JP2550526Y2 - Bayonet fitting - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention relates to a bayonet joint used for connecting pipes in a water piping system such as water supply and sewerage.

[Conventional technology]

Generally, in this type of joint, a metal connecting pipe such as a steel pipe whose inner surface is subjected to corrosion protection is inserted into the joint main body, and a C-shaped retaining ring held in the joint main body is attached to the outer peripheral surface of the connecting pipe. The connection pipe is prevented from coming off by being pressed into the connection pipe, and furthermore, the both are sealed by packing which is held by the joint body and pressed against the outer peripheral surface of the connection pipe.

[Problems to be solved by the invention]

By the way, in this type of joint, since the length of the connection pipe is adjusted by cutting it on site, when the connection pipe is inserted into the joint body, the cut surface becomes an obstacle, and the work is troublesome. Therefore, in order to facilitate the insertion work, there is an annoyance that the edge of the connection pipe must be largely chamfered.

Further, if the connection pipe is connected to the joint body with the cut end face, the end face will be corroded, and the sealing property of this portion will be impaired. For this reason, an O-ring pressed against the end face of the connection pipe may be provided in the joint body to prevent corrosion of the pipe end. However, in this type of joint, when inserting the connection pipe, the retaining ring is attached to the connection pipe. Since the allowance required for displacing the outer peripheral surface is taken into account, it is difficult to accurately contact the O-ring with the pipe end face of the connecting pipe, which is not practical.

The present invention has been made in view of the above-mentioned circumstances, and aims at facilitating the work of inserting the connecting pipe and reliably preventing the connecting pipe from being inserted, and at the same time, the end face of the connecting pipe due to internal water leakage. An object of the present invention is to provide a bayonet joint capable of reliably preventing corrosion.

[Means for solving the problem]

In order to achieve the above object, the insertion joint according to the present invention has a pull-out force after insertion of the connection pipe into a joint body into which a metal connection pipe having an anticorrosion lining layer formed on an inner peripheral surface is inserted. A C-shaped retaining ring which is reduced in diameter by being pressed into the outer peripheral surface of the connecting pipe in a biting manner to prevent it from coming off, and a first joint having a first annular packing pressed against the outer peripheral surface of the connecting pipe. And a seal portion provided on the outer peripheral surface of the body portion and sealing between the inner peripheral surface of the connection tube and the outer peripheral surface of the body portion. A flange having an end surface integrally formed with the body portion and abutting against an end surface of the connection pipe, and an outer peripheral surface of the collar section being substantially flush with an outer peripheral surface of the connection pipe. Is set as
A tapered annular tapered surface extending from the outer peripheral surface of the collar portion is formed at the distal end edge of the collar portion of the core, and is pressed into contact with the outer peripheral surface of the collar portion of the core in the joint body. It is characterized in that two annular packings are arranged.

[Action]

According to this invention, since the body portion is fitted into the end portion of the connection pipe, a tapered annular tapered surface is formed at the leading edge of the core connected to the connection pipe.
The connection pipe can be easily inserted into the joint body by using the tapered surface without chamfering the end edge of the connection pipe.

In addition, the tapered surface of the core extends from the outer peripheral surface of the collar portion of the core, and the outer peripheral surface of the collar portion is set so as to be substantially flush with the outer peripheral surface of the connection pipe. Even though the C-shaped retaining ring, the first annular packing, and the second annular packing are arranged in the joint body, the core and the core are attached to the retaining ring and the first and second annular packings. The end of the connecting pipe can be easily inserted. That is, when the connection pipe connecting the core to the joint body is inserted, when the core is inserted into the above-described retaining ring or the first and second annular packings, the tapered surface of the collar portion of the core is inserted. Since the core acts as a guide surface, the core does not catch on the retaining ring or the first and second annular packings to prevent the insertion operation, and the connecting pipe to which the core is connected does not have the retaining ring or the like. When inserted into the first annular packing, the outer peripheral surface of the brim portion of the core is set so as to be substantially flush with the outer peripheral surface of the connection pipe.
The retaining ring or the first annular packing that has moved from the tapered surface of the brim to the outer peripheral surface smoothly transitions from the outer peripheral surface of the core to the outer peripheral surface of the connecting pipe. There is no occurrence of a situation in which the plugging work is hindered by the ring or the first annular packing and the annular packing is damaged.

Also, when a pull-out force is applied after the connection pipe is inserted, the diameter of the C-shaped retaining ring is reduced, and the retaining ring is pressed into the outer peripheral surface of the connecting pipe in a press-fit manner to securely prevent the connecting pipe from coming off. It is possible to

In addition, in the plug-in connection state, the first annular packing and the second annular packing arranged on the joint body side are respectively formed on both sides of the end face of the connection pipe with the outer peripheral surface of the connection pipe and the flange of the core. These parts are separately pressed against the outer peripheral surface to seal those portions, and furthermore, a seal portion provided on the outer peripheral surface of the body of the core provides a seal between the inner peripheral surface of the connection pipe and the outer peripheral surface of the body of the core. Is sealed, so that the end face of the connection pipe is shut off from both the outside and the inside by the first and second annular packings and the seal portion described above. Corrosion of the end face of the connection pipe due to the leakage of water is reliably prevented.

〔Example〕

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

FIG. 1 is a semi-longitudinal sectional view showing an example of the bayonet joint according to the present invention.

In FIG. 1, reference numeral 1 denotes a joint body, and 2 denotes a connection pipe made of a steel pipe which is inserted into and connected to the joint body 1. An inner peripheral surface of the connection pipe 2 is made of polyethylene, vinyl chloride, or the like for rust prevention. The lining layer 3 is formed.

An annular groove 4 is formed on the inner peripheral surface of the joint body 1, and the inner peripheral surface of the annular groove 4 is formed as a tapered surface 4 b whose diameter gradually decreases toward the insertion port 4 a of the connection pipe 2. In the annular groove 4 having such a tapered surface 4b, after the connecting pipe 2 is inserted into the joint body 1 from the insertion port 4a, the diameter is reduced by the tapered surface 4b by a pulling force. A trapezoidal C-shaped retaining ring 5 having a trapezoidal cross section is disposed so as to securely press against the outer peripheral surface of the connection pipe 2 in a biting manner. Reference numeral 6 denotes a first annular recess formed on the inner peripheral surface of the joint main body 1 at a position parallel to the annular groove 4, and a tongue piece 7 a is provided in the annular recess 6. A first annular packing 7 for sealing, which is in pressure contact with the outer peripheral surface of the second, is arranged.

Reference numeral 8 denotes a synthetic resin cylindrical core mounted on the end 2a of the connection pipe 2. The core 8 is provided at the end 2a of the connection pipe 2.
And a body portion 9 fitted inside the body portion 9, held on the outer circumferential surface of the body portion 9 and in contact with the inner circumferential surface of the connecting tube 2, and the inner circumferential surface of the connecting tube 2 and the outer circumferential surface of the body portion 9. An O-ring 17 serving as a seal portion for sealing the gap therebetween, and a flange portion 10 integrally formed at the tip of the body portion 9 and having an end face 10b abutting against the end face 2b of the connection pipe 2. I have. The O-ring 17 is
It is held between annular ribs 15, 16 formed integrally with the body 9. When the body 9 is fitted inside the end of the connection pipe 2 and the end face 2b of the connection pipe 2 is brought into contact with the end face 10b of the collar 10, the outer peripheral face 10a of the collar 10 is It is set so as to be substantially flush with the outer peripheral surface. Further, the outer peripheral surface 10 of the collar 10 is attached to the leading edge of the collar 10 of the core 8.
A tapered annular tapered surface 11 extending from a is formed. Reference numeral 12 denotes a stopper wall formed on the inner peripheral surface of the joint body 1 and abutting on the distal end surface of the core 8.

13 is the joint body 1 corresponding to the flange 10 of the core 8.
A second annular packing 14 coupled to the packing 7 is disposed in the annular recess 13, and an inner periphery of the packing 14. The face-side fold 14a is in pressure contact with the outer peripheral surface 10a of the collar 10.

In the figure, reference numeral 18 denotes a synthetic resin powder lining formed on a part of the inner peripheral surface of the joint body 1.

In the above configuration, when connecting the connecting pipe 2 to the joint body 1, the body 8 of the core 8 is inserted into the end of the connecting pipe 2 so that the core 8 is connected to the end face 2 b of the connecting pipe 2. The connecting pipe 2 is inserted from the insertion port 4a of the joint body 1 with the core 8 in front, and the leading end of the core 8 contacts the stopper wall 12 with the core 8 facing forward. Let it. Thereafter, when a slight pulling force is applied to the connecting pipe 2, the retaining ring 5 is reduced in diameter by the inner peripheral tapered surface 4b of the annular groove 4 in the joint body 1, and the retaining ring 5 is removed.
Is pressed into the outer peripheral surface of the connection pipe 2 in a biting manner,
The connecting pipe 2 is connected to the joint body 1 while being prevented from falling off.

When the connecting pipe 2 is inserted into the joint main body 1 as described above, the tapered annular tapered surface 11 formed on the leading edge of the core 8 serves as a guide surface at the time of insertion.
The connection pipe 2 can be easily inserted into the joint body 1.

Moreover, in addition to the core 8 having the tapered surface 11 extending from the outer peripheral surface 10a of the collar portion 10, the outer peripheral surface 10a of the collar portion 10 of the core 11 is substantially flush with the outer peripheral surface of the connection pipe 2. Are set in a continuous shape, so that C
Despite the arrangement of the U-shaped retaining ring 5, the first annular packing 7, and the second annular packing 14,
Their retaining rings 5 and first and second annular packings
The ends of the core 8 and the connection pipe 2 can be easily inserted into the 7, 14. That is, when the connecting pipe 2 connected to the core 8 is inserted into the joint main body 1, when the collar portion 10 of the core 8 is inserted into the retaining ring 5 or the first and second annular packings 7, 14, the collar is inserted. Since the tapered surface 11 of the portion 10 acts as a guide surface at the time of insertion, the collar portion 10
And the first and second annular packings 7, 14 are not hindered by the insertion operation. Moreover, when the connecting pipe 2 to which the core 8 is connected is inserted into the retaining ring 5 or the first annular packing 7, the tapered surface 11 of the flange 10 of the core 8 is fixed to the outer peripheral surface 10 of the collar 10.
a from the taper surface 11 of the core 8 to the outer peripheral surface by being set so that the outer peripheral surface 10a of the flange portion 10 is substantially flush with the outer peripheral surface of the connecting pipe 2. The retaining ring 5 and the first annular packing 7 that have been smoothly transferred
Is smoothly transferred from the outer peripheral surface 10a of the brim portion 10 of the core 8 to the outer peripheral surface of the connecting pipe 2.
Is prevented from being caught by the retaining ring 5 or the first annular packing 7 and hindering the insertion operation.

In the above-mentioned connection state, since the fold portion 14a of the second annular packing 14 is pressed against the outer peripheral surface 10a of the flange portion 10 of the core 8, for example, the C-shaped retaining ring 5
Connection pipe 2 to make sure
Is slightly displaced in the withdrawal direction, whereby the core 8 is displaced.
Even if there is a slight gap between the end face 10b of the flange 10 and the end face 2b of the connecting pipe 2, it is possible to reliably prevent corrosion such as rust on the end face 2b of the connecting pipe 2. . To explain this more specifically, in the plug-in connection state, the first annular packing 7 and the second annular packing 14 arranged on the joint main body 1 side are respectively disposed on both sides of the end face 2b of the connection pipe 2. Outer peripheral surface of connecting pipe 2 and brim of core 8
The outer circumferential surface 10b of the core 10 is pressed against each other to seal those portions, and the inner circumferential surface of the connecting pipe 2 and the body 9 are sealed by an O-ring 17 held on the outer circumferential surface of the body 9 of the core 8. The end face 2b of the connecting pipe 2 is shielded from both the outside and the inside by the first and second annular packings 7, 14 and the O-ring 17 because the outer peripheral surface of the connecting pipe 2 is sealed. , End face 2b of connecting pipe 2 due to intrusion water from the outside or leakage from the inside
Corrosion is reliably prevented.

Even if there is a margin for insertion of the connecting pipe 2, regardless of this, the second annular packing 14 and the brim portion of the core 8 are connected.
Since the pressure contact position of the outer peripheral surface 10a with the outer peripheral surface 10a only changes within the width of the outer peripheral surface 10a, it is possible to prevent infiltration water and internal water from reaching the end surface 2b of the connection pipe 2 regardless of the above-mentioned allowance. Thus, the function of preventing corrosion of the end face 2b of the connection pipe 2 can be ensured.

By the way, in the above embodiment, the second packing 14 is described as being integrally formed with the first packing 7,
Each may be independent, and the shape and the like can be arbitrarily changed like packings 21 and 22 having a substantially circular cross section as shown in FIG.

The retaining ring 5 is not limited to the one described above.
Needless to say, a retaining ring 23 having a missing circle having a shape as shown in the figure can be used.

[Effect of the invention]

As described above, according to the present invention, the connecting pipe and the core mounted on the connecting pipe can be easily and easily attached to the joint body, the retaining ring disposed on the joint body side, and the first and second annular packings. Since it becomes possible to insert the connection pipe easily, not only the operation of inserting the connecting pipe into the joint body can be facilitated, but also the situation where the annular packing is damaged during the insertion operation does not occur. Also, the C-shaped retaining ring is reduced in diameter by the pulling force after the connection pipe is inserted, and the retaining ring is bitingly pressed into contact with the outer peripheral surface of the connection pipe to reliably prevent the connection pipe from coming off. be able to. In addition, in the insertion connection state, even if the connecting pipe is displaced in the pulling-out direction and a slight gap is formed between the end face of the flange portion of the core and the end face of the connecting pipe, it is possible to prevent water from entering from the outside or the inside. The effect that the situation where the end face of the connection pipe is corroded by water can be reliably prevented is achieved.

[Brief description of the drawings]

FIG. 1 is a semi-longitudinal sectional view showing an embodiment of the plug-in joint according to the present invention, and FIG. 2 is a semi-longitudinal sectional view showing another embodiment of the plug-in joint according to the present invention. 1 ... joint body, 2 ... connecting pipe, 2a ... end of connecting pipe,
2b ... End face of connecting pipe, 3 ... Corrosion-proof lining layer, 5,23
... C-shaped retaining ring, 7, 21 ... first annular packing, 8 ... cylindrical core, 9 ... trunk, 10 ... collar, 10a
... Collar outer peripheral surface, 10b collar end surface, 11 taper surface, 14, 22 second annular packing, 17 O-ring (seal part).

Claims (1)

(57) [Scope of request for utility model registration] An inner peripheral surface of a joint body into which a metal connection pipe having an anticorrosive lining layer formed is inserted, the diameter of which is reduced by a pulling force after the connection pipe is inserted, and an outer peripheral surface of the connection pipe. A C-shaped retaining ring which presses against the outer peripheral surface of the connecting pipe and a first annular packing which presses against the outer peripheral surface of the connecting pipe; A sealing portion provided on an outer peripheral surface of the trunk portion to seal between an inner peripheral surface of the connecting pipe and an outer peripheral surface of the trunk portion; and a connection portion integrally formed with the trunk portion. A flange having an end surface that is in contact with an end surface of the pipe, and an outer peripheral surface of the collar portion is set so as to be substantially flush with an outer peripheral surface of the connection pipe. Tapered from the outer periphery of the collar A plug-in joint, wherein an annular tapered surface is formed, and a second annular packing pressed into contact with the outer peripheral surface of the collar portion of the core is disposed in the joint body.