JP2009114863A - Cylinder head gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder head gasket capable of providing good sealing performance by self sealing effect and of being easily manufactured. <P>SOLUTION: A first and a second full beads 2a, 3a projecting toward a third seal plate 4 at a center are provided on a first seal plate 2 and a second seal plate 3 comprising a cylinder head gasket 1, and the first and the second full beads 2a, 3a construct an adhesion part 8 strongly adheres on the third seal plate 4 and sealing combustion gas. The third seal plate 4 is provided with a hemming part 10. A space 9 is formed by the hemming part 10 and the adhesion part 8. A slit 10a providing communication between a combustion chamber hole 5 and the space 9 is provided on the hemming part 10. When combustion gas flows in the space 9 via the slit 10a, the first seal plate 2 and the third seal plate 4 are pressed in a vertical direction by self sealing effect. The gasket can provide good sealing properties and can be easily manufactured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cylinder head gasket, and more particularly, to a cylinder head gasket that seals between a cylinder head and a cylinder block.

2. Description of the Related Art Conventionally, a cylinder head gasket is known which is composed of a plurality of seal plates sandwiched between a cylinder head and a cylinder block and having combustion chamber holes.
As such a cylinder head gasket, there is known a cylinder head gasket that utilizes a self-sealing effect to seal between a cylinder head and a cylinder block (Patent Document 1).
In the cylinder head gasket of Patent Document 1, a seal plate on the cylinder head side is formed with a protrusion that surrounds the combustion chamber hole and protrudes toward the cylinder head, and the radially central portion of the protrusion is a cylinder block. It protrudes toward the side.
Also, the seal plate on the cylinder block side is provided with a protruding portion that surrounds the combustion chamber hole and protrudes toward the cylinder block side, and the radially central portion of the protruding portion protrudes toward the cylinder head side. Yes.
Then, both the seal plates are superposed so that the central portions in the radial direction of both protrusions are continuously adhered in the circumferential direction.
According to the cylinder head gasket having the above-described configuration, the radially central portions of both protrusions are in close contact with each other in the circumferential direction. At the same time as pressing one protrusion toward the cylinder head, the other protrusion is pressed toward the cylinder block.
When one protrusion is pressed against the cylinder head by the pressure of the combustion gas, the sealing performance of the pressing portion is improved, and when the other protrusion is pressed against the cylinder block by the pressure of the combustion gas, the pressing portion The sealing performance is also improved.
Furthermore, when one protrusion is pressed against the cylinder head and the other protrusion is pressed against the cylinder block, the reaction force causes the radial central portion of one protrusion and the radial central portion of the other protrusion to Since it comes to adhere | attach more strongly, the sealing performance in the part comes to improve.
That is, the cylinder head gasket of Patent Document 1 can obtain a good sealing effect due to the self-sealing effect utilizing the pressure of the combustion gas.
JP 2000-88105 A

However, in the cylinder head gasket disclosed in Patent Document 1, a protrusion is formed on each of the seal plate on the cylinder head side and the seal plate on the cylinder block side, and the central portions in the radial direction of the protrusions are mutually circumferential. There is a drawback in that both seal plates must be manufactured with high precision because they must be in close contact with each other in the direction.
In view of such circumstances, the present invention provides a cylinder head gasket that can obtain a good sealing property due to a self-sealing effect and can be easily manufactured.

That is, the present invention is a cylinder head gasket that is sandwiched between a cylinder head and a cylinder block and includes a plurality of seal plates each formed with a combustion chamber hole.
An adhesion portion that surrounds the combustion chamber hole and tightly adheres the seal plates to each other; sealing means that surrounds the combustion chamber hole on the combustion chamber hole side with respect to the adhesion portion; and the sealing means and the adhesion portion And a communication passage that communicates the space with the combustion chamber hole.

According to the above invention, when the cylinder head gasket is sandwiched between the cylinder head and the cylinder block, a space is formed between the seal plate by the contact portion and the sealing member.
Combustion gas flows into this space through the communication path, and this combustion gas is sealed by the contact portion. Therefore, the cylinder head side seal plate is used as the cylinder head, and the cylinder block side seal plate. Can be brought into close contact with the cylinder block.
That is, it is possible to obtain a good sealing property due to the so-called self-sealing effect using the pressure of the combustion gas, and to easily manufacture the cylinder head gasket because it is configured to form a communication path with the sealing member. .

The first embodiment of the present invention will be described below. The cylinder head gasket 1 shown in FIGS. 1 and 2 is sandwiched between a cylinder head and a cylinder block (not shown) so as to seal between them. Yes.
The cylinder head gasket 1 includes three first to third seal plates 2 to 4 that are superposed on each other, the first seal plate 2 is located above and contacts the cylinder head, and the second seal plate 3 is below The third seal plate 4 is located between the first and second seal plates 2 and 3.
These first to third seal plates 2 to 4 each have a plurality of combustion chamber holes 5 formed in accordance with the cylinder bores, a plurality of bolt holes 6 through which fastening bolts are inserted, and a coolant for circulation. Water holes 7 and oil holes (not shown) for circulating lubricating oil are formed.
Further, a coating material such as a fluorine or nitrile rubber or elastomer material is applied to the surface of the upper first seal plate 2, that is, the contact surface with the cylinder head, and the lower second seal plate 3. The same coating material is also applied to the surface of this, that is, the contact surface with the cylinder block.
Furthermore, the coating material is also applied to the contact surface between the first seal plate 2 and the third seal plate 4 and the contact surface between the third seal plate 4 and the second seal plate 3.
The above coating materials are provided for the purpose of improving the adhesion and sealing properties with the counterpart material, respectively, and if necessary, in order to ensure slipperiness and non-adhesiveness, the surface of the above coating material A top coat such as graphite or wax may be applied.

The first and second seal plates 2 and 3 are formed with first and second full beads 2 a and 3 a that endlessly surround the combustion chamber hole 5, and the first full bead 2 a is the second seal plate 3. The second full bead 3 a is formed so as to protrude toward the first seal plate 2.
For this reason, when the cylinder head gasket 1 is sandwiched between the cylinder head and the cylinder block, the top portion of the first full bead 2a and the third seal plate 4 are in close contact with each other to form the contact portion 8, and the contact portion 8 The combustion gas generated in the combustion chamber is sealed.
On the other hand, the top portion of the second full bead 3a is also in close contact with the third seal plate 4 to form a close contact portion 8. The close contact portion 8 seals the combustion gas generated in the combustion chamber. ing.

Next, a hemming portion 10 as a sealing means is formed on the first seal plate 2 side of the third seal plate 4 so as to surround the combustion chamber hole 5.
The hemming portion 10 is formed by drilling a hole having a diameter smaller than the diameter of the combustion chamber hole 5 in the third seal plate 4 and then folding back by hemming at the position of the combustion chamber hole 5.
Further, the tip of the hemming portion 10 is located closer to the combustion chamber hole 5 than the close contact portion 8 formed by the first full bead 2a, and the coating material is applied to the upper surface of the hemming portion 10.
For this reason, when the cylinder head gasket 1 is sandwiched between the cylinder head and the cylinder block, the hemming portion 10 and the first seal plate 2 are in close contact with each other in an airtight state, and the combustion gas generated in the combustion chamber is sealed. It is supposed to be.
From the above, when the cylinder head gasket 1 is sandwiched between the cylinder head and the cylinder block, the hemming portion 10 and the close contact portion 8 are between the first seal plate 2 and the third seal plate 4. A space 9 is formed between them.

The hemming portion 10 is formed with at least one slit 10a as a communication passage, and the space 9 and the combustion chamber hole 5 are communicated with each other by the slit 10a.
When the third seal plate 4 is manufactured, the slit 10a forms a notch penetrating the third seal plate 4 at the same time as making a hole having a smaller diameter than the combustion chamber hole 5, and then hemming by hemming When the portion 10 is formed, the notch is formed as a slit 10a.
By forming the slit 10a, the combustion gas generated in the combustion chamber flows into the space 9 formed between the first seal plate 2 and the third seal plate 4 through the slit 10a.
The combustion gas that has flowed into the space 9 presses the first seal plate 2 toward the cylinder head and the third seal plate 4 toward the cylinder block due to a self-sealing effect.
As a result, the first seal plate 2 and the cylinder head can be in close contact with each other to seal between them. On the other hand, since the 3rd seal plate 4 presses the 2nd seal plate 3, the 2nd seal plate 3 and a cylinder block can closely_contact | adhere, and it can seal so that combustion gas may not leak between these.
Thus, since the sealing performance around the combustion chamber hole 5 can be improved by the self-sealing effect, good sealing performance can be obtained even if the fastening force of the fastening bolt during engine assembly is reduced.
For this reason, the durability of the cylinder head gasket 1 can be improved, and in the case where the cylinder block is made of aluminum, it is possible to prevent indentation due to tightening, so that the sealing performance does not deteriorate due to the indentation. .
Further, a close contact portion 8 and a hemming portion 10 are provided to form the space 9 between the first seal plate 2 and the third seal plate 4, and a slit 10 a for communicating the space 9 with the combustion chamber hole 5 is formed. Since it only needs to be formed, it can be easily manufactured.

In the cylinder head gasket 1 according to the first embodiment, a shim having a predetermined thickness is provided as a sealing member between the first seal plate 2 and the third seal plate 4 in place of the hemming portion 10. May be.
In this case, if a groove or a slit is formed on the surface of the shim as a communication path for communicating the combustion chamber hole 5 and the space 9, a good sealing property due to the self-sealing effect can be easily obtained as in the above embodiment. Obtainable.
Further, the third seal plate 4 of the cylinder head gasket 1 in the first embodiment may be provided with a shim as a sealing member in which a groove as a communication path is formed on the side opposite to the hemming portion 10.
With such a configuration, a space is formed between the second seal plate 3 and the third seal plate 4 between the close contact portion 8 by the second full bead 3a and the shim by the shim. It becomes.
And since combustion gas flows in into this space through the said groove | channel, the 2nd seal plate 3 comes to closely_contact | adhere to a cylinder block by a self-sealing effect, and favorable sealing performance can be obtained.

FIG. 3 shows a cylinder head gasket 1 according to the second embodiment.
The cylinder head gasket 1 of the present embodiment is composed of first and second seal plates 2 and 3, and the first and second seal plates 2 and 3 are similar to the cylinder head gasket 1 of the first embodiment in the combustion chamber. A hole 5, a bolt hole, a water hole, and an oil hole are formed.
In addition, first and second full beads 2a and 3a are formed on the first and second seal plates 2 and 3 in opposite directions, and the tops of the first and second full beads 2a and 3a are in close contact with each other. By doing so, the contact portion 8 is configured to seal the combustion gas.
A ring-shaped shim 11 is fixed to the first seal plate 2, and at least one groove 11 a is formed in the shim 11 as a communication path.

According to the cylinder head gasket 1 having such a configuration, when the cylinder head gasket 1 is sandwiched between the cylinder head and the cylinder block, the shim between the first seal plate 2 and the second seal plate 3 is provided. 11 and a space 9 are formed between the contact portion 8 and the contact portion 8.
On the other hand, since the groove 11a is formed in the shim 11, the combustion gas enters the space 9 through the groove 11a, and the first seal plate 2 is in close contact with the cylinder head due to the self-sealing effect. The second seal plate 3 is in close contact with the cylinder block to seal the combustion gas.
Thus, the cylinder head gasket 1 according to the present embodiment also has a good sealing property due to the self-sealing effect, and can be easily manufactured.
In the second embodiment, the shim 11 may be a hemming portion as in the first embodiment. If a slit is formed as a communication path in the hemming portion, the same effect as in the present embodiment can be obtained. Can do.

FIG. 4 shows a shim 11 having a different structure as the shim 11 in the second embodiment. The shim 11 has a so-called honeycomb structure.
The innumerable passages 11b constituting the honeycomb structure are formed radially from the combustion chamber holes 5, and each passage 11b constitutes a communication passage that allows the combustion chamber holes 5 and the space 9 to communicate with each other. Yes.
With such a configuration, the combustion gas enters the space 9 through the passages 11b, so that the same effect as that of the second embodiment can be obtained by the self-sealing effect.

FIG. 5 shows a cylinder head gasket 1 according to the third embodiment.
The cylinder head gasket 1 of the present embodiment is constituted by first to third seal plates 2 to 4 as in the first embodiment, and the first to third seal plates 2 to 4 include the cylinder head of the first embodiment. Like the gasket 1, combustion chamber holes 5, bolt holes, water holes, and oil holes are formed.
The first and second seal plates 2 and 3 are formed with first and second full beads 2a and 3a, a contact portion between the first full bead 2a and the third seal plate 4, a second full bead 3a and a second full bead 3a. 3 The contact portion with the seal plate 4 is in close contact with each other to form a contact portion 8 for sealing the combustion gas.
The third seal plate 4 is formed with a corrugated portion 12 by a plurality of projections formed radially from the combustion chamber hole 5, and the top portions of the radial corrugated portion 12 on the upper side and the lower side are respectively formed. Projecting upward and downward from the flat end of the third seal plate 4.
With such a configuration, the top of each projection of the corrugated part 12 and the first seal plate 2 are strongly in close contact with each other, so that the corrugated part is between the first seal plate 2 and the third seal plate 4. A space 9 is formed between the portion 12 and the close contact portion 8, and similarly, a space 9 is also formed between the second seal plate 3 and the third seal plate 4.
On the other hand, a communication passage 12a that connects the combustion chamber hole 5 and the space 9 is formed between the protrusions forming the corrugated portion 12, so that the combustion gas passes through the communication passage 12a. It flows into the space 9.
According to the cylinder head gasket 1 having such a configuration, the combustion gas that has flowed in through the communication passage 12a is sealed by the contact portion 8, so that the first seal plate 2 is brought into the cylinder head by the self-sealing effect, The seal plates 3 are in close contact with the cylinder block, and good sealing properties can be obtained.
Further, since the first and second full beads 2a and 3a and the radial corrugated portion 12 surrounding the combustion chamber hole 5 may be formed, the cylinder head gasket 1 can be easily manufactured.

FIG. 6 shows a cylinder head gasket 1 according to the fourth embodiment.
The cylinder head gasket 1 of the present embodiment is constituted by first to third seal plates 2 to 4 as in the first embodiment, and the first to third seal plates 2 to 4 include the cylinder head of the first embodiment. Like the gasket 1, combustion chamber holes 5, bolt holes, water holes, and oil holes are formed.
The first and second seal plates 2 and 3 are formed with first and second full beads 2a and 3a, a contact portion between the first full bead 2a and the third seal plate 4, a second full bead 3a and a second full bead 3a. 3 The contact portion with the seal plate 4 is in close contact with each other to form a contact portion 8 for sealing the combustion gas.
On the other hand, the third seal plate 4 is formed with an annular corrugated portion 13 composed of a plurality of protrusions surrounding the combustion chamber hole 5, and the top portions of the annular corrugated portion 13 on the upper side and the lower side are respectively the first. 3 protrudes upward and downward from the flat end of the seal plate 4.
With such a configuration, the top of each projection of the corrugated portion 13 and the first seal plate 2 are in close contact with each other, so that the corrugated portion is between the first seal plate 2 and the third seal plate 4. A space 9 is formed between the first seal plate 13 and the contact portion 8, and similarly, a space 9 is also formed between the second seal plate 3 and the third seal plate 4.
On the other hand, a groove 13a that connects the combustion chamber hole 5 and the space 9 is formed in a part of the annular corrugated portion 13 by deforming the protrusion, and the combustion gas is formed through the groove 13a. Flows into the space 9.
According to the cylinder head gasket 1 having such a configuration, the combustion gas flowing in through the groove 13a is sealed by the contact portion 8, and the first seal plate 2 becomes the cylinder head and the second seal plate 3 by the self-sealing effect. Since they are closely attached to the cylinder block, good sealing properties can be obtained.
Further, since the annular corrugated portion 13 may be formed so as to surround the first and second full beads 2a, 3a and the combustion chamber hole 5, the cylinder head gasket 1 can be easily manufactured.

FIG. 7 shows a cylinder head gasket 1 according to the fifth embodiment.
The cylinder head gasket 1 of the present embodiment is constituted by first to third seal plates 2 to 4 as in the first embodiment, and the first to third seal plates 2 to 4 include the cylinder head of the first embodiment. Like the gasket 1, combustion chamber holes 5, bolt holes, water holes, and oil holes are formed.
The first and second seal plates 2 and 3 are formed with first and second full beads 2a and 3a, a contact portion between the first full bead 2a and the third seal plate 4, a second full bead 3a and a second full bead 3a. 3 The contact portion with the seal plate 4 is in close contact with each other to form a contact portion 8 for sealing the combustion gas.
Further, hemming portions 14 and 15 bent by hemming toward the third seal plate 4 are formed in the portions of the combustion chamber holes 5 of the first and second seal plates 2 and 3, respectively. The portions 14 and 15 are in contact with the third seal plate 4.
With such a configuration, the hemming portions 14 and 15 and the first and second hemming portions 14 and 15 are provided between the first seal plate 2 and the third seal plate 4 and between the second seal plate 3 and the third seal plate 4. Spaces 9 are respectively formed between the full beads 2a and 3a and the close contact portion 8.
On the other hand, the third seal plate 4 is provided with a slit 16 as a communication hole penetrating vertically, and the tip of the slit 16 is provided to the close contact portion 8 side with respect to the hemming portions 14 and 15. As a result, the combustion chamber hole 5 and the space 9 communicate with each other.
According to the cylinder head gasket 1 having such a configuration, the combustion gas that has flowed into the space 9 through the slit 16 is sealed by the contact portion 8, and the first seal plate 2 is moved to the cylinder head side by a self-sealing effect. In addition, since the second seal plate 3 is strongly pressed to the cylinder block side, good sealing performance can be obtained.
In addition, since the hemming portions 14 and 15 are provided in the first and second seal plates 2 and 3 and the slit 16 is provided in the third seal plate 4, the cylinder head gasket 1 can be easily manufactured. .

In each of the above embodiments, the close contact portion 8 is formed by strongly adhering the full bead to the opposing seal plate or full bead. However, as another method for forming the close contact portion 8, the seal plates may be laser bonded to each other. It is also possible to adhere using a heat-resistant adhesive such as welding, polyimide or inorganic.
In any case, it is only necessary to seal the combustion gas that is leaking between the seal plates. In particular, when an adhesive is used, the entire surface of the portion further outside the bonded portion is bonded. May be.

The top view of the cylinder head gasket concerning a 1st Example. Sectional drawing of the cylinder head gasket concerning a 1st Example. Sectional drawing of the cylinder head gasket concerning a 2nd Example. Sectional drawing of the cylinder head gasket using the shim of a different structure with respect to 2nd Example. Sectional drawing of the cylinder head gasket concerning a 3rd Example. Sectional drawing of the cylinder head gasket concerning a 4th Example. Sectional drawing of the cylinder head gasket concerning a 5th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder head gasket 2-4 1st-3rd seal plate 5 Combustion chamber hole 8 Contact | adherence part 9 Space 10 Hemming part 10a Slit 11 Shim 11a Groove 11b Passage 12 Waveform part 12a Communication path 13 Waveform part 13a Groove 16 Slit

Claims (8)

In the cylinder head gasket, which is sandwiched between the cylinder head and the cylinder block and includes a plurality of seal plates each formed with a combustion chamber hole,
An adhesion portion that surrounds the combustion chamber hole and tightly adheres the seal plates to each other; sealing means that surrounds the combustion chamber hole on the combustion chamber hole side with respect to the adhesion portion; and the sealing means and the adhesion portion A cylinder head gasket, further comprising a space formed between and a communication passage for communicating the space with the combustion chamber hole.   The sealing means is a hemming portion formed by bending at least one seal plate toward the other seal plate, or a shim provided between the seal plate and the seal plate. Cylinder head gasket as described.   The said sealing | blocking means is a honeycomb-shaped shim provided with many channel | paths formed toward the radial direction from the combustion chamber hole, Comprising: The said communication channel is each said channel | path, The said channel | path is characterized by the above-mentioned. Cylinder head gasket.   The cylinder head gasket according to claim 1, wherein the communication path is a slit or a groove formed in the sealing unit.   Three seal plates are provided, and a corrugated portion made up of a plurality of protrusions formed radially from the combustion chamber hole is provided as a sealing means on the central seal plate, and the communication path forms each corrugated portion. The cylinder head gasket according to claim 1, wherein the cylinder head gasket is formed between the protrusions.   Three seal plates are provided, and a corrugated portion made of an annular projection surrounding the combustion chamber hole is formed as the sealing means on the central seal plate, and the communication path crosses the corrugated portion and the space. 2. The cylinder head gasket according to claim 1, wherein the cylinder head gasket is a groove communicating with the combustion chamber hole.   Three sealing plates are provided, and a hemming portion bent toward the central sealing plate is provided on the sealing plate located outside as a sealing means, and the central sealing plate is connected to the central sealing plate as a communication path than the tip of the hemming portion. The cylinder head gasket according to claim 1, wherein a slit formed to the side is provided.   The contact portion is formed at a contact portion between a full bead that protrudes from at least one of the seal plates toward the other seal plate and the other seal plate with which the full bead contacts, or the seal plates are welded together. The cylinder head gasket according to any one of claims 1 to 7, wherein the cylinder head gasket is formed.

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