JP2016155158A - Hemming processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form uniformly and accurately a bead shape formed on a marginal part of a workpiece.SOLUTION: A hemming processing method includes a press process for forming a bending part W6 on a marginal part of a workpiece W, and a hemming process for applying a hemming processing to the bending part W6 after the press process, to be thereby deformed into a bead shape. In the press process, a thin wall part W3 having a thinner wall than other part is formed on a part of the bending part W6.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a hemming method for processing, for example, an edge of a steel plate into a bead shape.

  For example, an outer plate member of an automobile such as a hood or a door is subjected to a hemming process at an end portion from the viewpoint of appearance and strength. This hemming process can be performed by a roller hemming device as disclosed in Patent Document 1 below, for example.

  The roller hemming device includes a large-diameter roller that preliminarily bends the flange portion of the workpiece, and a small-diameter roller that performs a main bend on the flange portion of the workpiece that has been preliminarily bent. The roller hemming device uses a large-diameter roller to pre-bend the flange portion at a predetermined bending angle, and further uses a small-diameter roller so that the flange portion contacts the inner panel overlaid on the outer panel. Then, the main bending is performed to bend the flange portion.

  The flange portion bent by each roller is bent while maintaining its linear shape in the preliminary bending and the main bending.

JP2013-233562A

  By the way, in the hemming process, in addition to the case where the flange part is processed in a straight shape as described above, the flange part may be processed into a bead shape that is substantially circular in cross section. In order to process the flange part into a bead shape, it is difficult to perform uniform and accurate processing because the shape is more complex than when processing while maintaining the linear shape. .

  Then, an object of this invention is to provide the hemming processing method which can shape | mold the edge shape formed in the edge part of a workpiece | work uniformly and accurately.

  The present invention is for solving the above-described problems, and a pressing step for forming a bent portion at an end portion of a workpiece, and after the pressing step, the bent portion is subjected to hemming to be deformed into a bead shape. A thinning portion that is thinner than other portions in a part of the bent portion in the pressing step.

  According to such a configuration, by forming the thin portion in a part of the bent portion in the pressing process, the thin portion is deformed in preference to the other portion in the hemming process. That is, the bent part always starts deformation by hemming at a fixed position (position of the thin part). Thereby, the bead shape formed by deforming the bent portion becomes uniform and accurate.

  As described above, according to the present invention, the bead shape formed on the edge portion of the workpiece can be formed uniformly and accurately.

It is sectional drawing which shows a drawing apparatus. FIG. 6 is a cross-sectional view showing a state in the middle of a first press process by a drawing apparatus. It is sectional drawing which shows the state at the time of completion | finish in the 1st press process by a drawing apparatus. It is sectional drawing for demonstrating the 2nd press process of the workpiece | work by an edge part processing apparatus. It is sectional drawing for demonstrating the hemming process by a hemming apparatus. (A) A figure shows the state before a process, (b) A figure shows the state at the time of completion | finish of a process.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  1 to 3 show a drawing apparatus for drawing a workpiece. FIG. 4 shows an end processing apparatus for processing the end (edge) of the workpiece after the drawing. FIG. 5 shows a hemming processing device that deforms a bent portion formed at an end portion of a workpiece to process it into a bead shape. Prior to describing the hemming method according to the present invention, the configuration of each of these devices will be described below.

  As shown in FIGS. 1 to 3, the drawing apparatus 1 includes a punch 2, a die 3 that can be raised and lowered with respect to the punch 2, and a lift 3 that can be raised and lowered with respect to the punch 2. And a blank holder 4 for working and clamping the end of the workpiece W.

  The punch 2 includes a molding surface 5 formed on the upper surface, a first shoulder 6 connected to the molding surface 5, a first vertical wall 7 connected to the first shoulder 6, and the first vertical wall 7. And a second shoulder 9 connected to the horizontal wall 8 and a second vertical wall 10 connected to the second shoulder 9.

  The molding surface 5 is for forming a predetermined shape on the center portion of the workpiece W together with a part of the die 3. The first shoulder 6 is formed between the molding surface 5 and the first vertical wall 7 and is configured as a curved surface having a predetermined radius of curvature. The first vertical wall portion 7 has an inclined surface that is inclined at a predetermined angle with respect to the vertical direction. The wall surface of the horizontal wall portion 8 is configured as a horizontal surface in the present embodiment, but may be an inclined surface inclined with respect to the horizontal direction. The boundary portion 11 between the first vertical wall portion 7 and the horizontal wall portion 8 is R-chamfered and is a concave curved surface having a predetermined radius of curvature. The second shoulder portion 9 is formed between the horizontal wall portion 8 and the second vertical wall portion 10 and is configured as a curved surface having a predetermined radius of curvature. The second vertical wall portion 10 has an inclined surface that is inclined at a predetermined angle with respect to the vertical direction.

  The die 3 is configured to be movable up and down by a drive unit (cylinder or the like) (not shown). The die 3 includes a molding surface 12 corresponding to the molding surface 5 of the punch 2, a first vertical wall portion 13 connected to the molding surface 12, and a first shoulder portion 14 connected to the lower end portion of the first vertical wall portion 13. And the horizontal wall 15 connected to the first shoulder 14, the second vertical wall 16 connected to the horizontal wall 15, the second vertical wall 16 connected to the second vertical wall 16, and the work W in cooperation with the blank holder 4. And a pressing surface 17 that presses the end portion.

  The molding surface 12 of the die 3 is configured in a concave shape corresponding to the convex shape of the molding surface 5 of the punch 2. The first vertical wall portion 13 has an inclined surface that is inclined at a predetermined angle with respect to the vertical direction. The first vertical wall portion 13 is for forming a part of the workpiece W together with the first vertical wall portion 7 of the punch 2 when the workpiece W is processed. The first shoulder portion 14 is formed between the first vertical wall portion 13 and the horizontal wall portion 15 and is configured as a curved surface having a predetermined radius of curvature. The wall surface of the horizontal wall portion 15 is configured as a horizontal surface in the present embodiment, but may be an inclined surface inclined with respect to the horizontal direction. The second vertical wall portion 16 has an inclined surface that is inclined at a predetermined angle with respect to the vertical direction.

  The pressing surface 17 of the die 3 protrudes below the molding surface 12. The pressing surface 17 has a recess 18 with which a part of the blank holder 4 is engaged.

  The blank holder 4 has a pressing surface 19 that presses the end portion of the workpiece W in cooperation with the pressing surface 17 of the die 3 and is supported from below by a support portion (for example, a cylinder) not shown so as to be lifted and lowered. On the pressing surface 19 of the blank holder 4, a protrusion 20 is formed that engages with a recess 18 formed on the pressing surface 17 of the die 3. In addition, the blank holder 4 can adjust the holder pressure (force for clamping the workpiece W), and in this embodiment, the holder pressure of the blank holder 4 can be adjusted by adjusting the pressure of the cylinder.

  As shown in FIG. 4, the end processing device 21 (bending press device) includes an upper die 22 that can be raised and lowered, a lower die 23 that supports the workpiece W, and a support pad 24 that holds the workpiece W together with the lower die 23. Is mainly provided. The upper die 22 has a bending blade 25 and contacts a part of the workpiece W to perform a predetermined bending process. The lower mold 23 has a pressing surface 26 for holding the workpiece W together with the support pad 24. The support pad 24 is configured to be movable up and down and has a pressing surface 27 that presses the workpiece W.

  As shown in FIG. 5, the hemming device 28 mainly includes a lower mold 29 on which the workpiece W is placed, and a roller 30 that hemmes the end portion of the workpiece W. The lower mold 29 has a receiving surface 31 that receives the workpiece W. The workpiece W is placed on the receiving surface 31 and is fixed to the lower mold 29 by a clamping mechanism (not shown). The roller 30 is guided in a predetermined direction by a guide mechanism (not shown), and presses the end of the workpiece W to be deformed into a predetermined bead shape.

  Hereinafter, the hemming method of the workpiece W according to the present invention will be described. In the following description, a case where a single steel plate is processed as a workpiece W will be described.

  The workpiece W is processed into a bead shape through a pressing process performed by the drawing apparatus 1 and the end processing apparatus 21 and a hemming process performed by the hemming apparatus 28. The pressing process includes a first pressing process by the drawing apparatus 1 and a second pressing process by the edge processing apparatus 21.

  In the first pressing step, first, the end portion (edge portion) of the workpiece W is clamped by the pressing surface 17 of the die 3 and the pressing surface 19 of the blank holder 4. At this time, the protrusion 20 on the pressing surface 19 of the blank holder 4 is fitted into the recess 18 on the pressing surface 17 of the die 3. Thereby, a part of workpiece | work W is clamped firmly. In this state, the die 3 is further pressed downward, and when this pressure exceeds the pressure of the cylinder in the blank holder 4, the die 3, the blank holder 4, and the work W are lowered together, and the work W is drawn. Starts.

  When the workpiece W is lowered together with the die 3 and the blank holder 4, the workpiece W first contacts the forming surface 5 of the punch 2. When the workpiece W is further lowered while being molded by the molding surface 5, the first shoulder 14 of the die 3 comes into contact with a part of the workpiece W as shown in FIG. At this time, the pressing surface 17 of the die 3 and the pressing surface 19 of the blank holder 4 firmly hold the workpiece W by the fitting of the concave portion 18 and the protruding portion 20. The portion does not flow into the center in the width direction (molding surface 5 side).

  The workpiece W further descends while being pressed by the molding surface 5 of the die 3 and the first shoulder 14. When the die 3 is further lowered and the die 3 and the punch 2 are completely fitted as shown in FIG. 3, the drawing process by the drawing apparatus 1 is completed.

  Accordingly, the workpiece W is formed by the molding surface W1 of the punch 2 and the molding surface 12 of the die 3, the first vertical wall portion 7 of the punch 2, and the first vertical wall portion 13 of the die 3. The flange portion W4 formed by the first wall portion W2 formed by the first shoulder portion 14 of the die 3, the thin wall portion W3 formed by the first shoulder portion 14 of the die 3, and the wall portion 8 of the punch 2 and the wall portion 15 of the die 3. And a second vertical wall W5 formed by the second vertical wall 10 of the punch 2 and the second vertical wall 16 of the die 3.

  When this first pressing step is completed, the workpiece W is cut into a predetermined size. In the present embodiment, the workpiece W is removed from the drawing apparatus 1 and cut along a trim line (TL) shown in FIG. 3 (cutting step). The trim line TL is set in the middle of the flange portion W4 of the workpiece W. Therefore, when the cutting is performed based on the trim line TL, the workpiece W is cut in the middle portion of the flange portion W4, whereby the workpiece W is formed into the forming portion W1, the first vertical wall portion W2, and the thin portion W3. And a part of the flange portion W4.

  Thereafter, as shown in FIG. 4, a second pressing process is performed on the workpiece W. In the second pressing step, the molding part W1 of the workpiece W is sandwiched between the lower mold 23 and the support pad 24 in the end machining apparatus 21, and the upper mold 22 is lowered to perform the bending process of the workpiece W. When the upper die 22 is lowered, the bending blade 25 comes into contact with the flange portion W4 of the workpiece W. When the flange portion W4 is pressed by the bending blade 2, the flange portion W4 is deformed so as to be in the same direction as the first vertical wall portion W2 of the workpiece W (to face downward).

  Since the thin portion W3 of the workpiece W is formed at the boundary portion between the first vertical wall portion W2 and the flange portion W4, when the flange portion W4 is pressed by the bending blade 25 of the upper mold 22, the flange portion It deform | transforms so that W4 may face downward. As a result, the flange portion W4 disappears integrally with the first vertical wall portion W2, and the first vertical wall portion W2 becomes integral with the flange portion W4, thereby forming a predetermined angle with respect to the molding portion W1. A bent portion W6 is formed.

  The bent portion W6 formed on the workpiece W by the second pressing step is configured in a straight line and has a thin portion W3 in the middle thereof. The thin portion W3 is formed thinner than the other portions, that is, the portion that was the first vertical wall portion W1 and the portion that was the flange portion W4. The thin portion W3 is configured such that the central portion is the thinnest and gradually becomes thinner from both ends toward the central portion.

  As described above, when the bent portion W6 is formed in the workpiece W in the pressing process, the process proceeds to the hemming process. In the hemming process, as shown in FIG. 5A, the forming portion W1 of the workpiece W is placed on the receiving surface 31 of the lower mold 29. At this time, the bent portion W6 stands up from the molding portion W1. In this state, the workpiece W is fixed to the lower mold 29 via the clamp mechanism. Thereafter, hemming processing by the roller 30 is performed on the bent portion W6.

  At this time, when the roller 30 presses the bent portion W6, first, the thin-walled portion W3 that is easily deformed has priority over the other portions (the portion that was the first vertical wall portion W1 and the portion that was the flange portion W4). Will be transformed. That is, in this hemming process, the thin-walled portion W3 starts to be deformed, and thereafter the bent portion W6 is bent as a whole. As shown in FIG. 5B, the bent portion W <b> 6 is finally deformed into a bead shape (ball edge portion) by the pressing of the roller 30. Thus, the machining of the workpiece W is completed.

  According to the present invention described above, by forming the thin portion W3 in a part of the bent portion W6 in the pressing process, the thin portion W3 has priority over other portions in the hemming process. Will be transformed. That is, the bent portion W6 always starts to be deformed by hemming at a fixed position (position of the thin portion W3). Therefore, the bead shape formed by deforming the bent portion W6 is uniform and accurate. Also in the second pressing step, the bent portion 6 can be easily formed by deforming the thin-walled portion W3 with priority over other portions.

  In addition, the hemming processing method which concerns on this invention is not limited to the structure of the said embodiment. Further, the hemming processing method according to the present invention is not limited to the above-described effects. The hemming processing method according to the present invention can be variously modified without departing from the gist of the present invention.

  In the above-described embodiment, an example in which the workpiece W including one panel is processed has been described. However, the present invention is not limited thereto, and the present invention can be applied to a case where two or more panels are used as the workpiece W.

  In the above embodiment, the hemming process using the roller 30 is illustrated, but the present invention is not limited to this, and a bead shape may be formed on the edge of the workpiece W by hemming with a die and a punch.

1 Drawing processing device 21 End processing device 28 Hemming processing device W Work W3 Thin portion

Claims (1)

A pressing step of forming a bent portion at the end of the workpiece;
And a hemming process step of performing a hemming process on the bent part and deforming it into a bead shape after the pressing process,
A hemming method according to claim 1, wherein in the pressing step, a thin portion that is thinner than other portions is formed in a part of the bent portion.

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