JPH051735Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a gasket interposed between an exhaust manifold and a cylinder head of an internal combustion engine.

[Conventional technology]

Gaskets for exhaust manifolds of internal combustion engines are required to have exhaust gas sealing properties and heat insulation properties from the manifold to the cylinder head.

Conventional gaskets include metal laminated gaskets with beaded portions and gaskets provided with a heat insulating material such as steel vest.

For example, the metal laminated type gasket is
-26862 (already proposed by the applicant). As shown in FIG.
No. 0 has thin stainless steel plates 102 laminated, some of which are provided with beads (protrusions) 102a, and elastic force is imparted by the beads 102a. The elastic force of this bead 102a provides good sealing performance, but poor heat insulation performance.

Further, as shown in FIG. 8, a heat insulating material 202 such as a steel vest is attached to a thin metal plate 202 provided with claws 204a.
The gasket 200 held between the
There is a problem of poor sealing performance due to poor followability to thermal strain acting on the manifold.

[Problem that the invention attempts to solve]

On the other hand, as shown in FIG. 9, a heat insulating material 302 is arranged on the exhaust manifold 306 side,
The present applicant has proposed a gasket 300 in which a thin metal plate 304 having a bead portion 304a is disposed on the head 308 side (Utility Application No. 62-2931; unknown).

However, since this gasket 300 has a heat insulating material 302 on the exhaust manifold side, although it has a heat insulating effect, it is inferior in followability. If the bolts are tightened strongly and the gasket 300 is compressed in order to improve the sealing performance, the bead portion 3
When 04a bends, the insulation material 3 made of asbestos etc.
There was a problem that damaged the 02.

An object of the present invention is to provide a gasket that satisfies both heat insulation and sealing properties by using a gasket that includes a heat insulating material and a thin metal plate on which beads are formed, and that does not cause damage to the heat insulating material.

[Means for solving the problem] Therefore, in the exhaust manifold gasket of the present invention, the heat insulating material is interposed between the main plates with shims between the beads of the main plate having elastic force, thereby reducing the heat insulating material. Characterized by preventing damage.

Specifically, the configuration of the present invention is as follows.
Incidentally, the reference numerals in FIG. 1 are given for reference.

The present invention is a gasket 10 interposed between an exhaust manifold and a cylinder head of an internal combustion engine.

This gasket 10 is sandwiched between at least two main plates 16 and 18 which are arranged at least on the exhaust manifold side and the cylinder head side and have bead portions 16b and 18b and have elastic force, and the bead portion between these main plates 16 and 18. Sim 2
0 and the bead portion 16 between these main plates 16 and 18
This is for an exhaust manifold consisting of a low thermal conductive intervening body 22 which is sandwiched between portions other than b and 18b.

[Effect]

According to the above-mentioned exhaust manifold gasket 10 of the present invention, the main plates 16 and 18 having bead portions 16b and 18b and having elastic force are arranged at least on the exhaust manifold side and the cylinder head side, respectively, so that the exhaust manifold gasket 10 and the cylinder head It has high followability against thermal distortion, etc., and has good sealing performance. Further, since the intervening body 22 having low thermal conductivity is sandwiched between the main plates 16 and 18, the heat insulating effect of the intervening body 22 makes it difficult for heat from the exhaust manifold to be transmitted to the cylinder head. Also, when tightening between the main plates 16 and 18, the bead portions 16b and 18b are bent and the main plates 16 and 18 are bent.
8 becomes narrower, but the bead portions 16b, 18b
Since the shim is sandwiched between the main plates 16, 1
8 is never smaller than the width of the shim 20. Therefore, the thickness of the intervening body 22 is determined by the thickness of the shim 2.
If the thickness is kept below zero, the intervening body 22 will not be damaged. Further, the thickness of the intervening body 22 may exceed the thickness of the shim 20 as long as the intervening body 22 is not damaged and the heat insulating effect is not reduced.

〔Example〕

Next, an embodiment of the exhaust manifold gasket according to the present invention will be described with reference to FIGS. 1 to 6.

Fig. 1a is a sectional view taken along the line - in Fig. 4 and shows the state before fastening, Fig. 1b is the same side view as Fig. 1a showing the state after fastening, and Fig. 2 a
is a cross-sectional view taken along the line - in FIG. 4, showing the state before fastening; FIG. 2b is the same side view as FIG. 2a, showing the state after fastening; FIG. Diagram a
4 is a view seen from the direction perpendicular to the gasket surface, FIG. 5 is a view showing another aspect, and FIG. 5a is a drawing corresponding to FIG. 1a. , FIG. 5b is a drawing corresponding to FIG. 1b,
6 is a drawing corresponding to FIG. 3.

As shown in FIG. 4, the exhaust manifold gasket 10 connects the exhaust port to the sealing portions 10a to 10d and their connecting portions 10e to g.
Consisting of Bolt holes 12a-d and 14a-d are provided around the seal portions 10a-d, respectively. Note that FIG. 4 is a view seen from the exhaust manifold side, and in this embodiment, a gasket for a four-cylinder engine is used.

As shown in FIG. 1, the gasket 10 includes a thin metal plate 1 serving as a main plate on the exhaust manifold side.
6 and thin metal plate 1 as the main plate on the cylinder head side.
A shim 20 is held between the shims 8 and 8. The shim 20 has an annular shape along the seal portions 10a to 10d of the exhaust port, and is held between beads 16b and 18b formed on the thin metal plates 16 and 18. And the exhaust port,
Seal parts 10a-d, bolt holes 12a-d, 1
An intervening body 22 is inserted between the metal thin plates 16 and 18 other than 4a to 4d. Metal thin plates 16, 18
is made of stainless steel with a thickness of 0.25 to 0.3 mm, and beads 16b to 18b with a height of 0.15 to 0.3 mm are formed. The shim 20 is made of a highly rigid and heat resistant material with a thickness of 0.7 to 1.0 mm. Intermediate body 2
2 is made of a woven inorganic fiber fabric with low conductivity such as woven glass fiber or vermiculite, hardened with a binder (NBR, SBR), and has an average thickness of 0.8~ 1.1mm and shim 2
It is slightly larger than 0. Note that organic fibers such as aramid fibers may be used instead of inorganic fibers. The intervening body 22 is placed between the thin metal plates 16 and 18 together with the shim 20 by cutting a woven fabric into a predetermined shape. Then, the bolt holes 12 of the thin metal plates 16 and 18 are connected to the exhaust manifold (not shown).
Connect the bolts (not shown) inserted through bolts a to d and 14a to d to the cylinder head (not shown).
By fastening it to the metal thin plates 16 and 18, it is sandwiched between the thin metal plates 16 and 18.

Next, regarding the function of the gasket 10 mentioned above,
explain.

In the gasket 10, when the bolt is fastened in the state shown in FIG. The elastic force of beads 16b and 18b acts on the contact surface between the exhaust manifold and the cylinder head. Since the shim 20 is made of a material with high rigidity and high heat resistance, the beads 16b and 18b are
Even when subjected to thermal cycles and vibrations due to engine operation, the sealing performance hardly deteriorates. Furthermore, since the intervening body 22 is made of a material having low thermal conductivity, it blocks heat from the exhaust manifold from being transmitted to the cylinder head. Furthermore, when the bolts are tightened, the beads 16b and 18b are bent, the distance between the thin metal plates 16 and 18 is narrowed, and the intervening body 22 is compressed, but since the intervening body 22 is only slightly thicker than the shim 20. , the intervening body 22 is not damaged and the heat insulation performance of the intervening body 22 is not deteriorated.

In this embodiment, an inorganic fiber woven fabric is used as the intervening body 22, but a mesh-filled steel plate 24 may also be used as shown in FIG. Since this mesh steel plate has the air layer 24a, it has high heat insulation properties. However, since the thin metal plates 16 and 18 have high rigidity and do not shrink due to compression even if they are bent, it is necessary to make the thickness equal to or less than the thickness of the shim 22.

Moreover, a wire mesh sheet may be used in place of the mesh rigid plate 24. This wire mesh sheet also has many air spaces, so it has high heat insulation properties. Since the wire mesh sheet has elasticity, it can be bent even if the space between the thin metal plates 16 and 18 becomes narrow. Therefore,
It can be made thicker than the shim 22, increasing the strength of the gasket itself.

As mentioned above, the gasket of this example has both heat insulation and sealing properties, so it cuts off heat from the exhaust manifold without causing gas leaks, thereby lowering the temperature of the cylinder head. can increase the durability of Furthermore, since the temperature distribution of the exhaust manifold becomes uniform, thermal distortion is less likely to occur in the exhaust manifold, increasing the durability of the exhaust manifold.

Although a specific embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and includes various embodiments within the scope of the claims for utility model registration. It is.

[Effect of idea]

From the above, according to the exhaust manifold gasket of the present invention, by interposing a heat insulating material between the main plates with shims between the beads of the main plate having elastic force, both heat insulation properties and sealing properties are satisfied. At the same time, damage to the insulation material can be prevented.

Further, since the intervening body is surrounded by the main plate and the shim, there is an advantage that the intervening body is unlikely to protrude outside between the main plates.

[Brief explanation of the drawing]

1 to 6 are drawings for explaining an embodiment of the exhaust manifold gasket according to the present invention, and FIG. 1a is a sectional view taken along the line - in FIG. Figure 1b is the same diagram as Figure 1a, showing the state after fastening, and Figure 2a is a sectional view taken along the line - in Figure 4, showing the state before fastening. , FIG. 2b is the same drawing as FIG. 2a showing the state after fastening,
Figure 3 is a sectional view taken in the direction of arrows in Figure 1a;
The figure is a view perpendicular to the gasket surface.
FIG. 5 is a diagram showing another aspect, and FIG. 5a is a diagram showing another aspect.
A drawing corresponding to Fig. 1a, Fig. 5b is a drawing corresponding to Fig. 1b.
and FIG. 6 is a drawing corresponding to FIG. 3. 7 to 9 are drawings for explaining conventional examples. FIG. 7 is a sectional view of a gasket made of a thin metal plate provided with beads, and FIG. 8 is a sectional view of a gasket made of a heat insulating material. FIG. 9 is a cross-sectional view of a gasket having a metal sheet with beads on one side and a heat insulating material on the other side. 10... Gasket, 16, 18... Main plate (thin metal plate), 16b, 18b... Bead portion, 20...
...Shim, 22...Intervening body (inorganic fiber woven fabric).

Claims (1)

[Claims for Utility Model Registration] A gasket interposed between an exhaust manifold and a cylinder head of an internal combustion engine, the gasket having at least an elastic bead portion disposed on at least the exhaust manifold side and the cylinder head side respectively. For an exhaust manifold comprising two main plates, a shim held between the main plates at a bead part, and a low thermal conductivity intervening body held between the main plates at a location other than the bead part. Gasket.