JPS6010744Y2 - carbide punch - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a carbide punch in which a carbide sleeve and a shank are assembled by fitting a shank insertion part into a carbide sleeve and then tightening the punch.

Conventionally, a carbide punch used for cold drawing, etc. is made by inserting the shank fitting part 2 The structure is such that the sleeve 1 is tightened and fixed.

In these conventional types, during use, the temperature of the material and punch rises to 50 to 100°C due to heat generation due to plastic deformation of the material and heat generation due to friction between the material and the punch, etc., and is processed in a thermally expanded state. Ru.

At this time, the coefficient of thermal expansion of the steel material used for the shank member is usually larger than that of the carbide material, so depending on the rising temperature, more internal pressure than necessary may be applied to the carbide sleeve, resulting in a tool lifespan. is affected.

Further, there was a problem in that when the temperature returned to room temperature after completion of processing, the dimensional accuracy of the product varied greatly, making it impossible to obtain the desired product.

This invention does not reduce the structural strength of the carbide punch.
This is an attempt to solve the above problem by creating a structure that cools the inside more effectively.

Next, the present invention will be explained in detail based on the drawings.

An embodiment of the present invention is shown in FIGS. 2 and 3.

FIG. 2 is a longitudinal sectional view, FIG. 3 is an external view of the shank, and arrows in the figures indicate the flow direction of the cooling medium.

By fitting the shank fitting part 2y of the steel shank body 2 into the sleeve inner small-diameter working part 1b of the carbide sleeve 1, fitting the stop ring 3 into the sleeve inner large-diameter stepped part 1a, and tightening the bolt 4, the stop ring is removed. 3 is tightened to the shank insertion part 2y.

Therefore, when the bolt 4 is tightened, the stop ring 3 pushes the sleeve shoulder 1C of the carbide sleeve 1 in the direction of tightening the bolt, while one end surface of the carbide sleeve 1 is fixed to the shank shoulder 2h.

Therefore, the carbide sleeve is restrained from moving in the axial direction of the carbide punch by the stop ring and the shank shoulder, and is tightened and fixed to the shank.

A groove through which a cooling medium such as cooling water flows is provided on the outer surface of the shank insertion portion 2y.

The cooling medium is supplied through the cooling medium supply hole 2 provided inside the shank.
a, passes through the communication hole 2b, cools the carbide sleeve 1 from the inside by going around the ring-shaped groove 2C provided on the outer surface of the shank insertion part, and the spiral 1l12d.
It gathers in a ring-shaped R2e, passes through the communication hole 2f, and exits the discharge hole 2.
It is discharged from g.

When using the conventional carbide punch shown in Figure 1, the temperature rise change during use is 20 mm for a punch diameter of 100 mm.
°C, :! It becomes 100℃, and the dimensional change of the product due to this is 0.09677+77! becomes.

-When using the carbide punch devised by a second-hand book, the temperature change is 20℃
= 40°C, and the dimensional change of the product due to this is 0.
0.024 mm, making it easier to obtain the desired product quality.

As a result, during the drawing process, the shank fitting part thermally expands and the action of forcibly expanding the carbide sleeve from the inside does not occur, so the service life of the sleeve is not shortened.

In addition, in the present invention, the shank fitting part is fitted into the hardening sleeve, the carbide sleeve and the shank are tightened and fixed by a tightening means, and a groove is provided between the shank fitting part and the carbide sleeve through which the cooling medium flows. Not only is it easy to form the medium flow grooves, but the cooling medium can be passed evenly along the heat-generating surface, over a long flow path, and in close proximity, making effective cooling possible.

Furthermore, since the groove for passing the cooling medium is only partially provided between the hardening sleeve and the shank fitting part, there is no major change in the structure in which the shank fitting part supports the sleeve, and therefore it is superior to the conventional structure. Compared to hard punches, it has the advantage that the reduction in structural strength due to cooling means is not particularly large.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a conventional carbide punch, FIG. 2 is a vertical cross-sectional view of an embodiment of the present invention, and FIG. 3 is an external view of a shank used in the present invention. 1... Carbide sleeve, 1a... Large diameter stepped part on the inner surface of the carbide sleeve, 1b... Small diameter stepped part on the inner surface of the carbide sleeve, 1c...・Carbide sleeve shoulder,
2...Shank body, 2a...Cooling medium supply hole, 2b, 2f...Communication hole, 2c, 2e
...Ring groove, 2d...Spiral groove, 2g...Drain hole, 2h...Shank shoulder, 2y...Shank insertion Part, 3...
...stop ring, 4...bolt.

Claims (1)

[Scope of utility model registration request] The shank fitting portion is inserted into the carbide sleeve and the carbide sleeve and shank are assembled by a tightening means, and a coolant inlet hole bored inside the shank;
A carbide punch characterized in that a discharge hole, a communication hole chimney, and a pisil groove provided over the entire fitting contact surface of the shank fitting portion with the sleeve are successively communicated to form an elongated coolant flow path.