JPH0526382Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a gasket interposed in the joint surface of a cylinder head and a head cover used in an engine.

(Prior Art) Various proposals have been made to improve the sealing performance of cover gaskets that are interposed at joint surfaces between cylinder heads and head covers.

For example, Japanese Utility Model Application Publication No. 61-29165 discloses a gasket having a protrusion with bolt holes drilled therein, in which the bolt hole part is thin and the middle part between the bolt holes is thick. There is.

Furthermore, as shown in FIG. 5, a gasket 21 has been proposed in which a sealing ridge 22 is formed in an annular shape along the inner peripheral edge on the surface that abuts the mating surface of the other side, and the sealing ridge 22 is The bolt hole 23 is bent so as to pass through the inside thereof.

(Problem to be solved by the invention) However, in the gasket disclosed in Japanese Utility Model Application Publication No. 61-29165, it is actually difficult to make the surface pressure of the gasket uniform between the bolt hole part and the part between them. There was a problem in that it was difficult to ensure a perfect seal due to variations in conditions such as bolt tightening.

Furthermore, even when a sealing ridge is formed on the gasket as shown in Figure 5, the surface pressure due to tightening becomes uneven between the side where the sealing ridge is present and the side where the sealing ridge is not present at the bolt hole. This may adversely affect the surface pressure distribution of the seal protrusion, and the seal protrusion itself may be bent at the bolt hole.
When forming the seal protrusion, there was a problem that the flatness of the seal surface deteriorated at the bent portion, and it was difficult to obtain a perfect seal.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, the present invention aims to provide a gasket that can provide a more complete seal.

(Means for Solving the Problems) In order to achieve the above object, the present invention is designed to fit into an annular groove formed on one side of the smooth joint surfaces of both the cylinder head and the head cover, and to attach the cylinder head to the bolt hole in the bolt connection part. In the gasket, the protrusion is formed to protrude from the outer circumferential side of the gasket, and an annular seal protrusion is provided along the inner circumferential edge of the gasket on the surface that abuts the other joint surface of the gasket. , a circular seal protrusion is formed independently on the outside of the annular seal protrusion and extends along the periphery of each bolt hole, and the protrusion height of the annular seal protrusion and the circular seal protrusion are such that They are characterized by being substantially the same.

(Function) Since the present invention has the above-mentioned configuration, there is no need to bend the annular seal protrusion along the inner peripheral edge of the gasket at the bolt hole, so that a highly flat sealing surface can be formed. The length of the seal line can be shortened accordingly, and a circular seal protrusion is formed around the entire circumference of the bolt hole so that it has approximately the same protrusion height independently on the outside of the annular seal protrusion. Since the bolt tightening pressure is received uniformly, the seal by the annular seal protrusion is not adversely affected, and a more perfect seal can be obtained.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

In FIG. 4, reference numeral 1 denotes a head cover that covers the upper end opening of the cylinder head 2, and a gasket groove in which a gasket 5 is fitted is provided on a smooth joint surface 3 that faces a smooth joint surface 4 at the upper end of the cylinder head 2. 6 is formed. The gasket 5
As shown in FIG. 1, the planar shape surrounding the opening of the head cover 1 is formed into a rectangular ring shape.

The bolt fastening portion of the head cover 1 has a third
As shown by imaginary lines in the figure, a protrusion 7 is formed that protrudes toward the outer circumference, and a fastening hole 8 is formed in this protrusion 7 . Also, in the gasket 5, a protrusion 9 having a bolt hole 10 is formed to protrude toward the outer circumference at the bolt fastening portion, and the gasket groove 6 also has a protrusion that protrudes toward the outer circumference corresponding to the gasket 5. It is formed in a shape having a portion 6a.

The upper part of the gasket 5 is formed into a slightly narrow fitting part 5a that is press-fitted into the gasket groove 6, and has a surface 5 that comes into contact with the joint surface 4 of the cylinder head 2.
An annular sealing ridge 11 is formed along the inner peripheral edge of the gasket 5, and a circular sealing ridge 12 is formed around the bolt hole 10 in addition to the annular sealing ridge 11. As shown in Figure 3, they are formed to have the same protrusion height.

Next, to explain the operation, when installing the head cover 1, the gasket 5 is inserted into the gasket groove 6.
After the fitting part 5a is press-fitted and installed, the head cover 1 is placed on the joint surface 4 of the cylinder head 2, and the fastening hole 8 and the bolt hole 1 of the gasket 5 are connected.
The head cover 1 is fastened and fixed by screwing a fastening bolt into the cylinder head 2 through the bolt.

Then, the annular seal protrusion 11 of the gasket 5
is pressed against the joint surface 4 of the cylinder head 2 to form a seal. At this time, since the annular seal protrusion 11 is straight without being bent at the bolt hole 10 portion, the sealing surface can be formed in a highly flat state and high sealing performance can be ensured. Also, since the seal line length is shortened, there is less possibility of leakage occurring. Furthermore, in addition to the annular seal protrusion 11, a circular seal protrusion 1 is provided around the bolt hole 10.
2, the surface pressure caused by the tightening around the bolt hole 10 becomes uniform when the bolt is fastened, and the seal by the annular seal protrusion 11 is not adversely affected.

(Effects of the invention) According to the gasket of the invention, as described above, there is no need to bend the annular seal protrusion along the inner peripheral edge of the gasket at the bolt hole portion, so a highly flat sealing surface is formed. At the same time, the length of the seal line can be shortened accordingly, and the circular seal protrusion is formed around the entire circumference of the bolt hole, and the protrusion height is approximately the same on the outside of the annular seal protrusion. Since the bolt tightening pressure is uniformly received, the seal surface pressure due to the annular seal protrusion is not adversely affected, and a more perfect seal can be obtained.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a plan view of the gasket, FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIG. 3 is a sectional view taken along the - line in FIG. 1. FIG. 4 is a partially sectional front view of the device in use, and FIG. 5 is a partially plan view of the conventional example. 3, 4...Joint surface, 5...Gasket, 6...
Gasket groove, 9...protrusion, 10...bolt hole,
11...Annular seal protrusion, 12...Circular seal protrusion.

Claims (1)

[Scope of utility model registration request] In a gasket having a protrusion that is fitted into an annular groove formed on one of the smooth joint surfaces of both the cylinder head and the head cover and has a bolt hole drilled in the bolt fastening part, the protrusion is placed on the outer circumferential side of the gasket. The gasket has an annular seal ridge extending along its inner periphery on the surface that protrudes from the gasket and contacts the other joint surface of the gasket, and a periphery of each bolt hole located independently on the outside of the annular seal ridge. What is claimed is: 1. A gasket comprising: a circular seal protrusion extending along the circumference of the gasket; the protrusion heights of the annular seal protrusion and the circular seal protrusion being substantially the same.