JP2000145968A - Cylinder head gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head gasket capable of suppressing the bore deformation of an engine, and reducing the friction resistance of a piston or the oil consumption of the engine. SOLUTION: In a gasket main body 11, a combustion chamber hole 12, a bolt hole and an annular bore bead 14 are formed. On the surface of the gasket main body 11, a flexible heat resistant annular seal 17 is provided in a primary seal portion 16 provided along the peripheral edge of the combustion chamber hole 12. The heat resistant annular seal 17 is made of a heat resistant inorganic adhesive mainly containing ceramic particles and mixing a thermoplastic resin as a binder, and formed on the surface of the main body 11 by screen printing. Further, rubber coatings 18 are provided on the upper and lower surfaces of the main body 11 (including the upper and lower surfaces of the annular bore bead 14) and the exposed surface of the heat resistant annular seal 17 to cover the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head gasket for an engine.

[0002]

2. Description of the Related Art In a cylinder head gasket, a metal gasket main body is provided with a combustion chamber hole corresponding to the shape of a cylinder bore and a combustion chamber of a cylinder head, and an annular bore bead (secondary seal portion) is formed outside the combustion chamber hole. In addition, a cylinder head gasket has been proposed in which a heat-resistant annular seal (primary seal portion) is provided on one or both sides of a gasket main body at a peripheral edge of a combustion chamber hole between the annular bore bead and the combustion chamber hole. . Such a technique is disclosed, for example, in Japanese Utility Model Laid-Open No. 6-4466 and Japanese Patent Laid-Open No. 10-47.
No. 486.

When such a cylinder head gasket is used sandwiched between a cylinder block and a cylinder head, the annular bore bead exerts a sealing effect on a combustion chamber of the cylinder head, and is provided to the annular bore bead. When the annular bore bead is fully bent due to bolting or other excessive surface pressure, a heat-resistant annular seal called a stopper or shim exerts a supporting effect as the stopper, preventing the annular bore bead from fully bending and simultaneously preventing the combustion chamber from being bent. Exhibits a sealing effect.

[0004]

However, in the prior art, the annular bore bead is formed by curving the gasket main body in a semicircular cross section. On the other hand, the heat-resistant annular seal is formed by fixing another member having high rigidity to the gasket main body by thermal spraying, welding, an adhesive or the like. This heat-resistant annular seal has high rigidity and excellent sag resistance. On the other hand, the heat-resistant annular seal cannot be deformed so as to follow the contact surface shape (or deformation) of the fastened cylinder head and cylinder block, so that the surface pressure distribution around the combustion chamber becomes non-uniform. It is extremely difficult to adjust the surface pressure by changing the shape (for example, the plate thickness) entirely or partially. As a result, there is a problem that the deformation of the bore is increased, the frictional resistance of the piston is increased, and the oil consumption of the engine is increased.

An object of the present invention is to suppress the bore deformation of the engine by making the surface pressure distribution around the combustion chamber uniform,
An object of the present invention is to provide a cylinder head gasket capable of reducing frictional resistance of a piston and oil consumption of an engine.

[0006]

According to a first aspect of the present invention, a metal gasket body is provided with a combustion chamber hole adapted to the shape of a cylinder bore and a combustion chamber of a cylinder head. A primary seal portion is provided along the periphery of the combustion chamber hole, and a secondary seal portion is provided outside the primary seal portion. A point is that a flexible heat-resistant annular seal is formed in a step shape on at least one of both surfaces, and a bead formed by a gasket main body is formed in the secondary seal portion.

According to a second aspect of the present invention, in the cylinder head gasket according to the first aspect, the heat-resistant annular seal is mainly made of ceramic particles and mixed with a thermosetting resin as a binder. The gist is to consist of an adhesive.

According to the first aspect of the present invention, when the cylinder head gasket is clamped between the cylinder block and the cylinder head and fastened,
The heat resistant annular seal can be deformed by its flexibility to follow the contact surface shape of the cylinder head and the cylinder block. In other words, the shape of the heat-resistant annular seal can automatically or completely change according to the contact surface shape of the cylinder head and the cylinder block. As a result, the bore pressure deformation of the engine can be suppressed by making the surface pressure distribution around the combustion chamber uniform, and the frictional resistance of the piston and the oil consumption of the engine can be reduced.

According to the second aspect of the present invention, the first aspect is provided.
In addition to the effect of the invention described in the above, the heat-resistant annular seal is mainly composed of ceramic particles, because it is made of a heat-resistant inorganic adhesive mixed with a thermosetting resin as a binder,
The heat-resistant annular seal does not require fixing means such as thermal spraying, welding or other adhesives as in the prior art, and can be easily fixed to the gasket body by its own adhesiveness. As a result, man-hours and cost for manufacturing the cylinder head gasket can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view of the cylinder head gasket of the present embodiment. FIG. 2 is an enlarged view of a cross section taken along line AA in FIG.

[0011] The cylinder head gasket 1 of the present embodiment.
0 gasket body 11 is made of stainless steel plate,
As shown in FIG. 1, a combustion chamber hole 12 conforming to the shape of the combustion chamber of the cylinder bore and the cylinder head, and a bolt hole 13 for being inserted by a fastening bolt of the cylinder head and the cylinder block are formed by the press pressure processing. ing. At the same time, as shown in FIG. 2, an annular bore bead 14 as a bead having a longitudinal section having a semicircular arc shape is formed in the secondary seal portion 15 centering on the axis of each combustion chamber hole 12.

On the surface of the main body 11 on which the annular bore beads 14 are raised, a flexible heat-resistant annular seal 17 is provided on a primary seal portion 16 provided along the periphery of the combustion chamber hole 12. It is provided in a step shape. In this embodiment, the heat-resistant annular seal 17 is made of a heat-resistant inorganic adhesive mainly composed of ceramic particles and mixed with a thermosetting resin as a binder, and is formed on the surface of the main body 11 by screen printing. Is formed.

The thickness of the heat-resistant annular seal 17 is set so that when the annular bore bead 14 is fully bent and deformed, the heat-resistant annular seal 17 can exert a supporting effect as a stopper thereof.

Further, the cylinder head gasket 10 has upper and lower surfaces (an annular bore bead 1) of a main body 11 thereof.
4 and the exposed surface of the heat-resistant annular seal 17 is covered with a rubber coating 18.

[0015] Cylinder head gasket 1 of the present embodiment
According to 0, the following features can be obtained. (1) In the present embodiment, the cylinder head gasket 10
On the surface of the gasket main body 11, a flexible heat-resistant annular seal 17 is provided on a primary seal portion 16 provided along the periphery of the combustion chamber hole 12.

Therefore, when the cylinder head gasket 10 is clamped and clamped between the cylinder block and the cylinder head, the heat-resistant annular seal 17 follows the contact surface shape between the cylinder head and the cylinder block due to its flexibility. Can be modified as follows. That is,
The shape of the heat-resistant annular seal 17 can be automatically or wholly or partially changed according to the contact surface shape between the cylinder head and the cylinder block.

As a result, since the surface pressure distribution around the combustion chamber can be made uniform, the bore deformation of the engine can be suppressed, and the frictional resistance of the piston and the oil consumption of the engine can be reduced.

(2) In this embodiment, the heat-resistant annular seal 17 is made of a heat-resistant inorganic adhesive mainly composed of ceramic particles and mixed with a thermosetting resin as a binder. That is, the heat-resistant annular seal 17 itself has adhesiveness.

Accordingly, the heat-resistant annular seal 17 does not require fixing means such as thermal spraying, welding or other adhesives as in the prior art, and is easily fixed on the surface of the main body 11 by its own adhesiveness. Can be As a result, the man-hour and cost of manufacturing the cylinder head gasket 10 can be reduced.

(3) In this embodiment, the heat-resistant annular seal 17 is formed on the surface of the main body 11 by screen printing. Therefore, the heat-resistant annular seal 17 is
And the shape, width and thickness can be arbitrarily changed. As a result, the surface pressure distribution around the combustion chamber can be easily adjusted.

The embodiment of the present invention may be modified as follows. In the above embodiment, the thickness and width of the heat-resistant annular seal 17 are not particularly limited. However, if the support effect of the heat-resistant annular seal 17 as a stopper is obtained, the thickness and width may be arbitrarily changed. Is also good.

In the above embodiment, the heat-resistant annular seal 1
7 is provided on the surface of the main body 11 in which the annular bore bead 14 is raised, that is, provided on only one surface of the main body 11, but as shown in FIG.
May be provided on both surfaces of the main body 11 along the periphery of the combustion chamber hole 12. In this case, the same effect as the above embodiment can be obtained, and the sealing performance of the cylinder head gasket 10 can be further improved.

The heat-resistant annular seal 17 is not limited to a heat-resistant inorganic adhesive mainly composed of ceramic particles and mixed with a thermosetting resin as a binder. May be performed using an inorganic adhesive.
In this case, the same effect as in the above embodiment can be obtained.

In the above embodiment, the heat-resistant annular seal 1
7 was performed so as to be formed on the surface of the main body 11 by screen printing, but the heat-resistant annular seal 17 may be coated on the surface of the main body 11 by a general application method. Good. In this case, the same effect as in the above embodiment can be obtained.

In the above embodiment, the body 11 of the cylinder head gasket 10 is not limited to a stainless steel plate, but may be a metal plate other than a stainless steel plate, for example, a composite alloy steel plate, a copper plate, an aluminum plate, or the like. In this case, substantially the same effects as in the above embodiment can be obtained.

Next, technical ideas other than those described in the claims which can be understood from the above-described embodiment and other examples will be described below together with their effects. (1) The cylinder head gasket according to claim 1 or 2, wherein the heat-resistant annular seal is formed on at least one of both surfaces of the gasket main body by screen printing.

Therefore, in addition to the effects of the first or second aspect of the present invention, the heat-resistant annular seal can be easily formed on the gasket main body, and the shape, width and thickness can be arbitrarily changed. be able to. As a result, the surface pressure distribution around the combustion chamber can be easily adjusted.

[0028]

As described above, according to the first aspect of the present invention, the bore pressure of the engine is suppressed by making the surface pressure distribution around the combustion chamber uniform, and the frictional resistance of the piston and the engine are reduced. Oil consumption can be reduced.

According to the invention described in claim 2, according to claim 1
In addition to the effects of the invention described in (1), the number of manufacturing steps and cost of the cylinder head gasket can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a cylinder head gasket of the present embodiment.

FIG. 2 is an enlarged view of a cross section taken along line AA in FIG.

FIG. 3 is an enlarged cross-sectional view of another example cylinder head gasket.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Cylinder head gasket, 11 ... Gasket main body, 12 ... Combustion chamber hole, 13 ... Bolt hole, 14 ... Annular bore bead as bead, 15 ... Secondary seal part, 16 ... 1
Next seal part, 17: heat-resistant annular seal.

Claims (2)

[Claims] 1. A metal gasket main body is provided with a combustion chamber hole corresponding to the shape of the combustion chamber of a cylinder bore and a cylinder head, and a primary seal portion is provided along a peripheral edge of the combustion chamber hole. In a cylinder head gasket provided with a secondary seal portion outside the portion, a flexible heat-resistant annular seal is formed on at least one of both surfaces of the gasket main body in a step-like manner in the primary seal portion. The cylinder head gasket is characterized in that a bead formed by a gasket main body is formed in the secondary seal portion. 2. The cylinder head gasket according to claim 1, wherein the heat-resistant annular seal mainly includes ceramic particles.
A cylinder head gasket comprising a heat-resistant inorganic adhesive mixed with a thermosetting resin as a binder.