JPS59113372A - Gasket for cylinder head - Google Patents

Abstract

PURPOSE:To maintain an excellent sealing performance, by coating both the sides of a metal sheet with a thin layer of an asbestus-rubber mixture to manufacture a gasket and by providing protrusions around the water and oil holes of the gasket. CONSTITUTION:A thin layer 14 is made of a mixture of asbestus and rubber to coat both the sides of a metal sheet 13 such as a steel sheet to manufacture a gasket 12. Protrusions 19 are provided around the water and oil holes 16 of the gasket 12. When a very strong force acts to the part of the gasket fitted with a grommet 18, the compressive elastic limit is exceeded only in the coating layer 14. For that reason, the sealing stress does not decrease and the sealed clearance does not increase. Since the area of contact with a cylinder head and a cylinder block is limited, enough contact pressure is obtained around the water and oil holes 16. As a result, an excellent stable gas-sealing function is maintained.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a cylinder head (hereinafter simply referred to as a head) and a cylinder block (hereinafter simply referred to as a block) that are connected to a cylinder via an IJ. Regarding head gaskets.

[Prior art]

In recent years, engines have tended to have higher horsepower and higher rotation speeds, and this trend has led to an increase in combustion pressure and thermal load.
It's like k. At the same time, in recent years there has been a trend toward lighter engine engines, and this trend has led to a decrease in the rigidity of heads and blocks.

For this reason, the combustion pressure in the head and block is
:ru47. j Architectural deformation and thermal 9? The thermal deformation in iii is 1 times larger.

FIG. 1 shows the movement of the head and block due to the structural deformation. In this figure, 1 is the head, 2 is the cylinder head gasket, 3 is the block, arrow A is the expansion of the cylinder bore due to combustion pressure, arrow B is the movement of head 1 due to combustion pressure, and arrow C is Bolt due to combustion pressure (take head 1 to block 3)
The stress on the bolt (not shown), the increase in the gap between the head 1 and the block 3, and the decrease in the sealing stress, arrow 1] do not indicate movement of the head surface, respectively.

On the other hand, Fig. 2 shows the thermal deformation of the head 1 and block 3, where arrow E shows the vertical change in the seal gap, arrow F shows the horizontal movement of the gasket 2, and arrow G shows the change in the cylinder. Thermal expansion, T1 indicates the deflection of the head surface.

Under such environmental conditions, the cylinder head
The gasket will be in dynamic contact with the head and block rather than simply statically. Therefore, the environmental conditions are extremely harsh.

However, in the past, cylinder head gaskets, such as the one illustrated in FIG. 1, have been commonly used, which are made by pressing sheet materials of non-metallic material onto both sides of a steel plate. 1st
To explain in more detail the structure of the conventional cylinder head gasket shown in the figure, the gasket body 4 has claws 5 on both sides.
It consists of a steel plate 6 which has been punched out, and a sheet material 7 that is crimped onto both sides of the steel plate 6, and the sheets 1 to 7 are made of a mixture of rubber and asbestos. In the gasket body 4, a grommet 9 is provided around the cylinder hole 8 for sealing combustion gas in the cylinder of the engine.
are attached so as to sandwich both sides of the peripheral portion.

In addition, the water hole or oil hole 1 of the gasket body 4
A liquid gasket 11 is applied around 0 (
Note that a rubber ring may be fitted into the water hole or oil hole 10).

In such a conventional cylinder bed gasket, (a) If a large stress is applied to the grommet 9 attachment part,
Since the sheet material 7 exceeds the compression elastic limit, the sixth
As shown by the curve P in the figure, τ of the entire GOOMET 9 mounting portion also exceeds the compressive elastic limit. As a result, the sealing stress decreases, the sealing gap widens, and gas leakage and grommet 9 breakage tend to occur.

(b) Due to the application of a large thermal load, the sheet material 7 tends to creep in the grommet 9 mounting portion, which also tends to cause gas leakage.

(c) The areas around the water hole a3 and the oil hole 10 tend to be poorly sealed, so the liquid gasket 11 was applied or a rubber ring was attached as described above. This work is time-consuming and reduces the productivity of cylinder heads and gaskets. In addition, liquid gasket 1
1, it is not always possible to obtain a satisfactory sealing effect.

(d) In order to ensure a 4-minute seal around the water and oil holes 10, if the bolts are tightened with a large force, an excessive load will be applied to the sheet material 7 around the bolt, causing compression. The elastic limit will be exceeded and the gasket body 4 will be destroyed.

There were various drawbacks such as.

Furthermore, in recent years, gas guts in which both sides of a steel plate are coated with a thin layer of simple rubber have come to be used as gaskets other than cylinder head gaskets.

However, in this type of conventional gasket, when the rigidity of the joint surface such as a flange is small or when the tightening force is large, the rubber layer exceeds the compressive elastic limit and flows sideways, resulting in 1. It was increasing. Also,
Concomitantly, thermal deformation or structural deformation (deformation not based on thermal loads) of the joint surfaces increases, which can lead to leakage. Furthermore, the layer coated on the steel plate is rubber! Since there are 11 layers, the heat-resistant warm stone limit is normally 150'cf2 degrees, and there was also the drawback that it could not be used in a high-grade environment.

(Object of the invention) The present invention has been made in view of the above circumstances, and
It is possible to maintain stable and excellent gas sealing performance even under harsh environmental conditions where extremely large thermal loads are applied. It is an object of the present invention to provide a cylinder head gasket that can maintain good sealing around c6 and oil holes, and can improve productivity.

(Invention 11-1) A cylinder head gasket according to the present invention that achieves the above-mentioned object includes a thin layer made of a mixture of a compressible fiber such as asbestos and an elastomer such as rubber on a metal plate. A gasket body formed by a coating, a water hole, an oil hole, and a cylinder hole penetrated through the gasket body, and a gasket body formed by press working so as to surround the water hole and the oil hole. and a metal grommet attached to the periphery of the cylinder hole in the gasket body.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on examples not shown in the drawings.

4 and 5 show an embodiment of the present invention. In this embodiment, the gasket body 12 includes a metal plate 13 such as a steel plate, and a thin layer (hereinafter referred to as a coating material layer) 1 made of a mixture of asbestos and rubber coated on both sides of the metal plate 13.
It consists of 4. Here, the thickness of the covering material layer 14 is, for example, about 150 to 200 μm on one side.

The gasket body 12 is penetrated by a cylinder hole 15, a water hole 16 through which cooling water passes, and an oil hole 17 through which lubricating oil passes. Grommets 18 made of metal such as stainless steel are fitted around the cylinder hole 15 in the gasket body 12 so as to sandwich both sides of the peripheral portion. In addition, in the parts around the water hole 16 and the oil hole 17 of the gasket body 12, there are provided annular holes having an arcuate cross section and an annular shape when viewed from above, so as to surround the peripheries of these holes 16 and 17, respectively. The protrusions 19 and 20 are formed by press working (
Note that the cross section of the protrusion 19 is shown in FIG.
The cross-sectional shape of the protrusion 19 is also exactly the same as that of the protrusion 19).

The mixing ratio of rubber and asbestos in the covering material layer 14 is preferably, for example, 5 parts of asbestos or more for 1 part of rubber, and if the ratio of asbestos becomes smaller than that, When protrusions 19 and 20 were machined,
The ita layer 14 is damaged by υ1. The most preferable mixing ratio of rubber and asbestos is 7 parts of asbestos to 1 part of rubber.
! This is a trace of the Fw part.

In this cylinder head gasket, the nonmetallic material present in the grommet 18 mounting portion is removed from the coating material layer 14.
The other parts of the grommet 18 mounting portion (grommet 18-3 and metal plate 13) are all made of metal.

Therefore, even if a very large stress is applied to the grommet 18 attachment part, only the covering material layer 14 will exceed the compression elastic limit.
Since the coating material layer 14 is a thin layer, even if the compressive elasticity limit is exceeded, the grommet attachment part 1
8. Overall, there is no substantial impact. In other words, the grommet 18 mounting portion as a whole does not exceed the compressive elastic limit even if it receives a very large stress, as shown by curve Q in FIG. Therefore, even if a very large stress is applied to the chrome fitting 18 fitting part, unlike the conventional case, the sealing stress will not be reduced, the sealing gap will be widened, and gas leakage and damage to the grommet 18 will not occur.

Furthermore, even if the sheathing material layer 14 causes creep due to a large thermal load, since the sheathing material layer 14 is a sulfur layer as described above, the effect will be less on the grommet 18 mounting portion as a whole. There is no risk of gas leakage as there is no risk of gas leakage.

Also, in this cylinder head gasket, the protrusion 1
9.20 is 8Ω, so the water hole 16 and oil Hole 17
Sufficient contact pressure can be obtained around the area. therefore,
Tighten with force to small port 1, water hole 16 and oil hole 1
7 can be sealed extremely well.

In addition, since the covering material layer 14 is not made of rubber alone but is made of a mixture of asbestos and rubber, it is assumed that the circumference of the bolt hole 21 is
Even if a large stress is concentrated in a portion, the coating material layer 14 will not exceed the compressive elastic limit and flow laterally in that portion, thereby reducing the torque holding ability.

Also, above)! Like 11? /! ! m'tA layer 14
Because it is made of a mixture of asbestos and rubber, rather than just rubber, it does not cause problems even in high-temperature environments.

Furthermore, if the metal plate 13 is covered with a layer of rubber alone, if the metal plate 13 is very thin, the protrusions 19.
20 by pressing]: However, in reality, in order to maintain the strength necessary for the cylinder head gasket, the metal plate 13 needs to have a certain thickness (for example, a steel plate). (in this case, the rubber layer is about o, amm), so if the press working is performed, the rubber layer will break. However, in this cylinder head gasket, the covering material layer 14 is not made of rubber alone, but is made of a mixture of asbestos and rubber, so if the mixing ratio is appropriately selected as described above, the protrusions 19 and 20 can be formed. , it can be formed by press working without any problem.

Since the protrusions 19 and 20 are formed by press working, compared to the conventional case where liquid gaskets are applied around the water holes and oil holes or rubber rings are attached, the cylinder The durability of the head gasket can be improved.

FIG. 7 shows another embodiment of the invention, in which the grommet 18
is attached to the wiring 22 and the gasket body 12. Note that the other configurations are the same as in the previous embodiment. (The same components as those in the 3532 case of the previous embodiment are indicated by the same reference numerals).

When the wire ring 22 is accommodated in the grommet 18 in this way, stress is concentrated on the wire ring 22.
By doing so, the contact surface 11'1 between the grommet 18 and the cylinder head gasket and block is restricted and the contact pressure can be increased, so that the gas sealing characteristics can be further improved.

In each of the above embodiments, the covering material layer is made of a mixture of asbestos and rubber, but in the present invention,
Instead of asbestos, other types of compressed fibers such as Kevlar (trade name, manufactured by DuPont) may be used, and in place of the rubber, Hakuno rod's Ex-1I may be used. I don't even do it.

〔Effect of the invention〕

As described above, in the cylinder head gasket according to the present invention, the gasket body is constructed by coating both surfaces of a metal plate with a thin layer of a mixture of compressible fibers such as asbestos and a lastomer such as rubber. Circumference of cylinder hole of main body)
By attaching a metal grommet to the 9th part and forming protrusions surrounding the water and oil holes by press working, (a) the grommet can be attached even if a very large stress is applied to the grommet attachment part. Since the group as a whole does not exceed the compressive elastic limit, the sealing stress does not decrease, the sealing gap widens, and gas leakage and damage to the grommets 1 to 1 are not caused as in the conventional case.

(B) Even if the coating material layer creeps due to a large heat load, the grommet installation group as a whole will not be affected by the above effect, so no gas leaks will occur. .

(c) By providing the protrusions, a sufficient amount of contact pressure can be obtained around the water hole and oil hole, so when tightening a small bolt, the area around the water hole and oil hole can be extremely tightened. Can be sealed well.

(D) The rd4A layer is not made of elastomer alone, but is made of a mixture of compressible fibers and elastomer, so even if large stress were concentrated around the bolt hole,
In this part a3, the coating material layer exceeds the compressive elastic limit and flows sideways, and the torque holding power is not reduced.

(E) As shown in above t[, since the Ti U G to be coated is not composed of a single elastomer but a mixture of compressible fibers and an elastomer, no trouble will occur even in the environment of descendants.

(f) As mentioned above, since the covering material layer is not made of a single elastomer but a mixture of compressible fibers and an elastomer, the protrusions can be formed by press working without any problem.

(g) By forming the protrusions by press working, there is no need to apply liquid gasket around the water hole and oil hole or to install a rim ring, so the cylinder head gasket productivity can be improved.

It is possible to obtain excellent effects such as.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the movement of the head and block cock due to combustion pressure, Figure 2 is an explanatory diagram showing the thermal deformation of the head and block, and Figure 3 is a cross-sectional view of a conventional cylinder head gasket. FIG. 4 shows a cylinder according to the present invention.
FIG. 5 is a plan view showing an embodiment of the head gasket, FIG. 5 is a cross-sectional view taken along the line v-v in FIG. 4, and FIG. 6 is the conventional cylinder head gasket shown in FIG. A compressive stress-strain diagram showing the relationship between compressive stress and strain of the mounting portion, and FIG. 7 is a sectional view showing another embodiment of the present invention. 12... Gasket body, 13... Metal plate, 14
...Covering material layer, 15...Cylinder hole, 16...Water hole, 17...Oil hole, 18...Grommet, 19.2
0... Protrusion. Patent applicant Neeling Gasket Co., Ltd. Agent
Patent Attorney Omori Car Box 1 Figure 2 Procedural Amendment May 2, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of the Case 1982 Patent Application No. 220225 2, Name of the Invention Cylinder. Head Gasket 3, Relationship with the case of the person making the amendment Patent Applicant Sushitoshi Decio NZf3 Rei 75K Address 305 Iro, Oyama-cho, Sunto-gun, Shizuoka Prefecture Name Nisan Gasket Co., Ltd. 4, Agent 7, Amendment Column 8 of Detailed Description of the Invention in the Subject Specification, Contents of Amendment 1>"Figure1" in line 10 of page 3 of the specification is corrected to "Figure 3." 2) "Fig. 1" on page 3, line 10 of the specification is corrected to "this Fig. 3 J." 3) "Thermal load" on page 4, line 16 of the specification is corrected to "thermal load." do. 4) Insert [and bolt hole 21] next to "oil hole 17" in the first line of page 8 of the specification. 5) "Thermal load J" on page 9, line 17 of the specification is corrected to "thermal load." 6) "Thermal load" on page 13, line 13 of the specification is corrected to "thermal load."

Claims (1)

[Claims] A gasket body formed by coating a metal plate with a thin layer made of a mixture of compressible It (It and J lastomer), a water hole, an oil hole and a cylinder hole penetrated through the gasket body, and the gasket body, A cylinder comprising a protrusion formed by press working to surround the water hole and the oil hole, and a metal grommet attached to the periphery of the cylinder hole in the gasket body.・Head gasket.