JPWO2018168311A1 - Drawing machine - Google Patents

Abstract

In the drawing apparatus configured to cause the blank holder 32 and the pad 34 to perform different operations, the blank holder 32 has a shallow drawing depth from the first molding surface 31b having a deep drawing depth on the outer periphery of the mold 31. It is formed so as to go around the second molding surface 31c. The inner edge portion 32c of the contact surface 32a with the workpiece of the blank holder 32 is shaped along the curved surface 31d of the mold.

Description

  The present invention relates to a drawing apparatus for drawing a panel-shaped part.

  Generally, for example, an automobile door is configured by joining an inner panel 1 shown in FIGS. 1 to 3 and an outer panel (not shown). 1 shows the case where the inner panel 1 is viewed from the side of the vehicle, FIG. 2 is a perspective view of the inner panel 1, and FIG. 3 shows the case where the inner panel 1 is viewed from the direction of arrow A in FIG. ing. The inner panel 1 includes a panel body 10, a joint portion 11 that is provided on a peripheral portion of the panel body 10 and is joined to the outer panel by hemming, and a sash portion 12 that supports the window glass. As shown in FIG. 3, the panel body 10 has a shape in which a central portion in the vertical direction protrudes outward from the vehicle upper and lower ends, and an upper surface portion 10 a, a lower surface portion 10 b, and an end surface portion in the vehicle front-rear direction. 10c has a shape extending toward the outside of the vehicle interior. For this reason, usually, in the step of obtaining the inner panel 1 by press molding, the peripheral portion of the plate-like workpiece (material) is previously held by a holding member called a blank holder, and then drawn by a press molding die (also called draw molding). ) So that the center part overhangs.

  Moreover, since the dimension of the upper surface part 10a and the lower surface part 10b of the panel main body 10 in the vehicle interior / exterior direction is shorter than the dimension of the end surface part 10c in the vehicle interior / exterior direction, the upper surface part 10a and the lower surface part of the panel main body 10 The aperture at the portion where 10b is molded is shallow, and the aperture is deeper at the portion where the end surface portion 10c of the panel body 10 is molded. Thus, when a product with different drawing depths is pressed depending on the part, the conventional general drawing method in which the entire circumference is drawn with a uniform drawing depth tends to be wasteful of materials.

  That is, as shown in FIG. 3, the molding surface on the vehicle interior side of the inner panel 1 has a product shape that is curved outwardly of the vehicle interior, and therefore the die face D <b> 1 is usually set along the shape. In the drawing apparatus having such a die face D1, the entire circumference is drawn with a uniform drawing depth, so that there is extra material by the drawing height H in the vicinity of the sash portion 12 where the required drawing height is shallow. In other words, the outer dimensions (size) of the material used increase, resulting in a problem that the yield deteriorates and the manufacturing cost increases.

  In order to solve this problem, there is a method in which the die face D2 is set so that the aperture height H in the vicinity of the sash portion 12 is low. However, since the die face D2 is more curved than the die face D1, the curved surface The degree of deformation of the material as a whole in the direction of contraction increases when it is molded toward the inside. For this reason, it is difficult to design a mold so that the material is uniformly stretched, and wrinkles are likely to occur locally in the material.

  Therefore, for example, as disclosed in Patent Document 1, a blank holder for a shallow portion of a plate-like workpiece and a blank holder for a deep portion are provided, and a single workpiece is formed with different strokes. It is conceivable to perform drawing. In this case, a sill-shaped surplus portion is formed in the boundary portion of the punch so that cracks and wrinkles do not occur at the boundary portion where the drawing depth changes. Disperses and relieves unfavorable stress on the workpiece due to differences in operation.

JP 2017-1040 A

  As in Patent Document 1, by operating separately the blank holder for the shallow part of the plate-like workpiece and the blank holder for the deep part, the drawing depth of the single workpiece can be reduced. Although it is possible to mold shallow and deep parts, there is a concern that undesired stress may occur on the workpiece due to the difference in operation of the blank holder, so a sill-like surplus part is formed in the punch There is a need.

  However, because the sill-shaped surplus part is formed, the mold shape becomes complicated, and the manufacturing cost of the mold becomes high, and the surplus part is a trimmed part, resulting in waste of material, and the cause of deterioration in yield. There was a problem of becoming.

  The present invention has been made in view of such points, and an object of the present invention is to provide a drawing forming apparatus for drawing panel-like parts having different drawing depths, while avoiding complication of the mold shape. It is to suppress the occurrence of cracks and wrinkles and to further improve the yield.

  In order to achieve the above object, according to a first aspect of the present invention, a plate-shaped workpiece is formed by drawing so that a first side surface having a relatively large drawing depth and a second side surface having a small drawing depth are circumferentially disposed around the outer peripheral portion. A mold for forming a panel-like component formed continuously in a direction and having a boundary portion between the first side surface and the second side surface formed of a curved surface having a predetermined shape, It has a first mold and a second mold arranged so as to sandwich a plate-like workpiece in the thickness direction, and is driven in a direction in which one of the first mold and the second mold is in contact with or separated from the other. In the first mold, a first molding surface for molding the first side surface and a second molding surface for molding the second side surface are continuous in the circumferential direction of the first mold. And a boundary portion between the first molding surface and the second molding surface is a curved molding surface that molds the curved surface. A blank holder that holds the workpiece in the thickness direction together with the second mold is disposed at a portion corresponding to the first molding surface on the outer periphery of the first mold, and the second molding on the outer periphery of the first mold. In the portion corresponding to the surface, a pad for sandwiching the workpiece in the thickness direction together with the second mold is disposed, and in the drawing apparatus configured to cause the blank holder and the pad to perform different operations, The blank holder is formed so as to go around from the first molding surface side to the second molding surface side on the outer periphery of the first mold, and the inner edge portion of the blank holder on the contact surface to the workpiece is The curved surface is shaped along the curved surface.

  According to this configuration, the plate-like workpiece is pressed in the thickness direction by the first die and the second die, so that the first side surface having a deeper drawing depth and a shallow drawing depth are relatively formed on the outer peripheral portion. A panel-like component in which the second side surface is continuously formed in the circumferential direction and the boundary portion between the first side surface and the second side surface is configured by a curved surface having a predetermined shape can be molded.

  In this panel-shaped component molding step, a plate-shaped workpiece is sandwiched between the blank holder and the second mold disposed on the outer periphery of the first mold, and the pad disposed on the outer periphery of the first mold. A plate-shaped workpiece is sandwiched between the second mold. The blank holder is arranged to correspond to the first side surface having a relatively deep drawing depth, and the pad is arranged to correspond to the second side surface having a relatively small drawing depth. Since the blank holder and the pad perform different operations as in the conventional example, the first side surface with the deep drawing depth and the second side surface with the shallow drawing depth can be formed on a single plate-like workpiece.

  Since the contact surface of the blank holder is in contact with the workpiece and serves as a portion for clamping the workpiece, a force is applied so that the contact surface of the blank holder pulls the workpiece during drawing. The inner edge of the contact surface of the blank holder with the workpiece is shaped along the curved molding surface of the first mold, so that the workpiece can be placed along the curved molding surface of the first mold during drawing. Can be pulled. Thereby, cracks and wrinkles can be prevented from occurring at the boundary portion where the drawing depth changes without forming a sill-like surplus portion as in the conventional example in the mold. By eliminating the need for the sill-like surplus part, the complexity of the mold shape is avoided, and the surplus part of the work is reduced, resulting in less waste of material.

  According to a second aspect of the present invention, the blank holder and the pad are each formed with a bead that presses against the workpiece and suppresses a flow during drawing of the workpiece.

  According to this configuration, since the flow of the workpiece during drawing is suppressed, the forming accuracy of the panel-like component is improved.

  According to a third aspect of the present invention, an inner edge portion of a contact surface of the blank holder with the workpiece is substantially similar to the curved surface.

  According to the present invention, when panel-shaped parts having different drawing depths are drawn, the occurrence of cracking and wrinkling of the workpiece is suppressed while avoiding complication of the mold shape, and the yield is further improved. Can do.

It is a figure which shows the schematic shape of the inner panel seen from the vehicle side. It is a perspective view of an inner panel. It is a figure which shows the relationship between the schematic shape of the inner panel seen from the arrow A direction of FIG. 1, and die face. It is a top view of a lower mold. It is the perspective view which looked at the B section of Drawing 4 from the upper part. It is sectional drawing of the drawing apparatus corresponding to the VI-VI line in FIG. 4, and has shown the state which has an upper mold | type near top dead center. FIG. 7 is a view corresponding to FIG. 6 illustrating a state in which the upper die is lowered and the upper die and the blank holder start to sandwich the workpiece. FIG. 7 is a view corresponding to FIG. 6 showing a state in which the upper mold is near the bottom dead center. It is sectional drawing of the drawing apparatus corresponding to the IX-IX line in FIG. 4, and has shown the state which has an upper mold | type near top dead center. FIG. 10 is a view corresponding to FIG. 9 illustrating a state in which the upper die is lowered and the upper die and the blank holder start to sandwich the workpiece. FIG. 10 is a view corresponding to FIG. 9 showing a state in which the upper mold is near the bottom dead center. It is a simulation result image in the bottom dead center vicinity at the time of shape | molding an inner panel with the drawing apparatus which concerns on embodiment of this invention. 13 is a simulation result image at the same timing as in FIG. 12 in the case where the inner panel is formed by a drawing apparatus in which the front blank holder does not go around to the lower side according to the comparative example 1. FIG. 13 is a simulation result image at the same timing as FIG. 12 in the case where the inner panel is formed by a drawing apparatus having a shape in which the lower side pad extends linearly to the front blank holder side according to Comparative Example 2. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  1 to 3 show an inner panel 1 of an automobile door, and the inner panel 1 is a panel-like component formed by a drawing apparatus 20 (described later) according to an embodiment of the present invention. . The inner panel 1 can be made of various metals such as steel, and is obtained by drawing a metal plate material such as an aluminum alloy (a plate-like workpiece W in FIG. 6). It joins with the outer panel which is not illustrated, and becomes the door for motor vehicles (not shown). The workpiece W is also referred to as “material”.

(Configuration of inner panel 1)
The inner panel 1 includes a panel body 10, a joint portion 11 that is provided on a peripheral portion of the panel body 10 and is joined to the outer panel by hemming, and a sash portion 12 that supports the window glass. As shown in FIG. 3, the panel main body 10 has a shape such that the center portion in the vertical direction projects outward from the vehicle upper and lower end portions. An upper surface portion 10a extending outward from the passenger compartment is provided at the upper edge portion of the sash portion 12. A lower surface portion 10 b extending outward from the passenger compartment is provided at the lower edge of the panel body 10. Further, both end portions of the panel main body 10 in the vehicle front-rear direction are provided with end surface portions 10 c extending outward from the passenger compartment. The upper surface portion 10a, the end surface portion 10c, and the lower surface portion 10b are continuous in the circumferential direction of the inner panel 1. The upper surface portion 10a, the end surface portion 10c, and the lower surface portion 10b are portions obtained by drawing.

  As shown in FIG. 3, the dimension L1 from the edge in the vehicle front-rear direction at the center of the panel body 10 to the tip of the end face 10c is a dimension L2 from the lower edge of the panel body 10 to the tip of the bottom face 10b Is set longer than. Accordingly, the end surface portion 10c is a side surface (first side surface) having a relatively deep drawing depth, and the lower surface portion 10b is a side surface (second side surface) having a relatively small drawing depth. Further, as shown in FIG. 1, the boundary portion between the front end surface portion 10c and the lower surface portion 10b, that is, the corner portion is constituted by a curved surface 10e having a predetermined shape, and the rear end surface portion 10c and the lower surface portion 10b The boundary portion, that is, the corner portion is also constituted by a curved surface 10e having a predetermined shape. The shapes of the front curved surface 10e and the rear curved surface 10e may be different from each other. That is, on the outer peripheral portion of the inner panel 1, an end surface portion 10c having a relatively deep drawing depth and a lower surface portion 10b having a shallow drawing depth are continuously formed in the circumferential direction, and the end surface portion 10c and the lower surface portion are also formed. The boundary part with 10b is comprised by the curved surface 10e of predetermined shape.

(Overall configuration of the drawing apparatus 20)
As shown in FIGS. 6 and 9, the drawing apparatus 20 contacts and separates the lower mold 30 and the upper mold 40 for forming the inner panel 1 and one of the lower mold 30 and the upper mold 40 with respect to the other. And a mold driving device 50 for driving in the direction. The upper mold 40 is disposed above the lower mold 30. In this embodiment, the lower die 30 is fixed, and the upper die 40 is driven in the vertical direction by the die driving device 50 to come in contact with and separate from the lower die 30. The vicinity of the top dead center of the upper mold 40 is shown in FIGS. 6 and 9, respectively, and the vicinity of the bottom dead center of the upper mold 40 is shown in FIGS. 8 and 11, respectively. The mold driving device 50 can be composed of a power generation device such as a fluid pressure cylinder, and is controlled by a control device (not shown).

(Configuration of lower mold 30)
FIG. 4 is a plan view of the lower mold 30. In the description of this embodiment, for convenience of description, the lower mold 30 will be described with reference to each direction of the inner panel 1. That is, the “front side” of the lower mold 30 is the side on which the vehicle front side of the inner panel 1 is disposed, and the “rear side” of the lower mold 30 is the side on which the vehicle rear side of the inner panel 1 is disposed. . The “upper side” of the lower mold 30 is the side on which the vehicle upper side (roof side) of the inner panel 1 is disposed, and the “lower side” of the lower mold 30 is the vehicle lower side of the inner panel 1 ( (The floor side) is the side where it is placed.

  As shown in FIGS. 4, 6, and 9, the lower mold 30 includes a punch (first mold) 31, a front blank holder 32 provided on the front side of the punch 31, and a rear provided on the rear side of the punch 31. Side blank holder 33, lower die lower side pad 34 provided on the lower side of punch 31, lower die upper side pad 35 provided on the upper side of punch 31, front and rear cushion pins 36, 37 (FIG. 6). And a lower mold lower side gas spring 38 and a lower mold upper side gas spring 39 (shown in FIG. 9).

  The punch 31 is a member for transferring the product shape to the workpiece W from below, and is assembled to a lower mold holder (not shown) and fixed to a bolster (not shown) via the lower mold holder. ing. The upper surface of the punch 31 is a molding surface 31a. As shown in FIG. 9, an upper side guide member 30a is provided on the upper side of the punch 31 to guide the lower mold upper side pad 35 so as to be movable only in the vertical direction while restricting movement in the horizontal direction. Further, on the lower side of the punch 31, a lower side guide member 30b is provided for guiding the lower die lower side pad 34 so as to be movable only in the vertical direction while restricting movement in the horizontal direction.

  The upper surface of the punch 31 is formed so as to bulge upward so that the workpiece W can be drawn. That is, as shown in FIG. 5, the punch 31 has a first molding surface 31 b for molding the front end surface portion 10 c of the panel body 10 and a second molding for molding the lower surface portion 10 b of the panel body 10. The surface 31 c is provided so as to be continuous in the circumferential direction at the peripheral edge of the punch 31. Further, a boundary portion between the first molding surface 31 b and the second molding surface 31 c in the peripheral portion of the punch 31 is a curved surface 31 d for molding the curved surface 10 e of the panel body 10. Further, as shown in FIG. 4, the punch 31 also has a molding surface 31e for molding the rear end surface portion 10c of the panel body 10 and a molding surface 31f for molding the upper surface portion 10a of the panel body 10. It is provided at the peripheral edge of the punch 31.

  As shown in FIG. 5, the front blank holder 32 is a member that is disposed in a portion corresponding to the first molding surface 31 b on the outer periphery of the punch 31 and clamps the workpiece together with the upper mold 40 in the thickness direction. Further, the lower die lower side pad 34 is disposed at a portion corresponding to the second molding surface 31 c on the outer periphery of the punch 31, and is a member for holding the workpiece together with the upper die lower side pad 44 in the thickness direction.

  As shown in FIG. 4, the rear blank holder 33 is disposed at a portion corresponding to the molding surface 31 e of the punch 31, and is a member for holding the workpiece in the thickness direction together with the upper mold 40. The lower mold upper side pad 35 is disposed at a portion corresponding to the molding surface 31 f on the outer periphery of the punch 31, and is a member for holding the workpiece W in the thickness direction together with the upper mold upper side pad 45.

  FIG. 4 shows a lower mold including a blank holder, but the surrounding mold structure is omitted for easy understanding. In the plan view shown in FIG. 4, between the front blank holder 32 and the first molding surface 31b of the punch 31, between the lower mold lower side pad 34 and the second molding surface 31c of the punch 31, the rear blank holder 33 and Predetermined clearances are provided between the molding surface 31 e of the punch 31 and between the lower mold upper side pad 35 and the molding surface 31 f of the punch 31. Further, between the front blank holder 32 and the lower mold lower side pad 34, between the front blank holder 32 and the lower mold upper side pad 35, between the rear blank holder 33 and the lower mold lower side pad 34, the rear side A predetermined clearance is also provided between the blank holder 33 and the lower mold upper side pad 35. Mold internal structures such as front blank holder 32, rear blank holder 33, lower mold lower side pad 34, lower mold upper side pad 35 and guide so as to move relative to each other in the vertical direction while maintaining the clearance of these parts. (Not shown because of a well-known structure) is arranged and configured.

  In the present embodiment, the front blank holder 32 and the rear blank holder 33 are integrally formed at a peripheral portion not shown in FIG. 4 and are configured to perform the same operation.

  As shown in FIG. 5, the front blank holder 32 is formed so as to go around from the first molding surface 31 b side to the second molding surface 31 c side on the outer periphery of the punch 31. The upper surface of the front blank holder 32 is a contact surface 32a to the workpiece W. On the contact surface 32a of the front blank holder 32, a bead 32b is formed that presses against the workpiece W and suppresses the flow of the workpiece W during drawing. The bead 32b is formed of a concave bead and continuously extends from the upper side to the lower side of the front blank holder 32.

  An inner edge portion 32c is defined as an inner edge portion of the workpiece W on the contact surface 32a of the front blank holder 32. A portion of the inner edge portion 32c corresponding to the curved surface forming surface 31d has a shape along the curved surface forming surface 31d. Specifically, the inner edge portion 32c of the contact surface 32a is substantially similar to the curved surface 31d.

  The upper surface of the lower mold side pad 34 is a contact surface 34a to the workpiece W. On the contact surface 34a of the lower mold lower side pad 34, a bead 34b is formed which presses against the workpiece W and suppresses the flow of the workpiece W during drawing. The bead 34b is formed of a concave bead and continuously extends from the front side to the rear side of the lower mold lower side pad 34.

  As shown in FIG. 6, the upper surface of the rear blank holder 33 is a contact surface 33 a to the workpiece W. On the contact surface 33a of the rear blank holder 33, a bead 33b is formed which presses against the workpiece W and suppresses the flow during drawing of the workpiece W. The bead 33b is formed of a concave bead and continuously extends from the upper side to the lower side of the rear blank holder 33.

  As shown in FIG. 9, the upper surface of the lower mold upper side pad 35 is a contact surface 35 a to the workpiece W. A bead 35b is formed on the contact surface 35a of the lower mold upper side pad 35 so as to press the work W and suppress the flow of the work W during drawing. The bead 35b is formed of a concave bead, and continuously extends from the front side to the rear side of the lower mold upper side pad 35.

  As shown in FIG. 6, the front blank holder 32 is supported from below by a front cushion pin 36. The front cushion pin 36 is a member for holding the front blank holder 32 on which the workpiece W is placed at the raised end position shown in FIG. 6 and applying an urging force constantly upward, and has been conventionally known. When a downward force is applied to the front blank holder 32 from the upper die 40, the front cushion pin 36 moves downward as shown in FIG. 8, and the front blank holder 32 is in the lowered end position.

  The rear blank holder 33 is supported from below by a rear cushion pin 37 in the same manner as the front blank holder 32. The rear cushion pin 37 is configured in the same manner as the front cushion pin 36.

  As shown in FIG. 9, the lower die lower side pad 34 is supported from below by a lower die lower side gas spring 38. The lower mold lower side gas spring 38 is a member for holding the lower mold lower side pad 34 on which the work W is placed at the raised end position shown in FIG. It is. When a downward force is applied to the lower mold lower side pad 34 from the upper mold lower side pad 44, the lower mold lower side gas spring 38 is contracted as shown in FIG. 11, and the lower mold lower side pad 34 is moved to the lowered end position. Become.

  The lower mold upper side pad 35 is supported from below by the lower mold upper side gas spring 39 in the same manner as the lower mold lower side pad 34. The lower mold upper side gas spring 39 is configured in the same manner as the lower mold lower side gas spring 38.

  Thus, the lower mold lower side pad 34 and the lower mold upper side pad 35 are configured as separate members from the front blank holder 32 and the rear blank holder 33 that are integrally configured as described above, and are different from each other. Since it is supported by the support device, it can be operated separately. That is, the drawing apparatus 20 according to this embodiment performs different operations without interlocking the front blank holder 32 and the rear blank holder 33 with the lower mold lower side pad 34 and the lower mold upper side pad 35. It is configured. This is because the front blank holder 32 and the rear blank holder 33 are arranged so as to correspond to the deep drawing portion, while the lower die lower side pad 34 and the lower upper die pad 35 are shallow drawing portions. Because it is arranged to correspond to. Details of the operation will be described later.

(Configuration of upper mold 40)
As shown in FIG. 9, the upper mold 40 includes a die (second mold) 41, an upper mold lower side pad 44 provided on the lower side of the die 41, and an upper mold upper side provided on the upper side of the die 41. A pad 45, an upper mold lower side gas spring 48, and an upper mold upper side gas spring 49 are provided.

  The die 41 is a member for transferring the product shape to the workpiece W from above, and is disposed so as to face the punch 31 and is assembled to an upper mold holder (not shown). Fixed to a slide (not shown). Thereby, the die 41 and the punch 31 are disposed so as to sandwich the workpiece W in the thickness direction. The die 41 is driven in a direction in which the die 41 comes in contact with and separates from the punch 31. The lower surface of the die 41 is a molding surface 41a.

  As shown in FIG. 9, on the upper side of the die 41, there is provided an upper side guide member 41b for guiding the upper mold upper side pad 45 so as to be movable only in the vertical direction while restricting movement in the horizontal direction. A lower side guide member 41c for guiding the upper mold lower side pad 44 in the vertical direction is provided on the lower side of the die 41.

  As shown in FIG. 6, the upper mold work gripping portion 56 located on the front side of the molding surface 41 a of the die 41 is formed so as to face the contact surface 32 a of the front blank holder 32, and is a contact surface to the work W. It is said that. As a result, as shown in FIG. 7, the workpiece W can be clamped in the thickness direction by the upper workpiece gripping portion 56 of the die 41 and the contact surface 32 a of the front blank holder 32.

  A convex bead 41 d is formed on the upper work gripping portion 56 of the die 41 so as to press the work W and suppress the flow during drawing of the work W. The bead 41d of the die 41 and the bead 32b of the front blank holder 32 are arranged so as to face each other in the vertical direction. As shown in FIG. The bead 32b of the front blank holder 32 is pressed against the same portion of the workpiece W to deform the workpiece W. Thereby, the flow at the time of drawing forming the workpiece W is suppressed.

  Further, as shown in FIG. 6, the upper work gripping portion 57 located on the rear side of the molding surface 41 a of the die 41 is formed so as to face the contact surface 33 a of the rear blank holder 33. It is supposed to be the contact surface. As a result, as shown in FIG. 7, the workpiece W can be clamped in the thickness direction between the upper work gripping portion 57 of the die 41 and the contact surface 33 a of the rear blank holder 33.

  A convex bead 41 e that presses against the workpiece W and suppresses the flow during drawing of the workpiece W is formed in the upper workpiece gripping portion 57 of the die 41. The bead 41e of the die 41 and the bead 33b of the rear blank holder 33 are arranged so as to face each other in the vertical direction, and as shown in FIG. The bead 33b of the rear blank holder 33 is pressed against the same portion of the workpiece W to deform the workpiece W. Thereby, the flow at the time of drawing forming the workpiece W is suppressed.

  As shown in FIG. 9, the upper mold upper side pad 45 is arranged to face the lower mold upper side pad 35. The lower surface of the upper mold upper side pad 45 is a contact surface 45 a to the workpiece W. As shown in FIG. 10, the workpiece W can be sandwiched between the contact surface 45 a of the upper mold upper side pad 45 and the contact surface 35 a of the lower mold upper side pad 35 in the thickness direction.

  On the contact surface 45a of the upper mold upper side pad 45, a convex bead 45b that presses against the work W and suppresses the flow of the work W during drawing is formed. The beads 45b of the upper die upper side pad 45 and the beads 35b of the lower die upper side pad 35 are arranged so as to face each other in the vertical direction. As shown in FIG. The bead 45b of the mold upper side pad 45 and the bead 35b of the lower mold upper side pad 35 are pressed against the same part of the work W to deform the work W. Thereby, the flow at the time of drawing forming the workpiece W is suppressed.

  Further, as shown in FIG. 9, the upper die lower side pad 44 is disposed so as to face the lower die lower side pad 34. The lower surface of the upper mold lower side pad 44 is a contact surface 44 a to the workpiece W. As shown in FIG. 10, the workpiece W can be held in the thickness direction between the contact surface 44 a of the upper mold lower side pad 44 and the contact surface 34 a of the lower mold lower side pad 34.

  On the contact surface 44 a of the upper mold lower side pad 44, a convex bead 44 b is formed that presses against the workpiece W and suppresses the flow during drawing of the workpiece W. The beads 44b of the upper mold lower side pad 44 and the beads 34b of the lower mold lower side pad 34 are arranged so as to face each other in the vertical direction. As shown in FIG. The bead 44b of the lower mold side pad 44 and the bead 34b of the lower lower pad 34 are pressed against the same part of the work W to deform the work W. Thereby, the flow at the time of drawing forming the workpiece W is suppressed.

  Appropriate by adjusting specifications such as width, depth (in the case of concave beads), height (in the case of convex beads), clearance, etc. of the beads 32b, 33b, 34b, 35b, 41e, 41d, 44b, 45b The amount of inflow of the workpiece W can be reduced. In addition, the route by which the beads are arranged on the blank holder / pad is not limited to a linear route, and can be adjusted in consideration of the inflow amount. Usually, this adjustment work is performed by a method well known to those skilled in the art, such as a molding simulation or an on-site adjustment work.

  As shown in FIG. 9, the upper die lower side pad 44 is supported from above by an upper die lower side gas spring 48. The upper mold lower side gas spring 48 holds the upper mold lower side pad 44 in the lower position shown in FIG. 9, and when an upward force is applied to the upper mold lower side pad 44 from the lower mold 30 as shown in FIG. Thus, the upper mold lower side gas spring 48 is contracted to bring the upper mold lower side pad 44 into the upper position.

  The upper mold upper side pad 45 is supported from above by an upper mold upper side gas spring 49 in the same manner as the upper mold lower side pad 44. The upper mold upper side gas spring 49 is configured in the same manner as the upper mold lower side gas spring 48.

(Positional relationship of each member and setting of urging force of gas spring)
When the upper mold lower side gas spring 48 and the upper mold upper side gas spring 49 are not contracted (shown in FIGS. 6 and 9), the upper mold work gripping portion 56 of the die 41 (the contact surface 32a of the front blank holder 32) Facing portion), upper die work gripping portion 57 of die 41 (portion facing contact surface 33a of rear blank holder 33), contact surface 44a of upper die lower side pad 44 and contact surface of upper die upper side pad 45. The height of each member is set so that 45a becomes substantially the same height.

  A predetermined clamping force is applied to the workpiece W in the thickness direction by the lower mold lower side gas spring 38 and the upper mold lower side gas spring 48, and by the lower mold upper side gas spring 39 and the upper mold upper side gas spring 49. It can be generated.

  The urging force of the upper mold lower side gas spring 48 is stronger than the urging force of the lower mold lower side gas spring 38, and the urging force of the upper mold upper side gas spring 49 is applied to the lower mold upper side gas spring 39. It is set stronger than the power.

  Further, as will be described later, the blank holders 32 and 33 and the lower mold lower side pad 34 at the time of drawing are determined by the strength relationship of the gas springs, the stroke amounts thereof, the stroke amounts of the front and rear cushion pins 36 and 37, and the like. The movement timing and amount of movement of the lower mold upper side pad 35, the upper mold lower side pad 44, and the upper mold upper side pad 45 can be controlled. This may be set according to the shape of the product.

(Operation of the drawing apparatus 20)
Next, the operation of the drawing apparatus 20 configured as described above will be described. First, as shown in FIGS. 6 and 9, the upper die 40 is raised to a substantially top dead center position by the die driving device 50. Thereafter, the workpiece W blanked into a predetermined shape is conveyed by, for example, a robot, and the contact surface 32a of the front blank holder 32, the contact surface 33a of the rear blank holder 33, the contact surface 34a of the lower die lower side pad 34, and It is placed on the contact surface 35 a of the lower mold upper side pad 35. At this time, the upper mold work gripping portion 56, the upper mold work gripping portion 57, the contact surface 44a of the upper mold lower side pad 44, and the contact surface 45a of the upper mold upper side pad 45 are substantially the same height. .

  After the workpiece W is placed on the contact surfaces 32a, 33a, 34a, 35a, the upper die 40 is lowered by the die driving device 50, and the upper die workpiece gripping portion 56, the upper die workpiece gripping portion 57, the upper die lower side of the die 41 are lowered. The contact surface 44a of the side pad 44 and the contact surface 45a of the upper die upper side pad 45 are lowered while maintaining substantially the same height.

  When the upper mold 40 is lowered to the position shown in FIGS. 7 and 10, the upper mold work gripping part 56, the upper mold work gripping part 57, the contact surface 44 a of the upper mold lower side pad 44 and the upper mold upper side pad 45. The contact surface 45a is in contact with the upper surface of the workpiece W. As a result, the workpiece W is sandwiched between the upper mold 40 and the lower mold 30 in the thickness direction. When the upper die 40 is further lowered, the workpiece W is pressed against the molding surface 31a of the punch 31 and drawing is started on the entire circumference of the workpiece W.

  The lower die lower side pad 34 and the lower die upper side pad 35 are energized by the lower die lower side gas spring 38 and the lower die upper side gas spring 39, respectively, and the upper die lower side pad 44 and the upper die upper side pad 45. Are biased by an upper mold lower side gas spring 48 and an upper mold upper side gas spring 49, respectively. As described above, the urging forces of the upper mold lower side gas spring 48 and the upper mold upper side gas spring 49 are set to be stronger than the urging forces of the lower mold lower side gas spring 38 and the lower mold upper side gas spring 39. Therefore, in the first stage of drawing, the lower mold lower side gas spring 38 and the lower mold upper side gas spring 39 are contracted, and the upper mold lower side gas spring 48 and the upper mold upper side gas spring 49 are maintained without contracting. . That is, until the effective strokes of the lower mold lower side gas spring 38 and the lower mold upper side gas spring 39 are completed, the lower mold lower side gas spring 38 and the lower mold upper side gas spring 39 are contracted to lower the upper mold 40. Thus, the upper mold lower side gas spring 48 and the upper mold upper side gas spring 49 are not contracted. In this embodiment, the effective stroke amount of the lower mold lower side gas spring 38 is set to about 75 mm, and the effective stroke amount of the lower mold upper side gas spring 39 is set to about 35 mm. Further, an effective stroke amount of front and rear cushion pins 36 and 37 to be described later is set to about 135 mm. The stroke amount is an example.

  Thereby, in the first stage of drawing, the front blank holder 32, the rear blank holder 33, the lower mold lower side pad 34, the lower mold upper side pad 35, the upper mold lower side pad 44, and the upper mold upper side pad 45 are In a state where the workpiece W is sandwiched, the punch moves down together with the punch 31 as much as the effective strokes of the lower die lower side gas spring 38 and the lower die upper side gas spring 39, and the drawing process starts on the entire circumference of the workpiece W.

  When the effective strokes of the lower mold lower side gas spring 38 and the lower mold upper side gas spring 39 are completed, the process proceeds to the second stage of drawing, and the upper mold lower side gas spring 48 and the upper mold upper side gas spring 49 are contracted. start. The upper die lower side gas spring 48 and the upper die upper side gas spring 49 are contracted, so that the lowering operation of the upper die 40 is not hindered. The lower die lower side pad 34, the lower die upper side pad 35, the upper die lower side The side pad 44 and the upper mold upper side pad 45 continue to be stationary with the workpiece W sandwiched therebetween. As described above, drawing is performed on the side where the drawing depth is relatively shallow (the upper surface portion 10a and the lower surface portion 10b of the inner panel 1).

  On the other hand, drawing on the relatively deep drawing side (the front and rear end face portions 10c of the inner panel 1) is performed as follows. The die 41 is also lowered while the lower mold lower side pad 34, the lower mold upper side pad 35, the upper mold lower side pad 44, and the upper mold upper side pad 45 are moved to the stationary state and kept in the stationary state. The front blank holder 32 and the rear blank holder 33 are pushed downward by the lowering of the die 41 and the front and rear cushion pins 36 and 37 are contracted. Therefore, the front blank holder 32 and the rear blank holder 33 hold the workpiece W. It descends in the state. Drawing is continued until the front and rear cushion pins 36, 37 are stroked about 135 mm.

  In this manner, the lower mold lower side pad 34, the lower mold upper side pad 35, the upper mold lower side pad 44, and the upper mold upper side pad 45, and the front blank holder 32 and the rear blank holder 33 move differently. Due to this movement, the front and rear end face portions 10c where the inner panel 1 is deeply drawn is about 135 mm, the lower face portion 10b where the inner panel 1 is deeply drawn is about 75 mm, and the upper surface portion 10a is about 35 mm. Is done.

  Thereafter, the upper mold 40 performs the ascending operation. At this time, the ascending operations of the front blank holder 32 and the rear blank holder 33, the lower mold lower side pad 34, and the lower mold upper side pad 35 are performed in the same manner as when descending. When performed, the upper mold lower side pad 44 and the upper mold upper side pad 45 hold the work W from the bottom dead center to 60 mm and 100 mm, respectively, while the front blank holder 32 and the rear blank holder 33 work on the other parts. W may be pushed up, and the inner panel 1 as a product may be damaged. Therefore, when the upper die 40 is raised, a lock mechanism (not shown) is required for moving the upper die lower side pad 44 and the upper die upper side pad 45 in synchronization with the die 41. Since this lock mechanism has a conventionally well-known structure, description thereof is omitted.

  When the upper mold 40 rises to near the top dead center, the inner panel 1 is taken out by a robot or the like, for example. Thereafter, the next workpiece W is input, one cycle is completed, and the process proceeds to the next cycle. The above is the entire operation of one cycle of the drawing apparatus 20 according to this embodiment, and the inner panel 1 is continuously and automatically produced by repeating this cycle.

(Operation of front blank holder 32)
In the present embodiment, as shown in FIG. 5, the front blank holder 32 is formed so as to go around from the first molding surface 31b side to the second molding surface 31c side on the outer periphery of the punch 31, and in the contact surface 32a. The inner edge portion 32c is characterized by having a shape along the curved surface 31d of the punch 31. Hereinafter, the operation of this characteristic configuration will be described.

  First, as shown in FIGS. 6 and 9, when the upper mold 40 is near the top dead center, the front blank holder 32 and the lower mold lower side pad 34 have contact surfaces 32a and 34a having substantially the same height. Waiting to The workpiece W is placed on the contact surfaces 32a and 34a, and the upper die 40 starts to descend, and the upper die workpiece gripping portion 56 of the die 41 and the contact surface 44a of the upper die lower side pad 44 are on the upper surface of the workpiece W. When abutting, the peripheral portion of the workpiece W is sandwiched in the thickness direction by the urging forces of the gas springs 38 and 39 and the front and rear cushion pins 36 and 37. When the upper die 40 is further lowered, the front blank holder 32 and the lower die lower side pad 34 are both lowered while the predetermined tension acts on the workpiece W as described above, and the workpiece W is drawn. When the effective stroke 75 mm of the lower die lower side gas spring 38 is finished, the lower die lower side pad 34 stops descending, and the front blank holder 32 continues to be further drawn by about 60 mm in this state.

  At this time, since the inner edge portion 32c of the contact surface 32a of the front blank holder 32 extends along the curved surface 31d of the punch 31, the tension generated by the blank holder 32 is evenly applied to the curved surface 31d. After the action and lowering of the lower die lower side pad 34 has stopped, the drawing by the front blank holder 32 is performed while the material flows in appropriately and uniformly from the rank holder 32 side. Thereby, the crack of the material in the corner part of the inner panel 1 is suppressed.

  Further, without forming a sill-like surplus portion as in the conventional example in the mold, it is possible to prevent cracks and wrinkles from occurring at the boundary portion where the drawing depth changes. By eliminating the need for the sill-like surplus part, the mold shape is prevented from becoming complicated, and the surplus part of the workpiece W is reduced, resulting in less waste of material.

  Also, when designing the die so that the drawing depth is uniform by setting the die face according to the product shape, depending on the product shape, as explained in the background art section, the material may be reduced during drawing. Since deformation may occur in the shrinking direction, there is a limit to setting the die face according to the product shape in consideration of the occurrence of wrinkles during molding. However, in this embodiment, since the operation of the die face in the latter half of the drawing process can be changed depending on the molding site, the front blank holder 32, the rear blank holder 33, and the lower mold lower side pad 34 according to the drawing depth. And it can be set as the lower mold | type upper side pad 35, and a yield can be improved.

  In addition, since the inflow of material is small in the portion where the drawing depth is shallow, the material sandwiched between the lower die lower side pad 34 and the lower die upper side pad 35, the upper die lower side pad 44 and the upper die upper side pad 45 is used. Can be reduced. The front blank holder 32 and the lower mold lower side pad 34 are arranged with a predetermined clearance S (shown only in FIG. 5) in the horizontal direction in the vicinity of this portion, so that the front blank holder 32 and the lower mold lower side pad 34 are arranged. The undesired force applied to the material can be minimized by the different operation.

  Here, as shown in FIG. 5, a predetermined R shape is formed on one part of the lower die lower side pad 34 adjacent to the front blank holder 32. Thereby, after the lower mold | type lower side pad 34 stops, generation | occurrence | production of the crack in this one part when the front side blank holder 32 continues an action | operation can be prevented effectively.

(Effect of embodiment)
As described above, according to the drawing apparatus 20 according to this embodiment, the front blank holder 32 is moved from the first forming surface 31b having a deep drawing depth on the outer periphery of the punch 31 to the second forming surface having a shallow drawing depth. The inner edge portion 32 c of the contact surface 32 a of the front blank holder 32 with respect to the workpiece W is formed along the curved surface 31 d of the punch 31. Accordingly, since the workpiece W can be pulled along the curved surface 31d of the punch 31 during the drawing, it is possible to avoid complication of the mold shape when drawing the portions having different drawing depths. However, the occurrence of cracks and wrinkles on the workpiece W can be suppressed, and the yield can be further improved.

(Molding simulation result)
FIG. 12 is a simulation result image when the inner panel 1 is formed by the drawing apparatus 20 according to the embodiment of the present invention. The lower surface portion 10b and the front end surface of the panel body 10 near the bottom dead center of the drawing process. The boundary part 10e of the part 10c is shown. As is apparent from this image, almost no wrinkles are seen in the boundary portion 10e of the panel body 10 during drawing and the peripheral portion thereof.

  On the other hand, Comparative Example 1 shown in FIG. 13 is a simulation result image at the same timing as when the inner panel is formed by a drawing apparatus in which the front blank holder does not go around to the lower side. In the configuration of this comparative example 1, the sill-shaped surplus portion of the mold extends linearly in the direction of arrow D in FIG. 13, so that the front blank holder has the lower surface portion 10b of the panel body 10 being drawn and The material of the boundary portion of the front end portion 10c cannot be pulled appropriately, and wrinkles are generated in the boundary portion.

  Moreover, the comparative example 2 shown in FIG. 14 is a case where an inner panel is shape | molded with the drawing apparatus of the shape where the lower side pad extended linearly to the front side blank holder side. The lower side pad of this comparative example 2 extends linearly in the direction of arrow E in FIG. 14, and therefore when the front blank holder continues drawing after the lower side pad stops, the boundary portion 10e The material cannot be pulled moderately, and wrinkles are generated at the boundary portion.

(Other embodiments)
The above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  In the above embodiment, the case where the present invention is applied to the production of the inner panel 1 is described. However, the product is not limited to the inner panel 1, and various panel-like parts having different drawing depths. The present invention can be applied to the production of

  In addition, the present invention can be applied not only to a panel-like part having a shallow drawing depth only on two side surfaces, but also to a panel-like part having a shallow drawing depth on one side or three sides. is there.

  As described above, the drawing apparatus according to the present invention can be used when, for example, a panel-like part such as an inner panel of an automobile door is formed.

1 Inner panel (panel-like parts)
10b Lower surface (second side surface)
10c End face part (first side face)
10e Curved surface 20 Drawing device 30 Lower mold 31 Punch (first mold)
31b First molding surface 31c Second molding surface 31d Curved molding surface 32 Front blank holder 32a Contact surface 32b Bead 32c Inner edge 34 Lower mold lower side pad 34b Bead 40 Upper mold 41 Die (second mold)

Claims (3)

By drawing the plate-shaped workpiece, a first side surface having a relatively deep drawing depth and a second side surface having a shallow drawing depth are formed continuously in the circumferential direction on the outer peripheral portion, and the first side surface is formed. And a mold for forming a panel-like component in which a boundary portion between the second side surface and the second side surface is configured by a curved surface having a predetermined shape,
The mold has a first mold and a second mold arranged so as to sandwich the plate-like workpiece in the thickness direction, and one of the first mold and the second mold is in relation to the other. Driven in the direction of contact and separation,
The first mold has a first molding surface for molding the first side surface and a second molding surface for molding the second side surface continuous in the circumferential direction of the first mold. The curved portion forming the curved surface is a boundary portion between the first forming surface and the second forming surface,
In a portion corresponding to the first molding surface in the outer periphery of the first mold, a blank holder is disposed to hold the workpiece in the thickness direction together with the second mold,
In a portion corresponding to the second molding surface in the outer periphery of the first mold, a pad is provided for sandwiching the workpiece in the thickness direction together with the second mold,
In the drawing apparatus configured to cause the blank holder and the pad to perform different operations,
The blank holder is formed so as to go around from the first molding surface side to the second molding surface side in the outer periphery of the first mold,
The drawing apparatus according to claim 1, wherein an inner edge portion of a contact surface of the blank holder with the workpiece is shaped along the curved surface. In the drawing apparatus according to claim 1,
The blank holder and the pad are each formed with a bead that presses against the work and suppresses a flow during drawing of the work. In the drawing apparatus according to claim 1 or 2,
The drawing apparatus according to claim 1, wherein an inner edge portion of a contact surface of the blank holder with the workpiece is substantially similar to the curved surface.