JPH0216815Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to a punching device using a punch and a die.

(Conventional technology) Conventionally, a punching device using a general press machine is
As shown in FIGS. 4 and 5, it is equipped with a punch 11 and a die 12, on which a material 13 made of a metal plate is set. The die 12 also has a punch hole 14 into which the punch 11 can be fitted while maintaining a predetermined clearance α on its outer periphery.
The punched hole 14 is set with a predetermined relief angle β that tapers toward the punching direction by the punch 11 (downward in FIG. 4). 16 is a stripper, which removes the material 13 from the punch 11;
Prior to punching, the material 13 is pressed and fixed by a spring 17.

When punching is to be performed, the punch 11 is lowered in the direction of arrow P, as shown in FIG. At this time, part A of the material 13 is exposed to the stripper 1 from above.
6 and is received from below by the die 12, so that it does not move even when the punch 11 is lowered. Therefore, only the part B, which becomes the punching scrap, is punched out by the punch 11, and it descends into the punch hole 14 together with the punch 11 and is removed.

By the way, during the above-mentioned punching operation, punching shards sometimes bite into the punch 11, and once the punch 11
If the material that has descended into the punching hole 14 along with the punch 11 protrudes from the punching hole 14 of the die 12 as the punch 11 returns and rises, or if the punched scraps tilt and cause scrap clogging, the product will be defective. The mold may be damaged.

At this time, although a clearance angle β is formed in the punch hole 14 of the die 12, simply providing the clearance angle β cannot prevent scum from climbing up and clogging. In other words, when the punch hole 14 is provided with a clearance angle β, the upper end of the punch hole 14 of the die 12 exerts the maximum biting force against the punched chips, but the punch hole 14 of the die 12 has a maximum biting force depending on the clearance angle β. Biting power gradually disappears.

Therefore, it is good if the punched chips are aligned in a superposed manner in the punching direction in the punching hole 14, but the punched chips that have lost their biting force against the punching hole 14 of the die 12 are likely to fall down, and eventually become scraps. This will lead to clogging and debris clogging.

On the other hand, as shown in Japanese Patent Publication No. 47-44109, one or more spiral grooves or inclined grooves having an inclination angle with respect to the punching direction are formed on the inner periphery of the punch hole 14 of the die or the outer periphery of the punch. It is proposed that a

However, if a spiral groove or an inclined groove having an angle of inclination with respect to the punching direction is provided in the punching hole of the die, a tilting force will always act on the punched chips, which will encourage the phenomenon of the punched chips falling over. Easy to cause sludge build-up and sludge clogging.

Furthermore, the spiral groove or inclined groove provided in the punching hole acts as a cutting edge, causing a phenomenon similar to secondary shearing in this area, resulting in extremely high punching pressure and strain on the mold. Becomes easily damaged. Note that providing a groove on the punch will affect the shape of the product,
It cannot be applied to punching precision punched parts.

(Problems to be Solved by the Invention) As described above, in the conventional punching device, there are still problems with scrap lifting and scrap clogging.

An object of the present invention is to provide a punching device that reliably prevents scrap build-up and scrap clogging, thereby preventing the production of defective products and damage to the mold.

[Structure of the invention] (Means for solving the problems) The present invention has a punch that can be fitted to the outer periphery of the punch with a predetermined clearance, and that can be fitted in a predetermined direction in the punching direction by the punch. In a punching device equipped with a die having a punched hole that expands in a tapered shape due to a clearance angle, a punched part is punched on the inner surface of the tapered punched hole of the die without having a clearance angle and within the range of the clearance. A plurality of protruding stripes having contact portions with the punch are provided along the punching direction with the punch.

(Function) In the present invention, on the inner surface of the punched hole having a clearance angle of the die, a plurality of protrusions having contact parts with the punched part within a predetermined clearance range are formed along the punching direction by the punch. This is to prevent scraps from climbing up from the die and clogging due to the scraps falling over.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In addition, in the following examples, the basic configuration is as follows:
Since it is the same as that shown in FIGS. 4 and 5, corresponding parts are given the same reference numerals and detailed explanation will be omitted.

As shown in FIGS. 1 and 2, a plurality of uneven portions 18 are integrally formed on the inner surface of a punch hole 14 formed in a die 12 along the punching direction by the punch 11. As shown in FIGS. In this embodiment, the punch hole 14 is square, and the clearance angle β having a triangular cross section is formed as the uneven portion 18 along the punching direction by the punch 11 at the center of each of the four sides forming the inner surface of the punch hole 14. Convex strips 19 without any ridges are provided in parallel.

Then, part A of the material 13 is pressed and fixed on the die 12 with the stripper 16, and the punch 11 is moved to the arrow P.
When it is lowered in the direction of , only part B, which will become the scrap, is punched out by the punch 11, and it descends into the punch hole 14 together with the punch 11, but the inner surface of the punch hole 14 has a plurality of protrusions 19. Since it is formed along the direction of punching by the punch 11, the punching chips that have descended into the punching hole 14 bite into each of the protrusions 19.
Therefore, even if the punch 11 is returned and raised, the punched chips will not stick out onto the die 12. In this way, the biting force of the punched scraps against the punched hole 14 of the die 12 is kept constant without being affected by the clearance angle β, and the protruding strip 19 serves as a guide for the punched scraps, giving them enough space to tilt with respect to the punched scraps. Therefore, clogging due to tilting does not occur.

In addition, when punching is performed as described above, the shape of the product is approximately the same as that of the punch 11, and the shape of the punched shavings is approximately the same as that of the punched hole 14 of the die 12. Therefore, even if the protruding portion 19 is provided, the shape of the product is not affected.

Next, FIG. 3 shows another example of the uneven portion 18 on the inner surface of the punch hole 14.
Punch 11 at the center of each of the four sides forming the inner surface of
A convex strip 20 having a constant width and a rectangular cross section without the relief angle β is provided along the punching direction. In this way, by providing the straight convex strip 20 with a rectangular cross section, the biting force of the scraps is strengthened.

[Effect of the invention] According to the invention, in the inner surface of the punched hole of the die having a clearance angle, the inner surface of the tapered punched hole of the die along the punching direction has no clearance angle and the range of the clearance described above. Since a plurality of convex portions each having a contact portion with the punched portion inside are provided along the punching direction by the punch, the punched scraps bite into the convex portions within the punched hole when punching with the punch. Even when the punch is returned and raised, the scraps that protrude from the die do not rise. Therefore, the biting force of the punched scraps against the punched hole of the die can be kept constant without being affected by the clearance angle. The convex part acts as a guide for the punched chips and does not give the punched chips any room to tilt.Therefore, there is no chance of chip clogging due to tilting, which effectively prevents defective products and mold damage. can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the punching device according to the present invention, FIG. 2 is a plan view of the die in FIG. 1, and FIG. 3 is a plan view of the die showing another embodiment of the present invention. FIG. 4 is a sectional view of a conventional punching device, and FIG. 5 is a plan view of the die in FIG. 4. 11... Punch, 12... Die, 13... Material, 14
... punch hole, 18 ... uneven portion, 19, 20 ... convex stripe, α ... clearance, β ... clearance angle.

Claims (1)

[Scope of utility model registration request] A punching device comprising a punch and a die having a punch hole into which the punch can be fitted with a predetermined clearance on its outer periphery and which expands in a tapered shape with a predetermined clearance angle toward the punching direction by the punch. In the punching device, on the inner surface of the tapered punching hole of the die,
A punching device characterized in that a plurality of convex stripes having no relief angle and having contact portions with the punching material within the range of the clearance are provided along the punching direction by the punch.