JP6115710B2 - Cylinder head gasket - Google Patents

Description

  The present invention relates to a cylinder head gasket, and more particularly to a cylinder head gasket provided with a combustion chamber hole bead that surrounds the combustion chamber hole endlessly and a water hole bead that surrounds the water hole.

Conventionally, as a cylinder head gasket, a gasket substrate sandwiched between a cylinder head and a cylinder block, a combustion chamber hole bead provided on the gasket substrate and surrounding the combustion chamber hole endlessly, and the combustion chamber hole bead It is known that a water hole bead is provided on the gasket substrate on the outside and prevents water from flowing from the water hole from flowing into the combustion chamber hole (Patent Document 1).
In the cylinder head gasket, the combustion chamber hole bead and the water hole bead are separately provided at separate positions, and the combustion chamber hole bead surrounds the combustion chamber hole in an endless manner, The combustion gas is prevented from leaking outside.
On the other hand, the water hole bead surrounds the water hole in an endless manner so that water in the water hole does not leak to the outside and flow into the combustion chamber hole.

JP-A-9-72423

By the way, depending on the engine, it is necessary to provide the water hole at a position close to the combustion chamber hole. However, in the conventional cylinder head gasket, the combustion chamber hole bead and the water hole bead are separated from each other as described above. Since they are provided separately, there is a certain limit to providing them in close proximity, and it may be difficult to form water holes at desired positions.
In view of such circumstances, the present invention provides a cylinder head gasket capable of providing a water hole at a position closer to a combustion chamber hole than in the prior art.

That is, the present invention includes a gasket substrate sandwiched between a cylinder head and a cylinder block, a combustion chamber hole bead that is provided on the gasket substrate and surrounds the combustion chamber hole endlessly, and an outer side of the combustion chamber hole bead. In the cylinder head gasket provided with the water hole bead that is provided on the gasket substrate and prevents water from the water hole from flowing into the combustion chamber hole,
The combustion chamber hole bead and the water hole bead are formed in a trapezoidal cross section, and one inclined surface of the trapezoidal cross section is used as a combustion chamber hole bead surrounding the combustion chamber hole endlessly, The other inclined surface of the shape is formed at a position between the combustion chamber hole bead and the water hole to form a water hole bead, and the water hole bead is formed so as to surround the combustion chamber hole endlessly. To prevent water from the water hole from flowing into the combustion chamber hole,
Further, the height of the inclined surface of the combustion chamber hole bead is set higher than the height of the inclined surface of the water hole bead, and / or the width of the inclined surface of the combustion chamber hole bead is set to the width of the inclined surface of the water hole bead. It is characterized by being set narrower.

According to the above configuration, the combustion chamber hole bead and the water hole bead are formed into a trapezoidal cross section, and one inclined surface of the trapezoidal cross section is used as a combustion chamber hole bead and the other inclined surface is a water hole bead. Therefore, it is possible to form the combustion chamber hole and the water hole at positions close to each other as compared with the case where the combustion chamber hole bead and the water hole bead are formed separately.
Further, since the water hole bead is formed so as to surround the combustion chamber hole in an endless manner, water from the water hole can be prevented from flowing into the combustion chamber hole.
Further, the height of the inclined surface of the combustion chamber hole bead is set higher than the height of the inclined surface of the water hole bead, and / or the width of the inclined surface of the combustion chamber hole bead is set to the width of the inclined surface of the water hole bead. Therefore, the surface pressure of the combustion chamber hole bead and the surface pressure of the water hole bead can be set to optimum surface pressures, respectively. More specifically, the surface pressure around the combustion chamber hole can be increased to prevent the combustion gas from leaking to the outside, and at the same time, the surface pressure around the water hole can be decreased to improve durability. It is possible to satisfactorily prevent water from flowing into the combustion chamber hole while improving.

The top view which shows 1st Example of this invention Sectional view along line II-II in FIG. Sectional drawing which shows 2nd Example of this invention Sectional drawing which shows 3rd Example of this invention

1 and 2, the cylinder head gasket 1 includes an upper first gasket substrate 2 that is in contact with the lower surface of an upper cylinder head (not shown) and a lower gasket (not shown). A lower second gasket substrate 3 that contacts the upper surface of the cylinder block, and a shim plate 4 disposed between the first gasket substrate 2 and the second gasket substrate 3 are further provided.
In the illustrated embodiment, the two gasket substrates 2 and 3 and the shim plate 4 are provided with four combustion chamber holes 5 at positions corresponding to the four cylinder bores provided in series with the cylinder block.

  The two gasket substrates 2 and 3 are formed in a substantially rectangular shape so as to cover the entire upper surface of a cylinder block (not shown), but the shim plate 4 is a portion around the combustion chamber hole 5. 4 is formed in a ring shape so that only a single shim plate 4 can be surrounded by connecting the ring-shaped portions between adjacent combustion chamber holes 5 and 5. A combustion chamber hole 5 is formed. The shim plate 4 may be configured separately so as to surround each combustion chamber hole 5 independently.

Each gasket substrate 2, 3 includes a plurality of water holes 8 around each combustion chamber hole 5, and is used to fasten the cylinder head and the cylinder block at a position outside the water holes 8. A plurality of bolt holes 9 are formed.
Further, blow-by holes 10 for allowing blow-by gas to flow are provided outside the plurality of bolt holes 9.

Each of the gasket substrates 2 and 3 is formed with combustion chamber hole beads 2a and 3a provided on the gasket substrates 2 and 3 so as to endlessly surround the combustion chamber holes 5, respectively. Water hole beads 2b and 3b are formed on the outer sides of 2a and 3a to prevent water from the water hole 8 from flowing into the combustion chamber hole 5.
The combustion chamber hole beads 2a and 3a and the water hole beads 2b and 3b formed on the two upper and lower gasket substrates 2 and 3 are formed at the same upper and lower positions, respectively, and the combustion formed on the upper first gasket substrate 2 The chamber hole bead 2a and the water hole bead 2b protrude upward toward the upper cylinder head, and the combustion chamber hole bead 3a and the water hole bead 3b formed on the lower second gasket substrate 3 are directed toward the lower cylinder block. Projecting downward.

As shown in FIG. 2, the combustion chamber hole beads 2a and 3a and the water hole beads 2b and 3b are integrally formed in a trapezoidal cross section, and one inclined surface of the trapezoidal cross section is formed on the combustion surface. The combustion chamber hole beads 2a and 3a surround the chamber hole 5 in an endless manner. Each combustion chamber hole bead 2a, 3a is formed so as to surround the combustion chamber hole 5 independently, and the combustion gas in the combustion chamber hole 5 is leaked to the outside by each combustion chamber hole bead 2a, 3a. It can be prevented.
On the other hand, the other inclined surface of the trapezoidal cross section is formed as water hole beads 2b and 3b, and each water hole bead 2b and 3b includes the combustion chamber hole beads 2a and 3a and the water holes as shown in FIG. 8 and is formed so as to surround the four combustion chamber holes 5 in an endless manner in common. That is, each water hole bead 2b, 3b does not surround each of the four combustion chamber holes 5, independently, but can surround the four combustion chamber holes 5 in common by one water hole bead 2b, 3b. It is formed so that it can be done.
And since each water hole bead 2b, 3b is located in the position between the combustion chamber hole bead 2a, 3a and the water hole 8, it prevents water from the water hole 8 from flowing into the combustion chamber hole 5. can do.

Further, as shown in FIG. 2, in this embodiment, the height H1 of the inclined surfaces of the combustion chamber hole beads 2a and 3a is set higher than the height H2 of the inclined surfaces of the water hole beads 2b and 3b. And the width W1 of the inclined surface of the combustion chamber hole beads 2a, 3a is set to be narrower than the width W2 of the inclined surface of the water hole beads 2b, 3b.
Therefore, the surface pressure around each combustion chamber hole 5 by the combustion chamber hole beads 2a, 3a can be increased, and thereby, the combustion gas in the combustion chamber hole 5 can be well prevented from leaking to the outside. it can.
On the other hand, the surface pressure of the water hole beads 2b and 3b can be made lower than the surface pressure around the combustion chamber hole 5, thereby improving the durability of the water hole beads 2b and 3b. Water can be satisfactorily prevented from flowing into the combustion chamber hole 5.

Furthermore, one half bead 2c, 3c is provided in a position that surrounds the entire outside of the water hole 8 in an endless manner and on the inside of the blow-by hole 10 in the same upper and lower portions of the gasket substrates 2, 3 respectively. It is.
Each half bead 2c, 3c is projected so as to be in the same direction as that of the combustion chamber hole beads 2a, 3a and the water hole beads 2b, 3b, and the water from the water hole 8 is allowed to flow by these half beads 2c, 3c. This prevents the air from flowing into the blow-by hole 10 and at the same time prevents leakage to the outside.

Further, the shim plate 4 provided between the two gasket substrates 2 and 3 extends from the position of the combustion chamber hole 5 to the upper and lower combustion chamber hole beads 2a and 3a and the water hole beads 2b and 3b. Thus, the cylinder head gasket 1 has three sheets at the portion where the shim plate 4 is interposed, and two sheets at the outer portion of the shim plate 4.
With such a configuration, the surface pressure in the range where the shim plate 4 is provided can be made higher than the surface pressure of the other portions, whereby the combustion chamber hole beads 2a, 3a and the water hole beads 2b, 3b Each sealing effect can be enhanced.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the height H1 of the inclined surface of the combustion chamber hole beads 2a, 3a is the height of the inclined surface of the water hole beads 2b, 3b. Although set higher than H2, the width W of the inclined surfaces of the combustion chamber hole beads 2a and 3a and the width W of the inclined surfaces of the water hole beads 2b and 3b are set to be the same.
Other configurations are the same as those in the first embodiment.
Also in the second embodiment having the above-described configuration, the surface pressure of the combustion chamber hole beads 2a and 3a can be set high, and the surface pressure of the water hole beads 2b and 3b can be set low. An effect can be obtained.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, the height H of the inclined surfaces of the combustion chamber hole beads 2a and 3a and the height H of the inclined surfaces of the water hole beads 2b and 3b are shown. Are set to be the same, but the width W1 of the inclined surfaces of the combustion chamber hole beads 2a and 3a is set to be narrower than the width W2 of the inclined surfaces of the water hole beads 2b and 3b.
Other configurations are the same as those in the first embodiment.
Also in the third embodiment having the above-described configuration, the surface pressure of the combustion chamber hole beads 2a and 3a can be set high, and the surface pressure of the water hole beads 2b and 3b can be set low. An effect can be obtained.

  In the above-described embodiment, the cylinder head gasket 1 is constituted by the two gasket substrates 2 and 3 and the shim plate 4 provided therebetween, but the present invention is not limited to this. If necessary, the shim plate 4 can be omitted and one of the gasket substrates can be omitted.

DESCRIPTION OF SYMBOLS 1 Cylinder head gasket 2, 3 Gasket board | substrate 2a, 3a Combustion chamber hole bead 2b, 3b Water hole bead 2c, 3c Half bead 4 Shim plate 5 Combustion chamber hole 8 Water hole

Claims (4)

A gasket substrate sandwiched between a cylinder head and a cylinder block; a combustion chamber hole bead provided on the gasket substrate to endlessly surround the combustion chamber hole; and the gasket substrate outside the combustion chamber hole bead. In a cylinder head gasket provided with a water hole bead that is provided and prevents water from the water hole from flowing into the combustion chamber hole,
The combustion chamber hole bead and the water hole bead are formed in a trapezoidal cross section, and one inclined surface of the trapezoidal cross section is used as a combustion chamber hole bead surrounding the combustion chamber hole endlessly, The other inclined surface of the shape is formed at a position between the combustion chamber hole bead and the water hole to form a water hole bead, and the water hole bead is formed so as to surround the combustion chamber hole endlessly. To prevent water from the water hole from flowing into the combustion chamber hole,
Further, the height of the inclined surface of the combustion chamber hole bead is set higher than the height of the inclined surface of the water hole bead, and / or the width of the inclined surface of the combustion chamber hole bead is set to the width of the inclined surface of the water hole bead. Cylinder head gasket characterized in that it is set narrower.   The cylinder head gasket includes two gasket substrates superposed on each other, and the combustion chamber hole bead and the water hole bead formed on each gasket substrate are formed at the same position on the upper and lower sides, The combustion chamber hole bead and the water hole bead formed on the gasket substrate protrude upward, and the combustion chamber hole bead and the water hole bead formed on the lower gasket substrate protrude downward. The cylinder head gasket according to claim 1.   A shim plate is interposed between the two gasket substrates, and the shim plate extends from the position of the combustion chamber hole to a position beyond the upper and lower combustion chamber hole beads and the water hole bead. 3. The cylinder head gasket according to claim 2, wherein the cylinder head gasket includes three sheets at a portion where the shim plate is interposed and two cylinder head gaskets at an outer portion than the shim plate.   The cylinder head gasket according to any one of claims 1 to 3, wherein a half bead surrounding the outside of the combustion chamber hole and the water hole is provided outside the gasket substrate.

Images