JPH0527427U - Metal gasket - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a metal gasket that exhibits a high degree of sealing properties and is highly durable. [Structure] First ridges 9 and 10 are formed around a bore hole 2 and a through hole 4 formed in a thin metal plate 16, and a second ridge 11 is formed around both ridges 9 and 10. First ridge 9,
Surface layers 14, 14 made of a soft metal such as lead are formed in a portion 13 between the 10 and the second protrusion 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is used as a cylinder head gasket which is sandwiched between the lower surface of a cylinder head and the upper surface of a cylinder block of an internal combustion engine to maintain airtightness and liquid tightness between both surfaces.

[0002]

[Prior Art]

 A cylinder head gasket is sandwiched between the lower surface of the cylinder head and the upper surface of the cylinder block of the internal combustion engine to allow high-pressure combustion gas generated in the cylinder or cooling water or lubrication flowing between the cylinder block and the cylinder head. Prevents oil from leaking to the outside.

FIG. 5 shows an example of such a cylinder head gasket 1. This cylinder head gasket 1 has circular bore holes 2 and 2 matching the opening shape of the cylinder top, small circular holes 3 and 3 through which bolts for fixing the cylinder head to the cylinder block are inserted, cooling water and lubrication. Through holes 4 and 4 for passing oil are provided.

Conventionally, such a cylinder head gasket 1 is made of a single metal thin plate such as a galvanized steel plate or a stainless steel plate in which the bore hole 2 and the like are punched, or a plurality of such metal thin plates are stacked. It is composed by.

FIG. 6 shows a first example of such a conventional metal cylinder head gasket. The metal cylinder head gasket illustrated in FIG. 6 has sealing layers 5 and 5 made of nitrile butadiene rubber (NBR), silicon rubber, fluorine rubber or the like formed on both front and back surfaces of a thin metal plate by means of baking or the like. A bank-shaped first ridge 6 is formed around each bore hole 2, and a diaphragm-shaped second ridge 7 is formed around each through hole 4 in a state of enclosing the entire circumference of each hole 2, 4. By doing so, the peripheral portions of the bore hole 2 and the through hole 4 can be kept airtight or liquidtight.

Further, in the structure of the second example shown in FIG. 7, a metal gasket is formed by stacking three metal thin plates. In the case of such a stacking structure, a layer of sealing material 5 is formed on both front and back surfaces of the metal thin plate in the middle part to maintain the airtightness and liquid tightness of the overlapping surface of the metal thin plates. There is.

[0007]

[Problems to be solved by the device]

 However, in the case of the conventional metal gasket configured as described above, since rubber is used as the sealing materials 5 and 5, it cannot be said that the heat resistance is always sufficient, and with long-term use, It is unavoidable that the sealing performance gradually deteriorates.

When a soft metal such as lead, a lead alloy, or high-purity aluminum is used as the sealing material 5 or 5 instead of rubber, sufficient performance can be obtained from the viewpoint of heat resistance. Even if the structure shown in FIG. 7 is used and the sealing materials 5 and 5 are replaced with soft metal layers, it is still impossible to obtain a sufficient sealing property for a long period of time.

That is, since the soft metal has a slight fluidity, if the soft metal layer is simply formed on the surface of the thin metal plate, the upper surface of the cylinder head and the lower surface of the cylinder block will be formed over a long period of time. The force of pressing the metal gasket when the metal gasket is held between the two surfaces to be sealed, for example, between the two surfaces to be sealed, when the soft metal gradually comes out (flows) from the part where the pressing force is strong. Will be weakened and the sealing performance will be insufficient.

The metal gasket of the present invention eliminates the above-mentioned inconvenience.

[0011]

[Means for solving the problem]

 The metal gasket of the present invention is formed on a thin metal plate, and has a through hole through which a fluid flows, a first ridge surrounding the through hole, and a first ridge provided around the first ridge. A second protrusion and a surface layer made of a soft metal attached to the surface of the above-mentioned thin metal plate in a portion between the second protrusion and the first protrusion. ..

[0012]

[Action]

 In the case of the metal gasket of the present invention configured as described above, the soft metal forming the surface layer in the portion between the first ridge and the second ridge exists on the surface to be sealed. By deforming along such irregularities, the gap between the surface layer and the surface to be sealed is eliminated, and good sealing performance is secured.

Further, since the surface layer is provided in the portion between the first ridge and the second ridge, the soft metal forming the surface layer spreads in the plane direction. , Blocked by the second ridge. Therefore, the thickness of the surface layer does not decrease with the flow of the soft metal, and the metal gasket keeps the sealing property between the two surfaces in a good state for a long period of time.

[0014]

【Example】

 1 to 3 show a first embodiment of the present invention. In this first embodiment, a metal cylinder head gasket is constructed by one thin metal plate 16. In the thin metal plate 16, circular bore holes 2 and 2 matching the opening shape of the cylinder top, small circular holes 3 and 3 through which bolts for fixing the cylinder head to the cylinder block are inserted, and cooling water and lubricating oil are provided. Through holes 4 and 4 for passing through are provided. Further, grommets 8, 8 formed by folding an annular thin metal plate into a U-shaped cross section are mounted around the bore holes 2, 2.

Then, first ridges 9 and 10 are formed around the bore holes 2 and 2 and the through holes 4 and 4 which are the flow holes. Further, a second protrusion 11 is formed near the outer peripheral edge of the metal thin plate 16 over the entire circumference of the metal thin plate 16. Further, among the holes 2, 3 and 4 described above, the bore holes 2 and 2 and the through holes 4 and 4 except for the small circular holes 3 and 3 for bolt insertion are provided inside the second protrusion 11. ing. A shim 12 made of a thin metal plate is fixed by spot welding to an outer peripheral portion of the thin metal plate 16 outside the second protrusion 11.

Further, in the portion 13 between the first ridges 9 and 10 and the second ridge 11, which is shown in a slanted lattice in FIG. 1, lead and the like are formed on both front and back surfaces of the metal thin plate 6. Surface layers 14 and 14 made of soft metal are attached. The work of attaching the surface layers 14 and 14 is performed by, for example, adhering a soft metal sheet punched in a predetermined shape (shape of the slanted lattice in FIG. 1) to both the front and back surfaces of the metal thin plate 16. Do things.

As described above, the metal gasket of the present invention, which is constructed as a cylinder head gasket, is sandwiched between the upper surface of the cylinder block and the lower surface of the cylinder head so as to maintain the airtightness and the liquidtightness between the both surfaces. In this case, the soft metal forming the surface layers 14, 14 in the portion 13 between the first ridges 9, 10 and the second ridges 11 exists on the upper surface of the cylinder block to be sealed and the lower surface of the cylinder head. By deforming along the subtle unevenness, the gaps between the surface layers 14, 14 and the upper surface of the cylinder block and the lower surface of the cylinder head are eliminated. As a result, fluid such as combustion gas, lubricating oil, or cooling water does not leak between the surface layers 14, 14 and the upper surface of the cylinder block and the lower surface of the cylinder head. Good sealing property between the two.

Further, each surface layer 14, 14 is provided in a portion 13 between the first ridges 9, 10 and the second ridge 11, and in the use state of the cylinder head gasket, these gaps As shown in FIG. 3, both sides of the minute portion 13 are closed, so that the soft metal forming the respective surface layers 14, 14 does not spread in the surface direction. Therefore, the thickness of the surface layers 14 and 14 does not decrease with the flow of the soft metal, and the cylinder head gasket, which is the metal gasket of the present invention, prevents the thickness between the cylinder block upper surface and the cylinder head lower surface. The sealing property is maintained in a good state for a long time.

The thickness of each part of the cylinder head gasket is appropriately selected according to the required sealing property. For example, when configuring a cylinder head gasket to be installed in an average engine, the thickness of each part is It can be set as follows. That is, the thickness of the metal thin plate 16 is 0.3 mm, the height of each ridge 9, 10, 11 is 0.45 mm, and the thickness of the metal thin plate forming the grommet 8 is 0.25 mm. As a result, the thickness of the grommet 8 is set to 0.5 mm, the thickness of the shim 12 at the outer peripheral edge portion is set to 0.3 mm, and the surface layers 14 and 14 are each made of a lead sheet having a thickness of 0.2 mm. It is composed of

Next, FIG. 4 shows a second embodiment of the present invention. In the case of the present embodiment, a cylinder head gasket, which is a metal gasket, is constructed by stacking two metal thin plates 16, 16. The surface layers 14 and 14 made of soft metal are formed only on the surfaces of the metal thin plates 16 and 16, and are not formed on the back surface portion sandwiched between the metal thin plates 16 and 16. In addition to mounting the grommet 8 on the inner peripheral edge of the bore hole 2, the eyelet 15 made of a thin metal plate is mounted on the inner peripheral edge of the through hole 4. Other configurations and operations are the same as those in the case of the above-described first embodiment.

[0021]

[Effect of the device]

 The metal gasket of the present invention is constructed and operates as described above, but even if there is a slight unevenness on the surface to be sealed, the surface layer made of soft metal is deformed along this unevenness, and this surface and the metal are A high degree of sealing performance can be obtained because a gap is not formed between the gasket and the gasket. Furthermore, the flow of the soft metal that constitutes the surface layer is prevented by the first and second ridges, and this is combined with the fact that the soft metal has excellent heat resistance, resulting in a good long-term The sealing property can be maintained.

[Brief description of drawings]

FIG. 1 is a partial plan view showing a first embodiment of a metal gasket of the present invention.

FIG. 2 is an enlarged AA sectional view of FIG.

FIG. 3 is a cross-sectional view corresponding to part B of FIG. 2, showing a crushed state.

FIG. 4 is a sectional view similar to FIG. 2, showing a second embodiment of the present invention.

FIG. 5 is a plan view showing an example of a metal gasket to which the present invention is applied.

FIG. 6 shows a first example of a conventional metal gasket, FIG.
A view corresponding to a C-C cross section of FIG.

FIG. 7 is a sectional view similar to FIG. 6, showing a second example.

[Explanation of sign]

 1 Cylinder Head Gasket 2 Bore Hole 3 Small Circle Hole 4 Through Hole 5 Sealing Material 6 First Protrusion 7 Second Protrusion 8 Grommet 9 First Protrusion 10 First Protrusion 11 Second Protrusion 12 Shim 13 Part 14 Surface layer 15 Eyelet 16 Metal thin plate

Claims (1)

[Scope of utility model registration request] 1. A flow hole formed in a thin metal plate for allowing a fluid to flow inside, a first ridge surrounding the flow hole, and a second ridge provided around the first ridge. Ridges,
In the portion between the second ridge and the first ridge,
A metal gasket provided with a surface layer made of a soft metal, which is attached to the surface of the metal thin plate.