JPH0428443A - Manufacturing method for forging materials - 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 [Industrial Application Field] The present invention relates to a method for manufacturing a forging material for forming a forging material from a rod-shaped material.

[Conventional technology]

Conventionally, as shown in Fig. 4, a method for producing a disc-shaped forging material used in forging involves moving a bar-shaped material C in the vertical direction between an upper mold a and a lower mold with flat pressurizing surfaces. The material C can be produced by applying more pressure, or by storing the material C in a cavity d provided in the lower mold and pressurizing the material C with the upper mold a, as shown in Fig. 5. A restrained upsetting method in which molding is performed while restraining the surroundings, or as shown in Fig. 6, the upper part of the material C is accommodated in the cavity e provided in the upper mold a An upsetting method is known in which the material C is pressurized and formed by a punch a'.

[Problem to be solved by the invention]

However, in the method shown in Fig. 4 or Fig. 6, the material C is not restrained, so the resulting forging material has poor roundness, and when it is forged, there is a problem such as lack of thickness, which causes defective products. was there.

In addition, in the method shown in Fig. 5, when the material C is set in the cavity of the lower mold, the material C is not necessarily placed in the center of the cavity d, which causes variations in the thickness of the obtained forging material. When this was forged, the inner diameter and outer diameter of the product were eccentric, resulting in a defect that resulted in defective products.

This invention was made to improve the above-mentioned problems, and it is an object of the present invention to provide a method for manufacturing a forging material that can obtain a forging material having a uniform thickness and roundness.

[Means and operations for solving the problem] In order to achieve the above object, the present invention inserts the lower part of a rod-shaped material into a cavity of a lower mold that is elastically supported by a guidance, and aligns the center of the cavity with the material. In this state, the upper mold is lowered and molding is started from the upper side of the rod-shaped material between the fixed lower punch which has a protrusion on the upper part provided in the cavity of the upper mold and the lower mold, and then the upper mold is lowered. By pressing the mold against the lower mold and closing the cavity of the upper mold, the lower mold and lower mold are lowered, and the rod-shaped material in the cavity of the lower mold is pushed up by the fixed die, and the rod-shaped material is moved into the cavity of the upper mold. The forging material is made to flow and the forging material is upset-formed while the outer periphery of the rod-shaped material is restrained by the inner periphery of the cavity of the upper die.

This allows the rod-shaped material to be formed without eccentricity, resulting in a forging material with a uniform wall thickness, and since upsetting is performed with the outer periphery constrained, a forging material with a high degree of circularity can be obtained. It becomes like this.

Furthermore, since a concave portion can be formed in the workpiece by the protrusion provided at the upper end of the fixed punch, molding that was conventionally performed in two steps can now be performed in one step.

〔Example〕

An embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. 1 to 3.

In the figure, 1 is an upper mold, and 2 is a lower mold. The upper mold 1 is attached to a slide of a forging press (not shown), and is moved up and down together with the slide.

A cavity 1a having an inner diameter equal to the outer diameter of the forging material 3 to be formed is formed on the lower surface of the upper die 1, and a slide knockout 4 is provided at the center of the cavity 1a to push out the forging material 3 from within the cavity 1a after forming. is provided to be able to move up and down.

The lower die 2 is formed with a cavity 2a having an inner diameter approximately equal to the outer diameter of the rod-shaped material 3' for forming the forging material 3, and the entire body is elastically supported by the guidance 5. A fixed lower punch 7 is provided which is fixed to the bed 6 side and cannot move up and down.

Next, to explain the method of forming the forging material 3 from the rod-shaped material 3' using the upper and lower molds 1 and 2, first, the rod-shaped material 3' to be formed is placed inside the cavity 2a of the lower mold 2 as shown in FIG. The upper mold 1 is then lowered in this state, and the rod-shaped material 3' is pressurized between the upper mold 1 and the fixed lower punch 7.

As a result, molding starts from the upper part of the rod-shaped material 3' whose periphery is not constrained, and when the rod-shaped material 3' has flowed to some extent, the upper mold 1 is pressed against the lower mold 2, and the cavity 1a in the upper mold 1 is closed. be done.

Thereafter, as the upper mold 1 further descends, the upper mold 1 and the lower mold 2 are lowered in a closed state due to the action of the die cushion 5, whereby the material 3' in the cavity 2a of the lower mold 2 is lowered.
is flowed into the cavity la in the upper die 1 in the same manner as the fixed lower punch 7 pushes it up.

When the slide reaches the bottom dead center, the upsetting of the forging material 3 whose periphery is restrained by the inner periphery of the cavity 1a of the upper die 1 is completed.

Thereafter, the upper mold 1 is raised together with the slide, and the completely formed forging material 3 is ejected from the cavity la by the slide knockout 4 provided at the center of the cavity la.

〔Effect of the invention〕

As described in detail above, this invention performs forming with the rod-shaped material restrained at the center of the cavity of the lower die, so that the rod-shaped material does not shift from the center of the cavity. There is no variation in the thickness or shape of the material.

As a result, even when the forging material is formed into a product, the inner diameter and outer diameter of the product will not be eccentric, and a highly accurate product can be obtained.

In addition, the forging material is formed while the outer periphery is constrained in the cavity of the upper mold that is closed between the upper mold and the lower mold, making it possible to obtain a forging material with good roundness. Therefore, when forged into a product, a good product with no missing parts or the like can be obtained.

In addition, in the past, as shown in Figure 7 (a), three
In contrast to the method used to obtain a forging material through several steps, this invention method provides a protrusion at the upper end of the fixed lower punch, making it possible to obtain a forging material in two steps, thus shortening the process. will be able to achieve this.

[Brief explanation of drawings]

Figures 1 to 3 are process diagrams showing an embodiment of the manufacturing method of the present invention, Figures 4 to 6 are explanatory diagrams showing a conventional manufacturing method, and Figures 7 (a) and (b) are process diagrams showing an embodiment of the manufacturing method of the present invention. FIG. 2 is an explanatory diagram showing a comparison of the number of steps between the method of the present invention and the method of the present invention. 1 is an upper mold, 1a is a cavity, 2 is a lower mold, 2a is a cavity, 3 is a forging material, 3' is a rod-shaped material, 5 is a die cushion, 7 is a fixed lower punch, and 7a is a protrusion. Applicant Komatsu Manufacturing Co., Ltd. Representative Patent Attorney Masaaki Yonehara

Claims (1)

[Claims] The lower part of the rod-shaped material 3' is inserted into the cavity 2a of the lower mold 2, which is elastically supported by the die cushion 5, and the centers of the cavity 2a and the material 3' are aligned, and in this state, the upper mold 1 is lowered and the upper Molding is first started from the upper side of the rod-shaped material 3' between the mold 1 and the fixed lower punch 7 having a protrusion 7a on the upper part provided in the cavity 2a of the lower mold 2, and then the upper mold 1 is moved to the lower mold 2. By lowering the upper mold 1 and the lower mold 2 while closing the cavity 1a of the upper mold 1 by pressing against them, the rod-shaped material 3' in the cavity 2a of the lower mold 2 is pushed up with the fixed lower punch 7. Using the same action, the rod-shaped material 3' is transferred to the upper mold 1.
into the cavity 1a of the upper mold 1.
(a) A method for producing a forging material, which comprises upsetting a forging material 3 while restraining the outer periphery of a rod-shaped material 3' at its inner periphery.