JPH0334517Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a local high-density gasket mainly made of fibrous material such as asbestos.
In more detail, the air in the fiber material is
The present invention relates to a locally high-density gasket that prevents liquid from permeating into the gasket and leaking through the gasket.

[Conventional technology]

Gasket G is inserted between opposing flanges 1 and 2 as shown in Fig. 1, and is used by tightening bolts 3 between these flanges 1 and 2, and a large tightening force is obtained. In some cases, when using a gasket made mainly of fibers such as asbestos, the liquid distribution holes are filled with a liquid as shown in Figure 2 to prevent the liquid from penetrating into the gasket through the spaces between the fibers. A grommet (metallic ring) 5 is used to prevent liquid penetration.

[Problem to be solved by the invention] Gaskets in which the grommet is provided around the liquid hole cannot be treated to prevent such penetration due to restrictions such as manufacturing cost and usage conditions, so that the flowing liquid may penetrate into the gasket material. Many accidents occur due to leakage.

Most of the causes of the permeation leakage are due to the liquid W permeating P through the minute voids in the fibrous tissue of the gasket body 6.

In a gasket having liquid circulation holes and mainly made of a fiber material, the voids of the fiber material are
It is an object of the present invention to provide a gasket mainly made of a fibrous material such as asbestos, which prevents the liquid in the liquid distribution hole from penetrating into the gasket and leaking through the gasket.

[Means to solve the problem]

The structure of the local high-density gasket of the present invention to achieve the above object is to form a liquid circulation hole in a flat gasket body which is mainly made of a fiber material and has a cavity between the fiber materials. The inner periphery of the liquid circulation hole is compressed more strongly toward the liquid circulation hole to form a dense portion that closes the void toward the inner side.

The present invention is an extremely effective structure when a leakage prevention method such as a grommet cannot be used in the seal hole due to the shape of the hole to be sealed, lack of sealing surface pressure, cost, or other reasons.

That is, by compressing the inner periphery of the liquid circulation hole more strongly as it approaches the liquid circulation hole, the air is sufficiently closed over the entire circumference to prevent liquid from penetrating, while maintaining adhesion to the bonding surface. It works like this.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a sectional view of a main part showing a first embodiment of a gasket according to the present invention.

As shown in the drawing, the edge of the liquid flow hole 4 provided in the gasket body 6, which is mainly made of fiber material, or the edge and the area slightly away from the edge are compressed in advance to form a band-shaped gasket. The feature is that a dense portion 7 is formed.

When viewed microscopically, the material constituting the gasket body 6 has minute voids, but in the dense portion 7, the pushing force closes the microscopic voids, thereby preventing leakage. be able to.

FIG. 4 is a front view of a flange gasket of a cooling system for an internal combustion engine showing a second embodiment of the present invention, and FIG. 5 is a sectional view taken along line B-B in FIG. This is a gasket G in which a concentric dense portion is provided on the outside of the dense portion.

In this embodiment, the water hole 9 of the gasket G and the surrounding area thereof are compressed from above and below by a compressor such as a press equipped with a mold having a convex portion, and a double dense portion 7 is formed near the water hole 9. ,7' by forming
It is designed to prevent percolation leakage, and the permeation leakage prevention effect is further strengthened.

By the way, cylinder head gaskets are used to seal fluids such as engine combustion gas, lubricating oil, and cooling water (in the case of water-cooled engines) that have different sealing conditions such as internal pressure and temperature. There must be.

Generally, the seal surface pressure of each part is determined by how the total clamping load applied to the gas is distributed to each seal part, but in the design of a normal cylinder head gasket, the total clamping load is 50 to 50% of the total clamping load. 60%
is distributed to the sealing portion of the combustion chamber hole, and the rest is distributed to the sealing portion of liquid circulation holes such as the water hole 9 and push rod hole, and the flat portion.

Therefore, in small engines with a small total tightening load, there are many cases where the seal surface pressure is insufficient at the seal part of the liquid circulation hole, causing seepage leakage.

When the present invention is applied to a cylinder head gasket, it is possible to pre-compress it in a band shape at the edge of the liquid flow hole in the gasket body 6, which is mainly made of fiber material, or further outside near this edge. Since the dense parts 7 and 7' are provided in the gasket, there is no need for a large load that would make the liquid hole seal part dense using the tightening pressure when the gasket is installed, unlike conventional gaskets. It exhibits excellent sealing performance as a cylinder head gasket for small engines with a small total tightening load.

In addition, when implementing the present invention, when forming a large number of dense parts as shown in Fig. 5, better effects can be expected by adjusting the formation mode of the dense parts according to the usage conditions of the gasket, the state of the materials used, etc. can do. Although the embodiments of the present invention have been described above, it is believed that the present invention can be widely applied to prevention of liquid penetration and leakage.

To talk about its overall advantages, the mainstream of heat-resistant non-metallic gaskets has traditionally been fibrous gaskets such as asbestos, but the weakness of these gaskets has been their permeability to liquids. . Therefore, if gaskets are used in areas where the tightening load is weak or where the surface pressure is partially weak, seepage leakage may occur. To prevent this, gaskets made of various complex and high-grade materials are used, but none of them are effective. The cost is high, the range of application is narrow, and the results are far from perfect.

[Effect of idea]

Since the local high-density gasket of the present invention is configured as explained above, the following effects can be obtained.

That is, by compressing the inner periphery of the liquid distribution hole more strongly as it approaches the liquid distribution hole, a dense portion is provided on the inner periphery of the liquid distribution hole that comes into contact with the liquid to prevent the liquid from penetrating, and the area around the liquid distribution hole is compressed more strongly. Since the adhesiveness between the gasket surface and the joint surface can be maintained, it is possible to provide a gasket that does not allow liquid to leak.

Moreover, in the micro-dense areas other than the above-mentioned dense areas, sufficient air space is maintained between the fibers, so that they can deform sufficiently in response to tightening and come into close contact with the joint surface, resulting in sufficient sealing ability. .

Therefore, it is possible to provide a gasket mainly made of an extremely reliable fiber material.

In addition, the gasket of the present invention is easy to manufacture because it is only necessary to provide a dense part that closes the voids between the fibers around the fluid circulation hole during the manufacturing process of conventional gaskets mainly made of fiber materials. , which is extremely advantageous in terms of cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a conventional gasket attached to a fluid flow pipe, and FIG. 2 is a sectional view of a conventional gasket with a grommet. FIG. 3 is a sectional view showing the main parts of a gasket according to the first embodiment of the present invention. FIG. 4 is a front view of a gasket provided in a conduit of a cooling system of an internal combustion engine, and FIG. 5 is a sectional view taken along line B--B of the gasket shown in FIG. 1, 2...flange, 3...bolt, 4...liquid flow path, 5...grommet, 6...gasket body, 7,
7'...Dense part, 9...Water hole, G...Gasket.

Claims (1)

[Scope of utility model registration request] A liquid circulation hole is formed in a flat gasket body which is mainly made of a fibrous material and has a space between the fibrous materials, and the inner peripheral edge of the liquid circulation hole is compressed more strongly toward the liquid circulation hole. A local high-density gasket that forms a dense area that blocks the air.