JPS6111566Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an O-ring fall prevention device.

Conventionally, a casing member or a cover member is installed with the sealing surface in which the 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 it is covered with a cover. For products with a sealing section constructed by
1 was larger than the width of the O-ring, so there was a problem that the O-ring would fall 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 disadvantage of increasing costs and 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. Therefore, when designing and manufacturing the device, the size, shape, and number of the protrusions must be taken into consideration, which is extremely difficult.

Furthermore, in the sealing device, since the width of the groove is not uniform over the entire circumference, when the groove is processed by cutting or the like, there is a problem that it cannot be manufactured by mere profile cutting. Furthermore, even when the carburetor component is formed by die casting or the like, finishing of the grooves is required, and the same problems as described above occur during the finishing.

The present invention was devised in view of the above-mentioned drawbacks and inconveniences, and aims to provide an O-ring fall prevention device that is extremely easy to design and manufacture.
The gist thereof lies in an O-ring drop-off prevention device that includes a positioning pin that partially protrudes into an O-ring insertion groove.

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

The figure shows an embodiment of an oil pump for an engine, where 10 is a pulley for driving the oil pump, 20 is a pump cover, and a drive shaft 11 fixed to the pulley 10 passes through the pump cover 20 and connects to the outer rotor ( It extends into the pump casing 30 formed by the cylinder body 3 housing the vane) 32, and has screws 3 attached to the inner rotor 31.
It is fixed by 5 etc. Further, 21 is a mating surface that becomes a sealing surface of the pump cover 20, and 33 is a side surface of the cylinder body that faces this.

As shown in FIGS. 1 and 2, an annular O-ring insertion groove 36 having the same width t1 is formed around the outer periphery of the casing 30 on the side surface 33 of the cylinder body 3. Further, on its outer periphery, there are screw holes 37 for screwing together bolts for attaching the cover 20 to the cylinder body 3.
are formed in multiple numbers.

Note that the width t1 of the O-ring insertion groove 36 is larger than the O-ring 50 width to, and is set with sufficient consideration to the crushing margin.

Further, when assembling the cover 20 to the cylinder body 3, the dowel pin 40 as a positioning pin is inserted into the cylinder body and the cover 20 so that a part thereof protrudes into the O-ring insertion groove 36. .

The protrusion amount t2 may be an amount that can elastically press the width to of the O-ring 50 as shown in FIG.

As a result, when the O-ring 50 is fitted into the groove 36, the O-ring 50 is elastically pressed against the dowel pin 40, so that it is prevented from falling out of the groove.

As described above, the O-ring drop-off prevention device according to the present invention has the positioning pin partially protruding into the O-ring insertion groove, and has the following effects.

In other words, in order to provide a device to prevent O-rings from falling off, it is only necessary to change the setting position of the positioning pin, and there is no need to add new parts or machining steps compared to conventional sealing surface members. This has the effect of providing an O-ring fall prevention device that is extremely easy to design and manufacture and is inexpensive.

In addition, since the width of the O-ring insertion groove is uniform over the entire circumference, groove machining is extremely easy compared to the seal device in the above-mentioned Utility Model Application Publication No. 52-127124, in which the groove width varies. In addition to the above-mentioned effects, the present invention has the effect of providing an O-ring fall prevention device that is easy to design and manufacture.

Furthermore, just by fitting the O-ring into the O-ring insertion groove, it automatically comes into pressure contact with the positioning pin to prevent it from falling off, and its falling-off prevention effect also makes it easier to assemble a member with a sealing surface to a mating member. It also has the effect of significantly improving workability.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view taken along the - line in Fig. 2 of an oil pump showing an embodiment of the present invention, Fig. 2 is a side view of the cylinder serving as the oil pump casing, and Fig. 3
The figure is an enlarged cross-sectional view showing how the O-ring is inserted into the groove.
FIG. 3 is an enlarged view showing a state in which the ring is pressed into contact with the ring. 3... Cylinder body, 20... Pump cover, 30... Casing, 36... O-ring insertion groove, 40... Knock pin, 50... O-ring.

Claims (1)

[Scope of utility model registration request] An O-ring fall prevention device consisting of a positioning pin that partially protrudes into the O-ring insertion groove.