JPH0527218Y2 - - Google Patents

Description

[Detailed description of the invention] [Summary] The present invention is a method that reduces production costs and prevents accidents of punches falling by forming a stepped part on the punch of a press die whose both ends are machined into the same shape. This is a safe press die punch.

[Industrial application field]

The present invention relates to a punch for a press mold, and more particularly to a punch for a press mold in which a stepped portion is formed on any surface other than both ends.

[Conventional technology]

Press dies are used, for example, in blanking to punch sheet metal into various shapes, and are made up of an upper die (punch) and a lower die (die).

Conventional press die punches use milling to cut the tip of the sheet metal into the desired shape, thereby forming the punch.
However, milling requires time and processing costs are high.

Therefore, in recent years, so-called wire-cut electric discharge machines, which cut metal linearly while applying electric current to a wire and causing an electric discharge, have become popular, and punches for press molds are now machined using these machines. By using this wire cut electrical discharge machining, it has become possible to reduce machining costs and shorten machining time.

[Problem that the invention attempts to solve]

Fig. 3 is a perspective view of the conventional example, Fig. 4 is a sectional view explaining the problems of the conventional example, in which a is a diagram of the installed state, b is a diagram of the dropped state, and Fig. 5 is a diagram of another conventional example. This is a sectional view, in which 31a and 31b are end parts, 32 is a punch, 35 is a tap, 36 is a bolt, 37 is a punch plate, 38 is a stripper plate, 40 is a groove, and 41 is a pin.

As described above, conventional press die punches use wire cut electric discharge machining in order to reduce machining costs and shorten machining time. A punch formed by this means generally has a mounting tab 35 on the top of the punch 32, as shown in FIG. 4a.
It is fixed with bolt 36.

However, in wire-cut electrical discharge machining, the punch is cut into a linear shape, so as shown in FIG. 3, both ends 31a and 31b of the punch have the same shape (such a punch is also referred to as a straight punch). For this reason, if the fixing bolt becomes loose or breaks due to metal fatigue while the punch is in use, the punch 32 will be replaced by a stripper plate (the remaining sheet metal punched by the punch), as shown in FIG. 38, which serves to remove the mold from the mold by force, and fall onto the upper surface of the die of the lower mold (not shown).If you continue pressing without noticing the fall, the entire mold will be severely damaged, which is dangerous. Ta.

In order to prevent falling accidents, it is also possible to provide a groove 40 in the punch 32 and use a pin 41 to prevent the punch from falling as shown in Figure 5, but if the groove 40 is formed by milling etc., the cost and time will be reduced. There is a problem that it gets old.

The present invention was created in view of these points, and aims to provide a safe press die punch that can be manufactured at low cost and in a short time, and is safe from falling accidents.

[Means for solving problems]

The above problem is caused by a straight punch type press die punch whose upper and lower ends are wire-cut and electrical discharge machined into the same shape, and which punches out at the lower end. By providing a punch for a press die, the lower part of which is removed vertically to form a step part, and an accident of the punch falling is prevented by the step part being caught on a stripper plate. It will be resolved.

[Effect]

As shown in FIG. 1, the press die punch of the present invention has a press die punch 12 in which both ends 11a and 11b are machined into the same shape, and any surface other than both ends 11a and 11b of the punch 12 is The lower part 13 of the step part 14 is vertically removed to form a stepped part 14.

As shown in Fig. 1, the press die punch of the present invention is manufactured by wire cut electrical discharge machining, which processes both ends 11a and 11b into the same shape, so the processing cost is low and manufacturing can be done in a short time. is possible.

In addition, the lower part 13 of any surface other than both ends 11a and 11b of the punch 12 is vertically removed to form the step part 1.
4, so even if the fixing bolt etc. breaks and the punch falls, the stepped portion 14 will catch on the stripper plate of the upper mold (see Figure 2) and the punch will fall to the lower mold. It is possible to prevent this from happening.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention, and each of FIG. 2 is a sectional view showing a state in which the punch of this embodiment is prevented from falling, in which a is a diagram showing a state in which the punch is installed, and a diagram b is a diagram in a state in which it is falling.

In the figure, 11a and 11b are end parts, 12 is a punch, 13 is a lower part, 14 is a stepped part, 15 is a tap, 16 is a bolt, 17 is a punch plate, and 18
is a stripper plate, and 19 is a spring.

To explain the punch of this embodiment in accordance with the processing order, as shown in FIG. shape). The cut punch 12 has both ends 11a, 1
1b is a straight punch having the same shape. Wire cut electrical discharge machining can be performed at low cost and in a short time.

In this wire cut electric discharge machining, the shape of the mold is made larger than the actual mold shape by the amount of the lower part 13 shown by hatching in the figure. This is because this portion is necessary when removing the lower portion 13 and forming the stepped portion 14 in a later step. Although the means for removing the lower part 13 is not limited, in this example, the lower part 13 was vertically removed to a thickness of about 2 mm using a polishing means. This level of processing can be easily performed in a short time. By removing the lower portion 13, a stepped portion 14 of approximately 2 mm is formed, and a desired mold shape is obtained. Then, a tap 15 for attaching the upper mold is formed on the end portion 11a.

As shown in FIG. 2, pressing was actually performed using the punch of this example as described above.

In the state shown in FIG. 2a, the punch 12 is fixed to the upper die with bolts, and press working can be suitably performed. The stripper plate 18 serves to remove the remaining sheet metal punched by the punch from the mold by the repulsive force of the spring 19, and is formed along the shape of the punch 12. In this embodiment, as shown in FIG. 2b, by using this strut-ripper plate, even if the bolt 16 breaks due to metal fatigue or the like and the punch 12 falls, the stepped portion 14 formed on the punch 12 will remain in the strut-ripper plate. Accidents of getting caught on the edge of the plate 18 and falling can be prevented.

By preventing the punch from falling in this way, expensive molds will not be damaged, and work safety can be ensured.

[Effect of idea]

As mentioned above, the punch of the press die of the present invention uses wire cut electric discharge machining to process both ends into the same shape, and by providing a stepped part on a surface other than both ends, the punch can be punched at low cost and in a short time. It is possible to manufacture a punch that is safe and prevents falling accidents.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is a cross-sectional view showing a state in which the punch of this embodiment is prevented from falling, and Fig. 1 is a diagram showing a state in which the punch is installed, b is a diagram in a falling state, and Fig. The figure is a perspective view of the conventional example, and each figure in FIG. 4 is a cross-sectional view explaining the problems of the conventional example.
b is a diagram of a falling state, and FIG. 5 is a sectional view of another conventional example. In FIG. 1 and FIG. 2, 11a, 11b
12 is an end portion, 12 is a punch, 13 is a lower portion, 14 is a stepped portion, 15 is a tap, 16 is a bolt, 17 is a punch plate, 18 is a stripper plate, and 19 is a spring.

Claims (1)

[Claims for Utility Model Registration] In a punch 12 of a straight punch type press die in which an upper end 11a and a lower end 11b are wire-cut and electrical discharge machined into the same shape and the lower end 11b is punched, the upper and lower ends of the punch 12 are as follows: The step portion 14 is formed by vertically removing the lower portion 13 of any surface other than the portions 11a and 11b, and it is confirmed that an accident of falling of the punch 12 is prevented by the step portion 14 hanging on the stripper plate 18. Characteristic press mold punch.