JP2600789Y2 - Gasket for internal combustion engine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a gasket for an internal combustion engine.

[0002]

2. Description of the Related Art For example, when an exhaust pipe is connected to a cylinder of an internal combustion engine of a motorcycle, a gasket is interposed between connection ends thereof to prevent gas leakage. As shown in FIG. 5, a gasket used for a connection portion of such a pipe generally includes a sealing member 1 (in some cases, made of asbestos) made of stainless steel mesh and a circumferential groove having a U-shaped cross section at a peripheral edge of a thin metal plate ring 2. 3 are fitted in such a manner that the side walls 3a and 3b of the circumferential groove 3 are crimped from both sides.

As shown in FIG. 6, an exhaust port 6 of a cylinder head 5 has a slightly downward opening at a connecting portion of an exhaust pipe 4 of an internal combustion engine, and a gasket 8 is provided in a peripheral wall portion 7 of the exhaust port 6. After fitting, the end of the exhaust pipe 4 is inserted and fastened with the nut 9.
However, since the gasket 8 is opened downward, the gasket 8 tends to fall off before the gasket 8 is set in the exhaust port 6 and the end of the exhaust pipe 4 is fitted, resulting in poor workability.

Therefore, conventionally, the gasket 8 is deformed into an elliptical shape, and its long diameter is changed to the peripheral wall 7 of the exhaust port 6.
Is fitted with a frictional force to the inner diameter of the exhaust pipe 4 and temporarily held after the fitting, and the exhaust pipe 4 is fitted.

[0005]

However, when the gasket 8 is deformed into an elliptical shape, it can be prevented from falling off by using the long diameter, but the area where the periphery on the short diameter side contacts the contact surface of the exhaust port 6 is reduced. Thus, there is a problem that even if the gasket 8 is a perfect circle, the gasket 8 is displaced downward to cause lubrication displacement, and the upper seal becomes insufficient. For this reason, the width of the contact surface of the exhaust port 6 is made large to prevent gas leakage. However, this causes inconvenience such as enlarging the cylinder.

The present invention has been made in consideration of the above-described circumstances, and has as its object to provide a gasket for an internal combustion engine which does not fall off when fitted to a port without deforming the gasket. I do.

[0007]

In order to solve the above-mentioned problems, a gasket for an internal combustion engine according to the present invention is made of a stainless steel mesh, asbestos, or other sealing material formed by a circumferential groove around the outer periphery of a thin metal plate ring having a U-shaped cross section. In the gasket crimped inside, at least two protrusions are provided on the outer periphery of one of the side walls of the thin metal plate ring, and the dimension from the center of the gasket to the tip of the protrusion is set to the inner circumference of the port peripheral wall of the exhaust port. The gasket is inserted into the exhaust port with the side wall provided with the projection facing the inner side of the exhaust port while being formed slightly larger than the radius.

[0008]

[Action] When a gasket is inserted into the peripheral wall of the port,
The protrusions on the outer periphery are fitted in a state where they are in contact with the inner surface of the peripheral wall portion, and do not fall off even if the hand is released from the gasket. Therefore, if the gasket is fitted and then the end of the pipe to be connected is inserted and fastened, the gasket can be interposed at the correct position without misalignment, thereby reliably preventing gas leakage.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

The gasket 10, as shown in cross section in FIG. 1, is composed of a stainless steel mesh, asbestos, and other sealing material 11 as in the prior art, and a thin metal plate ring 12 covering the sealing material 11. The thin metal plate ring 12 is formed in a U-shaped cross section so that a circumferential groove 13 that opens radially outward is formed in the outer peripheral portion. The sealing material 11 is formed in the outwardly open circumferential groove (outer circumferential groove) 13. Is filled. Metal sheet ring 1 filled with sealant 11
The side wall portions 13a and 13b of the second circumferential groove 13 are crimped from both sides to hold the sealing material 11.

At least two (FIG. 2) or three (FIG. 3) projections 14.14 are formed on the outer periphery of the side wall 13a forming the peripheral groove 13. As for the height of the projection 14, the dimension from the center of the gasket 10 to the tip of the projection 14 is slightly larger than the radius of the inner circumference of the peripheral wall 7 of the exhaust port 6.

Therefore, when the projections 14, 14,... Are pushed into the peripheral wall portion 7 of the exhaust port 6 with the projections on the back side, the projections 14, 14,. You. It is preferable to provide the projections 14, 14,... At three locations at equal intervals as shown in FIG. If the pipe 4 is inserted and fastened in this manner, a gasket 10 is interposed between the pipe 4 and the exhaust port 6 to prevent gas leakage. FIG. 4 is an enlarged partial cross-sectional view showing a portion corresponding to the portion A shown in FIG.

[0013]

As described above, according to the present invention, since the metal ring of the gasket is a thin plate, the gasket is pushed into the peripheral wall portion of the exhaust port when the gasket is assembled, so that the plurality of rings of the metal thin plate ring are formed. The projections are easily deformed by engaging with the peripheral wall of the port, and are temporarily held stably without misalignment. Then, the pipe can be inserted and tightened, so that the assembling work becomes extremely easy and the gasket is misaligned. There is no gas leakage. This makes it possible to reduce the width of the abutting surface on the exhaust port side where the gasket contacts, thereby reducing the size of the cylinder.In addition, the gasket is inserted with the side wall on the protruding side facing the back side of the exhaust port. Even if the projection is deformed due to the insertion of the gasket, since the projection deformation is a bending deformation toward the front side accompanying the insertion of the gasket, it is possible to prevent the adverse effect on the sealing surface of the gasket beforehand and surely, By increasing the surface pressure of the gasket, the sealing function of the high-pressure gas can be enhanced, and the reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing one embodiment of a gasket for an internal combustion engine according to the present invention.

FIG. 2 is a front view of a gasket for an internal combustion engine.

FIG. 3 is a front view showing a modification of the gasket for the internal combustion engine.

FIG. 4 is a sectional view showing a state in which the gasket for an internal combustion engine according to the present invention is fitted to an exhaust port of a cylinder head.

FIG. 5 is a half sectional view showing a conventional gasket.

FIG. 6 is a cross-sectional view showing an example of a conventional gasket mounting portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Seal material 2, 12 Ring 3, 13 Peripheral groove 4 Exhaust pipe 6 Exhaust port 7 Peripheral wall part 8, 10, Gasket 14 Projection

Claims (1)

(57) [Scope of request for utility model registration] 1. A gasket in which a stainless steel mesh, asbestos, or other sealing material is caulked in a circumferential groove around the outer periphery of a thin metal plate ring having a U-shaped cross section. Protrusions are provided at at least two places on the outer periphery, and the dimension from the center of the gasket to the tip of the protrusions is formed slightly larger than the radius of the inner periphery of the port peripheral wall portion of the exhaust port, while the side wall provided with the protrusions is located on the back side of the exhaust port. A gasket for an internal combustion engine, wherein the gasket is inserted into an exhaust port.