JPH051727Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cylinder head gasket made of metal, and more particularly to a cylinder head gasket made of a metal plate provided with sealing beads at required locations.

Recently, metal plate cylinder head gaskets have been developed in which beads with a convex or stepped cross section are formed on an elastic metal plate, and these beads effectively seal the joint surface between the cylinder head and cylinder block of an internal combustion engine. Proposed.

In this type of cylinder head gasket, in order to seal the high-pressure combustion gas generated in the combustion chamber of the engine, a bead is formed protruding around the combustion chamber hole provided in the gasket, and this part is made thicker than other parts. Various proposals have been made to obtain high contact pressure.

Among these proposals, there is one in which a soft material such as rubber is filled into the recess on the back side of the bead formed around the opening (see Japanese Utility Model Publication No. 1983-5920), and one in which a hard material is filled in the groove on the back side of the bead around the opening. A ring is embedded in the ring (Japanese Utility Model Application Publication No. 57-59249), and a metal plate thinner than the height of the bead around the opening is laminated near the bead to maintain the elastic force of the bead for a long time (Utility Model Application No. 59/1989).
-188955), a thick member such as a shim plate or sprayed material is formed on one side of the inner peripheral edge on the side of the combustion chamber hole from the combustion chamber hole peripheral bead, and the joint surface is connected to the combustion chamber hole peripheral edge of the gasket. A gasket designed to reduce the gap (see Japanese Utility Model Application Publication No. 14748/1983) has an annular groove surrounding an opening such as a water hole on both sides of the gasket, and coats this annular groove with a sealant such as silicone resin. (Utility Model Application No. 60-18247), a sub-plate is provided on both sides of the gasket board, and the sub-plate is
There is one in which a rubber member is attached to a portion of the gasket substrate corresponding to the peripheral bead of the water hole to prevent water leakage (see Japanese Utility Model Publication No. 154852/1983).

[Problem that the invention attempts to solve]

As shown in the above examples of conventional gaskets, when a bead is formed on the periphery of the opening, for example, when this gasket is inserted into the joint surface between the cylinder head and the cylinder block, the gasket can be used as shown in Fig. 7. When the cylinder head 20 is tightened against the cylinder block 30, the bead portion 6 is compressed and deformed, and a space S or a low surface pressure portion is created at the base of the bead portion. Further, as shown in FIG. 6, a gasket having a thick wall portion 10 such as a shim plate formed in the vicinity of the bead 6 (see the above-mentioned Utility Model Application Publication No. 14748/1983, Utility Model Application Publication No. 59/1999)
(see Publication No. 188955), the above-mentioned space S becomes even larger, and if there is a water hole 3 nearby, water will enter and accumulate in this area, corroding the metal gasket and reducing its durability. . Also, due to this space, combustion gas also tends to leak in the direction of the water hole.

In view of the above-mentioned problems, the present invention aims to prevent corrosion deterioration due to water penetration in a metal cylinder head gasket and improve its sealing performance against combustion gas and water.

[Means for solving problems]

According to the present invention, the above problem can be solved by forming an elastic metal plate, having openings such as a combustion chamber hole and a water hole, and forming a bead around the periphery of the combustion chamber hole. The cylinder head gasket has a thick walled portion on the inner edge flat portion on the side of the combustion chamber hole, wherein a sealing member softer than the metal plate is held at the root portion of the bead on the side of the water hole. This problem can be solved by a head gasket.

[Effect]

The cylinder head gasket of the present invention having the above structure is inserted between the cylinder head and cylinder block when installed in an engine, and when the cylinder head is tightened and fixed to the cylinder block, the bead around the combustion chamber hole of the gasket is compressed. It is deformed and a predetermined surface pressure is generated in this part. At this stage, the cylinder head is prevented from being further tightened by the thick wall portion near the bead portion, and the deformation of the bead portion is stopped. In this tightened state, the area or space where the surface pressure is low that occurs at the root of the bead is closed by the sealing member held at the root, thereby preventing water from entering this area from the water hole. This sealing member also functions to prevent leakage of combustion gas.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a plan view showing the entire embodiment of the present invention. The cylinder head gasket 1 is made of an elastic metal plate, such as a stainless steel spring plate, and has a horizontally long rectangular shape as a whole, and each cylinder is located in the center of the cylinder head gasket 1. 4 combustion chamber holes 2 at positions that match the cylinder bores of
(in the case of a four-cylinder engine) are aligned. Water holes 3 communicating with the cooling water passages are provided on both side edges of the gasket 1, facing each combustion chamber hole 2, and oil holes 4 communicating with the lubricating oil passages are provided on the right side edge. . Additionally, a suitable number of bolt holes 5 are provided along the circumference of the gasket 1.

Annular beads 6, 7, and 8 are formed around the combustion chamber hole 2, water hole 3, and oil hole 4, respectively, and a bead 9 is formed around the entire periphery of the gasket 1. There is.

The structure of the combustion chamber hole peripheral bead 6 will be explained with reference to FIG.

The combustion hole peripheral bead 6 is formed by stamping near the outside of the combustion chamber hole 2 and has a semicircular cross section. Further inside this bead 6, that is, on the flat surface of the inner peripheral edge on the combustion chamber hole 2 side, a shim plate is placed toward the same side as the bead 6.
Thick-walled members 10 made of thermally sprayed members or the like are laminated and fixed. Note that the height of this thick member 10 is configured to be lower than the height of the bead 6.

A sealing member 12, which is softer than the metal plate constituting the gasket 1, is adhered and fixed to the root portion 11 of the bead 6 on the side opposite to the combustion chamber hole 2, that is, on the side of the water hole 3. This seal member 12 is made of heat-resistant resin. Further, a micro sealing material 13 is applied to the bead 6, the thick member 10, and the sealing member 12 to cover them.

A state in which the gasket 1 configured as described above is mounted on an engine will be explained.

Insert the gasket 1 into the joint between the cylinder head and cylinder block, and tighten the cylinder head against the cylinder block with a tightening screw. The bead 6 of the gasket 1 is compressively deformed, and a predetermined high surface pressure is generated at this portion. When a predetermined surface pressure is generated, the tightening of the cylinder head is prevented by the thick wall portion 10, and further deformation of the bead 6 is prevented. The gap between them is closed. On the other hand, due to the deformation of the bead 6,
A space or a low surface pressure area is created at the base 11, but this space is closed by the seal member 12, and therefore water from the water hole 3 that attempts to enter this space is blocked. Therefore, when the gasket 1 is used, water does not accumulate near the base of the bead 6, preventing corrosion and deterioration of the metal, and increasing the service life of the gasket 1. This seal member 12 also helps prevent leakage of combustion gas, and the sealing performance against high-pressure gas is further improved.

FIG. 3 shows a second embodiment of the invention. In this embodiment, a gasket 1 formed on site is used as a sealing member.
4 (abbreviated as FIPG).
FIPG belongs to the liquid gasket category, as opposed to molded gaskets made of paper, cork, rubber, etc., and generally refers to room-temperature vulcanizable silicone rubber sealants.

In this embodiment, by using the sealing member 14 as described above, an even greater sealing effect can be expected, and this sealing member 14 allows on-site construction and can be applied to places with complex shapes. .

FIG. 4 shows a third embodiment of the present invention. In this embodiment, an O-ring 15 is particularly used as the sealing member.

FIG. 5 shows a fourth embodiment of the present invention.

In this embodiment, a groove 16 is particularly provided at the base 11 of the beat 6, a seal member 17 is housed and held within the groove 16, and a seal member 18 is attached to the lower surface of the gasket outside of the groove 16. . With such a configuration, the sealing member 17 at the base can be held securely, and the sealing performance against water and gas is significantly improved.

In addition to rubber and resin, sealing materials include
Inorganic materials such as asbestos sheets can also be used.

[Effect of idea]

Since the present invention has the above-described structure and operation, it is possible to prevent the metal cylinder head gasket from being corroded and deteriorated due to water penetration, and to greatly improve the sealing performance against combustion gas and water. Furthermore, since the base of the bead does not corrode, this part can be prevented from cracking due to stress during use.

[Brief explanation of the drawing]

1 is an enlarged cross-sectional view of the main part of the first embodiment of the present invention taken along the line A-A in FIG. 2; FIG. 2 is a plan view showing the whole of the same embodiment; FIG. 4 is an enlarged sectional view of the main part of the second embodiment of the present invention, FIG. 4 is an enlarged sectional view of the main part of the third embodiment of the invention, FIG. 5 is an enlarged sectional view of the main part of the fourth embodiment of the invention, and FIG. is an enlarged sectional view of essential parts showing an example of a conventional cylinder head gasket,
FIG. 7 is a sectional view showing the conventional example in use. 1... Cylinder head gasket, 2... Combustion chamber hole, 3... Water hole, 6... Combustion chamber hole peripheral bead,
10... Thick walled member, 11... Bead base, 1
2... Seal member, 14... Field formed gasket, 15... O ring, 16... Concave groove, 17, 1
8... Seal member.

Claims (1)

[Claims for Utility Model Registration] 1. It is made of an elastic metal plate, has openings such as a combustion chamber hole, a water hole, etc., and has a bead formed by surrounding the periphery of the combustion chamber hole. A cylinder head gasket having a thick walled portion on a flat inner edge portion on the hole side, characterized in that a sealing member softer than the metal plate is held at the root portion of the bead on the water hole side. . 2. The cylinder head gasket according to claim 1, which is a registered utility model, wherein a groove is formed in the root portion, and the sealing member is accommodated and held within the groove.