JP2015197171A - cylinder head gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent concentration of stress on both end portions of each of cutting lines on a gasket base of a lowermost layer or an uppermost layer, and generation of cracking on both end portions, in cutting the gasket base in a stacked state so that a pair of cutting lines are formed, and simultaneously projecting the same from the base of the lowermost layer or uppermost layer.SOLUTION: A cylinder head gasket 1 is configured by stacking three sheets of gasket bases 2-4, and their connecting parts 5 are integrally connected. An upper face of the gasket base 2 and a lower face of the gasket base 3 as the connecting parts 5 are provided with rubber coating 11. When the connecting parts 5 are cut by a pressing cutting mechanism not shown in a drawing in a state of forming a pair of cutting lines 5A, and connected while retracted downward, concentration of stress on both end portions of the cutting lines 5A can be suppressed, and generation of cracking can be prevented by the rubber coating 11.

Description

  The present invention relates to a cylinder head gasket, and more particularly, to a cylinder head gasket configured by laminating a plurality of gasket substrates, and relates to an improvement in a connecting portion of the plurality of gasket substrates.

Conventionally, at least two gasket substrates each having a combustion chamber hole are provided, and the plurality of gasket substrates are cut at the same time in a stacked state so as to form a pair of cutting lines so as to form a pair of cutting lines. A cylinder head gasket in which the plurality of gasket substrates are integrally connected is known (for example, Patent Documents 1 to 3). Such a conventional connecting method is generally called “lance lock”.
Conventionally, it has been proposed to partially cover a portion of a gasket substrate where a full bead is formed with a coating (Patent Document 4). However, in such a conventional cylinder head gasket, the connection portion by the lance lock is not an object of coating (see Patent Documents 1 to 3).

JP-A-6-281101 JP 2001-336638 A JP 2004-251370 A Japanese Utility Model Publication No. 62-177963

As described above, in the conventional cylinder head gasket, a coating is not applied to the connection portion of the gasket substrate. Therefore, in the conventional cylinder head gasket, the following problems occur when the laminated gasket substrates are connected by a lance lock. That is, when the laminated gasket substrate is cut so as to form a pair of cutting lines and at the same time protrudes from the lowermost layer or the uppermost layer substrate, it is placed at both ends of each cutting line in the lowermost layer or the uppermost layer gasket substrate. There was a problem that stress was concentrated and cracks were likely to occur at both ends (see FIG. 5). As described above, when a crack occurs in the connection portion, there is a problem in that the crack expands with time and the sealing performance of the cylinder head gasket is deteriorated.
In addition, if coating is applied to the entire upper and lower surfaces of each gasket substrate including the connection portion by the lance lock, cracks will not occur in the connection portion by the lance lock, but as described above, only the bead location etc. in the gasket substrate In the conventional gasket in which the coating is partially applied to the gasket, it has not been considered to apply the coating to the connection portion of the gasket substrate.

In view of the above-described circumstances, the present invention includes at least two gasket substrates each having a combustion chamber hole, and an annular coating is applied to the uppermost gasket substrate so as to surround the combustion chamber hole. The lowermost gasket substrate is provided with an annular coating surrounding the combustion chamber hole, and the plurality of gasket substrates are cut in a stacked state so as to form a pair of cutting lines and below or In the cylinder head gasket in which the plurality of gasket substrates are integrally connected by projecting upward,
A coating is applied to the connecting portion on the upper surface of the uppermost gasket substrate, and a coating is applied to the connecting portion on the lower surface of the lowermost gasket substrate.

  According to the above-described configuration, the coating portions are coated on the gasket substrates that are the uppermost layer and the lowermost layer, and thus the connection portions of the plurality of gasket substrates are cut and protruded so as to generate a pair of cutting lines. In this case, it is possible to suppress the stress from being concentrated on the both ends of the cutting line. Therefore, it is possible to prevent cracks from occurring at both ends of the cutting line, to prevent deterioration of the sealing performance, and to provide a cylinder head gasket having a long life.

The top view which shows one Example of this invention. Sectional drawing of the layer part which follows the II-II line | wire of FIG. The perspective view which shows the state which cut | disconnected the principal part along the III-III line | wire of FIG. Sectional drawing which shows the state before the connection of the principal part of FIG. The perspective view which shows the connection location in the conventional cylinder head gasket.

1 to 2, reference numeral 1 denotes a cylinder head gasket. The cylinder head gasket 1 is sandwiched between a cylinder head (not shown) and a cylinder block. It is designed to maintain a seal between them by being sandwiched between both members.
The cylinder head gasket 1 includes a gasket substrate 2 that is positioned at the uppermost layer and abutting with the joint surface of the cylinder head, a gasket substrate 3 that is positioned at the lowermost layer and abutting the joint surface of the cylinder block, and both of these gasket substrates 2, 3 is formed by laminating gasket substrates 4 arranged between 3.
The three gasket substrates 2 to 4 constituting the cylinder head gasket 1 are integrally connected to each other at a required connection location 5 by a conventionally known lance lock in a laminated state. In the present embodiment, there are a total of five connection points 5.

A plurality of combustion chamber holes 6 are formed in each gasket substrate 2 to 4 in accordance with the position of the cylinder bore of the cylinder block. In addition, a plurality of bolt holes 7 for inserting fastening bolts and water holes 8 for circulating cooling water are formed at required positions of the gasket substrates 2 to 4 and lubricating oil is circulated. For this purpose, an oil hole (not shown) is formed. Each of the gasket substrates 2 to 4 is manufactured from, for example, SUS301 or SUS304 having a thickness of about 0.2 mm.

The gasket substrate 4 located in the middle has a flat surface throughout. On the other hand, full beads 2B and 3B are formed in the uppermost gasket substrate 2 and the lowermost gasket substrate 3 so as to surround each combustion chamber hole 6 in an endless manner. The full bead 2B of the gasket substrate 2 is formed to bulge upward toward the cylinder head, while the full bead 3B of the gasket substrate 3 is formed to bulge downward toward the cylinder block. That is, the upper and lower full beads 2B and 3B are located symmetrically across the gasket substrate 4 located in the middle, and are formed at positions where they overlap when viewed in the plan view of FIG.
Further, the gasket substrate 2 and the gasket substrate 3 are formed with outer peripheral side full beads 2C and 3C so as to surround the entire three combustion chamber holes 6 and the full beads 2B and 3B from the outside. As shown in FIG. 2, the outer peripheral side full bead 2C of the gasket substrate 2 is formed in a circular arc shape that bulges toward the cylinder head, and the outer peripheral side full bead 3C of the gasket substrate 3 extends downward toward the cylinder block. It is formed to bulge out.

  Further, the locations of the full beads 2B and 3B and the locations of the outer peripheral beads 2C and 3C in the gasket substrates 2 and 3 are covered with a rubber coating 11. More specifically, the locations of the full bead 2B and the outer peripheral bead 2C on the upper surface (front surface) of the gasket substrate 2 that is the uppermost layer are covered with a coating 11 made of rubber. The portions of the full bead 3B and the outer peripheral bead 3C on the lower surface (back surface) of the gasket substrate 3 that is the lowest layer are also covered with a coating made of rubber. Thus, the annular coating 11 is partially applied to the upper surface of the gasket substrate 2 and the lower surface of the gasket substrate 3 so as to surround the combustion chamber hole 6. On the other hand, no coating is provided on the upper and lower surfaces of the gasket substrate 4 located in the middle. An elastomer may be used as a coating material instead of the rubber coating. The above configuration is not different from a conventionally known cylinder head gasket.

Thus, the present invention prevents the occurrence of cracks in the connecting portion 5 by improving the connecting portion 5.
That is, as shown in FIGS. 3 to 4, the rubber coating 11 is applied to the connection portion 5 on the upper surface (surface) of the gasket substrate 2 which is the uppermost layer. A rubber coating 11 is also applied to the connecting portion 5 on the lower surface (back surface) of the gasket substrate 3 which is the lowermost layer. The coating 11 at the connecting portion 5 of the gasket substrate 2 is provided in the same process when the coating 11 is applied to the full bead 2B and the outer bead 2C on the gasket substrate 2. Similarly, the coating 11 at the connection portion 5 of the gasket substrate 3 is provided in the same process when the coating 11 is applied to the gasket substrate 3 on the full bead 3B and the outer peripheral bead portion 3C. On the other hand, as shown in FIG. 4, the coating is not applied to the connection portion 5 in the gasket substrate 4 serving as an intermediate layer. As described above, the five coupling points 5 in the cylinder head gasket 1 are formed on the upper surface (front surface) of the gasket substrate 2 as the uppermost layer and the lower surface (back surface) of the gasket substrate 3 as the lowermost layer. Is provided.
4 shows a state before the connecting portion 5 is connected by a press cutting mechanism (not shown), and FIG. 3 shows that the three gasket substrates 2 to 4 to be the connecting portion 5 are pressed by the press cutting mechanism. It shows a state after being connected so that the pair of cutting lines 5A can be cut and then retracted.

In the cylinder head gasket 1 configured as described above, a coating 11 is applied to the upper surface of the uppermost gasket substrate 2 at the connection location 5, and a coating is applied to the lower surface of the lowermost gasket substrate 3 at the connection location. (See FIGS. 4 and 3). Therefore, after laminating each of the three gasket substrates 2 to 4, each connecting portion 5 is cut by a pair of upper and lower press cutting mechanisms to produce a pair of cutting lines 5 A and protrudes downward. When connected, the stress can be suppressed from concentrating at both ends of the cutting line 5A in the gasket substrate 3 as the lowermost layer. Therefore, it is possible to prevent cracks from occurring at both ends of the cutting line 5A, to prevent the sealing performance of the cylinder head gasket 1 from being lowered, and to provide the cylinder head gasket 1 having a long life. .

In the above-described embodiment, the coating is not provided on the upper surface and the lower surface of the gasket substrate 4 of the intermediate layer at the connection location 5, but the coating is applied to the upper surface or the lower surface of the connection location 5 in the gasket substrate 4. The coating may be provided on both the upper surface and the lower surface. Even with such a configuration, it is possible to obtain the same operation and effect as the above-described embodiment.
In the above-described embodiment, the case where the present invention is applied to a cylinder head gasket configured by stacking three gasket substrates 2 to 4 is described. The present invention can also be applied to a cylinder head gasket. Even in that case, the same coating 11 as that of the above-described embodiment is applied to the connection portion 5 in the gasket substrate as the uppermost layer and the gasket substrate as the lowermost layer.
Further, in the above-described embodiment, the connecting portion 5 of the three gasket substrates 2 to 4 is pressed and cut by a pair of upper and lower press cutting mechanisms, and protrudes downward. The present invention can also be applied to the case where the four connecting portions 5 are projected upward and connected.

1. Cylinder head gasket 2. Gasket substrate 3. Gasket substrate 4. Gasket substrate 5. Connection point 6. Combustion chamber hole 11. Coating

Claims (3)

At least two gasket substrates each having a combustion chamber hole are provided, and the uppermost gasket substrate is provided with an annular coating surrounding the combustion chamber hole, and the lowermost gasket substrate is provided with the combustion chamber. An annular coating is provided to surround the hole, and the plurality of gasket substrates are cut in a laminated state so that a required connecting portion can be formed as a pair of cutting lines and protruded downward or upward. In the cylinder head gasket in which a plurality of gasket substrates are connected together,
A cylinder head gasket, characterized in that a coating is applied to the connecting portion on the upper surface of the uppermost gasket substrate, and a coating is applied to the connecting portion on the lower surface of the gasket substrate that is the lowermost layer.   The said cylinder head gasket is comprised by laminating | stacking three gasket substrates, The coating was given to the at least upper surface or lower surface in the connection location of the gasket substrate located in the middle. Cylinder head gasket   The cylinder head gasket according to claim 1 or 2, wherein the coating is a rubber or elastomer coating.

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