JPH018678Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention relates to the improvement of metal gaskets, and in particular, to make the distance between the fastening bolt hole and the bead approximately the same by bringing the meeting part of the bead closer to the fastening part. The present invention relates to a metal gasket that forcibly flattens the meeting portion of the beads by the pressing force during fastening, thereby improving sealing performance.

[Technical background of the invention]

A metal gasket is made by forming a bead on an elastic metal plate and using this bead to seal the joint surface of, for example, a cylinder head and a cylinder block.The metal gasket forms a seal line on the joint surface, which is a deck surface, by the tightening force of a bolt. This gives a sealing effect.

[Problems with background technology]

However, as shown in FIGS. 3 and 4, such a metal gasket 2 is
The first and second swollen portions 12a and 14a of the first and second beads 12 and 14, respectively, are surrounding beads.
A third bead 16, which is a connecting bead, is formed between meeting portions 18, 18 where the first and second bulging portions 12a, 14a meet. Since these meeting parts 18, 18 have beads meeting together in a complicated manner, a seal line is hardly generated, and moreover, they are close to the first and second cylinder holes 6, 8. For this reason,
When the engine is operating, the seal line is easily cut at the meeting point due to the pressure difference between adjacent cylinder holes, resulting in a problem of leakage.

[Purpose of invention]

Therefore, the purpose of this invention is to bring the meeting part of the bead formed on the metal gasket closer to the fastening part so that the distance between the fastening bolt hole and the bead is approximately the same, and to use surface pressure during fastening to close the meeting part. The bead is flattened to improve sealing performance at the meeting area,
The object of the present invention is to realize a metal gasket that can reliably prevent leakage.

[Structure of the idea]

In order to achieve this object, this invention provides a metal gasket in which a seal is achieved by forming beads on an elastic metal plate, in which beads are provided to surround and seal a plurality of cylinder holes provided in the elastic metal plate, and Fastening bolt holes are drilled at desired locations on the plate, and the connecting portions of the beads are formed close to the fastening bolt holes so that the distances between the fastening bolt holes and the beads are approximately the same. Features.

[Embodiments of the invention] Examples of the invention will be described in detail below based on the drawings.

Figures 1 and 2 show an embodiment of this invention. In FIG. 1, 2 is a metal gasket for an internal combustion engine, 4 is a substrate made of an elastic metal plate, 6 is a first cylinder hole, 8 is a second cylinder hole, and 10 is a bolt hole which is a fastening part. Beads are formed on the substrate 4 to seal each sealing portion, and the structure is configured to absorb any strain between the cylinder head and the cylinder block. A first bead 12 is provided in this bead so as to surround the first cylinder hole 6 formed in the substrate 4 of the metal gasket 2. Further, a second bead 14 is provided to surround the second cylinder hole 8.
Further, between the meeting parts 18, 18 formed by the meeting of the first and second bulging parts 12a, 14a of the first bead 12 and the second bead 14, that is, the first and second cylinder holes 6, 8. A third bead 16 is provided in between. Then, as shown in FIG.
The meeting parts 18, 18, which are both ends of the bulging part 16a, are
It is configured to move from the conventional position shown by the dotted chain line to the position shown by the solid line and approach the bolt hole 10, which is the fastening part, so that the distance between the fastening bolt hole and the bead is approximately the same. At this time, the bolt hole 10
As is clear from FIGS. 1 and 2, the meeting portion 18 of the third bulging portion 16a of the third bead 16 between the first and second cylinder holes 6 and 8 is located at a desired location on the substrate 4, for example.
18 , that is, on the side away from the third bead 16 .

Next, the effect will be explained.

In the metal gasket 2 which is interposed between the joint surface between the cylinder head and the cylinder block with a fastening bolt (not shown), a substrate 4 which is an elastic metal plate is used.
The gap caused by the distortion of the bonding surface is sealed by the beads formed in the first
A good seal line is formed on the second beads 12 and 14, and leakage of oil and gas at the joint surfaces is prevented.

In addition, by bringing the meeting parts 18, 18, which are both ends of the third bulging part 16a of the third bead 16, close to the bolt hole 10, which is a fastening part, the inside of the first and second cylinder holes 6, 8 during engine operation is increased. The force that would otherwise cause a leak due to the pressure difference is blocked at the meeting portions 18, 18. In other words, the fastening bolt (not shown)
Due to the pressing force, the meeting portions 18, 18 are sufficiently flattened and a strong seal line is generated, so that a reliable seal can be achieved. Furthermore, the connecting portions 18, 18 of the bulging portions of each bead are spaced apart from the vicinity of the first and second cylinder holes 6, 8 and brought closer to the bolt hole 10, which is the fastening portion, so that the first and second cylinder holes By simplifying the bead shape located near 6 and 8, the influence of the pressure difference between the cylinders becomes less likely to occur, and leakage between the cylinders can be prevented.

By locating the meeting parts 18, 18 near the bolt holes 10, 10, which are fastening parts, the distance between the first and second cylinder holes 6, 8 can be narrowed, and the engine can be made compact and lightweight. There are some effects that can be done.

[Effect of idea]

As explained in detail above, according to this invention, the connecting part of the bead formed on the metal gasket is brought close to the fastening part so that the distance between the fastening bolt hole and the bead is approximately the same, so when fastening The pressing force can forcibly flatten the bead at the meeting part and separate the meeting part from between the cylinders, thereby preventing the seal line from being cut and improving the sealing performance at the meeting part. This has the effect of reliably preventing leaks such as blow-throughs.

[Brief explanation of the drawing]

1 and 2 show an embodiment of this invention, with FIG. 1 being a schematic plan view of a metal gasket, and FIG. 2 being an enlarged view of the portion in the direction of the arrow in FIG. 3 and 4 show the prior art of this invention, FIG. 3 being a schematic plan view of a metal gasket, and FIG. 4 being an enlarged sectional view taken along the line - in FIG. In the figure, 2 is a metal gasket, 4 is a substrate,
6 is the first cylinder hole, 8 is the second cylinder hole, 12
14 is a first bead, 14 is a second bead, 16 is a third bead, and 18 is a meeting portion.

Claims (1)

[Scope of utility model registration request] In a metal gasket that achieves sealing by forming beads on an elastic metal plate, beads are provided to surround and seal a plurality of cylinder holes provided in the elastic metal plate, and fastening bolt holes are drilled at desired locations in the elastic metal plate. A metal gasket characterized in that a meeting portion of the bead is formed close to a portion of the fastening bolt hole so that the distance between the fastening bolt hole and the bead is approximately the same.