JP5797066B2 - Press mold - Google Patents

Description

  The present invention relates to a press die for forming a press-formed product having a U-shaped cross section from a plate material.

  Conventionally, as a method of forming a side member having a U-shaped cross-section constituting a vehicle frame, a press working method for forming a press-molded product by pressing a material against a lower die with an upper die is widely used (for example, Patent Literatures 1 to 3).

  First, the side member will be described with reference to FIG.

  A large vehicle 4 such as a truck has a structure in which a cabin 4a and a loading platform 4b are supported by a frame 4c (FIG. 4 (a)), and the frame 4c includes a pair of side members 6 arranged in parallel with a plurality of cross members. The members 7 are connected to each other.

  The side member 6 is formed in a U-shaped cross section, and includes a web surface 61 standing along the side surface of the vehicle 4 and two flange surfaces 62 extending horizontally from both sides thereof. Further, the web surface 61 of the side member 6 has an offset portion 63a that is offset so as to expand outward in the horizontal plane on the cabin 4a side of the vehicle 4, and both the front and rear of the offset portion 63a are parallel to the side surface of the vehicle 4. Front web surface 63b and rear web surface 63c. Further on the front side of the vehicle 4 than the offset portion 63a, there is a shape changing portion 64 that changes the shape so that the interval between the flange surfaces 62, 62 is reduced on the cabin 4a side.

  In general, the side member 6 is formed by press-molding a steel plate having a shape in which the side member 6 is developed. The length of the side member 6 is about 4600 to 11000 mm according to the size of the vehicle 4 and the thickness is 6 ˜8 mm.

  A press die as shown in FIG. 5 is used for the press molding.

  The press mold 5 includes a punch 11 in an upper mold 10, a pad 22 facing the lower surface of the punch 11 on a lower mold 20, and a pair of dies positioned on both sides of the pad 22 and facing both side surfaces of the punch 11. Main bodies 21 and 21 are provided. The punch insert 11a is provided on the side surface of the punch 11 and the die insert 21a is provided on the inner side surface of the die body 21 by using the fixing bolts 11b and 21b, respectively. I can do it.

  By pressing the plate material placed on the die bodies 21 and 21 with the punch 11, both side portions of the plate material are bent and raised, and the web surface 11 is formed between the lower surface of the punch 11 and the pad 22. A flange surface 62 is formed between the side surface of the punch 11 and the inner side surface of the die body 21, and the cross-section of the plate material is formed in a U shape.

  Further, the punch 11 and the pad 22 have an offset forming portion in which the lower surface and the upper surface thereof are offset in the vertical direction in order to form the offset portion 63a of the side member 6 described in FIG. By further pushing the plate material with the punch 11 so as to hit the pad 22, an offset portion 63 a is formed, and the side member 6 is formed.

  In this press die 5, in order to prevent the punch 11 from being unable to be pulled out due to the biting of the flange surface 62, the clearance, which is the gap between the side surface of the punch 11 and the inner side surface of the die body 21, is set to the plate thickness +0. Generally, the width is about 5 mm.

Japanese Patent Laid-Open No. 4-118118 Japanese Patent Laid-Open No. 11-123469 JP 2010-149589 A

  However, when press molding is performed with the press die 5 having a clearance of about +0.5 mm, there is a problem that wrinkles are likely to occur on the flange surface 62 in the vicinity of the offset portion 63a.

  The generation of wrinkles will be described with reference to FIGS.

  In the vicinity of the offset portion 63a of the side member 6, more specifically, in the vicinity of the boundary between the offset portion 63a and the front web surface 63b, an offset contracted flange portion 65 in which the flange surface 62 is compressed and deformed by offset molding is formed. (A region surrounded by a dotted frame in FIG. 6A). During press molding, the offset shrinkage flange portion 65 is surrounded by surrounding materials. Therefore, if press molding is performed with the clearance of the press die 5 being larger than the plate thickness, the space between the plate material and the die is reduced. The material plays in the gaps formed in the gaps, and the bellows-like wrinkles 66 are easily formed.

  The shape of the wrinkle 66 has conventionally required strict accuracy. For example, the number of the wrinkles 66 should be one or less and the height thereof should be as small as possible (for example, within 0.3 mm per 100 mm length). . Since the side member 6 that does not satisfy the required accuracy requires a process of correcting the wrinkle 66, it is desirable to reduce the generation of the wrinkle 66.

  In order to reduce the generation of the wrinkles 66, it is necessary to eliminate the gap where the material plays in the vicinity of the offset forming portion and set the clearance to be smaller than the plate thickness of the plate, that is, to drive the clearance.

  However, if the clearance is pushed in, the biting of the flange surface 62 to the press die 5 becomes strong, so that the punch 11 may not lift from the bottom dead center, and the side member 6 is pressed by setting the clearance below the plate thickness. Molding technology has not been established.

  The present invention has been made to solve the above problems, and when forming a press-formed product having a U-shaped cross-section such as a side member from a plate member, the die body and An object of the present invention is to provide a press die that can drive a clearance between the punch and the punch.

  The present invention was devised to achieve the above object. The present invention comprises an upper die having a punch, a lower die having a pad opposed to the lower surface of the punch, and a pair of die bodies located on both sides of the pad and opposed to both side surfaces of the punch. And pressing the plate with the punch so as to hit the pad, forming a web surface of the press-formed product between the lower surface of the punch and the pad, and a flange surface between both side surfaces of the punch and the inner surface of the die body In a press die for forming a U-shaped press-molded product from a plate material, the clearance between the die body and the inner surface of the die body is kept below the plate thickness of the plate material while pressing on both side surfaces of the punch. This is a press die provided with a clearance driving / extraction means for narrowing the punch width and increasing the clearance when rising.

  The clearance driving / extracting means is provided so that the slide plate provided on the side surface of the punch and the outer side surface of the slide plate can be moved up and down, and the clearance between the inner side surface of the die body and the plate is less than the plate thickness when pushed. It is preferable to include a movable insert that descends along the slide plate when the punch is lifted from the bottom dead center to narrow the punch width and widen the clearance.

  The contact surface between the slide plate and the movable insert may be formed with an inclined slide surface that is inclined from the outer side to the inner side from the upper end to the lower end.

  The movable insert may be supported on the slide plate by a stripper bolt from an outer surface thereof, and an elongated hole that allows the stripper bolt to move in the vertical direction may be formed in the movable insert.

  The press-molded product includes a side member that forms a vehicle frame, the side member is formed in a U-shaped cross section, and has an offset portion that is spread outward on the cabin side in a horizontal plane, and is provided on the punch. The clearance driving / extracting means may be provided at a position corresponding to the offset portion.

  The punch may be formed with a concave groove that accommodates the clearance driving / extraction means at a position corresponding to the offset portion.

  It is preferable to further provide a die side clearance driving / extracting means on the inner side surface of the die main body so that the clearance with the side surface of the punch is kept below the plate thickness when pushed and the clearance is increased when the punch is raised.

  According to the present invention, when a press-formed product having a U-shaped cross section is formed from a plate material, a press die that can drive the clearance between the die body and the punch without imposing a burden on the punch or the die body. Can be provided.

It is a principal part enlarged view which shows the structure of the press metal mold | die which concerns on one embodiment of this invention, (a) is a front view, (b) is the AA arrow directional view of (a), (c) is It is a top view. It is sectional drawing of the press metal mold | die which concerns on one embodiment of this invention, (a) is before pushing a punch, (b) is the time of pushing in a punch, (c) is a figure which shows the time of punch extraction. It is a figure which shows the press die concerning other embodiment of this invention, (a) is a principal part enlarged plan view, (b) is sectional drawing of the press die at the time of punch pressing, (c) is punch extraction It is sectional drawing of the press die at the time. It is a schematic diagram which shows the structure of a vehicle, (a) is the whole track, (b) is a figure which shows a flame | frame. It is sectional drawing which shows the structure of the conventional press die. It is a figure which shows the wrinkles which generate | occur | produce in the offset shrinkage flange part of a side member, (a) is the whole perspective view of a side member, (b) is a perspective view of an offset shrinkage flange part, (c) is the front of an offset shrinkage flange part FIG.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  The structure of the press die according to this embodiment will be described with reference to FIGS. Here, as an example of the press mold, a press mold for forming the side member shown in FIG. 4 as a press-molded product will be described.

  1A and 1B are views showing the structure of a press die according to the present embodiment, where FIG. 1A is a front view, FIG. 1B is a view taken along the line AA in FIG. 1A, and FIG. It is. FIG. 2 is a cross-sectional view showing the structure of a press die according to the present invention, where (a) is before the punch is pushed in, (b) is when the punch is pushed in, and (c) is when the punch is removed. It is.

  As shown in FIGS. 1 and 2, the press die 1 includes a punch 11 in an upper die 10, and moves up and down in synchronization with the vertical movement of the punch 11 while facing the lower surface of the punch 11 in the lower die 20. And a pair of die bodies 21, 21 that are located on both sides of the pad 22 and face both side surfaces of the punch 11. The upper mold 10 and the lower mold 20 can form press molded products having various shapes and dimensions by exchanging the punch 11 and the pad 22 in accordance with the press molded product.

  The punch 11 provided in the upper mold 10 has a punch-side offset molding part 12a for forming the offset part 63a of the side member 6, and a front web surface 63b is formed in front and rear of the punch-side offset molding part 12a. A punch-side front molding part 12b for forming the rear web surface 63c and a punch-side rear molding part 12c for forming the rear web surface 63c. The punch 11 is composed of two punch bodies 11F and 11R divided front and rear at the punch side rear molding portion 12c so that the punch 11 can be easily replaced.

  On the other hand, the pad 22 provided in the lower mold 20 includes a pad side offset molding portion 23a for forming the offset portion 63a of the side member 6, a pad side front molding portion 23b for forming the front web surface 63b, and a rear web. A pad side rear molding portion 23c for forming the surface 63c is provided. Here, the pad 22 is composed of a single pad body. However, like the punch 11, the pad 22 may be divided into a plurality of pad bodies.

  The punch 11, the die body 21, and the pad 22 have a total length of about 4600 to 11000 mm in the longitudinal direction (left and right direction in FIG. 1) according to the size of the side member 6. FIG. 1 shows an enlarged view of a position corresponding to the vicinity of the offset portion 63a in which the wrinkles 66 are likely to occur, that is, the vicinity of the punch side and die side offset forming portions 12a and 23a. FIG.

  As shown in FIG. 2, by using this press die 1 and pressing the plate material 30 with the punch 11 so as to contact the pad 22, a web surface 61 is formed between the lower surface of the punch 11 and the pad 22, and the punch 11. The flange surface 62 is formed between both side surfaces of the die body 21 and the inner surface of the die body 21. Further, the offset member 63 a is formed by the respective offset forming parts 12 a and 23 a included in the punch 11 and the pad 22, whereby the side member 6 having a U-shaped cross section is formed from the plate material 30.

  In this press die 1, in order to reduce the occurrence of wrinkles 66 in the offset shrinkage flange portion 65, the clearance between the punch 11 and the die body 21 is made equal to or less than the plate thickness of the plate material 30 in the vicinity of the offset molding portions 12a and 23a. Press forming.

  Conventionally, in order to reduce the generation of wrinkles 66, if the press molding is performed with the clearance in the vicinity of the offset molding portions 12a and 23a, the punch 11 and the die body 21 are burdened by the biting of the flange surface 62. Since 11 may not lift from the bottom dead center, there is a problem that it cannot be adopted as a mass production method.

  Therefore, the press die 1 according to the present embodiment keeps the clearance with the inner side surface of the die body 21 below the plate thickness of the plate member 30 when the punch 11 is pushed into the both side surfaces of the punch 11 of the upper die 10 and when the punch 11 is raised. A clearance driving / extracting means 40 is provided which narrows the punch width and widens the clearance.

  Details of the clearance driving / extracting means 40 will be described.

  The clearance driving / extracting means 40 is provided on the side surface of the punch 11 so as to be movable up and down on the outer surface of the slide plate 41, and the clearance between the inner surface of the die body 21 and the plate member 30 when pushed. And a movable insert 42 that descends along the slide plate 41 to narrow the punch width and widen the clearance when the punch 11 is lifted from the bottom dead center.

  The slide plate 41 and the movable insert 42 are accommodated in a concave groove 43 formed by cutting out a part of the side surface of the punch 11. In the present embodiment, the concave groove 43 corresponds to a position corresponding to the offset portion 63a of the side member 6, more specifically, a position corresponding to the vicinity of the boundary between the offset portion 63a of the side member 6 and the front web surface 63b. Formed. The method for forming the concave groove 43 is not particularly limited. When the groove 43 is formed by cutting with a drill, a processing relief groove 44 as shown in FIG. it can. Moreover, the punch insert 11a used for the conventional press die 5 can be removed (see FIG. 5), and the slide plate 41 and the movable insert 42 can be accommodated at that position.

  The slide plate 41 has a wedge shape with a tapered lower end in a sectional view (see FIG. 2), and is formed so that the upper end is narrower than the upper bottom of the concave groove 43.

  The movable insert 42 has an inverted wedge shape with a tapered upper end in a cross-sectional view, and the clearance between the outer side surface and the inner side surface of the die body is equal to or less than the plate thickness of the plate member 30 when the groove 43 is settled on the upper bottom. Formed as follows.

  On the contact surface where the slide plate 41 and the movable insert 42 come into contact, an inclined slide surface 45 that is inclined from the outside to the inside from the upper end to the lower end is formed. As the movable insert 42 descends along the inclined slide surface 45, the distance between both side surfaces of the punch 11, that is, the punch width is reduced, and the clearance is increased.

  In this embodiment, the clearance increase amount is adjusted by the inclination angle of the inclined slide surface 45 (the inner angle formed by the inclined slide surface 45 and the upper bottom of the groove 43). For example, in the case where the side member 6 having a larger offset amount is molded, the inclination angle is decreased to greatly increase the clearance. Since the wrinkle 66 is more likely to occur in the side member 6 having a large offset amount, the clearance in the vicinity of the offset forming portions 12a and 23a can be further driven by reducing the inclination angle, thereby reducing the generation of wrinkles. can do.

  The slide plate 41 is provided on the side surface of the punch 11. More specifically, the slide plate 41 is fixed to the side portion of the concave groove 43 by a fixing bolt 41a. The movable insert 42 is provided on the outer surface of the slide plate 41. More specifically, the movable insert 42 is supported on the slide plate 41 by the stripper bolt 42 a from the outer surface of the movable insert 42 in a state where it is in contact with the outer surface of the slide plate 41.

  In the present embodiment, the slide plate 41 is fixed and the movable insert 42 is supported by four fixing bolts 41a and four stripper bolts 42a arranged in a square shape when viewed from the front (see FIG. 1A). ing. However, in the present invention, the number and arrangement of these bolts 41a and 42a are not particularly limited.

  The movable insert 42 is formed with a long hole 42b that allows the stripper bolt 42a to move in the vertical direction. The stripper bolt 42a is inserted into the long hole 42b and the movable insert 42 is supported by the slide plate 41, so that the vertical movement of the movable insert 42 is allowed in the long hole 42b. The dimension of the long hole 42b is not particularly limited, but the long diameter is set to, for example, the body diameter of the stripper bolt 42a + about 10 mm so that the moving amount of the stripper bolt 42a and the movable insert 42 does not become too small. In this case, the stripper bolt 42a and the movable insert 42 are allowed to move about 10 mm in the vertical direction.

  A spring 46 for biasing the movable insert 42 downward and assisting the lowering of the movable insert 42 is set on the upper bottom of the concave groove 43. The spring 46 is made of an elastic material such as urethane and is accommodated in a spring hole 46 a formed in the upper bottom of the concave groove 43 above the movable insert 42. Further, the spring 46 is formed at such a height as to be separated from the upper end of the movable insert 42 before the punch is pushed in or after the punch is removed, and the urging force acts on the movable insert 42 only when the punch 11 starts to rise. During this period, the urging force is prevented from working. When the biting force of the side member 6 is further increased, the height of the spring 46 is increased to prevent the movable insert 42 from adhering and the clearance from expanding. A large urging force may be exerted.

  Next, the operation of the present embodiment will be described with reference to FIG.

  First, as shown in FIG. 2A, a plate material 30 (steel plate) for forming the side member 6 is placed on the upper surfaces of the pair of die bodies 21 and 21. At this time, the movable insert 42 is lowered by its own weight along the inclined slide surface 45, and the clearance is wider than the plate thickness of the plate member 30.

  When the lowered punch 11 hits the plate material 30, the movable insert 42 is first lifted along the inclined slide surface 45 by the plate material 30, the punch width is expanded, and the clearance becomes smaller than the plate thickness of the plate material 30.

  Thereafter, as shown in FIG. 2B, the plate 30 is pushed between the pair of die bodies 21 and 21 while being sandwiched between the pads 22 by the punch 11, whereby both side portions 30s and 30s of the plate 30 are bent and raised. To do. Thereafter, the plate material 30 is further pushed in, whereby a web surface 61 is formed between the lower surface of the punch 11 and the upper surface of the pad 22, and a flange surface 62 is formed between the side surface of the punch 11 and the inner surface of the die body 21. At the same time, an offset part 63a is formed by the offset molding parts 12a and 23a (see FIG. 1), and the side member 6 is molded.

  During this time, the position of the movable insert 42 is maintained at the upper bottom of the concave groove 43 by the reaction force from the plate material 30, so that the clearance is kept constant below the plate thickness of the plate material 30. Accordingly, the occurrence of wrinkles 66 is reduced in the offset contraction flange portion 65 of the side member 6.

  After the punch 11 is pushed in, the side member 6 bites into the punch 11 and the die body 21, but when the punch 11 is raised as shown in FIG. 2C, the movable insert 42 moves along the inclined slide surface 45. Lowering, punch width narrows and clearance increases. As a result, the punch 11 can be smoothly extracted from the lower mold 20, and the burden on the punch 11 and the die body 21 can be reduced when the punch 11 is extracted.

  When the punch 11 is extracted from the lower mold 20, the side member 6 does not bite against the movable insert 42. Therefore, the movable insert 42 naturally returns to its original position, and mass production of the side member 6 efficiently with stable quality. Can be performed.

  In short, in the press die 1 according to the present embodiment, the clearance between the side surface of the punch 11 and the side surface of the punch 11 is kept constant below the plate thickness of the plate 30 at the time of pressing on both side surfaces of the punch 21 provided in the upper die. A clearance driving / extracting means 40 is provided to narrow the punch width and widen the clearance when rising (when extracting).

  Thereby, when the side member 6 having a U-shaped cross section is formed from the plate member 30, the generation of wrinkles 66 at the offset shrinkage flange portion 65 of the side member 6 can be reduced.

  Further, by reducing the generation of wrinkles 66, correction of the wrinkles 66 after press molding can be made unnecessary.

  Furthermore, since the burden on the die body 21 and the punch 11 can be reduced, the side member 6 can be mass-produced even if the clearance is driven below the plate thickness of the plate 30.

  The present invention is not limited to the above-described embodiment, and various modifications can be made.

  For example, as shown in FIG. 3, the clearance between the side surface of the punch 11 and the side surface of the punch 11 is kept to be equal to or less than the plate thickness of the plate member 30 when being pushed into the inner surface of the die body 21 provided in the lower mold 20 and the clearance is expanded when the punch 11 is raised. A press die 3 further provided with die side clearance driving / extracting means 50 may be used.

  The die side clearance driving / extracting means 50 has the same configuration as the clearance driving / extracting means 40 provided on the punch 11, and a die side slide plate 51 provided on the inner surface of the die body 21, and a die side slide. It consists of a die-side movable insert 52 provided on the inner surface of the plate 51.

  The die side slide plate 51 and the die side movable insert 52 are accommodated in a die side groove 53 formed by cutting out a part of the inner surface of the die body 21, and the die side groove 53 is formed in the punch 11. Similar to the concave groove 43, it is formed at a position corresponding to the offset portion 63 a of the side member 6.

  A contact surface between the die side slide plate 51 and the die side movable insert 52 is formed with a die side inclined slide surface 54 that is inclined from the inner side to the outer side from the lower end to the upper end, and the die side movable along the die side inclined slide surface 54. As the insert 52 rises, the clearance with the side surface of the punch 11 increases.

  The die side slide plate 51 is fixed to the inner side surface of the die side groove 53 by a fixing bolt 51a. The die-side movable insert 52 is supported on the die body 21 by the stripper bolt 52a through the die-side slide plate 51, and an elongated hole 52b that allows the stripper bolt 52a to move in the vertical direction is formed in the die body 21 and the die-side slide plate 51. Is done.

  In the press die 3, the die side clearance driving / extracting means 50 is further provided, so that the clearance can be greatly expanded when the punch 11 is extracted, and the burden on the punch 11 and the die body 21 is further reduced. It becomes possible.

  Moreover, although the said embodiment demonstrated the press metal mold | die which press-molds the side member 6, this invention is applicable to all the press metal mold | dies which shape | mold the press-molded product of a cross-sectional U shape.

  Furthermore, the clearance driving / extracting means 40 (and the die side clearance driving / extracting means 50) can be further provided at a position corresponding to the shape changing portion 64, and wrinkles can be reduced in the shape changing portion 64.

1 Press mold 6 Press-molded product (side member)
DESCRIPTION OF SYMBOLS 10 Upper mold | type 11 Punch 20 Lower mold | type 21 Die body 21a Die insert 21b Fixing bolt 22 Pad 30 Plate material 30s Side part 40 Clearance drive-in / out means 41 Slide plate 42 Movable insert 42a Stripper bolt 42b Elongated hole 43 Concave groove 45 Inclined slide surface 61 Web surface 62 Flange surface

Claims (5)

The upper die is equipped with a punch, the lower die is provided with a pad facing the lower surface of the punch and a pair of die bodies located on both sides of the pad and facing both sides of the punch, and the plate is pushed by the punch so as to hit the pad. The web surface of the press-molded product is formed between the lower surface of the punch and the pad, and the flange surface is formed between the both side surfaces of the punch and the inner surface of the die body. In the press mold for molding
On both sides of the punch, a clearance thrust-sampling means for expanding the clearance by narrowing the punch width ascent of the punch together with keeping the clearance between the inner surface of the die body below the plate thickness of the plate at the time of pushing provided, the clearance thrust- The extraction means is provided on the slide plate provided on the side surface of the punch and on the outer side surface of the slide plate so as to be vertically movable, and when pushed, the clearance between the inner side surface of the die body is kept below the plate thickness of the plate material, It consists of a movable insert that descends along the slide plate when it is lifted from the bottom dead center and narrows the punch width to widen the clearance. The movable insert has a vertical direction of the above stripper bolt. Press mold, characterized in that the elongated hole allows movement is formed. The press die according to claim 1, wherein an inclined slide surface that is inclined from the outside to the inside from the upper end to the lower end is formed on a contact surface between the slide plate and the movable insert. The press-molded product is composed of a side member that forms a vehicle frame, and the side member is formed in a U-shaped cross section and has an offset portion that is expanded outward in the horizontal plane on the cabin side,
The press die according to claim 1 or 2, wherein the clearance driving / extracting means provided in the punch is provided at a position corresponding to the offset portion. 4. The press die according to claim 3 , wherein the punch is formed with a concave groove for accommodating a clearance driving / extracting means at a position corresponding to the offset portion. The inner surface of the die body, further to any claims 1 to 4 in which a die-side clearance thrust-sampling means for expanding the clearance ascent of the punch together with keeping the clearance between the side surface of the punch below the plate thickness of the plate at the time of pushing The described press die.