bending position at the position abutting on the stepped portion 1115 (FIG. 8), the lower slide of the upper mold 13 causes the concave sliding surface 253 of the suspension cam body 25 to move as shown in FIG. The second cam driver 50 comes into contact with the inclined sliding surface 51 and the concave sliding surface 253 slides on the inclined sliding surface 51 while the suspension cam body 25 and the die 20 are moved toward the punch 111, as shown in FIG. The metal plate material 70 is bent by moving in the direction of the arrow (c) in FIG.
When the concave sliding surface 253 slides on the inclined sliding surface 51, the convex sliding surface 251 of the suspension cam body 25 is separated from the inclined sliding surface 41 of the first cam driver 40.

  Further, when the upper die 13 is lowered, the assumed bending position 71 of the metal plate material 70 is pressed toward the concave corner portion 1117 of the punch 111 by the corner portion 251 of the bending blade 21, and both side portions of the metal plate material 70 in the width direction are pressed. As shown in FIG. 6, the punch 111 is bent in an S shape as shown in FIG. 6 while sliding at the corner of the step 1115 of the punch 111 or sliding the side end 73 of the metal plate material 70 on the step 1115 of the punch 111.

Eventually, as shown in FIG. 1, the corner 211 of the bending blade 21 comes into contact with the concave corner 1117 of the punch 111 with the metal plate material 70 sandwiched therebetween, and the vertical wall surface 2113 of the bending blade 21 contacts the side surface 1113 of the punch 111. Abutting with the plate material 70 in between.
As a result, the metal plate material 70 is firmly pressed against the side surface 1113 and the step portion 1115 of the punch 111 to be molded, and the press molding is completed.

When the upper die 13 is raised after the molding is finished and the pressing force to the die 20 by the cam slider 133 is released, the suspension cam body 25 is moved along the slide holding surface 1331 of the cam slider 133 in the opposite direction by the pull-back means 1335. The bending blade 21 moves upward while moving away from the punch 111.
When the upper die 13 is further raised and the pad 131 is separated from the punch 111, the press-formed metal plate material 70 can be released from the punch 111, and the metal plate material 70 formed in the frame is removed from the press die 10. And the pressing process is completed.
When the bending blade 21 is raised, the concave sliding surface 253 of the suspension cam body 25 is guided while abutting against the inclined sliding surface 51 of the second cam driver 50 and moves to the right in the figure. Alternatively, the concave sliding surface 253 of the suspension cam body 25 may be set to rise without coming into contact with the inclined sliding surface 51 of the second cam driver 50.

  As described above, according to the press die of the present embodiment and the press method using the press die, the corner portion 211 of the bending blade 21 has substantially the same position in the vicinity of the assumed bending position 71 of the metal plate material 70. Then, the suspension cam body 25 holding the bending blade 21 is brought into contact with the inclined sliding surface 41 of the first cam driver 40 provided in the lower die 11 so as to press from the initial stage of press working to the completion of molding. The sliding surface 251 that slides and the inclined sliding surface 51 of the second cam driver 50 provided on the lower mold 11, and the concave sliding surface that is in a sloping manner from the angle of the convex sliding surface 251. 253 is provided, so that bending back by the bending blade 21 does not act on the metal plate material 70 being formed, and therefore, a hat-shaped press product with less spring back can be formed at low cost. .

In addition, this invention is not limited to the thing of the said embodiment, A various change is possible in the range which does not deviate from the meaning.
For example, in the above-described embodiment, an example of forming a press product having a hat-shaped cross section has been described. However, the present invention is not limited to this, and can be applied to a press product having a U-shaped or U-shaped cross section. In this case, the pressing position by the corner of the bending blade of the metal plate material corresponding to the above assumed bending position may be set assuming one point.

  In the embodiment, the two cam drivers having inclined sliding surfaces with different angles and the angle corresponding to the inclined sliding surface so that the pressing position of the material follows the bending locus of the metal plate material. Although the suspension cam body having two sliding surfaces is set, the die from the first bending position to the second bending position is increased as shown in the example of FIG. 10 by increasing the number of combinations of the cam driver and the suspension cam body. The trajectory may be changed in a plurality of stages and moved.

  In the pressing method of the present invention, the center portion in the width direction of the flat metal plate material is sandwiched in the vertical direction by a pad and a punch having a step portion projecting outward from the concave corner portion of the lower side surface, and the metal plate material In the pressing method of pressing both sides of the width direction downward with a die and pressing the side of the punch while bending it to form the metal plate material into a hat-shaped cross-section part consisting of a bottom part, a vertical wall part and a flange part, A first step of lowering the corner portion of the die in contact with the assumed bending position of the vertical wall portion and the flange portion of the metal plate material and bending the metal plate material along the locus of the assumed bending position; Then, after both side portions or side end portions in the width direction of the metal plate material abut on the punch, the corner portion of the die is advanced toward the concave corner portion of the punch, and a flange portion is formed in the metal plate material. A second step; Since the pressing position of the metal plate material by the corner portion of the die does not deviate greatly with respect to the metal plate material, the die corner portion can be formed without sliding on the metal plate material. The material is not bent and bent back, and the occurrence of springback can be prevented.

  The press die of the present invention is fixed to the lower die, and has a top portion that supports the central portion in the width direction of the flat metal plate material from below, and a step projecting outward from the concave corner portion of the lower side portion continuous from the top portion. A punch that has a portion, a pad that is supported by the upper die, presses the central portion in the width direction of the metal plate material against the punch from above, and a cam that is fixed to the lower die and has an inclined sliding surface that faces the punch The metal plate material is bent in a width direction while being slidably contacted with the inclined sliding surface of the cam driver and abutting on both sides in the width direction of the metal plate material. A die that presses both side portions against the side surface of the punch to form a predetermined shape, wherein the cam driver is a first cam driver in which the angle of the inclined sliding surface is raised. And the angle of the inclined sliding surface is A second cam driver that is more slender than the first cam driver, and the die is in contact with the metal plate material at a corner and presses the metal plate material against the side surface of the punch; and The upper surface is supported by the upper die so as to be slidable in the direction intersecting the press direction on the upper surface, and is brought into sliding contact with the first cam driver by descending so that the bending blade follows the bending locus of the metal plate material. The metal plate material is moved toward the side surface, and after the metal plate material comes into contact with the step portion of the punch, the metal blade material is further slid to come into contact with the second cam driver, and the bending blade is moved to the recessed corner portion of the step portion. Since the pressing position of the metal plate material by the bending blade can be concentrated at almost one point, the bending blade does not slip on the metal plate material, and therefore the bending blade is provided. By metal plate Bending unbending does not occur to the timber, it becomes possible to prevent the occurrence of the scan purine back.

It is the figure which showed the side surface cross section of the state after the press work of the press die concerning one embodiment of the present invention. It is A arrow directional view of FIG. It is side surface sectional drawing which shows the initial state of the press work of the press die concerning one embodiment of the present invention. It is side surface sectional drawing which shows the initial state which the convex part sliding surface of the suspension cam body contact | abutted the 1st cam driver of the press type | mold which concerns on one embodiment of this invention. It is side surface sectional drawing which shows the initial state which the recessed part sliding surface of the suspension cam body contact | abutted the 2nd cam driver of the press type | mold which concerns on one embodiment of this invention. It is side surface sectional drawing which shows the state in the middle of the movement of a press type | mold suspension cam body which concerns on one embodiment of this invention toward a punch with a 2nd cam driver. It is a schematic diagram which shows the pressing direction of the metal plate raw material by the press die concerning one embodiment of the present invention. It is another schematic diagram which shows the pressing direction of the metal plate raw material by the press die concerning one embodiment of the present invention. It is a schematic diagram which shows that a compressive force acts on a metal plate raw material by the press of the metal plate raw material with the press die concerning one embodiment of the present invention. It is a schematic diagram at the time of making the pressing direction of the metal plate raw material by the press die concerning one embodiment of the present invention multistage.

Explanation of symbols

10 Press Die 11 Lower Die 111 Punch 1113 Side 1115 Step 1117 Recess Corner 13 Upper Die 131 Pad 133 Cam Slider 20 Die 21 Bending Blade 211 Corner 25 Suspended Cam Body 251 Convex Sliding Surface 253 Concave Sliding Surface 30 Cam Driver 40 First cam driver 41 Inclined sliding surface 50 Second cam driver 51 Inclined sliding surface 70 Metal plate material 71 Folding assumed position θ1 When the die moves from the first bending position to the second bending position of the metal plate material The angle of entry θ2 with respect to the vertical line of the die The angle of entry with respect to the vertical line of the die when the die moves from the second bending position of the metal plate material to the concave corner

Claims (6)

The center part in the width direction of the flat metal plate material is sandwiched in the vertical direction by a pad and a punch having a step portion projecting outward from the recessed corner portion of the lower side surface, and both sides in the width direction of the metal plate material are sandwiched by dies. In a pressing method of pressing the metal plate material into a hat-shaped cross-section part consisting of a bottom part, a vertical wall part, and a flange part by pressing downward and pressing the side of the punch while bending.
A first step of lowering the corner portion of the die in contact with the assumed bending position of the vertical wall portion and the flange portion of the metal plate material and bending the metal plate material along the locus of the assumed bending position; ,
After the width direction both side part or side edge part of the said metal plate material contact | abuts to the said punch, the corner | angular part of the said die is advanced toward the concave corner part of the said punch, and a flange part is formed in the said metal plate material. Two steps,
A pressing method characterized by comprising: The pressing method according to claim 1,
In the first step, until the metal plate material contacts the stepped portion of the punch, the entry angle of the die toward the punch is θ1,
In the second step, the entry angle of the die toward the punch after the metal plate material contacts the step of the punch is θ2,
θ1 ≦ θ2
A pressing method of forming the die while changing the approach angle of the die toward the punch in two or more stages. The pressing method according to claim 2,
The approach angle of the die
θ1 = 0 ° -40 °, θ2 = 40 ° -90 °
A pressing method with two stages. A press die for realizing the pressing method according to claim 1. A punch that is fixed to the lower mold and has a top portion that supports the central portion in the width direction of the flat plate-shaped metal plate material from below, and a step portion that protrudes outward from a recessed corner portion of a lower side surface continuous from the top portion;
A pad that is supported by the upper mold and presses the center in the width direction of the metal plate material against the punch from above,
A cam driver fixed to the lower mold and having an inclined sliding surface facing the punch;
The metal plate material is bent while sliding down on the inclined sliding surface of the cam driver and contacting both sides in the width direction of the metal plate material. A die that presses the side of the punch and molds it into a predetermined shape,
The cam driver comprises a first cam driver having an upright angle of the inclined sliding surface, and a second cam driver having an inclined angle of the inclined sliding surface than the first cam driver,
The die is supported by the upper die so as to be slidable in a direction intersecting the press direction on the upper surface, a bending blade that contacts the metal plate material at a corner portion and presses the metal plate material against the side surface of the punch, The lower edge is brought into sliding contact with the first cam driver to move the bending blade toward the side of the punch along the bending locus of the metal plate material, and the metal plate material is moved to the step portion of the punch. A suspension cam body that is slidably contacted with the second cam driver by further lowering, and further moves the bending blade toward the recessed corner portion of the stepped portion,
A press die comprising. The press die according to claim 5,
The first cam driver and the second cam driver are arranged at overlapping positions in a side view of the moving direction of the die, and are alternately arranged in a comb blade shape in a direction parallel to the moving direction of the die. And a sliding surface provided on the lower surface of the suspension cam body is provided at a position corresponding to each inclined sliding surface of the first cam driver and the second cam driver. Press mold.

Images