JP4766921B2 - Hemming machine - Google Patents

Description

The present invention relates to a hemming apparatus and a method for manufacturing a hemming product for bending one metal plate of two metal plates stacked on each other to join the other metal plate to each other.

  For example, a peripheral part of a component configured by combining two metal plates (an outer panel and an inner panel) such as an automobile door panel and a bonnet is hemmed. A hemming apparatus for performing this hemming process moves an upper mold relative to a lower mold, and a hem punch provided on the upper mold moves a peripheral edge of one metal plate (outer panel) to the other metal plate (inner plate). The peripheral edges of the two metal plates are joined to each other by bending to the peripheral edge of the panel, and various proposals have been made so far (for example, see Patent Documents 1 to 3).

  Japanese Patent Application Laid-Open No. 2004-151867 discloses a hemming apparatus that hemmes a flange having a first part having a long bending length and a second part having a short bending length by a punch. And the second part is divided into second punch parts to be processed, and the second punch part protrudes below the first punch part and is supported by an elastic member, thereby preventing problems such as meandering of the parting line of the product. A technique for solving the problem is disclosed.

  Patent Document 2 discloses a configuration in which a movement trajectory during hemming of an integrated punch is minimized in a hemming processing apparatus in which a pre-hem punch and a main hem punch are integrated.

  Furthermore, Patent Document 3 is provided with a C-shaped frame that can move in the direction of contact with and away from the workpiece, and the hem die is raised with the C-shaped frame and the pre-hem punch advanced, and the pre-hem with respect to the flange of the outer panel. A hemming processing apparatus is disclosed in which the hem die is lifted again and the final hemming is performed with the hem punch in a state where the pre-hem punch is retracted following the processing of the hem die.

JP-A-5-104159 JP 2004-181498 A JP 2004-337984 A

  By the way, particularly when two metal plates (outer panel and inner panel) having a rectangular shape are hemmed, there is a problem that the corner portion of the outer panel is lifted unless the corner portion is pressed, and the product surface quality and appearance are deteriorated.

  Therefore, conventionally, a method has been adopted in which the corner portion is processed at a different timing from the straight portion. However, this method is inefficient due to a long cycle time and requires a mechanism for adjusting the timing. However, there is a problem that the apparatus becomes complicated and expensive.

  It is also proposed to provide a dedicated device for pressing the corner portion of the outer panel during hemming.

  However, if a dedicated device is provided, the hemming processing device becomes complicated and large, and requires a large space for its installation. In addition to being able to handle hemming processing of small automobile parts, it is difficult to design, manufacture, and standardize the device. There is a problem that costs increase.

  Further, Patent Documents 1 to 3 do not disclose any countermeasures against the problem of the outer panel floating during hemming.

The present invention has been made in view of the above-mentioned problems, and the target processing is hemming that can improve the product surface quality and appearance of the corner portion without increasing the complexity and cost of the structure. An object of the present invention is to provide an apparatus and a method for manufacturing a hemming processed product .

In order to achieve the above object, the invention according to claim 1 is the peripheral flange of the first metal plate and the second metal plate each having the upper die moved relative to the lower die and each having a corner portion and a straight portion. In the hemming processing device that connects the parts to each other,
Both metals are provided by bending the peripheral flange portion bent at a right angle in the straight portion of the first metal plate on the inner peripheral side and overlapping the peripheral flange portion of the second metal plate. A peripheral hem flange portion bent at a right angle in a corner portion of the first metal plate in conjunction with a relative movement of the upper hem punch and a main hem punch for performing a main hem processing for connecting peripheral edges of the plates to the inner peripheral side. A corner pressing device integrated with the upper die after being bent and pressed by a predetermined angle , and pressing the peripheral flange portion of the corner portion of the first metal plate by the corner pressing device hold, said peripheral flange of said predetermined angle to the while still folded first straight portion the hemming completed before the start of Purihemu processing in the peripheral flange portion of the metal plate Wherein the hemming apparatus which is characterized in that up.

  According to a second aspect of the present invention, in the first aspect of the present invention, the corner pressing device is a corner pressing punch that is slidably held with respect to the upper mold, and a force proportional to the movement stroke of the upper mold. A pressure source for pressing the corner pressing punch is included.

  The invention according to claim 3 is the invention according to claim 2, wherein the pressure source is constituted by a gas cushion or an elastic body.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a prehem punch for performing prehem processing as a pre-process of the main hem processing by the main hem punch is provided in the lower mold. Features.

Invention of Claim 5 is the manufacturing method of the hemming processed product which couple | bonds the periphery of the 1st metal plate and 2nd metal plate which each have a corner part and a straight part,
A corner bending step of overlapping the first metal plate on the second metal plate and bending the peripheral flange portion bent at a right angle in the corner portion of the first metal plate to the inner peripheral side by a predetermined angle;
The peripheral flange portion at the corner portion of the first metal plate is made to be bent at a predetermined angle by the corner bending step before the start of the prehem processing at the peripheral flange portion of the straight portion of the first metal plate. A corner pressing process for pressing and holding until the completion of the hem processing ;
A prehem step of bending the peripheral flange portion of the straight portion of the first metal plate to the inner peripheral side by a predetermined angle while maintaining the corner pressing step in the peripheral flange portion of the corner portion of the first metal plate;
Folding the peripheral flange portion of the straight portion of the first metal plate bent in the pre-hem step further to the inner peripheral side while maintaining the corner pressing step in the peripheral flange portion of the corner portion of the first metal plate, And a hemming step for superimposing on the peripheral flange portion of the second metal plate.

  According to the first to third aspects of the present invention, the corner of the first metal plate is pressed by the corner pressing device in conjunction with the relative movement of the upper mold. During the hemming process in which the metal plates are folded around the periphery of the metal plate and joined together, the corner of the first metal plate is prevented from being lifted, and the product surface quality and appearance of the corner are improved. Since the corner pressing device is integrated into the upper die without being separately provided, the structure of the hemming device is not complicated and the cost is not increased.

  According to the invention described in claim 4, since the pre-hem processing is performed by the pre-hem punch prior to the main hem processing, the subsequent main hem processing can be performed smoothly and stably.

According to the invention described in claim 5 , since the pressing of the peripheral flange portion of the corner portion of the first metal plate is performed from the start of the prehem processing to the completion of the main hem processing, the prehem processing and the main hem processing are performed. preventing floating of the first metal plate can increase the product surface quality and appearance of the corner portion.

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

  FIG. 1 is a plan view of a lower mold of the hemming apparatus according to the present invention, FIG. 2 is a plan view of an upper mold of the hemming apparatus, and FIG. 3 is a partial sectional view showing a machining process in a corner portion. (B) shows the state when the pre-hem processing is completed, and (c) shows the state when the main hem processing is completed. FIG. 4 is a partial cross-sectional view showing a machining process in a straight part other than the corner part. (A) is when corner pressing is started, (b) is when pre-hem processing is completed, and (c) is when this hem processing is completed. Each state is shown. 5 is an enlarged detail view of part A in FIG. 3 (a), FIG. 6 (a) is an enlarged detail view of part B in FIG. 4 (a), and FIG. 6 (b) is an enlarged view of part C in FIG. FIG. 6C is a detailed view, and FIG. 4C is an enlarged detailed view of a D portion in FIG.

  A lower mold 1 shown in FIG. 1 includes a rectangular block-shaped punch 2, and a pair of prehem punches 3 along a short side and a pair of prehem punches 3 along a long side are arranged around the corner of the punch 2 except for a corner portion. ing. One link cam 5 is connected to each prehem punch 3 on the short side, and two link cams 5 are connected to each prehem punch 3 on the long side.

  Further, the bottomed blocks 6 are respectively arranged outside the corner portions of the punch 2.

  On the other hand, the upper die 11 shown in FIG. 2 is located above the lower die 1 and moves up and down with respect to the lower die 1 by a driving means (not shown). The cam driver 13 is arranged at a position corresponding to the link cam 5 around the hem punch 12. A rectangular block-shaped pad 14 is disposed inside the hem punch 12.

  Here, the configuration of the prehem punch 3, the link cam 5, and the cam driver 13 will be described with reference to FIG.

  The prehem punch 3 provided on the lower mold 1 side is formed with a tapered surface 3a having an inclination angle of about 45 ° on the side facing the punch 2 along the direction perpendicular to the paper surface of FIG. 3 is supported so as to be pivotable up and down about a shaft 7. A roller 8 is rotatably supported above the shaft 7 on the side surface of the pre-hem punch 3, and the pre-hem punch 3 is attached to the shaft 7 by a spring 9 that is compressed between the pre-hem punch 3 and the link cam 5. The center is biased upward (counterclockwise in FIG. 4).

  Further, the cam driver 13 provided on the upper die 11 side has a sloped cam surface 13a for rotating the prehem punch 3 in the clockwise direction in FIG. 4 and the prehem punch 3 in the counterclockwise direction in FIG. An inclined cam surface 13b is formed.

  Incidentally, as shown in FIG. 2, convex portions 12a having a semicircular shape in plan view are formed at the corner portions of the hem punch 12, and corner pressing devices 20 are integrally incorporated into the respective convex portions 12a. Yes.

  Here, the detail of a structure of the corner pressing device 20 is demonstrated based on FIG.

  The corner pressing device 20 includes a gas cushion 24 as a pressure source, and a lower end of a rod 21 extending downward from the gas cushion 24 is slidable in a guide hole 12b formed in the hem punch 12. It is connected to the inserted guide pin 22. A corner pressing punch 23 is attached to a lower end portion of the guide pin 22 that extends downward from the main hem punch 12. A stopper 15 for restricting the downward movement of the upper mold 11 is attached to the lower surface of the hem punch 12.

  The gas cushion 24 is configured by binding a piston (not shown) to the upper end of the rod 21 inserted into the cylinder 25 from below and enclosing gas in a gas chamber defined in the cylinder 25 by the piston. Has been.

  The corner pressing punch 23 has an inclined tapered surface 23a.

  Next, hemming by the hemming apparatus configured as described above will be described with reference to FIGS.

  Hemming is performed in the following order: 1) start of corner pressing, 2) pre-hem processing, and 3) main hem processing.

1) Corner presser start:
In the hemming process, as shown in the figure, a rectangular outer panel W1 and an inner panel W2 are set on the punch 2 of the lower mold 1 with their peripheral edges overlapped. More specifically, as shown in part of FIG. 6A, the outer panel W1 has a peripheral flange portion W1a bent at a right angle, and the inner panel W2 is formed on the outer panel W1. Flat peripheral flange portions W2a are stacked, and the outer panel W1 and the inner panel W2 except for the peripheral flange portions W1a and W2a are pressed onto the punch 2 by the pad 14 and fixed.

  Thus, when the upper die 11 starts to descend from the top dead center by a driving means (not shown), the corner pressing device 20 integrally incorporated in the corner portion of the upper die 11 is also lowered integrally. When the punch 23 comes into contact with the bottomed block 6, as shown in FIG. 3A, the corner portion of the peripheral flange portion W1a of the outer panel W1 is pressed by the corner pressing punch 23, as shown in detail in FIG. Further, the corner portion of the peripheral flange portion W1a of the outer panel W1 is bent inward by a predetermined angle by the tapered surface 23a of the corner pressing punch 23. Note that the bending angle of the corner portion of the peripheral flange portion W1a at this time differs depending on the size of R of the corner portion, and the bending angle is adjusted by adjusting the height of the corner pressing punch 23.

  At this time, as shown in FIG. 4A, the pre-hem punch 3 is urged counterclockwise about the shaft 7 by the spring 9, but the roller 8 supported by this is the cam surface of the cam driver 13. By being engaged with 13a, it is held in a state of being separated from the outer panel W1. Therefore, at the time when pressing of the corner portion of the peripheral flange portion W1a of the outer panel W1 is started, no processing is performed on the straight portion except the corner portion of the peripheral flange portion W1a of the outer panel W1.

2) Prehem processing:
As described above, when the upper mold 11 is further lowered as shown in FIG. 3B after pressing by the corner pressing punch 23 at the corner portion of the peripheral flange W1a of the outer panel W1 is started, in the corner pressing device 20 The rod 21 of the gas cushion 24 and the piston (not shown) attached to the tip of the gas cushion 24 remain stationary when the pressure in the gas chamber is low, and only the cylinder 25 is lowered together with the upper mold 11. For this reason, the gas sealed in the gas chamber in the cylinder 25 is compressed to increase the pressure in the gas chamber, and the reaction force is transmitted to the corner pressing punch 23 via the piston and the guide pin 22, so that the peripheral flange of the outer panel W 1 The corner portion of the portion W1a is pressed by the corner pressing punch 23 with a stronger force. As described above, the gas cushion 24 generates a pressing force proportional to the lowering stroke of the upper mold 11, and an elastic body such as rubber can be used as such a pressure source.

  When the upper die 11 is lowered as described above, the cam surface 13a of the cam driver 13 is engaged with the roller 8 of the prehem punch 3 as shown in FIG. 6B, the straight portion excluding the corner portion of the peripheral flange portion W1a of the outer panel W1 is formed from the right angle shown in FIG. 6A by the tapered surface 3a of the pre-hem punch 3, as shown in detail in FIG. It is bent inward by a predetermined angle (pre-hem processing). FIG. 3B shows a state when the pre-hem processing is completed.

3) This hem processing:
When the upper die 11 is further lowered from the state shown in FIG. 3B, the roller 8 of the prehem punch 3 is engaged with the cam surface 13b of the cam driver 13 as shown in FIG. The spring 9 is rotated counterclockwise about the shaft 7 by the urging force of the spring 9 and is separated from the outer panel W1.

  Thereafter, as shown in FIGS. 3C and 4C, when the upper die 11 reaches the bottom dead center, the peripheral flange portion W1a of the outer panel W1 has a corner pressing punch of the corner pressing device 20. The straight part excluding the corner part, that is, the straight part that has been bent in advance by the pre-hem processing, is bent inward by the main hem processing by the main hem punch 12 while being pressed at a predetermined pressure by 23, as shown in FIG. Thus, this straight part is overlapped on the peripheral flange part W2a of the inner panel W2, and both panels W1 and W2 are joined at the peripheral flange parts W1a and W2a, and a series of hemming processes is completed.

  In the above hemming process, the corner peripheral edge of the peripheral flange W1a of the outer panel W1 is pressed by the corner pressing punch 23 of the corner pressing device 20 in conjunction with the lowering of the upper mold 11, and this pressing is performed before the start of the prehem processing. Since this hem processing is completed, the corner portion of the peripheral flange portion W1a of the outer panel W1 is prevented from being lifted at the time of pre-hem processing for bending the straight portion of the peripheral flange portion W1a of the outer panel W1 inward and during the main hem processing. Product surface quality and appearance are improved.

  And according to the prehem processing apparatus which concerns on this Embodiment, since this was integrated in the corner part of this hem punch 12 of the upper mold | type 11 without providing the corner pressing device 20, the said hemming processing apparatus The structure is complicated and the cost is not increased.

  In the present embodiment, since the pre-hem processing is performed by the pre-hem punch 3 prior to the main hem processing, the subsequent main hem processing can be performed smoothly and stably.

  The present invention is suitable for hemming processing on a metal plate having a corner portion such as a rectangular plate-shaped metal plate.

It is a top view of the lower mold | type of the hemming processing apparatus which concerns on this invention. It is a top view of the upper mold | type of the hemming processing apparatus which concerns on this invention. It is a fragmentary sectional view showing the processing process of the corner part by the hemming processing device concerning the present invention, (a) at the time of corner press start, (b) at the time of completion of prehem processing, (c) at the time of completion of this hem processing Respectively. It is a fragmentary sectional view which shows the process of straight parts other than a corner part by the hemming processing apparatus which concerns on this invention, (a) at the time of a corner press start, (b) at the time of completion of prehem processing, (c) is this hemming. Each state when completed. It is the A section enlarged detail drawing of Drawing 3 (a). 4A is an enlarged detailed view of a portion B in FIG. 4A, FIG. 4B is an enlarged detailed view of a portion C in FIG. 4B, and FIG. 4C is an enlarged detailed view of a portion D in FIG.

Explanation of symbols

1 Lower mold 2 Punch 3 Pre-hem punch 5 Link cam 6 Bottom block 11 Upper mold 12 Hem punch 13 Cam driver 14 Pad 15 Stopper 20 Corner pressing device 21 Rod 22 Guide pin 23 Corner pressing punch 24 Gas cushion 25 Cylinder W1 Outer panel Metal plate)
W1a Outer panel peripheral flange W2 Inner panel (second metal plate)
W2a Inner panel peripheral flange

Claims (5)

In the hemming apparatus for moving the upper mold relative to the lower mold and mutually connecting the peripheral flange portions of the first metal plate and the second metal plate each having a corner portion and a straight portion,
Both metals are provided by bending the peripheral flange portion bent at a right angle in the straight portion of the first metal plate on the inner peripheral side and overlapping the peripheral flange portion of the second metal plate. This hem punch that performs this hem processing to join the peripheral edges of the plate,
In conjunction with the relative movement of the upper die, the peripheral flange portion bent at a right angle in the corner portion of the first metal plate is bent toward the inner peripheral side by a predetermined angle , and then pressed and held. A corner pressing device integrated into the unit,
Pressing and holding the peripheral flange portion of the corner portion of the first metal plate by the corner pressing device, the peripheral flange portion of the straight portion of the first metal plate while the peripheral flange is bent at the predetermined angle. A hemming apparatus that performs the process from the start of pre-hem processing to the completion of main hem processing.   The corner pressing device includes a corner pressing punch that is slidably held with respect to the upper mold, and a pressure source that presses the corner pressing punch with a force proportional to the movement stroke of the upper mold. The hemming processing apparatus according to claim 1, wherein:   The hemming processing apparatus according to claim 2, wherein the pressure source is formed of a gas cushion or an elastic body.   The hemming processing apparatus according to any one of claims 1 to 3, wherein a prehem punch for performing prehem processing before the main hem processing is provided in the lower mold. In the method of manufacturing a hemming product, in which the peripheral edges of the first metal plate and the second metal plate each having a corner portion and a straight portion are coupled,
A corner bending step of overlapping the first metal plate on the second metal plate and bending the peripheral flange portion bent at a right angle in the corner portion of the first metal plate to the inner peripheral side by a predetermined angle;
The peripheral flange portion at the corner portion of the first metal plate is made to be bent at a predetermined angle by the corner bending step before the start of the prehem processing at the peripheral flange portion of the straight portion of the first metal plate. A corner pressing process for pressing and holding until the completion of the hem processing ;
A prehem step of bending the peripheral flange portion of the straight portion of the first metal plate to the inner peripheral side by a predetermined angle while maintaining the corner pressing step in the peripheral flange portion of the corner portion of the first metal plate;
Folding the peripheral flange portion of the straight portion of the first metal plate bent in the pre-hem step further to the inner peripheral side while maintaining the corner pressing step in the peripheral flange portion of the corner portion of the first metal plate, And a hemming step of superimposing on the peripheral flange portion of the second metal plate.

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