JPH043194Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pipe joint that connects a steel pipe and a resin pipe.

[Conventional technology]

As shown in Fig. 2, a conventional pipe joint for connecting a steel pipe and a resin pipe is a biting ring 2 with a circular cross section, teeth 21 on the inside, and a part of the circumference cut out.
4. After inserting the retainer 22 and the packing 23 into the steel pipe 1 in this order, connect the steel pipe 1 to one end of the joint body 100 by screwing and tightening the cap nut 20 having the resin coating 19 on its outer surface. However, on the other end side, there is a saw blade-shaped tooth portion 21a inside.
It has a tapered part 32 and a protrusion 3 on the outside.
A lock ring 31 having a circumferential portion cut out, a collar 22a, and a packing 23a are sequentially inserted into the end of the resin pipe 2, and a cap nut 20a having a resin coating 19a is inserted into the joint body 100. By tightening the male screw 13a at the other end, the protrusion 30 of the lock ring 31 is pushed by the inner step 25a of the cap nut 20a, and the seal 2 is inserted through the collar 22a.
3a to the slope 26a of the packing chamber of the joint body 100
and press against the outer surface of the resin pipe 2 to seal the internal fluid, and the teeth 21a of the lock ring 31.
It is designed to be connected by biting into the outer periphery of the resin pipe 2.

[Problem that the invention attempts to solve]

The above conventional pipe joints each have a cap nut of 20, 20
a, packing 23, 23a, retainer 22, 22
a. Since the locking rings 24 and 31 for biting are installed internally, the structure is complicated and large due to the large number of components, and a large wrench must be used to tighten the connections, which requires a large area for piping work. This required difficult work in a narrow space.

[Means for solving problems]

The gist of the present invention is to provide a female thread for coupling with the inner on the inner surface of the center side, a parallel portion following the female thread, an inclined portion following the parallel portion, and a locking step portion at the end of the inclined portion. An O-ring is provided on the inner surface of the outer outer surface to abut on the outer surface of the resin pipe that engages and connects the sloped part and the step part, and an O-ring that bites into the outer surface of the resin pipe that engages and connects to the slope to prevent the resin pipe from being pulled out. A locking ring having blocking teeth, a collar abutting the end of the locking ring, an elastic ring abutting and sealing the outer surface of the resin pipe connected to the parallel portion, and a back-up spring abutting the elastic ring. , a stiffener having a cylindrical body that can be inserted into contact with the inner surface of the connecting resin pipe and having a collar that engages with the back-up spring, and a gasket that engages with the collar of the stiffener are installed in order, and the outer The inner has a female thread, an end surface on the center side end surface that engages with the gasket, a male thread on the center side outer surface for coupling with the outer, and a connection part with the pipe on the other end. The pipe joint is characterized in that the male thread is screwed onto the pipe joint, and the collar of the stiffener is held between the back spring and the gasket.

[Effect]

Since the present invention has the above-described structure, the stiffener is mounted on the outer inner surface while being elastically clamped in the axial direction via the elastic ring and the gasket. When the resin tube is inserted from the outer end, the resin tube is inserted until it is locked in the collar of the stiffener, and the inner surface of the resin tube is supported by the outer surface of the stiffener, and the stiffener and the resin tube are integrally connected to the stiffener. Even when sliding elastically in the axial direction, the outer surface of the resin tube is sealed from the inner surface by the elastic ring. On the other hand, when the lock ring is installed in a buried pipe, corrosion protection from the outside is accomplished by sealing it with an O-ring that engages the sloped portion and step portion of the outer layer and abuts the outer surface of the resin pipe. In addition, even if a large pulling force is applied to the resin tube after the resin tube is inserted, the diameter of the lock ring is reduced by the outer sloped part, and the teeth of the lock ring bite into the outer surface of the resin tube, preventing the resin tube from being pulled out. .

〔Example〕

In FIG. 1 showing an embodiment of the present invention, a female thread 33 is provided inside one end of the outer 4 to be screwed into the inner 3, and a parallel portion 1 is continuous with the female thread 33.
4, an inclined portion 15, and a step portion 16 are provided. A lock ring 6 is provided on the inner surface between the parallel portion 14 and the inclined portion 15, and the lock ring 6 has a notch on a part of the circumference and has saw blade-like biting teeth 17 on the inner surface. O between part 16
A ring 7 is interposed.

In addition, the inner surface of the parallel portion 14 is provided with a collar 10, an elastic ring 11, a back-up spring 9, and an outer diameter that can be inserted into the inner surface of a resin pipe (hereinafter referred to as a pipe) 2 such as a polyethylene pipe. A stiffener 8 having a cylindrical body and a collar 18 projecting outward at the end is inserted, and a gasket 5 is inserted.
intervene.

The outer 4 configured in this way is screwed together with the external thread 13 of the inner 3, and the above-mentioned parts are assembled between the outer 4 and the end face of the inner 3. At this time, the backup spring 9 is pressed by the lock ring 6 and the elastic ring 11 to press and fix the collar 18 of the stiffener 8. A resin coating 19 is applied to the outer surface of the assembled product in this state to prevent corrosion from the outside when the pipe is buried. The elastic ring 11 prevents internal fluid from entering the lock ring 6 side. In this state, when the tube 2 is inserted from the side end of the outer 4 to the collar 18 of the internal stiffener 8, the connection of the tube 2 is completed. After inserting the tube 2, when a pull-out force is applied to the tube 2, the lock ring 6 is reduced in diameter by the sloped portion 15 on the inner surface of the outer 4, and bites deeply into the outer surface of the tube 2 to prevent the tube 2 from being pulled out.

[Effects of the invention] As described above, the pipe joint of the present invention is smaller and lighter than conventional ones, and there is no need to rotate a cap nut to connect the pipe, and the connection can be completed simply by inserting the pipe. Therefore, no piping tools are required, and even if the piping space is small, it can be easily connected, and the connection time is greatly shortened.

Furthermore, since water does not enter the lock ring from the inner and outer surfaces of the pipe joint, the lock ring will not corrode.

In addition, when the outer surface is coated with resin, it has many effects such as preventing corrosion from the external environment when buried, etc., and further improving durability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention, and FIG. 2 is a sectional view of a main part showing a conventional pipe joint. 1...Steel pipe, 2...Resin pipe, 3...Inner,
4... Outer, 5... Gasket, 6... Lock ring, 7... O-ring, 8... Stiffener, 9... Backup spring, 10... Collar, 11... Elastic ring, 12... Inner ring. Screw, 13... Same male thread, 14... Parallel part on outer inner surface, 15... Same inclined part, 16... Same step part,
17... Lock ring bite teeth, 18... Stiffener collar, 19... Resin coating, 33...
Outer female thread.

Claims (1)

[Scope of utility model registration request] A female thread for coupling with the inner is provided on the inner surface of the center side, and a parallel portion following the female thread, an inclined portion following the parallel portion, and a locking stepped portion at the end of the inclined portion are provided on the inner surface of the outer, an O-ring that abuts the outer surface of the resin pipe that engages and connects the inclined portion and the stepped portion; and teeth that bite into the outer surface of the resin pipe that engages and connects the inclined portion to prevent the resin pipe from being pulled out. a locking ring, a collar that contacts the end of the locking ring, an elastic ring that contacts and seals the outer surface of the resin pipe connected to the parallel portion, a back-up ring that contacts the elastic ring, and a collar that contacts the end of the lock ring; A stiffener, which has a cylindrical body that can be inserted into contact with the inner surface of the resin pipe to be connected, and a gasket that engages with the collar of the stiffener are sequentially attached to the female thread of the outer, and the center The inner has an end surface that engages with the gasket on the side end surface, a male thread for coupling with the outer on the center outer surface, and a connecting portion with the pipe on the other end, and the inner male thread is screwed into the inner. A pipe joint characterized in that a stiffener collar is held between the back-up spring and the gasket.