JP2003240122A - Gasket mounting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high sealability without deforming a mounted member of low rigidity. <P>SOLUTION: In this gasket mounting structure wherein a gasket 1 is mounted in a state of being held in connecting parts 2a, 3a of two members one of which 3 has the rigidity lower than the other member 2, and a mounting part 5 of the gasket 1 is inserted into a mounting groove 4 formed on the connecting part 3a of the member 3 of two members 2, 3, a radius of curvature of a top part 10 of the mounting part 5 of the gasket 1 is smaller than a radius of curvature of a corner part 13 of a bottom face 11 and a side face 12 of the mounting groove 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasket mounting structure that is sandwiched between two members to seal them. More specifically, the present invention relates to improvements in the shapes of the gasket and the mounted member.

[0002]

2. Description of the Related Art In order to seal a joint portion between two members which are pressed against each other and joined together, a gasket is sandwiched and mounted on the joint portion. For example, in an automobile engine, a gasket is mounted between a cylinder head and a cylinder head cover, and between a cylinder block and a cover such as a front cover (chain cover). This seals the engine to prevent engine oil from leaking. The cross-sectional shape of the gasket 101 is substantially T-shaped as shown in FIG. 5, for example. This gasket 1
01 is a mounting portion 104 that is inserted into the mounting groove 103 of the cylinder head cover 102, and a flange portion 106 that is formed at the end of the mounting portion 104 on the cylinder head 105 side.
A seal projection 107 is formed on the end surface on the cylinder head 105 side. The mounting groove 103 of the cylinder head cover 102 has a rectangular cross section or a bottom surface 108 and a side surface 1.
The corner 110 with 09 is formed in a slightly rounded shape.

By the way, conventionally, the block and cover of the engine are generally made of metal, but in recent years, the cover may be made of plastic in order to reduce the weight of the automobile, reduce vibration, and reduce the cost. Also in this case, the cylinder head cover 102 made of plastic and the cylinder head 1 made of metal
The engine is sealed by interposing a gasket 101 with the engine 05. Here, since the mounting portion 104 is difficult to be crushed when the gasket 101 has a short and stubby shape,
The cylinder head cover 102 may be bent so as to float up due to the reaction force of the gasket 101 between the adjacent tightening bolts. If such deformation occurs, the sealing property of the gasket 101 will deteriorate.

Therefore, when the rigidity of the cylinder head cover 102 is comparatively small, the gasket 104 is formed by making the mounting portion 104 of the gasket 101 vertically long and ensuring a sufficient gap between the mounting groove 103 and the mounting portion 104. Cylinder head cover 10 by suppressing the reaction force of 101 to a low level
The deformation of 2 is prevented.

[0005]

However, in the mounting structure of the gasket 101 described above, the mounting groove 103 of the cylinder head cover 102 has a rectangular cross section or the bottom surface 1.
Since the corner portion 110 between the 08 and the side surface 109 has a slightly rounded shape, the top portion 111 of the mounting portion 104 is not arranged in the center of the mounting groove 103 due to a slight deviation when the cylinder head cover 102 is assembled. If compressed, the top portion 111 of the gasket 101 may come into line contact with not only the bottom surface 108 of the mounting groove 103 but also the side surface 109. That is, the top portion 111 of the mounting portion 104 has the mounting groove 10
There is a risk of intermittent line contact with the inner surface of No. 3 by the two contact lines 112. When the two contact lines 112 make line contact in this manner, the pressure between the mounting portion 104 and the inner surface of the mounting groove 103 is dispersed, and a sufficient contact surface pressure cannot be obtained, and it is difficult to secure the sealing property. Become.

Therefore, an object of the present invention is to provide a gasket mounting structure which can obtain a high sealing property without deforming a member to be mounted having a low rigidity.

[0007]

In order to achieve the above object, the invention according to claim 1 interposes a gasket at a joint portion of two members in which one member is lower in rigidity than the other member. In addition, in the gasket mounting structure in which the gasket mounting portion is inserted into the mounting groove formed in the coupling portion of one of the two members, the curvature radius of the top of the gasket mounting portion is equal to that of the mounting groove. It is smaller than the radius of curvature of the corner between the bottom surface and the side surface.

Therefore, even when the top of the mounting portion is not arranged in the center of the mounting groove due to slight displacement of the gasket and the mounted member when the cover is assembled,
The top of the mounting part always comes into line contact with one line. As a result, the pressure is concentrated on the contact portion, so that a sufficient contact surface pressure can be obtained and a high sealing property can be secured.

The invention according to claim 2 is the gasket mounting structure according to claim 1, wherein the bottom surface of the mounting groove has an arcuate cross section. Therefore, even when the top portion of the mounting portion is compressed without being placed in the center of the mounting groove due to a slight deviation when the cover is assembled, the top portion of the mounting portion is guided to the bottom surface of the mounting groove and moves to the central portion. Like Thereby, a more stable sealing property can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described below in detail based on an example of an embodiment shown in the drawings. As shown in FIGS. 1 to 3, in the gasket 1 mounting structure of the present embodiment, the gasket 1 is interposed between a cylinder head 2 and a cylinder head cover 3 of an automobile engine. In this gasket 1 mounting structure, the cylinder head cover 3 which is one member has a rigidity lower than that of the cylinder head 2 which is the other member, and the gasket 1 is interposed between the joint portions 2a and 3a of the two members 2 and 3. In addition, the mounting portion 5 of the gasket 1 is inserted into the mounting groove 4 formed in the coupling portion 3a of the cylinder head cover 3. The radius of curvature R1 of the top portion 10 of the mounting portion 5 of the gasket 1 is smaller than the radius of curvature R2 of the corner portion 13 between the bottom surface 11 and the side surface 12 of the mounting groove 4.
Therefore, even if the top portion 10 of the mounting portion 5 is compressed without being arranged in the center of the mounting groove 4 due to a slight deviation or the like when the cylinder head cover 3 is assembled, as shown in FIG. Is always in line contact with the corner portion 13 between the bottom surface 11 and the side surface 12 of the mounting groove 4 by one contact line 14. As a result, the pressure is concentrated on the contact portion, so that a sufficient contact surface pressure can be obtained and a high sealing property can be secured.

The central portion of the bottom surface 11 of the mounting groove 4 is flat. Therefore, when the cylinder head cover 3 is attached to the cylinder head 2 while the gasket 1 is positioned in the center of the mounting groove 4, the top portion 10 of the mounting portion 5 comes into close contact with the center portion of the bottom surface 11 of the mounting groove 4 and is compressed. Become so.

The gasket 1 facing the connecting portion 2a of the cylinder head 2 is provided with seal projections 6 and 8. Therefore, the sealing projections 6 and 8 can enhance the sealing performance between the gasket 1 and the cylinder head 2 facing the gasket 1. The seal protrusions 6 and 8 here are formed by an inner seal protrusion 6 formed on the engine inner side I from the center and an outer seal protrusion 8 formed on the outer O side from the center. Each of the seal projections 6 and 8 is a projection formed on the end surface of the gasket 1 and having a substantially triangular cross section. The seal protrusions 6 and 8 are not limited to protrusions having a substantially triangular cross section, and may have lip shapes.

The gasket 1 is, for example, JIS HS60.
It is made of an elastomer such as acrylic rubber having a certain hardness. The mounting portion 5 has a substantially wedge-shaped cross section. Further, the gasket 1 is provided with flange portions 9 and 9 which are formed at an end portion of the mounting portion 5 on the cylinder head 2 side and project inward and outward of the engine.

The above-mentioned gasket 1 is attached to the cylinder head 2
The operation when mounted between the cylinder head cover 3 and the cylinder head cover 3 will be described below.

The cylinder head cover 3 is assembled to the cylinder head 2 with the mounting portion 5 of the gasket 1 inserted into the mounting groove 4 of the cylinder head cover 3. At this time,
The front and back of the gasket 1 can be easily recognized by the flange portions 9, 9. And the cylinder head cover 3
The connecting portions 3a, 2a between the cylinder head 2 and the cylinder head 2 are tightened with bolts and nuts, etc.

At this time, the mounting portion 5 of the gasket 1 is pushed into the mounting groove 4 and crushed. Thereby, the space between the cylinder head cover 3 and the gasket 1 can be sealed. Here, when the mounting position of the gasket 1 is displaced from the central portion of the mounting groove 4 due to a dimensional error or an assembly error, the top portion 10 of the mounting portion 5 is displaced from the central portion of the bottom surface 11 of the mounting groove 4. May be compressed up to. In this case, the top 10 of the mounting portion 5 is pressed against the corner 13 of the mounting groove 4, but the radius of curvature R1 of the top 10 of the mounting portion 5 is increased.
Is smaller than the radius of curvature R2 of the corner portion 13 of the mounting groove 4, the top portion 10 of the mounting portion 5 is always in line contact with the corner portion 13 of the mounting groove 4 by one contact line 14. As a result, the pressure is concentrated on the contact portion, so that a sufficient contact surface pressure can be obtained, and a high sealing property can be secured between the cylinder head cover 3 and the gasket 1.

Since the mounting portion 5 has a relatively elongated shape and a small volume for its length, the reaction force to the cylinder head cover 3 is small. Therefore, the cylinder head cover 3
Even if is made of plastic and has low rigidity, it can be prevented from being bent by the reaction force of the gasket 1. Therefore, the plastic cylinder head cover 3 does not float up from the cylinder head 2, and it is possible to prevent the sealing performance from deteriorating.

Cylinder head cover 3 made of plastic
Even when the heat is deformed by the heat of the engine and floats up from the cylinder head 2, the mounting portion 5 is relatively elongated and has a small reaction force, so that the crushing margin can be increased, so that the mounting portion 5 can extend and easily follow the cylinder head cover 3. You can As a result, it is possible to prevent the sealing performance from deteriorating.

On the other hand, the sealing projections 6 and 8 of the gasket 1
Are pressed against the connecting portion 2a of the cylinder head 2 and brought into close contact therewith. Thereby, the space between the cylinder head 2 and the gasket 1 can be satisfactorily sealed.

The above-described embodiment is an example of the preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the central portion of the bottom surface 11 of the mounting groove 4 is flat, but the present invention is not limited to this. For example, as shown in FIG. 4, the entire bottom surface 11 of the mounting groove 4 has an arcuate cross section. You may do it. That is, the planar bottom surface 11 in the embodiment shown in FIG.
Are directly connected. According to this, even if the top portion 10 of the mounting portion 5 is compressed without being arranged in the center of the mounting groove 4 due to a shift at the time of assembling the cylinder head cover 3, the top portion 10 is guided to the bottom surface 11 of the mounting groove 4. To move to the central part. Therefore, a more stable sealing property can be obtained.

Further, in the above-described embodiment, the respective seal projections 6 and 8 are arranged inside and outside with the center of the gasket 1 interposed, but the present invention is not limited to this, and the seal projections 6 and 8 are arranged around the apex of one of the seal projections 6 and 8. Alternatively, both seal protrusions 6 and 8 may be arranged so as to be biased to either the inner I side or the outer O side. Furthermore, in the above-described embodiment, the inner seal protrusion 6 and the outer seal protrusion 8 are formed on the surface of the gasket 1 facing the cylinder head 2, but the present invention is not limited to this, and only a single seal protrusion may be formed. May be. In either case, the seal projection can prevent the oil from leaking inside the engine I.

In the above embodiment, the mounting groove 4 is formed in the connecting portion 3a of the cylinder head cover 3 and the connecting portion 2a of the cylinder head 2 is formed flat, but the present invention is not limited to this. The attachment groove 4 may be formed in the connecting portion 2a and the connecting portion 3a of the cylinder head cover 3 may be formed flat. Further, although the mounting portion 5 has a substantially wedge-shaped cross section in the present embodiment, it is not limited to this and may have a rectangular shape.

Furthermore, in each of the above-mentioned embodiments, the gasket 1 is supposed to be mounted between the cylinder head 2 and the cylinder head cover 3 of the engine of the automobile, but the invention is not limited to this, and the gasket 1 is mounted on other parts of the engine. Alternatively, it may be mounted between two members other than the engine. In either case, the inside and outside of the two members can be effectively sealed.

[0024]

As is apparent from the above description, according to the gasket mounting structure of claim 1, the radius of curvature of the top of the gasket mounting portion is determined from the radius of curvature of the corners between the bottom surface and the side surface of the mounting groove. Since it is made small, even if the top of the mounting part is not placed in the center of the mounting groove when the cover is assembled and the cover is compressed, the top of the mounting part always comes into line contact with the corner of the mounting groove by one line. Like With this, the pressure is concentrated on the contact portion, so that a sufficient contact surface pressure can be obtained,
A high sealing property can be secured.

Further, according to the gasket mounting structure of the second aspect, since the bottom surface of the mounting groove has an arcuate cross section, the top of the mounting portion is compressed at the center of the mounting groove when the cover is assembled. Even at this time, the top of the mounting portion is guided by the bottom surface of the mounting groove and moves to the center. Thereby, a more stable sealing property can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a gasket mounting structure of the present invention.

FIG. 2 is a cross-sectional view showing a state cut along line II-II in FIG.

FIG. 3 is a perspective view showing a state where a gasket is mounted between a cylinder head and a cylinder head cover of an automobile engine.

FIG. 4 is a cross-sectional view showing another embodiment of the gasket mounting structure.

FIG. 5 is a perspective view showing a conventional gasket mounting structure.

[Explanation of symbols]

1 gasket 2 Cylinder head (other member) 2a connecting part 3 Cylinder head cover (one member) 3a connecting part 4 mounting groove 5 Mounting part 6 Inner seal protrusion (seal protrusion) 8 Outside seal protrusion (seal protrusion) 10 top 11 Bottom 12 sides 13 corners

Claims (2)

[Claims] 1. A gasket is sandwiched between a connecting portion of two members, one member of which has a lower rigidity than the other member, and is formed in the connecting portion of one of the two members. In a gasket mounting structure in which the mounting portion of the gasket is inserted into the mounted mounting groove, the radius of curvature of the top portion of the mounting portion of the gasket is smaller than the radius of curvature of the corner portion between the bottom surface and the side surface of the mounting groove. A gasket mounting structure characterized by 2. The gasket mounting structure according to claim 1, wherein the bottom surface of the mounting groove has an arcuate cross section.