JPS6021597Y2 - Sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing device provided at a connection portion of a fuel pipe in, for example, an automobile.

To explain such a conventional sealing device with reference to FIGS. 1 to 3, an annular groove 2 is provided in an inner pipe 1 at a connecting portion of a fuel pipe that fits inside and outside, and an O-ring 3 is provided in this annular groove 2. At the same time, the outer tube 4 is formed with a chamfer 5 whose inner diameter increases toward its end.

Before connection, the outer diameter of the bottom part of the annular groove 2 is set to a
1 The inner diameter of the outer tube 4 is b10 The outer diameter of the ring 3 is c, the wire diameter of the ring 3 is 41, and the maximum inner diameter of the chamfer 5 is e, then the values of a to e are selected so that the following relationship holds. ing.

b<c c<e b -a <2d As a result, the end of the inner tube 1 is slid through the chamfer 5 of the outer tube 4 to the inner diameter portion (Fig. 2), and the end of the inner tube 1 is slid in the radial direction of the O-ring 3. Appropriate sealing pressure is generated by the elastic deformation of
A good liquid-tight seal can be obtained.

However, when the end of the inner tube 1 is slid in, the O-ring 3 gets caught between the outer circumferential surface of the inner tube 1 and the inner circumferential surface of the outer tube 4 at the chamfer 5, as shown in FIG. This has caused many problems such as difficulty in assembly and inability to obtain a good seal.

The present invention provides a sealing device that can effectively prevent O-rings from getting caught during assembly.

In order to achieve this objective, according to the present invention, an annular groove is provided in the inner tube of the piping connection part that fits inside and outside, and an O-ring provided in this annular groove allows the inner tube and the outer tube into which it fits to be fluidly connected. In a sealing device that tightly seals, an inner diameter expanded portion is formed on the open end side of a connecting portion of an outer tube, a cover member is provided that surrounds the outer periphery of the connecting portion of the inner tube, and the cover member is attached to the outer tube. Before inserting the inner tube into the tube, the O-ring is compressed from the outside in the radial direction to make the outer diameter of the 01J ring approximately equal to the inner diameter of the outer tube beyond the expanded inner diameter portion. The diameter is approximately equal to the inner diameter of the inner diameter expanded portion of the outer tube, the O-ring is located deeper than the inner diameter expanded portion of the outer tube, and the cylindrical portion of the cover member is located at the inner diameter expanded portion of the outer tube.

An embodiment of the present invention will be described with reference to FIG. 4 and subsequent figures.

At the connecting portion of the pipes that fit inside and outside, the inner pipe 8 has a reduced outer diameter 9 with a predetermined dimension in the axial direction, and the annular groove 10 is sufficiently close to the end of the inner pipe 8. Reduction part 9
provided on the outer periphery of the

An O-ring 11 is placed within this annular groove 10.

A cover 12 made of rubber, synthetic resin, or the like is fitted into the reduced portion 9 so as to surround the outer periphery of the reduced portion 9, and has an end 13 in contact with a stepped portion at the end of the reduced portion 9, and an annular groove. 10
It has a corrugated portion 14 that is located closer to the end 13 and is given flexibility in the axial direction, and a cylindrical portion 15 that compresses the O-ring 11 radially inward.

The outer tube 16 has an enlarged portion 17 at its end with an enlarged inner diameter.

Figures 4, 5, and 6 show the before, midway, and post-assembly states, respectively; in the previous state (Fig. 4), O The following relationship is established between the outer diameter of the ring 11, the outer diameter 1 of the cylindrical portion 15 of the cover 12, the inner diameter m of the expanded portion 17, and the inner diameter n of the outer tube 16 deeper than the expanded portion 17. Dimensions are selected.

K〉n 1 m In this way, the end of the inner tube 8 is inserted into the expanded portion 17 of the outer tube 16, and the end of the cylindrical portion 15 comes into contact with the stepped portion at the end of the expanded portion. 14 is reduced in the axial direction and O-ring 1
1 is pulled out from the cover 12 and sent deeper than the expanded portion 17, that is, into a portion with an inner diameter n.

After assembly, the cover 12 serves as a dust cover to prevent foreign matter from entering the connection.

The end 13 of the cover 12 may protrude inwardly and be secured within an annular groove 19 on the outer periphery of the inner tube 8, as shown in FIG.

Furthermore, a partial chamfer 20 as shown in FIG. 8 may be provided at the stepped portion at the end of the expanded portion 17.

Further, the cylindrical portion 15 of the cover 12 may be provided with an annular mandrel.

As described above, according to the present invention, the cylindrical portion of the cover member has an outer diameter approximately equal to the inner diameter of the inner diameter expanded portion of the outer tube, and compresses the O-ring from the outside in the radial direction. When inserting the inner tube into the outer tube, the five cylindrical portions of the cover member are smoothly inserted into the inner diameter expanded portion of the outer tube.

Furthermore, as the inner tube is further inserted into the outer tube, the cylindrical portion of the cover member is kept in the expanded inner diameter section due to its outer diameter dimension, whereas the O-ring is sent deeper than the expanded inner diameter section. Therefore, sealing is performed between the inner circumference of the outer tube and the outer circumference of the inner tube.

When the 01J ring advances from the inner diameter expansion part to the back, the O-ring has an outer diameter that is almost equal to the inner diameter at the back due to the cylindrical part of the cover member, so the O-ring will not get caught and the assembly will be performed smoothly. be able to.

[Brief explanation of the drawing]

Figures 1, 2, and 3 are diagrams showing the prior art before assembly, after assembly, and during assembly, respectively;
5 and 6 are views showing the embodiment of the present invention before assembly, during assembly, and after assembly, respectively, and FIG. 7 shows another example of fixing the end of the cover. FIG. 8 is a diagram showing chamfering of the expanded portion of the outer tube. 8... Inner tube, 10... Annular groove, 11.
...OIJ, 12...Cover, 15
...Cylinder part, 16...Outer tube, 17...
...Extension section.

Claims (1)

[Scope of utility model registration request] In a sealing device, an annular groove is provided in the inner pipe of a piping connection part that fits inside and outside, and an O-ring provided in the annular groove seals the inner pipe and the outer pipe into which it is fitted in a liquid-tight manner. An inner diameter expanded portion is formed on the open end side, and a cover member is provided that surrounds the outer periphery of the connection portion of the inner tube, and the cover member protects the O-ring from the outside in the radial direction before inserting the inner tube into the outer tube. It has a cylindrical part that is compressed from the side to make the outer diameter of the O-ring approximately equal to the inner diameter of the inner diameter of the outer tube beyond the inner diameter expansion part, and the outer diameter of the cylindrical part is approximately equal to the inner diameter of the inner diameter expansion part of the outer tube. ,01J
The sealing device is characterized in that the ring is located deeper than the inner diameter expanded portion of the outer tube, and the cylindrical portion of the cover member is located at the inner diameter expanded portion of the outer tube.