JPH0613435Y2 - Metallic laminated gasket for cylinder head - Google Patents

Description

TECHNICAL FIELD The present invention relates to a metal laminated gasket for a cylinder head.

2. Description of the Related Art Cylinder holes and liquid holes such as oil holes have different sealing environments due to factors such as engine heat load and cylinder pressure. Therefore, in cylinder head metal laminated gaskets that are interposed between the cylinder block and head. So that the circumference of the cylinder hole fits the environment around the cylinder hole, and
A seal portion is provided around each liquid hole so as to match the environment around the liquid hole.

With a structure that seals both holes around the cylinder hole and the liquid hole while maintaining a balance, a bead surrounding the cylinder hole is provided around the cylinder hole to generate sealing surface pressure, while a gasket is installed around the liquid hole. A seal ring separate from the constituent plates such as the upper plate to be configured is provided to generate the necessary seal surface pressure around the liquid hole, and the seal surface pressure by the seal ring should be lower than the seal surface pressure by the bead. There is one (first conventional example).

Further, there is a laminated gasket having a structure in which a plate coated with rubber such as NBR rubber is arranged on a component plate without using a seal ring, and beads surrounding the cylinder hole and the liquid hole are arranged (second conventional example).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In a first conventional example, a seal ring is prepared separately from the gasket and is used by interposing it between a cylinder head and a block together with the gasket when assembling the engine, or It is necessary to assemble the seal ring with the gasket component plate at the time of assembling the gasket, or to prepare the seal ring in any case. Therefore, there is a possibility that misassembly may occur and a defective product of the gasket or the engine may occur.

Further, in the second conventional example, since the bead surrounding the cylinder hole has a rubber coating layer, there is a drawback that the coating layer deteriorates due to the high temperature of the cylinder hole and the durability is poor. Therefore, the material of the coating layer is fluororubber or the like. The construction is simple, but the cost is high.

In view of such a situation, the present invention has been devised for the purpose of eliminating the drawbacks of the conventional example and providing a metal laminated gasket for a cylinder head which has a simple structure and can seal a cylinder hole and a liquid hole in a well-balanced manner. It is a thing.

Means for Solving the Problem An upper plate, a lower plate and a middle plate constitute a gasket main body, an inner fold portion surrounding the cylinder hole is provided by folding back an end portion of the middle plate of the gasket body, and the inner fold portion is The upper plate or the lower plate is disposed inside the outer folded portion that constitutes the cylinder hole provided by folding back,
A suitable sealing plate such as the middle plate of the gasket main body is provided with a coating layer for liquid sealing outside the outer folded portion, and the coating layer is layered between the respective constituent plates such as the middle plate of the gasket main body. The configuration is as described above.

Embodiments The drawings show one embodiment of the metal laminated gasket for a cylinder head of the present invention, FIG. 1 is a partial plan view, FIG. 2 is a sectional view taken along the line IA-IA of FIG. A
Is equipped with a cylinder hole Hc, a bolt hole Hb, a water hole Hw, an oil hole Ho and a push rod hole Hp, similar to the conventional metal laminated gasket for a cylinder head.
The oil hole Ho and the push rod hole Hp are designed to be sealed by the same means, and the IA-I shown in FIG.
The sectional view taken along the line A shows the sealing means for the water hole Hw and the cylinder hole Hc.

As shown in FIG. 2, the gasket A constitutes a main body with an upper plate 1, a lower plate 2 and an intermediate plate 3 interposed between the upper plate 1 and the lower plate 2, and the upper plate 1 is a lower plate. An outer folded portion 4 that is folded back in two directions to form the cylinder hole Hc is provided, and an inner folded portion 5 that surrounds the cylinder hole Hc that is formed by folding the end of the middle plate 3 inside the outer folded portion 4 is provided.
To form the cylinder hole seal portion 6, and elastic coating layers 7, 7 are provided on the entire upper surface and lower surface of the intermediate plate 3 located outside the cylinder hole sealing portion 6, and the coating layer 7, 7 are layered between the gasket-constituting plates of the upper plate 1, the lower plate 2 and the middle plate 3, and the bead 8 whose top contacts the coating layer 7 on the lower surface side of the middle plate 3 surrounds the water hole Hw. The bead 8 provided on the lower plate 2 is used as a water hole seal portion 9.

The oil hole Ho and the push rod hole Hp are also provided with an oil hole seal portion 9a and a push rod hole seal 9b similar to the water hole seal portion 9, respectively.

The coating layer 7 is preferably made of rubber such as NBR rubber or silicone rubber, and elastic resin such as silicone resin may be used, and the optimum thickness is 10 to 50 μm.

A coating layer may be provided on the lower surface of the upper plate or the upper surface of the lower plate 2 so that the coating layer is layered between the gasket constituent plates.

Effect of the Invention As described above, according to the present invention, since the inner fold-back portion obtained by folding back the end portion of the middle plate is disposed inside the outer fold-back portion provided by folding back the upper plate or the lower plate, the portion is the sealing surface. Cylinder hole can be surely sealed by ensuring pressure, and the gasket layer affects the sealing function without affecting the sealing function. Leakage can be prevented in advance.

Further, according to the present technology, all the materials constituting the above-mentioned coating layer are weak against heat, and it is not possible to prevent the material from being damaged or deteriorated by high heat. However, according to the present invention, the coating layer is the sealing portion of the cylinder hole outside. Since it is arranged on the outer side of the folded-back portion, the liquid sealing can be performed without trouble without being affected by high heat, and the cylinder hole sealing function due to the presence of the coating layer in the outer-folded portion does not decrease. A metal laminated gasket for a cylinder head having excellent sealing performance can be provided.

[Brief description of drawings]

The drawings show an embodiment of a metal laminated gasket for a cylinder head according to the present invention. FIG. 1 is a partial plan view and FIG. 2 is a sectional view taken along the line IA-IA in FIG. 1 ... upper plate, 2 ... lower plate, 3 ... middle plate, 4 ... outer folded portion,
5 ... Inner folded portion, 7 ... Coating layer, Hc ... Cylinder hole

Claims (1)

[Scope of utility model registration request] 1. A gasket main body composed of an upper plate, a lower plate and an intermediate plate, wherein an inner folded portion surrounding the cylinder hole by folding back an end portion of the middle plate of the gasket body is provided. A liquid seal is provided inside the outer folded portion that forms the cylinder hole formed by folding back the upper plate or the lower plate, and is placed outside the outer folded portion on an appropriate component plate such as the middle plate of the gasket body. A metal laminated gasket for a cylinder head in which a coating layer for a cylinder head is provided, and the coating layer is layered between constituent plates such as the middle plate of the gasket body.