JPS6224029Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder head gasket for an internal combustion engine.

There are various types of cylinder head gaskets (hereinafter simply referred to as gaskets) for internal combustion engines.
There is something called a steel type gasket made of steel plates.

This has the advantage of being easy and inexpensive to manufacture, but due to its nature, there is a limit to its compatibility with the mating surface of the cylinder head and cylinder block.
If even a small amount of dust is trapped, there is a risk that the sealing performance will deteriorate.

Conventionally, this problem has been dealt with by forming coating layers such as plating or coating on the front and back surfaces of steel type gaskets for initial adaptation.

On the other hand, there are cases in which a method is adopted in which the sealing performance is ensured by locally increasing the surface pressure at the flange of the cylinder liner without forming a coating layer.

For example, as shown in FIG.
<0.1 mm), the gasket 5 is formed between the collar 2 and the cylinder head 5 when the cylinder head 5 is tightened with the gasket 4 in between.
The aim is to apply strong surface pressure to the surface.

According to this method, the sealing performance of an inexpensive steel type gasket without a coating layer can be improved simply by changing the dimensions of the cylinder liner 1 (flange portion 2).

However, with this method, the sealing performance is still insufficient, especially when high combustion pressure is applied as in a diesel engine, and combustion gas leaks mainly from between the cylinder head 5 and the gasket 4, which do not have a step h. There is a tendency to

The present invention was developed with attention to these points, and is used in internal combustion engines in which steps are formed on the mating surfaces of the cylinder head or cylinder block to increase the contact pressure with the gasket. An object of the present invention is to provide a sealing device that further improves performance.

Hereinafter, the present invention will be explained based on illustrated embodiments.

In FIG. 2, 1 is a cylinder liner, 2 is a flange thereof, 3 is a cylinder block, and 5 is a cylinder head, and these structures are the same as those in FIG. 1.

In contrast, in the steel type gasket 6 of the present invention, a coating layer 7 (for example, a relatively soft coating such as lead plating) is formed on the surface that comes into contact with the smooth mating surface of the cylinder head 5 without a step h.

As a result, the cylinder head 5 and the gasket 6 are sufficiently fitted together through the coating layer 7 to form a close contact state, so that the cylinder head 5 and the gasket 6
The sealing performance of the smooth surface between the two is significantly improved.

Further, since the covering layer 7 only needs to be formed on one side of the gasket 6, it is advantageous in terms of material cost and manufacturing cost.

FIG. 3 shows another embodiment of the present invention, which is an example of an internal combustion engine in which a step h is formed on the lower surface of the cylinder head 5 so as to face the flange 2 to increase the surface pressure of the flange 2. It is.

In this case, since the upper surface of the flange portion 2 and the upper surface of the cylinder block 3 form a smooth surface, the coating layer 7 of the gasket 6 is formed on the side that comes into contact with this surface. The sealing performance can be efficiently improved.

As described above, according to the present invention, since the coating layer is formed only on the side where the sealing effect due to the step is insufficient, the sealing performance of the steel type gasket is improved and the cost can be reduced. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a conventional example. Figure 2,
FIG. 3 is a sectional view of essential parts of each embodiment of the present invention. 1...Cylinder liner, 2...Brim, 3...
Cylinder block, 4, 6...Steel type gasket, 5...Cylinder head, 7...Coating layer, h...Step.

Claims (1)

[Scope of utility model registration request] Attach the cylinder liner to the cylinder block,
A cylinder liner flange and a cylinder block;
In a sealing device for an internal combustion engine, in which a steel type gasket is sandwiched between the cylinder head and a cylinder head facing the cylinder head, one of the mating surfaces that sandwich the steel type gasket is formed with a smooth surface and a step on the other side, A sealing device for an internal combustion engine, characterized in that a coating layer made of a soft material is formed only on the surface that comes into contact with the smooth surface of the steel type gasket.