JPS6134894B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing metal slag by cold forming, and in particular, the cold forming improves the parallelism of both end surfaces, the flatness of both end surfaces, the perpendicularity between the outer periphery and both end surfaces, and the outer diameter. The present invention relates to a method for manufacturing a metal slug in the shape of a cylinder or a hollow cylinder, which can be formed with high accuracy such as coaxiality with the inner diameter.

Here, high-precision slag refers to the perpendicularity of the outer periphery 2 to one end surface 1, the parallelism with the other end surface 3, the flatness of each end surface 1 and 3, and the maximum outer diameter dimension as shown in FIG. It means a slug with little variation, and in the case of a hollow slug with a hole in the center, it means a slug with little variation in coaxiality between the outer diameter and the inner diameter in addition to the above-mentioned accuracy.

Such highly precise slugs are manufactured by cold forming a cylindrical metal material. Further, such slag is formed using case-hardened steel such as SCM415, and the product slag after forming is processed into various gears or high-precision cylindrical parts. Further, as the slag material, a forged material for gear forging is usually used, and for example, a forged material such as JIS standard SCM415, which is also case hardened steel, is used.

A typical example of a conventional method for manufacturing high-precision slag is described in Japanese Patent Application Laid-Open No. 125153/1983.

In this conventional method, a slag semi-finished product with a barrel-shaped outer periphery is formed in advance by pressurizing a cylindrical metal material from the top and bottom ends, and as shown in Fig. 2, the barrel-shaped slag semi-finished product is A slag product was obtained by a process in which the product 4 was pushed through a hollow mold 5 having an inner diameter smaller than the outer diameter of the product using a punch 6, and the outer periphery 7 of the semi-finished slag product was squeezed. For this reason, although it was possible to machine slag products with precision in the outer diameter, it was not possible to machine them with precision in terms of the parallelism of both end faces or the perpendicularity of both end faces with respect to the outer diameter. That is, the product slag obtained by the conventional method has, for example, a shape as shown in FIG. Not only was it unstable, but the outer diameter itself varied by about 0.1 mm, making it impossible to obtain a highly accurate slag suitable for machining precision parts such as gears. In addition, when punching a hole with a press punch using a conventional product slag as shown in Figure 3,
Due to poor flatness and large variations in outer diameter dimensions, coaxial precision of the inner and outer diameters could not be achieved.

The purpose of the present invention is to eliminate the drawbacks of the conventional methods and to form a high-precision slug in the form of a cylinder or hollow cylinder with excellent flatness, perpendicularity, and accuracy in outer diameter using cold forming. An object of the present invention is to provide a method for manufacturing metal slag.

The features of the present invention include the step of squeezing the outer periphery of a slag semi-finished product with a barrel-shaped outer periphery obtained by compressing a cylindrical metal material from the upper and lower end surfaces using a hollow metal, and simultaneously compressing the slag semi-finished product from the upper and lower end surfaces in this mold. That's true.

That is, according to the present invention, a process of pressurizing a cylindrical metal material from the upper and lower ends to form a slag semi-finished product with a barrel-shaped outer periphery, a hollow mold with an inner diameter smaller than the outer diameter of the barrel-shaped slag, and Provided is a method for manufacturing metal slag by cold forming, which includes a pressure punch and a counter punch that fit into the slag, and a step of squeezing the outer periphery and compressing the upper and lower end surfaces at the same time.

Furthermore, when forming the cylindrical hollow slug, in addition to the above steps, the slag is characterized by including a step of punching a hole in the center using the outer periphery of the slag that has been ironed with high accuracy while being constrained as a reference. A method for manufacturing metal slag by cold forming is provided.

Embodiments of the present invention will be described below with reference to FIGS. 4 to 11.

In carrying out the present invention, first, a cylindrical metal material 8 as shown in FIG. 4 is used, and its upper and lower end surfaces 9 and 10 are pressurized to form an outer periphery 11 as shown in FIG. A barrel-shaped slag semi-finished product 12 bulging outward in a bulging manner is manufactured. In this process,
The upper and lower end surfaces 13 and 14 are pressed using a high-precision press with extremely little collapse or misalignment even when pressurized.
Machining high parallelism between In addition, in the pressurizing process from the raw material 8 to the slag semi-finished product 12, processing can be performed at a large pressurizing rate, for example, 70
It is possible to compress with a processing rate of ~80%.

FIG. 6 is a diagram showing the process of cold forming the semi-finished slag product 12 into a solid cylindrical high-precision slag.

The cold forming apparatus 15 shown in FIG. 6 includes a hollow mold 16 having an inner diameter smaller than the outer mold of the product slag;
The hollow mold 16 includes a pressure punch 17 for pressurizing the upper end surface and a counter punch 18 for supporting the lower end surface of the slag semi-finished product 12.
The counter punch 18 is installed on a base 20 via a spring 21, and the counter punch 18 is urged upward by a spring 21. The reference numeral 22 indicates a knockout pin.

According to the molding device 15 shown in FIG. 6, a semi-finished slag product 12 is placed on a counter punch 18 which is suspended by a spring 21, and the slag semi-finished product 12 is placed on a counter punch 18 which is floated by a spring 21, and is pressed while being pressurized from the upper surface by a pressure punch 17 that fits into a hollow mold 16. Push into the hollow mold 16. This hollow mold 16
has a hollow part consisting of an inlet 23 formed by an inverted truncated cone-shaped taper part and a circular arc part 24, and as the pressure punch 17 is lowered, the slag semi-finished product 1
2 is guided and centered at the entrance 23 of the tapered part, and then the barrel-shaped outer circumferential part 11 is thereby squeezed by the arcuate part 24 of smaller inner diameter to a predetermined exact outer diameter. is formed. When the pressure punch 17 is pushed further, the counter punch 18 reaches the bottom surface (the top surface of the base 20) and stops. In this way, the barrel-shaped outer periphery 11 of the slag semi-finished product 12 is pressed to a predetermined size by the hollow mold 16, and both end faces are compressed by the pressure punch 17 and counter punch 18, so that it has a high outer diameter. A high-precision product slug can be obtained in which the parallelism and flatness of both end faces 1 and 3 (see FIG. 1) and the perpendicularity between these end faces and the outer periphery are formed with high precision.

Furthermore, when drilling a hole in the center of the high-precision slug 12 obtained by the apparatus shown in FIG. 6, the outer periphery of the product slug (outer periphery 2 in FIG. If the hole is punched in the center using a press punch (it is preferable to use a press punch such as that described in Japanese Patent Publication No. 53-8388), it will look like the one shown in Figure 7. A high-precision hollow cylindrical slug 25 is obtained.
This hollow slug 25 is processed by drilling holes while constraining the outer circumferential surface 2 with high precision, and the parallelism and flatness of both end surfaces of the product slug obtained by the cold forming apparatus shown in FIG. Since the perpendicularity is high, the degree of coaxiality between the inner diameter 26 and the outer diameter (outer circumference 2) shown in FIG. 7 can also be maintained extremely high.

According to the solid or hollow slag forming method described above, a highly accurate product slag with high precision in perpendicularity, parallelism, flatness, and outer diameter dimension and with little variation can be obtained. In particular, in the case of a hollow slug (FIG. 7), a high-precision slug with very little variation in coaxiality of the inner diameter and outer diameter can be obtained. Further, according to the above manufacturing method, a high-precision slag can be easily manufactured using the cylindrical metal material shown in FIG. 4 through a forming process that is entirely cold forming.

FIGS. 8 to 11 are diagrams showing other embodiments of the present invention.

FIG. 8 is a diagram showing a process of pressurizing a cylindrical metal material 8 from the upper and lower ends to obtain a semi-finished slag product having a barrel-shaped outer periphery. In this case, the shape of the pressing part 28 of the punch 27 is an inverted truncated cone shape. has been done. Code 29 is material 8
Shows the pedestal for installing the.

According to the process shown in FIG. 8, a semi-finished slag product 31 is obtained, as shown in FIG. 9, in which the outer periphery 11 is barrel-shaped and the upper end surface 13 is formed with a dish-shaped recess 30.

The semi-finished slag product 31 is formed into a high-precision slag 32 as shown in FIG. 10 by cold forming in a process similar to that of the previous embodiment described with reference to FIG. The upper end of this product slug 32 is a cylindrical high-precision flat part 33 that serves as the outer periphery.
and a central part 34 where precision is not required. The lower end surface 3 and the outer circumferential surface 2 are cold-worked to substantially the same shape and precision as the product slug produced by the forming method shown in FIG.

When further drilling holes in the product slug 32 shown in FIG. 10, as in the case of the above-mentioned embodiment, the outer circumference 2 is restrained and a press punch (see Japanese Patent Publication No. 53-8388) is used. A hole is punched out using a tool, and the material is cold-formed into the shape shown in FIG. In the hollow slug 35 shown in FIG. 11, the necessary upper end surface, lower end surface, and outer circumferential surface, except for the remaining portion of the recess 34, have high flatness, perpendicularity, outer diameter dimensions, and coaxial precision of inner and outer diameters. It is a precision molded product.

According to the embodiment described with reference to FIGS. 8 to 11, the compression surface is Since the area is smaller than the slag shown in Fig. 1, the pressurizing surface can be minimized, compared to the case of a pressurizing punch with a flat pressurizing surface as in the embodiments shown in Figs. 4 to 7. , the load can be reduced by approximately 20%. Therefore, especially when producing a large-diameter slug, it is possible to easily cold-form a large-diameter, high-precision slug using a press with a small press capacity.

As is clear from the above description, according to the present invention, a cylindrical or hollow cylindrical high-precision slag can be easily and reliably manufactured only by cold forming, and the resulting slag has a flat surface. Degree, parallelism, squareness, etc. can also be maintained with high accuracy.

[Brief explanation of the drawing]

Figure 1 is a partial cross-sectional side view of a high-precision slag (same as the slag obtained by the present invention), Figure 2 is a cross-sectional view of essential parts illustrating a conventional slag cold forming process, and Figure 3 is a conventional slag. 4 is a perspective view of a cylindrical metal material, FIG. 5 is a partial sectional side view of a semi-finished slag product with a barrel-shaped outer periphery, and FIG. 6 is a side view of a semi-finished slag obtained by the method of the present invention. FIG. 7 is a partially removed perspective view illustrating a hollow cylindrical high-precision slag obtained by carrying out the present invention, and FIG. FIG. 9 is a cross-sectional view of a main part illustrating a process of cold-forming a cylindrical metal material from the upper and lower end surfaces into a semi-finished slag product having a barrel-shaped outer periphery according to another embodiment of the invention.
FIG. 10 is a partially removed perspective view showing a semi-finished slag product with a barrel-shaped outer circumference obtained by the process shown in FIG. 9, which was obtained by using the semi-finished slag product shown in FIG. Partially removed perspective view of high-precision slug. FIG. 11 is a partially removed perspective view showing a high-precision hollow slug obtained by punching the product slag of FIG. 10. 1... Upper end surface, 2... Outer peripheral surface, 3... Lower end surface,
4... Slag semi-finished product with a barrel-shaped outer periphery, 5... Hollow mold, 8... Cylindrical metal material, 9, 10... Upper and lower end surfaces of the cylindrical metal material, 11... Barrel-shaped outer peripheral surface of the slag semi-finished product , 12... Slag semi-finished product, 13, 14...
... Upper and lower end surfaces of slag semi-finished product, 15 ... Cold forming device, 16 ... Hollow mold, 17 ... Pressure punch, 1
8...Counter punch, 25...High precision hollow slug, 26...Inner diameter of hollow slug, 27...Inverted truncated conical punch, 31...Slag semi-finished product, 36...
...Punch hole.

Claims (1)

[Claims] 1. A step of pressurizing a cylindrical metal material from the upper and lower ends to form a slag semi-finished product with a barrel-shaped outer periphery, a hollow mold with an inner diameter smaller than the outer diameter of the barrel-shaped slag, and A method for manufacturing metal slag by cold forming, comprising the steps of squeezing the outer periphery and compressing the upper and lower end surfaces at the same time using a pressure punch and a counter punch that fit together. 2. Claim No. 2, characterized in that the shape of the pressurizing part of the pressurizing punch used in the process of pressurizing a cylindrical metal material from the upper and lower ends to form a slug with a barrel-shaped outer periphery is an inverted truncated cone shape. The method for producing metal slag by cold forming according to item 1. 3. The process of pressurizing a cylindrical metal material from the top and bottom to form a slag with a barrel-shaped outer periphery, a hollow mold with an inner diameter smaller than the outer diameter of this barrel-shaped slag, and a pressurizing punch and counter fitted into the mold. a step of compressing the upper and lower end surfaces at the same time as tightening the outer periphery with a punch;
1. A method for manufacturing metal slag by cold forming, comprising the step of punching a hole in the center of the slag while restricting its outer diameter to form a hollow slag.