JP2890346B2 - Gasket for exhaust manifold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasket for an exhaust manifold of an internal combustion engine, and more particularly to a gasket for an exhaust manifold of a multi-cylinder internal combustion engine.

[0002]

2. Description of the Related Art As shown in FIG. 4, an exhaust manifold of a multi-cylinder internal combustion engine is composed of an ordinary exhaust manifold 1 having an inner branch pipe 3-1 and an outer branch pipe 3-2 branched from a manifold body 2.
(If it is not necessary to distinguish each branch pipe, it is simply indicated as 3). The inner exhaust port 5-1 and the outer exhaust port 5-2 of the internal combustion engine 4 (if it is not necessary to distinguish each exhaust port, simply 5).

[0003] Since high-temperature exhaust gas flows through the exhaust manifold 1, a gasket for sealing between the exhaust manifold 1 and the exhaust port 5 is usually a gasket for an exhaust manifold (hereinafter referred to as a gasket) using a thin metal plate having high heat resistance. It is known that a gasket 6 is used.

[0004]

However, the shape of the exhaust manifold, particularly the shape of the exhaust manifold for an internal combustion engine mounted on an automobile or other vehicle cannot be determined independently, and is attached to the vehicle body structure and the engine compartment. Subject to restrictions such as the placement of other equipment. Therefore, as shown in FIG. 4, the deformation when the exhaust manifold 1 is thermally expanded by contact with the high-temperature exhaust gas is generally caused in such a direction that the outer branch pipe 3-2 is separated from the internal combustion engine 4 more than the inner branch pipe 3-1. Manifold body 2
Receives the warping deformation force. Therefore, there is a problem that the sealing performance of the gasket 6 is reduced.

The present invention has been made in view of the above-mentioned problem, and provides a gasket for an exhaust manifold in which the sealing performance does not deteriorate even when the exhaust manifold is subjected to an outwardly deformed force by high-temperature exhaust gas. It is intended to be.

[0006]

Configuration of an exhaust manifold gasket of the present invention for achieving the above object, there is provided a means for solving] is formed as the branch pipes of the exhaust manifold reaches the exhaust ports in the launch like a branch root source and a bolt for fixing the branch pipe to the internal combustion engine, provided for each exhaust port, the exhaust port
Are arranged substantially linearly in the cylinder arrangement direction of the internal combustion engine,
The branch pipes arranged on both outer sides of the arranged exhaust ports
Is deformed by the exhaust heat and warps away from the internal combustion engine.
And a metal gasket for a multi-cylinder line type internal combustion engine that receives stronger than the center side, before the bead plate of the metal gasket
Opening the exhaust hole matching the respective serial exhaust ports of
And, the cross-sectional shape of the bead to be formed around the exhaust Kiana, before
The serial outer trapezoidal, the center side is obtained by forming each arcuate.

[0007] A plurality of bead plates can be used.
For example, the beads formed on the two bead plates can be formed at positions that match each other and in such a manner that the projecting directions of the beads are opposite to each other. When an exhaust hole is also formed between the outer side and the center side, such as in a six-cylinder in-line type internal combustion engine, the bead shape formed in the intermediate exhaust hole has a bead width wider than the center side. The cross-sectional shape may be arched, or the bead width may be narrower than the outside, and the cross-sectional shape may be trapezoidal.

[0008] Further, in the gasket, a surface plate can be laminated on the outside of the bead plate. In addition, one surface plate is folded back to the opposite side so that the high temperature exhaust gas does not come into direct contact with the bead portion, and the end portion is covered. Means can be used as appropriate. The bead is compressed with a smaller tightening force as the bead width is wider and the trapezoidal cross-sectional shape is smaller than the arch shape. In contrast,
When bolting the exhaust manifold to the internal combustion engine, the bolt tightening force is determined by using a torque wrench, etc.
The operation is performed so as to be constant for all bolts.

As the exhaust manifold is warped, the bolt force concentrates on the inside, so that the exhaust manifold is likely to be warped outward even in the initial tightening state, and the exhaust manifold warps away from the exhaust port as described above by use. . On the other hand, the gasket of the present invention is provided with an arched bead on the inside and a trapezoidal bead on the outside. A margin is obtained in the tightening force, the deformation of the exhaust manifold is suppressed, and a reliable and stable sealing performance can be obtained.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention; The exhaust manifold gasket 6 (hereinafter simply referred to as a gasket) 6 of the present embodiment shown in FIGS. 1 to 3 is for a four-cylinder row internal combustion engine, and has an inner exhaust hole 7-1 and an outer exhaust hole 7-2 ( Two bolt holes 8 are provided for each of the exhaust holes 7 for tightening the bolt holes 8 when there is no particular need to distinguish them.

The mounting position of the bolt hole 8 is as follows.
As shown in FIG. 1, although not uniform for each exhaust hole 7, two of each are arranged substantially symmetrically with respect to the center of the exhaust hole 7. The choice of this arrangement depends on the position of the bolts attached to the internal combustion engine (not shown) used. The inner exhaust hole 7-1 is shown in FIG.
As shown in FIG. 3, a trapezoidal bead 12 having a width L and a height h is formed on each of the bead plates 9 and 10 so as to protrude in the opposite direction, and as shown in FIG. Similarly to the above, arched beads 11 having a width L and a height h were formed on the two bead plates 9 and 10 so as to protrude in opposite directions, and a surface plate 13 was laminated on the outside of these.

The gasket 6 of the present embodiment formed as described above is interposed between the internal combustion engine and the exhaust manifold, and bolts (all of which are shown in FIGS. Was tightened. The trapezoidal bead 12 has a smaller repulsive resilience to compression than the arched bead 11, and is easily compressed.Therefore, the reaction of the trapezoidal bead 12 to the bolt is smaller than the reaction of the arched bead 11 to the bolt. The force with which the bolt for tightening the outer branch pipe 3-2 can oppose the deformation force of the exhaust manifold is greater than the force with which the bolt for tightening the inner branch pipe 3-1 can oppose the deformation force. Therefore, the deformation of the exhaust manifold is suppressed, and the gasket for the exhaust manifold of the present embodiment can exhibit a reliable and stable sealing performance.

[0013]

As described above in detail, the exhaust manifold gasket of the present invention has a trapezoidal bead for the outer exhaust hole having a large deformation force in the direction away from the exhaust port, and an inner bead having the small deformation force. Since the bead of the exhaust hole is formed in an arc shape, the tightening force of the exhaust port bolt can be afforded with respect to the deformation force of all the branch pipes, the deformation of the exhaust manifold is suppressed, and a reliable and stable sealing performance is achieved. Can be demonstrated.

[Brief description of the drawings]

FIG. 1 is a plan view of a gasket for an exhaust manifold according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged sectional view taken along line III-III of FIG. 1;

FIG. 4 is a plan view in which a deformation amount is exaggerated and a part is cut away to explain a problem of the manifold of the conventional exhaust manifold.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Exhaust manifold 2 Manifold main body 3-1 Inner branch pipe 3-2 Outer branch pipe 4 Internal combustion engine 5-1 Inner exhaust port 5-2 Outer exhaust port 6 Gasket (gasket for exhaust manifold) 7 Exhaust hole 7-1 Inner exhaust hole 7-2 Outside exhaust hole 8 Bolt hole 9 Bead plate 10 Bead plate 11 Arched bead 12 Trapezoidal bead 13 Surface plate L Width h Height

Claims (2)

(57) [Claims] 1. A formed as branch pipe of the exhaust manifold reaches the exhaust ports in the launch like a branch root source bolts for fixing the branch pipe to the internal combustion engine, provided for each exhaust port, the exhaust Port in the direction of cylinder arrangement of the internal combustion engine.
The branch pipes arranged in a line shape and arranged on both outer sides of the arranged exhaust ports are separated from the internal combustion engine by exhaust heat.
The deformation force warped direction, a metal gasket for a multi-cylinder line type internal combustion engine that receives stronger than the center side, said metal gasket
Align each of the above exhaust ports with the bead plate of
That an exhaust hole is opened, the cross-sectional shape of the bead to be formed around the exhaust Kiana, said outer trapezoidal, exhaust manifold gasket that the center side is formed respectively on the arcuate. 2. The gasket for an exhaust manifold according to claim 1, wherein the beads formed on the two bead plates are formed at positions aligned with each other, and the projection directions of the beads are opposite to each other.