JPH0134689B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a punching die for ultra-thin plate material comprising a punch and a die.

[Prior art]

2. Description of the Related Art In recent years, parts made of ultra-thin plate materials, such as springs, connectors, contacts, etc., have become widely used in the mechanical and electrical equipment industries.

The etching method and press punching method are used as production methods for these ultra-thin plate products.
Etching is often used because it is not easy to produce press punching dies for ultra-thin plates.

However, since the press punching method has high productivity and there are no difficulties regarding waste liquid treatment, there is an increasing desire to adopt the press punching method.

[Problem that the invention seeks to solve]

The technical difficulty in creating press punching dies for ultra-thin plates lies in the fact that the clearance between the punch and the die must be made extremely precise and extremely small.

For example, if the plate thickness is 50 μm, the punch/die clearance must be approximately 10% of the plate thickness (ie, approximately 5 μm). However, a clearance of 5 μm must be maintained around the entire circumference of the punched contour.

Dice like this with almost zero clearance.
As a known technique for making punches, there are the following methods.

That is, (a) the die is made of cemented carbide, and (b) the punch is made of tool steel, and the punch is made somewhat larger than the die. (c) Press the punch above into the die and sharpen the punch with the die.

The above conventional methods also have various difficulties, especially:
Because the punch is scraped off with a die,
The precision of the preparation of both members (dimensional precision of making the punch larger than the die) must be high.

The present invention was made in view of the above circumstances, and
It is an object of the present invention to provide a method for quickly and easily producing a punch die consisting of a punch and die with almost zero clearance without requiring ultra-high precision machining.

[Means for solving problems]

In order to achieve the above object, the method for manufacturing a punching die for ultra-thin plates according to the present invention comprises a punch and a die having a clearance from each other, and the tip of the punch faces the inlet of the die. Peening is performed near the entrance of the die to plastically deform the surface of the die, and then the plastically deformed portion is polished to reduce the clearance between the inside diameter of the die entrance and the outside diameter of the punch to almost zero. It is characterized by tightening.

[Effect]

When the above operation is performed, the entrance portion of the inner diameter of the die, which has been made in advance to have a larger diameter than the outer diameter of the punch, is plastically deformed by peening and the diameter is reduced. By appropriately grinding this, the desired result (a punch and die set with almost zero clearance) can be obtained.

〔Example〕

Next, an embodiment of the method of the present invention will be described with reference to FIGS. 1 to 4 in sequence.

FIG. 1 is an explanatory diagram schematically depicting a state in which the preparatory operations have been completed in this embodiment, and a punch 1 and die 2, which have undergone preliminary processing as described later, are mounted on a press device 3.

3a is the base of the press, 3b is the head,
Similarly, 3c is a guide shaft.

FIG. 2 shows a vertical cross section of the punch 1 and die 2 facing each other. The clearance c between both members does not require ultra-high precision, but is configured to be as small as possible within the precision range of a normal micrometer (for example, on the order of 1/100 mm).

Next, as shown in Figure 3, insert the tip of punch 1 into die 2.
facing the entrance.

In the present invention, the word "close" means that the tip is slightly inserted or slightly separated.
In addition, in FIGS. 2 and 3, the clearance dimensions are enlarged and exaggerated compared to the actual size for the convenience of reading.

A rubber tubular cover 4 is fitted around the outer periphery near the tip of the punch 1 (excluding the tip end) to protect this part, and the area around the die hole on the surface of the die 2 is inserted as shown by arrows A and A'. Perform shot peening.

FIG. 4 is an explanatory diagram schematically depicting the state after processing, and phantom lines 1 and 2 indicate the punch shape and die shape before peening processing. The solid lines 1 and 2 represent the punch and die shapes after peening. However, for ease of reading, the amount of deformation due to peening is enlarged and exaggerated.

The inlet portion of the die 2' is plastically deformed B, B' into an inwardly recessed shape by peening. The surface of this die 2' is removed by polishing down to the D-D plane, and a sharp blade is provided at the entrance.

On the other hand, the vicinity of the tip of the punch 1' (the part exposed from the cover 4) has been worn due to shot peening, so the tip surface is polished to remove it down to E-E, and a sharp blade is attached to the edge.

Through the above operations, the inner diameter of the die is reduced at the entrance and a sharp blade is provided, and a sharp blade is also provided around the tip of the punch. As the diameter of the die is reduced, the clearance to the punch becomes almost zero.

The sharp blade formed at the die inlet as described above does not have a very high mechanical strength, but since the workpiece is an extremely thin plate, it can exhibit sufficient durability for practical use.

〔Effect of the invention〕

As explained above, according to the method of the present invention,
It has the excellent practical effect of being able to quickly and easily construct punches and dies with almost zero clearance without the need for ultra-high precision machining, and is suitable for press punching in the industrial production of ultra-thin sheet parts. It has contributed greatly to the practical application of the law.

[Brief explanation of drawings]

FIG. 1 is an explanatory view schematically depicting a ready state in one embodiment of the method of the present invention, and FIG. 2 is a sectional view of the vicinity where the punch and die are opposed. FIG. 3 is an explanatory diagram of one embodiment of the method of the present invention,
FIG. 4 is also an explanatory diagram of the action and effect. 1, 1'...Punch, 2, 2'...Dice, 3...Press device, 4...Cover.

Claims (1)

[Claims] 1. A method for producing a punching die for an ultra-thin plate consisting of a punch and a die, in which the punch and die have a clearance from each other, and the tip of the punch faces the entrance of the die. Peening is performed near the entrance of the die to plastically deform the surface of the die, and then the plastically deformed portion is polished to almost reduce the clearance between the inside diameter of the die entrance and the outside diameter of the punch. A method for making a punching die for ultra-thin plates, which is characterized by zero-leveling. 2. When performing the peening process, the outer circumference near the tip of the punch is covered with a cover member, and the tip of the punch is ground and removed after the peening process. A method for manufacturing a punching die for ultra-thin plates.