JPH0730865B2 - Pipe fitting - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pipe joint to which a connecting pipe forming a water supply pipe, an oil supply pipe, or the like is connected.

(Prior Art) For resin pipes or composite pipes of resin and metal used for water supply pipes, oil supply pipes, etc., pipe joints are used for connecting pipes or for connecting predetermined equipment. In particular, a pipe joint with a slit ring can reliably prevent water leakage and is excellent in connection strength with the connecting pipe. Such a pipe joint is disclosed in Japanese Utility Model Laid-Open No. Sho 61-22991, if it falls.
This pipe joint has an outer cylinder and an inner cylinder that are concentrically arranged, and a plurality of axial slits are provided at the end of the outer cylinder.
A tightening nut is screwed into this outer cylinder, and by inserting a connecting pipe between the inner cylinder and outer cylinder and screwing in the tightening nut, the end of the outer cylinder is compressed inward and the connection is made. The connecting pipe is joined to the pipe joint by pressing the pipe against the inner cylinder. Further, the inner peripheral surface of the connecting pipe is brought into close contact with the seal member fitted on the inner cylinder to ensure a reliable seal between the connecting pipe and the inner cylinder.

(Problems to be solved by the invention) In such a pipe joint, unless the end portion of the connecting pipe is inserted into the inner depth portion between the inner cylinder and the outer cylinder in the pipe joint, The end of the connection pipe cannot be reliably sealed in a watertight manner, and the joint body and the connection pipe cannot be joined with a predetermined connection strength.

Therefore, for example, a peep hole for confirming that the end portion of the connecting pipe is inserted to a predetermined position is provided in the outer cylinder of the joint body, and the peep hole is inserted when the end portion of the connecting pipe is inserted into the joint body. The position of the end of the connecting pipe is confirmed from. However, in water supply pipes, etc., there are many connecting parts between pipe joints and connecting pipes, and it is troublesome and not easy to check all joints with peep holes. Also, in small piping locations,
There is a possibility that the inside cannot be seen through the peep hole provided in the joint body.

In this way, when it is not possible to make a visual judgment, a method is adopted in which the worker senses the fluctuation of the reaction force applied to the connecting pipe from the pipe joint when inserting the connecting pipe into the joint body and makes a judgment. However, this method requires skill to make an accurate judgment. In addition, due to the tolerance of the joint body and the connecting pipe, the reaction force applied to the connecting pipe is not constant, and even a skilled person may not insert the connecting pipe to the predetermined position in the joint body, There is a risk of erroneously determining that it has been inserted.

The present invention solves the above-mentioned conventional problems, and an object thereof is to allow a continuation pipe to be easily inserted into a predetermined position of a joint body, and at the time of inserting the connecting pipe, to the predetermined position of the joint body. The object of the present invention is to provide a pipe joint that can accurately determine that the temperature has reached the limit.

(Means for Solving the Problems) A pipe joint of the present invention is an inner cylinder inserted into an end portion of a connecting pipe,
And a joint body having an outer cylinder externally fitted with a predetermined gap from the end portion of the connecting pipe and having a female screw portion formed on the inner peripheral surface of the distal end thereof, and the inner cylinder of the joint body Slit ring having a plurality of slits extending in the axial direction from the end surface into which the connecting pipe is inserted, with a predetermined gap so that the end of And between the slit ring and the inner cylinder of the joint body to prevent the diameter reduction of the slit ring, and on the end surface of the connecting pipe inserted between the slit ring and the inner cylinder. The slit ring is pressed down to a position where the diameter can be reduced, and a diameter reduction prevention ring is provided, whereby the above object can be achieved.

(Example) Hereinafter, the present invention will be described with reference to Examples.

The pipe joint of the present invention, as shown in FIG. 1, is a cylindrical joint body having an outer cylinder 11 and an inner cylinder 12 on one side in the axial direction.
It has a slit ring 20 fitted in an outer cylinder 11 of the joint body 10 and a tightening nut 30 screwed into the outer cylinder 11 of the joint body 10.

The joint body 10 is made of, for example, a metal having a high corrosion resistance such as stainless steel or a resin having a high rigidity, and is located on the side opposite to the side where the outer cylinder 11 and the inner cylinder 12 are arranged in the axial direction. A cylindrical connecting portion 13 is arranged in the portion. The inner diameter of the connecting portion 13 is slightly larger than the inner diameter of the inner cylinder 12, and the inner peripheral surface of the connecting portion 13 is continuous with the inner peripheral surface of the inner cylinder 12 via the tapered surface 14.

The outer cylinder 11 and the inner cylinder 12 of the joint body 10 have a gap sufficiently larger than the wall thickness of the connecting pipe 60, and the outer cylinder 11 is sufficiently longer than the inner cylinder 12. A female screw portion 11a is provided on the inner peripheral surface of the distal end portion of the outer cylinder 11, and a tightening nut is attached to the female screw portion 11a.
30 is screwed. The tightening nut 30 has a cylindrical shape in which a flange 31 having a hexagonal outer periphery is formed at the base end, and the inner peripheral surface of the tip portion is a tapered surface 32 whose diameter gradually increases as it becomes the tip. Has become.

An annular recessed groove 12a is formed on the outer peripheral surface near the tip of the inner cylinder 12, and a rubber seal member 50 is fitted into the recessed groove 12a. The seal member 50 has a V-shaped cross section so that the seal member 50 gradually becomes thinner toward the central portion in the axial direction of the outer peripheral surface.

A slit ring 20 is fitted between the outer cylinder 11 and the inner cylinder 12 of the joint body 10. The slit ring 20 is
The outer cylinder 11 and the inner cylinder 12 have a slight space inside the outer cylinder.
It is embedded in 11. As shown in FIG. 2, the slit ring 20 is in the shape of a cylinder having a flange portion 21 at the base end portion thereof. , Slits 22 are provided at equal intervals in the circumferential direction. Therefore, the slit ring
As shown in FIG. 2C, the diameter of 20 is reduced from the tip so that the peripheral edges of the slits 22 come into contact with each other. The outer peripheral surface of the tip portion of the slit ring 20 has a taper shape in which the diameter gradually decreases toward the tip. Further, the inner peripheral surface of the tip portion is provided with protrusions 23, 23, ...

The outer diameter of the slit ring 20 is in close contact with the inner peripheral surface of the base end of the outer cylinder 11 of the joint body 10 in the expanded state. It is inserted between the outer cylinder 11 and the slit ring 20 by being screw-fed to the outer cylinder 11 of 10. Between the inner peripheral surface of the slit ring 20 and the inner cylinder 11 of the joint body 10,
A gap is formed in which the connecting pipe 60 can be fitted. The protrusion 23 provided on the inner peripheral surface of the tip of the slit ring 20 is an inner cylinder.
It opposes the axial center part of the seal member 50 fitted in 12.

A diameter reduction prevention ring 40 is interposed in the axial center portion between the slit ring 20 and the inner cylinder 12 of the joint body 10. The diameter reduction prevention ring 40 has an annular shape with a short axial length, and its radial thickness is slightly larger than the thickness of the connecting pipe 60. And, the diameter reduction prevention ring 40 is
When the connecting pipe 60 is inserted between the outer cylinder 11 and the inner cylinder 12 of the joint body 10, the connecting pipe 60 comes into contact with the tip end surface of the connecting pipe 60 and moves in parallel in the gap between the outer cylinder 11 and the inner cylinder 12, It is pushed into the space inside the gap.

The pipe joint of the present invention having such a configuration is joined to the connecting pipe 60 as follows. First, the connecting pipe 60 is inserted into the tightening nut 30 loosely screwed into the outer cylinder 11 of the joint body 10. At this time, the slit ring 20 fitted in the outer cylinder 11 and the inner cylinder
A diameter reduction prevention ring 40 is interposed between the connecting pipe 60 and the inner ring 12, and the gap between the slit ring 20 and the inner cylinder 12 is slightly larger than the wall thickness of the connecting pipe 60. It is easily inserted into the gap.

When the connecting pipe 60 is inserted into the slit ring 20, the tip surface of the connecting pipe 60 receives a slight reaction force from the diameter reduction prevention ring 40, and the connection pipe 60 abuts the diameter reduction prevention ring 40. Is sensed. In this manner, with the connecting pipe 60 and the diameter reduction prevention ring 40 in contact with each other, the connecting pipe 60 is inserted into the inner cylinder 12 and the slit ring 20.
If the ring is further inserted into the gap between
Is pressed by the front end surface of the connecting pipe 60 and moves in parallel in the axial direction of the slit ring 20 into the inner part of the gap. As shown in FIG. 3, the diameter reduction prevention ring 40 is pushed out of the slit ring 20, and the outer cylinder 11 and the inner cylinder of the joint main body 10 are extruded.
It is pushed into the space inside the inner space of the gap with 12, and abuts against the end surface of the inner space. As a result, even if a force is applied in the axial direction to insert the connecting pipe 60 into the joint body 10, the connecting pipe 60 does not move, and the connecting pipe 60 has a gap between the outer cylinder 11 and the inner cylinder 12. The reaction force is received from the inner end surface of the inside of.

If this happens, the tightening nut 30 will rotate,
The tightening nut 30 is screw-fed into the outer cylinder 11 of the joint body 10. The tip of the tightening nut 30 is moved from the tapered surface of the outer circumference of the tip of the slit ring 20 to the slit ring.
20 Penetrates between the outer peripheral surface and the inner peripheral surface of the outer cylinder 11. As a result, the slit ring 20 is reduced in diameter at the tip of the tightening nut 30. At this time, as described above, the slit ring
There is no diameter reduction prevention ring 40 inside the slit 20, and the slit ring 20 is easily reduced in diameter from its tip. Then, as shown in FIG. 4, when the diameter of the slit ring 20 is reduced, the projection 23 provided on the inner peripheral surface of the leading end of the slit ring 20 is brought into contact with the outer peripheral surface of the connecting pipe 60.

After that, when the slit ring 20 is reduced in diameter by further screwing the tightening nut 30 into the outer cylinder 11, the connecting pipe 60 is pressed by the protrusion 23 of the slit ring 20 to be deformed, and the connecting pipe 60 is connected. The inner peripheral surface of the tube 60 is crimped to the seal member 50 fitted on the inner cylinder 12. As a result, the seal member 50 liquid-tightly seals between the connecting pipe 60 and the inner cylinder 12, and the connecting pipe 60 is firmly joined to the pipe joint.

In this way, when inserting the connecting pipe 60 into the joint body 10,
If the inserting direction of the connecting pipe 60 does not coincide with the axial center direction of the joint body 10, the compression preventing ring 40 does not reach the inner depth between the outer cylinder 11 and the inner cylinder 12, and the slit ring. Located within 20. Therefore, even if the tightening nut 30 is rotated, the diameter of the slit ring 20 cannot be reduced, and the worker cannot connect the connecting pipe.
It can be known that the tip of 60 has not reached the predetermined position in the joint body 10.

(Effect of the invention) As described above, in the pipe joint of the present invention, since the diameter reduction prevention ring is interposed between the inner cylinder of the joint body and the slit ring, the inner cylinder and the slit ring are interposed between the inner cylinder and the slit ring. The connecting pipe can be easily inserted. Then, when the connecting pipe reaches the predetermined position between the inner cylinder and the slit ring, the reaction force is surely applied from the diameter reduction prevention ring, so that the connecting pipe reaches the predetermined position of the joint body. It can be easily and surely recognized. At this time, since there is no diameter reduction prevention ring in the slit ring, the diameter of the slit ring can be easily reduced by the tightening nut, so that the connecting pipe and the joint body are firmly connected, and at the same time, the space between them is reduced. Securely sealed.

[Brief description of drawings]

1 is a partially cutaway side view of a pipe joint of the present invention, FIG. 2 (a) is a front view of a slit ring, FIG. 2 (b) is a side view thereof, and FIG. 2 (c) is a description of its operation. Front view for
FIG. 3 and FIG. 4 are explanatory views when connecting a connecting pipe to the pipe joint of the present invention. 10 …… Coupling body, 11 …… Outer cylinder, 12 …… Inner cylinder, 20 …… Slit ring, 22 …… Slit, 23 …… Protruding part, 30 …… Tightening nut, 40 …… Shrinkage prevention ring, 50 …… Seal member.

Claims (1)

[Claims] 1. An inner cylinder to be inserted into an end portion of a connecting pipe, and an outer shell having a female screw portion formed on an inner peripheral surface of a distal end portion of the connecting pipe to be fitted outside with a predetermined gap. The joint body having a tube and the inner tube of the joint body have a cylindrical shape and are fitted in the outer tube with a predetermined gap so that an end portion of the connection tube can be inserted. A slit ring having a plurality of slits extending in the axial direction from the end surface into which the slit is inserted, and the slit ring is interposed between the slit ring and the inner cylinder of the joint body to prevent the slit ring from being reduced in diameter. A pipe fitting comprising: a diameter reduction prevention ring that is pushed to a position where the slit ring can be reduced in diameter at an end surface of a connecting pipe inserted between the ring and the inner cylinder.