JPH09250639A - Cylinder head gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head gasket which can contribute to a high performance of an engine by reducing a bore deformation generated by a bolt fastening force around the bore. SOLUTION: When a large surface pressure is given to the position where bolt holes are provided; in a gasket 1 arranging spacers 6, a large surface pressure is given to the positions where the spacers 6 are arranged through the spacers 6, and as a result, a force to swell the bore inner wall surfaces is operated to those positions, and it suppresses the force to swell the bore inner wall surfaces at the positions 4 arranged with the bolt holes 5. Consequently, a bore deformation generated by the bolt fastening force around bore holes 4 is reduced, and the bore holes 4 are made in the form almost the same as a complete round.

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 a cylinder head and a cylinder block, and more particularly to a cylinder head gasket that reduces deformation of a bore formed in the block.

[0002]

2. Description of the Related Art A cylinder head gasket is interposed between a cylinder head and a cylinder block and is fixed by a plurality of bolts including bolts arranged around the bore of the block. In this case, in the portion around the bore where the bolt is arranged, a large surface pressure is applied from the bolt, and there is a portion where a convex portion bulging from the inner wall surface is formed on the inner wall surface of the bore of the portion. Therefore, in a certain type of gasket, for the specific bolt hole among the bolt holes arranged around the bore hole of the gasket body, the measure shown in FIG. Based on the above, the deformation of the bore or the deformation of the cylinder liner when the cylinder liner is arranged in the bore (hereinafter, referred to as "bore deformation") is reduced. However, if such deformation occurs, it causes increased oil consumption, outflow of blow-by gas, or wear of the bore and cylinder liner.
This is an obstacle to achieving high engine performance. By the way, the gasket 10 shown in the figure is formed by laminating the main body 10a of the thin metal plates 11 and 12, and has a plurality of bolt holes 14 formed around the bore hole 13.
Among them, a semicircular spacer 15 is arranged around a specific bolt hole 14a. By taking such a measure, the above-mentioned bore deformation is reduced.

[0003]

However, in a gasket formed by taking such measures, when the bore deformation exhibits a secondary deformation, that is, the line connecting the centers of the specific bolt holes as described above is used. When it is transformed into an elliptical shape (13b in FIG. 4) with the long axis (13a in FIG. 4),
It is considered effective to dispose the above spacers around these bolt holes and increase the surface pressure around the bolt holes to reduce the elliptical bore deformation. An order analysis using, for example, in the deformation of the bore manufactured to a certain engine specification, rather than the above-mentioned secondary deformation, appears.
In some cases, a third-order deformation having a triangular shape and a higher-order deformation having a square or pentagonal shape may appear, and in such a case, the above measures cannot be said to be effective. The cause of such higher-order deformation depends on the hole diameter and depth of the bolts arranged around the bore of the block, the position and the magnitude of the bolt tightening force, and the form of the water jacket formed on the block. Needless to say, the characteristics of the gasket, namely,
It depends on whether it has a laminated structure or a so-called metal core structure, and whether or not it has high compressibility and creep resistance capable of withstanding the above bolt tightening force. Therefore, the characteristics of the gasket have a considerable influence on the bore deformation.

In view of this fact, the object of the present invention is to pay attention to the characteristics of the gasket, particularly the gasket structure, and to reduce the bore deformation caused by the bolt tightening force around the bore to contribute to the high performance of the engine. To provide a gasket. It is another object of the present invention to provide a cylinder head gasket that can take measures according to the amount of strain around each bolt hole to further reduce bore deformation and contribute to higher engine performance.

[0005]

In order to solve the above-mentioned problems, the cylinder head gasket of the present invention has a structure in which each bolt is provided between bolt holes formed corresponding to the bolts arranged around the bore of the cylinder block. A spacer is provided along the line that connects the center of the hole, and the thickness of the part where this spacer is arranged is made thicker than the thickness of the gasket body. A spacer is provided along the line connecting the centers of the bolt holes other than the bolt holes located between them, and the thickness of the portion where the spacer is arranged is made thicker than the thickness of the gasket body. is there.
With such a structure, it can be applied to any gasket regardless of the characteristics of the gasket, that is, whether it has a laminated structure or a metal core structure. If the spacer has a laminated structure, the spacer provided between the laminated layers, and if it has a metal core structure, the spacer provided on the outermost surface thereof is made of a material having high compressibility and creep resistance. For example, it may be made of metal, resin or rubber. Further, the shape of the spacer is not particularly limited as long as it has an appropriate width along the line connecting the centers of the bolt holes and can reduce the bore deformation as a result.

As described above, the spacers are provided at the portions along the line connecting the centers of the bolt holes, and the thickness of the portions where the spacers are arranged is made thicker than the thickness of the gasket main body, whereby the bolts around the bore are arranged. Even if a large surface pressure is applied to the site and a force for bulging the inner wall surface acts on the inner wall surface of the bore of this site, the large surface pressure is also applied to the site where the spacer is arranged. for that reason,
A force that bulges this inner wall surface acts on the inner wall surface of the bore where the spacer is arranged, and this suppresses the force that bulges the inner wall surface of the bore where the bolt is arranged. Reduces bore deformation caused by force. By the way, as a general rule, a spacer is provided along the line connecting the centers of the bolt holes of the gasket so that a large surface pressure is applied to this region.
In some types of engines, a large surface pressure may be applied to the portion of the bolts arranged around the bore along the line connecting the centers of the bolts located at the end of the block. Since a force for bulging the inner wall surface of this portion acts on the inner wall surface of the bore, it is not sufficient to dispose the spacer at this portion. In addition, in the portion along the line connecting the centers of the bolts located between the adjacent bores, the force for bulging the inner wall surface of the bore in the portion where the bolts are arranged is applied to each inner wall surface of the adjacent bores. It may be dispersed, and even in such a case, it is not enough to intentionally dispose the spacer.

In order to solve the above-mentioned problems, the cylinder head gasket of the present invention is such that when the thickness of the portion where the spacer is arranged is made thicker than the thickness of the gasket main body, the bolt surrounding force generated by the tightening force of the bolt is generated. It is made thicker by an amount corresponding to the amount of strain. That is, the thickness of the gasket body is generally 1.2
On the other hand, the strain amount around this bolt generated by the tightening force of the bolt, that is, the strain amount of the block plus the strain amount of the gasket is 0.01-
Since the thickness of the spacer is 0.3 m / m, a spacer having a thickness corresponding to this size is used, but usually 0.1 to 0.2.
It is set at m / m. However, since the strain amount is not uniform, it is preferable to dispose a spacer having a thickness corresponding to the strain amount because the bore deformation can be further reduced.

[0008]

FIG. 1 shows an example of an embodiment of the present invention.
This will be described with reference to FIG. The cylinder head gasket 1 according to the present embodiment is interposed between the cylinder head 2 and the cylinder block 3, and is bored corresponding to a bore (not shown) of the block 3 and bolts arranged around the bore. It has holes 4 and bolt holes 5, respectively. Then, the gasket body 1a is provided with three bore holes 4, bolt holes 5 are formed around the bore holes 4 at equal intervals, and bolts located between the adjacent bore holes 4 are formed. The holes 5a are formed so as to overlap between the bore holes 4. Of the bolt holes 5 thus formed, the bolt holes 5a located between the bore holes 4
As shown in FIG. 1, a rectangular shape having an appropriate size is formed at a portion along the line connecting the center of the bolt hole 5a and the center of the bolt hole 5b, etc. A metal spacer 6 is provided.

The spacer 6 is arranged so that its center line coincides with the line connecting the centers of the bolt holes 5a and 5b, etc., and, as in the present embodiment, the gasket body. If the gasket 1a has a laminated structure, it is arranged between the metal thin plates 7 and 8 constituting the gasket body 1a. In this case, the thickness B of the portion where the spacer 6 is arranged is made thicker than the thickness C of the gasket body 1a, and the thickness of the spacer 6 is set to 0.1 to 0.2 m / m. By the way, the shape of the spacer 6 is not particularly limited as long as it has an appropriate width along the line connecting the centers of the predetermined bolt holes 5 and can reduce the bore deformation as a result. For example, spacers 6a and 6 as shown in FIG.
It may be in the shape of b.

Next, the gasket 1 having such a structure
The mechanism by which the deformation of the bore is reduced will be described with reference to FIG. By the way, in the case where the spacer 6 is not arranged, when a large surface pressure is applied to the portion around the bore hole 4 where the bolt hole 5 is arranged, the inner wall surface bulges with respect to the inner wall surface of this bore. The force exerted causes the bore to undergo a bore deformation exhibiting a higher-order deformation as shown by a two-dot chain line in FIG. However, in the gasket 1 in which the spacers 6 are arranged as in this embodiment, the bolt holes 5 (5a, 5b,
When a large surface pressure is applied to a portion where 5c etc. are arranged, a large surface pressure is also applied to the portion where the spacer 6 is arranged via the spacer 6, so that also in this portion, The force that bulges the inner wall surface of the bore acts,
This suppresses the force of bulging the inner wall surface of the bore in the portion where the bolt hole 5 is arranged, and as a result, the bore deformation caused by the bolt tightening force around the bore hole 4 is reduced, and the bore is
The shape is substantially the same as a perfect circle as shown by the solid line in FIG.

By the way, in the engine using the gasket 1 according to the present embodiment, among the bolt holes 5 arranged around the bore hole 4, for example, the center of each bolt hole 5a located between the adjacent bore holes 4 is located. Part 1b along the line connecting
In the above, since the force for bulging the inner wall surface of the bore at the portion where the bolt holes 5a are arranged is dispersed to the inner wall surfaces of the adjacent bores and becomes small, it is not necessary to dispose the spacer 6. . Incidentally, in some types of engines,
A large surface pressure is applied to the portion 1c located at the end of the block 3 along, for example, a line connecting the centers of the bolt holes 5c without arranging the spacer 6, and a force for bulging the inner wall surface of the bore. May work. In such a case, it is not necessary to dispose the spacer 6 at this portion 1c for the purpose of reducing the deformation of the bore.

[0012]

According to the cylinder head gasket of the present invention, it is possible to reduce the deformation of the bore provided in the block due to the tightening force of the bolts arranged around the bore, thereby contributing to the high performance of the engine. it can. Further, according to the cylinder head gasket of the present invention, it is possible to further reduce the deformation of the bore by taking measures according to the amount of strain around each bolt hole and contribute to the high performance of the engine.

[Brief description of drawings]

FIG. 1 is a plan view of a cylinder head gasket according to the present embodiment and an AA enlarged cross-sectional view in the plan view.

FIG. 2 is a partially enlarged cross-sectional view of various spacer shapes provided on the present gasket.

FIG. 3 is an explanatory view for explaining a mechanism for reducing a bore deformation by the gasket of FIG.

FIG. 4 is a plan view of a conventional cylinder head gasket and an enlarged sectional view taken along line A1-A1 in the plan view.

[Explanation of symbols]

 1 Cylinder Head Gasket 1a Gasket Body 4 Bore Hole 5 (5a, 5b, 5c) Bolt Hole 6 Spacer B Thickness of Spacer Spacer C Thickness of Gasket Body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Ishii 12-21 9-12, Yachiyo Taipei, Yachiyo-shi, Chiba Leopalace Yachiyodai 13-205

Claims (2)

[Claims] 1. A cylinder head gasket having a bore of a cylinder block and a bore hole and a bolt hole formed corresponding to bolts arranged around the bore, respectively, wherein the bolt hole of the gasket body is: At least a spacer is provided at a portion along the line connecting the centers of the bolt holes other than the bolt holes located at the end of the block and the bolt holes located between the bore holes, and the thickness of the portion where the spacer is arranged is Cylinder head gasket characterized by being made thicker than the thickness of the gasket body. 2. When the thickness of the portion is made thicker than the thickness of the gasket body, the thickness is made thicker by an amount corresponding to a strain amount around the bolt hole caused by the bolt tightening force. The cylinder head gasket according to item 1.