JPH0534385Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an improvement of a seal structure using a liquid gasket in an oil pan or the like of an automobile engine.

BACKGROUND ART Liquid gaskets have conventionally been used, for example, as gaskets for engine oil pans.
This is made of uncured synthetic rubber, and if it is applied to the flange of the oil pan and joined to the cylinder block, it will naturally harden and seal between the two (for example, Utility Model Application No. 60-61561). Public bulletin).

12 and 13 show an example of an oil pan seal structure using a liquid gasket as described above, in which a front cover 2 is attached to the front end of a cylinder block 1, and the lower peripheral edge of both A continuous first sealing surface 3 is formed on the flange of the oil pan 4, and a second sealing surface 5 is formed on the flange of the oil pan 4. are connected through. Note that the front cover gasket 7 between the cylinder block 1 and the front cover 2 is
In some cases, a liquid gasket is used, and in some cases, a pre-formed regular gasket is used.
The figure shows the case where a liquid gasket is used.

Problems to be Solved by the Invention However, in the conventional seal structure using the liquid gasket 6 as described above, the material of the cylinder block 1 is cast iron, and the material of the front cover 2 has a coefficient of thermal expansion higher than that of cast iron. When using a large aluminum alloy, the front cover 2 expands downward significantly when the temperature rises, which is in the state shown in FIG. 13 at room temperature, causing the first sealing surface 3 to expand as shown in FIG. There is a risk that the step 1 will be created, and the liquid gasket 6 will not be able to follow it and will peel off, creating a gap 8. Particularly, when a liquid gasket is used as the front cover gasket 7 between the cylinder block 1 and the front cover 2 as shown in the figure, the front cover gasket 7 is constructed to be very thin, that is, the front cover gasket 7 is formed between the cylinder block 1 and the front cover 2. Since the distance between the front cover 2 and the front cover 2 becomes smaller, the influence of the step 1 due to thermal expansion appears even more, and the liquid gasket 6 between the oil pan 4 and the oil pan 4 is likely to separate. Further, even if the two parts are made of the same material, a similar problem occurs when the ambient temperatures around the two parts are different.

Means for solving the problems In order to solve the above problems, this invention
In a seal structure in which one sealing surface is formed to form a continuous surface across two parts that are joined to each other via a liquid gasket, and this sealing surface is joined to another part via the liquid gasket, It is characterized in that a recess is formed at the edge of at least one of the parts along the line where the boundary surface of the two parts intersects with the sealing surface, and an elastic body or a liquid gasket is inserted into the recess.

Effect Even if the two parts are slightly misaligned due to the difference in thermal expansion,
This deviation is absorbed by the elastic body or liquid gasket in the recess located at the boundary between the two, and no extreme step difference occurs. Therefore, separation of the liquid gasket is prevented.

Embodiment FIG. 1 is a diagram showing the main parts of the seal structure according to this invention, and similar to FIG. 13 described above, FIG.
An enlarged view of part A in the figure is shown.

In the figure, 1 is a cylinder block made of, for example, cast iron, 2 is a front cover made of, for example, an aluminum alloy, and 4 is an oil pan connected to these through a liquid gasket 6, respectively. The cylinder block 1 and the front cover 2 are joined via a liquid gasket shown as a front cover gasket 7. In this embodiment, a chamfer of an appropriate size is provided at the lower edge of the front cover 2. As a result, a recess 11 is formed at a position where the first sealing surface 3 intersects the boundary surface of two parts made of different materials, that is, the cylinder block 1 and the front cover 2. A liquid gasket 6a is inserted into this recess 11 in the same way as between the other sealing surfaces 3 and 5.

In the above configuration, when the front cover 2 thermally expands more than the cylinder block 1 due to a rise in temperature, the lower surface of the front cover 2 shifts downward relative to the lower surface of the cylinder block 1, as shown in FIG. However, there is a recess 1 on the boundary between the two.
1 is provided in the cylinder block 1.
Since the corner 12 of the front cover 2 and the corner 13 of the front cover 2 are separated to some extent, an extreme step does not occur, and the liquid gasket 6a inserted into the recess 11 is
The deviation between the two is absorbed by Therefore, separation of the liquid gasket 6 from the lower surface of the cylinder block 1 can be prevented.

Next, in the embodiment shown in FIG.
A groove with a square cross section is provided on the lower edge of the recess 1.
1 was formed.

4 and 5 show an embodiment in which the edges of the lower ends of the front cover 2 and the cylinder block 1 are chamfered or grooved to form a recess 11 on the boundary between them.
As shown in Figs. 6 and 7, the lower end is R
The shape may be such that a recess 11 is formed.

The chamfers and grooves for forming the recess 11 may be formed by molding when the front cover 2 and cylinder block 1 are cast, or may be formed by secondary processing after casting.

Next, the embodiments shown in FIGS. 8 to 11 are as follows:
An elastic body 14 such as rubber is inserted into each of the recesses 11 formed as described above. in this case,
The lower surface of the elastic body 14 is configured to be continuous with the lower surface of the front cover 2 and the lower surface of the cylinder block 1 to form a first sealing surface 3, and the liquid gasket 6 includes the elastic body 14 portion. It is coated with a substantially uniform thickness.

Even in the structure in which the elastic body 14 is inserted in this manner, it is possible to absorb the misalignment between the cylinder block 1 and the front cover 2, and it is possible to reliably prevent the liquid gasket 6 from peeling off.

Effects of the invention As is clear from the above explanation, according to the seal structure according to the invention, when sealing a seal surface formed over two parts with a liquid gasket, a difference in level due to the difference in thermal expansion between the two parts can be removed. It is possible to alleviate this and prevent the liquid gasket from peeling off. Therefore, reliable sealing performance can be maintained over a long period of time in engine oil pans and the like that are exposed to high temperatures.

[Brief explanation of the drawing]

Fig. 1 is a partially enlarged view showing an embodiment of this invention, Fig. 2 is a partially enlarged view showing its state at high temperature, Figs. 3, 4, 5, 6, and 7. 8, 9, 10, and 11 are partially enlarged views showing examples in which the shape of the concave portion is changed, respectively.
The figures are partially enlarged views showing embodiments in which elastic bodies are inserted into the recesses, Fig. 12 is a side view of an engine using a conventional seal structure, and Fig. 13 is a partially enlarged view of part A in Fig. 12. , FIG. 14 is a partially enlarged view showing the state at high temperature. 1... Cylinder block, 2... Front cover, 3... First seal surface, 4... Oil pan, 5
...Second sealing surface, 6...Liquid gasket, 11
...Concavity, 14...Elastic body.

Claims (1)

[Scope of utility model registration request] In a seal structure in which one sealing surface is formed to form a continuous surface across two parts that are joined to each other via a liquid gasket, and this sealing surface is joined to another part via the liquid gasket, A seal structure characterized in that a recess is formed at the edge of at least one of the parts along a line where the boundary surface of the two parts intersects with the sealing surface, and an elastic body or a liquid gasket is inserted into the recess.