JPS6320411Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a press die for bending.

To perform bending using a press, a pair of dies each having a convex surface and a concave surface having a predetermined curvature are usually used to clamp the workpiece. 1st
The figure and FIG. 2 show the conventional processing method. In the system shown in FIG. 1, a workpiece 2 is placed on a die 1 having a concave surface, and the workpiece 2 is pressed down by a punch 3 having a convex surface attached to a ram 4.
This is to bend a workpiece 2 which is clamped between both curved surfaces. In this method, there is nothing to restrain the workpiece 2 during pressurization, so not only is the processing accuracy low, but
Since the end of the workpiece 2 jumps up, there is a drawback that it is supported by the ram 4. In the method shown in FIG. 2, a curved surface is provided at the end of the die 5, and a punch 6 having a concave surface is lowered relative to the curved surface. 2 on the die 5, there is no disadvantage mentioned above. However, on the other hand, the force that presses the work 2 against the die 5 requires a component in the direction perpendicular to the descending direction of the ram 4. As a result, the springback rate of the workpiece 2 increases, making it impossible to bend the workpiece 2 according to the curvature of the die 5. In addition, with either method, mold scratches and crushing scratches occur on the workpiece surface.
There is a risk of center creases occurring at the bending part of the workpiece.

The present inventor filed an application (Utility Application No. 126481 of 1981) (hereinafter referred to as the "prior application") for a device called "Press mold for bending" with the aim of eliminating the above-mentioned drawbacks, but the present invention Since this invention relates to an improvement of the invention of the earlier application, it will be explained first.

FIG. 3 shows an embodiment of the invention of the prior application. Reference numeral 11 denotes a lower mold attached to the bolster 12, and a die 13 having a convex surface extending from the upper surface to the right side is fixed thereto. A flat plate-like mounting table 14 is arranged next to the upper surface of the die 13, and is also fixed to the lower mold 11. The upper die device 16 attached to the ram 15 includes a presser plate 17 and an arm 18. The holding plate 17 is attached to the shaft 1
9 is passed through the upper mold base 20 to be supported so as to be vertically movable, and is urged downward by a spring 21. The arm 18 has its upper end pivotally supported on the upper die base 20 by a pivot 22, and is provided with a roller 23 at its lower end. 2
4 is the extension part 20a of the upper die base 20 and the arm 18
It is a compression spring provided between the lower end of the arm 18 and biases the arm 18 to rotate clockwise.
Reference numeral 25 denotes a guide rod passing through the compression spring 24, one end of which is rotatably attached to the arm 18, and the other end rotatably and slidably supported by the extension 20a.

With the ram 15 raised, a grid-shaped workpiece 10 shown in FIG. 4 is placed on the mounting table 14.
The set position of the work 10 is accurately determined by a position regulating piece 26 provided on the mounting table 14. Further, the horizontal bar 10a of the workpiece 10 fits into a groove 14a provided in the mounting table 14. In this raised state of the ram 15, the arm 18 is rotating clockwise from the illustrated position, and the range of rotation is limited to the guide rod 2.
The nut 27 screwed onto the end of the extension part 20a
roller 23
is located above the starting end of the curved surface of the die 13.

When the ram 15 descends, the holding plate 17 first presses the workpiece 10 onto the mounting table 14. Subsequently, the roller 23 at the tip of the arm 18 comes into contact with the workpiece 10, as shown by the chain line, and presses it down. Since the axis of the roller 23 is located slightly to the right of below the pivot portion 22 of the arm 18, the reaction force acting on the roller 23 generates a component force that rotates the arm 18 in a counterclockwise direction. As a result, roller 23 is ram 1
As the workpiece 5 is lowered, the workpiece 10 is rotated and lowered while being pressurized toward the die 13, and reaches the position shown by the solid line in the figure. This pressing force is mainly applied to the ram 15 when the roller 23 is near the top surface of the die 13.
In the illustrated position, it is provided by the downward force of the spring 24, and is always kept within a proper range of values. The workpiece 10 is equipped with a horizontal bar 10b, but the groove 13a of the die 13
Since it fits into the holder, there will be no problem.

When the ram 15 is raised, the roller 23 rises while rolling on the workpiece 10, the arm 18 and the presser plate 17 are lifted and returned to their original states, and the bent workpiece 10 is taken out as shown in FIG. be able to.

Note that for workpieces that require a large bending force, such as pipes and plate materials, an air cylinder can be used instead of the spring 24.

As described above, in the prior invention, a roller is provided at the tip of an arm that is pivotally supported on the upper mold, and the roller is rolled along the curved surface of the die, and the workpiece is pressurized toward the die by the roller. The pressure applied to the workpiece can always be kept within an appropriate range.

Therefore, it is possible to reduce the springback rate without causing crushing scratches or bends in the workpiece. In addition, since the rollers roll against the workpiece, there are no mold scratches on the workpiece surface, and it is possible to bend painted or plated workpieces. Furthermore, as is clear from the above embodiments, even workpieces having inwardly protruding parts, such as the horizontal bar 10b, can be processed simply by providing relief grooves in the die.

The above is the content of the invention of the prior application, but when the depth of the workpiece is long, the axial length of the roller becomes long, and there is a risk that it will not rotate smoothly.

It is an object of the present invention to solve the above-mentioned problems and also to make it possible to deal with workpieces whose shapes differ somewhat in the depth direction.

FIG. 6 shows the arm 28 used in the present invention. This arm 28 is connected to the pivot portion 22
Accordingly, the arm 18 of the prior application is pivotally supported on the upper die base 20 instead of the arm 18 of the prior application. Arm 2
8 is formed into a plate shape as a result of having a long depth l to match the long workpiece 10, and a plurality of rollers 29a to 8 are formed along the longitudinal edge of the plate.
29f is rotatably supported by shafts 30a to 30f. The arm 28 has a slit 31a~
31e, it is divided into arm pieces 32a to 32f for each roller 29a to 29f. The base of each arm piece 32a to 32f is formed into a thin wall by a groove 33, and is connected to a boss portion 34. As a result, each of the arm pieces 32a to 32f is integrated to constitute the arm 28, but can rotate independently to some extent due to the flexure of the thin portion.

The arm 28 is pivoted to the upper mold base 20 instead of the arm 18 of the prior application shown in FIG.
4. As the ram 15 descends, the rollers 29a to 29f independently move the workpiece 10.
can be pressurized and independently displaced within a certain range,
The pressing force is distributed to each roller 29a to 29f,
It will act uniformly. Also, each roller 29
Since the axes 30a to 30f are independent from each other, a to 29f can rotate smoothly.

As mentioned above, each roller 29a to 29f is
Since the workpiece 10 is pressurized independently, each portion of the rollers 29a to 29f can be uniformly processed even if the wire rods that constitute the wire rods have different thicknesses.
It is also possible to process them into different curvatures.

Note that each arm piece 32a to 32f is
Instead of being integrally formed as 8, they may be completely separated. Further, instead of urging each arm piece 32a to 32f with a separate spring, a common spring may be used to urge each arm piece 32a to 32f. In that case, an elastic body is interposed in the pressurizing portion of each arm piece 32a to 32f, so that each arm piece 32a to 32f can be independently displaced.

As described above, the present invention divides the roller that applies pressure to the workpiece into multiple parts in the axial direction,
Since the divided rollers are made to operate independently of each other, the following effects can be obtained in addition to the effects of the invention of the prior application. That is, even for a workpiece with a long depth dimension, the axial dimension of the roller can be divided and shortened, and defective rotation of the roller due to deflection of the axis does not occur. Therefore, no mold scratches are left on the surface of the workpiece, and the paint or plating is not damaged. In addition, since each roller operates independently, uneven distribution of pressing force due to uneven roller contact is eliminated, and even workpieces with partially different thicknesses can be processed uniformly. In extreme cases, workpieces can be partially processed. It is also possible to bend it to different curvatures.

[Brief explanation of the drawing]

Figures 1 and 2 are front views showing a conventional example, Figure 3 is a front view showing an embodiment of the prior invention, Figure 4 is a perspective view of the workpiece before processing, and Figure 5 is a front view of the workpiece before processing. A perspective view of the subsequent workpiece, FIG. 6A, shows an example of the arm used in the present invention, a front view seen from the direction of the arrow in FIG. 3, and FIG. 6B a side view of the main parts. 11... Lower die, 13... Die, 16... Upper die device, 17... Holder plate, 20... Upper die base, 24
...Spring, 28...Arm, 29a-29
f...Roller, 30a-30f...Shaft, 32a
~32f...Arm piece.

Claims (1)

[Scope of utility model registration request] The die is attached to the lower mold and has a curved surface extending from the upper surface to the side surface, an arm is pivotally supported on the upper mold base and has a roller at its tip, and a presser plate is provided on the upper mold base. A bending press comprising an urging member that constantly presses and rotates toward the die surface, so that the roller rolls along the curved surface of the die and applies a pressing force thereto. 1. A press mold for bending, characterized in that the roller is divided into a plurality of parts in the axial direction thereof, and each of the divided rollers applies pressing force independently to each other.