JP2003083165A - Cylinder head gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head gasket 1 having superior sealability and capable of being inexpensively manufactured. SOLUTION: This cylinder head gasket is composed of a foundation plate 11 made of an aluminum material and having plural bores 11a corresponding to a combustion chamber, and bore seals 12 made of a rubber elastic material and mounted around bores 11a of the foundation plate 11. The bore seals 12 are fitted in grooves 111U, 111L formed along the circumference of the bores 11a on both faces of the foundation plate 11, seal lips 121U, 121L are projected to the thickness direction of the foundation plate 11, and running-off deformation permitting spaces S1 in compressing the bore seals 12 are formed respectively between the seal lip 121U, 121L and the groove 111U, 111L. The seal lips 121U, 121L get good results in self-sealing function by the combustion gas pressure in the combustion chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head gasket interposed between opposed surfaces of a cylinder head and a cylinder block in a gasoline engine or the like.

[0002]

2. Description of the Related Art In an internal combustion engine, for example, a multi-cylinder gasoline engine, a cylinder head gasket is interposed between opposed surfaces of a cylinder block and a cylinder head. FIG. 9 is an explanatory view schematically showing a cylinder head gasket according to a conventional technique, that is, FIG.
The cylinder head gasket 100 shown in (C) is
For example, it is made of a metal plate having appropriate elasticity such as a thin stainless spring steel plate coated with a thin synthetic rubber layer on the surface thereof. Each combustion chamber 110a of the cylinder block 110, a plurality of bores 101 corresponding to each of them, and an oil passage A plurality of openings (not shown) corresponding to the oil holes and the cooling water holes for passing engine cooling water are opened, and the sealing beads 102 are provided around the bore 101 and along each opening. It has a formed structure. Further, the cylinder block 110 and the cylinder head 12 are provided on the inner peripheral side of the bead 102.
A stopper 103 is provided around the bead 102 in order to limit the amount of the bead 102 crushed between the facing surfaces of 0 and to obtain a predetermined surface pressure by crushing the bead 102.

[0003]

Some cylinder head gaskets 100 of this type are made of a single metal plate as shown in FIG. 9A. In this case, the combustion chamber 110a is used.
Cylinder head 12 in response to combustion gas pressure during combustion in
When 0 vibrates up and down, the bead 102 is also deformed following it, and therefore metal fatigue may occur if the displacement due to vibration is large. Therefore, in order to prevent such metal fatigue from occurring, it is necessary to stack a plurality of metal plates to reduce the displacement amount per one as shown in FIGS. 9B and 9C, which results in high cost. It was. Also,
As shown in FIG. 9A, in the case of a single metal plate, the stopper 103 must be attached by welding or the like, resulting in high cost.

In recent years, in gasoline engines, the cylinder block 110 and the cylinder head 120 are often made of aluminum. In such a case, when the tightening force of the cylinder head gasket 100 is increased in order to obtain a high surface pressure. In addition, the cylinder block 110 and the cylinder head 120 may be excessively deformed in the bore and the cam journal, and may be set by the tightening force, or the contact surface with the cylinder head gasket 100 may be damaged. Further, the cylinder head gasket 100 is made of stainless spring steel plate to give the bead 102 a required elasticity. However, the stainless spring steel plate is expensive, and the cylinder block 110 and the cylinder head made of aluminum are used. 12
Due to the difference in the coefficient of linear expansion from 0, the bore 10 is different from the cylinder block 110 and the cylinder head 120.
1 may cause friction in the direction perpendicular to the shaft center of No. 1 and cause wear or damage.

When the cylinder head gasket 100 is manufactured by punching and pressing a pre-coated material in which a surface of a stainless spring steel plate or the like is coated with a synthetic rubber layer in advance, the synthetic waste rubber layer adheres to the press waste material. It is difficult to recycle waste press materials. On the other hand, in the aftercoating in which the synthetic rubber layer is applied after the metal plate is punched and pressed, when a coating method such as a flow coater or a spray is adopted, the yield of the synthetic rubber is low, and the applied synthetic rubber is the bore 101. When the coating method by screen printing is adopted because a part with a large layer thickness of the synthetic rubber layer is created by lining around at the outer edge part and
It is necessary to apply the unvulcanized rubber material on one surface and dry it, and then apply it to the back surface and dry it before vulcanizing, which is a complicated process.

Further, at the three-face mating portion between the cylinder block 110 and the cylinder head 120 and the chain case (not shown), the cylinder block 110, the cylinder head 120,
Since a step is generated between the chain case and the cylinder head gasket 100, it is difficult to seal this portion. Therefore, conventionally, at the time of engine assembly, a portion of the outer peripheral portion of the cylinder head gasket 100, which corresponds to the three-sided mating portion, is made of normal temperature curable silicone rubber or the like.
IPG (Formed-in-Place Gasket) is applied. F
IPG, which is also called a liquid packing, has a sealing function by being applied in a liquid state and then crosslinked and cured at room temperature to form a rubber-like elastic body.
Due to the need for PG application work, engine assembly work has become complicated.

The present invention has been made in view of the above problems, and a technical problem thereof is to provide a cylinder head gasket which is excellent in sealing property and can be produced at low cost. .

[0008]

The conventional technical problems can be effectively solved by the present invention. That is, the cylinder head gasket according to the invention of claim 1 is interposed between the opposing surfaces of the cylinder block and the cylinder head of the internal combustion engine, and comprises a plurality of combustion chambers of the cylinder block and the cylinder head. It is composed of a metal substrate having a bore formed therein, and a bore seal made of a rubber-like elastic material and continuously provided around the bore of the substrate.

According to a second aspect of the present invention, in the cylinder head gasket according to the first aspect, the substrate is made of an aluminum material. The aluminum material here includes aluminum and aluminum alloys.

In the cylinder head gasket according to a third aspect of the present invention, in the structure according to the first or second aspect, the bore seal is formed in a groove formed along both sides of the substrate along the circumference of the bore, and the tip thereof is formed. The seal lip protrudes in the thickness direction of the substrate, and an escape deformation allowance space at the time of compression of the bore seal is formed between the seal lip and the inner side surface of the groove.

The cylinder head gasket according to a fourth aspect of the present invention is the cylinder head gasket according to any one of the first to third aspects, wherein the cylinder block and the end portion of the base plate corresponding to the mating portion of the cylinder head and the chain case, A second seal made of a rubber-like elastic material that is in close contact with the cylinder block, the cylinder head and the chain case is provided.

In a cylinder head gasket according to a fifth aspect of the present invention, in the structure according to any one of the first to fourth aspects, an oil hole for letting lubricating oil and a water hole for letting cooling water pass are formed in the substrate. The substrate is provided with an oil hole seal made of a rubber-like elastic material provided around the oil hole and a water hole seal made of a rubber-like elastic material provided around the water hole.

[0013]

1 is a schematic plan view showing a preferred embodiment of a cylinder head gasket according to the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG.
FIG. 3 is a cross-sectional view taken along a line corresponding to the line II-II in FIG. 1, showing a state in which the cylinder block and the cylinder head of the internal combustion engine are mounted, and FIG. 4 is a cylinder block, a cylinder head and a chain case. It is explanatory drawing which shows the relationship between a cylinder head gasket.

As shown in FIG. 1, a cylinder head gasket 1 according to the present invention includes a substrate 11 made of a thin aluminum plate, a bore seal 12 integrally formed on the substrate 11, and made of a rubber-like elastic material. The second seal 13, the oil hole seal 14, and the water hole seal 15 are provided, and as shown in FIG. 4, a cylinder block 2, a cylinder head 3, and a chain case 5 in a gasoline engine or the like.
It is something that is interposed between and.

As shown in FIG. 1, the substrate 11 has a plurality of bores 11a corresponding to the combustion chamber 4 formed from the cylinder block 2 to the inner surface of the cylinder head 3, and the cylinder head 3 and the cylinder block 2. Plural bolt holes 11b for inserting tightly tightened bolts, oil holes 11c for passing lubricating oil, and water holes 11d for passing engine cooling water to a water jacket (not shown) provided around the cylinder block 2 Has been established.
The illustrated example is for four cylinders, and therefore, the bores 11a are formed corresponding to the four combustion chambers 4, respectively.

The bore seal 12 prevents the combustion gas in the combustion chamber 4 from leaking between the cylinder block 2 and the cylinder head 3, and is provided around each bore 11a. Specifically, as shown in FIG. 2, the substrate 1
Circumferentially continuous grooves 111U and 111L are formed on the upper and lower surfaces of 1 along the circumference of each bore 11a.
The bore seal 12 is provided in the grooves 111U and 111L and is made of silicone rubber, fluororubber or heat resistant N.
Seal lips 121U, 121L formed of a rubber-like elastic material having heat resistance and oil resistance, such as BR, and formed symmetrically with respect to the thickness direction of the substrate 11 are provided in the grooves 111U, 111L. It projects from the upper and lower surfaces of 11 to the outside.

Grooves 111U, 111 on both upper and lower surfaces of the substrate 11
Communication holes 112 pass through between L at predetermined intervals in the circumferential direction of the grooves 111U and 111L, and the bore seal 12 is
The seal lips 121U and 121L are the communication holes 112.
They are formed continuously with each other through the bridge portion 122 formed inside. That is, the communication hole 112 is formed in the grooves 111U and 11U of the substrate 11 when the bore seal 12 is vulcanized.
It is formed so that the molding rubber material filled in one of the 1 L is poured into the other groove. In addition, as described above, the upper and lower seal lips 121U and 121L are
They are continuous with each other via the bridging portion 122, which allows the groove 1
Since it is constrained to 11U and 111L, it is not necessary to bond it to the groove bottom surface.

The communication hole 112 is located at a position closer to the inner circumference on the bottom surface of the grooves 111U and 111L, more specifically, the bore seal 12.
The seal lips 121U, 121L are provided at a plurality of positions at positions inside the tops of the seal lips 121U, 121L at appropriate intervals in the circumferential direction of the grooves 111U, 111L. In addition, the groove 111U,
Between the inner side surfaces 111a and 111b of the 111L and the seal lips 121U and 121L, there is an escape deformation allowable space S1.

By the way, as shown in FIG. 4, the cylinder block 2, the cylinder head 3, and the chain case 5 are
There are two types of three-sided mating parts. That is, FIG.
As shown in (A) of FIG. 3A, the chain case 5 is attached to the outer surfaces of both the cylinder block 2 and the cylinder head 3, and as shown in FIG. Chain case 5
Of the cylinder head gasket 1, and the end shape of the cylinder head gasket 1 is formed corresponding to the form of (A) or (B).

FIG. 5 is a plan view showing the end shape of the cylinder head gasket 1 corresponding to the three-face mating portion X of the cylinder block 2, the cylinder head 3 and the chain case 5 shown in FIG. A) is A in FIG.
A cross-sectional view taken along line -A, and FIG. 6B is a cross-sectional view taken along line BB in FIG.

That is, in the case of the three-faced mating portion X having the form shown in FIG. 4 (A), the cylinder head gasket 1 is interposed between the cylinder block 2 and the cylinder head 3 and at one end thereof. 1a is located at the three-sided mating portion X and faces the inner side surface of the chain case 5. Specifically, the chain case 5 is formed with a space (not shown) that serves as a passage for the chain for transmitting the driving force of the crankshaft to the camshaft to drive the valve. As shown in FIGS. 1 and 5, a notch 11e corresponding to the above-mentioned chain passage space is formed at one end of the, and the tips of the overhanging portions 11f on both sides of the notch 11e are formed on the three-sided mating portion X.
Is located in. The second seal 13 is provided at the tip of this overhanging portion 11f.

The substrate 11 has grooves 113U and 113L having a sectional shape as shown in FIG. 6 continuously formed on both upper and lower surfaces of the substrate 11 from the notch 11e to the tips of the overhanging portions 11f. The second seal 13 has a groove 113U,
It is provided in 113L. Also, the grooves 113U and 113
In the portion located at the three-sided mating portion X, L is shown in FIG.
As shown in FIG. 6, the L-shaped cross section is open to the tip of the overhanging portion 11f of the substrate 11, and the other portion, that is, the portion extending along the notch 11e is as shown in FIG. 6B. , It has a shallow U-shaped cross section.

Lubricating oil is supplied to the chain running in the chain passage space in the chain case 5, and the second seal 13 seals the lubricating oil to seal the chain passage space. , Cylinder block 2,
The cylinder head 3 and the chain case 5 are sealed at the three-face mating portion X. This second seal 13
Is formed of a rubber-like elastic material and surrounds the tip of the overhanging portion 11f of the substrate 11, as shown in FIG. The three-sided seal portion 131 is formed, and the other portion, that is, the portion extending along the notch 11e is shown in FIG.
As shown in (B), the substrate 11 protrudes from inside the grooves 113U and 113L to the outside from the upper and lower surfaces of the substrate 11 and
The seal lips 132U and 132L are formed symmetrically to each other in the thickness direction. Also, the grooves 113U, 1
Between the inner side surfaces of 13L and the seal lips 132U and 132L, there is an escape deformation allowable space S2.

This groove 113 is provided between the grooves 113U and 113L.
The bottom surfaces of the U and 113L communicate with each other through a plurality of communication holes 114 that are provided at appropriate intervals in the extension direction, and the second seal 13 has a communication hole 11 between the grooves 113U and 113L on both sides.
4 are bridged to each other via a bridging portion 133 formed in the inside. That is, the communication holes 114 are formed in the grooves 113U and 11U of the substrate 11 when the second seal 13 is vulcanized.
The second seal 13 is formed for pouring the molding rubber material filled in one of the 3L into the other groove.
Is constrained to the grooves 113U and 113L by the bridging portion 133, so that it is not particularly necessary to adhere to the groove bottom surface.

Next, FIG. 7 shows an end shape of the cylinder head gasket 1 corresponding to the three-faced mating portion Y shown in FIG. 4B. (A) is a plan view and (B) is a bottom view. ,
8A is a cross-sectional view taken along line AA in FIG. 7A, and FIG. 8B is a cross-sectional view taken along line BB in FIG. 7B.

That is, in the case of the three-sided mating portion Y having the form as shown in FIG. 4B, the cylinder head gasket 1 includes the cylinder block 2 and the chain case 5.
And a cylinder head 3 mounted over the upper surfaces of both of them, a portion of the chain 1 that is located on the upper surface of the chain case 5 has a substrate 11 as shown in FIG.
An opening 11g corresponding to the chain passage space formed in the chain case 5 is opened. The second seal 13 is continuously provided in an annular shape on the upper and lower surfaces of the substrate 11 along the periphery of the opening 11g. The second seal 13 has a different shape between the upper surface side of the cylinder head gasket 1 shown in FIG. 7A and the lower surface side of the cylinder head gasket 1 shown in FIG. 7B, that is, On the upper surface side, the entire circumference is formed to have a uniform width, whereas on the lower surface side, the portion located at the three-sided mating portion Y is formed wide.

More specifically, the board 11 is provided along the circumference of the chain passage opening 11g on both upper and lower surfaces thereof as shown in FIG.
The grooves 115U and 115L each having a U-shaped cross section are continuously formed in an annular shape as shown in FIG. 1, and the annular second seal 13 for ensuring the hermeticity in the chain passage is the groove 1
It is provided in 15U and 115L. The second seal 13 is formed of a rubber-like elastic material, and as shown in FIG. 8, projects from the inside of the grooves 115U and 115L to the outside from the upper and lower surfaces of the substrate 11 and in the thickness direction of the substrate 11. Seal lips 132 formed symmetrically with respect to each other
U and 132L are provided, and an escape deformation allowance space S3 is formed between both inner side surfaces of the grooves 115U and 115L and the seal lips 132U and 132L.

At the position of the three-sided mating portion Y (two positions in the circumferential direction), as shown in FIG. 8B, the groove 115L on the lower surface side is formed.
Is formed to be wider than the groove 115U on the upper surface side, and the seal lip 132L on the lower surface side is correspondingly formed.
Is also formed in a flat shape that is wider than the seal lip 132U on the upper surface side, and this wide portion is the upper surface of the cylinder block 2 and the chain case 5 shown in FIG. 4 (B).
It is designed to be closely contacted over the upper surface of the.

Between the grooves 115U and 115L, the groove 115
The bottom surfaces of the U and 115L communicate with each other through a plurality of communication holes 116 formed at appropriate intervals in the extension direction, and the second seal 13 is formed in the communication hole 116 between the grooves 115 and 115 on both sides. They are bridged to each other via the bridge portion 134. That is, the communication holes 116 are formed in the grooves 115U and 115L in the substrate 11 when the second seal 13 is vulcanized.
The second seal 13 is formed for pouring the molding rubber material filled in one of the two into the other groove.
Since the bridge portion 134 restrains the grooves 115U and 115L, it is not necessary to bond them to the bottom surface of the groove.

The oil hole seal 14 shown in FIG.
The lubricating oil that passes through the oil hole 11c is the cylinder block 2
It is to prevent leakage from between the cylinder head 3 and the cylinder head 3, and is provided around each oil hole 11c. Its sectional shape is similar to that of the bore seal 12 shown in FIG. 2, that is, the grooves on both sides of the substrate 11 are molded with a rubber-like elastic material and have symmetrical seal lips.

In the water hole seal 15 shown in FIG. 1, the engine cooling water passing through the water hole 11d is prevented from flowing into the cylinder block 2.
It prevents leakage from between the cylinder head 3 and the cylinder head 3, and is provided so as to comprehensively surround the outer peripheral side of each bore seal 12. Its sectional shape is similar to that of the bore seal 12 shown in FIG. 2, that is, the grooves on both sides of the substrate 11 are molded with a rubber-like elastic material and have symmetrical seal lips. The water holes 11d are located between the bore seals 12 and the water hole seals 15 and are opened in the substrate 11, that is, the engine cooling water passing through the water holes 11d is on the inner peripheral side (bore 11a side). To the outer peripheral side is blocked by the water hole seal 15.

The cylinder head gasket 1 constructed as described above is a substrate 11 obtained by punching and pressing an aluminum plate.
Can be manufactured by molding the bore seal 12, the second seal 13, the oil hole seal 14 and the water hole seal 15 made of a rubber-like elastic material at a time, and the second seal 13 and the oil hole Since the seal 14 and the water hole seal 15 do not require heat resistance unlike the bore seal 12, a rubber material cheaper than NBR or the like can be used, and therefore the manufacturing cost can be reduced. Moreover, this cylinder head gasket 1 is shown in FIG.
Since it is used as a single piece as shown in Fig. 2, it is not necessary to stack multiple pieces to relieve the stress of the bead unlike the conventional cylinder head gasket that seals with a metal bead, so it is inexpensive. Can be provided to.

Further, since it is not necessary to coat the surface of the aluminum plate for manufacturing the substrate 11 with a synthetic rubber layer or the like, the end material of the aluminum plate produced by punching is
It can be recycled.

The cylinder head gasket 1 is formed by the bolts inserted into the respective bolt holes 11b shown in FIG.
A pressure is applied between the cylinder block 2 and the cylinder head 3. Therefore, in the unattached state, as shown in FIG. 2, the seal lip 1 of each of the bore seals 12 protruding from the inside of the grooves 111U and 111L to the outside from the upper and lower surfaces of the substrate 11.
21U and 121L are compressed from both sides in the thickness direction of the substrate 11 as shown in FIG. 3, and by the reaction force thereof, the upper surface 2a of the cylinder block 2 and the lower surface 3 of the cylinder head 3 are compressed.
Pressed against a. Further, the groove 11 shown in FIG. 6 or FIG.
Substrate 11 from within 3U, 113L or 115U, 115L
Similarly, the respective seal lips 132U and 132L of the second seal 13 and the seal lips of the oil hole seal 14 and the water hole seal 15 that have protruded to the outside from the surface height of
The substrate 11 is compressed from both sides in the thickness direction, and its reaction force presses the upper surface of the cylinder block 2 and the lower surface of the cylinder head 3.

In FIG. 3, the distribution of the contact surface pressure of the bore seal 12 on the upper surface 2a and the lower surface 3a of the cylinder block 2 and the cylinder head 3 is shown by a large number of arrows. That is, since the crushing amount due to compression is the largest at the portions corresponding to the tops of the seal lips 121U and 121L of the bore seal 12 in the unattached state, the bore seal 12
The contact surface pressure of is the largest in this part. Then, in the grooves 111U, 111L, the seal lips 121U, 121L are deformed in the lateral direction (radial direction of the bore seal 12) toward the escape spaces on both sides thereof due to the compressive stress.
A wide sealing surface is formed.

Further, the pressure P of the combustion gas generated in the combustion chamber 4 is the gap G between the substrate 11 and the cylinder block 2 and the cylinder head 3 through the bore seal 12 and the groove 111U.
It acts so as to press against the inner surface 111b on the outer peripheral side in 111L, and the reaction force thereby acts so as to press the bore seal 12 against the upper surface 2a of the cylinder block 2 and the lower surface 3a of the cylinder head 3. Therefore, it has a self-sealing function in which the seal surface pressure changes according to the pressure P.

Further, the communication hole 112 for turning the rubber material for molding at the time of molding the bore seal 12 is formed so as to be located on the inner peripheral side (bore 11a side) of the region where the contact surface pressure becomes large. Moreover, since the bore seal 12 is unevenly distributed to the outer peripheral side in the grooves 111U and 111L in response to the pressure P of the combustion gas, there is no portion where the contact surface pressure is insufficient due to the existence of the communication hole 112.

Therefore, the bore seal 12 is provided in the combustion chamber 4
It exhibits excellent sealing properties against high temperature and high pressure combustion gas generated inside. Moreover, the cylinder block 2 and the cylinder head 3 have the self-sealing function of converting the pressure P of the combustion gas into the pressing force to the upper surface 2a and the lower surface 3a of the cylinder block 2 and the cylinder head 3.
The tightening load between and does not have to be as great as when sealing is done by crushing the metal beads. In addition, since the bore seal 12 is made of a rubber-like elastic material, the deformation due to the vertical vibration of the cylinder head 3 does not cause fatigue, and the upper surface 2a and the lower surface 3a of the cylinder head 3 and the cylinder block 2 are not distorted. Can also be effectively absorbed.

On the other hand, in the case of the form shown in FIGS. 5 and 6, the second seal 13 is located at the three-face mating portion X of the cylinder block 2, the cylinder head 3 and the chain case 5 shown in FIG. 4 (A). The upper surface 131a of the three-sided sealing portion 131 shown in FIG. 6A is in close contact with the lower surface of the end of the cylinder head 3, and the lower surface 131b of the three-sided sealing portion 131.
Is brought into close contact with the upper surface of the end portion of the cylinder block 2, and the end surface 131c of the three-face seal portion 131 is brought into close contact with the inner side surface of the chain case 5. In the case of the configuration shown in FIGS. 7 and 8, the upper seal lip 1 shown in FIG.
32U is brought into close contact with a portion of the lower surface of the cylinder head 3 around the chain passage space, and the lower seal lip 1
32L is brought into close contact with the peripheral portions of the chain passage space on the upper surfaces of the cylinder block 2 and the chain case 5. Moreover, as shown in FIG. 8B, a wide lower seal lip 132L is brought into close contact with the boundary position between the upper surface of the cylinder block 2 and the upper surface of the chain case 5.

Therefore, the three-sided mating portion Y with the cylinder block 2, the cylinder head 3 and the chain case 5 can be well sealed, and there is no need to seal the three-sided mating portion by coating with FIPG or the like as in the conventional case. .

Oil hole seal 14 and water hole seal 1
Since 5 also has the same structure as the bore seal 12, the seal lip exerts a self-sealing action by the pressure of the lubricating oil passing through the oil hole 11c or the pressure of the engine cooling water passing through the water hole 11d. And has excellent sealing properties.

The present invention is not limited to the illustrated embodiment, and for example, the seal lips 121U and 121L of the bore seal 12 and the seal lips 132U and 132L of the second seal 13 are formed in a chevron shape. It is possible to make various changes such as Also, the bore seal 12, the second seal 13, the oil hole seal 1
4 and the water hole seal 15 may be integrally bonded to the substrate 11 at the time of molding.

[0043]

According to the cylinder head gasket of the first aspect of the present invention, since the bore seal made of the rubber-like elastic material is continuously formed around the bore formed in the substrate, the cylinder head gasket It is possible to prevent breakage of the seal portion due to vibration, and it is not necessary to stack a plurality of cylinder heads in consideration of the amplitude of the cylinder head. Further, since it is not necessary to cover the surface of the substrate with a thin synthetic rubber layer, the structure is simple and the device can be provided at low cost. In addition, since the thin synthetic rubber layer is not applied to the surface of the metal plate serving as the substrate, the scraps generated by punching the metal plate when manufacturing the substrate can be recycled.

Further, since the bore seal is made of a rubber-like elastic material, the tightening force for the cylinder head gasket can be remarkably reduced as compared with the conventional case where the metal beads are crushed and sealed, and as a result, the cylinder block. It is possible to prevent distortion and fatigue of the cylinder head.

According to the cylinder head gasket of the second aspect of the invention, since the substrate is made of an aluminum material, friction does not occur due to the difference in linear expansion coefficient between the cylinder block and the cylinder head made of aluminum, and The sealability is not impaired.

According to the cylinder head gasket of the third aspect of the present invention, since the bore seals are provided in the grooves formed along both sides of the substrate along the circumference of the bore, the pressure of the combustion gas is kept in the cylinder block and the cylinder. Due to the self-sealing function that converts it into a pressing force against the head, it is possible to exhibit excellent sealing performance with a small tightening load.

According to the cylinder head gasket of the fourth aspect of the present invention, the cylinder block and the three-face mating portion of the cylinder head and the chain case are sealed by the second seal provided at the end portion of the substrate, so that the FIP.
By applying G or the like, it is not necessary to seal this portion, and the complexity at the time of assembly can be eliminated. Further, since the second seal does not require heat resistance, an inexpensive rubber-like elastic material can be used, and the second seal can be formed at the same time when forming the bore seal, so that the cylinder head gasket can be provided at low cost. be able to.

According to the cylinder head gasket of the fifth aspect of the invention, there is also provided an oil hole seal for preventing leakage of lubricating oil through the oil hole and a water hole seal for preventing leakage of cooling water through the water hole. , Made of rubber-like elastic material,
It is possible to prevent the damage of the seal part due to the vibration of the cylinder head, and it is possible to significantly reduce the tightening force on the cylinder head gasket compared to the conventional case where the metal beads are crushed and sealed, and as a result, the cylinder It is possible to prevent distortion and settling of blocks and cylinder heads. Further, since the oil hole seal and the water hole seal do not require heat resistance, an inexpensive rubber-like elastic material can be used, and they can be molded at the same time when the bore seal is molded. Can be provided at low cost.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a preferred embodiment of a cylinder head gasket according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a view showing a state where the engine is mounted between a cylinder block and a cylinder head of the internal combustion engine in the above embodiment.
FIG. 3 is a cross-sectional view taken along line II-II in FIG.

FIG. 4 is an explanatory diagram showing a relationship between a cylinder block, a cylinder head, a chain case, and a cylinder head gasket.

5 is a plan view showing an end shape of a cylinder head gasket corresponding to the three-faced mating portion shown in FIG. 4 (A).

6 shows a second seal, (A) is a cross-sectional view taken along the line AA in FIG. 5, (B) is a B in FIG.
It is sectional drawing cut | disconnected by the -B line.

FIG. 7 is a view showing an end shape of a cylinder head gasket corresponding to the three-sided mating portion shown in FIG. 4 (B).
(A) is a plan view and (B) is a bottom view.

8 shows a second seal, (A) is a cross-sectional view taken along the line AA in FIG. 7, (B) is a B in FIG.
It is sectional drawing cut | disconnected by the -B line.

FIG. 9 is an explanatory view schematically showing a cylinder head gasket according to a conventional technique.

[Explanation of symbols]

1 Cylinder Head Gasket 11 Substrate 11a Bore 111U, 111L, 113U, 113L, 115U,
115L Groove 112, 114, 116 Communication hole 12 Bore seal 121U, 121L, 132U, 132L Seal lip 122, 133, 134 Bridge part 13 Second seal 131 Three-sided seal part 14 Oil hole seal 15 Water hole seal 2 Cylinder block 2a Upper surface 3 Cylinder head 3a Lower surface 4 Combustion chamber 5 Chain case S1, S2, S3 Relief deformation allowable space X, Y

Claims (5)

[Claims] 1. A cylinder head gasket (1) interposed between opposed surfaces of a cylinder block (2) and a cylinder head (3) of an internal combustion engine, each of the cylinder block (2) and the cylinder head (3). A metallic substrate (11) having a plurality of bores (11a) corresponding to the combustion chamber (4), and the bore (1) in the substrate (11).
A cylinder head gasket, comprising a bore seal (12) made of a rubber-like elastic material and continuously provided around the periphery of 1a). 2. The cylinder head gasket according to claim 1, wherein the substrate (11) is made of an aluminum material. 3. A groove (11) formed with bore seals (12) on both sides of the substrate (11) along the perimeter of the bore (11a).
1U, 111L), the seal lip (121U, 121L) at the tip projects in the thickness direction of the substrate (11), and the seal lip (121U, 121L)
And the inner surface of the groove (111U, 111L) between the bore seal (12) at the time of compression deformation relief allowable space (S
The cylinder head gasket according to claim 1 or 2, wherein 1) is formed. 4. The cylinder block (2), the cylinder head (3) and the chain case (5) corresponding to the three-sided mating portion (X, Y) of the cylinder block (2) at the end of the substrate (11). 2. A second seal (13) made of a rubber-like elastic material, which is in close contact with the cylinder head (3) and the chain case (5), is provided.
The cylinder head gasket according to any one of 1 to 3. 5. A substrate (11) is provided with an oil hole (11c) through which lubricating oil passes and a water hole (11d) through which cooling water passes, and the substrate (11) is provided around the oil hole (11c). An oil hole seal (14) made of a rubber-like elastic material and a water hole seal (15) made of a rubber-like elastic material provided around the water hole (11d) are provided. The cylinder head gasket according to any one of claims 1 to 4.