JP2514182Y2 - Gasket for cylinder head cover - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head cover gasket arranged between a cylinder head and a head cover of an automobile engine.

[0002]

2. Description of the Related Art A gasket is sandwiched between a cylinder head and a head cover in an automobile engine to prevent oil leakage and reduce vibration of the head cover.
As an example of this gasket, the one shown in FIG. 3 is known. The gasket body 2 of the gasket 10 has a substantially convex cross section, and the upper portion 2a is rounded while the bottom portion 2b is a flat surface. Then, the inner side surface 2c has a gentle curved surface, and the raised portion 2e is provided. Also, the outer surface 2d
Has a substantially flat shape, and when the gasket main body 2 is pressed by the head cover 5, the pressing force is concentrated on the inner portion to enhance the line sealability, and the outer surface 2d is not provided with a ridge so that the bottom portion 2b The width of each of the cylinder head 4 and the head cover 5 can be narrowed so that the width of each end can be narrowed.

When mounting the gasket 10, the upper portion 2a is fitted to the holding portion 5b having an inverted U-shaped cross section provided on the lower end portion of the head cover 5, and the bottom portion 2b is attached to the upper end surface 4a of the cylinder head 4. To place. Then, a stud bolt is inserted into a bolt insertion hole (not shown) provided in the head cover 5, and a cap nut is screwed through a washer seal to fasten the head cover 5 to the cylinder head 4.

As a result, the bottom portion 2b of the gasket body 2 is pressed against the peripheral upper end surface 4a of the cylinder head 4, and the airtightness is maintained by the action of a line seal. Therefore, it is possible to prevent oil leakage due to engine start-up and generation of abnormal noise due to vibration.

Further, as a modified example of this type of gasket, a radiant heat shielding fin is projected from the bottom of the outer peripheral portion of the gasket body in the horizontal direction to block the radiant heat from the exhaust manifold and There has been proposed a cylinder head gover gasket that prevents a portion from deteriorating due to thermal cracks (see Japanese Utility Model Laid-Open No. 62-158146).

[0006]

By the way, in the conventional gasket 10 described above, when the cylinder head 4 and the head cover 5 are both in pressure contact with each other, the cylinder head 4 is
The upper end surface 4a of the head cover 5 and the inner and outer side walls 5c and 5d of the holding portion 5b of the head cover 5 are joined together by three points.
Since the pressing force acts in the direction of the center of, the rigidity is increased and the sealing performance is improved. However, when the head cover 5 is pressed against the cylinder head 4 when the gasket main body 2 is mounted, the gasket main body 2 may not be sufficiently fitted, or the bottom portion 2b in contact with the upper end surface 4a of the cylinder head 4 may be displaced. , There is a case where the pressing force does not concentrate at the center but acts toward the inner side having the curved surface. Then, Fig. 3
As shown by the phantom line, the bottom portion 2b falls into the cylinder and the gasket body 2 is deformed. Along with this, the sealability between the gasket body 2 and the cylinder head 4 is impaired, causing oil leakage and abnormal noise.

In order to eliminate this problem as much as possible, a visual inspection is usually carried out, but since the gap 6 between the cylinder head 4 and the head cover 5 is small (about 1 to 2 mm), it is deformed. It was extremely difficult to find the collapse due to. Therefore, if left in this state, there is a problem that the mist is diffused into the atmosphere in addition to oil leakage due to deterioration of the sealing property of the gasket 10.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to make it possible to easily inspect the mounting state of the gasket from the outside and to prevent the occurrence of oil leakage and abnormal noise due to the abnormal mounting of the gasket. There is.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, an outer surface of a gasket body is a flat shape which is substantially vertical, and an inner surface is a gently curved surface projecting inward. Is a reverse cross section U provided at the lower end of the head cover.
Cylinder head cover gasket that fits in a V-shaped holding part, while the bottom part is placed on the upper end surface of the cylinder head, and in the mounted state there is a small gap between the outer peripheral lower end of the head cover and the outer peripheral upper end of the cylinder head. In the above, a protruding edge that extends outwardly over the entire circumference of the gasket body is integrally formed on the bottom side of the outer peripheral portion of the gasket body.

[0010]

In the present invention, when mounting the gasket, the head of the gasket is fitted to the inverted U-shaped holding portion of the head cover. Then, the head cover is attached to the cylinder head in a state where the bottom of the gasket is pressed against the end surface of the cylinder head. Then, a pressing force acts on the gasket and further concentrates in the center direction, so that the gasket is given rigidity. At this time, the protruding edge extends outward from the small gap between the head cover and the cylinder head. However, when the mounting state of the gasket is abnormal and the bottom portion is displaced inward, the protruding edge remains in the head cover or only part of it is exposed to the outside through a small gap. Therefore, by visually recognizing this state, the operator can discover the deformation and the positional shift inside the gasket.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a cylinder head cover gasket, and FIG. 2 is an overall configuration diagram of the gasket.

This gasket 1 has a gasket body 2 sandwiched between a cylinder head 4 and a head cover 5,
It is configured to seal the cylinder chamber. Although not shown, the cylinder head 4 has an exhaust manifold, and has an upper end surface 4a formed in a flat shape. A plurality of unillustrated stud bolts are erected at the center of the cylinder head 4. The head cover 5 has a U-shaped portion 5a formed at a lower end thereof, and is connected to the U-shaped portion 5a and has an inverted U-shaped holding portion 5a.
b is provided. Further, the head cover 5 is formed with a bolt insertion hole corresponding to the position of the stud bolt.

The gasket body 2 has a substantially convex cross section, the upper portion 2a is rounded so that it can be fitted on the inner peripheral surface of the holding portion 5b, and the bottom portion is flat. In addition, the inner side surface 2c of the gasket body 2 has the inner side wall 5 of the holding portion 5b.
It is gently curved along c and has a raised portion 2e on the lower side. Further, the outer surface 2d of the gasket body 2 is substantially flat so as to be along the outer surface 5d of the holding portion 5b, and the bottom portion 2
A protruding edge 3 is integrally formed on the b side. This protruding edge 3
Extends outward in the horizontal direction, is provided over the entire outer periphery of the gasket body 2, and is configured to be kept linear along the length direction of the gasket body 2 in a normally mounted state. ing.

As shown in FIG. 1, the protruding edge 3 has a small gap (usually 1) between the head cover 5 and the cylinder head 4.
~ 2 mm) 6 is formed so as to project sufficiently outward.

Further, as shown in FIG. 1, the protruding edge 3 is provided so as to be located slightly above the bottom surface of the gasket body 2, and the protruding edge 3 is affected by the pressing force when the gasket 1 is pressed and held. It is configured so as not to reach the outside and to project outward from the small gap 6 in a natural state.

When mounting the above-mentioned cylinder head cover gasket 1, first, the head cover 5 is attached.
The upper portion 2a of the gasket body 2 is fitted to the holding portion 5b of the above. Next, the bottom portion 2b of the gasket body 2 exposed from the lower end 5e of the head cover 5 is placed on the upper end surface 4a of the cylinder head 4. At this time, a stud bolt is inserted into a bolt insertion hole (not shown) of the gasket body 2, a cap nut is screwed into the upper end of the protruding stud bolt through a washer seal, and the head cover 5 is fastened to the cylinder head 4. As a result, the bottom portion 2b of the gasket body 2 is pressed against the upper end surface 4a of the cylinder head 4 and the cylinder chamber is sealed by the line sealing action. In this state, the lower end 5e of the holding portion 5b of the head cover 5 and the cylinder head 4 are
Although a small gap 6 is formed between the upper end surface 4a and the upper end surface 4a, since the entire outer circumference is sealed by the gasket body 2, high airtightness is maintained.

By the way, when the head cover 5 is fastened, the gasket main body 2 moves the upper end surface of the cylinder head 4 by 4
The pressing force toward the center is received by a and the inner wall 5c and the outer wall 5d of the head cover 5. Therefore, the gasket body 2 is provided with rigidity, and the protruding edge 3 on the bottom portion 2b side is kept in a horizontally protruding state together with the shape retention. However, if the gasket body 2 is not firmly attached, and if, for example, the holding portion 5b is not sufficiently fitted or the bottom portion 2b is displaced, it will act in the center direction when a pressing force is applied. Instead, it mainly acts as a relief force on the raised portion 2e side, and the inner side surface 2c may fall into the cylinder chamber. Conventionally, such a deformation is hard to be detected from the outside, and if left as it is, a gap is created between the gasket 2, the cylinder head 4 and the head cover 5 to lose airtightness. However, the gasket 1 of the present embodiment is
When the inner side surface 2c of the gasket body 2 including e is in a state of falling down, the protruding edge 3 at that portion is the small gap 6
It is immediately discovered that something is wrong because the amount of protrusion is small even if it is located inwardly inward or even outside the small gap. Therefore, by modifying the gasket body 2 to a normal state, that is, a sandwiched state in which the protruding edge 3 is evenly projected to the outside over the entire circumference, the gasket body 2 is fixed to the cylinder head 4 and the head cover 5. It can be properly placed in between.

[0018]

As described above, according to the present invention, since the protruding edge that extends horizontally in the entire circumference of the gasket main body is integrally formed on the bottom side of the outer peripheral portion of the gasket main body, the gasket is provided with the cylinder head and the head cover. By visually recognizing the shape exposed to the outside of the protruding edge when it is sandwiched between and, it is possible to confirm whether the gasket body is properly arranged, and if it is abnormal, it can be immediately corrected. Therefore, the gasket mounting work does not require any skill and can be performed properly at all times, so that high airtightness is maintained, and problems such as oil leakage and abnormal noise due to improper mounting are prevented as in the past. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cylinder head cover gasket showing an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of the gasket.

FIG. 3 is a cross-sectional view of a conventional cylinder head cover gasket.

[Explanation of symbols]

 1 gasket 2 gasket body 2a upper part 2b bottom part 3 protruding edge 4 cylinder head 5 head cover

Claims (1)

(57) [Scope of utility model registration request] 1. An outer surface of the gasket body is a substantially vertical flat shape, an inner surface is a gently curved surface projecting inward, and an upper portion is provided at a lower end portion of the head cover with an inverted cross section U.
Cylinder head cover gasket that fits in a V-shaped holding part, while the bottom part is placed on the upper end surface of the cylinder head, and in the mounted state there is a small gap between the outer peripheral lower end of the head cover and the outer peripheral upper end of the cylinder head. The gasket for a cylinder head cover, characterized in that a protruding edge extending outwardly over the entire circumference of the gasket body is integrally formed on the bottom side of the outer peripheral portion of the gasket body.