JPH0293172A - Sintered alloy sealing ring for floating seal and manufacture thereof - Google Patents

Abstract

PURPOSE:To secure the high dimension precision and permit the machining other than the grinding work for a sliding part by positioning the compressed powder molding material which can be easily generate strain by an inner cylinder and restrain the compression to the inside, in the sintering of a sealing ring. CONSTITUTION:A hollow disc-shaped sliding part 1 made of abrasion-resistive sintered alloy, an annular trunk part 2 and a skirt part 3 which are prepared by the mixing of the iron material powder and press-molding, and a tubular inner cylinder 4 prepared from the low carbon steel rolled member are combined and liquid-phase-sintered, and then said sliding part 1, trunk part 2, skirt part 3, and the inner cylinder 4 are perfectly fused. In this sintering, since the compressed powder molding material which can easily generate strain is positioned by using the inner cylinder and the contraction to the inside is restrained, the combination of the compressed powder molding material and positioning are facilitated, and the high dimension precision can be obtained, and the need of machining other than grinding work for the sliding part is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a seal ring for a floating seal used in construction machinery and the like, and particularly to a seal ring using a sintered alloy in its sliding portion and a method for manufacturing the same.

[Prior Art] A floating seal used in construction machinery, etc. has two seal rings, as shown in Figure 3. a, 7b are supported by two O-rings 8a, 8b, and the seal ring ? Push a and 7b in the axial direction, and place them in close contact with each other with one on the rotating side and the other on the fixed side.
The sliding surfaces of the seal rings 7a and 7b, the rotating body 9a,
Fixed body 9b and seal ring? a.

With two O-rings 8a and 8b that are in close contact with 7b,
The seal rings 7a and 7b have the function of preventing the intrusion of dirt, muddy water, etc. from the outside and the leakage of lubricating oil from the inside. Conventionally, the seal rings 7a and 7b often have sufficient wear resistance against dirt and sand. High chromium white cast iron is used, and as shown in Figure 4, another technique is a seal in which a sliding part 11 made of compression molded powder is fused to a base 10 of carbon steel by liquid phase sintering. A ring is known from Japanese Patent Application Laid-Open No. 63-65002.

[Problems to be Solved by the Invention] However, since the high chromium white cast iron is a highly hard material, it is difficult to process parts other than the sliding parts, such as the seal ring shown in FIG. a, 7t) requires a large amount of time to finish the contact surfaces with the O-rings 8a and 8b, the material is brittle and must be handled with care, and the material is expensive, so manufacturing costs are included, including processing costs. There was a problem that the cost was high.

Furthermore, in the technique disclosed in Japanese Patent Application Laid-Open No. 63-65002, it is difficult to position the sliding part 11 made of powder by compression molding and the base 10 made of carbon steel. When the density of
Therefore, there were problems such as increased distortion of the carbon steel base IO unless a straightening jig was used.

The present invention has focused on the above-mentioned conventional problems, and an object of the present invention is to provide a seal ring that has a sliding part with excellent wear resistance, good dimensional accuracy, and can reduce manufacturing costs, and a method for manufacturing the same. shall be.

[Means for Solving the Problems] In order to achieve the above object, a sintered metal seal ring of a floating seal according to the present invention has a high resistance to resistance in a floating seal consisting of two seal rings and two O-rings. A hollow disc-shaped sliding part made of an abrasive sintered alloy, an annular body and skirt made of an iron-based sintered body fused to the sliding part, and an outer peripheral part of the sliding part, A hollow disc-shaped sliding part made of a wear-resistant sintered alloy, or a hollow disc-shaped sliding part that is inserted into the inner diameter of the body part and the hem part and fused to each of the above-mentioned sintered bodies. an annular body fused to the sliding part and made of an iron-based sintered body; a tubular part inserted through the respective inner diameters of the sliding part and the body, and a flange part provided at one end of the tubular part for external use; The seal ring is made up of an inner cylinder fused to each of the above sintered bodies, and the manufacturing method for the seal ring is as follows: After compression molding, when combining and sintering, insert an inner cylinder into the inner diameter of the sliding part, body part, and hem part, or insert an inner cylinder having a flange part at one end into the inner diameter of the sliding part and body part. While positioning each compacted body, restraining each compacted body from shrinking inward, each compacted body and the inner cylinder were fused together by liquid phase sintering.

[Function] According to the above configuration, the powder compacts that are less susceptible to distortion during sintering are positioned by the inner cylinder and restrained from shrinking inward, making it easy to combine and position the compacts. High dimensional accuracy can be obtained, and processing other than grinding of the sliding portion can be eliminated.

[Example] Examples of the sintered metal seal ring of the floating seal and the manufacturing method thereof according to the present invention will be described below.
This will be explained in detail with reference to the drawings.

FIG. 1 is an embodiment according to claim (1), and C: 3
．． 0%, Cr: 15.3'%, Mo: -2.75%, V: 0.78%, Ni:
1.60%.

P: 0.25%, the balance is Fe mixed raw material powder, and press-molded with a surface pressure of 6 ton/cTn2 to form a hollow disk-shaped sliding part 1 with an inner diameter of 100 mm, and C: 2.5%, C.
Raw material powders consisting of r: 1%, Mo: 0.5%, P: 0.5%, and the remainder Fe were mixed, and the surface pressure was 6 ton/cT.
An annular body part 2 and a hem part 3 with an inner diameter of 100 mm press-formed by n2, and a tubular inner cylinder 4 with an outer diameter of 98 mm produced by TIG welding after bending low carbon control rolled material, The seal ring is liquid-phase sintered by heating at 1160°C to 1190°C for 2 hours, and has a sliding part 1, a body part 2, and a hem part 3.
, the inner cylinder 4 is completely fused.

FIG. 2 shows an embodiment according to claim (2), in which the sliding part 1
The raw material powder composition, shape and molding conditions of
). Further, the composition and molding conditions of the body part 5 are the same as those of the body part 2 of claim (1), and the shape is a conical shape having the same taper and the same dimensions as the body part 2. The inner tube 6 is machined from 543C material and has a flange 6a at one end of the tubular portion.

The body part 5 compression-molded into the inner cylinder 6 and the sliding part 1 were fitted and liquid-phase sintered by heating at 1160°C to 1180°C for 2 hours. The cylinder 6 is completely fused.

In addition, the sliding part 1, body part 2 or 5, and skirt part; Since shrinkage of about 6 to 8% occurs, the outer diameter of the inner cylinder 4 or 6 is 9% of the inner diameter of the powder compact.
It must have a size of 4% or more and be made of a material with a higher melting point than the compact.

In this embodiment according to the above configuration, FIG.
The roundness of each of the 20 seal rings shown in FIG. 2 was compared with that of JP-A-63-65002 shown in FIG.
The former is 0.4 mm or less, the latter is 1.5 mm or less,
It can be seen that the dimensional accuracy was significantly improved by applying the present invention.

[Effects of the Invention] As explained above, according to the present invention, the compacted compacts, which are less susceptible to distortion during sintering, are positioned using the inner cylinder and restrained from shrinking inward, so that each compacted compact is It becomes easy to combine and position the molded bodies, high dimensional accuracy can be obtained, and machining other than grinding of the sliding part can be made unnecessary.

In addition, since the other parts except the sliding part are made of inexpensive materials, the manufacturing cost can be significantly reduced as well as the parts other than the sliding part can be left unprocessed.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a seal ring of a floating seal according to an embodiment, and FIG. 1 shows claims (1) and 2.
The figure is according to claim (2), FIG. 3 is a partial sectional view of a floating seal and its surroundings according to the conventional technology, and FIG.
The figure is a sectional view of a seal ring according to Japanese Patent Application Laid-Open No. 63-65002. 1... Sliding part 2.5... Body part 3... Hem part 4.6... Inner cylinder 6a... Flange part Patent applicant: Komatsu Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A floating seal consisting of two seal rings and two O-rings includes a hollow disc-shaped sliding part 1 made of wear-resistant sintered alloy, and a metal part fused to the sliding part 1, The annular body part 2 and hem part 3 made of a sintered body of the system, and the outer peripheral part are inserted into the inner diameters of the sliding part 1, body part 2, and hem part 3, and fused to each of the sintered bodies. A floating seal made of a sintered metal seal ring, characterized in that it is constructed of an inner cylinder 4 with a cylindrical shape. (2) The seal ring according to claim (1) includes a hollow disc-shaped sliding portion 1 made of a wear-resistant sintered alloy, and a seal ring fused to the sliding portion 1 and made of an iron-based sintered body. An annular body 5,
A tubular part is inserted into the inner diameter of each of the sliding part 1 and the body part 5, and the outer periphery of the tubular part and the flange part 6a provided at one end are constituted by an inner cylinder 6 fused to each of the sintered bodies. A floating seal made of a sintered metal seal ring. (3) After compression molding the raw material powders for the sliding part 1, body part 2, and hem part 3 or the sliding part 1 and body part 5, when combined and sintered,
Inserting the inner cylinder 4 into the inner diameter of the sliding part 1, body part 2, and hem part 3,
Alternatively, an inner cylinder 6 is inserted into the inner diameter of the sliding part 1 and the body part 5 to position each compacted body and to restrain each compacted body from shrinking inward. and a claim characterized in that the inner cylinder is fused by liquid phase sintering (
1) The method for manufacturing a sintered metal seal ring described in (2).