JPS6111565Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for preventing O-rings from falling off.

Conventionally, a cover member is installed with the sealing surface in which an O-ring insertion groove is vertically formed facing downward or to the side. For example, in an engine oil pump, the pump casing is formed on the cylinder body and is covered with a cover. In products with a sealing part, the width of the groove is generally larger than the width of the O-ring in order to provide a crushing allowance.
There was a problem with the O-ring falling off during assembly.

A method of preventing the O-ring from falling off has also been adopted, in which the O-ring is fixed in advance in the groove with an adhesive, but this method has the drawbacks of increasing the cost and the number of work steps.

A sealing device to solve the above-mentioned problems and shortcomings is disclosed in Japanese Utility Model Application Publication No. 52-127124, but in this device, a plurality of protrusions are provided protruding from the side wall of the groove for inserting the sealing member. In doing so, the protrusion is provided completely unrelated to ensuring a boss meat portion for preventing a lack of thickness around the connection bolt insertion hole 8 formed in the flange 3 of the carburetor component, so the flange 3 There is a problem that the boss is made large in order to secure the boss flesh portion.

This is a requirement that must be carefully considered in the design of sealing devices, especially in components where compactness is sought, such as engine components.

This invention was devised in view of the above-mentioned shortcomings and inconveniences, and it makes it possible to make the cover member with the O-ring insertion groove more compact, prevent the O-ring from falling off, and provide an O-ring that is extremely easy to design and manufacture. The purpose is to provide a fall prevention device for
The gist thereof lies in an O-ring fall prevention device in which a boss portion of a bolt insertion hole of a cover member having an O-ring insertion groove is made to protrude into the O-ring insertion groove.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

1 and 2 show an embodiment of an oil pump for an engine. Reference numeral 10 indicates a pulley for driving the oil pump, 20 indicates a pump cover, and the drive shaft 11 fixed to the pulley 10 is connected to the pump cover 2.
The pump casing 30 is formed by a cylinder body 3 that penetrates through the cylinder body 3 and accommodates the outer row 32.
It extends inward and is fixed to the inner rotor 31 with screws 35 or the like. Also, 21 is the cover 20
33 is a side surface of the cylinder body opposing this, and 22 is a pin for positioning.

As particularly shown in FIG. 2, an O-ring insertion groove 23 is formed in the mating surface 21 of the pump cover 20 at a position relative to the outer periphery of the outer rotor 32, and the cover 20 is further inserted into the cylinder body at the outer periphery thereof. A plurality of so-called bolt insertion holes 25 are formed through which bolts for attaching to the main body 3 are inserted.

Of the boss portions 26 set around the bolt insertion hole 25 in consideration of preventing lack of thickness, the O-ring 40 is inserted into the boss portion 26a between the bolt insertion hole 25 and the groove 23. It extends to the extent that it can be pressed.

The width t2 of the groove in the overhanging portion 27 of the boss flesh portion 26a is set to be smaller than the width t1 of other groove portions and slightly smaller than the free width to of the O-ring 40, so that the O-ring 40 can be supported elastically. It's becoming like that.

As a result, when the O-ring 40 is inserted into the groove 23, the sides of the O-ring 40 are elastically pressed by the protruding portion 27 of the boss flesh portion 26a, so that the O-ring 40 is prevented from falling out from within the groove. be done.

As described above, since the O-ring fall prevention device according to the present invention has the boss flesh of the bolt insertion hole of the cover member having the O-ring insertion groove protruding into the O-ring insertion groove, a comparison of the cover members The bolt insertion holes and the boss flesh portion provided on the outer periphery of the cover member can be brought closer to the center of the cover member, and this has the effect of providing a cover member having a compact O-ring insertion groove suitable for an engine oil pump, etc. be.

In addition, unlike the sealing device in the above-mentioned Japanese Utility Model Publication No. 52-127124, there is no need to provide a dedicated protrusion for press-fitting the O-ring, so design considerations such as the size, shape, and number of the protrusions should be taken into account. This has the effect of providing an O-ring fall prevention device that is extremely easy to design and manufacture.

Furthermore, since the O-ring can be elastically supported by the protruding part of the boss flesh between the bolt insertion hole and the O-ring insertion groove, the O-ring can be sufficiently compressed in other parts of the groove. Even if a gap is provided, the O-ring can be installed in the groove much more easily than in the groove, and the O-ring can be completely prevented from falling off.

Moreover, the effect of preventing the cover member from falling off has the effect of significantly improving the workability of assembling the cover member onto the main body side.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of an oil pump showing an embodiment of the present invention, Fig. 2 is a plan view of the cover of the oil pump, and Fig. 3 is an enlarged sectional view showing the state in which an O-ring is inserted into the groove of the cover. , FIG. 4 is an enlarged sectional view showing how the O-ring is attached to the protrusion of the groove. 20...Pump cover, 21...Matching surface, 2
3...O-ring insertion groove, 25...Bolt insertion hole,
26...boss meat part, 27...overhanging part, 30...
...Pump casing, 40...O ring.

Claims (1)

[Scope of utility model registration request] An O-ring fall prevention device comprising a boss portion of a bolt insertion hole of a cover member having an O-ring insertion groove that projects into the O-ring insertion groove.