JPS6343732A - Punching die - Google Patents

Abstract

PURPOSE:To prevent the deformation of a punching material by fixing the plate covering a gap to the face at the punching side of a stripper in the punching die equipped with the stripper consisting of a rubber-shaped elastic plate stock. CONSTITUTION:The stripper 5 of the upper die is composed of the elastic body plate of an urethane rubber, etc., and stuck on the lower face of a holder 1 by an adhesive. The plate 11 consisting of the steel plate in the same thickness as that of a work W is stuck on the lower face of the stripper 5 so as to cover the gap of a die 3 and stripper 5. On the other hand the stripper 6 of the lower die consisting of an urethane rubber, etc., is stuck on the upper face of a holder 2 and a steel made plate 12 is arranged as well on the upper face of the stripper 6 convering the gap of a punch 4 and stripper 6. When the work W is punched with this punching die, the deformation at the peripheral edge of a punching material can be prevented because of the friction resistance in the cutter and work W being reduced with the clearance between cutters being made optimum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a press cutting die, and particularly to a cutting die equipped with a stripper made of an elastic material such as synthetic rubber.

(Prior art) If an elastic body with rubber-like elasticity such as synthetic rubber is used instead of steel for the stripper in a press cutting die, the structure of the cutting die is simplified and the tightening member supporting the stripper plate is prevented from loosening. This has the advantage of eliminating problems with springs, noise, etc.

A conventional example of a cutting die equipped with such a stripper is disclosed in Japanese Utility Model Application No. 61-67924. This is a cutting die consisting of a pair of upper and lower dies as shown in FIG.
A die 3 and a punch 4 are fixed to the upper die holder 1 and the lower die holder 2, respectively, with bolts. A stripper 5 made of a rubber material is attached to the die holder 1 so as to fill the void inside the die 3. On the other hand, a stripper 6 made of a rubber material is attached to the lower mold holder 2 so as to surround the outer peripheral side of the punch 4 of the lower mold. A gap C is provided between these cutters and the stripper to release distortion of the stripper during punching.

(Problems to be Solved by the Invention) When the strippers 5 and 6 are used, there is a problem that the workpiece or punched product is deformed due to the gap C. This will be explained with reference to FIGS. 4 and 5. FIG. 4 shows a state in which the upper mold reaches the bottom dead center of the press stroke and punches out the workpiece W.

In this state, the strippers 5 and 6 are compressed, and the central part of the stripper in the thickness direction freely extends in the horizontal direction of the paper.
The surface layer in contact with the workpiece is restrained from elongation by frictional force. Therefore, annular cavities 8 and 9 having a substantially triangular cross section are formed surrounded by the stripper, the die (or punch), and the workpiece.

However, in this state, no abnormal deformation occurs in the punched material 7.

FIG. 5 shows the state in which the upper die is lifted up by the press. Due to the elasticity of the stripper, when the workpiece W and the punched material 7 are pushed out, the workpiece and the punched material are subjected to frictional force between them and the cutter. Deformation of the workpiece or punched material due to this frictional force cannot occur with the conventional spring-type stripper plate, which can be installed with a minute gap, but because of the above-mentioned voids 8 and 9, the peripheral edge 10 of the cutting part is deformed. there were. In an attempt to solve this problem, an attempt was made to apply an anti-friction agent such as molybdenum disulfide to the surface of the strippers 5 and 6 to alleviate the elongation restraining force on the surface layer, but the expected effect could not be obtained. There wasn't.

The present invention has been made in view of the above points.
The purpose is to provide a press cutting die that is equipped with a stripper made of an elastic body having rubber-like elasticity and that can eliminate deformation of the punched material even if a gap is formed for strain relief. .

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a holder 1 as shown in FIGS.
, 2 is attached with a pair of punching blades consisting of a die 3 and a punch 4, and a stripper made of a plate material having rubber-like elasticity is fixed to a position opposite to the die 3 and punch 4 of each holder, and this stripper and the above-mentioned blade This is an improvement to a press cutting die constructed by providing a gap between the two parts to allow distortion of the stripper during punching.

In the present invention, a flat plate covering the gap is fixed to the punching side surface of the stripper.

(Function) In a product configured in this way, after punching is completed,
] As the second die rises, the stripper that fixes the flat plate pushes out the punched material by the restoring action. At this time, the void described in the conventional technique is still formed, but the periphery of the cutting part is different from the conventional cutting die in that the moment of frictional force that tries to deform the punched material Since the rigidity of the flat plate is increased in addition to the rigidity of the punched material, deformation of the punched material can be prevented. Further, since the flat plate alleviates heat transfer due to punching, it is possible to prevent adverse effects caused by the heat of the stripper. Furthermore, since the impact force during punching is transmitted to the stripper through the flat plate, the stripper is not damaged, and the life of the stripper can be significantly extended.

(Example) The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 shows a press cutting die showing one embodiment of the present invention. In this figure, holders 1 and 2, a die 3, and a punch 4 have the same functions as the parts shown in FIG. 3, and therefore are given the same reference numerals and their explanations will be omitted.

The upper mold stripper 5 is made of urethane rubber with a rubber shore hardness of 90°, and has a thickness of about 15 mm. This was attached to the lower surface of the holder 1 with an adhesive, and the gap C1 between it and the die 3 was set to 2 m. Further, a flat plate 11 made of a static plate having the same plate thickness as the work W of 1.6 m was attached to the lower surface of the flat collar of the strip 4.

This flat plate 11 had the same shape as the punched plate material, the gap C3 between it and the die 3 was 0.05 mm, and the thickness of the stripper 5 was adjusted so that its lower surface was substantially flat with the lower surface of the die 3.

On the other hand, the upper mold stripper 6 was also attached to the upper surface of the holder 2 using the same urethane rubber as described above, with a gap C2 between it and the punch 4 of 1.2 mm.

And, the top surface of this slipper 6 also has a plate thickness of 1.6 mm. A flat plate 12 made of a pagoda plate of m was attached.

The flower shape of this flat plate 12 had the same shape as the punched hole, and the outer shape was made to match the outer periphery of the stripper 6. punch 4
The gap C3 between the stripper 6 and the punch 4 is 0.05 mm, and the thickness of the stripper 6 is adjusted so that the top surface of the flat plate 12 and the two surfaces of the punch 4 are substantially flat.

As a result of inspecting the product punched by the cutting die configured as described above, it was found that the deformation of the periphery had been eliminated.

Note that the flat plates 11 and 2 are pasted in a predetermined shape, but if a punched plate punched with the punching die is used, a large number of slots can be formed, for example, in the iron core plate of a rotating electric machine. It is convenient for constructing a mold with a complex shape.

In this example, when the thickness of the product is 1.6 mm as in the example described in 4-2, the workpiece material is punched out, and the cut surface of the punched material is ground and the gap between the cutter and It is advisable to attach a flat plate with a small gap formed between the two.

In addition, in the case of the product plate thickness], , 6 rrtn, prepare a 1 m thinner hard steel plate, apply adhesive to the surface of the stripper, and punch the thin steel plate with this cutting die at the bottom dead center. You can also just stop it and glue it.

In this way, a steel plate thinner than the thickness of the workpiece is punched using a cutting die whose clearance between the blades is an appropriate value for the thickness of the workpiece (1.6+nm), so the cut surface is rounded and Since the contact area with the blade is small, frictional resistance is negligible. Inspection of the product obtained with the cutting die having the flat plate fixed in this manner revealed that there was no deformation of the periphery.

Further, the present invention can be constructed by selectively fixing a flat plate to each stripper. In other words, the flat plate is fixed only to the stripper on the side of the punched plate, which is the product of
It is optional to attach the stripper to the stripper on the side of the workpiece to be scrapped.

〔Effect of the invention〕

As explained above, in the present invention, a pair of punching blades consisting of a die and a punch are attached to a holder, and a stripper made of a plate material having rubber-like elasticity is provided at a position opposite to the die and the punch of each holder. In addition to fixing the
In this structure, a gap is provided between the stripper and the cutter to allow distortion of the stripper during punching, and since a flat plate covering the gap is fixed to the punching side surface of the stripper, deformation occurs at the periphery. This has the effect of making it possible to produce punched materials without blemishes.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a press cutting die showing an embodiment of the present invention;
Figure 2 is a cross-sectional view of the cutting die showing the state in which the upper die reaches the bottom dead center after punching the workpiece, and Figure 5 is a cross-sectional view of the cutting die showing the state in which the upper die reaches the bottom dead center after punching the workpiece, and Figure 5 shows the shape of the punched material when the upper die rises from the state shown in Figure 4. It is a sectional view of the cutting die showing how this occurs. 1-22...Holder, 3...Die, 4...
・Punch, 5, 6...Stripper, 11
, 12... flat plate. =8- Figure 1 Figure 2

Claims (3)

[Claims] (1) A pair of punching blades consisting of a die and a punch are attached to the holder, and a stripper made of a plate material having rubber-like elasticity is fixed to a position facing the die and punch of each holder, and the stripper and the blade are A press corrugated mold having a gap between the strippers to allow distortion of the stripper during punching, characterized in that a flat plate covering the gap is fixed to the punching side surface of the stripper. (2) The press corrugation mold according to claim 1, wherein the flat plate is fixed only to the stripper on the side of the punched material to be the product. (3) The press corrugated mold according to claim 2, wherein the flat plate is a punched material.