JP3000009U - Joint - Google Patents

Abstract

(57) [Abstract] [Purpose] Resin pipes, especially fluororesin pipes, or pipes and other equipment are connected only by joints without using means such as adhesives or heat fusion. A nut-shaped fastener having an outer annular portion and an inner annular portion, and an annular member having an inner peripheral surface with a stopper portion and a rising portion inserted between the outer annular portion and the inner annular portion of the fastener. The joint body, and an annular body that is interposed between the stopper portion and the end portion of the inner annular portion and crimps the folded portion of the resin pipe to the stopper portion. The joint is a threaded portion formed on the inner peripheral surface to be screwed with the outer peripheral surface of the rising portion, and the joint body is formed with an annular groove at a portion of the stopper portion facing the folded top of the resin pipe.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention mainly relates to a joint used in a piping system for transferring a high-temperature and high-pressure deleterious fluid in so-called high-tech fields such as semiconductor production.

[0002]

[Prior art and its problems]

 As a joint mechanism for plastic pipes (including tubes), various tape-tight structures such as tape-tight taper screws and ferrules are known. However, in a fluororesin such as TFE (polytetrafluoroethylene), PFA (copolymer of polytetrafluoroethylene and perfluoroalkyl vinyl ether), FEP (copolymer of polytetrafluoropropylene), etc. Due to its characteristics, the liquid used is often a high-temperature, high-pressure deleterious substance, etc., and fluid leakage occurs due to factors such as repeated expansion and contraction due to thermal cycles and generation of creep.

This is because a minute gap is generated mainly in the joint portion due to the above factors, and it is extremely difficult to prevent this. Therefore, the conventional fittings are forced to be used under the condition that the fluid temperature is 120 ° C and the pressure is about 2 kg / c or less.

[0004]

[Means for Solving the Problems]

 In this invention, a joint is inserted between a nut-shaped fastener having an outer annular portion and an inner annular portion, a stopper portion on an inner peripheral surface, and the outer annular portion and the inner annular portion of the fastener. An annular joint body having a rising portion, and an annular body interposed between the stopper portion and the end portion of the inner annular portion for crimping the folded portion of the resin pipe against the stopper portion. A threaded portion is formed on the inner peripheral surface of the outer annular portion of the tool that is screwed onto the outer peripheral surface of the rising portion, and the joint body is fitted with an O-ring at the portion of the stopper portion facing the folded top of the resin pipe. It is intended to solve the above-mentioned conventional problems by forming an annular groove portion.

Further, in the present invention, the stopper portion is provided on the inner peripheral surface of the joint body so as to project in a semi-radial direction, and a resin contacting the opening edge of the annular groove portion formed in the annular stopper portion is provided. An engaging portion for the pipe is formed, and the engaging portion is formed into a square shape or other cross-sectional shape that can be bitten into the surface of the resin pipe by being pressed.

[0006]

[Action]

 In the joint according to the present invention, the folded-back portion of the end of the resin pipe is crimped and pinched by the tip of the annular body and the annular groove of the stopper portion by screwing the fastener and the rising portion of the joint body. And the resin pipe are in complete contact. That is, the engagement formed on the edge of the annular groove firmly bites into the resin pipe surface to improve the adhesion, and when the O-ring is installed in the annular groove, the adhesion is improved. Therefore, even if the temperature and pressure conditions of the fluid in conventional joints are significantly higher than the allowable range, problems such as leakage do not occur and extremely reliable resin pipes are used. A joint can be realized.

[0007]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. 1 and 2 are views showing an embodiment of the present invention. In FIG. 1, 1 is a fastener made of a cylindrical resin or metal material having an outer annular portion 1a and an inner annular portion 1b, and a screw portion 1c is formed on the inner peripheral surface of the outer annular portion 1a. . Reference numeral 2 denotes a tubular joint body that is screwed into the fastener, and is made of a resin or a metal material like the fastener. The joint body 2 is integrally formed with a ring-shaped rising portion 2a that is screwed with the screw portion 1c and a stopper portion 7. The stopper portion 7 is formed so as to project in an annular shape in the radial direction on the inner peripheral surface of the joint body 2, and is in contact with the top portion 4b of the folded portion 4a (reversed portion) of the resin pipe 4. Reference numeral 7a is an annular groove portion formed in a portion of the stopper portion 7 facing the top portion 4b of the resin pipe 4, and reference numeral 6 is an O-ring made of rubber material mounted in the annular groove portion 7a. The pipe 4 is made of resin material such as fluorine, polybutene, PFA, polypropylene, nylon.

Reference numeral 5 denotes an annular body, which is interposed between the end portion of the inner annular portion 1b of the fastener 1 and the stopper portion 7, and has a slightly tapered tip portion 5a, at which the folded portion of the resin pipe 4 ( The top portion 4b of the inverted portion) is pressed in the direction of the annular groove portion 7a. Reference numeral 3 is a pump in which the joint body 2 is screwed.

FIG. 2 is a diagram showing a related configuration of the folded back top portion 4b of the resin pipe 4 and the annular groove portion 7a. 7b is a locking portion formed by a corner portion formed at the opening end edge of the annular groove portion 7a. is there. In this embodiment, the locking portion 7b is formed at an angle of about 90 degrees, but this angle may be an obtuse angle or an acute angle. Further, the shape of the locking portion does not necessarily have to be a corner portion as long as it can be properly engaged with the surface of the resin pipe.

Next, the operation will be described together with the procedure for assembling the joint according to this embodiment. First, the fastener 1 is passed through a resin pipe, and then the pipe tip is folded back with the annular body 5 fitted in the end portion of the resin pipe 4. As a result, the folded portion 4a of the pipe 4 is brought into close contact with the outer peripheral surface of the annular body 5, and the top portion 4b of the folded portion 4a and the tip of the annular body 5 are also brought into close contact with each other. Next, the joint body 2 in which the O-ring 6 is attached to the annular groove portion 7a is fitted into the folded portion 4a (reversal portion) of the pipe 4, and the fastener 1 is screwed into the joint body 2. The fastener 1 descends as the screwing progresses. As the fastener 1 descends, the inner annular portion 1b enters into the gap between the pipe body and the rising portion 2a of the joint body 2, abuts against the rear end of the annular body 5 and presses it. Upon completion of fastening of the fastener 1, the tip portion 5a of the annular body 5 crimps and clamps the top portion 4b with the locking portion 7b of the annular groove portion 7a to completely shut off the leakage of fluid from the inside of the pipe 4.

In this state, as shown in FIG. 2, the folded top portion 4b of the pipe 4 is pressed by the tip of the annular body 5 and protrudes into the annular groove portion 7a to be crimped to the O-ring 6, while the engaging portions of the annular groove portion 7a. The stoppers 7b, 7b are in close contact with the surface of the pipe 4 while biting into the surface. Therefore, leakage of fluid between the pipe 4 and the joint body 2 is prevented by the first locking portion, the O-ring portion, and the second locking portion in a double or triple manner. In this embodiment, the O-ring 6 is mounted in the annular groove portion 7a, but the case where the O-ring 6 is not mounted is also included in the scope of right.

The tip of the resin pipe 4 is bent using a dedicated jig. However, if the thickness of the pipe is large and it is difficult to fold it, a deep circumferential cut is made on the end face of the pipe to form a double layer. Alternatively, it can be easily folded back by forming a plurality of layers.

FIG. 3 is a diagram showing another embodiment of the present invention. In this embodiment, the tip of the pipe 4 is expanded outwardly at a substantially right angle, but the other construction is exactly the same as that of the previous embodiment. When the folding back is set to 90 degrees in this way, the inverted portion (illustrated as the folding back portion 4a) shown in FIG. 1 disappears, so that it is impossible to adhere it to the rising portion 2a. Blocking against fluid leakage is perfect with multiple locking parts, O-rings, etc. Spreading the tip of the pipe is still done with a special jig, but it is easier than when it is completely inverted.

In each of the above-described embodiments, the connection of the resin pipe and the other equipment such as the pump by the joint has been described. For example, in FIG. 1, the joint main body is formed vertically symmetrical, that is, the joint main body. If a pair of upright portions are provided symmetrically about the stopper portion in the vertical direction and the annular groove portions are provided on both front and back surfaces of the stopper portion, the pipes can be connected in both directions of the joint body. Of course, such a configuration also falls within the scope of the present invention.

[Effect of device]

 The present invention completely prevents leakage due to the creep phenomenon, which is a major drawback of conventional joints, by means of the above-described constitutional effects, and particularly under high temperature and high pressure environments where no convenient and effective connecting means have been found. It is very easy to connect the fluororesin pipe that can be used in.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment according to the present invention.

FIG. 2 is an enlarged view of an end face of a cut part of a main part according to the embodiment.

FIG. 3 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fastener 1a Outer annular part 1b Inner annular part 1c Screw part 2 Joint body 2a Rising part 3 Pump 4 Pipe 4a Folding part (reversal part) 4b Top part 5 Annular body 6 O-ring 7 Stopper part 7a Annular groove part 7b Locking part

Claims (3)

[Scope of utility model registration request] 1. A nut-shaped fastener having an outer annular portion and an inner annular portion, and a stopper portion and a rising portion inserted between the outer annular portion and the inner annular portion of the fastener on an inner peripheral surface. An annular joint body, and an annular body that is interposed between the stopper portion and the end portion of the inner annular portion to press the folded portion of the resin pipe against the stopper portion, and the fastener is an outer annular portion. A threaded portion that is screwed onto the outer peripheral surface of the rising portion is formed on the inner peripheral surface of the joint body, and the joint body is formed with an annular groove portion at a portion of the stopper portion that faces the folded top of the resin pipe. . 2. The resin according to claim 1, wherein the stopper portion is provided so as to project in a radial direction on an inner peripheral surface of the joint body, and abuts on an opening end edge of the annular groove portion formed in the annular stopper portion. A joint characterized in that an O-ring is mounted in the annular groove while forming a locking portion to the pipe. 3. The joint according to claim 2, wherein the engaging portion is a corner portion.