JPH0377744A - Method for forming flanged part - Google Patents

Abstract

PURPOSE:To smooth the flow of stock and to form a flanged part without using a large press by forming inclined surfaces to front surfaces on shoulder parts of upper and lower punches. CONSTITUTION:When an upper die 2 and the upper punch 4 in the upper die 2 are lowered to start forming the stock 1 after the stock 1 is blocked, the stock 1 flows into a cavity 2a forming an upper hub and a cavity 2b forming a flange. Thereafter, when the upper die 2 and the upper punch 4 in the upper die 2 are lowered further, the stock continues flowing without being detained by an inclined surface formed by the shoulder parts 4a, 4b of the upper and lower punches 4, 5 and a cavity 3a for forming the lower hub, too, is filled with the stock 1. After the compression of the stock 1 is completed the upper die 2 and the upper punch 4 are elevated, then, the lower punch 5 is elevated and a formed article is knocked out from within the lower die 3 to obtain a part having a flange on its external periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of forming a part having a flange around the periphery by warm closed forging.

[Conventional technology]

Conventionally, when molding a machine part A as shown in FIG. 4 which has a flange 1b around the periphery, a material e is first accommodated between an upper mold C and a lower mold d as shown in FIG. The mold C and the lower mold d are closed, then the punch f provided in the lower mold d is raised, and the material e is pressurized between the punch g provided in the upper mold C, as shown in Fig. 6 ( As shown in b), first the upper and lower hubs la,
lc is molded, and then the material e is made to flow into the cavity j in which the flange 1b is to be molded, thereby molding the flange 1b portion as shown in FIG. 6(c).

[Problem to be solved by the invention]

However, in the conventional molding method described above, the material e first flows into the cavity for molding the hub 1a, and after the cavity is filled with the material e, the material e flows into the cavity j for molding the flange 1b. As a result, there was a problem in that the material was rolled up in the part i shown in FIG. 6(c), and defects m such as rolled up occurred in the molded product as shown in FIG.

The present invention has been made in order to improve the above-mentioned problems, and it is an object of the present invention to provide a method for molding parts having flanges that does not cause defects such as curling.

[Means and operations for solving the problem] In order to achieve the above object, the present invention closes the material between the upper mold and the lower mold, and then closes the upper mold and the upper punch provided in the upper mold. The material is lowered and pressurized between the upper punch and the lower punch provided in the lower mold, and the upper hub and flange are first formed along the slope provided at the shoulder of the upper punch into the cavity. By flowing the material into the cavity that forms the lower hub along the slope provided on the shoulder of the lower punch and forming part A, the part A is free from entrainment defects. The present invention provides a method for molding a part having a flange that can be easily molded using a small press.

〔Example〕

An embodiment of the method of this invention will be described in detail with reference to the drawings.

First, a cylindrical material 1 is heated to a molding temperature of 800 to 900 DEG C., and then placed between an upper mold 2 and a lower mold 3, and the upper mold 2 and lower mold 3 are closed as shown in FIG.

An upper punch 4 and a lower punch 5 are provided in the upper mold 2 and the lower mold 3, respectively, and cavities 2a and 2b for forming the upper hub 1a are formed between the upper punch 4 and the upper mold 2, and the lower punch 5 Cavities 2b and 3a for forming the flange 1b and the lower hub 1c are provided between the upper die 3 and the lower die 3, respectively, and the shoulder portions 4a of the upper punch 4 and the lower punch 5.

5a, inclined surfaces 4c and 5c of 30'' to 60'' are formed around the entire circumference with respect to the tip surfaces 4b and 5b. Due to these inclined surfaces 4c and 5c, the diameters of the tip surfaces 4b and 5b of the upper punch 4 and lower punch 5 are D x 0.
It is 5 to 0.9.

After closing the material 1, the upper mold 2 and the upper punch 4 in the upper mold 2 are lowered to start molding the material 1. As shown in FIG. 2a and flange 1b into cavity 2b.

After that, when the upper die 2 and the upper punch 4 in the upper die 2 are further lowered, the shoulders 4a of the upper and lower punches 4 and 5 are removed.

Due to the inclined surfaces 4c and 5c formed in the lower hub molding cavity 3, the material continues to flow without stagnation.
It also fills into a.

When the pressurization of the material 1 is completed, the upper mold 2 and the upper punch 4 are raised, and then the lower punch 5 is raised to project the molded product from the inside of the lower mold 3, thereby forming a flange 1b on the outer periphery as shown in FIG. A part A having the following properties can now be obtained.

〔Effect of the invention〕

As described in detail above, this invention has sloped surfaces that slope from 30'' to 60'' with respect to the tip surfaces on the shoulders of the upper and lower punches, so that the material can be pressurized between the upper and lower punches. When the material is made to flow into the cavity where the flange 1b is to be formed, the material flows smoothly due to the above-mentioned inclined surface, making it possible to form parts with flanges without using a conventional large press. .

In addition, the material in the cavity for forming the upper hub does not accumulate due to the sloped surface of the punch, so it is possible to prevent defects such as entrainment.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIGS. 1 and 2 are forming process diagrams, and FIG. 3 is an enlarged view of the upper and lower punches.
FIG. 4 is a plan view of the mechanical part, FIG. 5 is a sectional view thereof, and FIGS. 6(A) to 6(C) are explanatory diagrams showing a conventional molding method. 1 is the material, 1a is the upper hub, 1b is the flange, 1c is the lower hub, 2 is the upper mold, 2a and 2b are the cavities, 3 is the lower mold, 3
a is the cavity, 4 is the upper punch, 4 is the shoulder, b is the tip surface, 5 is the lower punch, is the shoulder, b is the tip surface, A is the part.

Claims (2)

[Claims] (1) After closing the material 1 between the upper mold 2 and the lower mold 3, lowering the upper mold 2 and the upper punch 4 provided in the upper mold 2,
The material 1 is pressurized between the upper punch 4 and the lower punch 5 provided in the lower die 3, and the upper hub 1a and flange are first formed along the inclined surface 4c provided on the shoulder 4a of the upper punch 4. 1b
The material 1 is made to flow into the cavities 2a and 2b for forming the material, and then the inclined surface 5c provided on the shoulder portion 5a of the lower punch 5 is
Material 1 is placed in the cavity 3a along which the lower hub 1c is to be formed.
A method for molding a part having a flange, characterized in that part A is molded by flowing. (2) The forming method according to claim 1, wherein the angles of the inclined surfaces 4c and 5c of the upper punch 4 and the lower punch 5 are set at 30° to 60° with respect to the tip surfaces 4b and 5b.