JP2015178891A - cylinder head gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head gasket 1 capable of preventing the degradation and damage of rubber coating applied on surfaces of two gasket substrates 2, 3 due to combustion gas, and ensuring excellent sealability and long life.SOLUTION: Annular flat portions 2D and 3D are formed on both gasket substrates 2 and 3 to be adjacent to combustion chamber holes 2A and 3A, respectively, and half beads 2C and 3C raised on sides of the combustion chamber holes 2A and 3A are formed outward of the annular flat portions 2D and 3D, respectively. Entire surfaces of both gasket substrates 2 and 3 and an intermediate plate 4 are covered with rubber coating. If a cylinder head gasket 1 is held between a cylinder block 12 and a cylinder head 11, the annular flat portion 2D is firmly bonded to the cylinder head 11 and the annular flat portion 3D is firmly bonded to the cylinder block 12 by elasticity of the half beads 2C and 3C. Inner edges 2D' and 3D' of the annular flat portions 2D and 3D are firmly bonded to the intermediate plate 4 from upward and downward, respectively.

Description

  The present invention relates to a cylinder head gasket, and more particularly to a cylinder head gasket configured by laminating a plurality of gasket substrates.

Conventionally, a cylinder head gasket configured by laminating a plurality of gasket substrates is well known, and a cylinder head gasket in which a full bead is formed by surrounding each combustion chamber hole in each gasket substrate is also known (for example, Patent Document 1). reference).
In the cylinder head gasket disclosed in FIG. 2 and FIG. 3 of Patent Document 1, full beads are formed so as to oppose each adjacent gasket substrate in the upper and lower positions, whereby the sealing performance of the cylinder head gasket is achieved. Is intended to improve.

Japanese Patent No. 4314251

By the way, in the conventional cylinder head gasket including the cylinder head gasket of the said patent document 1, the surface of each gasket board | substrate is coat | covered with a coating material, thereby improving sealing performance. Yes. However, these conventional cylinder head gaskets also have a drawback that the sealing performance is likely to deteriorate with the passage of time after being mounted between the cylinder head and the cylinder block.
More specifically, as shown in an enlarged view in FIG. 5, the cylinder head gasket 1 of FIG. 3 of Patent Document 1 includes three gasket substrates 2 to 4 and shims 5. 4, full beads 2A to 4A are formed at positions where they surround the combustion chamber hole 1A and overlap each other, and the full bead 2A of the uppermost gasket substrate 2 has a shape bulging upward. And the rubber coating which is not shown in figure is given over the whole region of the front and back both surfaces of the three said gasket substrates 2-4.
When the cylinder head gasket 1 having such a configuration is sandwiched between the cylinder head 11 and the cylinder block 12, the lowermost gasket substrate 4 is in close contact with the cylinder block 12, and the top of the full bead 3A of the intermediate gasket substrate 3 is placed. And the tops of the full beads 4A of the lowermost gasket substrate 4 are in close contact with each other. Further, the uppermost gasket substrate 2 is in contact with the cylinder head 11, and the top of the full bead 2 </ b> A is in close contact with the cylinder head 11. Thereby, the seal between the cylinder head 11 and the cylinder block 12 is maintained by the cylinder head gasket 1.
However, the full bead 2A of the uppermost gasket substrate 2 is shaped to bulge upward, and the full bead 3A of the intermediate gasket substrate 3 is shaped to bulge downward. Therefore, when the cylinder head gasket 11 is sandwiched between the cylinder block 12 and the cylinder head 11, the gap between the gasket substrates 2 and 3 and the shim 5 that are adjacent to the combustion chamber hole 1 </ b> A is opened. A gap S1 is generated there. Further, the full bead 3A of the intermediate gasket substrate 3 and the full bead 4 of the lowermost gasket substrate 4 are in contact with each other with the bulging direction being reversed. Therefore, an opening is formed between the upper surface of the lowermost gasket substrate 4 adjacent to the combustion chamber hole 1A and the lower surface of the edge of the intermediate gasket substrate 3 above it, and a gap S2 is generated there. .
Therefore, when the engine is operated, the combustion gas in the combustion chamber hole 1A enters the gaps S1 and S2, and the rubber coating applied to the surfaces of the gasket substrates 2 to 3 is deteriorated and damaged by the combustion gas. As a result, there has been a drawback that the sealing performance of the cylinder head gasket 1 decreases with time.

In view of the circumstances described above, the first aspect of the present invention includes an upper first gasket substrate, a lower second gasket substrate, and an intermediate plate provided between the first gasket substrate and the second gasket substrate. In a cylinder head gasket in which combustion chamber holes are formed at predetermined positions of the first gasket substrate, the second gasket substrate, and the intermediate plate in a laminated state,
The first gasket substrate includes an annular flat portion surrounding the combustion chamber hole at an outer position adjacent to the combustion chamber hole, and surrounds the combustion chamber hole at an outer position adjacent to the annular flat portion. And the inner edge has a herb bead that rises from the intermediate plate than the outer edge,
The second gasket substrate includes an annular flat portion surrounding the combustion chamber hole at an outer position adjacent to the combustion chamber hole, surrounds the combustion chamber hole at an outer position adjacent to the annular flat portion, and The inner edge has a half bead that rises from the intermediate plate than the outer edge,
When the cylinder head gasket is sandwiched between the cylinder head and the cylinder block, the annular flat portion of the first gasket substrate is in close contact with the cylinder head and the annular flat portion of the second gasket substrate is in close contact with the cylinder block, Further, the inner edge of the annular flat portions of the gasket substrates is firmly attached to the intermediate plate from above and below.
The second aspect of the present invention includes an upper first gasket substrate, a lower second gasket substrate, and an intermediate plate provided between the first gasket substrate and the second gasket substrate. In the cylinder head gasket in which a combustion chamber hole is formed at a predetermined position of the first gasket substrate, the second gasket substrate, and the intermediate plate in a state,
At least one of the first gasket substrate and the second gasket substrate surrounds the combustion chamber hole at an outer position adjacent to the combustion chamber hole, and an outer edge portion is closer to an inner edge portion. Also includes a quarter bead that rises from the intermediate plate, and an annular flat portion that surrounds the combustion chamber hole at an outer position adjacent to the quarter bead.
When the cylinder head gasket is sandwiched between the cylinder head and the cylinder block, the outer edge of the quarter bead and the annular flat portion at the adjacent outer position are in close contact with the cylinder head or the cylinder block, In addition, the inner edge of the quarter bead is firmly attached to the intermediate plate.

  According to the configuration described above, after the cylinder head gasket is sandwiched between the cylinder block and the cylinder head, the combustion gas in the combustion chamber is between the gasket substrates and the intermediate plate and between the gasket substrates and the cylinder head and the cylinder block. Intrusion is prevented. Therefore, it is possible to prevent the rubber coating applied to the surfaces of both gasket substrates from being deteriorated or damaged by the combustion gas, and to provide a cylinder head gasket having a good sealing property and a long life.

The top view of the principal part which shows one Example of this invention. Sectional drawing which follows the II-II line | wire of FIG. Sectional drawing of the principal part which shows 2nd Example of this invention. Sectional drawing of the principal part which shows 3rd Example of this invention. Sectional drawing which shows the principal part of the conventional cylinder head gasket. Sectional drawing of 4th Example of the location corresponding to the VI-VI line of FIG. Sectional drawing of 4th Example of the location corresponding to the VII-VII line of FIG.

The present invention will be described below with reference to the illustrated embodiments. In FIGS. 1 and 2, reference numeral 1 denotes a cylinder head gasket. The cylinder head gasket 1 is sandwiched between a cylinder head 11 and a cylinder block 12. And the seal | sticker between them is maintained by being clamped between both members. The cylinder head gasket 1 according to the present embodiment includes a first gasket substrate 2 that is located on the upper side and abutting on the joining surface 11A of the cylinder head 11, and a first gasket substrate 2 that is located on the lower side and abutting on the joining surface 12A of the cylinder block 12. 2 includes a gasket substrate 3 and an intermediate plate 4 disposed between the gasket substrates 2 and 3 and is formed by laminating them. The gasket substrates 2 and 3 and the intermediate plate 4 constituting the cylinder head gasket 1 are integrally connected at required portions in the laminated state shown in FIG.
The first gasket substrate 2, the second gasket substrate 3, and the intermediate plate 4 are formed in the same shape, and a plurality of combustion chamber holes 2 </ b> A to 4 </ b> A are formed in them according to the positions of the plurality of cylinder bores 12 </ b> B of the cylinder block 12. It is installed. The inner diameters of these combustion chamber holes 2 </ b> A to 4 </ b> A are set to be substantially the same as the inner diameter of the cylinder bore 12 </ b> B of the cylinder block 12. Further, as shown in FIG. 1, a plurality of bolt holes 7 for inserting fastening bolts and cooling water are circulated at required positions of both gasket substrates 2 and 3 and the intermediate plate 4 constituting the cylinder head gasket 1. A water hole 8 for making the oil flow is formed, and an oil hole (not shown) for circulating the lubricating oil is made.

Both the gasket substrates 2 and 3 are made of, for example, SUS301 or SUS304 having a thickness of about 0.2 mm to 0.3 mm, and the intermediate plate 4 is made of SUS301 or SUS304 having a thickness of about 0.08 mm to 0.1 mm. ing.
As shown in FIG. 1, the gasket substrates 2 and 3 and the intermediate plate 4 have shapes that coincide with the joint surfaces 11A and 12A of the cylinder head 11 and the cylinder block 12, respectively, and are formed to have the same plate thickness over the entire area. ing. The intermediate plate 4 is formed flat throughout. On the other hand, full beads 2B and 3B are formed on the gasket substrates 2 and 3 to endlessly surround the combustion chamber holes 2A and 3A. The full bead 2B of the first gasket substrate 2 is formed to bulge upward toward the cylinder head 11, while the full bead 3B of the second gasket substrate 3 bulges downward toward the cylinder block 12. Is formed. That is, the upper and lower full beads 2B and 3B are located symmetrically with respect to the intermediate plate 4, and are formed at positions where they overlap when viewed in the plan view of FIG.

Furthermore, annular flat portions 2D and 3D are formed at the outer positions adjacent to the combustion chamber holes 2A and 3A in the gasket substrates 2 and 3 so as to surround the combustion chamber holes 2A and 3A. Half beads 2C and 3C are formed at the outer position so as to surround the combustion chamber holes 2A and 3A. Further, portions between the half beads 2C and 3C and the full beads 2B and 3B are annular flat portions 2E and 3E surrounding the combustion chamber holes 2A and 3A. The half bead 2C of the first gasket substrate 2 has a cross-sectional shape in which its inner edge rises from the intermediate plate 4A than the outer edge, while the half bead 3C of the second gasket substrate 3 Has a cross-sectional shape in which the inner edge rises from the intermediate plate 4A than the outer edge.
Further, the regions 2F and 3F outside the full beads 2B and 3B in the gasket substrates 2 and 3 are also formed as flat portions.
Further, although not shown in the drawing, the entire surface (upper surface) and back surface (lower surface) of the gasket substrates 2 and 3 and the intermediate plate 4 are covered with a rubber coating made of fluorine or nitrile rubber. Has been. A coating material such as an elastomer material may be used instead of the rubber coating. The reason why the entire areas of both the front and back surfaces of the substrates 2 and 3 and the intermediate plate 4 are covered with the rubber coating is to improve the adhesiveness and the sealing performance with the mating material in the vertical position.

The cylinder head gasket 1 of the present embodiment is configured as described above, and FIG. 2 shows a state before the cylinder head gasket 1 is mounted between the cylinder head 11 and the cylinder block 12. In this state before mounting, the annular flat portions 2D, 2E, 3D, 3E and the regions 2F, 3F are tightened when the cylinder head gasket 1 is fastened to the cylinder head 11 and the cylinder block 12 with fastening bolts. It is maintained in a direction orthogonal to the direction.
As described above, in the cylinder head gasket 1 of the present embodiment, the annular flat portions 2D and 3D are formed at the outer positions adjacent to the combustion chamber holes 2A and 3A in the gasket substrates 2 and 3, and the adjacent outer portions thereof. Half beads 2C and 3C are formed at the positions. In a state before the cylinder head gasket 1 is mounted on the cylinder head 11 and the cylinder block 12, the annular flat portions 2 </ b> D and 3 </ b> D are slightly separated from the intermediate plate 4. Further, the annular flat portions 2E and 3E of the gasket substrates 2 and 3 are in contact with the intermediate plate 3 from above and below, and the regions 2F and 3F outside the full beads 2B and 3B are also in contact with the intermediate plate 3 from above and below. It has become.

The cylinder head gasket 1 configured as described above is mounted between the cylinder block 12 and the cylinder head 11 and is tightened by a fastening bolt (not shown) to be strongly compressed. Then, the first gasket substrate 2 is in close contact with the joining surface 11A of the cylinder head 11, and the second gasket substrate 3 is in close contact with the joining surface 12A of the cylinder block 12.
At that time, in the first gasket substrate 2, the annular flat portion 2 </ b> D rising from the intermediate plate 4 by the half bead 2 </ b> C is in close contact with the joining surface 11 </ b> A of the cylinder head 11, and the top of the full bead 2 </ b> B is also joined to the cylinder head 11. It closely adheres to the surface 11A. In the second gasket substrate 3, the annular flat portion 3 </ b> D rising from the intermediate plate 4 by the half bead 3 </ b> C is firmly attached to the joining surface 12 </ b> A of the cylinder block 12, and the top of the full bead 3 </ b> B is also joined to the joining surface 11 </ b> A of the cylinder head 11. Strongly adheres to. Further, as the upper and lower half beads 2C and 3C are compressed and brought into close contact with the intermediate plate 4 from above and below, the inner edge portion 2D 'of the annular flat portion 2D closely adheres to the upper surface of the intermediate plate 4, The inner edge 3D ′ of the flat portion 3D is in close contact with the lower surface of the intermediate plate 4. Further, the annular flat portions 2E and 3E of the gasket substrates 2 and 3 are also in close contact with the intermediate plate 4 from the vertical position, and the outer regions 2F and 3F are also in close contact with the intermediate plate 4 from the vertical position. Thus, the cylinder head gasket 1 is clamped between the cylinder head 11 and the cylinder block 12 by the fastening bolt.
As described above, since the rubber coating is applied to the entire areas of both the front and back surfaces of the gasket substrates 2 and 3 and the intermediate plate 4, the annular flat portion 2D is formed on the cylinder head 11 after the fastening with the fastening bolt. Adhering to the bonding surface 11A, there is no gap between them. Further, the annular flat portion 3D is in close contact with the joining surface 12A of the cylinder block 12, and no gap is generated between them. Furthermore, the inner edge portions 2D ′ and 3D ′ of the annular flat portions 2D and 3D are also in close contact with the intermediate plate 4 from above and below. Therefore, when the engine is operated, the combustion gas in the combustion chamber holes 2A to 4A is prevented from entering between the annular flat portion 2D and the joint surface 11A of the cylinder head 11, and the annular flat portion. Intrusion between the 3D and the joint surface 12A of the cylinder block 12 is also prevented. Further, the intrusion of the combustion gas between the intermediate plate 4 and the inner edge portions 2D ′ and 3D ′ of the annular flat portions 2D and 3D is also prevented.
Therefore, it is possible to satisfactorily prevent the rubber coating applied to the entire surface of the gasket substrates 2 and 3 and the intermediate plate 4 from being deteriorated or damaged by the combustion gas. Therefore, it is possible to provide a cylinder head gasket having a good sealing property and a long life. The half beads 2C and 3C are formed such that the inner edge portions on the combustion chamber holes 2A and 3A side rise from the intermediate plate 4, so that the annular flat portions 2D and 3D are formed by the elasticity of the half beads 2C and 3C. Followability is provided for the joint surfaces 11A and 12A. For this reason, the inner edges 2D ′ and 3D ′ are maintained in close contact with the upper surface and the lower surface of the intermediate plate 4, so that the combustion gas flows between the bonding surfaces 11A and 12A and the gasket substrates 2 and 3. It is possible to satisfactorily prevent intrusion. Furthermore, since the cylinder head gasket 1 of this embodiment is composed of a total of three gasket substrates including the intermediate plate 4, the configuration is simpler than the conventional products described above, and the overall weight is reduced. And manufacturing cost can be reduced.

FIG. 3 shows a second embodiment of the present invention. In the second embodiment, instead of the annular flat portion 2D (3D) and the half bead 2C (3C) in the first embodiment, FIG. The quarter bead 2G (3G) is formed.
That is, the first gasket substrate 2 is formed with a quarter bead 2G surrounding the combustion chamber hole 2A at an outer position adjacent to the combustion chamber hole 2A, and the second gasket substrate 3 has the combustion chamber hole 3A. A quarter bead 3G is formed so as to surround the combustion chamber hole 3A at an outer position adjacent to each other. The quarter bead 2G of the first gasket substrate 2 is formed such that its inner peripheral edge is close to the intermediate plate 4, that is, close to the second gasket substrate 3. On the other hand, the quarter bead 3G of the second gasket substrate 3 is formed so that its inner peripheral edge is close to the intermediate plate 4, that is, close to the first gasket substrate 2.
Here, the difference in configuration between the quarter bead 2G (3G) and the half beads 2C and 3C in FIG. 2 is as follows. That is, as shown in FIG. 2, the half beads 2C and 3C are configured to have adjacent portions both inside and outside in the radial direction adjacent to the half beads 2C and 3C, while the quarter beads 2G (3G) are configured as shown in FIG. In this configuration, there is an adjacent portion only on one of the inner and outer sides in the radial direction adjacent to it.
An adjacent flat position of the quarter bead 2G in the first gasket substrate 2 surrounds the combustion chamber hole 2A, and an annular flat portion 2E is formed. A full bead 2B similar to that of the embodiment is formed. Further, the region 2F on the outer side of the full bead 2B is formed as a flat portion as in the first embodiment. Further, an annular flat portion 3E is formed in the second gasket substrate 3 adjacent to the quarter bead 3G so as to surround the combustion chamber hole 3A. A full bead 3B similar to that of the first embodiment is formed. The region 3F on the outer side from the full bead 3B is formed as a flat portion as in the first embodiment. Other configurations are the same as those of the first embodiment described above, and the same member numbers are assigned to the members corresponding to the first embodiment.
In the second embodiment, as shown in FIG. 3, the quarter bead of the first gasket substrate 2 is in a state before the cylinder head gasket 1 is mounted and clamped between the cylinder head 11 and the cylinder head gasket 12. The inner peripheral edge of 2G is in contact with the upper surface of the intermediate plate 4, and the annular flat portion 2 </ b> E and a portion on the outer side of the annular flat portion 2 </ b> E are slightly separated from the upper surface of the intermediate plate 4. On the other hand, the inner peripheral edge of the quarter bead 3G of the second gasket substrate 3 is in contact with the lower surface of the intermediate plate 4, and the annular flat portion 3E and a portion on the outer side of the annular flat portion 3E are slightly separated from the lower surface of the intermediate plate 4. It is in a state.
In this state, the cylinder head gasket 1 is mounted between the cylinder head 11 and the cylinder head gasket 12, and these members are fastened by fastening bolts. As described above, since the rubber coating is applied to the entire areas of both the front and back surfaces of the gasket substrates 2 and 3 and the intermediate plate 4, the first gasket substrate 2 is in a state after the fastening by the fastening bolt is completed. The inner peripheral edge of the quarter bead 2G is in close contact with the upper surface of the intermediate plate 4, and the inner peripheral edge of the quarter bead 3G of the second gasket substrate 3 is also in close contact with the lower surface of the intermediate plate 4. Therefore, no gap is generated between the intermediate plate 4 and the quarter beads 2G, 3G.
On the other hand, the quarter bead 2G of the first gasket substrate 2 and the portion on the outer side of the quarter bead are in close contact with the joining surface 11A of the cylinder head 11, so that no gap is generated between them. Further, since the quarter bead 3G of the second gasket substrate 3 and the portion on the outer side of the quarter bead are in close contact with the joint 12A surface of the cylinder block 12, there is no gap between them.
Therefore, intrusion of combustion gas between the first gasket substrate 2 and the joint surface 11A of the cylinder head 11 is prevented, and combustion gas between the second gasket substrate 3 and the joint surface 12A of the cylinder block 12 is prevented. Intrusion is prevented. Further, the intrusion of the combustion gas between the intermediate plate 4 and the quarter beads 2G and 3G of the gasket substrates 2 and 3 is also prevented. Therefore, also in the cylinder head gasket 1 of the second embodiment, it is possible to prevent the rubber coating applied to the entire front and back surfaces of the gasket substrates 2 and 3 and the intermediate plate 4 from being damaged by the combustion gas, and the sealing performance. It is possible to provide the cylinder head gasket 1 having a good life and a long life. Further, the cylinder head gasket 1 of the second embodiment can also realize weight reduction and manufacturing cost reduction as compared with the conventional product.

FIG. 4 shows a third embodiment of the present invention. This third embodiment forms annular flat portions 2H and 3H instead of the full beads 2B and 3B in the second embodiment, and there The first half beads 2J and 3J and the second half beads 2K and 3K are formed at the inner and outer positions adjacent to each other.
That is, quarter gaskets 2G and 3G are formed on both gasket substrates 2 and 3 of the cylinder head gasket 1 at the outer positions adjacent to the combustion chamber holes 2A and 3A, and the annular flat portions 2E and 3E is formed. The configurations of the quarter beads 2G and 3G and the annular flat portions 2E and 3E are the same as those in the second embodiment. And the 1st half bead 2J is formed in the outer position adjacent to the cyclic | annular flat part 2E in the 1st gasket board | substrate 2, the cyclic | annular flat part 2H is formed in the adjoining outer position, and also adjacent to this cyclic | annular flat part 2H. A second half bead 2K is formed at the outward position. The annular flat portion 2H is maintained in a substantially bulged state separated from the intermediate plate 4 by the first half bead 2J and the second half bead 2K. The region 2F on the outer side from the second half bead 2K is a flat portion as in the second embodiment.
Further, a first half bead 3J is formed at an outer position adjacent to the annular flat portion 3E in the second gasket substrate 3, an annular flat portion 3H is formed at an adjacent outer position, and further adjacent to the annular flat portion 3H. A second half bead 3K is formed at the outward position. The annular flat portion 3H is maintained in a substantially bulged state separated from the intermediate plate 4 by the first half beads 3J and the second half beads 3K. The area 3F on the outer side of the second half bead 3K is a flat portion as in the second embodiment.
The quarter beads 2G and the annular flat portion 2E of the first gasket substrate 2 are formed at positions (overlapping positions) that are symmetrical to the quarter beads 3G and the annular flat portion 3E of the second gasket substrate 3 with the intermediate plate 4 interposed therebetween. Yes. Further, the first half bead 2J, the annular flat portion 2H, and the second half bead 2K of the first gasket substrate 2 are also the first half bead 3J, the annular flat portion 3H, and the second half bead 3K of the second gasket substrate 3 with the intermediate plate 4 interposed therebetween. It is formed in the position (position to superpose) which becomes symmetrical. Other configurations are the same as those of the second embodiment, and the same members as those of the second embodiment are denoted by the same member numbers.
Also in the cylinder head gasket 1 of the third embodiment having the above-described configuration, the same operation and effect as the cylinder head gasket 1 of the second embodiment described above can be obtained.

Next, FIGS. 6 to 7 show a fourth embodiment of the present invention. 6 shows a cross-sectional view of the main part of the portion corresponding to the VI-VI line of FIG. 1, and FIG. 7 shows a cross-sectional view of the portion corresponding to the VII-VII line of FIG.
As shown in FIGS. 6 to 7, the fourth embodiment is obtained by changing the configuration of the second gasket substrate 3 in the third embodiment. That is, the second gasket substrate 3 on the lower side has an annular flat portion 3E in a region from the outer position adjacent to the combustion chamber hole 3A to the first half bead 3J. In other words, the part which is the quarter bead 3G in the third embodiment is also configured as the annular flat part 3E. Accordingly, in the fourth embodiment, the radial dimension (dimension in the left-right direction on the drawing) of the annular flat portion 3E is larger than that in the third embodiment. The other configuration is the same as that of the third embodiment shown in FIG. 4, and the corresponding members are denoted by the same reference numerals.
In a state before the cylinder head gasket 1 of the fourth embodiment is sandwiched between the cylinder head 11 and the cylinder block 12, the annular flat portion 3E and the outer region 3F of the second gasket substrate 3 are the lower surface of the intermediate plate 4. It is in a state of touching.
In the cylinder head gasket 1 of the fourth embodiment configured as described above, the cross section of the portion between the adjacent combustion chamber holes 2A (3A, 4A), 2A (3A, 4A) is as shown in FIG. Become. That is, the cross-sectional shape is symmetrical with respect to the center position C of the adjacent left combustion chamber hole 2A (3A, 4A) and right combustion chamber hole 2A (3A, 4A).
When the cylinder head gasket 1 of the fourth embodiment is sandwiched between the cylinder head 11 and the cylinder block 12, the outer edge of the quarter bead 2G of the first gasket substrate 2 and its adjacent outer side The annular flat portion 2E at the position is in close contact with the joining surface 11A of the cylinder head 11, and the inner edge of the quarter bead 2G is in close contact with the upper surface of the intermediate plate 4. The annular flat portion 3E of the second gasket substrate 3 is in close contact with the joining surface 12A of the cylinder block 12 and the lower surface of the intermediate plate 4, and the outer annular flat portion 3H is also in close contact with the joining surface 12A of the cylinder block. . Therefore, also in the cylinder head gasket 1 of the fourth embodiment, the same operation and effect as in the third embodiment described above can be obtained.
In the fourth embodiment shown in FIGS. 6 to 7, the annular flat portion 3E is formed at the outer position adjacent to the combustion chamber hole 2A (3A, 4A) in the second gasket substrate 3 on the lower side. However, a configuration in which the cross-sectional shapes of the first gasket substrate 2 and the second gasket substrate 3 are reversed across the intermediate plate 4 may be employed. That is, in the said 3rd Example, the location of the quarter bead part 2G in the 1st gasket board | substrate 2 is also formed as the cyclic | annular flat part 2E, and another part is good also as the same structure as 3rd Example. Even with such a configuration, the same operations and effects as in the fourth embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Cylinder head gasket 2 ... 1st gasket board | substrate 2A ... Combustion chamber hole 2C ... Half bead 2D ... Annular flat part 3 ... 2nd gasket board | substrate 3A ... Combustion chamber hole 3C ... Half bead 3D ... Annular flat part 4 ... Intermediate plate 11 ... Cylinder Head 12 Cylinder block

Claims (6)

The first gasket substrate in a laminated state, comprising an upper first gasket substrate, a lower second gasket substrate, and an intermediate plate provided between the first gasket substrate and the second gasket substrate. In the cylinder head gasket in which the combustion chamber hole is formed at a predetermined position of the second gasket substrate and the intermediate plate,
The first gasket substrate includes an annular flat portion surrounding the combustion chamber hole at an outer position adjacent to the combustion chamber hole, and surrounds the combustion chamber hole at an outer position adjacent to the annular flat portion. And the inner edge has a herb bead that rises from the intermediate plate than the outer edge,
The second gasket substrate includes an annular flat portion surrounding the combustion chamber hole at an outer position adjacent to the combustion chamber hole, surrounds the combustion chamber hole at an outer position adjacent to the annular flat portion, and The inner edge has a half bead that rises from the intermediate plate than the outer edge,
When the cylinder head gasket is sandwiched between the cylinder head and the cylinder block, the annular flat portion of the first gasket substrate is in close contact with the cylinder head and the annular flat portion of the second gasket substrate is in close contact with the cylinder block, Furthermore, the inner edge of the annular flat portions of the two gasket substrates is firmly attached to the intermediate plate from above and below. The first gasket substrate in a laminated state, comprising an upper first gasket substrate, a lower second gasket substrate, and an intermediate plate provided between the first gasket substrate and the second gasket substrate. In the cylinder head gasket in which the combustion chamber hole is formed at a predetermined position of the second gasket substrate and the intermediate plate,
At least one of the first gasket substrate and the second gasket substrate surrounds the combustion chamber hole at an outer position adjacent to the combustion chamber hole, and an outer edge portion is closer to an inner edge portion. Also includes a quarter bead that rises from the intermediate plate, and an annular flat portion that surrounds the combustion chamber hole at an outer position adjacent to the quarter bead.
When the cylinder head gasket is sandwiched between the cylinder head and the cylinder block, the outer edge of the quarter bead and the annular flat portion at the adjacent outer position are in close contact with the cylinder head or the cylinder block, The cylinder head gasket is characterized in that an inner edge of the quarter bead is firmly attached to the intermediate plate. The first gasket substrate has a quarter bead that surrounds the combustion chamber hole at an outer position adjacent to the combustion chamber hole, and an outer edge rises from an intermediate plate than an inner edge. And an annular flat portion surrounding the combustion chamber hole at an outer position adjacent to the quarter bead,
The second gasket substrate has a quarter bead that surrounds the combustion chamber hole at an outer position adjacent to the combustion chamber hole, and an outer edge rises from an intermediate plate than an inner edge. And an annular flat portion surrounding the combustion chamber hole at an outer position adjacent to the quarter bead,
When the cylinder head gasket is sandwiched between the cylinder head and the cylinder block, the outer edge of the quarter bead of the first gasket substrate and the annular flat portion at the adjacent outer position are in close contact with the cylinder head. ,
The outer edge of the quarter bead of the second gasket substrate and the annular flat portion at the adjacent outer position are in close contact with the cylinder block,
The inner edge of the quarter bead of the first gasket substrate and the inner edge of the quarter bead of the second gasket substrate are in close contact with the intermediate plate from above and below. Cylinder head gasket as described. A full bead that surrounds the combustion chamber hole and bulges toward the cylinder head is formed at an outer position adjacent to the annular flat portion of the first gasket substrate.
4. A full bead that surrounds the combustion chamber hole and bulges toward the cylinder block is formed at an outer position adjacent to the annular flat portion of the second gasket substrate. Cylinder head gasket as described. In the first gasket substrate, a first half bead, a second annular flat portion and a second half bead are sequentially formed adjacent to the outer position of the annular flat portion and surrounding the combustion chamber hole,
In the second gasket substrate, a first half bead, a second annular flat portion, and a second half bead are sequentially formed adjacent to the outer position of the annular flat portion and surrounding the combustion chamber hole. The cylinder head gasket according to claim 3. The first gasket substrate has a quarter bead that surrounds the combustion chamber hole at an outer position adjacent to the combustion chamber hole, and an outer edge rises from an intermediate plate than an inner edge. And an annular flat portion surrounding the combustion chamber hole at an outer position adjacent to the quarter bead,
The second gasket substrate includes an annular flat portion surrounding the combustion chamber hole at an outer position adjacent to the combustion chamber hole,
When the cylinder head gasket is sandwiched between the cylinder head and the cylinder block,
The outer edge of the quarter bead of the first gasket substrate and the annular flat portion adjacent to the outer periphery thereof are in close contact with the cylinder head, and the inner edge of the quarter bead is the upper surface of the intermediate plate. Strongly adhere to,
The cylinder head gasket according to claim 2, wherein the annular flat portion of the second gasket substrate is in close contact with the lower surface of the cylinder block and the intermediate plate.

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