JPS6099533A - Method of manufacturing spherical piece - Google Patents

Abstract

PURPOSE:To accurately and efficiently process a hard brittle material to a spherical piece of a desired dimensions, by making a spherical workpiece consisting of a spherical portion and a projecting portion coaxially extending therefrom, and by grinding the spherical portion and thereafter grinding off projecting portion from the spherical portion. CONSTITUTION:A ceramic powder or the like is filled in a die to press-mold a spherical workpiece 4 consisting of a spherical portion 5 and a columnar projecting portion 6 whose axis extends through the center of the spherical portion 5. The spherical workpiece 4 is then baked. The spherical portion 5 is ground by a forming grindstone 9 while the projecting portion 6 is held by a chuck 7. After that, the projecting portion 6 is ground off by a forming grindstone 13 while the spherical portion 5 is held by a chuck 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a spherical body made of a hard and brittle member such as ceramics.

[Technical background of the invention and its problems]

Conventionally, ceramic spheres used in ball bearings and the like are, for example, HIP (Hot l5ostatic).
It is obtained by press-forming into a sphere using a hot isostatic press or the like, and then firing the press-formed sphere at a normal temperature. However, the dimensions of the spheres immediately after firing vary depending on the pressing conditions and firing conditions, so the dimensions immediately after firing are usually 1.2 to 1.2 to the final dimensions.
It is fired to increase its size by 1 to 3 times, and then finished by lapping to reach the final size.

This lapping process involves processing a plurality of ceramic spheres with varying dimensions, so the processing efficiency is extremely low and the processing time is long. Moreover, the lapping machine has the disadvantage that it is easily worn out and it is difficult to obtain the desired machining accuracy.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and relates to a spherical body manufacturing method that can process a hard and brittle member such as ceramics into a spherical body of a desired size with high precision and high efficiency.

[Summary of the invention]

After forming a spherical body consisting of a spherical part and a protrusion coaxially protruding from the spherical part, gripping at least the protrusion of the spherical body with a chuck and grinding the spherical part that is not directly gripped, Furthermore, the ground spherical part is gripped by a chuck, and the unground part including the protrusion part is ground.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

First, the hollow part (3) formed by the soil and lower molds (1) and (2) as shown in Fig. 1 is filled with ceramic powder, and the ceramic powder is filled as shown in Fig. 2 (a) and (b). A spherical body (4) like this is press-molded. This spherical body (4) consists of a spherical part (5) that is a perfect sphere, and a cylindrical protrusion (6) that protrudes so that its axis passes through the center of the spherical part (5). Next, the press-molded spherical body (4) is fired at a predetermined temperature and time. This spherical body (4) is then chucked (7).
), grip the chuck (7) and the protrusion (6) so that they are coaxial (see Fig. 3). This chuck (7
) The part of the spherical body (4) that is in direct contact with the protrusion (6
) and the surface of the spherical part (5) around this protrusion (6). Next, the chuck (7) is rotated about its axis (8) as the rotation axis, and the spherical part (5) surface 1 which is not in contact with the chuck (7) is rotated, and the general grindstone (9) is rotated about its axis αQ. Rotate it around the axis and cut in the direction of the arrow until it reaches the final dimension position shown by the dotted line in Figure 3. At this time, the axis (8).

(10 are set to be parallel to each other. Also, in the aspect that becomes the grinding surface of this full-form grindstone (9).

Diamond abrasive grains are deposited with copper as a bonding agent.

- At Siya) L), remove the spherical body (4) that has been ground to the final size with the general grindstone (9) from the chuck (7),
This time, the spherical part (5) was ground into the chuck 0υ.

Grip the chuck αυ and the protrusion (6) so that they are coaxial. Next, the chuck (1υ) is rotated with its axis (12) as the rotational axis, and the partial surface that has not been ground by the general grindstone (9) is rotated with the general grindstone 03) with its axis αX as the rotation axis, Cut in the direction of arrow B to the final dimension position shown by the dotted line in Figure 4.

Along with this, the protrusion (6) is ground away, and finally a sphere a having the desired outer diameter can be obtained.

In this way, in this embodiment, the final finishing of the spherical body (4) is carried out by grinding with a full-form grindstone, so that the final finishing of the spherical body (4) is done by grinding with a full-form grindstone. Processing can be performed with high efficiency and precision. Therefore, the yield is improved and the manufacturing cost is also reduced.

In the above embodiments, the purpose is to manufacture a true sphere, but the present invention is not limited to this, and the present invention can be applied to any manufacture of spherical bodies such as oval or elliptical spheres. However, it is necessary to set the axes of these oval and elliptical spheres and the projections coaxially. Furthermore, the protrusion is not limited to a cylindrical shape, but may be a prismatic shape. Yet again.

Although the above embodiments describe processing of ceramic members, the present invention is not limited to ceramic members and can be applied to all hard and brittle members. Of course, the scope of application can also be extended to general metal finishing. Therefore, good.

〔Effect of the invention〕

According to the present invention, finishing processing of one spherical body can be performed with high efficiency and high precision. This 1 in 7 spherical body can significantly reduce the manufacturing cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a mold used for press molding in an embodiment of the present invention, FIGS. 2(a) and (b) are a front view and a plan view of a press-molded spherical body, respectively, and FIG. 3 and FIG. 4 are diagrams showing processing using a full-form grindstone according to an embodiment of the present invention. (4): Spherical body (5) Two spherical parts (spherical part) (6): Protrusion (7), <Ill: Chuck agent Patent attorney Norikinsai Tasuku (1 person) Figure 1 3 3 Figure 2 (6) (b) Figure 4

Claims (1)

[Claims] A molding process of forming a spherical body consisting of a spherical part and a protrusion coaxially protruding from the spherical part, the above-mentioned evacuation process, and the gripping of the spherical body surface ground by the above-mentioned first grinding process with a chuck. and a second grinding step of grinding the surface of the spherical object that has not been ground in the first grinding step and removing the projection.