JP2001295934A - Cylinder head gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head gasket 1 manufactured at a lower cost and having better sealing performance in comparison with a conventional one. SOLUTION: This cylinder head gasket 1 is composed of an inner side member 2 with combustion chamber holes 2A bored, and an outer side member 3 independent of the inner side member 2 and surrounding the inner side member 2. Full bead parts 2B are formed at the inner side member 2, while half bead parts 3D and bolt holes 3C are formed at the outer side member 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improvement in a cylinder head gasket.

[0002]

2. Description of the Related Art Conventionally, a cylinder head gasket including an inner side portion surrounding a combustion chamber hole and an outer side portion other than the inner side portion and made of different kinds of metals is known (for example, Japanese Patent Application Laid-Open No. H11-157556). JP-A-8-285080).
In the cylinder head gasket disclosed in the above publication, the inner side portion is made of a thin and low-hardness metal, while the outer side portion is made of a thick and high-hardness metal. Laser welding is performed on the entire area of the boundary portion with the side portion to connect them integrally.

[0003]

In the above-mentioned conventional cylinder head gasket, the inner member is fitted to the outer member and connected integrally by welding, so that the rigidity of the entire cylinder head gasket is increased. Is higher. If the rigidity of the entire cylinder head gasket is high, the cylinder head gasket is interposed between the cylinder block and the cylinder head. The inner side member and the outer side member (cylinder head gasket) move relative to the cylinder block and the cylinder head. For this reason, there is a disadvantage that the bead portion provided on the cylinder head gasket slides and wears on the cylinder block and the cylinder head, thereby deteriorating the sealing performance. Moreover, in the above-mentioned conventional cylinder head gasket, since the entire area of the boundary between the inner side portion and the outer side portion is welded, the manufacturing process is increased by that amount and the manufacturing cost of the cylinder head gasket is high. There was also a disadvantage of becoming. In view of such circumstances, the present invention is to provide a cylinder head gasket that is inexpensive to manufacture and has good sealing properties.

[0004]

That is, the present invention relates to a cylinder head gasket including a gasket substrate having a combustion chamber hole formed in accordance with a cylinder bore of an engine and a bead formed to surround the combustion chamber hole. The gasket substrate comprises an inner member having the combustion chamber hole formed therein, and an outer member formed separately from the inner member and surrounding the inner member. is there.

According to such a configuration, the rigidity of the entire cylinder head can be reduced by separating the inner side member and the outer side member. This allows
The relative movement amount due to thermal expansion between the cylinder head gasket, the cylinder head, and the cylinder block can be reduced. In other words, since the relative displacement between the cylinder head and the cylinder block and the cylinder head gasket can be reduced, the sliding of the bead portion formed on the cylinder head gasket can be suppressed, thereby suppressing the occurrence of poor sealing. Can be.
In addition, since the inner member and the outer member are separated from each other, it is not necessary to join both members by welding or the like in the process of manufacturing the cylinder head gasket. Cost can be reduced. Therefore, it is possible to provide a cylinder head gasket having a lower manufacturing cost and a better sealing property than the conventional one.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIGS. 1 to 3, a cylinder head gasket 1 is sandwiched between a cylinder head (not shown) and a cylinder block to seal therebetween. It is supposed to. Cylinder head gasket 1 of this embodiment
Unlike the conventional one, the conventional member comprises an inner member 2 located on the inner side and an outer member 3 surrounding the inner member 2, which are separated from each other. As shown in FIGS. 2 to 4, the inner member 2 is made of a single stainless steel thin plate, and the inner member 2 has three combustion chambers corresponding to the positions of the cylinder bores 4 a of the cylinder block 4. A hole 2A is formed. The inner member 2 is formed in a shape in which three circles are connected in series. The inner member 2 has a full bead portion 2B surrounding each combustion chamber hole 2A.

On the other hand, the outer member 3 is also made of a single thin stainless steel plate, and is formed in a substantially rectangular frame shape surrounding the inner member 2. The inner peripheral portion 3A of the outer member 3 is shaped to match the outer peripheral portion 2C (contour) of the inner member 2 so that the outer peripheral portion 2C of the inner member 2 is It is adapted to be fitted to the portion 3A with a little play. As a result, as shown in FIG.
At the boundary between C and the inner peripheral portion 3A of the outer member 3, a gap 5 is formed along the outer peripheral portion 2C (contour) of the inner member 2. An outer peripheral portion 3B (outline) of the outer member 3 is formed in a rectangular shape that matches the shapes of the upper surface of the cylinder block 4 and the lower surface of the cylinder head 6. A plurality of bolt holes 3C are formed at predetermined positions of the outer member 3. The outer side member 3 is formed with a half bead portion 3D surrounding the entire area along the inner peripheral portion 3A. Although not shown in the drawing, a half bead portion surrounding each bolt hole 5 is formed in the outer side member 3 at a position surrounding the bolt hole 5. As described above, the inner member 2 and the outer member 3 are both made of stainless steel plates, and the plate thicknesses of both members 2 and 3 are set to the same thickness. And FIG.
As shown in FIG. 5, when the inner member 2 is fitted to the outer member 3, the gap is formed at the boundary between the outer peripheral portion 2 </ b> C of the inner member 2 and the inner peripheral portion A of the outer member 3. 5 will be maintained. In this embodiment, the gap 5 formed at the boundary between the two members 2 and 3 is configured to be located above the annular concave portion 4b provided on the upper surface of the cylinder block 4 for introducing cooling water.

In the above construction, the cylinder head gasket 1 is interposed between the upper surface of the cylinder block 4 and the lower surface of the cylinder head 6 as shown in FIG. Sandwiched between. At that time, as described above, the gap 5 is located above the annular concave portion 4b of the cylinder block 4. Then, the lower surface of the full bead portion 2B of the inner side member 2 is in close contact with the upper surface of the cylinder block 4 to seal that portion, and the upper surfaces, which are both side portions of the full bead portion 2B, are in close contact with the lower surface of the cylinder head 6 so that Seal the parts. The outer edge of the half bead portion 3D of the outer member 3 is in close contact with the upper surface of the cylinder block 4 to seal the portion, and the outer member 3
The inner edge of the half bead portion 3D closely adheres to the lower surface of the cylinder head 6 to seal that portion.

After the cylinder head gasket 1 is interposed between the upper surface of the cylinder block 4 and the lower surface of the cylinder head 6, the cylinder block 4, the cylinder head 6 and the cylinder head gasket 1 are formed by the combustion gas in the cylinder bore 4a. Thermally expands. At this time, FIG.
, The cylinder block 4 and the cylinder head 6
Is thermally expanded outward from the cylinder bore 4a. On the other hand, the cylinder head gasket 1 has a low rigidity because the inner member 2 and the outer member 3 are divided,
The outer member 3 thermally expands substantially integrally with the cylinder block 4 and the cylinder head from the position shown by the imaginary line to the position shown by the solid line. Therefore, the inner member 2 and the outer member 3 that constitute the cylinder head gasket 1
Are thermally expanded substantially integrally with the cylinder block 4 and the cylinder head 6 sandwiching them. Thereby, when the cylinder head gasket 1, the cylinder block 4, and the cylinder head 6 thermally expand, the relative movement between the front and back surfaces of the cylinder head gasket 1 and the cylinder block 4 (cylinder head) can be suppressed to a small extent. Thereby, the sliding of the full bead portion 2B and the half bead portion 3D provided on the cylinder head gasket 1 can be suppressed, and the occurrence of a defective seal due to damage of those portions can be suppressed.
In addition, since the cylinder head gasket 1 of this embodiment is configured such that the inner member 2 and the outer member 3 are separated from each other, it is not necessary to join them integrally by welding or the like. The manufacturing process of the cylinder head gasket 1 can be simplified, and the manufacturing cost of the cylinder head gasket 1 can be reduced.

FIGS. 6 to 9 show an embodiment in which the material of the inner member 2 and the material of the outer member 3 of the cylinder head gasket 1 in the first embodiment are made different. That is, in the embodiment shown in FIG. 6, the inner member 2 is made of a stainless steel sheet as in the first embodiment, while the outer member 3 is made of a soft aluminum thin sheet. is there. Other configurations are the same as those of the first embodiment.

The embodiment shown in FIG.
Is made of a stainless steel thin plate, while the outer member 3 is formed by attaching graphite 3F in a thin film shape to the entire area of both front and back surfaces of an iron thin plate. In the embodiment shown in FIG. 7, the total thickness of the outer member 3 is the same as that of the inner member 2. Other configurations are the same as those of the first
This is the same as the embodiment.

The embodiment shown in FIG.
Is made of a stainless steel thin plate, and the outer member 3 is made of rubber 3G in the form of a thin film over the entire front and back surfaces of the iron thin plate.
Alternatively, talc is bonded with an aramid resin. In the embodiment shown in FIG.
Has the same thickness as the inner member 2.

The embodiment shown in FIG.
Is formed of a stainless steel thin plate, while the outer member 3 is formed of a synthetic resin. Other configurations are the same as those of the first embodiment. In the embodiment shown in FIGS. 6 to 9 described above, the same operation and effect as in the first embodiment can be obtained.

FIG. 10 shows a different embodiment of the present invention. In the embodiment shown in FIG. 10, the thickness of the inner member 2 in the first embodiment is changed to the outer side. Is made thicker than the plate thickness of the member. Other configurations are the same as those of the first embodiment. In such an embodiment, the same operation and effect as those of the first embodiment can be obtained. Further, in each of the embodiments shown in FIGS. 6 to 9, it is a matter of course that the thickness of the inner member 2 may be larger than the thickness of the outer member 3. In such an embodiment, the same operation and effect as those of the first embodiment can be obtained.

Next, in each of the above-described embodiments, the inner member 2 and the outer member 3 are completely separated from each other. Alternatively, the inner member 2 and the outer member 3 may be connected so as not to hinder relative movement. By partially connecting the two members in this way, handling such as transporting the gasket and assembling the gasket to the engine can be made equivalent to the conventional one. As such a coupling means, a conventionally known coupling method using a clinch as shown in FIG. 11 can be considered. That is, while the engagement concave portion 3H is formed in the inner peripheral portion 3A of the outer side member 3,
An engagement protrusion 2D that engages with the engagement recess 3H may be formed on the outer peripheral portion 3B of the inner member 2, and the engagement protrusion 2D may be engaged with the engagement recess 3H.

FIGS. 12 to 14 show connecting means by caulking instead of connecting means using clinch. That is, a substantially square overlapping portion 2E that protrudes outward is formed on the outer peripheral portion 2C of the inner member 2. When the inner member 2 is fitted to the outer member 3, the overlapping portion 2E overlaps the lower surface of the outer member 3. In this state, the overlapping portion 2E and the outer member 3 superposed thereon are partially cut in parallel from above by a punch, and the cut portion is pressed downward. As a result, the cut portion of the overlapping portion 2E and the outer member 3 that is overlapped with the overlapping portion 2E protrudes toward the lower surface,
This is the locking projection 11. The locking projection 11 projects below the lower surface of the inner member 2 and slightly engages with the lower surface of the inner member 2. by this,
The inner and outer members 2, 3 are partially connected. In each of the above embodiments, the case where the present invention is applied to the case where the inner member 2 and the outer member 3 are both one layer has been described, but the total thickness of the inner member 2 is The present invention is also applicable to a laminated gasket in which each of the inner member 2 and the outer member 3 is formed by laminating the same or a different number of substrates, as long as it is substantially the same as or thicker than that of the member 3. Can be applied. In each of the above embodiments, the inner member 2 has only the full bead portion 2B, and the outer member 3 has the half bead portion 3B.
Although only D is provided, the present invention is not limited to this. Needless to say, a plurality of beads may be used in combination as needed for each of the two members 2 and 3.

[0017]

As described above, according to the present invention, it is possible to provide a cylinder head gasket having a low manufacturing cost and a good sealing property.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is a plan view of an inner member 2 shown in FIG.

FIG. 3 is a plan view of an outer member 3 shown in FIG. 1;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1;

FIG. 5 is a sectional view showing a state in which a part of the cylinder head gasket 1 shown in FIG. 1 is thermally expanded.

FIG. 6 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 7 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 8 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 9 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 10 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 11 is a plan view showing coupling means for coupling the inner member 2 and the outer member 3;

FIG. 12 is a plan view showing coupling means for coupling the inner member 2 and the outer member 3;

FIG. 13 is a sectional view taken along the line III-III in FIG. 12;

FIG. 14 is a sectional view taken along the line IV-IV in FIG. 12;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylinder head gasket 2 ... Inner side member 2A ... Combustion chamber hole 2B ... Full bead part 3 ... Outer side member 3 3A ... Outer peripheral part 3B ... Outer peripheral part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eisaburo Goto 3-65 Midorigaoka, Toyota-shi, Aichi Prefecture Inside Daitoyo Kogyo Co., Ltd. (72) Inventor Yasumaro Takeda 3-65, Midorigaoka, Toyota-shi, Aichi Pref. In-house F term (reference) 3J040 AA01 AA12 BA01 EA07 EA08 EA15 EA17 FA01 HA02 HA17

Claims (6)

[Claims] 1. A cylinder head gasket comprising: a gasket substrate having a combustion chamber hole formed in accordance with a cylinder bore of an engine and a bead portion formed to surround the combustion chamber hole. A cylinder head gasket, comprising: an inner member formed with an inner member; and an outer member formed separately from the inner member to surround the inner member. 2. The cylinder head gasket according to claim 1, wherein a bead portion surrounding the combustion chamber hole is formed in the inner side member. 3. The method according to claim 1, wherein the inner member is made of a hard metal, and the outer member is made of a soft material softer than the inner member. Cylinder head gasket. 4. The cylinder according to claim 1, wherein a total thickness of the inner member is formed to be thicker than a total thickness of the outer member. Head gasket. 5. The cylinder head gasket according to claim 1, wherein the inner member and the outer member are partially connected by a connecting means. 6. A gap formed at a boundary between the inner side member and the outer side member is formed at a position corresponding to a concave portion into which cooling water is introduced on an upper surface of the cylinder block. The cylinder head gasket according to any one of claims 1 to 5.