JPH0235108Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to the structure of a gasket (synonymous with packing) that is interposed on the joint surface of the pipe end in a pipe joint, etc., and the internal thread of the joint body is In addition to preventing the gasket fitted to the inner end from moving,
The technical feature is that the hard ring on the inner peripheral surface prevents the effective area of the pipe from being narrowed due to compression of the gasket.

[Conventional technology and its problems]

Conventional gaskets of this type were made only of elastic materials such as rubber, so they were interposed between, for example, the inner end surface of a pipe joint and the end surface of a connecting pipe that was butted against the surface, and were clamped together. In some cases, the gasket may be compressed and deformed in the axial direction, causing its inner peripheral surface to bulge toward the flow path, narrowing the effective area of the pipe, or causing the rubber to lose its elasticity due to long-term tightening. ,
This could easily lead to fluid leakage. As a countermeasure to these problems, a technique is known in which a hard ring is attached to the inner or outer surface of a gasket that has a certain amount of compression (for example, Utility Model Application Publication No. 53-59713, etc.), but all of these techniques have multiple structures. In addition, there were problems in that the gasket, which is installed in advance at the back end of the joint before pipe connection, would fall down due to vibrations during connection, become misaligned from the joint surface, or fall off. It was hot.

[Means for solving problems]

Therefore, the present invention mainly uses a protruding strip on the outside of the gasket main body made of an annular elastic material having a certain amount of depression at the pipe end joint where the external thread of the connecting pipe is screwed into the internal thread of the joint body. In addition, all of the above-mentioned problems have been solved by providing a hard ring on the inner circumferential surface of the gasket main body, the inner circumference of which is at least larger than the inner diameter of the conduit.

[Effect]

In the gasket of the present invention, the hard ring prevents the main body of the gasket from expanding toward the conduit when it is clamped, and at the same time suppresses the tightening of the main body of the gasket beyond its elastic limit.

Furthermore, the protrusions on the outer periphery of the main body of the gasket are engaged with the inner wall or internally threaded recess on the side of the joint body, thereby preventing the gasket from moving or falling off.

〔Example〕

Hereinafter, the configuration of the gasket of the present invention will be described in more detail according to an embodiment in which the pipe ends are connected to each other by a socket. 1 is an annular gasket main body made of a suitable elastic material such as rubber, and has a thin protrusion at the center of its outer periphery that can be elastically engaged with the inner wall or threaded part of the socket A. In the concave groove 1' extending through the inner circumferential surface of the gasket main body 1,
A hard ring 3 made of metal and having an inner circumference slightly larger than the inner diameter of the conduit and having a circular cross section, for example, is provided around the pipe.

The main body 1 of the gasket has an appropriate wall thickness that shrinks a certain amount when pressed against the end faces of both pipes B and C connected by the socket A, and is compressed and deformed when tightened. Because of its plasticity, it penetrates equally into both sides of the hard ring 3 and wraps the ring 3 in the center of the inner periphery of the gasket main body, so even if excessive clamping force is applied to the gasket main body, it will not exceed the elastic limit. This can prevent serious compression.

Further, the protrusions 2 may be scattered at appropriate intervals on the outside of the gasket main body 1.

In addition, for the hard ring 3, materials other than metal, such as hard plastic or ceramic, can be freely used, and the cross-sectional shape is not limited to circular, but may also be rectangular. Even if this book is used, the same effects as those described below can be obtained.

The proposed gasket is not limited to the above-mentioned socket joints, but can be applied to any type of joint, such as those that have a threaded part at the end of the connecting pipe on one side of the joint body, pipe joints using cap nuts, and union joints. It is possible.

[Effect of idea]

The proposed gasket according to the above structure is designed such that the thin protrusion on the outer periphery of the main body elastically engages with the inner wall of the joint main body or the screw groove to keep the gasket main body in place, especially for connecting pipes downward. Even if the gasket is closed, the center of the gasket should not shift or fall off, and the hard ring prevents the inner circumferential surface of the main body of the gasket from expanding toward the flow path when tightening. This is to reliably prevent water leakage and constriction of the effective area of the pipe.

Further, the present invention brings about remarkable effects such as the presence of the hard ring, which prevents excessive tightening pressure from being applied to the main body, and allows the gasket function to be maintained over a long period of time.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of the center of the proposed gasket, Figure 2 is a longitudinal sectional view of the center showing the state before tightening in an example of its use, with the lower half omitted, and Figure 3 is a longitudinal sectional view of the center after tightening. FIG. 7 is a vertical cross-sectional view of the central portion showing the later state with the lower half thereof omitted. In addition, in the figure 1... annular main body, 2... protrusion, 3...
hard ring.

Claims (1)

[Scope of utility model registration request] A protrusion 2 is provided on the outside of the gasket main body 1 made of an elastic material having a certain amount of depression, and a hard ring 3 whose inner circumference is at least larger than the inner diameter of the pipe is provided on the inner peripheral surface of the gasket main body 1. A gasket characterized by: