JPH0454394Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to improvements in pipe joints for flexible pipes (hereinafter referred to as flexible pipes) used particularly for gas and water piping.

(Prior art) As a conventional pipe fitting of this type,
There is one shown in Publication No. 73193.

As shown in FIG. 4, the conventional pipe joint includes a joint body 1, a cap nut 2, a retainer 3, and a gasket 4. and retainer 3
A corrugated shape 7 that engages with the outer peripheral corrugated shape of the flexible pipe 9 is formed on the inner circumferential surface of the retainer 3, and a thick flange portion 8 is integrally formed on the rear end side of the retainer 3.

When actually connecting the flexible tube 9, the cap nut 2 is externally fitted onto the end of the flexible tube 9, and at the same time, the inner circumferential waveform 7 of the retainer 3 and the outer circumferential waveform of the flexible tube 9 are engaged. Then, after fitting the retainer 3 onto the flexible pipe 9 in the same way, the gasket 4 is interposed between the end face of the flexible pipe 9 and the pipe receiving wall portion 1a of the joint body 1, and the male screw portion 5 of the joint body 1 is inserted. When the cap nut 2 is rotated in a predetermined direction while screwing together the female screw portion 6 of the cap nut 2, the cap nut 2 presses the rear end flange portion 8 of the retainer 3 with its base 2a and connects the joint. They are sequentially tightened to the main body 1.

Then, as the cap nut 2 rotates, the flexible tube 9 is also pressed in the same direction via the retainer 3.
Compress the end portion 9a as shown in the figure to seal the gasket 4.
Since the flexible pipe 9 is brought into close contact with the joint body 1, the flexible pipe 9 is thereby connected to the joint body 1.

(Problems to be solved by the invention) However, in the case of conventional pipe joints, a male threaded portion 5 is formed on the side of the joint body 1, and the retainer 3 is inserted into the inside of the male threaded portion 5 to form a bag. Base 2a of nut 2
Since the structure is such that the rear end flange portion 8 of the retainer 3 is pressed, when an attempt is made to connect the flexible pipe 9 to the joint body 1 by rotating the cap nut 2, as the cap nut 2 rotates, The rear end flange portion 8 is strongly pressed against the base portion 2a of the cap nut 2, causing distortion such as deformation in the thin wall portion of the retainer 3 that continues from the flange portion 8, and especially the inner periphery of the retainer 3 and the flexible tube 9. Since frictional resistance increases unnecessarily between the contact surface with the outer circumference and the contact surface between the rear end flange portion 8 of the retainer 3 and the base portion 2a of the cap nut 2, the rotation of the cap nut 2 causes
There was a problem in that the flexible tube 9 rotated together with the retainer 3, resulting in poor sealing performance.

Furthermore, in the conventional pipe joint described above, since the retainer 3 and gasket 4 are not made of electrically insulating material, stray currents generated by grounding of heavy DC electrical equipment such as railways and underground piping can be avoided. There was also a major problem in that the pipe fittings themselves were subject to electrical corrosion due to the electric current generated by the battery action, significantly shortening the life of the pipes.

Further, Japanese Patent Application Laid-Open No. 129583/1983 discloses that the sleeve and the packing are made of electrically insulating members, but the above-mentioned structure for preventing co-rotation is not solved.

(Means for solving the problems) Therefore, the present invention was developed to effectively solve the problems of the conventional pipe joints, and includes at least a main body of the joint, a bush, a retainer, and a gasket. In a pipe joint having a structure in which a flexible pipe is connected to a main body of the joint, a female thread portion is formed on the main body of the joint, a male thread portion is formed on the bush to be screwed with the female thread portion, and a wavy shape is formed on the inner periphery. A flange portion that is pressed by the tip end surface of the male threaded portion of the bushing is formed at the end of the joint main body side of the retainer, and further, the inner circumferential surface of the male threaded portion of the bushing is spaced from the outer circumferential surface of the retainer; A configuration in which the gasket is molded from electrically insulating material was adopted.

(Function) Accordingly, in the present invention, a female threaded portion is formed on the joint main body side, a male threaded portion is formed on the bushing side, and a flange portion is formed at the end of the retainer on the joint main body side, The flange portion is pressed by the tip end surface of the male thread of the bushing, so when the joint body and the bush are tightened, the flange portion of the retainer is pressed by the tip end surface of the male thread portion of the bushing, and The thin wall part of the retainer that continues from the flange part is
Since the retainer is not in direct contact with the inner wall surface of the male threaded portion, the retainer does not suffer from distortion due to deformation or the like as in the conventional case.

In addition, in the present invention, since the retainer and gasket are made of an electrically insulating material, electrical corrosion caused by stray running current or battery action of buried piping can be effectively prevented, unlike in the past. It becomes possible to do so.

(Example) Hereinafter, the present invention will be described in detail based on an illustrative example.

The pipe joint according to the first embodiment also includes a joint main body 11, a bush 12, and a retainer 13, as shown in FIG.
It is equipped with a gasket 14 and a gasket 14, and its feature lies in the following configuration.

That is, in this embodiment, unlike the conventional case, a female threaded portion 16 is formed on the joint main body 11 side, and a male threaded portion 15 that screws with the female threaded portion 16 is formed on the bush 12 side.
, so that when both 11 and 12 are tightened, the male threaded portion 15 of the bushing 12 is screwed into the inside of the joint main body 11.

Further, the retainer 13 is similar to the conventional one in that a waveform 17 is formed on the inner circumferential surface to engage with the outer circumferential waveform of the flexible tube 19, but in this embodiment, it is divided into two parts in the longitudinal direction. In addition, the thick flange portion 18 is formed at the tip of the retainer 13, that is, at the end on the joint main body 11 side, so that when the bush 12 rotates, the flange portion 18 is connected to the male screw portion of the bush 12. No. 15 is configured to be pressed by the tip end surface.

In this embodiment, in addition to this configuration, the above-mentioned split type retainer 13 and gasket 14 are provided.
The device is characterized in that it is made of an electrically insulating material such as synthetic resin or ceramics.

Therefore, when connecting the flexible pipe 19 to the joint body 11 using the pipe joint of the first embodiment, first, the bush 12 is fitted onto the end of the flexible pipe 19, and at the same time, the retainer 13 made of insulating material is fitted. Waveform shape 17
After the split retainer 13 is fitted onto the flexible pipe 19 at the same time, an insulating material is applied to the end face of the flexible pipe 19 and the pipe receiving wall 11a of the joint main body 11. When the bush 12 is rotated in a predetermined direction while the female thread part 16 of the joint main body 11 and the male thread part 15 of the bush 12 are screwed together with a gasket 14 made of
is sequentially tightened to the joint main body 11 while pressing the distal end flange portion 18 of the retainer 13 with the distal end surface of the male thread portion 15.

Then, as the bush 12 rotates, the second
As shown in the figure, the flexible pipe 19 is also pressed in the same direction via the retainer 13, compressing the end portion 19a as shown in the figure and bringing the gasket 14 into close contact with the flexible pipe 19. It will be connected to.

However, in this embodiment, unlike the conventional case, a female thread part 16 is formed on the joint main body 11 side, a male thread part 15 is formed on the bush 12 side, and a thick flange part is formed on the tip of the retainer 13. form 18,
The flange portion 18 is connected to the male screw portion 15 of the bush 12.
Since the structure is such that the pressure is applied at the tip end surface, when the joint main body 11 and the bush 12 are tightened, the retainer 1
The tip flange portion 18 of No. 3 is pressed by the tip of the male screw portion 15 of the bush 12, and the thin wall portion of the retainer 13 continuing from the flange portion 18 is not in direct contact with the inner wall surface of the male screw portion 15. There is almost no risk of distortion due to deformation etc.

Therefore, even if the inner circumference of the retainer 13 and the flexible pipe 1
Even if frictional resistance occurs between the contact surface with the outer periphery of the retainer 13, the contact surface between the outer periphery of the retainer 13 and the inner wall of the male threaded portion 15, and the contact surface between the flange portion 18 and the male threaded portion 15, these frictions The total resistance is the joint main body 11
This is inevitably smaller than the frictional resistance generated between the contact surfaces of the gasket 14 and the contact surfaces of the gasket 14 and the flexible pipe 19, so that the flexible pipe 19 is completely prevented from rotating together with the rotation of the bush 12. The Rukoto.

Moreover, in this embodiment, since the retainer 13 and gasket 14 are made of electrically insulating material, it is possible to reliably prevent electrical corrosion caused by stray currents, battery action of buried piping, etc. Therefore, it is possible to guarantee a long life of the pipe joint.

Further, FIG. 5 is a perspective view showing another example of the retainer 13 according to the first embodiment, and as shown in the same figure, the retainer 13 is constructed such that both retainer pieces are connected together by providing a hinge 13a. It may be configured.

Next, the pipe joint according to the second embodiment will be explained.
This embodiment is based on the entire structure of the first embodiment, but the difference is that, as shown in FIG. Two engaging protrusions 18
a are integrally formed, and lock grooves 16a that engage with the respective engagement protrusions 18a are also formed oppositely on the surface of the female threaded portion 16 of the joint main body 11, so that the engagement protrusions for the respective lock grooves 16a are formed integrally with each other. 18a, the retainer 13 is connected to the female screw portion 16 of the joint main body 11.
It is designed so that it can be reliably locked inside the device.

Therefore, in the second embodiment, the bush 12
When the retainer 1 is rotated, each engagement protrusion 18a formed on the flange portion 18 is engaged with a locking groove 16a formed on the female screw portion 16, and the retainer 1 is rotated.
The joint body 11 is linearly moved without co-rotating 3.
Since the flexible pipe 19 can be guided inside the flexible pipe 19, it is possible to prevent the flexible pipe 19 from rotating together and deteriorating the sealing performance more reliably than in the first embodiment.

Further, FIG. 6 is a perspective view showing another example of the retainer 13 according to the second embodiment, and as shown in the same figure, the retainer 13 is constructed such that both retainer pieces are connected together by providing a hinge 13a. It may be configured.

(Effects of the invention) As described above, the present invention is characterized in that the retainer and gasket are made of an electrically insulating material, so that stray currents generated by grounding of heavy DC electrical equipment such as railways, etc. It becomes possible to reliably prevent the pipe joint itself from being electrically corroded as in the past due to the electric current generated by the battery action of underground pipes.

Therefore, the life of the pipe joint can be extended with an extremely simple structure.

Furthermore, in the present invention, a female thread is formed in the main body of the joint, a male thread is formed in the bush to engage with the female thread, and the tip surface of the male thread of the bush is formed at the end of the retainer on the side of the main body of the joint. Since the retainer is characterized by a flange portion that is pressed by the bushing, when the joint body and the bushing are tightened, the flange portion of the retainer is pressed by the tip surface of the male thread portion of the bushing, and the flange portion Since the thin portion of the retainer continuing from the retainer does not directly contact the inner wall surface of the male threaded portion, the retainer does not suffer from distortion due to deformation or the like as in the conventional case.

Therefore, even if frictional resistance occurs between the contact surface between the inner periphery of the retainer and the outer periphery of the flexible pipe, the contact surface between the outer periphery of the retainer and the inner wall of the male threaded portion, and the contact surface between the flange portion and the male threaded portion. However, the sum of these frictional resistances does not become the resistance force that causes the flexible pipe to rotate together due to the rotation of the bushing. Therefore, with an extremely simple structure, the simultaneous rotation of the flexible pipe can be completely prevented, and the sealing performance can be improved. This will also contribute to the improvement of

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing a pipe joint according to a first embodiment of the present invention, and FIG. 2 is a half-sectional view showing a state in which flexible pipes are connected using the pipe joint of the first embodiment.
FIG. 3 is an exploded perspective view showing a pipe joint according to the second embodiment, FIG. 4 is a half-sectional view showing a state in which flexible pipes are connected using a conventional pipe joint, and FIGS. 5 and 6 are FIG. 7 is a perspective view showing other examples of retainers used in the present invention. 11... Joint main body, 12... Button, 13...
...Retainer, 15...Male thread part, 16...Female thread part, 18...Flange part, 19...Flexible pipe.

Claims (1)

[Scope of utility model registration request] In a pipe joint having a structure in which a flexible pipe is connected to the joint main body, the joint main body is provided with at least a joint main body, a bush, a retainer, and a gasket, and a female thread portion is formed on the joint main body, and a male screw thread is formed on the bush to be screwed with the female thread portion. At the same time, a flange portion which is pressed by the tip end surface of the male threaded portion of the bushing is formed on the end of the joint main body side of the retainer having a waveform shape on the inner periphery, and further, a flange portion is formed on the end surface of the male threaded portion of the bushing. A pipe joint characterized in that the outer peripheral surface of the retainer is spaced apart, and the retainer and the gasket are made of an electrically insulating material.