JPH0354017B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Purpose of the Invention [Field of Industrial Application] This invention provides a method for manufacturing a precision punching die that can punch out extremely delicate and thin materials such as metal amorphous and magnetic tape with high dimensional accuracy. It is related to.

[Prior Art] A punching die is a die used for punching, and as shown in FIG. 2, it is equipped with a male punch 102 and a female die 103. The shaped work material 104 is passed through the die 103.
the die 103 by lowering the punch 102.
The material to be processed 104 is sheared and punched into the shape of the mold.

In precision punching, which requires particularly high dimensional accuracy even in such punching processing, the clearance C between the punch 102 and the die 103 when inserted into the die 103.
The closer C is to zero, the better, and normally this clearance C must be kept within several percent of the thickness of the workpiece material 104.

However, when processing extremely delicate thin materials such as amorphous metal or magnetic tape with high dimensional accuracy, a few percent of the material's thickness must be
On the other hand, since the dimensions of punches, dies, their fixtures, etc. each have errors on the order of μm, it is normal to combine them to produce a precision punching die with the desired clearance. This method is not possible.

Conventionally, the following methods were used to make precision punching dies.

In other words, the die is molded and hardened to the desired dimensions using the usual method, and then set in a press machine.
On the other hand, the punch is formed slightly larger than the die and set in its unhardened state, and the tip of the punch is slightly inserted into the set die, and only the tip of the punch is shaved to match the die dimensions. Later, this punch is removed and the entire piece is ground to match the dimensions of the tip, then hardened and reset.

Alternatively, instead of putting only the tip of the raw punch into a die, the entire punch is put into a die, cut to fit the die, and used as a punch in its set raw state.

[Problem to be solved by the invention] However, in the former case, the dimensions of the punch and die are matched by an indirect method in which only a part of the tip of the punch is matched with the die, and the rest follows suit. Since the punches are removed and re-set, errors also occur here, making mold manufacturing a laborious and time-consuming task that requires repeated redoing and adjustment.

In the latter case, although there is no error caused by resetting the punch, there is a drawback that the life of the punch is short because the punch is used raw without being hardened.

This invention was made in view of the above-mentioned circumstances, and it is an object of the present invention to reliably and easily manufacture precision punching dies that allow for highly accurate dimension matching of punches and dies, and eliminate the need for removal and resetting. The purpose of this paper is to provide a method for manufacturing precision punching dies.

(b) Structure of the Invention [Means for Solving the Problem] Corresponding to this objective, the method for manufacturing a precision punching die of the present invention provides a method for manufacturing a precision punching die that uses one of a punch and a die having an inner diameter smaller than the outer diameter of the punch. is assembled into a press device with the other one being hardened and the other unhardened, and then the punch is inserted into the die in the assembled state and one of the two is ground to match the diameter of the other, and then the assembled part is assembled into a press device. It is characterized in that the other unhardened cutting edge portion is hardened in a state where the cutting edge is hardened.

Hereinafter, details of the present invention will be explained with reference to the drawings showing one embodiment.

Figure 1 a, b, c, d and e are precision punching molds 1
It shows the manufacturing method.

First, prepare punch 2 and die 3. The punch 2 is hardened after forming and has an outer diameter R. The die 3 has an inner diameter _r1 slightly smaller than the outer diameter R of the punch, and is in an unhardened raw state. And prepared punch 2
Then, an assembling step is performed in which the die 3 is assembled facing a press mold (not shown) (FIG. 1a).

Next, insert the punch 2 into the die 3 while it is assembled in the press device, and use the hardened punch 2 to scrape the unhardened inner peripheral edge 3a of the die.
(FIG. 1b), and a diameter matching step is performed to match the inner diameter of the die 3 to the outer diameter of the punch 2 (FIG. 1c). Through this diameter matching process, the die 3 becomes the die 13 with an inner diameter r ₂ , r ₂ is almost equal to R, and the punch 2 and die 1
The clearance between 3 and 3 is approximately equal to zero.

Next, with the punch 2 and the die 13 assembled in the press device, the punch 2 is raised to remove the die 13.
A hardening step is performed to harden the cutting edge portion 13b of the die 13. In this hardening process, for example, the cutting edge portion 13b of the die 13 is locally heated with a heat source 4 such as a gas burner or a laser to become red hot (first
d), and then pressing absorbent cotton 5 or the like soaked in water against this cutting edge portion 13b.
After the quenching process, the die 23, including the cutting edge portion 23b, has an inner diameter _r3 that is almost unchanged from _r2 , and this is because heating and cooling are limited to only the cutting edge portion 13b, which is a very small part of the die 13. This is because, since it can be carried out locally, high heat is not conducted throughout the die 13, and the portion 13c, which occupies most of the die 13 other than the cutting edge portion 13b, is not changed at all.

In the embodiment described above, of the punch 2 and the die 3, the punch 2 is hardened and the die 3 is unhardened, but conversely, the die is hardened and has a predetermined inner diameter, while the punch 2 is hardened and the die 3 is unhardened. As an unhardened punch with an outer diameter larger than the die, it can be incorporated into a press device and the punch can be ground by the die to match the diameter to the die.

[Function/Effect] In the method for manufacturing precision punching dies configured in this way, the die that is initially assembled into the press device has a diameter only slightly smaller than that of the punch, but the unhardened one is replaced by the hardened other. The diameters of both are matched by cutting, and in this assembled state,
Because the unhardened edge of the blade is locally hardened without having to be removed, there are no dimensional errors and the clearance is almost zero.
Durability is added while the diameter remains the same.

As is clear from the above description, according to the present invention, the dimensions of the punch and die can be matched with high precision, and there is no need for removal and resetting, and precision punching dies can be manufactured reliably and easily. A method for manufacturing precision punching dies can be obtained.

[Brief explanation of drawings]

Fig. 1 shows the manufacturing method of the precision punching die of the present invention, in which a is a longitudinal cross-sectional view showing the assembly process, b is a vertical cross-sectional view showing the diameter adjustment process, and c is a diagram showing the punch and die after the diameter adjustment process. d is a vertical cross-sectional view showing the quenching process, e is a vertical cross-sectional view showing a completed precision punching die, and FIG. 2 is a vertical cross-sectional view of a conventional precision punching die. 1... Precision punching die, 2... Punch, 3... Die, 3a... Inner peripheral edge, 4... Heat source, 5... Absorbent cotton soaked with water, 13... Die, 13b... Cutting edge part, 23...Die, 23b...Blade tip, 101...
... punching die, 102 ... punch, 103 ... die, 104 ... material to be processed.

Claims (1)

[Claims] 1. A punch and a die having an inner diameter smaller than the outer diameter of the punch, one of which is hardened and the other unhardened, are assembled into a press device, and then the punch is inserted into the die in the assembled state. A method for manufacturing a precision punching die, comprising: cutting one of the two to match the diameter of the other, and then hardening the unhardened cutting edge of the other in the assembled state.