JPH0717886Y2 - Beat plate of cylinder head gasket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a bead plate for a metal-laminated cylinder head gasket, and more specifically, a metal for preventing leakage from a liquid hole arranged around a cylinder hole. The present invention relates to a bead plate of a laminated cylinder head gasket.

[Conventional technology]

It is well known that as a cylinder head gasket, a metal gasket is used in which a bead is provided around a hole formed in a thin metal plate and the bead is compressed by a head bolt to seal the periphery of the hole.

By the way, the cylinder head gasket needs to seal liquid holes such as lubricating oil and cooling water in addition to sealing the periphery of the cylinder hole. These hole seals are
Conventionally, grommets were used for sealing, but in order to improve the sealing performance, heat resistance, etc., and reduce the number of gasket parts to increase productivity, these liquid holes are also sealed with beads. It was

In this way, if all the holes to be sealed are sealed with beads, since all the beads have the same compressive strength, the tightening force by the head bolt is dispersed and the sealing performance of the cylinder hole with the highest internal pressure is improved. There is a problem that you cannot get enough.

Therefore, in the prior art of Japanese Utility Model Laid-Open No. 60-28250, the rising angle of the bead of the cylinder hole is made more acute than the rising angle of the bead of the liquid hole to strengthen the waist of the bead and surround the circumference of the cylinder hole. The compression force is concentrated on the bead.

[Problems to be solved by the device]

By the way, the cylinder head gasket 1, as shown in FIG. 9, is interposed between the cylinder body 2 and the cylinder head 4, and is tightened with a head bolt 6 for use. In this case, although the bead plate 8 of the cylinder head gasket 1 is a thin metal plate, since carbon steel or stainless spring steel is used, the bead plate 8 has a strong elasticity and the spring force F of the bead 10 pushes the cylinder head 4 outward. . In the case of the laminated type, there is a further problem that the cylinder head 4 warps as shown in the figure because the circumference of the cylinder may be formed thicker than other portions. Therefore, there is a problem that leakage easily occurs from a liquid hole (not shown) close to the bead 10, particularly a liquid hole (not shown) surrounded by the cylinder hole and the bolt hole. This problem becomes particularly problematic in cylinder heads cast from aluminum as the engine becomes lighter in weight and has higher performance.

An object of the present invention is to provide a bead plate of a cylinder head gasket having improved sealing performance of a bead of a liquid hole arranged near a cylinder hole or in a region sandwiched between a bolt hole and a cylinder hole. There is.

[Means for Solving the Problems]

In order to achieve the above object, the bead plate of the cylinder head gasket of the present invention is composed of a thin metal plate forming the gasket, a cylinder hole, a plurality of bolt holes surrounding the cylinder hole, a water hole, and an oil hole. A bead spring that surrounds a water hole and an oil hole in which a half or more of the opening area is arranged inside the area surrounded by the area line connecting the centers of the bolt holes so as to surround all the cylinder holes. From the constant, the spring constant of the bead surrounding the water hole and the oil hole in which more than half of the opening area is arranged outside the region is made smaller.

As means for increasing the spring constant, the rising angle of the bead can be made more acute, the bead width can be made narrower, the bead plate can be made thicker, the hardness of the plate can be made larger, and these means can be appropriately used. It can be realized by means such as mixing.

The bead shape that can be used in the present invention may be a bead shape whose cross-sectional shape is arcuate, arcuate, trapezoidal, or the like, that is, a bead shape conventionally used.

The cylinder head gasket of the present invention may be a single plate gasket or a laminated gasket.

〔Example〕

Hereinafter, the present invention will be described in detail by way of examples with reference to the accompanying drawings.

1 to 3, in the bead plate 8 of the cylinder head gasket 1 of the first embodiment, bolt holes 14 are arranged around the cylinder hole 12, and water holes 16, 16 ', 18 and oil holes 20 are provided. It is provided at a predetermined position. By the way, the water hole 16 is an area line 22 that connects the adjacent bolt holes 14 so as to surround all the cylinder holes 12.
Is located in a region sandwiched between the cylinder hole 12 and the two cylinder holes 12, and the water hole 16 'is a portion sandwiched between the cylinder hole 12 and the bolt hole 14 and is more than half of the water hole 16', in this case. Most are located within the region line 22. Beads in each cylinder hole 12
A bead 24 is provided in the water holes 16 and 16 ', and a bead 26 is provided in the water hole 18 and the oil hole 20 which are substantially outside the area line 22.

Then, by stacking the auxiliary plates 28 thinner than the others, each bead 1
Make sure that 0,24,26 are not completely compressed and face plate 3 on the outside
0 and 32 are arranged. The surface plate 30 had a thickness of 0.3 mm, and the surface plate 32 and the bead plate 8 had a thickness of 0.2 mm. The beads 10, 24, 26 have the same height, and the bead width W ₂₄ of the bead 24 is the same as that of the other beads 10, _26.
The width was smaller than the beebo width W ₂₆ (W ₂₄ <W ₂₆ ). Also,
Grommet plate 3 around water holes 16, 16 ', 18 and oil hole 20
Covering with 4 (Figs. 2 and 3, but the oil hole 20 is not shown), around the cylinder hole 12, the face plate 30 is folded back and overlapped with the other face plate 32 (Fig. 3). The flange portion 36 is formed so that the sealing fluid does not enter the respective laminated portions and the compression height of the bead 10 is made higher than that of the other beads 24 and 26 so that the compression force becomes stronger.

Next, the operation of the beads 10, 24, 26 will be described with reference to FIG. 4 showing the relationship between load and strain. The symbols attached to the respective curves in the figure indicate the corresponding beads. When the beads 10, 24, 26 are compressed, they change in the direction of the upward arrow, and the load increases until the height after compression reaches the thickness of the auxiliary plate 28. During that time, the beads 10, 24, 26 are partly plastically deformed, so when the load is removed, the beads 10, 24, 26 change in the direction of the downward arrow, and permanent set remains at zero load. Then, the bead 24 having a large spring constant can obtain a larger load than the bead 26 having a small spring constant even at the same compression height, and the sealing force increases accordingly. The bead 10 that seals the cylinder hole 12 has a smaller spring constant than the bead 24. However, by compressing the face plates 30 from both sides, the compression height can be increased and a large load can be obtained.

The cylinder head gasket 1 of the first embodiment described above
Does not leak from the water holes 16 and 16 'arranged near the cylinder hole 12, and the cylinder hole 12, water holes 16, 16' and 18, oil holes
It was confirmed that the performance of sealing each of the 20 was well balanced. Further, the cylinder head gasket 1 can suppress the occurrence of cracks in the metal plate caused by flapping due to combustion pulsation pressure of the engine. Also,
The bead plate 8 of Example 1 can also be used as a single plate gasket.

FIG. 5 corresponds to FIG. 3 of the above-mentioned embodiment and corresponds to the cylinder hole 12
This is a modified example in which the compressed height of the bead 10 around it is made higher than the compressed height of the bead 24 around the water holes 16 and 16 ', and the auxiliary plate 28 is hung on the bead 10 to form the bead 10 and the bead 24. The compression height of is changed.

The second embodiment will be described with reference to FIGS. 6 and 7. In addition,
FIG. 6 is a sectional view of a portion corresponding to FIG. 2 and FIG. 7 is a sectional view of a portion corresponding to FIG. In the second embodiment, the bead plate 8 provided with the beads 10 and the beads 24, 2 are used.
The bead plate 38 provided with 6 is used as a separate plate to change the hardness of the plate material to increase the spring constant of the bead 10, and the width of the bead 24 is made narrower than the width of the bead 26 to increase the spring constant. is there. The same results as in Example 1 were obtained in Example 2 as well.

FIG. 8 shows Embodiment 3 in which the spring constant of the bead 24 of the cylinder head gasket 1 is changed by changing the bead plate thickness and the bead width as means for increasing the spring constant of the bead 26. That is, the bead 24 is formed on the bead plate 8 and the bead 26 is formed on the bead plate 40 thinner than that. Cylinder head gasket 1 of Example 3
Also, as in Example 1, the metal plate was not cracked due to flapping due to the combustion pulsation pressure.

[Effect of device]

As described above, the bead plate of the cylinder head gasket of the present invention forms a cylinder hole, a plurality of bolt holes surrounding the cylinder hole, a water hole, and an oil hole in the thin metal plate forming the gasket. From the spring constant of the bead that surrounds the perimeter of the water and oil holes, where more than half of the opening area is located inside the area enclosed by the area line that connects the center of the bolt holes so as to surround all cylinder holes, the area Since the spring constant of the bead surrounding the water hole and the oil hole, which has more than half of the opening area outside, was reduced, the bead spring force around the cylinder hole applied to the cylinder head when tightening with the head bolt. Even if a warp occurs, the reduction of the seal surface pressure due to the warp is likely to occur, and the water hole and the oil hole in which more than half of the opening area is arranged inside the area surrounded by the area line Can hold Lumpur performance, it is possible to prevent leakage of coolant or lubricant.

Further, in the bead plate of the metal laminated cylinder head gasket of the present invention, the spring constant of the bead is adjusted by the relative position of each liquid hole to the cylinder hole and the bolt hole, so that the leakage caused by the flapping of the cylinder head due to the combustion pulsation pressure. , Can prevent the metal plate from cracking and maintain the liquid hole sealing performance for long-term use,
The reliability of the cylinder head gasket can be improved.

[Brief description of drawings]

1 is a plan view of a bead plate of the present invention according to Embodiment 1, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is III of FIG.
-III line sectional view, FIG. 4 is a graph for explaining the operation of the embodiment shown in FIGS. 1 to 3, FIG. 5 is a sectional view showing a modification of the embodiment 1, and FIGS. FIG. 8 is a partial cross-sectional view of the second embodiment, FIG. 8 is a partial cross-sectional view of the third embodiment, and FIG. 9 is a cross-sectional view for explaining the problems of the conventional cylinder head gasket. 1 …… Cylinder head gasket, 8,38,40 …… Bead plate, 10,24,26 …… Bead, 12 …… Cylinder hole, 14 …… Bolt hole, 16,16 ′, 18 …… Water hole, 20 …… Oil hole, 22 ……
Area line, 30, 32 ... Surface plate.

Claims (1)

[Scope of utility model registration request] 1. A cylinder hole, a plurality of bolt holes surrounding the cylinder hole, a water hole and an oil hole are formed in a thin metal plate forming a gasket, and the center of the bolt hole surrounds all the cylinder holes. As the spring constant of the bead surrounding the water hole and the oil hole in which more than half of the opening area is placed inside the area surrounded by the connecting area line, more than half of the opening area is placed outside the area. A bead plate for a cylinder head gasket in which the spring constant of the bead surrounding the water hole and oil hole is reduced.