JPH05149434A - Metallic gasket - Google Patents

Abstract

PURPOSE:To secure a stable sealing property along the whole surface of fluid holes by providing a metallic ring and a seal member at the adequate positions, in a metallic gasket in which at least two sheets of substrates are provided opposing the tops of their beads each other. CONSTITUTION:Fluid holes 11 and 21 through which a pressure fluid pass are formed, and two sheets of metallic substrates 10 and 20 on which beads 13 and 23 are formed respectively are provided around the fluid holes 11 and 21. While a metallic ring 14 is welded between the inner periphery at the projecting side of the bead 13 of one side substrate 10 and the fluid hole 11, a seal member 30 is provided at the outer periphery at the projecting side of the bead 23 of the other side substrate 20. The substrates 10 and 20 are arranged to oppose the tops of the beads 13 and 23 each other.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a metal gasket,
Particularly, the present invention relates to a metal gasket suitable as a cylinder head gasket of an internal combustion engine.

[0002]

2. Description of the Related Art It is well known that a gasket is interposed between joint members in order to prevent leakage of pressure fluid from the joint surface, for example, between a cylinder head and a cylinder block of an internal combustion engine. A cylinder head gasket is installed. Regarding this type of gasket, recently, a metal gasket made of a metal plate material has been receiving attention.
For example, a metal substrate is provided with a fluid hole through which a pressure fluid such as combustion gas passes, and a bead is formed around the fluid hole so that a high surface pressure can be secured to the joining member. Are known.

Regarding the above-mentioned metal gasket, for example, as disclosed in Japanese Utility Model Laid-Open No. 59-188955, in order to prevent the bead from being plastically deformed by the tightening force and the sealing property being deteriorated, the convex height of the bead is increased. It is proposed that a surface pressure adjusting plate made of a thinner plate is provided in a portion other than the bead. For the same purpose, various types have been proposed in which a thick portion is formed on the substrate on the hole side with respect to the bead. Regarding the thick wall portion, for example, Japanese Utility Model Laid-Open No. 61-14748 discloses a thick wall portion formed by plating, and Japanese Utility Model Laid-Open No. 2-6855 discloses a thick wall portion by adhering or welding a sub-plate. In Japanese Patent Application Laid-Open No. 64-35057, a stopper (corresponding to a thick portion) formed by thermal spraying is impregnated with a filler such as a resin to ensure a sealing function. ing. Furthermore, Shokai 6
Japanese Patent No. 4-8556 discloses a cylinder head gasket in which a thick portion is provided on the inner peripheral side of a bead and a soft seal member is provided on the base portion on the outer peripheral side.

[0004]

As the spacers for the surface pressure adjusting plate and the thick portion, the beads are adjusted so that they can be compressed and deformed to function as a sealing member, and at the same time, they can function as a sealing member themselves. It is desirable to use a material having a sealing property, and in view of assembling property, thickness control, cost, etc., it is desirable to bond the metal ring to the peripheral portion of the fluid hole of the substrate.

However, if the metal ring is joined to the substrate by welding or the like instead of the thick wall portion in the cylinder head gasket described in Japanese Utility Model Laid-Open No. 64-8556, the substrate may be distorted. Is large. As described above, it is necessary to further provide a sealing member on this substrate, but if the substrate is distorted, it is difficult to attach the sealing member to an appropriate position, and productivity is reduced.

By the way, the above-mentioned Japanese Patent Laid-Open No. 64-35057.
As shown in FIG. 6 of the publication, in a metal gasket in which two identically shaped substrates each having a bead are arranged such that their tops face each other, it is necessary to secure a desired surface pressure. In this case, the bead displacement amount of each substrate can be made smaller than that of one substrate, so that the fatigue resistance is improved.

[0007] In this publication, a stopper is formed by thermal spraying and then impregnated with a resin, which is different from the one in which a metal ring is joined in terms of its characteristics, manufacturing and assembly problems, etc. Even if the stopper in the publication is replaced with a metal ring, the seal member is formed on the outer periphery of the bead protruding side of the substrate to which the metal ring is joined, and the same problem as described above occurs when disposing the seal member. Moreover, since the intermediate plate is interposed, the amount of material is increased and the thickness as a whole is increased. On the other hand, as is clear from the fact that the publication does not disclose a configuration in which the intermediate plate is removed, it is not necessary to simply remove the intermediate plate.

In view of this, the present invention provides a metal gasket having at least two metal substrates each having a bead formed around the fluid hole, and the tops of the beads are opposed to each other. It is an object of the present invention to arrange the members at appropriate positions so as to ensure stable sealing performance over the entire circumference of the fluid hole.

[0009]

In order to achieve the above object, the present invention provides at least a metal substrate having a fluid hole through which a pressure fluid passes and a bead formed around the fluid hole. In a metal gasket having two substrates and arranging the two substrates so that the tops of the beads are opposed to each other, among the two substrates, the inner periphery of the bead protruding side of one substrate and the fluid hole A metal ring is bonded between them, and a seal member is arranged on the outer periphery of the bead protruding side of the other substrate.

In the metal gasket, the thickness of the metal ring may be smaller than the thickness of the one substrate, and the bead height of the one substrate may be at least smaller than the thickness of the metal ring.

[0011]

When the metal gasket having the above structure is interposed between the facing joining members, for example, between the cylinder head and the cylinder block, and both are fastened with a predetermined tightening force, two substrates are formed. Of the beads are compressed and deformed, and the elastic restoring force of the compressed and deformed beads ensures a predetermined surface pressure on the joining member. In this case, since the metal ring is joined between the inner circumference of the bead on the protruding side of one of the substrates and the fluid hole, the total height of both beads is deformed until it becomes equal to the thickness of the metal ring, The subsequent deformation is prevented, the fatigue resistance of the bead is secured, and the sealing function of the metal ring itself is obtained.

[0012]

Embodiments of the metal gasket of the present invention will be described below with reference to the drawings. As the metal gasket targeted by the present invention, a cylinder head gasket interposed between a cylinder head and a cylinder block of a multi-cylinder internal combustion engine is suitable, and a metal used as the cylinder head gasket as an example. The gasket will be described.

FIG. 1 shows a cross section of one embodiment of the present invention. The metal gasket of this embodiment is formed of an elastic metal plate, for example, a stainless steel plate (SUS), and has a planar first substrate shown in FIG. 10 and the second substrate 20 having a planar shape shown in FIG. 4, and the first and second substrates 10 and 20.
A plurality of combustion chamber holes 11 and 21 are formed in each of the above. A plurality of cooling water holes 17, 27 and lubricating oil holes 18, 28 are formed in the first and second substrates 10, 20, respectively, and a plurality of bolt holes are formed around the combustion chamber holes 11, 21. 12,
22 is drilled. For example, a total of ten bolt holes 12 and 22 are formed around the combustion chamber holes 11 and 21 at substantially equal intervals. Further, the first and second substrates 10,
20 are joined to each other by caulking holes 19 and 2 at the outer peripheral ends.
9 is provided.

The combustion chamber holes 11 and 21 have a number of holes corresponding to the number of cylinders (for example, four holes for an in-line four-cylinder internal combustion engine) arranged in a straight line, and the combustion chamber holes 11 and 21 are surrounded by the holes. Beads 13 and 23 are formed. Bead 13,2
The widths of 3 are formed uniformly over the entire circumference of the combustion chamber holes 11 and 21, but the combustion chamber holes 11 and 11 that are adjacent to each other are formed.
Beads 13, 13 (2 formed around (22, 22)
The width of the collecting portion of (3, 23) is set to be smaller than the width of each of the beads to be collected.

Then, on a flat surface from the inner periphery of the protruding side of the bead 13 of the first substrate 10 to the combustion chamber hole 11, a metal ring of a perfect circle having a predetermined width, for example, a spacer made of a stainless steel plate, a so-called shim ring 14 is formed. Are joined. That is, the shim ring 14 is set to have a predetermined width sufficient to ensure the sealing function by itself, and the thickness Ts thereof is as shown in FIG.
As shown in, the thickness is set to be smaller than the thickness Tp of the first substrate 10 and larger than the height Tb of the bead 13 (that is, Tp.
>Ts> Tb). And the shim ring 14
Is welded to the first substrate 10 substantially continuously over the entire circumference by, for example, a laser welding machine, and the annular shim ring 14 is used.
A continuous welded portion 15 (not shown in FIG. 3) is formed on the entire circumference of the.

In the present embodiment, the height of the bead 23 is also set to be substantially the same as the height of the bead 13, and the total height 2Tb of both is set to be larger than the thickness Ts of the shim ring 14, but the bead The total height of 13, 23 is Shim ring 1
If the thickness is larger than the thickness Ts of 4, they may have different heights. Also, the bolt holes 12 and 22 and the lubricating oil holes 18 and 2
Beads 16 and 26 are formed around the periphery of the first substrate 8 and around the outer periphery of the first and second substrates 10 and 20. Since these beads 16 and 26 are composed of stepped portions or inclined portions and have a half shape of the beads 13 and 23, they are called half beads.

A seal member 30 made of vulcanized fluorinated rubber is provided on the outer circumference of the bead 23 of the second substrate 20 so as to be continuous over the entire circumference of the bead 23. The sealing member 30 can be formed by adding a vulcanizing agent to a fluorine-based non-vulcanized rubber, applying the vulcanizing agent on the second substrate 20, and then heating the vulcanizing agent at a predetermined temperature for vulcanization. Further, in order to secure the sealing property when joining the cylinder head 3 and the cylinder block 4 which will be described later, the sealing member 30 and the second
An unvulcanized or unvulcanized rubber layer may be formed on the entire surface of the substrate 20. Here, the non-vulcanized rubber refers to one that does not contain a vulcanizing agent, and the unvulcanized rubber refers to one that contains a vulcanizing agent but has not been vulcanized.
Therefore, although the unvulcanized rubber initially has the same characteristics as the unvulcanized rubber, vulcanization progresses during use and a strong rubber layer is formed.

The first and second substrates 10 and 20 formed as described above and shown in FIGS. 3 and 4 are arranged so that the tops of the beads 13 and 23 face each other as shown in FIG. The metal gasket is formed by caulking and joining via the caulking holes 19 and 29.

The metal gasket having the above structure is interposed between the cylinder head 3 and the cylinder block 4, and fastening bolts (not shown) are inserted into the bolt holes 12 and 22, respectively. Although the second substrate 20 is arranged on the cylinder block 4 side in the present embodiment, the first substrate 10 may be arranged on the cylinder block 4 side.

When a tightening force is applied between the cylinder head 3 and the cylinder block 4, the first and second substrates 1
The beads 13 and 23 of 0 and 20 are compressed and deformed. At this time, the total height 2Tb of the beads 13 and 23 is the shim ring 1
Since the bead 13 or 23 is thicker than the thickness Ts of No. 4, the beads 13 and 23 can be deformed until they become substantially equal to the thickness Ts of the shim ring 14, but they are not further deformed.

That is, as shown in FIG. 2, the cylinder head 3
The space between the cylinder block 4 and the cylinder block 4 is tightened, and the shim ring 14
When the bead 13 is compressed, the beads 13 and 23 are not further deformed, and the elastic restoring force causes the first substrate 10 and the second substrate 20 to move to the cylinder head 3 and the cylinder block 4, respectively. It will come into close contact. Further, since the seal member 30 is provided on the outer periphery of the bead 23 on the protruding side, the space between the first and second substrates 10, 20 on the outer peripheral side of the beads 13, 23 is filled with the seal member 30. , The cooling water in the cooling water holes 17, 27 is the bead 1
It never reaches 3,23.

As described above, the beads 13 of the first substrate 10
Also, since the bead 23 of the second substrate 20 is limited in displacement by the shim ring 14 and the displacement amount is suppressed to be small, fatigue resistance is good, and the beads 13 and 23 are exposed to the cooling water by the seal member 30. There is no risk of deterioration due to rust. Moreover, the shim ring 14
Since the predetermined sealing function is ensured by itself, the shim ring 14, the beads 13, 23 and the sealing member 30 serve as a total of three sealing means for the combustion gas from the combustion chamber holes 11, 21. A stable sealing property is secured.

[0023]

Since the present invention is configured as described above, it has the following effects. That is, in the metal gasket of the present invention, the tops of the beads formed on one substrate and the tops of the beads on the other substrate are configured to face each other, and the beads on both substrates have the same thickness as the metal ring. The metal ring surely prevents the subsequent deformation, so that good fatigue resistance can be secured as compared with that of a single substrate. Further, since the seal member is appropriately provided on the outer periphery of the bead on the protruding side of the other substrate, it is possible to secure a stable sealing property over the entire circumference of the fluid hole together with the metal ring and the bead. Moreover, the seal member is configured to be disposed on a different substrate from the substrate to which the metal ring is bonded, and can be easily provided without being affected by the distortion of the substrate,
Manufacture is easy and good workability is obtained.

When the dimensional relationship between the two substrates, the bead, and the metal ring is set as described above, the bead displacement amount can be reduced without impairing the sealing function, and thus the bead fatigue resistance. Will increase further.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a metal gasket according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state where a metal gasket according to an embodiment of the present invention is sandwiched between a cylinder head and a cylinder block.

FIG. 3 is a plan view of a first substrate that constitutes a metal gasket according to an embodiment of the present invention.

FIG. 4 is a plan view of a second substrate that constitutes a metal gasket according to an embodiment of the present invention.

[Explanation of symbols]

 3 Cylinder Head 4 Cylinder Block 10 First Substrate 20 Second Substrate 11 and 21 Combustion Chamber Hole (Fluid Hole) 12,22 Bolt Hole 13,23 Bead 14 Shim Ring (Metal Ring) 16,26 Bead 17,27 Cooling Water Hole 18,28 Lubricant oil hole 19,29 Caulking hole 30 Seal member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shiro Kawai, 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor, Kazuya Nakata, 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation ( 72) Inventor Takeshi Kitamura 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (2)

[Claims] 1. At least two metal substrates, each having a fluid hole through which a pressure fluid passes and a bead formed around the fluid hole, are provided, and the two substrates are provided on top of each bead. In the metal gaskets arranged so as to face each other, of the two substrates, a metal ring is joined between the inner periphery of the bead protruding side of one substrate and the fluid hole, and the beat protruding side of the other substrate. A metal gasket characterized in that a seal member is arranged on the outer periphery of the metal gasket. 2. The thickness of the metal ring is smaller than the thickness of the one substrate, and the height of the bead of the one substrate is at least smaller than the thickness of the metal ring. The metal gasket according to claim 1.