JP3310329B2 - Cylinder head 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 cylinder head gasket interposed between a cylinder head and a cylinder block of an internal combustion engine, and more particularly, to forming a combustion chamber hole in a metal substrate and forming a bead around the hole. In addition, the present invention relates to a cylinder head gasket in which a seal member is provided along the outer periphery of a bead.

[0002]

2. Description of the Related Art With regard to a cylinder head gasket interposed between a cylinder head and a cylinder block of an internal combustion engine, a cylinder head gasket made of a metal plate has recently attracted attention. For example, a plurality of combustion chamber holes through which a combustion gas passes are formed in a metal substrate, and beads are formed around each combustion chamber hole so that a high surface pressure can be secured to the joining member. It has been known.

[0003] With regard to such a cylinder head gasket, for example, Japanese Utility Model Laid-Open Publication No. 64-8556 discloses a method in which a soft sealing member is provided at the base of a bead on the water hole side to prevent corrosion due to water penetration. A disclosed cylinder head gasket is disclosed. In addition, the actual opening Hei 1-141354
Japanese Patent Application Laid-Open Publication No. H11-139,086 also discloses a metal gasket for a cylinder head in which a heat-resistant elastic member layer is formed all around or partly along the periphery of a bead. Furthermore, it is actual fair 2-35086
In the publication, the top of the bead portion of the metal gasket substrate,
Change the thickness and width of the sealing material applied according to the magnitude of the contact surface pressure of the mating surface acting on the base, and maintain the desired sealing pressure of the bead part by applying the sealing material by screen printing. It has been proposed to save expensive sealing material.

[0004]

Problems to be Solved by the Invention
In the cylinder head gasket described in JP-B-56, although a seal member is provided at the base of the bead, that is, at the hem edge, the sealing performance against combustion gas is improved, but a substantially uniform surface pressure along the bead is obtained. It is desired to secure. In particular, the cylinder head gasket has a plurality of bolt holes formed around the combustion chamber hole, and is tightened between the cylinder head and the cylinder block by bolts inserted through the holes. In this case, a large axial force is applied as compared with other portions, and the surface pressure is increased.
In other words, the gap between the cylinder head and the cylinder block is smaller on the outer circumferential side than on the inner circumferential side of the bead, but this difference is larger in the portion near the bolt hole than in the portion located between the mutually adjacent bolt holes. Therefore, the cylinder head gasket needs to have a surface pressure distribution according to the distribution of the fastening force between the cylinder head and the cylinder block of the internal combustion engine to which the cylinder head gasket is mounted.

In Japanese Utility Model Publication No. 2-35086 mentioned above,
Although it is described that the desired sealing pressure of the bead portion is maintained by changing the thickness of the sealing material attached to the bead portion, the distribution of the surface pressure on the seal member itself provided on the outer periphery of the bead is attempted. In addition, it does not correspond to the distribution of the fastening force to the cylinder head gasket as described above.

In view of this, the present invention provides a metal substrate having a combustion chamber hole through which a combustion gas passes, forming a bead around the combustion chamber hole, and arranging a seal member along the outer periphery of the bead projecting side. In a cylinder head gasket to be provided, it is an object to secure a substantially uniform surface pressure of a seal member along the outer periphery of a bead.

[0007]

Means for Solving the Problems] To achieve the above object, the present invention includes a plurality of combustion gas passes a metallic substrate
While bored in the combustion chamber holes in a row, of the plurality of combustion chamber holes around the positions of the left and right sides in the longitudinal direction on both sides of the substrate
The plurality of combustion chamber holes face intermediate portions adjacent to each other.
In a cylinder head gasket, a plurality of bolt holes are drilled at positions , a bead is formed to protrude around the combustion chamber hole, and a seal member is provided along an outer periphery on a protruding side of the bead. A portion of the seal member is disposed at a position at least partially on the bead and close to the top of the bead, and a portion of the seal member located between the bolt holes adjacent to each other and separated from the bolt hole . The sealing member is disposed at a position separated from the top of the bead.

In the cylinder head gasket,
Or positioned between the bolt holes adjacent to each other the bolt holes
The thickness of the seal member at a portion separated from the bolt hole may be set to be larger than the thickness of the seal member near the bolt hole.

[0009]

When the cylinder head gasket having the above structure is interposed between the cylinder head and the cylinder block and the two are fastened with a predetermined tightening force, the bead is compressed and deformed. A predetermined surface pressure against the cylinder head and the cylinder block is ensured by the elastic restoring force of the deformed bead, and the seal member is in close contact with one of them, thereby sealing between them. In this case, at least a part of the seal member in the vicinity of the bolt hole is disposed at a position close to the top of the bead on the bead, and is located between adjacent bolt holes and separated from the bolt hole.
Since the seal member at the separated portion is disposed at a position separated from the top of the bead, substantially uniform surface pressure is obtained along the outer periphery of the bead.

Furthermore, located between the bolt holes adjacent to each other
If the thickness of the seal member at a portion separated from the bolt hole is set to be larger than the thickness of the seal member near the bolt hole, it is easy even when the fastening force applied to the cylinder head gasket concentrates on the fastening portion. , And a substantially uniform surface pressure can be obtained.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show a cylinder head gasket 1 interposed between a cylinder head 3 and a cylinder block 4 of a multi-cylinder internal combustion engine according to an embodiment of the present invention. A substrate 10 made of a steel plate (SUS) is provided. The substrate 10 has a number corresponding to the number of cylinders, for example, four combustion chamber holes 11 for an in-line four-cylinder internal combustion engine.
Are drilled on a straight line. Further, a plurality of cooling water holes 17 and lubricating oil holes 18 are formed in the substrate 10 so that the combustion chamber holes 1 are formed.
A plurality of bolt holes 12 are formed around one.

Further, a bead 1 is provided around each combustion chamber hole 11.
3 are formed. This bead 13 is used for each combustion chamber hole 11.
Are formed to have the same width over the entire circumference, but merge into a single bead at a portion located between the adjacent combustion chamber holes 11 and 11. Bolt holes 12 are provided for each combustion chamber hole 11
For example, ten bolts (not shown) are formed at substantially equal intervals around each of them, and fastening bolts (not shown) are inserted into each of them, and tightened between the cylinder head 3 and the cylinder block 4 as shown in FIGS. 7 and 8. .

A completely circular metal ring having a predetermined width, for example, a spacer made of a stainless steel plate, that is, a so-called shim ring 14, is joined to the flat surface of the substrate 10 from the outer peripheral edge of the projecting side of the bead 13 to the combustion chamber hole 11. ing. The shim ring 14 is set to have a predetermined width sufficient to secure a sealing function by itself, and is set to be thinner than the height of the bead 13.
For example, it is substantially continuously welded to the substrate 10 over the entire circumference by a pulse-driven laser welding machine. As a result, a welded portion 15 is formed on the entire circumference of the shim ring 14 as shown in FIG.

A seal member 16 made of, for example, a vulcanized fluorine-based rubber is provided along the outer periphery of the bead 13 on the protruding side. That is, as shown in FIG. 1, the seal member 16 has a portion near the bolt hole 12 (a portion within a range of the central angle a with respect to the combustion chamber hole 11) on the bead 13 as shown in FIG. Is attached to a position close to the top of the bead 13 (a position Sa from the top of the bead 13 in FIG. 1) indicated by a dashed-dotted circle. As shown in FIG. 3, the seal member 16 at the portion located between the adjacent bolt holes 12, 12 (the portion within the range of the central angle c in FIG. 4) (Position at a distance Sc from the top of the bead 13).
3 is disposed at a position away from the top.

As shown in FIG. 2, the sealing member 16 at the longitudinal end portion of the substrate 10 (the portion located within the range of the central angle b in FIG. 4) has an inner peripheral end located at an intermediate position between the two positions as shown in FIG. (Position of distance Sb from the top of the bead 13). Further, the seal member 16 at the portion where the combustion chamber holes 11 and 11 face the intermediate portion adjacent to each other, that is, the portion shown as the range of the central angle c ′ in FIG. 4 is located between the adjacent bolt holes 12 and 12. Similarly to the part shown in FIG.

In the above embodiment, the thickness of the sealing member 16 is set to be equal to or slightly smaller than the thickness of the shim ring 14, but the thickness of the sealing member 16 is set in the circumferential direction. May be set differently. That is, the thickness of the seal member 16 in the portion located between the adjacent bolt holes 12, 12 (the portion in the range of the central angle c in FIG. 4) is reduced to the vicinity of the bolt hole 12 (the range in the central angle a in FIG. 4). Part)
The thickness is set to be larger than the thickness of the seal member 16.
In this case, the locus can be set so that the difference between the proximity amount of the portion near the bolt hole 12 of the seal member 16 and the separation amount of the portion located between the adjacent bolt holes 12 can be set small. Further, when a certain amount of material is supplied along the outer periphery of the bead 13 to form the seal member 16, as shown in FIG. 6, the width of the seal member 16 at the portion located between the adjacent bolt holes 12, 12 is reduced. And the width of the seal member 16 in the vicinity of the bolt hole 12 becomes smaller. Of course, the supply amount of the material of the seal member 16 may be adjusted so that the seal member 16 has the same width over the entire circumference. In the example of FIG. 6, the thickness of the seal member 16 at a portion located between the adjacent bolt holes 12, 12 is set to be larger than the thickness of the seal member 16 near the bolt hole 12. Further, the thickness in the range indicated by the central angle d in FIG. 6 may be set to an intermediate value between the thicknesses of the two portions to form a smooth surface. In FIGS. 4 and 6, it is preferable that the connecting portion (the portion between the center angle a and the center angle c) of the portions having different trajectories and widths of the seal member 16 is gradually changed.

Although not shown, the substrate 10 and the shim ring 14 are attached before the seal member 16 of this embodiment is attached.
It is desirable to form a vulcanized rubber layer made of vulcanized fluoro rubber on the entire surface of the substrate. Further, in order to ensure the sealing performance when joining with the cylinder head 3 and the cylinder block 4, non-vulcanized rubber containing no vulcanizing agent or vulcanizing agent is applied to the entire surface of the sealing member 16, the shim ring 14, and the substrate 10. An unvulcanized rubber that contains a vulcanizing agent but has not been vulcanized may be attached. In the case where the difference between the proximity amount and the separation amount is set to be large in FIG.
It is good to use a rubber material which adheres strongly to the side. When the portion located between the adjacent bolt holes 12 and 12 is raised, there is little fear of displacement, and particularly when the seal member 16 is set as shown in FIG. A rubber material having the same can also be used.

The cylinder head gasket 1 constructed as described above is interposed between the cylinder head 3 and the cylinder block 4 as shown in FIGS. 7 and 8, and when a tightening force is applied, the beads 13 are compressed and deformed. I do. At this time, since the height of the bead 13 is greater than the thickness of the shim ring 14, the bead 13 can be deformed until it becomes equal to the thickness of the shim ring 14, but no more. That is, when the gap between the cylinder head 3 and the cylinder block 4 is tightened and the shim ring 14 is compressed, the deformation of the bead 13 does not proceed any further, and the cylinder head gasket 1 is moved by the elastic restoring force. 3 and the cylinder block 4.

In addition, the cylinder head gasket 1
Since the seal member 16 is provided according to the distribution of the fastening force applied to the cylinder head, a substantially uniform surface pressure distribution is obtained along the outer periphery of the bead 13 with respect to the seal member 16 of the cylinder head gasket 1, Stable sealing performance is ensured.

That is, since the tightening force is large in the vicinity of the bolt hole 12, as shown in FIG. 7, the bolts are separated from the outer peripheral skirt of the bead 13 as shown in FIG. 7) (from left to right in FIG. 7), the gap between the cylinder head 3 and the cylinder block 4 becomes smaller. In contrast, adjacent bolt holes 12,
At a position separated from the bolt, such as between 12, the gap between the cylinder head 3 and the cylinder block 4 at the outer peripheral edge of the bead 13 is larger than that in FIG. 7, as shown in FIG. Thus, the sealing member 1 near the bolt hole 12
The seal member 6 is disposed at a position close to the top of the bead 13 where a large gap can be maintained as shown in FIG. 7, so that a portion of the seal member located between the adjacent bolt holes 12, 12 shown in FIG. A surface pressure substantially equal to 16 is obtained.

Further, when the fastening force is concentrated in the vicinity of the bolt hole 12, the thickness of the seal member 16 in the portion located between the adjacent bolt holes 12, 12 as shown in the embodiment of FIG. If the thickness is set to be larger than the thickness of the seal member 16 in the vicinity of the bolt hole 12, even if the gap between the cylinder head 3 and the cylinder block 4 becomes large, it is possible to easily follow the gap. In addition, it is possible to almost eliminate the risk of the seal member 16 being displaced toward the bead 13 or the like.

In the above embodiment, the cylinder head gasket 1 is constituted by one substrate 10, but the other substrate (not shown) having a symmetrical shape is brought into contact with the top of each bead. And the two substrates may be joined together. In this case, for example, it is preferable that the shim ring 14 is fixed to one substrate and the seal member 16 is provided on the other substrate.

[0023]

Since the present invention is configured as described above, the following effects can be obtained. That is, in the cylinder head gasket of the present invention, at least a part of the sealing member in the vicinity of the bolt hole is disposed at a position close to the top of the bead and on the bead, and between the bolt holes adjacent to each other. Since the seal member located at a position separated from the bolt hole is disposed at a position separated from the top of the bead, substantially uniform surface pressure is obtained along the outer periphery of the bead with respect to the seal member, and stable sealing performance is obtained. Can be secured.

Furthermore, located between the bolt holes adjacent to each other
According to the cylinder head gasket in which the thickness of the seal member at a portion separated from the bolt hole is set to be larger than the thickness of the seal member near the bolt hole, the fastening force applied to the cylinder head gasket concentrates on the fastening portion. In such a case, it is possible to easily follow, and a stable sealing property can be ensured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a bead periphery near a bolt hole of a cylinder head gasket according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a bead peripheral portion on a longitudinal end side of a cylinder head gasket according to one embodiment of the present invention.

FIG. 3 is a sectional view of a bead peripheral portion located between adjacent bolt holes of a cylinder head gasket according to one embodiment of the present invention.

FIG. 4 is a plan view of a portion bisected in a longitudinal direction of a cylinder head gasket according to one embodiment of the present invention.

FIG. 5 is an enlarged plan view showing a seal member disposing portion of the cylinder head gasket according to one embodiment of the present invention.

FIG. 6 is an enlarged plan view showing a seal member disposing portion of a cylinder head gasket according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view of a portion near a bolt hole in a state where a cylinder head gasket according to one embodiment of the present invention is interposed and fastened between a cylinder head and a cylinder block.

FIG. 8 is a cross-sectional view of a portion located between bolt holes in a state where the cylinder head gasket according to one embodiment of the present invention is interposed and fastened between the cylinder head and the cylinder block.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 11 Combustion chamber hole 12 Bolt hole 13 Bead 14 Shim ring 16 Seal member

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Zenichi Shinbo 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 (56) References JP-A-4-69461 (JP, A) JP-A-3-156154 (JP, A) JP-A-4-296257 (JP, A) JP-A-5-126257 (JP, A) Opened 61-114057 (JP, U) Opened 61-114056 (JP, U) Opened 62-177963 (JP, U) Opened 64-6456 (JP, U) (58) Int.Cl. ⁷ , DB name) F16J 15/12

Claims (2)

(57) [Claims] 1. A plurality of substrates through which a combustion gas passes through a metal substrate.
While bored in the combustion chamber holes in a row, of the plurality of combustion chamber holes around the positions of the left and right sides in the longitudinal direction on both sides of the substrate
The plurality of combustion chamber holes face intermediate portions adjacent to each other.
In a cylinder head gasket, a plurality of bolt holes are drilled at positions , a bead is formed to protrude around the combustion chamber hole, and a seal member is provided along an outer periphery on a protruding side of the bead. A portion of the seal member is disposed at a position at least partially on the bead and close to the top of the bead, and a portion of the seal member located between the bolt holes adjacent to each other and separated from the bolt hole . A cylinder head gasket, wherein the seal member is disposed at a position separated from a top of the bead. 2. A located between the bolt holes adjacent to each other
The cylinder head gasket according to claim 1, wherein a thickness of the seal member at a portion separated from the bolt hole is set to be larger than a thickness of the seal member at a portion near the bolt hole.