JP3093398B2 - Metal gasket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. 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 joining members to prevent leakage of a pressure fluid from a joining surface. For example, a gasket is provided between a cylinder head and a cylinder block of an internal combustion engine. A cylinder head gasket is interposed. With regard to this type of gasket, a metal gasket made of a metal plate has recently been receiving attention.
For example, a fluid hole through which a pressure fluid such as a combustion gas passes is formed in a metal substrate, and a bead is formed around the fluid hole so that a high surface pressure can be secured to the joining member. Are known.

[0003] Regarding the above-mentioned metal gasket, as disclosed in, for example, Japanese Utility Model Laid-Open Publication No. Sho 59-188955, in order to prevent the bead from being plastically deformed by the tightening force and the sealing property from deteriorating, the height of the protrusion of the bead is reduced. It has been proposed to provide a surface pressure adjusting plate made of a thinner plate at a portion other than the bead. For the same purpose, various types in which a thick portion is formed on a substrate on the hole side with respect to a bead have been proposed. Regarding this thick portion, for example, Japanese Utility Model Laid-Open No. 61-14748 discloses a thick portion formed by plating, and Japanese Utility Model Application Laid-Open No. 2-6855 discloses a thick portion formed by bonding or welding a sub-plate. Japanese Patent Application Laid-Open No. 64-35057 discloses a stopper formed by thermal spraying (corresponding to a thick portion) which is impregnated with a filler such as resin to secure a sealing function. ing. In addition, Shokai 6
Japanese Patent Publication 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 a base portion on an outer peripheral side.

[0004]

The spacer such as the surface pressure adjusting plate and the thick portion is adjusted so that the beads can be compressed and deformed to function as a sealing member, and can function as a sealing member by itself. It is preferable that the metal ring be joined to the peripheral portion of the fluid hole of the substrate in consideration of assemblability, thickness control, cost, and the like.

However, if the metal ring is joined to the substrate by welding or the like instead of the thick portion in the cylinder head gasket described in Japanese Utility Model Application 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 the substrate. However, if the substrate is distorted, it is difficult to attach the sealing member to an appropriate position, and the productivity is reduced.

Incidentally, the above-mentioned Japanese Patent Application Laid-Open No. 64-35057.
In a metal gasket in which two identically shaped substrates having beads formed thereon are arranged so that their tops face each other, as shown in FIG. As a result, the displacement of the bead of each substrate can be reduced as compared with a single substrate, so that the fatigue resistance is improved.

In this publication, after a stopper is formed by thermal spraying, the stopper is impregnated with a resin, and the characteristics, manufacturing and assembling issues, etc. are different from those of joining a metal ring. Even if the stopper in the publication is replaced with a metal ring, the seal member will be formed on the outer periphery of the bead projecting side of the substrate to which the metal ring is joined, and the same problem as described above will occur when the seal member is provided. In addition, since the intermediate plate is interposed, the amount of material is increased, and the overall thickness 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, this does not mean that the intermediate plate may simply be removed.

Accordingly, the present invention provides a metal gasket having at least two metal substrates each having a bead formed around a fluid hole and arranged such that the top of each bead faces each other. It is an object of the present invention to dispose the members at appropriate positions so as to ensure stable sealing properties over the entire circumference of the fluid hole.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides at least two metal substrates each having a fluid hole through which a pressure fluid passes and a bead formed around the fluid hole. A metal gasket in which the two substrates are arranged such that the tops of the beads face each other, wherein, of the two substrates, the inner periphery of one of the substrates on the bead protruding side and the fluid hole A metal ring is joined therebetween, and a seal member is provided on the outer periphery of the other substrate on the bead projecting side.

[0010] In the metal gasket, the thickness of the metal ring may be smaller than the thickness of the one substrate, and the height of the bead of the one substrate may be smaller than the thickness of the metal ring.

[0011]

When the metal gasket having the above structure is interposed between the joining members facing each other, for example, between the cylinder head and the cylinder block, and the two are fastened with a predetermined tightening force, two substrates are formed. Are compressed and deformed, and a predetermined surface pressure on the joining member is secured by the elastic restoring force of the beads deformed and compressed. In this case, since the metal ring is joined between the inner circumference of the bead projecting side of one substrate and the fluid hole, the beads are deformed until the total height of both beads 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]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the metal gasket of the present invention will be described below with reference to the drawings. As the metal gasket to which the present invention is applied, a cylinder head gasket interposed between a cylinder head and a cylinder block of a multi-cylinder internal combustion engine is preferable. The gasket will be described.

FIG. 1 shows a cross section of an 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 shape shown in FIG. 10 and a second substrate 20 having a planar shape shown in FIG.
Are provided with a plurality of combustion chamber holes 11, 21, respectively. The first and second substrates 10 and 20 are provided with a plurality of cooling water holes 17 and 27 and lubricating oil holes 18 and 28, respectively, and a plurality of bolt holes around the combustion chamber holes 11 and 21. 12,
22 are drilled. For example, ten bolt holes 12 and 22 are formed around the combustion chamber holes 11 and 21 at substantially equal intervals, respectively. Further, the first and second substrates 10,
In order to join the holes 20, caulking holes 19, 2
9 are drilled.

The combustion chamber holes 11 and 21 are arranged in a straight line with a number corresponding to the number of cylinders (for example, four for an in-line four-cylinder internal combustion engine), and around the combustion chamber holes 11 and 21, respectively. Beads 13 and 23 are formed. Bead 13,2
The width of each of the combustion chamber holes 11 and 11 is equal to the width of each of the combustion chamber holes 11 and 21.
Beads 13 and 13 formed around (22, 22)
The width of the collecting portion of (3, 23) is set smaller than the width of each of the beads to be collected.

On a flat surface from the inner periphery of the first substrate 10 on the side of the bead 13 projecting side to the combustion chamber hole 11, a metal ring of a perfect circle having a predetermined width, for example, a spacer of a stainless steel plate, a so-called shim ring 14 is provided. Are joined. That is, the shim ring 14 is set to have a predetermined width sufficient to secure a sealing function by itself, and has a thickness Ts of FIG.
Is set 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 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
A continuous welded portion 15 (omitted in FIG. 3) is formed on the entire circumference.

In this embodiment, the height of the bead 23 is 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. The total height of 13 and 23 is shim ring 1
4 may have different heights if the thickness is larger than Ts. Further, the bolt holes 12, 22 and the lubricating oil holes 18, 2
Beads 16 and 26 are also formed around 8 and on the outer periphery of the first and second substrates 10 and 20. These beads 16 and 26 are constituted by steps or inclined portions and have a half shape of the beads 13 and 23, so that they are referred to as half beads.

A seal member 30 made of a vulcanized fluorine-based rubber is provided on the outer periphery of the second substrate 20 on the projecting side of the bead 23 so as to be continuous over the entire periphery of the bead 23. The seal 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 vulcanizing by heating at a predetermined temperature. Further, in order to ensure the sealing performance at the time of joining the cylinder head 3 and the cylinder block 4 described later, the sealing member 30 and the second
An unvulcanized or non-vulcanized rubber layer may be formed on the entire surface of the substrate 20. Here, the unvulcanized rubber refers to a rubber that does not contain a vulcanizing agent, and the unvulcanized rubber refers to a rubber that contains a vulcanizing agent but has not been vulcanized.
Accordingly, although the initial properties of the unvulcanized rubber have the same characteristics as the unvulcanized rubber, the vulcanization proceeds 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 such that the tops of the beads 13 and 23 face each other as shown in FIG. The metal gasket is formed by caulking through 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. In this embodiment, the second substrate 20 is arranged so as to be on the cylinder block 4 side, but the first substrate 10 may be arranged so as to be on the cylinder block 4 side.

When a clamping 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 thickness is larger than the thickness Ts of the shim ring 14, the beads 13 and 23 can be deformed until they are substantially equal to the thickness Ts of the shim ring 14, but are not further deformed.

That is, as shown in FIG.
Between the cylinder block 4 and the shim ring 14
Is compressed, the deformation of the beads 13 and 23 does not proceed any further, and the first substrate 10 and the second substrate 20 are respectively connected to the cylinder head 3 and the cylinder block 4 by the elastic restoring force. It will adhere. 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 and 20 on the outer periphery of the beads 13 and 23 is filled with the seal member 30. The cooling water in the cooling water holes 17 and 27 is
It does not reach 3,23.

As described above, the beads 13 of the first substrate 10
The displacement of the bead 23 of the second substrate 20 is limited by the shim ring 14 and the displacement is suppressed to a small value, so that the bead 23 has good fatigue resistance. Further, 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, shim ring 14
Since a predetermined sealing function is secured by itself, a total of three stages of sealing means of the shim ring 14, the beads 13, 23 and the sealing member 30 function for the combustion gas from the combustion chamber holes 11 and 21. , Stable sealing performance is ensured.

[0023]

Since the present invention is configured as described above, the following effects can be obtained. That is, in the metal gasket of the present invention, the top of the bead formed on one substrate and the top of the bead of the other substrate are configured to face each other, and the bead of both substrates is equal to the thickness of the metal ring. , But subsequent deformation is reliably prevented by the metal ring, so that better fatigue resistance can be secured as compared with a single substrate. In addition, since the sealing member is appropriately provided on the outer circumference of the other substrate on the bead projecting side, stable sealing properties can be secured 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 another substrate different from the substrate to which the metal ring is bonded, and can be easily provided without being affected by distortion or the like of the substrate.
It is easy to manufacture 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 displacement of the bead can be reduced without impairing the sealing function, so that the fatigue resistance of the bead can be reduced. Is further increased.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view showing a state in which a metal gasket according to one 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 constituting a metal gasket according to one embodiment of the present invention.

FIG. 4 is a plan view of a second substrate constituting the metal gasket according to one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 3 cylinder head 4 cylinder block 10 first substrate 20 second substrate 11, 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 Lubricating oil hole 19, 29 Caulking hole 30 Seal member

──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Shiro Kawai 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Kazuya Nakata 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation ( 72) Inventor Takeshi Kitamura 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (56) References JP-A-64-73157 (JP, A) JP-A-59-1888955 (JP, U) 63-74561 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16J 15/00-15/14

Claims (2)

(57) [Claims] At least two metal substrates each having a fluid hole through which a pressurized fluid passes and a bead formed around the fluid hole are provided, and the two substrates have a top portion of each bead. In a metal gasket arranged to face each other, a metal ring is joined between an inner periphery of a bead projecting side of one of the two substrates and the fluid hole, and a beat projecting side of the other substrate is provided. A metal gasket, wherein a seal member is provided on the outer periphery of the metal gasket. 2. The method according to claim 1, wherein 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 smaller than the thickness of the metal ring. The metal gasket according to claim 1.