JPS62140800A - Die for punching - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a punching die having a die hole for a punch.

[Conventional technology]

When punching material by inserting the punch into the die hole, a vacuum is created between the contact surface between the punch and the material, so the punched plate punched from the material tends to stick to the punch surface, and this adhesion phenomenon can occur. If this occurs and the punching plate is ejected from the die hole or is driven and moved together with the punch, the material may be bruised or the die may be damaged.

Therefore, in the past, the following measures have generally been taken to separate the punched plate adhering to the punch surface.

(a) As shown in FIG. 4, a through hole (50a) is formed in the punch (50), and this through hole (50a)
A kiff force bottle (52) that can protrude and move from the punch surface toward the die (51) and a spring (53) that elastically biases the kicker pin (52) in the protrusion direction are provided inside.
Means for separating the punched plates by elastic protruding movement of the force pin (52).

(b) A means for separating punched plates using high pressure air by forming a flow path in the die to blow high pressure air toward the tip of the punch that has entered the die hole.

In the case of the former means (a), the force pin (52) and the spring (53) are assembled into the punch (50), which not only complicates the punch structure but also requires a lot of effort to manufacture. , tends to be expensive in terms of cost.Especially, punch (
The smaller the diameter of 50), the more likely the above-mentioned problem will occur.

In the case of the latter method (b), not only the passage processing for the die but also high-pressure air generating equipment such as a compressor is required, which not only increases the size of the entire device.
This tends to be costly, and in addition, since the pressure receiving area of the portion of the punched plate that protrudes radially outward from the punch outer circumferential surface is small, the punched plate attached to the punch surface may be separated incorrectly.

[Problems to be solved by the invention] The present invention has been taken into consideration in view of the above-mentioned circumstances, and
The purpose of this is to make it possible to reliably separate the punching plate from the punch surface by making simple and inexpensive modifications to the die hole.

[Means for solving problems]

A characteristic configuration of the punching die according to the present invention, which was taken to achieve such an object, is that the punching die is formed at a plurality of locations in the circumferential direction of the inner circumferential surface of the die hole, between this inner circumferential surface and the outer circumferential surface of the punch. The point is that the protrusion is formed smaller than the width of the clearance, and its functions and effects are as follows.

[For production]

Because the clearance between the protrusions formed at multiple locations in the circumferential direction on the inner circumferential surface of the die hole and the outer circumferential surface of the punch becomes narrow, the outer diameter dimension of the punched plate punched with the punch becomes smaller due to the second shear. During the return process of the punch, which has become a little larger and the large punching load has been released, the punching plate, which is about to return and move together with the punch, is moved by the local large diameter part of the punch and the inner circumferential surface of the die hole. It can be locked and separated from the punch.

Moreover, by configuring the clearance to be small in this way, the inner diameter of the part of the hole in the material that corresponds to the protrusion becomes slightly smaller, but since this small diameter part exists only locally in the circumferential direction, the clearance is reduced. Compared to the case where the entire structure is made smaller, the resistance to pull out the punch from the material can be made as small as possible.

〔Effect of the invention〕

Therefore, by simply forming the above-mentioned protrusions on the inner circumferential surface of the die hole, an hour wheel and inexpensive modification can suppress the increase in pull-out resistance of the punch and securely separate the punched blank from the punch. I was able to do it.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in Figures 1 to 3, a punch (3) is attached to a punch head (2) that can be driven up and down with respect to a die head (1).
The die (4) fixed to the die head (1) has a die hole (4a) for the punch (3).
), and a die hole (4
The protrusion (6) is smaller than the width (β) of the clearance (S) formed between the inner circumferential surface of a) and the outer circumferential surface of the punch (3).
) is formed.

Further, the inner circumferential surface of the die hole (4a) is provided with a tapered relief angle having a larger diameter on the lower side.

Then, since the clearance between the protrusions (6) formed at multiple locations in the circumferential direction of the inner circumferential surface of the die hole (4a) and the outer circumferential surface of the punch (3) becomes narrow, the punch (3) The outer diameter of the punched board (5a) becomes slightly larger due to the second shearing, and as a result, during the return process of the punch (3), where the large punching load is released, it returns to the same direction as the punch (3). The punching plate (5a) that is about to be moved is locked by its locally large diameter portion and the inner peripheral surface of the die hole (4a), and is reliably separated from the punch (3''F).

Moreover, by configuring the clearance to be small in this way, the inner diameter of the portion of the punched hole in the material (5) corresponding to the projection (6) becomes slightly smaller, but this small diameter portion is locally localized in the circumferential direction. Therefore, compared to the case where the entire clearance is made small, the material (5
) can be made as small as possible.

Next, to give an example of the dimensions of the protrusion (6) configured as described above, the outer diameter of the punch (3) is 10.0ψ, the die hole (
When the inner diameter of 4a) is 10.8φ and the width of the clearance (S) is 0.2 mm, the protrusion allowance of the protrusion (6) is set to 1/2 of the width of the clearance (S), and this protrusion (6) is formed into a circular arc shape of 0.15 to 0.2R.

In the above embodiment, the protrusion (6) is connected to the die hole (4a).
Although the punch (3) is formed in four places on the circumference, it may be formed in one place, three places, three places, or five or more places on the circumference. They may be formed continuously or intermittently in the direction of movement.

[Brief explanation of drawings]

1 to 3 show an embodiment of the punching die according to the present invention, FIG. 1 is a longitudinal sectional front view of the punching device, FIG. 2 is an enlarged plan view of the die, and FIG. 3 is an enlarged view of the main parts. FIG. FIG. 4 is a longitudinal sectional front view showing a conventional punching device. (3)...Punch, (4a)...Die hole, (5a)...Punching board, (6)...
Protrusion, (S)... Clearance.

Claims (1)

[Scope of Claims] [1] A punching die in which a die hole (4a) is formed for a punch (3), the inner peripheral surface of said die hole (4a) having a plurality of holes in the circumferential direction. A punching die in which a protrusion (6) is formed that is smaller in width than a clearance (S) formed between the circumferential surface and the outer circumferential surface of the punch (3). [2] The punching die according to claim 1, wherein the protrusion margin of the protrusion (6) is 1/2 of the width (l) of the clearance (S). [3] The punching die according to claim 1, wherein the protrusion (6) is a continuous protrusion along the axial direction of the die hole (4a).