JPS61133303A - Production of mechanical element - Google Patents

Abstract

PURPOSE:To produce easily sliding members which slide or rotate relatively with a spherical convex face and spherical concave face by coating an antisticking agent on the surface of the member having the spherical convex face and molding and sintering a metallic green compact having such member as a core. CONSTITUTION:An inner piece having the spherical convex part 10 at the top end of a shaft member 11 is manufactured by machining. The part 10 is dipped into a suspension of graphite powder or solid antisticking agent such as MoS2 or BN and is pulled up and dried to form a housing member 20 and the antisticking agent on the surface. The member is then supported and loaded into the cavity of a die 30 by means of a core 60 and an inner lower punch 50 and thereafter raw material powder for forming the housing part is packed into the cavity and is compressed between an upper punch 70 and an outer lower punch 40 to form the housing member 20. The green compact is sintered at 1,100 deg.C by which the sintered housing member is manufactured. The member 20 functions as a spherical joint without sticking to the inner member by the presence of the antisticking agent. The excellent members which slide and rotate with each other are thus easily produced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a mechanical element consisting of a pair of members that slide or rotate relative to each other.

Conventionally, when manufacturing machine elements in which a member with a spherical convex surface and a member with a spherical concave surface are slid together, such as the self-aligning bearing shown in Figure 1 and the spherical journal shown in Figure 2, both parts are cast in one casting machine. Many methods are used, such as a method in which the housing members are manufactured separately by processing and then plastically deformed to wrap the outer housing member, or a method in which a cut groove is provided in the housing member and the housing members are fitted together.

However, in these conventional methods, it is necessary to finish both parts separately with high precision and then combine them, which tends to complicate the processing process and increase the price.

The purpose of the present invention is to obtain a high-quality and inexpensive mechanical element by omitting the process of adjusting the dimensions of the spherical parts of both members and the assembly process from the conventional method. A layer of graphite or other anti-welding agent is provided on the surface of the housing member, which is embedded in metal powder that becomes the housing member, and then integrally molded and sintered.

Hereinafter, an embodiment in which the present invention is applied to manufacturing the machine element shown in FIG. 2 will be described in detail.

The inner piece 10 is a machined product made of 545C material, and has a spherical convex portion at the tip of the shaft portion 11. Then, this inner piece 10 is immersed in a suspension of fine graphite powder, then pulled up and dried to form a graphite coating on its surface to prevent welding to the housing member.

Next, this inner piece 10 is supported and loaded into the cavity of the die 30 as shown in FIG. The member raw material powder is filled and compressed between the upper bunch 70 and the outer lower bunch 40 to form the housing member 20.

In the above forming process, the core 60 and the inner lower punch 50 are
In addition to supporting the inner piece to the mushroom at a predetermined position, the core also serves as an extrusion bottle for compacted powder, and the inner lower punch is
φ functions as a core that forms an operating gap 12 between the shaft portion 11 of the inner piece and the housing.

The housing components are 5% copper and 1% graphite by weight.

and iron balance, with 1% zinc stearate added as a lubricant. The compacted powder density of the housing 20 is a
8L'cj.

When the green compact is extracted from the die, it expands by about 02 to 4% due to springback, creating a gap between it and the inner piece 10.

Next, this green compact was inserted into a sintering furnace at a temperature of 1100°C,
The housing member is sintered. At this time, due to the effects of the graphite coating and the gap between the two members, welding of the housing member and the inner member is prevented, and the function as a ball and socket joint is maintained. Next, the housing member is subjected to oil impregnation treatment to complete the required mechanical element.

As is clear from the above description, in the present invention, there is no need to separately manufacture and assemble both the inner and outer members as in the past, and the spherical concave surface of the housing member is formed to follow the spherical convex surface of the inner member. Because of this, the fitting precision is good, and therefore, a high quality and inexpensive mechanical element can be obtained.

In carrying out the present invention, the inner member 10 is not limited to a cut product, but may be a cast product, a sintered crystal, or any other material that can withstand sintering temperatures, and the material of the housing member may also be changed depending on the use of the machine element. can be selected as appropriate.

Various substances are used as anti-adhesive agents during sintering, but considering the lubricating effect during operation, boron nitride and binary molybdenum are suitable in addition to graphite.

[Brief explanation of drawings]

FIGS. 1 and 2 are drawings illustrating a self-aligning bearing unit and a globe journal as examples of mechanical elements to which the present invention applies, and FIG. 3 is a drawing illustrating the powder molding process of the one shown in FIG. 2. It is.

Claims (1)

[Claims] 1. In manufacturing a machine element consisting of two members that slide or rotate relative to each other, a step of coating the surface of the member having a spherical convex surface with an anti-welding agent, and incorporating this as a core. A manufacturing method comprising the steps of: forming a metal powder green compact, and sintering the green compact. 2. The manufacturing method according to claim 1, wherein the anti-welding agent is graphite, boron nitride, or molybdenum disulfide.