JPH05187555A - Cylinder head gasket - Google Patents

Abstract

PURPOSE:To improve the heat conductibility from a cylinder head to a cylinder block, as to a cylinder gasket. CONSTITUTION:On the metallic part of a cylinder head gasket 1 which is connected to a cylinder head or a cylinder block, a heat transfer compound 8 with an excellent heat conductibility is applied. As an example to simplify the application work, a grommet 6 with U shape section is provided at the inner peripheral edge 2a of a bore aperture 3 formed on a metallic gasket base material 2, and the heat transfer compound 8 is sealed in a clearance 7 formed between the grommet 6 and the base material 2. When the gasket 1 is held between the cylinder head and the cylinder block, the grommet 6 is crushed in the up and down direction, and the heat transfer compound 8 is pushed out on the surface of the base material 2 (the arrow A), and held between the surface of the base material 2, and the metallic contact surface of the cylinder head and the cylinder block.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder gasket installed between a cylinder head and a cylinder block of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, for example, a gasket disclosed in Japanese Utility Model Laid-Open No. 61-55146 has a three-layer structure in which steel plates are sandwiched between upper and lower asbestos layers, and a metal grommet and its steel plate are used. There is a structure in which the heat flow from the grommet is promoted by connecting to prevent the grommet from being thermally deteriorated. Further, a gasket in which a base material of the gasket is formed of a metal plate and a metal grommet is provided on the metal gasket base material is well known. In the above two examples, the steel plate and the metal gasket base material form a refrigerant passage between the cylinder block and the cylinder head. Cooling with cooling water in this passage or the steel plate and the metal gasket base material Due to the heat released from the outer peripheral end surface to the outside air, the heat transfer from the grommet, which has a high temperature as described above, is favorably performed.

[0003]

As described above, the conventional gasket has the effect of promoting heat transfer from the grommet to prevent thermal deterioration of the grommet, but on the other hand, the gasket from the cylinder head to the cylinder block has been obtained. Insufficient heat transfer. That is, a metal grommet and a cylinder head,
The contact portion between each cylinder block or the contact portion between the gasket base material and the cylinder head or the cylinder block in the case of a metal gasket base material is a contact between metal surfaces. For this reason, the minute irregularities present on the metal surface form a minute air layer or an oil layer having poor heat transfer characteristics between itself and the mating surface, which hinders heat transfer at the contact portions. Therefore,
In the past, heat transfer from the cylinder head to the cylinder block was insufficient. When the heat transfer from the head to the block is improved, cooling of the inner wall of the combustion chamber formed in the cylinder head is promoted, and it is expected that the engine output and the fuel consumption can be reduced with the improvement of knocking. Therefore, if the heat transfer from the head to the block is insufficient as in the conventional case, the above effect cannot be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cylinder head gasket having improved heat transfer from the cylinder head to the cylinder block.

[0005]

In order to achieve the above object, the present invention provides a cylinder head gasket having a metal portion which is interposed between a cylinder head and a cylinder block and which is in contact with the cylinder head or the cylinder block. In the above, the heat conductive compound is applied to the surface of at least one of the cylinder head and the cylinder block of the metal portion which is in contact with the surface of the metal portion.

[0006]

The heat transfer compound fills minute irregularities existing on the metal surface, and the compound itself has excellent heat transfer characteristics. Therefore, in the present invention, when the heat transfer compound is applied to the surface of the metal part of the cylinder head gasket which is in contact with the cylinder head or the cylinder block, when the cylinder head gasket is sandwiched between the cylinder head and the cylinder block, the cylinder head The minute space conventionally formed between the surface of the metal part of the gasket and the contact surface of each of the cylinder head or cylinder block is filled with a heat-conductive compound, and the space between the cylinder head and the cylinder head gasket or between the cylinder block and The heat transfer between the cylinder head gasket and the cylinder head gasket is improved.

[0007]

1 is a plan view of a cylinder head gasket according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line II--II in FIG.

In FIG. 1, a cylinder head gasket (hereinafter, simply referred to as a gasket) 1 is a gasket interposed between a cylinder head (not shown) and a cylinder block (not shown) of an in-line four-cylinder engine. The figure shows a part thereof. In the figure, 2 is a gasket base material made of a metal plate, 3 is an opening provided in the gasket base material 2 according to the position of the bore portion of the cylinder block, 4 is a head bolt hole through which a head bolt is inserted, and 5 is an oil. It is a pit. The head bolt hole 4 and the oil drop hole 5
Each is provided on the gasket base material 2. Further, a metal grommet 6 is annularly provided on the inner peripheral edge of the opening 3.

As shown in FIG. 2, the grommet 6 is substantially U-shaped between the inner peripheral edge portion 2a of the opening 3 of the gasket base material 2.
The gasket base material 2 is formed so that a V-shaped gap 7 is formed.
It has a U-shaped cross section with a large dimension relative to the thickness dimension of. In this embodiment, the heat transfer compound 8 is enclosed in the gap 7. The heat transfer compound 8 fills minute irregularities existing on the metal surface and has excellent heat transfer property by itself. For example, the heat transfer compound 8 is applied between the power transistor and the heat sink, It is a well-known material that improves heat conductivity. This heat transfer compound 8 is a mixture of metal oxide powder and fats and oils in the form of grease. For example, silicone grease or the like is well known. Further, the gasket base material 2 has a two-layer structure of a metal plate as shown in FIG.

FIG. 3 is a sectional view showing a mounting state of the gasket 1. When the gasket 1 having the above-mentioned configuration is sandwiched at a predetermined position between the cylinder block 10 and the cylinder head 20 and head bolts (not shown) are evenly tightened over the entire surface of the gasket 1, the grommet 6 becomes The contact portions 6a on both the upper and lower sides are crushed and deformed in a direction approaching the surface of the gasket base material 2. Since the volume of the gap 7 shown in FIG. 2 decreases as the grommet 6 is deformed, the heat transfer compound 8 enclosed in the gap 7 is reduced.
Are extruded onto the surface of the gasket base material 2 through the gap between the contact portion 6a and the gasket base material 2 (indicated by arrow A in FIG. 2).

When the work of tightening the head bolt is advanced, the cylinder block 10 and the cylinder head 20 of the heat transfer compound 8 extruded onto the surface of the gasket base material 2 due to the deformation of the grommet 6 are removed by the gasket 1 Spreads over the surface of the gasket base material 2 as
When the head bolt is completely tightened, as shown in FIG. 3, between the lower surface of the gasket base material 2 and the upper surface of the cylinder block 10, and between the upper surface of the gasket base material 2 and the lower surface of the cylinder head 20. It will be in a state where it extends evenly over almost the entire area between and.

The heat transfer compound 8 is provided between the surface of the gasket base material 2 and the upper surface of the cylinder block 10 and the cylinder head 2 due to the unevenness existing on the metal surface.
It is filled in a minute space portion formed between the lower surface of 0.
As a result, heat transfer from the cylinder head 20 to the cylinder block 10 is improved by the action of the heat transfer compound 8 described above, and cooling of the inner wall 21a of the combustion chamber 21 provided in the cylinder head 20 is promoted. As the cooling of the combustion chamber 21 is improved, knocking is improved and the compression ratio can be further improved. As a result, the output of the engine can be increased and the fuel consumption can be reduced.

Further, when the head bolt has reached a predetermined torque and the tightening is completed, as shown in FIG. 3, both contact portions 6a of the grommet 6 are crushed until they are embedded in the gasket base material 2, thereby making both contacts. The sealing surface pressure between the outer surface of the portion 6a, the upper surface of the cylinder block 10 with which the outer surface is in contact, and the lower surface of the cylinder head 20 is a surface pressure sufficient to seal the combustion gas. The heat transfer compound 8 also extends between both contact portions 6a of the grommet 6 and the gasket base material 2 to improve the heat transfer between the grommet 6 and the gasket base material 2. Two
The effect of improving the heat transfer property from 0 to the block 10 can be made more effective, and the effect of preventing the thermal deterioration of the grommet 6 by cooling the grommet 6 described above can be obtained.

FIG. 4 is a plan view of a second embodiment of the cylinder head gasket according to the present invention, FIG. 5 is a sectional view taken along the line VV in FIG. 4, and FIG. 6 is an enlargement of the inner peripheral edge of the opening 3. A perspective view is shown. Incidentally, in FIG. 4, the same components as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

Like the first embodiment, the gasket 30 of this embodiment has a structure in which a metallic gasket base material 31 is provided with a metal grommet 32. Further, the gasket base material 31 has a two-layer structure of a metal plate. 4 to 6
As shown in FIG. 3, the metal plate 31b for one layer is formed with a plurality of notches 31c extending radially outward from the inner peripheral edge 31a of the opening 3. A cutout 31e is also formed in the metal plate 31d on the back surface of the metal plate 31b. Notch parts 31c, 31 of both metal plates 31b, 31d
e are alternately provided in the circumferential direction so as not to overlap with each other as shown in FIG.

As shown in FIG. 5, the grommet 32 has a U-shaped cross section of such a size that the contact portions 32a on the upper and lower sides contact the upper and lower surfaces of the gasket base material 31, and the inner peripheral edge portion 31a of the opening 3 has the same shape. It is installed all around. Therefore,
A gap 33 is formed inside the curved portion of the grommet 32 and in the notches 31c and 31e, and the heat transfer compound 34 is sealed in the gap 33. Here, the notches 31c and 31e are formed to have a length dimension that extends outside the tip end of the contact portion 32a of the grommet 32 mounted in a predetermined state, and the notch 3
The outer peripheral side portion of the grommet 32 of 1c and 31e is an opening 33a.

When the gasket 30 having the above-mentioned structure is sandwiched between the cylinder block and the cylinder head as described above and the head bolt is tightened, the grommet 32 is deformed by crushing the contact portions 32a toward each other. ,
The heat transfer compound 34 in the gap 33, the volume of which has been reduced by this deformation, is extruded onto the surface of the gasket base material 31 through the opening 33a (arrow B in FIG. 5).
). Although not shown, the gasket base material 3
Also on the back side of 1 (the surface side of the metal plate 31d), the heat transfer compound 34 is formed by the same action by the gasket base material 31.
Is extruded onto the surface of.

From this point onward, like the first embodiment described above,
The heat transfer compound 34 extends over substantially the entire surface between the surface of the metal gasket base material 31, the upper surface of the cylinder block, and the lower surface of the cylinder head.
The same effect as the embodiment can be obtained.

According to the second embodiment having the above construction, the grommet 32 can be held more reliably in the gasket before engine assembly. That is, in the first embodiment, as shown in FIG. 2, the grommet 6 was provided on the gasket base material 2 via the fluid heat transfer compound 8, and the holding of the grommet 6 was unstable. However, according to the second embodiment, the grommet 32 is directly fixed to the gasket base material 31 even before the engine is assembled, so that the grommet 32 can be held reliably, and a problem such as misalignment of the grommet during engine assembly occurs. Can be prevented.

In the second embodiment, the notch 31
Although the sealing surface pressure of the grommet 32 in the portion where the c and 31e are provided is reduced, the sealing surface pressure of the grommet 32 is provided by alternately providing the notches 31c and 31e on both sides in the circumferential direction as described above. Is dispersed in the circumferential direction of the grommet 32, and the grommet 3
The seal surface pressure of 2 is more uniform.

FIG. 7 is a perspective view of a third embodiment of the cylinder head gasket according to the present invention, and FIG. 8 is VIII--VIII in FIG.
A sectional view along the line is shown. Gasket 40 of this embodiment
Is processed into a wavy shape along the circumferential direction at the inner peripheral edge portion of the opening 43 in the metal gasket base material 41, and has a U-shaped cross-sectional shape as in the first and second embodiments. The metal grommet 42 having the above is provided in an annular shape on the wavy inner peripheral edge portion. Therefore, as shown in FIG. 8, the dimension of the grommet 42 on the opening side is larger than the thickness dimension of the gasket base material 41 as in the first embodiment, and the wavy gasket base material 41 and the grommet 42 are provided.
And a gap 45 in which the heat transfer compound 44 is enclosed.
Is formed.

When the gasket 40 having the above structure is sandwiched between the cylinder block and the cylinder head and the head bolt is tightened, the contact portions 42a on both upper and lower sides of the grommet 42 are formed.
Are squeezed toward each other, the heat transfer compound 44 in the gap 45 is extruded onto the surfaces on both sides of the gasket base material 41 in the same manner as in the first embodiment, and the surface of the metal gasket base material 41, It extends over substantially the entire surface between the upper surface of the cylinder block and the lower surface of the cylinder head. Therefore, also in this embodiment, the same effect as that of the first embodiment can be obtained.

Further, in the structure of the third embodiment, even with the grommet 42 having a large opening side dimension, the inner peripheral portion of the wavy gasket base material 41 and both contact portions 42 are formed.
a is contacted and supported. Therefore, according to the third embodiment, similarly to the second embodiment, the grommet 42 can be reliably held even before the engine is assembled, and problems such as misalignment of the grommet during engine assembly can be prevented. That is, the third embodiment is an embodiment which solves the problem that the grommet holding state is unstable in the first embodiment by making the inner peripheral edge of the gasket base material 41 wavy.

Each of the first to third embodiments described above is an example of a so-called metal gasket in which the gasket base material is made of metal. That is, the heat transfer compound is provided between the metal surface of the gasket base material, the cylinder block, and the cylinder head to improve the heat transfer property from the cylinder head to the cylinder block. However, the present invention is not limited to the above embodiment, and is also effective in a so-called soft gasket in which a non-metal material such as carbon is used as the gasket base material. In the soft gasket, a heat transfer compound is provided between the metal surface on the outside of the grommet contact portion and the contact portions of the cylinder block and the cylinder head, which have not been implemented in the first to third embodiments, and the heat transfer compound is provided. Improves heat transfer.

FIG. 9 is a plan view of a cylinder head gasket according to a fourth embodiment of the present invention, and FIG. 10 is a sectional view taken along line XX in FIG. In FIG. 9, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The gasket 50 of this embodiment has a structure in which a metal grommet 52 is annularly provided on the inner peripheral edge portion 51a of the opening 3 formed in the gasket base material 51 made of asbestos. The configuration is shown in. As shown in FIG. 10, the portion of the gasket base material 51 where the grommet 52 is provided is a grommet mounting portion 51b having a smaller thickness dimension than the other portions. on the other hand,
The grommet 52 has a substantially U-shaped cross-sectional shape that bulges in an elliptical shape, and is temporarily fixed by sandwiching the grommet mounting portion 51b at the tip ends of the contact portions 52a on both upper and lower sides. The grommet 52 and the grommet mounting portion 51 which are bulged in an elliptical shape
A gap 53 is formed between the heat transfer compound 54 and b, and the heat transfer compound 54 is sealed in the gap 53. The contact portions 52a on both sides of the grommet 52 are provided with small holes 52b for supplying the heat transfer compound 54 to the outside of the grommet 52. As shown in FIG. 9, many small holes 52b are evenly provided on the circumference of the grommet 52.

When the gasket 50 having the above structure is sandwiched between the cylinder block and the cylinder head and the head bolt is tightened, the contact portions 52a on both upper and lower sides of the grommet 52 are formed.
Are crushed toward each other, and the heat transfer compound 54 in the gap 53 is pushed out onto the upper and lower surfaces of the grommet 52 through the small holes 52b. When the head bolt is further tightened, the extruded heat transfer compound 54 spreads between the upper and lower surfaces of the grommet 52 and the contact surfaces of the cylinder block and each of the cylinder heads, and as described above, between the metal contact surfaces. The heat transfer compound 54 is filled in the formed space. Therefore, according to this embodiment, the grommet 52, the cylinder head, and the grommet 52
The heat transfer between the cylinder block and the cylinder block is improved, and thus the heat transfer from the cylinder head to the cylinder block can be improved.

Although not described with reference to the drawings,
An embodiment in which the configuration of the fourth embodiment is implemented in the metal gaskets of the first to third embodiments is also conceivable. That is, for example, on the contact portion 6a of the grommet 6 of the first embodiment, a large number of small holes that communicate the gap 7 with the upper and lower portions of the grommet 6 are provided. According to this configuration, heat transfer between the contact surface of the cylinder block 10 and the contact surface of the cylinder head 20 is performed not only on the gasket base material 2 but also on the entire contact surface of the gasket 1 including the grommet 6. The compound 8 is provided, and the effect of improving heat transfer from the cylinder head 20 to the cylinder block 10 is further improved as compared with the case of the first embodiment.

Even when the heat transfer compound is applied to both surfaces of a normal gasket and then the gasket is sandwiched between the cylinder block and the cylinder head to assemble the engine, the same heat transfer improvement as described above is achieved. The effect is obtained. However, by adopting the configurations shown in the first to fourth embodiments, the engine assembling process is simplified, the quality is stable, and various effects can be obtained.

[0030]

As described above, according to the present invention, the minute space portion formed between the cylinder head gasket, the cylinder block and the metal contact surface of the cylinder head is filled with the heat conductive compound having good heat transfer characteristics, Since the heat transfer between the head and the cylinder head gasket or between the cylinder block and the cylinder head gasket is improved, the heat transfer from the cylinder head to the cylinder block can be improved as compared with the conventional case. As a result, cooling of the combustion chamber provided in the cylinder head is promoted, knocking is improved, and the compression ratio can be further improved. As a result, engine output can be increased and fuel consumption can be reduced.

[Brief description of drawings]

FIG. 1 is a first cylinder head gasket according to the present invention.
It is a top view of an example.

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

FIG. 3 is a cross-sectional view showing a mounted state of the cylinder head gasket in FIG.

FIG. 4 is a second part of the cylinder head gasket according to the present invention.
It is a top view of an example.

5 is a cross-sectional view taken along the line VV in FIG.

6 is an enlarged perspective view of an inner peripheral edge portion in a state in which a grommet in FIG. 5 is removed.

FIG. 7 is a third cylinder head gasket according to the present invention.
It is a perspective view of an Example.

8 is a cross-sectional view taken along the line VIII-VIII in FIG.

FIG. 9 is a fourth cylinder head gasket according to the present invention.
It is a top view of an example.

10 is a cross-sectional view taken along the line XX in FIG.

[Explanation of symbols]

 1, 30, 40, 50 Cylinder head gasket 2, 31, 41, 51 Gasket base material 2a, 31a, 51a Inner peripheral edge portion 3 Opening portion 6, 32, 42, 52 Grommet 6a, 32a, 42a, 52a Contact portion 7, 33, 44, 53 Gap 8, 34, 45, 54 Heat transfer compound 10 Cylinder block 20 Cylinder head 21 Combustion chamber 52b Small hole

Claims (1)

[Claims] 1. A cylinder head gasket having a metal portion interposed between a cylinder head and a cylinder block, the metal portion being in contact with the cylinder head or the cylinder block, wherein at least the cylinder head and the cylinder are included in the metal portion. A cylinder head gasket, characterized in that a heat conductive compound is applied to a surface of the metal portion which is in contact with either one of the blocks.