JPS5854215A - Spherical joint - Google Patents

Abstract

PURPOSE:To enable holding sealing ability over a long period in such a way that difference is offered to the radius for the curvature between the inner face of the spherical part which has been provided on the pipe and the upper face of a gasket which has been provided so that it can be brought in slidable contact. CONSTITUTION:When the inner face 4a of the spherical part 4 of a pipe 2 and the upper face 6a of a gasket 6 are originally made in the spherical shape with radius of the same curvature, the inner face 4a is abnormally worn resulting from the creation of the part of wire net which is protruded in the gasket all over the contiguous faces of the inner face 4a and of the upper face 4a. In consequence, it is constituted that the radius for the curvature of the inner face 4a and of the outer face 6a can be changed, originally they are brought in contact with one another just at one part, and in proportion as wear of graphite sheet in use is on the way, contiguous area of the inner face 4a and of the upper face 6a is gradually increased. Thus, with gradual wear on the upper face 6a, the face to which seal is worked is gradually moved inward, and favourable gas sealing ability is held for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a spherical joint used in an exhaust pipe connection of a front engine-front drive (hereinafter abbreviated as F) vehicle or diesel engine vehicle. .

Gaskets conventionally used for spherical joints are
The receiver has a sealing surface with the same radius of curvature as the side pipe end.
Compression molded metal fibers and graphite sheets are used. However, this type of spherical joint is
While the vehicle is running, the seal surface is subjected to uneven road surfaces and engine vibrations during acceleration and deceleration, and the seal surface undergoes a high frequency of shearing or compression movements, although the amount of displacement is not large. As a result, the goo-fighting sheet on the gasket surface of the spherical joint wears out, and the internal metal fibers locally come out to the surface. If operation continues under this condition, a phenomenon similar to 7retate/g wear will occur between the seal surface on the pipe side and the metal fibers on the gasket surface in the area where the metal fibers are exposed, and the seal surface on the pipe side will This causes abnormal wear in the shape of so-called lunar craters, resulting in significant casseal failure.

As a countermeasure, there are gaskets in which the metal fibers in the gasket are made thinner or the density of compression molding is increased. There is no effect because it comes.

SUMMARY OF THE INVENTION The object of the present invention has been made in view of the above-mentioned drawbacks, and as the gasket wears out, gas sealing is always performed at a new part little by little, thereby preventing gas leakage due to the wear of the gasket. The purpose is to extend the government ordinance and provide a nine-sphere joint.

In order to achieve such an object, the present invention is configured such that the radius of curvature of the inner surface of the spherical portion of the pipe and the upper surface of the gasket are different.

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 is a sectional view showing one embodiment of a spherical joint according to the present invention. The spherical joint 1 is used for the purpose of connecting two pipes 2.3 that move relative to each other and preventing gas flowing inside the pipes 2.3 from leaking to the outside of the pipes 2.3. The structure of the spherical joint 1 includes a spherical part 4 machined into a spherical surface at the lower end of the pipe 2, and a gasket 6 placed on the first 72-inch 5 and having an upper surface 6α formed on a spherical surface.
, a bolt 7 erected on the first seven flange 5, and a spring 9 interposed between the bolt 7 and a second bracket 8 disposed around the spherical portion 4. Be prepared,
Due to the elasticity of the core spring 90, the inner surface 4α of the spherical portion 4 of the pipe 20 is pressed against the upper surface 6a of the gasket 6 with a predetermined load, and the gas flowing inside the pipe 2.3 is
This prevents leakage to the outside from the contact surface between α and the upper surface 6a. The spring 9 also has the function of compensating for the amount of wear when the upper surface 6a of the gasket 6 is worn out due to the relative movement of the upper and lower pipes 2.3.

Next, the features of the embodiment will be explained. A conventional net made of metal fibers (hereinafter abbreviated as wire net),
When a gasket made by compression molding a graphite sheet is used, as the graphite sheet wears, a portion of the spherical upper surface of the gasket where a wire net comes out due to variations in molding occurs. Pipe 20 spherical part 4
If the inner surface 4α of the pipe 20 and the upper surface 6α of the gasket 6 are made into spherical shapes with the same radius of curvature from the beginning, such a wire net protruding portion will be formed on the entire contact surface between the inner surface 4a and the upper surface 6a, and especially if the spherical surface of the pipe 20 The inner surface 4a of the portion 4 will suffer abnormal wear. Therefore, in this embodiment, the radius of curvature of the inner surface 4a of the spherical portion 4 of the pipe 2 and the upper surface 6α of the gasket 6 are changed (in this embodiment, the radius of curvature of the upper surface 6α is made different from the radius of curvature of the inner surface 4α). ＼Set small), the structure is such that initially they contact only partially, and during use, as the wear of the Gra7ite sheet progresses, the contact area between the inner surface 4α and the upper surface 6α gradually increases. It is.

Therefore, in the structure of this embodiment, the gasket 6 is used to a certain extent, and when wear progresses, the second gasket 6 is used.
As shown in the above, the contact area between the upper surface 64 of the gasket 6 and the inner surface 4a of the spherical portion 40 of the pipe 2 is initially wider, and at the outer peripheral portion 6α' of the upper surface 6α of the gasket 6, the wire net is This is the spherical part 4 on the pipe 2 side.
The contact surface 4α' and the corresponding surface (outer periphery 6α', contact surface 44') have abnormal uneven wear, and although the surface pressure is shared, the gas seal function is lost. . However, due to the newly generated contact direction, the upper surface 6α of the tb gasket 6
Between the outer circumferential portion 6α〃 and the contact surface 4a1 of the spherical portion 4, there is no abnormal wear of the contact surface 4αl on the pipe 2 side, and therefore good gas sealing performance can be obtained. In this way, as the sealing surface of the gasket 6 and the upper surface 6α of the pawl gradually wear out, the surface that actually acts as a seal gradually moves inward, thus ensuring good gas sealing performance over a long period of time. Possible to retain.

Table 1 shows conventional type gaskets A, B, A', and B' after 15 days of driving on rough roads, and gaskets of the present invention c,
Gas leakage of spherical joint when c' is used it (
A comparison is shown when the internal pressure is 0.3KII/ai).

Table 1 As explained above, the spherical joint according to the present invention is configured so that the radius of curvature of the inner surface of the spherical part of the pipe and the upper surface of the gasket is different, so that it has the effect of having good gas sealing properties even after running for a long time. play.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the spherical joint according to the present invention, and FIG. 2 is an explanatory diagram of the operation of the spherical joint according to the present invention. ~1... Spherical joint, 2... Pipe, 4...
Spherical part, 4α...inner surface, 6...gasket, 6cL
...Top surface. Agent Tatsuyuki Unuma (and 2 others) Part I I'1 21-]

Claims (1)

[Claims] It is composed of a spherical part provided on the pipe and a gasket having a spherical upper surface formed to be in contact with the inner surface of the spherical part, and the core spherical part and the gasket move toward each other while receiving compressive stress. What is claimed is: 1. A spherical joint for performing the above-mentioned spherical joint, characterized in that the inner surface of the spherical portion and the upper surface of the gasket are configured to have different radii of curvature.