JPS60191623A - Method of deburring hot forged product - Google Patents

Abstract

PURPOSE:To obtain accuracy of inner face of a hole as accurate as machining simultaneously with deburring by making press work using a specified punch having a burnished part. CONSTITUTION:Rake angle alpha in minus direction is provided in the blanking part at the tip of a punch 1. A burnishing part 3 larger in diameter than the blanking part 2 by allowance for burnishing is provided at the base end side of the blanking part 2. The blanking part 2 and burnishing part 3 are connected through a slanted tapered face. When a burred hole of a hot forged product is blanked using the punch 1, the burr and draft angle part are blanked by the blanking part 2, and at the same time, the inner face of the blanked hole is burnished by the burnishing part of the punch 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for deburring hot forged products.

Prior Art Conventionally, as shown in Fig. 1, the hot forged product α is
After removing the draft part C, the draft part C is removed by machining, which requires both press work to remove the burr and machining to remove the draft part C.
Processing is difficult.

Purpose of the Invention The present invention was made in view of the above-mentioned problems, and it is possible to improve the accuracy of the plate by machining the inner surface of the hole as well as deburring it by pressing using a punch, and to eliminate the need for machining. The purpose of the present invention is to provide a method for deburring hot forged products.

Constituent structure of the invention A punch having a punched part 2 and a punched part 3 connected to the punched part 2 with a tapered surface and whose diameter is slightly larger than that of the punched part 2! At the same time, the burr and draft portion of the hole having a burr of the hot forged product are punched out, and the inner surface of the punched hole is burnished by the burnishing part 3.

Punching and burnishing are done at the same time.

Example Embodiments of the present invention will be described based on FIG. 2 and subsequent figures.

In the figure, 1 is a punch, and a punched portion 2 at the tip of the punch 1 is provided with a rake angle α in the negative direction.

Note that the minus direction refers to the angle in the direction in which the tip is pointed.

A burnishing part 3 whose diameter is slightly larger than that of the punching part 2 by the burnishing allowance is provided on the base end side of the punching part 2. And the punching part 2 and the punching part 3
They are connected by a tapered surface with an inclination of about 100 degrees.

When punching a hole with a burr in a hot forged product using the punch 1 having the above configuration, the burr and draft portion are punched out in the punching portion 2, and at the same time, the inner surface of this punched hole is the burnishing portion of the punch 1. 3 will be burnished.

Below, the burnishing cost is 9 (Figure 3), 0.1■to,
2waw (Fig. 4), and each punch (Fig. 5) having a burnishing allowance of 0.1 and a land portion 4 having a smaller diameter than the burnishing part 3 on the base end side of the burnishing part 3. An example of a negative test is shown. The rake angle of each punch was -30°.

Test Results (a) Fractured Surface Ratio (Figure 6) By providing the burnishing allowance, the fractured surface ratio was reduced to less than the value when the burnishing allowance was zero.

The fracture surface ratio is the length of the fracture surface/(length of the test piece)
xlOO.

(6) Amount of burrs (Fig. 7) Contrary to the fracture surface ratio, the amount of burrs increases as the burnishing allowance increases.

(C) Surface roughness (Fig. 8) When the burnishing allowance was O, Iwon, a very good surface roughness was obtained due to the burnishing effect. Burnishing cost is 0.2
In the case of wm, the sliding resistance between the punch and the test piece increased, and the punch was more likely to seize, resulting in a worsening of the surface roughness.

(d) Parallelism (Figure 9) Parallelism was improved by providing a burnishing allowance.

(=) Flatness (Figure 10) When the burnishing allowance is O, +-, good flatness is obtained. When the burnishing allowance is 0.2 mm, it becomes worse due to the same reason as in the case of surface roughness. Conclusion From the above test results, by sizing the cut surface with a suitable punching allowance of less than O12, for example,
It was found that the fracture surface ratio, surface roughness, parallelism, and flatness were improved. The presence or absence of a land did not have much effect in this case. Also, the appropriate rake angle is in the range of 0 to -45 degrees. The reason why this rake angle is set to 0 to -45 degrees is as follows.

In other words, the surface roughness of the cut surface is directly transferred from the surface roughness of the bunch cutting edge, so using a punch with a shape that prevents the punch cutting edge from wearing out will improve the cutting surface accuracy, especially the surface roughness. . Therefore.

Increase the rake angle of the punch by +30゛ (Fig. 11), +20゛ (
Figure 12), 0' (Figure 13), -30' (Figure 14)
The results of testing in Examples 15-. The result is as shown in Figure 16. As is clear from this, the rake angle is 13
The closer the value is to 0, the less the amount of wear on the punch tip (first
It was found that the relationship between the amount of wear of the punch and the surface roughness of the cut surface at this time also showed that the surface roughness of the root cut surface improved as the rake angle approached -30' (Fig. 16). Figure) From the above test results, it is appropriate to set the rake angle in the range of 0 to -45°. Note that FIGS. 15 and 16 show the amount of wear and surface roughness after deburring 30 pieces.

Effects of the Invention According to the present invention, it is possible to obtain precision machining of the inner surface of the hole as well as deburring by press working using the punch 1, and to eliminate machining before the shaving process and to perform the machining after the deburring process. , Immediately No. 5 Bani/Ningage (depression) 79772 (City Fig. 9 Bani/Ningage (mm) Bani/Ningage Cmm)

Claims (1)

[Claims] A punch 1 having a punching part 2 and a punching part 3 connected to the punching part 2 with a tapered surface and having a slightly larger diameter than the punching part 2 is used to punch a hot forged product. A method for deburring a hot forged product, characterized in that the deburr and draft portion of a hole having a diameter are punched out, and the inner surface of the hole after punching is burnished in a burnishing part 3.