JPS601849Y2 - press punching die - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in the structure of a press punching die, specifically a press punching die for punching diagonal holes.

A method is currently proposed that uses a punch and die to drill diagonal holes in the workpiece. For example, if this method is applied to machining the ventilation holes of field coils for direct-cooled turbine generators, it will be possible to make diagonal holes in the workpiece using a punch and die. Compared to using NC milling, the number of machining steps can be significantly reduced.

However, such conventional press punching dies for punching diagonal holes have the disadvantage that the life of the dies is extremely short because the punch and the die come into contact with each other violently.

The purpose of this invention is to eliminate the drawbacks of the conventional press punching dies as described above, and to provide a press punching die for diagonal hole punching that has a long die life by preventing the punch and die from coming into contact with each other.

In order to achieve this objective, the inventors conducted various tests to determine the cause of shortening the life of the press punching die, and found that the punch was deflected in the direction perpendicular to the stroke of the punch during the diagonal punching process.

It was confirmed that this deflection of the punch caused the punch and die to come into contact with the mold, and as a result, abnormal bending stress was generated in the punch, causing damage to the punch tip and shortening the life of the mold.

Therefore, in this invention, the clearance between the punch and the die is changed depending on the location, and a clearance corresponding to the maximum deflection of the punch is provided in areas where there is a risk of mold contact, thereby preventing the occurrence of mold contact.

This will be explained in detail below using figures.

FIG. 1 shows a schematic sectional view of an embodiment of this invention.
is the shank, 2 is the temporary press cylinder, 3 is the punch plate, 4 is the guide, 5 is the ram, 6 is the punch, 7 is the temporary press,
8 is a workpiece, 9 is a die, 10 is a die plate, 11 is a bolster, and 12 is a spacer, which is constructed in the same manner as a conventional press punching die.

Then, the punch 6 and die 9 have a structure as shown in Fig. 2,
A larger clearance is provided between the punch 6 and the die 9 by the amount of deflection of the tip of the punch 6, which has been confirmed in advance by test results.

That is, in FIG. 2, the locus drawn by the tip of the punch when diagonally punching a hole in the workpiece 8 is shown by a broken line 13, and the die 9 is structured to have a clearance corresponding to the locus drawn by the tip of the punch.

Naturally, the amount of deflection of such a punch varies depending on the shape and material of the punch, the inclination of the diagonal hole, and the thickness and material of the workpiece.Examples are listed below to clarify the present invention. .

Example 1 Fig. 3 shows an explanatory diagram of an embodiment of the present invention, and the punch 6 is made of material 5KH-9 and has a cross-sectional shape (width W = 5.6 oblique, length L
= 33.0 mm), the thickness t of the workpiece 8 was 7.2 mm, and the inclination angle θ of the diagonal hole was 60'.

The maximum amount of deflection of the punch tip (acute angle part) at this time is 1.3
1. Clearance of punch and die for that part.
It was set to 5mm.

Example 2 Under the same conditions as Example 1, the thickness of the copper plate of the workpiece was 8.5 mIrL.
When, the maximum amount of deflection is 1.4TIr! ft, and the clearance was set to 1.6mm.

Now, a diagonal hole (
Width 5.541rr! n x length 33rIr! Comparing the conventional diagonal hole punching die and the die structure of the present invention in the case of press punching (n1 semicircular at both ends), it was found that with the conventional one, the punch broke after about one punch, but this In the case of invention, the cutting edge of the punch and die is polished to approximately 10%.
No abnormalities were observed even after 1,000 uses, indicating that the product could withstand semi-permanent use.

As is clear from the above description, according to this invention, it is possible to prevent the punch and the die from coming into contact with the mold, thereby preventing the punch from being damaged and having the effect of significantly extending the life of the mold.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the present invention showing the locus of the tip of the punch, and FIG. 3 is an explanatory diagram showing the relationship between the punch and the workpiece. 3... Punch plate, 4... Guide, 6... Punch, 7... Temporary presser, 8...
...Work material, 9...Die.

Claims (1)

[Scope of utility model registration request] In a press punching die that is equipped with a punch and a die for drilling diagonal holes in a workpiece, the clearance between the punch and the die is set to be larger by the amount of deflection at the tip of the punch at the portion where the punch is deflected. Features a press punching die for diagonal hole punching.