JP2023015529A - Press product manufacturing method and burring device - Google Patents

Abstract

To perform a burring caulking process and another process (molding process) by one metal mold.SOLUTION: Two metal plates 10, 11 are overlapped and molded, and the metal plates 10, 11 are coupled by burring caulking. The overlapped two metal plates 10, 11 are pinched by an upper die 3 and a lower die 4 of a metal mold 2 to be molded into a target shape. After the process, a burring punch 6 located on the lower die 4 is moved forward toward the metal plates 10, 11 by drive of a cam mechanism 20 synchronous with operation of the metal mold 2, and the burring punch 6 forms a burring part 10i on the metal plates 10, 11. After the process, the burring punch 6 is retracted from the metal plates 10, 11 by drive of the cam mechanism 20. After the process, a caulking punch 5 located on the upper die 3 is moved forward toward the metal plates 10, 11, and the caulking punch 5 bends a tip of the burring part 10i outward to form a caulking part 10j.SELECTED DRAWING: Figure 4

Description

The present invention relates to a press product manufacturing method and a burring device.

As a technique for joining two steel plates (metal plates), there is a burring caulking method disclosed in Patent Documents 1 and 2, for example. In the technique described in Patent Document 1, first, one steel plate is subjected to burring processing, the other steel plate on the other side is subjected to hole processing, a hole is passed through the cylindrical portion of the burring, and the tip of the burring is extended in the outer circumferential direction. The two steel plates are joined by bending or crushing them (crimping).

The technique described in Patent Document 1 performs burring and crimping (burring and crimping) in a plurality of steps (a plurality of molds). On the other hand, the technique described in Patent Document 2 performs burring caulking with one mold. The technique described in Patent Document 2 includes an upper die having a burring punch, a lower die having a cushion base (die) movable by a cushion device, and a winding punch (crimping punch) driven by a cam mechanism. , the bent portion of the burring hole is rolled (crimped) by a crimping punch.

JP 2006-312194 A Japanese Utility Model Laid-Open No. 61-49629

Press-formed products used as automobile body parts are formed into various shapes depending on the purpose. For this reason, the number of steps tends to increase, but efforts are being made to reduce the number of steps from the viewpoint of productivity. In other words, different processes are performed in one process using one mold to reduce the number of processes. The technique described in the above-mentioned Patent Document 2 can perform burring crimping with one die, but the press machine requires a cushion device, and the lower die is movable (movable), so other processes (especially , molding process).

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a press product manufacturing method and a burring apparatus that can perform a burring crimping process and another process (forming process) using a single mold. do.

One aspect of the present invention is a method of manufacturing a pressed product in which two metal plates are superimposed and molded, and the metal plates are joined by burring and caulking. The manufacturing method includes a molding process in which two metal plates are sandwiched between a movable mold and a fixed mold to form a desired shape, and after the molding process, a synchronous operation synchronized with the movement of the movable mold. A burring process in which a burring punch arranged in a fixed mold is moved forward toward a metal plate by driving the mechanism to form a burring portion on the metal plate by the burring punch, and after the burring process, a synchronous operation mechanism is driven to perform the burring process. , a burring punch retreating step of retreating the burring punch from the metal plate, and after the burring punch retreating step, the crimping punch arranged in the movable die is moved forward toward the metal plate, and the tip of the burring portion is moved outward by the crimping punch. and a crimping step of forming a crimped portion by bending it.

One aspect of the present invention is a burring device that superimposes two metal plates and performs molding and burring and crimping. The burring apparatus includes a mold having a movable mold and a fixed mold, a crimping punch arranged in the movable mold, a burring punch arranged in the fixed mold, and a cam mechanism driven in synchronization with the movement of the movable mold. , provided. The cam mechanism advances the burring punch toward the metal plate in synchronization with the operation of the movable die, forms a burring portion on the metal plate with the burring punch, and moves the burring punch backward from the metal plate. Later, the crimping punch is moved forward toward the metal plate, and the tip of the burring portion is bent outward by the crimping punch to form the crimping portion.

According to the method for manufacturing a pressed product and the burring device according to one aspect of the present invention, the step of performing burring and caulking and another step (forming step) can be performed with one mold.

It is explanatory drawing of the burring crimping process in the manufacturing method which concerns on this embodiment. It is explanatory drawing of the burring crimping process in the manufacturing method which concerns on this embodiment. It is explanatory drawing of the burring crimping process in the manufacturing method which concerns on this embodiment. It is explanatory drawing of the burring crimping process in the manufacturing method which concerns on this embodiment. It is explanatory drawing of the burring caulking process which expands and shows the hole formed in material. It is explanatory drawing of the burring caulking process which expands and shows the hole formed in material. It is explanatory drawing of the burring caulking process which expands and shows the hole formed in material. 1 is a schematic front cross-sectional view of a burring device according to this embodiment; FIG. 1 is a schematic front cross-sectional view of a burring device according to this embodiment; FIG. 1 is a schematic side cross-sectional view of a burring device according to this embodiment; FIG. It is a figure which shows the outline|summary of the cam mechanism which concerns on this embodiment. FIG. 4 is an explanatory diagram of a burring process included in the manufacturing process according to the embodiment; It is explanatory drawing of the burring process which expands and shows the principal part of a metal mold|die. It is explanatory drawing of the crimping process included in the manufacturing process which concerns on this embodiment. It is explanatory drawing of the crimping process which expands and shows the principal part of a metal mold|die. FIG. 10 is an explanatory diagram showing the operation of the cam mechanism when the upper die rises after passing through the bottom dead center; FIG. 5 is an explanatory diagram showing the relationship between the operation of the press machine and the operation of the main parts of the mold;

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

Hereinafter, in describing the embodiments, the upper die attached to the movable side of the mold is lowered by press driving, and the lower punch attached to the fixed side of the mold presses upward. How to explain.

[Processing material]
The processed materials (two steel plates (steel plates) 10 and 11) shown in FIGS. 1A to 1D are called cold-rolled steel plates and high-strength steel plates used for automobile bodies, for example. In this embodiment, two steel plates (metal plates) 10 and 11 are stacked (see FIG. 1A) and set in a mold 2 to be described later to form a hat shape. The two steel plates 10 and 11 formed in a hat shape respectively have convex central portions 10a and 11a and flange portions 10b and 11b formed at both ends of the central portions 10a and 11a. (See FIG. 1B). Further, in this embodiment, the flange portions 10b and 11b of the steel plates 10 and 11 formed into the hat shape are subjected to burring caulking (two left and right positions in this embodiment) in the same mold 2 and in the same process.

Two steel plates 10 and 11 are preliminarily subjected to a drilling process for drilling a hole having a shape as shown in FIG. 1A. The steel plate 10 stacked on the lower side is formed with a deformed hole 10h having alternating convex portions and concave portions. On the other hand, a circular hole 11h is formed in the steel plate 11 placed on the upper side.

After punching, the two steel plates 10 and 11 are superimposed and set in the mold 2, and press working (forming, burring and crimping) is performed with the mold 2 (see FIGS. 1B to 1D). ).

[Outline of mold]
As shown in FIGS. 3A, 3B, and 4, the burring apparatus 1 according to this embodiment includes a mold for performing a molding process for molding and a burring crimping process for burring crimping in one process. 2. FIG. 3A is a diagram showing a state in which the steel plates 10 and 11 are set in the mold 2 before starting working (forming process). FIG. 3B is a diagram showing a state in which the forming process is completed and the process proceeds to the burring crimping process. The mold 2 has a forming die 3a provided on the upper mold 3 for shape formation, and a forming punch 4a provided on the lower mold 4 for shape formation. The molding die 3a is movable in the upper die 3 by sliding in the vertical direction. A crimping punch 5 is fixed to the upper mold die holder 3b, and a burring punch 6 is held in the forming punch 4a of the lower mold 4 so as to be vertically slidable and movable.

The die 2 has a cam mechanism 20 as a synchronous actuation mechanism for causing the burring punch 6 of the lower die 4 to protrude upward in synchronization with the driving of the press machine. The cam mechanism 20 consists of two cams (a first cam 21 and a second cam 22) fixed to the upper die holder 3b and two horizontal cams ( a third cam 23 and a fourth cam 24). In addition, the cam mechanism 20 is provided between the third cam 23 and the fourth cam 24 in order to vertically move the burring punch 6 by the operation of the two horizontal cams (the third cam 23 and the fourth cam 24). It has an arranged burring punch driving cam (fifth cam 25). The third cam 23, the fifth cam 25, and the fourth cam 24 are arranged substantially linearly in the horizontal direction.

[Details of the mold]
On the upper die holder 3b or the lower die holder 4b of the mold 2, the following components are fixed or held in a slidable state.

(Shaping die 3a)
The forming die 3a is arranged on the movable side (upper die holder 3b) of the die 2, and forms the two steel plates 10 and 11 into a hat shape by a recessed portion formed in the central portion. The molding die 3a is movable in the upper die 3 by sliding in the vertical direction. An elastic mechanism (in this embodiment, two gas cushions) 7 arranged above the forming die 3a keeps the forming die 3a in contact with the material to be processed (workpiece) from the middle of press working (after completion of forming) to the bottom dead center. By applying a force in contact, the material to be processed is restrained from slipping during processing.

(Forming punch 4a)
The forming punch 4a is arranged on the fixed side (lower die holder 4b) of the mold 2, and forms the two steel plates 10 and 11 into a hat shape by a convex portion formed in the central portion. A burring punch 6 protruding upward and a third cam 23, a fourth cam 24 and a fifth cam 25 for operating the burring punch 6 are built in the forming punch 4a.

(Cam mechanism 20)
As shown in FIG. 5, the cam mechanism 20 includes a first cam 21, a second cam 22, a third cam 23, a fourth cam 24, and a fifth cam 25. As shown in FIG.

(First cam 21)
The first cam 21 is fixed to the upper die holder 3 b and transmits the motion of the upper die 3 to the third cam 23 of the lower die 4 . The lower end of the first cam 21 is formed with an inclined surface 21a having a predetermined angle (approximately 26 degrees). When the upper mold 3 descends to some extent, the contact between the inclined surface 21a of the first cam 21 and the inclined surface 23a of the third cam 23 is released, and the vertical surface 21b above the inclined surface 21a of the first cam 21 and the third A vertical surface 23b at the tip of the cam 23 abuts thereon.

(Second cam 22)
The second cam 22 is fixed to the upper die holder 3 b and transmits the motion of the upper die 3 to the fourth cam 24 of the lower die 4 . A rotatable piece (cam portion) 22a is provided at the tip (lower end) of the second cam 22. Normally, the tip of the piece 22a is held so as to face the horizontal direction, and the tip surface 22b of the piece 22a is the fourth cam. It abuts on a vertical surface 24a formed on the side surface of the cam 24. As shown in FIG. When the upper die 3 descends to some extent, the contact between the tip surface 22b of the piece 22a and the vertical surface 24a of the fourth cam 24 is released, and the fourth cam 24 can move toward the second cam 22 side.

(Third cam 23)
The third cam 23 is engaged with the fifth cam 25 to move the fifth cam 25 upward (forward movement). The third cam 23 is arranged on the lower mold 4 so as to be movable in the horizontal direction (lateral direction). The inclined surface 23a of the third cam 23, which is the contact surface with the inclined surface 21a of the first cam 21, is formed at a predetermined angle (approximately 26 degrees), and a vertical surface 23b is formed below the inclined surface 23a. . An inclined surface 23c of a predetermined angle (approximately 45 degrees) is formed on the opposite end surface of the third cam 23, and the inclined surface 23c of the third cam 23 is in contact with the inclined surface 25a of the fifth cam 25. .

(Fourth cam 24)
The fourth cam 24 engages with the fifth cam 25 to move the fifth cam 25 downward (retreat). The fourth cam 24 is arranged on the lower die 4 so as to be movable in the horizontal direction (lateral direction). The inclined surface 24b of the fourth cam 24, which is the contact surface with the inclined surface 25b of the fifth cam 25, is formed at a predetermined angle (approximately 45 degrees). 25 is in contact with the inclined surface 25b. A vertical surface 24 a is formed on the opposite end surface of the fourth cam 24 , and the vertical surface 24 a of the fourth cam 24 abuts the tip end surface 22 b of the piece 22 a of the second cam 22 . Even if the second cam 22 operates (lowers) with the operation (lowering) of the upper mold 3, the movement of the fourth cam 24 is restricted by the piece 22a of the second cam 22, so it does not move. When the upper die 3 descends to some extent and the contact between the tip surface 22b of the piece 22a and the vertical surface 24a of the fourth cam 24 is released, the fourth cam 24 moves toward the second cam 22 side.

(Fifth cam 25)
The fifth cam 25 is a cam for vertically moving the burring punch 6 . The fifth cam 25 is arranged on the lower die 4 so as to be movable in the horizontal direction (horizontal direction) and the vertical direction (vertical direction). The inclined surface 25a of the fifth cam 25, which is the contact surface with the inclined surface 23c of the third cam 23, is formed at a predetermined angle (approximately 45 degrees) and is the contact surface with the inclined surface 24b of the fourth cam 24. The inclined surface 25b of the fifth cam 25 is formed at a predetermined angle (approximately 45 degrees). With the movement of the fourth cam 24 restricted by the piece 22a of the second cam 22, when the third cam 23 and the fourth cam 24 sandwich the fifth cam 25 from both directions, the fifth cam 25 moves upward. .

(burring punch 6)
The burring punch 6 is a circular punch for burring the material to be processed (lower steel plate 10) from below. The tip (upper end) of the burring punch 6 is chamfered (see FIG. 2B).

(Caulking punch 5)
The crimping punch 5 is fixed to the upper die holder 3b, and after the burring punch 6 moves downward (retreat) after the burring process, the burring portion 10i (see FIG. 2B) is opened and crushed outward, and the crimping portion 10j (see FIG. 2C). The crimping punch 5 is not fixed to the forming die 3a and can move relative to the forming die 3a.

[Mold operation]
Along with the driving of the press (lowering of the upper die 3), burring caulking is performed by the following operations (i) to (vi). FIG. 9 shows the operations (i) to (vi) (the relationship between the operations of the press and the operations of the main parts of the mold 2) corresponding to the crank angles (0° to 360°) of the press. It is a thing.

(i) The forming die 3a of the upper mold 3 descends to press and restrain the workpieces (two steel plates 10 and 11).

(ii) The forming die 3a of the upper mold 3 is further lowered, and the workpiece (two steel plates 10, 11) is formed into a hat shape between it and the forming punch 4a of the lower mold 4 (see FIG. 3B). ). When the shaping of the workpiece into the hat shape is completed, the workpiece is held between the molding die 3 a of the upper mold 3 and the molding punch 4 a of the lower mold 4 .

(iii) When the upper die 3 is further lowered, the first cam 21 of the upper die 3 is moved downward, and the third cam 23 is moved toward the burring punch 6 (horizontally). At this time, the second cam 22 of the upper die 3 also moves downward, but the fourth cam 24 whose movement is restricted by the piece 22a of the second cam 22 does not move. Therefore, the fifth cam 25 sandwiched between the third cam 23 and the fourth cam 24 from both directions moves upward. As the fifth cam 25 moves upward, the burring punch 6 moves upward (moves forward), and the workpiece (lower steel plate 10) is burred from below (FIGS. 6A and 6B). reference). That is, the downward motion of the upper die 3 is converted into the upward motion of the burring punch 6 by the first cam 21 , the third cam 23 and the fifth cam 25 . After that, the contact between the inclined surface 21a of the first cam 21 and the inclined surface 23a of the third cam 23 is released, and the contact between the vertical surface 21b of the first cam 21 and the vertical surface 23b of the third cam 23 shifts. After that, the third cam 23 does not move in the horizontal direction and stops.

(iv) When the upper mold 3 is further lowered, the second cam 22 is moved downward, and the contact between the tip end surface 22b of the piece 22a of the second cam 22 and the vertical surface 24a of the fourth cam 24 is released. 4 cam 24 can move to the second cam 22 side. Since the fourth cam 24 moves toward the second cam 22 after this, the fifth cam 25 moves downward, and the burring punch 6 moves downward (retreat).

(v) When the upper die 3 is further lowered, the crimping punch 5 comes into contact with the burring portion 10i of the workpiece (lower steel plate 11). The tip portion of the burring portion 10i is bent radially outward from the center of the hole by the crimping punch 5, and is crushed by the horizontal surface of the ring-shaped (stepped portion) of the burring punch 6 to be crimped (FIGS. 7A and 7B). 7B).

(vi) After passing the bottom dead center, the upper die 3 rises. At this time, the piece 22a at the lower end of the second cam 22 and the fourth cam 24 abut against each other, but the piece 22a is rotated by the rotation mechanism 22c to avoid being caught by the fourth cam 24 and interfering with it (Fig. 8).

As described above, the mold 2 using the cam mechanism 20 has been described in the present embodiment. For example, if a hydraulic cylinder is arranged below the burring punch 6 and is synchronized with the operation of the press machine, and a synchronous operation mechanism for moving the burring punch 6 up and down is provided, implementation is possible.

[Effects, etc.]
The effects of this embodiment will be described below.

(1) The method of manufacturing a pressed product according to the present embodiment involves forming two steel plates 10 and 11 on top of each other and joining the steel plates 10 and 11 by burring and caulking. The manufacturing method includes a forming step in which two steel plates 10 and 11 are sandwiched between a forming die 3a of an upper mold 3 and a forming punch 4a of a lower mold 4 and formed into a desired shape. In addition, after the forming process, the burring punch 6 arranged in the lower mold 4 is directed toward the steel plates 10 and 11 by driving the synchronous operation mechanism (cam mechanism 20) synchronized with the operation of the upper mold 3. A burring step is included in which the steel plates 10 and 11 are moved forward to form burring portions 10i on the steel plates 10 and 11 by the burring punch 6. FIG. Further, the manufacturing method includes a burring punch retreating step of retreating the burring punch 6 from the steel plates 10 and 11 by driving the cam mechanism 20 after the burring step. Further, in the manufacturing method, after the burring punch retracting step, the crimping punch 5 arranged in the upper mold 3 is moved forward toward the steel plates 10 and 11, and the tip of the burring portion 10i is bent outward by the crimping punch 5. It includes a crimping step of forming the crimped portion 10j.

(2) In the above-described method of manufacturing a pressed product, the cam mechanism 20 includes a forward movement mechanism (first cam 21 and third cam 23) for moving the burring punch 6 forward toward the steel plates 10 and 11; and a retracting mechanism (second cam 22 and fourth cam 24) for retracting the burring punch 6 from the steel plates 10, 11.

(3) The burring device 1 superimposes two steel plates 10 and 11 and performs forming and burring caulking. A burring apparatus 1 includes a mold 2 having an upper mold 3 and a lower mold 4, a forming die 3a and a crimping punch 5 arranged in the upper mold 3, and a forming punch 4a and a burring punch 6 arranged in the lower mold 4. , and a cam mechanism 20 driven in synchronization with the operation of the upper die 3 . The cam mechanism 20 advances the burring punch 6 toward the steel plates 10 and 11 in synchronism with the operation of the upper die 3 to form a burring portion 10i on the steel plates 10 and 11 with the burring punch 6. After the punch 6 is moved backward from the steel plates 10, 11, the crimping punch 5 is moved forward toward the steel plates 10, 11, and the tip of the burring portion 10i is bent outward by the crimping punch 5 to form the crimped portion 10j. configured to

(4) In the burring machine 1 described above, the cam mechanism 20 includes forward movement cams (first cam 21 and third cam 23) for moving the burring punch 6 forward toward the steel plates 10 and 11, and a burring mechanism. and retraction cams (second cam 22 and fourth cam 24) for retracting the punches 6 from the steel plates 10 and 11.

A forming die 3a is arranged in the upper mold 3 of the mold 2 so as to be movable in the pressing direction, and a forming punch 4a is arranged in the lower mold 4. As shown in FIG. Also, the burring punch 6 is placed on the fixed die (lower die 4), and the crimping punch 5 is placed on the movable die (upper die 3). A cam mechanism 20 driven in synchronism with the movement of the upper die 3 first drives the burring punch 6 to perform burring from below, and then after the burring punch 6 retreats, the crimping punch 5 is driven to perform crimping from above. to do. Therefore, it is possible to perform molding first, then burring, and finally crimping in the same processing process using one mold 2, thereby reducing the number of processes and improving productivity. Cost reduction becomes possible.

When the lower die is provided with a cushion mechanism as in the prior art, it is difficult to provide the lower die with a cam mechanism because the lower die accompanies vertical movement. Therefore, when the lower die is provided with a cushion mechanism, it has not been possible to perform the molding process into the desired shape and the burring and caulking process in the same process (single die).

On the other hand, in the present embodiment, since the lower die 4 is a fixed die (the forming punch 4a is fixed), the cam mechanism 20 that operates following the operation of the upper die 3 is incorporated in the lower die 4. , and the burring punch 6 can be moved forward and backward.

In some prior art, the two parts are individually stamped and the two parts are joined by spot welding.

On the other hand, in this embodiment, press working and joining can be performed in one process, and it is possible to reduce processing costs by reducing the number of processes and improving productivity, and it is also possible to improve joining quality. become.

By the way, the method of manufacturing a pressed product and the burring device of the present invention have been described with the above-described embodiment as an example, but they are not limited to this embodiment, and other embodiments can be applied without departing from the gist of the present invention. Various types can be adopted.

As described above, the upper die attached to the movable side of the mold is lowered by the press drive, and the lower punch attached to the fixed side of the mold presses upward in an embodiment. explained. However, the upper mold (forming die) and the lower mold (forming punch) may be reversed. That is, a press molding method may be used in which an upper punch and a lower die are used to perform press molding in the downward direction.

1 burring device 2 mold 3 upper mold (movable mold)
3a forming die 4 lower mold (fixed mold)
4a forming punch 5 caulking punch 6 burring punch 10 steel plate (metal plate)
10i Burring portion 10j Crimping portion 11 Steel plate (metal plate)
20 cam mechanism (synchronous actuation mechanism)
21 First cam (advance movement cam, forward movement mechanism)
22 Second cam (backward movement cam, backward movement mechanism)
23 Third cam (forward movement cam, forward movement mechanism)
24 4th cam (backward movement cam, backward movement mechanism)
25 5th cam

Claims (4)

A method for manufacturing a pressed product, wherein two metal plates are superimposed and molded, and the metal plates are joined by burring and caulking,
a molding step of sandwiching the two superimposed metal plates between a movable mold and a fixed mold to form a desired shape;
After the forming step, the burring punch arranged on the fixed mold is moved forward toward the metal plate by driving the synchronous operation mechanism synchronized with the operation of the movable mold, and the burring punch moves the metal plate. a burring step of forming a burring portion;
a burring punch retracting step of retracting the burring punch from the metal plate by driving the synchronous operation mechanism after the burring step;
a crimping step of forwardly moving a crimping punch disposed on the movable mold toward the metal plate after the burring punch retracting step, and bending the tip of the burring portion outward by the crimping punch to form a crimped portion; ,including,
Method of manufacturing pressed products. The synchronous actuation mechanism is
a forward movement mechanism for moving the burring punch forward toward the metal plate;
a retraction mechanism for retracting the burring punch from the metal plate;
A method for manufacturing a pressed product according to claim 1. A burring device that superimposes two metal plates and performs molding and burring and crimping,
a mold having a movable mold and a fixed mold;
a crimping punch arranged on the movable mold;
a burring punch arranged in the fixed mold;
a cam mechanism driven in synchronization with the operation of the movable mold,
The cam mechanism advances the burring punch toward the metal plate in synchronism with the operation of the movable mold, forms a burring portion on the metal plate with the burring punch, and further moves the burring punch. After moving backward from the metal plate, the crimping punch is moved forward toward the metal plate, and the tip of the burring portion is bent outward by the crimping punch to form a crimped portion.
Burring processing equipment. The cam mechanism is
a forward movement cam for forwardly moving the burring punch toward the metal plate;
a retraction cam for retracting the burring punch from the metal plate;
The burring device according to claim 3.

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