JPH0553722U - Composite press die for bending and bending - Google Patents

Abstract

(57) [Abstract] [Purpose] To correct the springback so that the press-molding process that was conventionally performed in a separate process can be completed in one process. [Structure] The upper die 10 is provided with a punch 12 for bending the work W in the vertical direction and drive cams 11, 11, while the lower die 20 is provided with the drive cams 11,
The punch 12 includes slide cams 21 and 21 for moving the work W in a horizontal direction as the work 11 descends and bending the work W, and a pad 22 for supporting the work W from below.
Is stronger than the pressing force required to bend the work W, and the upper mold 1
Cylinders 13 to 13 having a rod protruding force that is weaker than the mold clamping force of 0 are slidably supported in the up and down direction while being pressed downward.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a compound press die for bending and bending which is used when a strip-shaped work is press-formed to obtain a frame material having a substantially U-shaped cross section, for example.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, for example, there is a frame material forming a body of an automobile which is press-molded into a substantially U-shaped cross section. When manufacturing this frame material, first, as shown in FIG. A work W (indicated by a chain double-dashed line in the figure) is set on the lower die 32, and then the upper die 31 is lowered to form a punch 33 attached to the upper die 31 on the lower die 32. By pushing between the blades 34, 34, both side edges of the work W are bent at substantially right angles (parallel to each other).

However, as shown in FIG. 7, when the work W ′ after the bending is taken out from the press die 30, both sides of the work W ′ are opened to the outside by spring back, and the both sides are left as they are. It is not possible to obtain a substantially U-shaped cross section that is substantially parallel.

Therefore, as shown in FIG. 6, the bent work W'is set in a separately prepared cam die 40 to be bent to correct the springback. That is, the side edges of the work W ′ are bent further inward by an acute angle by performing this off-bending process, whereby the side edges are opened outward again by the spring back, so that the section having a substantially U-shaped cross section is formed. The final product F could be obtained.

As described above, it is necessary to presume the springback in advance and perform the side-bending in which both side edges are bent further inward at an angle corresponding to the springback. Bending) and final bending (lateral bending) are required, and it is necessary to prepare separate press dies 30 and 40 for each step.

The cam die 40 lowers the drive cams 41, 41 attached to the upper die to slidably contact slide cams 43, 43 attached to the lower die 42 so as to be slidable in the left-right direction in the drawing. By doing so, the slide cams 43, 43 are moved toward the temporarily bent work W'to perform the bending.

[0007]

[Problems to be solved by the device]

 As described above, conventionally, when press-molding a frame material having a substantially U-shaped cross section, two steps of temporary bending and finish bending are required, and separate press dies 30, 40 are prepared for each step. Therefore, there is a problem that the manufacturing cost of this pressed product (frame material) is high. In particular, the press die used to form this frame material is usually manufactured by using a large amount of expensive die material in order to improve the galling resistance, so the investment cost as the die cost is high. , Was a factor that further increased the manufacturing cost.

Further, since it is necessary to remove from the press die 30 for temporary bending and set it on the cam die 40 for side bending, it takes time and labor, and therefore its working efficiency is not good. ..

Further, since a separate press machine is installed in each process, there is a problem that a large installation space is required.

The present invention has been made in view of these conventional problems, and it is possible to perform temporary bending and off-bending as finish bending in one process, and to reduce the manufacturing cost of press-formed products. It is an object of the present invention to provide a compound press die for bending and bending which can be bent.

[0011]

[Means for Solving the Problems] In order to solve the above-mentioned problems of the present invention, the upper die includes a punch for bending a workpiece in a vertical direction and a drive cam, while the lower die Is equipped with a slide cam for moving the work horizontally to bend the work as the drive cam descends, and a pad for supporting the work from below.The punch is a pressing force required for bending the work. It is characterized in that it is supported slidably in the vertical direction in a state of being pressed downward by a cylinder having a stronger rod protruding force that is weaker than the upper mold clamping force.

[0012]

[Action]

 According to the above configuration, the upper die is lowered once from the top dead center to the bottom dead center, whereby the bending (temporary bending) and the side bending (finish bending) are completed.

That is, as the upper die descends, the punch descends and is pushed between the slide cams to first temporarily bend the work. At this time, the punch is pressed down by the cylinder while being pressed down by the cylinder without moving relative to the upper die.

Next, when the provisional bending is completed, the downward movement of the punch is stopped, and the upper die further descends against the pushing force of the rod of the cylinder. At this time, the punch is stopped, so that the punch and the upper die move relative to each other.

When the upper die is further lowered, the drive cam is slidably contacted with the slide cam, and the slide cam horizontally moves toward both side edges of the temporarily bent work, and the both side edges are moved to the punch. The work is bent by pressing to.

[0016]

【Example】

 Next, an embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, the composite press die 1 of this example includes an upper die 10 that is supported so as to be movable up and down and a fixed lower die 20, and the upper die 10 has drive cams 11, 11. (The drive cam 11 on the right side is not shown) and a punch 12 are provided, and the lower die 20 is provided with left and right slide cams 21 and 21 and a pad 22 for supporting the work W from below. ..

The drive cam 11 is for horizontally moving the sliding cam 21 provided on the upper surface of the lower die 20 as the upper die moves downward. It is fixedly installed. A cam surface 11a that is inclined at a constant angle is formed at the lower right corner of the illustrated left drive cam 11. By slidingly contacting the cam surface 11a with the cam surface 21a of the slide cam 21 on the left side in the figure, the slide cam 21 horizontally moves to the right side in the figure.

The right-side drive cam (not shown) has a cam surface symmetrically formed with respect to the left-side drive cam 11, and the lower cam of the upper die 10 moves this cam surface to the right-side slide cam. By slidingly contacting the cam surface of 21, the slide cam moves horizontally to the left in the drawing.

The left side surface 11b of the drive cam 11 on the left side of the drawing is adapted to be brought into sliding contact with the side wall 20a formed on the upper surface of the lower die 20 by the lower movement of the upper die 10, whereby the drive cam 11 is driven. However, the slide cam 21 can be efficiently moved without escaping to the left in the drawing. Similarly, a drive cam (not shown) is also slidably in contact with the right side wall of the lower mold 20.

Next, the punch 12 moves downward together with the upper die 10 to move the strip-shaped work W (shown by a chain double-dashed line in the figure) between the slide cams 21 and 21 as bending blades. It is for pushing the work W to temporarily bend it, and is provided with a strip plate-shaped sliding support portion 12a and a main body portion 12b having a trapezoidal cross section.

Here, in the center of the lower surface of the upper die 10, an outer groove portion 10 a and an inner groove portion 10 b are formed in a stepped shape along a direction orthogonal to the paper surface in FIG. 1, and the sliding portion of the punch 12 is formed. 12a is fitted along the outer groove portion 10a, whereby the punch 12 is slidably supported in the upward and downward directions.

A plurality of cylinders 13 to 13 are attached to the bottom surface of the inner groove portion 10b at appropriate intervals along the inner groove portion 10b with the rod 13a thereof directed downward.

The cylinder 13 is a “tanker cylinder” (a product name of a cylinder manufactured by Teledyne-Hyson Co., Ltd.) in which nitrogen gas is hermetically sealed, and has a higher rod protruding force than a normal air cylinder. (Pressure of nitrogen gas), the rod 13a is always urged in the protruding direction, and an external force (the mold clamping force of the upper mold 10 in this example) equal to or higher than the rod protruding force is applied. It is designed to pull in by being added. That is, the rod protruding force of the cylinder 13 is set higher than the pressing force required to bend the work W and smaller than the mold clamping force of the upper mold 10, whereby the cylinders 13 to 13 are compressed. It functions as a spring.

Upward movement of the punch 12 with respect to the upper die 10 is restricted by the cylinders 13 to 13, and only when the die clamping force of the upper die 10 is applied, the punch 12 resists the rod protrusion force of the cylinder to the outer groove portion. It is adapted to move upward along 10a.

On the other hand, the left and right side surfaces of the main body portion 12b of the punch 12 in the figure are inclined side surfaces 12e, 12e which incline downward and expand at a constant inclination angle. The angle of inclination of both inclined side surfaces 12e, 12e is an angle corresponding to the springback amount at the time when both side edges of the work W are bent along the inclined side surfaces.

Reference numeral 14 in the drawing is a retainer pin for preventing the punch 12 from falling, and a projecting head portion 14 a is formed at the lower end portion in the drawing and a screw portion is formed at the upper end portion, and the retainer pin 14 is formed in the longitudinal direction of the punch 12 ( An appropriate number are arranged at appropriate intervals along the direction (perpendicular to the paper surface). That is, each retainer pin 14 is inserted into the stepped holes 12c to 12c formed in the punch 12 in the vertical direction in the drawing from below in the drawing, and is screwed and fixed to the bottom of the inner groove 10b of the upper mold 10. There is. The retainer pins 14 to 14 are alternately arranged so as not to interfere with the cylinders 13 to 13.

Next, the slide cams 21 and 21 provided on the upper surface of the lower die 20 are provided as bending blades for further bending the workpiece W temporarily bent by the punch 12 respectively. A cam surface 21a is formed corresponding to the cam surface 11a of the drive cam 11. Although not shown, both slide cams 21 and 21 are spring-biased in a direction in which they separate from the work W (directions in which they move away from each other).

In the slide cams 21 and 21 configured as described above, when the drive cam 11 descends along with the upper die 10 and its cam surface 11 a is brought into sliding contact with the cam surface 21 a of the slide cam 21, respectively. It advances toward the work W against the spring biasing force, and thereby, the bending is performed. Further, when the drive cam 11 rises, both the slide cams 21 and 21 retreat in the direction away from the work W by the spring biasing force.

The pad 22 is provided to receive the work W pressed by the punch 12 from below and support the work W. The pad 22 is provided between the slide cams 21 and 21 and is provided on the upper surface of the lower mold 20. It is slidably fitted in and supported by the formed groove portion 20a, and is biased upward by the compression coil spring 23.

The composite press die 1 of this example is configured as described above. Next, the press forming process by the composite press die 1 will be described with reference to FIGS. 2 to 4.

First, as shown in FIG. 2, the work W is set in the mold open state. At this time, both slide cams 21 and 21 are in their retracted positions (positions spaced apart from each other), and the pad 22 rises between both slide cams 21 and 21 so that the upper surface of both slide cams 21 and 21 is both slide cams 21 and 21. Is substantially aligned with the upper surface of the workpiece W, and the work W is placed and set on the upper surfaces of the slide cams 21 and 21 and the pad 22. The punch 12 is regulated by the retainer pin 14 and is located at the lower limit of its stroke.

After the work W is set in this manner, the upper die 10 is lowered and the work W is temporarily bent as shown in FIG.

At this time, while the upper die 10 is descending, the punch 12 comes into contact with the work W and rises from the above stroke lower limit (elevates with respect to the upper die 10) so that its upper surface comes into contact with the rod 13a of the cylinder 13. .. Since the rod protruding force of the cylinder 13 is larger than the force required to bend the work W, when the upper die 10 is further lowered, the punch 12 is lowered together with the upper die 10 to move the pad 22. While pushing down, the work W is pushed between the slide cams 21 and 21 as bending blades as illustrated.

While the work W is being pushed between the slide cams 21 and 21, the temporary bending of the work W is completed when the pad 22 descends and reaches the lower limit of its stroke. At the time of completion of the temporary bending, both side edges of the temporarily bent work W are bent substantially at right angles and are parallel to each other (in a state of substantially U-shaped cross section). Moreover, at this time, the work W is pressed and fixed to the punch 12, and the spring back is restricted by the slide cams 21 and 21 on both side edges thereof.

After the temporary bending of the work W is completed in this way, the upper die 10 is further lowered, and as shown in FIG. 4, the bending as the finish bending is continuously performed with the temporary bending.

That is, the work W is pressed and fixed to the punch 12 in a state where the work W is temporarily bent into a substantially U-shaped cross section, and the cam surface 11 a of the drive cam 11 slides by further lowering the upper die 10 from this state. The cam surface 21a of the cam 21 is slidably contacted, whereby both slide cams 21 and 21 move forward (move in a direction in which they approach each other).

When both slide cams 21 and 21 advance, both side edges of the work W are pressed against both inclined side surfaces 12e and 12e formed on the main body portion 12b of the punch 12 and further bent inward at a constant angle. ..

When both side edges of the work W are sufficiently pressed against the inclined side surfaces 12e, 12e, the upper die 10 reaches the bottom dead center and its descending is stopped, whereby the bending is completed.

Next, the mold opening is performed. That is, the upper die 10 starts to move up, the slide cams 21 and 21 move backward (move in a direction away from each other) accordingly, and the punch 11 also starts to move up. As the punch 11 rises, the pad 22 rises between the slide cams 21 and 21. As a result, the work W that has been subjected to the finish bending, that is, the frame material having a substantially U-shaped cross section as the final pressed product F is taken out. This completes a series of composite pressing steps.

Here, when both slide cams 21 and 21 retreat, both side edges of the work W after completion of the finish bending are opened by spring back, and this spring back is presumed in advance and corrected by lateral bending. Due to this spring back, both side edges are bent substantially at right angles and are parallel to each other, that is, they are precisely formed into a substantially U-shaped cross section required for a product.

As described above, according to the composite press die 1 of this example, the temporary bending of the work W and the bending as the finish bending are continuously performed as the upper die 10 is lowered once. .. That is, it becomes possible to perform the two steps of temporary bending and bending, which were separately performed to correct the springback, with a single press die and one shot.

As a result, the die cost can be saved, and the cost of the pressed product can be reduced.

Further, since the man-hours are reduced, the processing time is shortened, the labor of the operator can be saved, and the work efficiency can be improved.

Further, since it is not necessary to install a separate press machine in each process as in the conventional case, it is possible to effectively use the installation space.

[0046]

[Effect of the device]

 According to the present invention, the two steps required to correct the springback after pressing can be performed with a single press die and one shot, so the cost of the press product can be reduced through the saving of die cost. In addition, since the labor of the operator can be saved, the efficiency of the press work can be promoted.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a press die when the die is closed according to an embodiment of the present invention.

FIG. 2 is likewise a vertical cross-sectional view of the press die when the die is opened.

FIG. 3 is likewise a vertical cross-sectional view of the press die after completion of temporary bending.

FIG. 4 is likewise a vertical cross-sectional view of the press die when finishing bending is completed.

FIG. 5 is a vertical cross-sectional view of a conventional press die for temporary bending when the die is closed.

FIG. 6 is a longitudinal sectional view of a conventional press die for finish bending when the die is closed.

FIG. 7 is an explanatory diagram of springback in each conventional process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Composite press type 10 ... Upper type 11 ... Drive cam 12 ... Punch 12e ... Inclined side surface 13 ... Cylinder 13a ... Rod 14 ... Retainer pin 20 ... Lower type 21 ... Slide cam 22 ... Pad 23 ... Compression coil spring

Claims (1)

[Scope of utility model registration request] 1. An upper die is provided with a punch for vertically bending a work, and a drive cam, while a lower die is moved horizontally as the drive cam descends. And a pad for supporting the work from below, the punch is
A bend characterized by being supported slidably in the vertical direction while being pressed downward by a cylinder having a rod protruding force that is stronger than the pressing force required to bend the work and weaker than the upper mold clamping force. And a complex press die for side bending.