JPS6133204Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to a synthetic resin oil pan for an engine.

Conventional technology Generally speaking, the oil pan, which is a part of the engine, has
In order to reduce the weight of the engine and reduce engine noise, it is made of synthetic resin such as plastic (Japanese Utility Model Publication No. 73509/1983). In this synthetic resin oil pan, if an oil drain hole is provided to drain the oil, if the oil pan is threaded to form the oil drain hole, it will be screwed into the oil drain hole when changing the oil. Since the annular bolt must be removed from the oil drain hole, frequent oil changes may cause the threaded part of the oil drain hole to wear out, resulting in oil leaking from the gap between the oil drain hole and the annular bolt. There was a problem with the lack of long-term reliability.

Therefore, in conventional synthetic resin oil pans, a metal insert is provided with a threaded oil drain hole in the center of the oil pan. A drain is formed by threading a drain bolt onto the insert and further interposing a sealing member between the head of the drain bolt and the outer surface of the insert.

Problems that the invention aims to solve However, with this type of drain structure, when the temperature of the lubricating oil increases during engine operation, the oil pan and insert thermally expand. A gap was created between the inner circumferential surface of the fitting hole of the pan and the outer circumferential surface of the insert, and a problem also occurred in that lubricating oil leaked from this gap.

This idea was devised in view of the conventional problems mentioned above, and was developed to create a synthetic resin engine that does not leak even when the oil is changed frequently or the temperature of the lubricating oil rises. The purpose is to provide oil pans.

Means for Solving the Problems Therefore, the synthetic resin oil pan for an engine according to this invention has an annular protrusion projecting outward from the synthetic resin oil pan body, the center of which serves as an oil drain hole. A circumferential protrusion is formed on the lower end of the outer periphery of the protrusion, and a metal annular bolt is fixed between the circumferential protrusion on the outer circumference of the protrusion and the oil pan body. A cap nut is screwed onto the bolt, and a sealing member is interposed between the cap nut and the circumferential protrusion.

Function In this invention, when the cap nut is screwed onto the metal annular bolt, the circumferential protrusion of the protrusion and the sealing member are pinched between them, and the circumferential protrusion and the cap nut are pressed together. is sealed, and even if a gap occurs between the annular bolt and the protruding part due to the difference in thermal expansion coefficient, oil leakage will not occur, and the metal annular bolt is fixed to the synthetic resin oil pan body side. However, since a cap nut is screwed into this, there is little wear on the threaded part even if the oil is changed frequently, and a strong threaded state is maintained for a long time, thereby ensuring the prevention of oil leaks mentioned above. be done.

Example An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show a synthetic resin oil pan for an engine according to an embodiment of the present invention. In the figure, 1 is an engine, and the engine 1 is composed of an engine body 2 and an oil pan 9 attached to the lower side of the engine body 2 and storing lubricating oil 3.

In this oil pan 9, reference numeral 4 denotes an oil pan body made of synthetic resin, and an annular protrusion 5 that protrudes outward, that is, downward, is integrated with the oil pan body 4 on the bottom surface of the oil pan body 4. is formed. The center of the protrusion 5 is an oil drain hole 5a for discharging the lubricating oil 3, and the outer peripheral surface of the protrusion 5 has a circumferential protrusion 5b at the lower end and an outer surface 4a of the oil pan body 4. A metal annular bolt 6 is fixed between them.

A metal cap nut 7 is screwed onto the annular bolt 6, and a seal ring 8 is disposed between the upper end surface 7a of the cap nut 7 and the outer surface 4a of the oil pan main body 4.
A is interposed therebetween, and a seal plate 8b is interposed between the inner surface 7b of the cap nut 7 and the lower surface 5c of the protrusion 5.

Next, the effects will be explained.

In this oil pan, when changing the oil, first loosen the cap nut 7 from the annular bolt 6, drain the old lubricating oil 3 stored at the bottom of the oil pan 9 from the oil drain hole 5a of the protrusion 5, After most of the old lubricating oil 3 has been drained, the cap nut 7 is screwed onto the annular bolt 6 again to completely close the oil drain hole 5a and new lubricating oil is supplied.

In the oil pan of this embodiment, the seal ring 8a
Since the seal plate 8b directly seals between the cap nut 7 and the oil pan main body 4 and between the cap nut 7 and the circumferential protrusion 5b of the protrusion 5, the lubricating oil 3 is removed by engine operation. The temperature increases,
Due to the difference in thermal expansion coefficient, the annular bolt 6 and the protrusion 5
Even if a gap is formed between the two, oil leakage will not occur. In particular, the cap nut 7 and the circumferential protrusion 5
Regarding the sealing performance between cap nuts 7 and b, by screwing the cap nut 7 onto the annular bolt 6, the circumferential protrusion 5b and the sealing plate 8b are compressed between them, thereby sealing between the cap nut 7 and the circumferential protrusion 5b. Because of this, high sealing surface pressure can be obtained and good sealing performance can be ensured. Moreover, a metal annular bolt 6 and a metal cap nut 7
Because they are screwed together, the threaded parts of the bolts 6 and 7 are unlikely to wear out even if the oil is changed frequently, and the strong threaded state of the bolt 6 and nut 7 is maintained for a long time, so the seal ring 8a and The sealing performance of the seal plate 8b is maintained well over a long period of time.

In the above embodiment, a seal member is provided both between the cap nut and the oil pan body and between the cap nut and the circumferential projection of the protrusion, but the seal member is not necessarily provided between the cap nut and the oil pan body. There is no need to provide Furthermore, the cap nut is not necessarily limited to being made of metal because it can be replaced at any time even if it wears out.

Effects of the invention As described above, according to the invention, an annular protrusion whose center is an oil drain hole is integrally formed on the synthetic resin oil pan body, and the outer circumference of this protrusion is Along with forming a circumferential protrusion on the lower end,
An annular bolt is fixed to the outer circumferential surface of the protrusion, a cap nut is screwed onto the annular bolt, and a sealing member is interposed between the cap nut and the circumferential protrusion of the protrusion so that the cap nut and the cap nut are connected to each other. Since the protrusion is directly sealed, good sealing performance is maintained over a long period of time, and oil leakage does not occur.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of an engine having a synthetic resin oil pan according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the main part of FIG. 1. 1...Engine, 3...Lubrication oil pan, 4...
... Oil pan body, 5 ... Projection, 5a ... Oil drain hole, 5b ... Circumferential projection, 6 ... Annular bolt, 7 ...
...Bag nut, 8b...Seal plate (sealing member),
9...Oil pan.

Claims (1)

[Scope of Claim for Utility Model Registration] An oil pan body made of synthetic resin that is installed at the bottom of the engine and stores lubricating oil; is an oil drain hole for discharging lubricating oil, and the lower end of the outer periphery has an annular protrusion formed with an annular circumferential protrusion that protrudes in the radial direction, and the outer periphery of the protrusion. A metal annular bolt fixed between the circumferential protrusion of the surface and the oil pan body, a cap nut screwed onto the annular bolt, and a cap nut interposed between the cap nut and the circumferential protrusion. A synthetic resin oil pan for an engine, characterized in that it is equipped with a seal member.