JPH0520926Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a metal gasket, and particularly to a metal cylinder head gasket using a silicone rubber layer as a surface sealing material.

[Conventional technology]

For metal cylinder head gaskets used in automobile engines and the like, a composite plate structure has been developed in which layers of elastic metal plates are stacked with beads or the like between upper and lower flat metal plates. However, when the metal gasket was tightened to the cylinder, problems arose, including high restorability, manufacturing cost, and weight.

Therefore, a metal gasket having a single metal plate structure having a convex or step-shaped bead has been developed, but this has caused the problem that the bead part damages the cylinder head part in contact with the gasket. Therefore, as shown in FIG. 5, for example, a stainless steel plate 10 is used as a substrate, a fluorine rubber vulcanized layer 11 with a thickness of about 5 to 10 μm is applied to the surface of the substrate, and a fluorine rubber vulcanized layer 11 with a thickness of about 10 to 20 μm is further applied on the surface of the substrate. A metal cylinder gasket coated with a non-vulcanized layer 13 of raw rubber has been proposed.

[Problem that the invention attempts to solve]

Fluoro rubber vulcanized layer 11 and fluoro rubber non-vulcanized layer 1
A practical total layer thickness of 3 is 20 to 30μ. However, if the combined thickness of the two layers is less than about 10 μm, sealing failure will occur, and if it is more than about 50 μm, the axial force of the bolt will decrease due to settling. Therefore, controlling the layer thickness on the surface of the stainless steel plate 10, which is a metal substrate, is a very important issue. Furthermore, the surface roughness of the cylinder block, which is the mating surface of the metal gasket, must be fine and below a certain value in order to improve sealing performance. Furthermore, fluorocarbon rubber is more expensive than silicone rubber, and its compatibility with the mating surface is poor, and perfect sealing performance cannot be ensured.

Therefore, an object of the present invention is to provide a metal gasket with improved sealing performance and improved compatibility with the mating surface of the metal cylinder head gasket.

[Means for solving problems]

The above problem is solved according to the present invention, in which a metal cylinder head gasket having a metal substrate is coated with a sealing material made of silicone rubber on the surface of the metal substrate via a fluoro rubber layer. The problem is solved by a manufactured cylinder head gasket.

[Effect]

According to the present invention, the surface of the metal substrate is coated with high-strength fluoro rubber, and the fluoro rubber layer is further coated with silicone rubber that has good compatibility with the mating surface. This allows for a metal cylinder head gasket with good conformability, improving sealing performance without causing problems such as a decrease in axial force.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

Fig. 1 is a schematic cross-sectional view of a metal gasket, Fig. 2 is a cross-sectional view explaining the first embodiment of the present invention, and Fig. 3 is a cross-sectional view explaining the second embodiment of the present invention. be.

According to FIG. 1, the gasket body 1 has water holes 2,
A bolt hole 3, an outer peripheral bead 4, a combustion chamber opening 5, an oil hole 6, and a bore bead 7 are provided. 1st
In the gasket of the first embodiment shown in FIG. 2, which is a cross section taken along line A-A in the figure, for example, SUS3
Approximately 10 to 15 μm on the surface of stainless steel plate 10 such as 04
A fluororubber vulcanized layer 11 with a thickness of approximately 20 to 30 μm is formed on the surface thereof.

4A and 4B are sectional views showing the gasket of the first embodiment shown in FIG. 2 before and after tightening, respectively.

When the gasket having the bead 7 in the state shown in Fig. 4A is tightened, the bead 7 becomes as shown in Fig. 4B.
The silicone rubber is broken and cut in areas where the surface pressure is high, and the silicone rubber flows on both sides of the bead, improving the sealing performance of the gasket. The peaks of the bead 7 where the silicone rubber has flowed are sealed by the fluoro rubber vulcanized layer 11, and since the layer thickness is thin, sagging is reduced. In addition, since the general plane portion other than the bead 7 is sealed with thick silicone rubber, it has good compatibility with the mating surface and can be sealed even on a surface with rough surface roughness.

Furthermore, in the gasket of the second embodiment shown in FIG. 3, which corresponds to the cross section taken along line B-B in FIG.
A fluoro rubber vulcanized layer 11 with a thickness of about 5 to 10 μm is placed on the surface of the stainless steel plate 10, and a layer of about 5 to 10 μm thick is further applied on the surface of the stainless steel plate 10.
A fluorocarbon non-vulcanized layer 13 with a thickness of 10 μm is provided, and the water holes 2 are closed except for the bead area.
(Figure 3) Around, oil hole 6 (not shown in Figure 3)
Silicone rubber layer 12 of approximately 10 to 20 μm around the circumference
is provided.

In other words, in addition to the conventional structure, the gasket shown in Fig. 3 has silicone rubber with better compatibility formed around the water holes and around the oil holes, combining the characteristics of fluorocarbon rubber and silicone. By designing the thickness to be appropriate, sealing performance can be improved and a decrease in axial force due to settling can be prevented.

[Effect of idea]

As explained above, according to the present invention, by combining fluorocarbon rubber and silicone rubber, sealing performance can be improved without causing problems such as a decrease in axial force, and cost can be reduced. Furthermore, there is no need to particularly improve the surface roughness of the block diagram, which is the opposing surface of the gasket, and layer thickness control is easier than ever.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a gasket according to the present invention; FIG. 2 is a schematic cross-sectional view of a gasket according to a first embodiment, which corresponds to the cross-section taken along line A-A in FIG. 1; FIG. 3 is a schematic cross-sectional view of a gasket according to a second embodiment, which corresponds to the cross-section taken along line B-B in FIG. 1;
Fig. 4A is a schematic cross-sectional view showing the state before tightening of the gasket shown in Fig. 2, Fig. 4B is a schematic cross-sectional view showing the state after tightening of the gasket shown in Fig. 2, and Fig. 5 is a schematic cross-sectional view of a conventional gasket. 1... gasket body, 2... water hole, 3... bolt hole, 4... outer peripheral bead, 5... combustion chamber opening, 6... oil hole, 7... bore bead, 11... fluorine vulcanized layer, 12... silicone rubber layer, 13...
...Fluorine non-vulcanized layer.

Claims (1)

[Scope of utility model registration request] 1. A metal cylinder head gasket having a metal substrate, characterized in that the surface of the metal substrate is coated with a sealing material made of silicone rubber via a fluoro rubber layer.