JP5649050B2 - Press molding method and press molding apparatus - Google Patents

Description

  The present invention relates to a press molding method and a press molding apparatus.

  Panel members and frame members constituting the body of an automobile are formed by press working. For example, it is conceivable to form a hat-shaped part or a U-shaped part by simple bending of a metal plate. However, in this case, since the ridge line of the bent portion of the component needs to be a straight line, the shape of the component is remarkably limited. For example, as shown in FIG. 11 and FIG. A part with a curved edge cannot be formed.

  For this reason, parts such as FIG. 11 and FIG. 12 are subjected to a drawing process to form the top surface into a desired shape, and then the flange part provided in the molded product is subjected to a drawing process (bending process, etc.). Is often formed. As described above, according to the drawing process, parts having various shapes can be molded, so that versatility is improved and the yield is increased by stretching the material. However, since the process of processing the flange portion after drawing is required, the cycle time becomes long, and the processing cost is increased because processing equipment is required for each process.

  For example, Patent Document 1 discloses a press molding apparatus that can perform drawing and bending with one apparatus. In this press working apparatus, after drawing with a cutting tool, the cutting tool is once raised, the cam member is operated to switch the position of the cutting tool, and the cutting tool is lowered again to perform bending.

JP-A-8-174084

  According to the press working apparatus of Patent Document 1, work efficiency and equipment costs can be improved as compared with the case where each process is performed by a separate apparatus. However, since it is necessary to reciprocate the cutting tool a plurality of times and an actuator for switching the position of the cutting tool is required, it cannot be said that improvement in work efficiency and reduction in equipment cost are sufficient.

  The problem to be solved by the present invention is to reduce the cycle time and the equipment cost by performing the drawing process and the processing of the flange portion in one process.

The present invention made in order to solve the above-mentioned problems is a press molding method by a press molding apparatus comprising a punch having a molding surface, a die provided so as to be movable up and down with respect to the punch, and a blank holder. And while holding both ends of the metal plate with the blank holder, the die, the blank holder, and the metal plate are lowered with respect to the punch, and the metal plate is pressed against the punch forming surface along the punch forming surface. Forming a molded part, a flange part sandwiched between a die and a blank holder, and an intermediate formed product having a vertical wall part provided between the molded part and the flange part by drawing, a die, and the blank holder, together with further lowered beyond the drawing is completed a predetermined position, lower the blank holder in a direction inclined to the drop direction of the die Allowed, and by moving the blank holder from the flange portion in the inflow direction of the material to the vertical wall portion of the intermediate product, the flow of material from the flange portion of the intermediate molded article to the vertical wall portion from said predetermined position before It is accelerated and a step of forming a final molded article, the guide member having a sloping guide surface to the blank holder guiding in a direction the inclined, provided below the blank holder, the blank holder, A return guide surface having a slide surface that is inclined so as to be guided by the guide surface of the guide member and a return slide surface that is parallel to the slide surface, and the punch is inclined so as to guide the return slide surface of the blank holder The blank holder is lowered in the inclined direction and moves in the direction of material flow from the flange portion to the vertical wall portion in the intermediate molded product. Occasionally, the slide surface and return the slide surface of the blank holder is intended to fit between the guide surface and the punch of the return guide surface of the guide member.

  In this way, after the die and the blank holder are lowered with respect to the punch and subjected to drawing processing, the die and the blank holder are further lowered to flow the material of the flange portion into the vertical wall portion, whereby the die and the blank holder It is possible to perform drawing processing and processing of the flange portion with a single descent. Therefore, compared with the case where these processes are performed by a separate apparatus, the cycle time can be shortened and the equipment cost can be reduced.

  By the way, in the drawing process, it is preferable to stretch the material until just before it breaks (molding limit point) in order to increase the yield and to accurately follow the shape of the molding surface of the punch. In this case, if the blank holder is lowered beyond the forming limit point while restraining the end of the metal plate, the metal plate may be broken. Therefore, in the press forming method of the present invention, as described above, when the blank holder is lowered beyond a predetermined position (for example, the forming limit point) and the flange portion is processed, the flange portion is removed from the flange portion rather than at the time of drawing. Measures are taken to promote the inflow of material into the vertical wall. Thereby, the material of a flange part can be actively flowed into a vertical wall part, and the process of a flange part can be performed, preventing the situation where a metal plate fractures | ruptures.

The above press molding method can be performed, for example, by moving the blank holder in the inflow direction of the flange portion while lowering the blank holder. Such a method, a punch having a forming surface, and a die and a blank holder which is movable up and down relative to the punch, while holding the both ends of the metal plate in the die and the blank holder, die, the blank A holder, and a metal plate that is lowered with respect to the punch and presses the metal plate against the molding surface of the punch, thereby forming a molding portion formed along the molding surface of the punch, a flange portion sandwiched between the die and the blank holder, and Then, an intermediate molded product having a vertical wall portion provided between the molding portion and the flange portion is molded by drawing, and the blank holder is lowered in the same direction as the die up to a predetermined position. with lowering the direction inclined with respect to the drop direction from the flange portion in the intermediate article by moving in the inflow direction of the material to the vertical wall portion, the intermediate product It is a press molding device that forms the final molded product by promoting the inflow of material from the lunge portion to the vertical wall portion than before the predetermined position, and is inclined so as to guide the blank holder in the inclined direction. A guide member having a guide surface is provided below the blank holder, and the blank holder has a slide surface inclined so as to be guided by the guide surface of the guide member and a return slide surface parallel to the slide surface. The punch has a return guide surface that is inclined so as to guide the return slide surface of the blank holder, and the blank holder is lowered in the inclined direction to move from the flange portion to the vertical wall portion in the intermediate molded product. When moving in the material inflow direction, the slide surface of the blank holder and the return slide surface are between the guide surface of the guide member and the return guide surface of the punch. It can be realized by the press forming apparatus to be fitted.

  Or said press molding method can be performed by making the holder pressure at the time of processing a flange part smaller than the holder pressure at the time of drawing.

  As described above, according to the present invention, the drawing process and the processing of the flange portion can be performed with a single descent of the die and the blank holder, so that the cycle time and the equipment cost can be reduced.

It is sectional drawing of the press molding apparatus which performs the press molding method which concerns on 1st Embodiment of this invention. It is a top view in the XX line of the press molding apparatus of FIG. It is sectional drawing of the blank holder of the said press molding apparatus. It is sectional drawing which shows a mode that press molding is performed with the said press molding apparatus (molding limit point). It is sectional drawing which shows a mode that press molding is performed with the said press molding apparatus (blank holder width direction movement). It is sectional drawing which shows a mode that press molding is performed with the said press molding apparatus (at the time of shaping | molding completion). It is sectional drawing of the press molding apparatus which performs the press molding method which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows a mode that press molding is performed with the press molding apparatus which concerns on 2nd Embodiment (molding limit point). It is sectional drawing which shows a mode that press molding is performed with the press molding apparatus which concerns on 2nd Embodiment (holder pressure 0). It is sectional drawing which shows a mode that press molding is performed with the said press molding apparatus (at the time of shaping | molding completion). It is a perspective view of a U-shaped component of a cross section. It is a perspective view of components of a section hat shape. It is sectional drawing of the blank holder which provided the step bead. It is sectional drawing of the blank holder which provided the step bead (at the time of blank holder width direction movement).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The press molding apparatus 1 according to the first embodiment of the present invention includes a punch 10 having a molding surface 11 on an upper surface, a die 20 that can be raised and lowered with respect to the punch 10, and a vertically movable with respect to the punch 10. And a blank holder 50 that holds the end portion of the metal plate from above and below in cooperation with the die 20. The “vertical direction” refers to the direction in which the die 20 moves up and down with respect to the punch 10, and the side away from the punch 10 is referred to as the upper side, and the side approaching the punch 10 is referred to as the lower side. Moreover, the left-right direction of FIG. 1 among the directions orthogonal to an up-down direction is called a "width direction." In addition, the press molding apparatus 1 is not necessarily limited to the configuration used in the direction shown in FIG. 1, and may have a configuration that is upside down with respect to FIG. 1, for example.

  The punch 10 has a molding surface 11 formed on the upper surface, side surfaces 12 extending downward from both ends of the molding surface 11 in the width direction, and extending in a direction inclined downward from the lower end of the side surface 12 toward the center in the width direction. A return guide surface 13 is formed. This return guide surface 13 plays a role of guiding the outer side in the width direction when the blank holder 50 is raised (details will be described later).

  The die 20 cooperates with the molding surface 11 of the punch 10 to form a molding surface 21 that sandwiches the metal plate from above and below, and cooperates with the blank holder 50 to hold the both ends of the metal plate W in the width direction. The side surface 23 is provided between the molding surface 21 and the pressing surface 22 and extends upward from the inner end of the pressing surface 22 in the width direction. The die 20 is moved up and down by a drive unit (cylinder or the like) not shown.

  The blank holder 50 has a pressing surface 51 that holds both ends in the width direction of the metal plate W in cooperation with the pressing surface 22 of the die 20, and is supported from below by a support portion (for example, a cylinder 52) so as to be lifted and lowered. Yes. The blank holder 50 can adjust the holder pressure (the force for clamping the metal plate W). In this embodiment, the holder pressure of the blank holder 50 can be adjusted by adjusting the pressure of the cylinder 52. The side surface 53 on the inner side in the width direction of the blank holder 50 is a sliding surface that slides on the side surface 12 of the punch 10 and is formed in a planar shape extending in the vertical direction in the illustrated example. On the lower surface of the blank holder 50, a slide surface 54 that is inclined inward in the width direction is formed. As shown in FIG. 3, a concave portion 56 is provided on the lower surface of the blank holder 50, and the blank holder 50 can be moved in the width direction with respect to the cylinder 52 by the size of the concave portion 56 (see FIG. 3). (See dotted line 3). A return slide surface 55 that is inclined inward in the width direction toward the lower side is formed at the inner end in the width direction of the upper surface of the blank holder 50. In the illustrated example, the slide surface 54 and the return slide surface 55 of the blank holder 50 are provided in parallel.

  The blank holder 50 descends in the same direction as the lowering direction of the die 20 (vertical direction in FIG. 1) until a predetermined position, and descends in a direction inclined with respect to the lowering direction of the die when the predetermined position is exceeded. Yes. In the present embodiment, a guide member 60 is provided below the blank holder 50, and the blank holder 50 is guided by the guide member 60, whereby the blank holder 50 is lowered in a direction inclined inward in the width direction. On the upper surface of the guide member 60, a guide surface 61 that is inclined inward in the width direction toward the lower side is formed. The guide surface 61 is formed in parallel with the slide surface 54 of the blank holder 50. The direction in which the descending direction of the blank holder 50 is inclined is not limited to the inner side in the width direction, and may be inclined to the outer side in the width direction, for example.

  Next, a method for press forming the metal plate W using the above press forming apparatus 1 will be described.

  First, as shown in FIG. 1, the metal plate W is placed on the pressing surfaces 51 of the pair of blank holders 50 provided on both sides in the width direction of the punch 10, and the die 20 is lowered in this state. As a result, the pressing surface 22 of the die 20 and the pressing surface 51 of the blank holder 50 sandwich the both ends in the width direction of the metal plate W from above and below.

  When the die 20 is further pressed downward and the applied pressure exceeds the pressure of the cylinder 52 of the blank holder 50, the die 20, the blank holder 50, and the metal plate W are lowered integrally, and the metal plate W is drawn. Is done. At this time, the holder pressure of the blank holder 50 is equal to the pressure of the cylinder 52. The blank holder 50 is lowered while sliding the side surface 53 on the inner side in the width direction with the side surface 12 of the punch 10. By drawing the metal plate W in this way, as shown in FIG. 4, the forming portion W <b> 1 formed by the forming surface 11 of the punch 10, the pressing surface 22 of the die 20, and the pressing surface 51 of the blank holder 50 are used. An intermediate molded product W ′ composed of the sandwiched flange portion W3 and the vertical wall portion W2 stretched in the vertical direction between the molded portion W1 and the flange portion W3 is formed, and the drawing process is completed.

  Thereafter, by further lowering the die 20 and the blank holder 50 from the position shown in FIG. 4, the processing of the flange portion W3 is performed. However, in the state shown in FIG. 4, the intermediate molded product W ′, in particular, the vertical wall portion W2 is at the molding limit point, and if the die 20 and the blank holder 50 are lowered as they are and the vertical wall portion W2 is further stretched, the vertical wall The part W2 may be broken. In the press molding method according to the present invention, when the die 20 and the blank holder 50 are lowered beyond a predetermined position (the molding limit point in the present embodiment), the flange W3 of the intermediate molded product W ′ is moved to the vertical wall W2. Measures will be taken to facilitate the inflow of materials. In the present embodiment, the material inflow promoting means is configured by moving the blank holder 50 in the material inflow direction (inward in the width direction) while lowering the blank holder 50. Specifically, when the die 20 and the blank holder 50 are further lowered from the state shown in FIG. 4, the slide surface 54 of the blank holder 50 is guided by the guide surface 61 of the guide member 60 as shown in FIG. The blank holder 50 descends in a direction inclined inward in the width direction. At this time, the blank holder 50 is lowered while the slide surface 54 and the return slide surface 55 of the blank holder 50 are fitted between the guide surface 61 of the guide member 60 and the return guide surface 13 of the punch 10. Move in the width direction in a stable state. Thus, when the blank holder 50 moves inward in the width direction, the movement inward in the width direction of the flange portion W3 pressed by the pressing surface 51 of the blank holder 50 is promoted. Thereby, the material of the flange part W3 can be made to flow into the vertical wall part W2, preventing the fracture | rupture in the bending part between the vertical wall part W2 and the vertical wall part W2 and the flange part W3. At this time, the material of the flange portion W <b> 3 flows into the vertical wall portion W <b> 2 while being rubbed at the corner portion between the pressing surface 22 and the side surface 23 of the die 20. Further, by guiding the blank holder 50 with the inclined surfaces (the slide surface 54 and the guide surface 61) provided on the blank holder 50 and the guide member 60, the blank holder 50 can be moved inward in the width direction without requiring a separate drive mechanism. Can be moved.

  As shown in FIG. 6, when the die 20 and the blank holder 50 reach the bottom dead center, all the material of the flange portion W3 flows into the vertical wall portion W2, and the molding portion W1 is connected to the molding surface 11 of the punch 10. It is sandwiched between the molding surface 21 of the die 20. As described above, the final molded product W ″ including the molding portion W1 along the shape of the molding surface 11 of the punch 10 and the vertical wall portion W2 extending downward from both ends in the width direction of the molding portion W1 is molded. . Note that it is not always necessary to allow all the material of the flange portion W3 to flow into the vertical wall portion W2, and the flange portion W3 may remain in the final molded product W ″.

  Thereafter, by raising the die 20, the blank holder 50 is raised by the pressure of the cylinder 52, and the final molded product W ″ placed on the blank holder 50 is taken out from the press molding apparatus 1 (not shown). At this time, the return slide surface 55 of the blank holder 50 is guided by the return guide surface 13 of the punch 10, and the blank holder 50 moves outward in the width direction while rising. When the return slide surface 55 of the blank holder 50 exceeds the return guide surface 13 of the punch 10, the blank holder 50 rises straight while the side surface 53 of the blank holder 50 and the side surface 12 of the punch 10 slide. As described above, the blank holder 50 is guided by the inclined surfaces (the return slide surface 55 and the return guide surface 13) provided on the blank holder 50 and the punch 10, so that the blank holder 50 can be removed without requiring a separate drive mechanism. It can be returned to the initial position.

  In the present embodiment, the pressure of the cylinder 52 that supports the blank holder 50, that is, the holder pressure of the blank holder 50 is kept constant during the above press forming. Thereby, it is not necessary to control the pressure of the cylinder 52, and the apparatus can be simplified.

  The present invention is not limited to the above embodiment. For example, the press molding apparatus 2 according to the second embodiment of the present invention shown in FIG. 7 changes the vertical wall portion from the flange portion W3 of the intermediate molded product W ′ by changing the holder pressure of the blank holder 50 by a control unit (not shown). It is different from the above embodiment in that the inflow of the material to W2 is promoted. Specifically, as shown in FIG. 7, the die 20 and the blank holder 50 sandwich both ends in the width direction of the metal plate W, and then the die 20 and the blank holder 50 are lowered to draw as shown in FIG. 8. To form an intermediate molded product W ′. When the die 20 and the blank holder 50 reach a predetermined position, the holder pressure of the blank holder 50 is reduced, for example, the holder pressure is set to zero. When the die 20 and the blank holder 50 are further lowered in this state, the flange portion W3 of the intermediate molded product W ′ is not constrained by the blank holder 50. Therefore, as shown in FIG. Material flows into the active area. Then, as shown in FIG. 10, when the blank holder 50 reaches the bottom dead center, all the material of the flange portion W3 flows into the vertical wall portion W2, and the final molded product W ′ composed of the molded portion W1 and the vertical wall portion W2. 'Is formed.

  By the way, in the press molding apparatus 1 which concerns on 1st Embodiment, since it is necessary to enable the blank holder 50 to move to the inflow direction (width direction inner side) of the material of the flange part W3, the blank holder 50 is set to the perimeter of the punch 10. FIG. For example, the blank holder 50 can be provided only on two opposite sides as shown in FIG. For this reason, as shown in FIG. 11, the press molding apparatus 1 can only mold the final molded product W ″ having a shape in which the vertical wall portions W <b> 2 are provided only on two opposite sides. On the other hand, according to the press molding apparatus 2 according to the second embodiment, the blank holder 50 may be moved up and down and does not need to be moved in the width direction. Accordingly, for example, a final molded product W ″ in which the vertical wall portion W2 is formed on the entire circumference as shown in FIG. 12 can also be molded. In this case, the blank holder 50 is provided on the entire circumference of the punch 10.

  In the above embodiment, the pressing surface 22 of the die 20 and the pressing surface 51 of the blank holder 50 are both planar. However, the present invention is not limited to this. For example, the pressing surface 22 and the pressing surface 51 are flanged. You may provide the bead which inhibits the inflow of the material from the part W3 to the vertical wall part W2. However, in the case of the press molding apparatus 1 (see FIG. 1) according to the first embodiment, it is necessary to provide a bead having a shape that can move the blank holder 50 inward in the width direction with respect to the die 20. Step beads as shown in FIG. 13 can be provided. Specifically, the pressing surface 22 of the die 20 and the pressing surface 51 of the blank holder 50 are provided with stepped portions 22a and 51a that are stepped down toward the outer side in the width direction (the right side in the figure), and the stepped portions 22a and 51a By sandwiching the metal plate W from above and below, the inflow of material from the flange portion W3 to the vertical wall portion W2 can be inhibited during drawing. Further, as shown in FIG. 14, when the blank holder 50 moves inward in the width direction (left side in the figure), the step portions 22a and 51a do not interfere with each other.

  In this case, since the stepped portion W4 is formed in the flange portion W3, the stepped portion W4 may remain on the vertical wall portion W2 of the final molded product W ″. In the present embodiment, the material of the flange portion W3 flows into the vertical wall portion W2 while being squeezed by the corner portion 24 between the pressing surface 22 and the side surface 23 of the die 20, and thus the stepped portion W4 may be lost. it can.

  In the above, as a measure for promoting the inflow of the material from the flange portion W3 to the vertical wall portion W2 of the intermediate molded product W ′, when the blank holder 50 is moved inward in the width direction (first embodiment), the holder Although the case of adjusting the pressure (second embodiment) has been described, the present invention is not limited to this. For example, the measures of the first embodiment and the second embodiment may be combined. That is, in FIG. 3 of the first embodiment, when the intermediate molded product W ′ reaches the molding limit point, the blank pressure of the blank holder 50 may be reduced and the blank holder 50 may be moved inward in the width direction. In this case, an effect of further promoting the inflow of the material from the flange portion W3 to the vertical wall portion W2 can be expected.

  Alternatively, in FIG. 8 of the second embodiment, when the intermediate molded product W ′ reaches the molding limit point, the blank holder 50 may be retracted all at once to the lowest lowered position. However, in this case, since the flange portion W3 is not supported from below, the material of the flange portion W3 may not smoothly flow into the vertical wall portion W2. Therefore, as shown in FIG. 9 of the second embodiment, even when the holder pressure is 0, it is preferable to allow the material of the flange portion W3 to flow into the vertical wall portion W2 while supporting the flange portion W3 from below with the blank holder 50. .

DESCRIPTION OF SYMBOLS 1 Press molding apparatus 10 Punch 11 Molding surface 12 Side surface 13 Return guide surface 20 Die 21 Molding surface 22 Press surface 23 Side surface 50 Blank holder 51 Press surface 52 Cylinder 53 Side surface 54 Slide surface 55 Return slide surface 56 Recess 60 Guide member 61 Guide surface W Metal plate W ′ Intermediate molded product W ″ Final molded product W1 Molded part W2 Vertical wall part W3 Flange part W4 Stepped part

Claims (2)

A press molding method using a press molding apparatus including a punch having a molding surface, and a die and a blank holder provided to be movable up and down with respect to the punch,
While holding both ends of the metal plate with the die and blank holder, lower the die, blank holder, and metal plate against the punch and press the metal plate against the punch forming surface along the punch forming surface. A step of forming an intermediate formed product having a formed part, a flange part sandwiched between a die and a blank holder, and a vertical wall part provided between the formed part and the flange part by drawing,
The die and the blank holder are further lowered beyond a predetermined position where the drawing is completed , the blank holder is lowered in a direction inclined with respect to the die lowering direction, and the blank holder is flanged in the intermediate molded product. Moving the material from the flange portion of the intermediate molded product to the vertical wall portion to promote the flow of the material from the flange portion of the intermediate molded product to the vertical wall portion, and molding the final molded product. Have
A guide member having a guide surface inclined so as to guide the blank holder in the inclined direction is provided below the blank holder,
The blank holder has a slide surface inclined so as to be guided by the guide surface of the guide member, and a return slide surface parallel to the slide surface,
The punch has a return guide surface inclined so as to guide the return slide surface of the blank holder,
When the blank holder descends in the inclined direction and moves in the material inflow direction from the flange portion to the vertical wall portion in the intermediate molded product, the slide surface of the blank holder and the return slide surface are the guide surface of the guide member. And press forming method to fit between the return guide surface of the punch . A punch having a molding surface, a die and a blank holder provided so as to be movable up and down with respect to the punch, and holding the die, the blank holder, and the metal plate with both ends of the metal plate sandwiched between the die and the blank holder By lowering the punch against the punch and pressing the metal plate against the punch forming surface, the forming portion formed along the punch forming surface, the flange portion sandwiched between the die and the blank holder, and the forming portion and the flange portion An intermediate molded product having a vertical wall provided between and is formed by drawing,
The blank holder is lowered to the predetermined position in the same direction as the die, and when it exceeds the predetermined position, the blank holder is lowered in a direction inclined with respect to the lowering direction of the die and the material flows from the flange portion to the vertical wall portion in the intermediate molded product. It is a press molding apparatus configured to form a final molded product by moving in a direction to promote the inflow of material from the flange portion of the intermediate molded product to the vertical wall portion than before the predetermined position,
A guide member having a guide surface inclined so as to guide the blank holder in the inclined direction is provided below the blank holder,
The blank holder has a slide surface inclined so as to be guided by the guide surface of the guide member, and a return slide surface parallel to the slide surface,
The punch has a return guide surface inclined so as to guide the return slide surface of the blank holder,
When the blank holder descends in the inclined direction and moves in the material inflow direction from the flange portion to the vertical wall portion in the intermediate molded product, the slide surface of the blank holder and the return slide surface are the guide surface of the guide member. Press molding device that fits between the punch and the return guide surface of the punch .

Images