JPH0318679Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to the structure of an intake manifold gasket used in an engine intake system.

(Prior Art) Conventionally, as an intake manifold gasket used in an engine intake system, an annular seal that is softer than the gasket body is attached to the periphery of the opening of the gasket body in which an opening that becomes the intake passage is formed. Some are known in which a material (for example, seal rubber) is attached.

In such conventional gaskets, the sealing material is attached to the surface of the gasket body around the opening, so if this gasket is inserted between the cylinder head and the intake manifold and tightened with a tightening bolt, , the sealing material receives most of the tightening force. When the engine is operated in this condition, the compressive load on the seal material changes due to thermal expansion, deflection, vibration, etc. of the cylinder head and intake manifold, causing deterioration of the seal material due to fatigue. However, there was a problem in that the airtightness of the opening decreased and gas leakage occurred.

In particular, as shown in FIG. 3, a cylinder system consisting of a cylinder block 20, cylinder heads 21, 21, and head covers 22, 22, that is, banks 23, 24, are arranged in a V-shape.
An air cleaner 25 is installed between these two bags 23 and 24.
In a V-type engine in which an intake manifold 26 is installed through gaskets 27, 27 to introduce outside air into the engine, the cylinder heads 21, 21 thermally expand at high temperatures and press strongly against each other through the intake manifold 26. Therefore, the cylinder head 21 and intake manifold 26
The gasket 27 between the gasket and the gasket receives a large compressive load (a compressive load in a direction perpendicular to the gasket contact surface). As a result, gaskets in V-type engines are subject to more severe operating conditions than in-line engines, and deterioration due to sealing material wear is significant.

Therefore, in Japanese Utility Model Application Publication No. 59-96346, an opening to serve as an air passage is formed in the gasket body,
It has been proposed to construct a gasket by providing an annular sealing member, which is softer than the gasket main body and has a core material embedded therein, on the inner circumferential surface of the opening to keep the passage airtight.

(Problem to be solved by the invention) However, in such a structure, if the center line between the gasket body and the core material of the sealing member is misaligned in the thickness direction, the thickness of the rubber portion above and below the core material will be Since the compressive force is different between the gaskets and the gasket, there is a problem that when the sealing member is installed between the cylinder head and the intake manifold, torsional force is applied to the joint (root) of the sealing member with the gasket body.

An object of the present invention is to provide an intake manifold gasket structure that prevents the sealing performance of the seal member from deteriorating by using a metal spacer.

(Means for Solving the Problems) The present invention comprises a gasket body in which an opening serving as an intake passage is formed, and an annular sealing member that is softer than the gasket body and provided on the inner peripheral surface of the opening. The above-mentioned gasket body is sandwiched by a metal spacer that protrudes less than the sealing member, and the metal spacer has a concave part in the contact surface that comes into contact with the intake passage constituting member. A metal spacer is attached to the gasket body by a strut weld in the recess.

(Function) In the installed state, the intake manifold gasket receives a compressive load, and the sealing member, which is softer than the metal spacer, compressively deforms up to the thickness of the metal spacer, but does not compress any further. . That is, most of the compressive load due to tightening of the tightening bolt of the intake manifold gasket is received by the gasket body via the metal spacer, and no excessive compressive load is applied to the sealing member.

During engine operation, the compressive load that the intake manifold gasket receives changes due to thermal expansion, deflection, vibration, etc. of the cylinder head and intake manifold, but most of this changing load is transferred to the gasket body via the metal spacer. receives.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

The intake manifold gasket 1 shown in FIGS. 1 and 2 has a gasket main body made of a highly rigid metal plate, and has openings 2A, 2B, 2C, 3A, 3B, and 3C forming first and second intake passages. 4
and an annular sealing member 5A, 5B, 5C which is softer than the gasket body 4 and is provided on the inner peripheral surface of each of the openings 2A, 2B, 2C, 3A, 3B, 3C. This intake manifold gasket 1
As shown in FIG. 3, it is installed at the joint surface between the cylinder head 21 and the intake manifold 26 of a V-type engine, and maintains the airtightness of the joint surface.

The gasket body 4 has the openings 2A, 2
The portions of B, 2C, 3A, 3B, and 3C excluding the periphery are sandwiched between metal spacers 9 and 10, which protrude less than the seal members 5A, 5B, and 5C from the gasket surface. The amount of protrusion Δt ₁ of the metal spacers 9 and 10 made of this metal material from the surface of the gasket body is determined by the amount Δt 1 of the metal spacers 9 and 10 made of the metal material.
5C) is smaller than the amount of protrusion Δt ₂ from the surface of the gasket body.

The metal spacers 9 and 10 have circular recesses (recesses 9b for the metal spacer 9, 9
c) is formed. By spot welding in this recess, the metal spacers 9, 10
is attached to the gasket body 4. As a result, the metal spacer 9, which is made by spot welding,
10, a crater that is generated at the joint portion of the metal spacers 9, 10 with the gasket body 4 is formed in a recess, and the contact surfaces 9a, 10a, which are the surfaces of the metal spacers 9, 10, Deterioration of flatness is prevented and a smooth surface is maintained.

With the above structure, when the intake manifold gasket 1 is interposed between the cylinder head and the intake manifold and is tightened to a predetermined value with the tightening bolt, the intake manifold gasket 1 receives a compressive load. The sealing members 5A, 5B, and 5C, which are softer than the metal spacers 9 and 10, are compressively deformed up to the thickness (protrusion amount Δt ₁ ) of the metal spacers 9 and 10, but cannot be compressed and deformed further. do not have. That is, most of the compressive load due to the tightening of the intake manifold gasket 1 is received by the gasket body 4 via the metal spacers 9 and 10, and an excessive compressive load will not act on the seal members 5A, 5B, and 5C. do not have. Therefore, excessive deformation due to the tightening force of the intake manifold gasket 1 does not occur in the seal members 5A, 5B, and 5C.
At the same time, the contact surface pressure between the cylinder head or intake manifold and the seal members 5A, 5B, 5C is prevented from decreasing, and airtightness at this contact surface is maintained.

In addition, since the above-mentioned intake manifold gasket 1 does not have a core material, it can be
96346), when the core material is installed between the cylinder head and the intake manifold, due to the difference in thickness and compression force between the top and bottom of the core material,
This eliminates the problem of torsion or other forces acting on the joint (root) of the seal member with the gasket body.

Next, when the engine is operated in this state, the intake manifold gasket 1 will be damaged due to thermal expansion, deflection, vibration, etc. of the cylinder head and intake manifold.
The compressive load received by the gasket changes, but most of the changing load is received by the gasket body 4 via the metal spacers 9 and 10. Therefore, the seal members 5A, 5B, and 5C do not deteriorate due to changes in compressive load, and as a result, the seal members 5A, 5B, and 5C do not deteriorate due to changes in compressive load.
Deterioration of airtightness and loosening of tightening bolts due to deterioration of A, 5B, and 5C are prevented.

The above embodiment describes the intake manifold gasket interposed between the cylinder head and the intake manifold, but the intake manifold gasket interposed between the intake manifold and the surge tank (expansion chamber) It can also be applied to

(Effects of the invention) As described above, in the present invention, the gasket body is held between the metal spacers, which protrude less from the surface of the gasket body than the sealing member, so that the sealing member can be held by the metal spacers. It is possible to prevent a decrease in sealing performance due to sagging. In addition, since the metal spacer is attached to the gasket body by spot welding in the recess formed in the contact surface that contacts the intake passage component, when joining the metal spacer by spot welding, the surface of the metal spacer It is possible to prevent the flatness of the metal spacer from decreasing due to craters that occur in the spacer.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a plan view of an intake manifold gasket, FIG. 2 is an enlarged sectional view taken along the line -- in FIG. 1, and FIG. 3 is a front view of a V-type engine. 1...Intake manifold gasket, 2A, 2
B, 2C, 3A, 3B, 3C...opening, 4...
Gasket body, 5A, 5B, 5C... Seal member, 9, 10... Metal spacer, 9a, 10a
...Abutment surface, 9b, 9c... recess.

Claims (1)

[Claim for Utility Model Registration] An intake manifold gas consisting of a gasket body in which an opening serving as an intake passage is formed, and an annular sealing member that is softer than the gasket body and provided on the inner peripheral surface of the opening. In the gasket, the gasket main body is held between metal spacers that protrude less than the sealing member, and the metal spacer has a recess formed in the contact surface that contacts the intake passage constituent member, and the gasket body in the recess is The structure of an intake manifold gasket is characterized in that a metal spacer is attached to the gasket body by spot welding.