JPS59107002A - Production of sintered parts - Google Patents

Abstract

PURPOSE:To obtain >=2 recompressed or sintered forged bodies from single green compact molding or blank material before forging by shearing and separating the green compact molding or blank material before forging to be made into >=2 parts by means of a plunger die for recompression or sintering and forging die and subjecting the same to recompression or sintering and forging. CONSTITUTION:A blank material 1 before forging which is molded integrally with parts 2, 3 to be made into outer and inner rings is produced into the state of having about 10-20% void volume and insufficient mechanical strength by compression molding and sintering raw material powder in the stage of producing, for example, an outer ring and an inner ring for a bearing. The material 1 is set, as shown in the figure, in a sintering and forging die 4 wherein the punches 6B, 7A of upper and lower punches 6A and 6B, 7A and 7B for outer and inner races having different descending strokes are held afloat by means of springs 2, 10. When the punches 6A, 7A are lowered, the part 2 which is held by the punch pair 6 to the part 3 held by the punch pair 7 is depressed in this state and is sheared to two parts. The parts 2, 3 sheared and separated by the descent of the punches 6A, 7A are further directly pressed, and are then sintered and forged.

Description

[Detailed description of the invention] This invention relates to a method for manufacturing sintered parts.

As is well known, sintered parts can omit post-processing such as cutting, so the manufacturing process can be simplified, and by changing the ingredients and blending amount of raw material powder, materials with various ingredients can be obtained. Because of its advantages such as high strength, it is used in various fields, and recently its use has been expanded to include parts that take advantage of porosity, as well as parts called high-strength parts.

By the way, as a method for manufacturing high-strength sintered parts, a powder compact obtained by compression molding raw material powder is sintered, and the resulting preform (#Il pre-forming material heating and A method is known in which a sintered body is produced by sintering and forging which is performed simultaneously with pressurization, and the sintered body is subjected to post-treatment such as heat treatment or surface hardening treatment to produce a product.However, conventionally,
For each part to be obtained, a compacted powder body is made by compression molding using an individual pressing mold, and each compacted compact is sintered,
Sintered parts are manufactured through processing such as sinter forging, and as the number of types of parts to be manufactured increases, the number of pressing dies and forging dies for compression molding must also increase. Since there is a limit to the number of presses per unit time for forming presses and sinter-forging presses, if a large number of parts are to be manufactured, the number of presses must be increased. In any case, with conventional manufacturing methods, there is a limit to productivity, and there is no way to expand the equipment to further increase production, and considering the current situation where the range of use of sintered parts is expanding, This invention was made in response to the above-mentioned demands, and it is desirable to have a highly productive manufacturing method.
The purpose is to provide a method for manufacturing sintered parts with high productivity that can produce recompressed bodies or sintered bodies of 1x or higher. The compacted compact or forged material that has been molded is sheared into quarters using a recompression die or sintered forging die, and the sheared and separated sections are then recompressed or sintered. It is in Sada, who is made by Yusakuzo.

Examples of the method of this invention will be described below.

1 to 3 are schematic diagrams for explaining an example of manufacturing an outer ring (outer race) and an inner ring (inner race) for a bearing by the method of the present invention,
First, the forged material (hereinafter referred to as preform) 1 will be explained. As shown in Figures 1 and 4, the preform 1 has a part 2 that will become the outer ring and a part 3 that will become the inner ring that are integrally formed. This preform 1
is manufactured by compressing raw material powder into the shape shown in FIGS. 1 and 4(A) and sintering it. Therefore, the preform 1 has a porosity of 10 to 20% relative to the total volume, and its mechanical strength is also insufficient. The preform 1 obtained as described above is set in a sintering forging mold 4 as shown in FIG.

The sintering forging die 4 includes a die 5 having an inner diameter that is approximately the same as the outer diameter of the preform 1, and upper and lower bunches 6A for the outer ring.

6B, upper and lower punches 7A, 7B for the inner ring, and core rod 8, and upper and lower punches 6A for the outer ring.
, 6B have a cylindrical shape with the same outer and inner diameters as the outer ring to be obtained, and similarly, upper and lower inner ring punches 7A and 78G have the outer and inner diameters of the inner ring to be obtained. The core rod 8 has a cylindrical shape with the same outer diameter and inner diameter, and the core rod 8 is inserted into the preform 1, and the outer diameter is set to be approximately the same as the inner diameter of the preform 1. And upper bunch 6A for outer ring
is attached to the lower surface of the upper punch spacer 9, while the outer ring lower punch 6B is held at a predetermined height on the lower punch spacer 11 by a spring 10. Further, the upper punch 7A for the inner ring is held at a predetermined distance from the lower surface of the soil bunch spacer 9 via the spring 12, whereas the lower punch 7B for the inner ring is held by the lower punch spacer 1.
It is installed on top of 1. In addition, upper and lower punches 6 for the outer ring
Total length including lengths A and 6B and upper and lower punches for inner ring 7A
, 7B is set to be the same, and is the difference in length between the upper bunch 6A for the outer ring and the upper bunch 7A for the inner ring, and the length between the lower punch 6B for the outer ring and the lower punch 7B for the inner ring. The difference in height is set to be greater than the axial length of the outer ring and the inner ring, respectively.

FIG. 1 shows the baked F! preform 1 constructed as described above.
i Set in forging die 4, and each upper bunch 6A.

7A is shown slightly lowered, and the preform 1 has the core rod 8 inserted into its center.
It is held in the radial direction by the core rod 8 and the die 5. After the upper punches 6A and 7A come into contact with the upper surface of the preform 1, when they further descend, the upper bunch 6A for the outer ring is fixed to the upper punch spacer 9, and the lower punch 6 for the outer ring
B is in a so-called 70-ting state due to the spring 10, whereas the inner ring upper punch 7A is
Since the lower punch 7B for the inner ring is fixed to the lower punch spacer 11 while being in a so-called 70-ting state with respect to the upper punch spacer 9, as shown in FIG. The part 2 which is to become the outer ring is pushed up against the part 3 which is to become the inner ring held by the upper and lower punches 6A and 6B for the outer ring. As a result, the preform 1 is easily sheared into two parts due to its still high porosity.

As shown in FIG. 3, when the lower punch 6B for the outer ring is in contact with the lower punch spacer 11 and the upper bunch 7A for the inner ring is in contact with the upper punch spacer 1o, each portion 2.3 is completely Sheared, therefore, by further pushing down each upper bunch 6A, 7A in this state, a pressing force is directly applied to each sheared and separated portion 2.3, so that each portion 2.3 is sintered and forged. FIG. 4(B) shows each sintered body obtained. Each of these sintered bodies is processed and
It is processed and made into a final product.

Therefore, according to the above-mentioned method, two sintered bodies can be obtained from a single preform 1, which doubles the productivity, and also requires a slight reduction in the IP manufacturing of compression molding molds and sintering forging molds. However, this will not result in an increase in the number of press machines.

In addition, although the above embodiment has been explained by taking the case of manufacturing an outer ring and an inner ring for a bearing as an example, the present invention can also be applied to the case of manufacturing other sintered parts such as connecting rods and caps for engines. be able to. Further, in this invention, the present invention is not limited to the case where two parts are obtained from the preform of the first part, but it is also possible to shear and separate a single preform into three or more parts to obtain three or more parts. Furthermore, the present invention can be applied not only to the case of performing sinter forging but also to the case of obtaining a product by recompressing a powder compact.

As is clear from the above description, the method of the present invention can be used to form a powder compact or a #! This is a method of shearing and separating the parts that are to become each part using a recompression die or sinter forging die, and then recompressing or sintering the separated parts. It is possible to obtain two or more sintered parts from a powder compact or a raw material before forging, and therefore productivity can be greatly improved without the need to add special equipment such as a press machine, and the practical field has been improved. I can do a lot of work.

[Brief explanation of drawings]

1 to 3 are schematic diagrams showing the sintering and forging process according to an embodiment of the present invention, FIG. 4(A) is a perspective view showing a preform, and FIG. FIG. 2 is a perspective view showing a sintered body. 1... Preform, 2... Part that should become the outer ring, 3... Part that should become the inner ring, 4... Sintering forging mold, 6A... Upper punch for outer ring, 6B... Outer ring Lower punch for use, 7A... Upper punch for inner ring, 7B... Lower punch for inner ring, 10.12... Spring. Representative Toyota Motor Corporation 1ill Vehicle Co., Ltd. Patent Attorney Yutaka 1) Hisashi Take (and 1 other person) Figure 1 Figure 2 Figure 3 Figure 4 (A) (8)

Claims (1)

[Claims] The recompression die is equipped with at least two punches with different downward strokes, and the compacted product or fR pre-formed material, in which at least two parts have been integrally molded, is pressed into each part by the recompression die. A method for manufacturing a sintered part, characterized in that 1q of two or more recompressed products are simultaneously produced by shearing and separating each part and compressing each sheared and separated part.