JPH11108191A - Metallic gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic gasket provided with projections and having a durability of stopper performance against a bead. SOLUTION: The metallic gasket 50 is constituted of two base plates 1, 2 and an intermediate plate 3, and has serially arranged four combustion chamber holes and a plurality of cylinder-head bolt holes. In the base plates 1, 2, beads 6, 7 are projected toward the intermediate plate 3 side so as to surround the combustion chamber holes. The intermediate plate 3 has projections 8, 9 which project toward the base plate 1, 2 sides, respectively, and which are arranged around the combustion chamber holes and opposite to a plane part inside each of the beads 6, 7 of the base plates 1, 2. Two projections 8 are provided concentrically on the base plate 1 side, and three projections 9 are provided concentrically on the base plate 2 side. A section of each of the projections 8, 9 is solid rectangle, the projections are perpendicularly projected, and projecting end face acts as a stopper on the beads 6, 7 of the base plate 1, 2, respectively. Soft material 10 can be filled inside a cavity opposite to the projections 8, 9 of the intermediate plate 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal gasket interposed at a joint between a cylinder head and a cylinder block. More specifically, an intermediate plate is provided between two substrates made of an elastic metal plate formed with beads. The present invention relates to a laminated metal gasket.

[0002]

2. Description of the Related Art A bead is formed on a metal gasket used at a joint between a cylinder head and a cylinder block to seal a deck surface. In addition, a combination of an intermediate plate provided with a step and an intermediate plate obtained by turning a shim plate around a combustion chamber hole serves as a stopper against crushing of a bead (see JP-A-5-52268). In addition, this portion generates a high surface pressure when tightening, and functions as a primary seal of the combustion gas.

Further, the metal gasket described in Japanese Patent Application Laid-Open No. Hei 8-100859 has a bead crush prevention and a primary sealing function of combustion gas only by a step-formed intermediate plate.

[0004]

Problems to be Solved by the Invention Japanese Patent Laid-Open No. 5-52268
When a shim plate is used as a stopper, the metal gasket No. has a limitation in setting the plate thickness, and it is difficult to finely adjust the thickness. Therefore, it is difficult to finely adjust the surface pressure. In addition, there is a limit to the thickness of the sheet that can be used in terms of processing such as folding and welding and handling. In addition, since the stopper amount varies depending on the engine, shim plates having various thicknesses must be prepared.

Further, in the metal gasket disclosed in Japanese Patent Application Laid-Open No. Hei 8-100859, since the second step of one intermediate plate is larger than the first step, a substantial amount of stopper is required when the intermediate plate is bent and deformed. There is a disadvantage that it decreases. Furthermore,
Since only one step is formed above and below, it is difficult to appropriately change the amount of stopper in the circumferential direction of the combustion chamber hole.

It is an object of the present invention to provide a metal gasket having an intermediate plate having a protrusion having excellent durability of a stopper function for a bead.

[0007]

According to the present invention, an intermediate plate is laminated between two substrates made of an elastic metal plate formed with a bead. And a protrusion protruding toward the two substrates at a position facing the flat portion inside the bead. The cross section of the protrusion is, for example, a solid rectangular shape.

Since the raised surface has a vertical rising surface, it is hardly deformed and has excellent durability of a stopper function for beads. In addition, the amount of step can be freely set by press molding, and the surface pressure can be finely adjusted. By forming multiple protrusions between the combustion chamber hole and the bead,
The stopper effect on the beads is improved.

In order to reduce the level difference of the protrusion, the following configuration can be adopted. That is, two intermediate plates are laminated between two substrates made of an elastic metal plate formed with a bead, and one of the intermediate plates is a flat portion around the combustion chamber hole and inside the bead of the substrate. A step-like step portion protruding toward one of the substrates at a position facing the first intermediate plate, and the other intermediate plate has, at an edge around a combustion chamber hole, a folded piece folded toward the one intermediate plate. In the metal gasket described above, the one intermediate plate further has a protrusion protruding toward the substrate at a protruding portion of the step-shaped step portion.

[0010] Thereby, the forming margin of the protrusion is small, and the forming process is facilitated.

The same effect as described above can also be obtained by the following configuration. That is, an intermediate plate is laminated between two substrates made of an elastic metal plate formed with a bead, and the intermediate plate is located around a combustion chamber hole and faces a flat portion inside the bead of the substrate. A metal gasket having a step-like stepped portion protruding toward one substrate side, and a shim plate fixed to the intermediate plate side surface of a flat portion inside a bead of the other substrate. Is in the protruding portion of the step-shaped step portion,
Further, it is characterized by having a protrusion protruding toward the substrate side.

The above-mentioned protrusion of the intermediate plate is formed partially or entirely around the combustion chamber hole. In addition, the protrusion may be constituted by a portion having a constant step and a portion having a step change around the combustion chamber hole.

Therefore, the metal gasket of the present invention is protruded from the intermediate plate at a location where the gap between the deck surface of the cylinder head and the cylinder block is larger than the vicinity of the head bolt, ie, at a location apart from the head bolt hole. Is formed, and in the vicinity of the head bolt hole, by forming no protrusion on the intermediate plate, it is possible to ensure uniform surface pressure by coping with a change in the tightening gap between the cylinder head and the cylinder block. .

Further, the protrusion of the intermediate plate is provided around the entire circumference of the combustion chamber hole, and the height of the step is reduced near the head bolt hole and increased at a position distant from the head bolt hole. A uniform surface pressure can be ensured by coping with the change in the tightening gap with the cylinder block.

As described above, by making the protrusion corresponding to the change in the tightening gap of the deck surface between the cylinder head and the cylinder block correspond to the surface pressure, a uniform surface pressure can be secured, and the sealing property of the combustion gas can be secured. . Since the protrusion has a step amount corresponding to the change, the forming allowance is small and the forming process is easy.

If the soft material is filled in the concave portion of the intermediate plate opposite to the protrusion, it is possible to prevent the protrusion from being crushed due to the repeated load due to the tightening and operation of the head bolt.

[0017]

1 to 3 show an embodiment of the present invention.
This will be described below. FIG. 3 does not show the protrusions shown in FIG.

The metal gasket 50 includes two substrates 1
2 and one intermediate plate 3 laminated between them, four combustion chamber holes 4 arranged in series, and a plurality of head bolt holes 5 through which head bolts are inserted.
Are formed so as to penetrate the plates 1, 2, 3.

The plurality of head bolt holes 5 are provided at predetermined intervals on the peripheral edge of the metal gasket 50, and are provided at both sides of the crankshaft between the respective combustion chamber holes 4.

Each of the substrates 1 and 2 is made of an elastic metal plate, and the beads 6 and 7 are formed so as to protrude toward the intermediate plate 3 so as to surround the combustion chamber hole 4.

The intermediate plate 3 has substantially the same shape as the substrates 1 and 2, and is located around the combustion chamber hole 4 and at a position facing the flat portions inside the beads 6 and 7 of the substrates 1 and 2. The projections 8 and 9 project from the two substrates 1 and 2 respectively.
Each of the protrusions 8 and 9 is formed so as to protrude annularly along the entire periphery of the combustion chamber hole 4. Protruding projection 9
Are formed concentrically. The cross section of each protrusion 8, 9 is a solid rectangular shape, the rising surface is vertical, the protruding end surface protrudes by a predetermined amount from the surface of the intermediate plate 3, and the beads 6, 7 It functions as a stopper for.

The metal gasket 50 is interposed between the cylinder head and the cylinder block, and is fastened with a head bolt.

The operation will be described below.

The metal gasket 50 interposed between the cylinder head and the cylinder block is compressed by the tightening force of the head bolt, and the beads 6, 7 of each of the substrates 1, 2 are pressed against the intermediate plate 3 to bead. 6, 7 are compressed and deformed.

At this time, the elastic deformation of the beads 6 and 7 is suppressed by bringing the substrates 1 and 2 into contact with the protrusions 8 and 9 of the intermediate plate 3.

In this case, since the protrusions 8 and 9 have vertical rising surfaces, they are not easily deformed, and the durability of the stopper function for the beads 6 and 7 is excellent. Also, protrusions 8, 9
Are formed between the combustion chamber hole 4 and the beads 6 and 7, respectively, so that the stopper function for the beads 6 and 7 is excellent. In addition, the amount of step can be freely set by press molding, and the surface pressure can be finely adjusted.

As shown in FIG. 1B, the intermediate plate 3
If the soft material 10 is filled in the concave portion on the opposite side of each of the protrusions 8 and 9, the protrusions 8 and 9 can be prevented from being crushed. As the soft material 10, a heat-resistant rubber (for example, fluoro rubber) can be used.

4 to 6 show another embodiment 2 of the present invention. Note that FIG. 6 does not show the step-shaped steps and protrusions shown in FIG.

The second embodiment is different from the first embodiment in the structure of the intermediate plate.

The metal gasket 50A includes two substrates 1 and 2 and two intermediate plates 3 stacked therebetween.
A, 3B, and 4 arranged in series.
One combustion chamber hole 4 and a plurality of head bolt holes 5 through which head bolts are inserted are formed through the respective plates 1, 2, 3A, 3B.

One intermediate plate 3A has substantially the same shape as the substrates 1 and 2, and is located at a position around the combustion chamber hole 4 and facing a flat portion inside the bead 6 of the one substrate 1. It has a step-shaped step portion 11 protruding toward one substrate 1 side. The step-shaped step portion 11 is formed to protrude annularly along the entire periphery of the combustion chamber hole 4.

A protruding portion 12 protruding toward one of the substrates 1 is formed at a protruding portion of the step-like stepped portion 11 at a position distant from each head bolt hole 5 along the periphery of the combustion chamber hole 4, that is, a crankshaft. Are formed so as to protrude in an arc shape at a portion above (a portion A and a portion C in FIG. 6). Two protrusions 12 are formed concentrically. Protrusion 12
Has a solid rectangular shape, the rising surface is vertical, and the protruding end surface protrudes by a predetermined amount from the surface of the intermediate plate 3A, and functions as a stopper for the bead 6 of the substrate 1.

The other intermediate plate 3B has substantially the same shape as the substrates 1 and 2, and has a folded piece 13 which is folded toward one intermediate plate 3A on the entire peripheral edge of the combustion chamber hole 4. ing. This folded piece 13 is arranged at the step-like stepped portion 11 of one intermediate plate 3A, and the adjacent substrate 2
Functions as a stopper for the bead 7.

The operation will be described below.

The metal gasket 50A interposed between the cylinder head and the cylinder block is compressed by the tightening force of the head bolt, and the beads 6, 7 of the substrates 1, 2 are pressed against the intermediate plates 3A, 3B. Then, the beads 6 and 7 are compressed and deformed.

At this time, the elastic deformation of each of the beads 6 and 7 is suppressed by contacting the substrate 1 with the step-shaped step portion 11 and the projection 12 of the intermediate plate 3A and the substrate 2 with the folded piece 13 of the intermediate plate 3B. Is done.

That is, the cylinder head is deformed by the tightening force of the head bolt, and the clearance between the cylinder head and the cylinder block on the deck surface is small near the head bolt and large at a point far from the head bolt.

However, in the metal gasket 50A of the second embodiment, as described above, the projections 12 are further formed at the steps A and C at the portions A and C far from the head bolt hole 5. Since the gap between the cylinder head and the cylinder block is changed, the surface pressure around the combustion chamber hole 4 becomes uniform, and a reliable seal is ensured.

FIG. 7 shows still another embodiment 3 of the present invention. In the third embodiment, a shim plate is fixed to the substrate side instead of the intermediate plate having the folded pieces of the second embodiment.

The metal gasket 50B is composed of two substrates 1 and 2 and one intermediate plate 3 laminated between them.
A, a shim plate 14 welded to the surface of the substrate 2 on the intermediate plate 3A side, four combustion chamber holes 4 arranged in series, and a plurality of head bolt holes through which head bolts are inserted. 5 are formed through the respective plates 1, 2, 3A.

The shim plate 14 is laser-welded to the surface of the flat plate inside the bead 7 of the substrate 2 on the side of the intermediate plate 3A. FIG.
In the above, W indicates a welding position. The shim plate 14 has the combustion chamber hole 4
Is arranged annularly at a position corresponding to the step-shaped step portion 11 of the intermediate plate 3A around the entire periphery of the intermediate plate 3A, has a thickness larger than the step amount of the step-shaped step portion 11, and Function as a stopper.

In the third embodiment, the second embodiment is also used.
In the same manner as described above, a step 12
Is formed to cope with the change in the gap between the cylinder head and the cylinder block, so that the surface pressure around the combustion chamber hole 4 becomes uniform and a reliable seal is assured.

In the second and third embodiments, as described in the first embodiment, the protrusion 12 of the intermediate plate 3A is used.
The soft material can be filled in the concave portion on the side opposite to the above.

In the first embodiment, the protrusions are formed around the entire circumference of the combustion chamber hole (however, the level difference is constant). In the second and third embodiments, the protrusions are partially formed. However, the present invention is not limited to this, and it is also possible to form a protrusion around the entire circumference of the combustion chamber hole 4 and change the level difference in accordance with the change in the gap between the cylinder head and the cylinder block. For example, the step is small at a position near the head bolt hole 5, ie, the portion B in FIG. 6, and the step is large at a position away from the head bolt hole 5, ie, a portion A in FIG. In this case, the step may be gradually changed to smoothly connect the portion A and the portion B.

[0045]

As described above, in the metal gasket of the present invention, the intermediate plate has a protrusion having excellent durability of the stopper function for the bead, thereby ensuring a reliable seal.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a metal gasket of the present invention, in which (a) is a cross-sectional view taken along the line aa of FIG. 2, and (b) is an example in which a soft material is filled in the cross-sectional view.

FIG. 2 is a plan view showing one embodiment of a metal gasket of the present invention.

FIG. 3 is a plan view showing an intermediate plate.

4A and 4B show another embodiment of the metal gasket of the present invention, wherein FIG. 4A is a sectional view taken along line aa of FIG. 5, and FIG.
It is a -b line sectional view.

FIG. 5 is a plan view showing another embodiment of the metal gasket of the present invention.

FIG. 6 is a plan view showing an intermediate plate.

7 shows yet another embodiment of the metal gasket of the present invention, wherein (a) and (b) are cross-sectional views corresponding to FIG.

[Explanation of symbols]

 Reference numerals 1, 2 Substrate 3, 3A, 3B Intermediate plate 4 Combustion chamber hole 5 Head bolt hole 6, 7 Bead 8, 9 Projection 10 Soft material 11 Step-like stepped portion 12 Projection 13 Folded piece 14 Shim plate W Welding point 50, 50A, 50B Metal gasket

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akira Sugawara 3308, Oji-sanjiri Exit, Kumagaya-shi, Saitama Japan Metal Gasket Co., Ltd.

Claims (10)

[Claims] 1. An elastic metal plate formed by forming a bead.
Intermediate plates are stacked between the two substrates, and the intermediate plates project toward the two substrates at positions around the combustion chamber holes and opposed to flat portions inside the beads of the substrates. A metal gasket, characterized in that it has an opening. 2. An elastic metal plate formed with a bead.
Two intermediate plates are stacked between the two substrates, and one intermediate plate protrudes toward the one substrate at a position around the combustion chamber hole and opposed to a flat portion inside the bead of the substrate. A metal gasket having a step-like stepped portion, wherein the other intermediate plate has a folded piece folded back toward the one intermediate plate at an edge around a combustion chamber hole; The metal gasket, wherein the plate further has a protrusion protruding toward the substrate at a protruding portion of the step-shaped step portion. 3. An elastic metal plate formed with a bead.
An intermediate plate is laminated between the two substrates, and the intermediate plate projects toward one of the substrates at a position around the combustion chamber hole and opposed to a flat portion inside the bead of the substrate. In a metal gasket having a shim plate adhered to the surface of the intermediate substrate side of the flat portion inside the bead of the other substrate, the intermediate plate has a protruding portion in the step-shaped step portion, Furthermore, a metal gasket having a protrusion protruding toward the substrate side. 4. The metal gasket according to claim 1, wherein the cross section of the protrusion of the intermediate plate has a solid rectangular shape. 5. A plurality of protrusions of the intermediate plate are formed between a combustion chamber hole and a bead.
5. The metal gasket according to any one of 4. 6. The metal gasket according to claim 1, wherein the protrusion of the intermediate plate is formed at a part around the combustion chamber hole. 7. The metal gasket according to claim 1, wherein the protrusion of the intermediate plate is formed all around the combustion chamber hole. 8. The method according to claim 1, wherein the protrusion of the intermediate plate includes a portion having a constant step and a portion having a step change around the combustion chamber hole. A metal gasket described in Crab. 9. The metal gasket according to claim 1, wherein the protrusion of the intermediate plate is formed by press forming. 10. A soft material is filled in a concave portion of the intermediate plate opposite to the protrusion.
10. The metal gasket according to any one of items 9 to 9.