JPH03288092A - Tube joint - Google Patents

Abstract

PURPOSE:To obtain a tube joint excellent in work performance and prevent the end face of a tube body and the inner peripheral surface of a joint body positively from corrosion by providing the tube joint with a cylindrical joint body between tube bodies to be connected, a sleeve, elastic seal members, slip-off stopper members, and press- fitting members. CONSTITUTION:A tube joint is provided with a cylindrical joint body 20 to be inserted into both end parts of tube bodies 10, 10, and a cylindrical sleeve 30 provided inside the joint body 20. A pair of elastic seal members 40, 40 are fitted at the periphery of the insert part 31 of the sleeve 30, holding a supporting part 32 in between. The end part periphery of each tube body 10 is fitted with an elastic seal member 50, a slip-off stopper member 60, and a box nut, a press-fitting member for moving the slip-off stopper 60 toward the tip side of the tube body 10 so as to press-fit the elastic member 50 into each holding part 21 of the joint body 20. The space between the end part inner peripheral surface of the tube body 10 and the sleeve 30 is thus sealed by the elastic seal member 50, so that liquid leak is prevented, and also the end face of the tube body 10 is positively prevented from corrosion. Connecting work between the joint and the tube body is simplified remarkably because of slip-off prevention by the slip-off stopper member.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pipe joint used to connect a plurality of pipe bodies to each other, to connect a pipe body to equipment, and the like.

(Prior Art) Plug-in type pipe joints are used as pipe joints for interconnecting inner resin-coated pipes in which the inner peripheral surfaces of metal pipes are coated with a synthetic resin layer. 7435
It is disclosed in the publication No.

The pipe joint has a cylindrical joint body into which the end of the pipe body to be connected is inserted, and a threaded groove is provided on the outer peripheral surface of the end, and the joint body is externally screwed into the thread groove of the joint body. It is equipped with a bag nut. The end of the tube connected to the pipe joint is covered with a sealing cap, and an annular packing holder is caulked into a circumferential groove provided on the outer peripheral surface of the end.

When connecting the pipe body to the pipe joint, a gasket is externally fitted on the part of the pipe body on the distal side of the seal presser, and a cap nut is externally fitted on the proximal side of the seal presser, The end of the tube is inserted into the joint body, and the cap nut is screwed into the joint body. As a result, the packing retainer is pushed into the end of the joint body by the cap nut, and the pipe body is prevented from coming off from the joint body. Also, by compressing the packing inside the end of the joint body with the packing presser, a seal is created between the outer peripheral surface of the end of the pipe inserted into the joint body and the inner peripheral surface of the end of the joint body. .

(Problems to be Solved by the Invention) In such conventional plug-in type pipe joints, since the ends of the pipe bodies to be connected are covered with caps, the end faces of the pipe bodies are protected from corrosion. However, since the inner circumferential surface of the joint body comes into contact with the liquid flowing through the tube, there is a risk that the inner circumferential surface of the joint body will be corroded by the liquid. Furthermore, although the end surface of the tube body can be protected from corrosion, the end must be covered with a cap.

Furthermore, the end of the tube must be caulked to secure the seal holder, which poses a problem of extremely poor workability.

The present invention solves the above-mentioned conventional problems, and its purpose is to reliably protect the inner peripheral surface of the joint body as well as the end face of the pipe body, and to attach a cap to the end of the pipe body. It is an object of the present invention to provide a pipe joint which is excellent in workability since it is not necessary to perform caulking or the like on the end of the pipe body.

(Means for Solving the Problems) The pipe joint of the present invention includes a cylindrical joint body into which a pipe body to be connected is inserted, and a pipe joint body inserted into the joint body so as to be inserted into the pipe body. A sleeve is installed within the joint body with a space between the sleeve and the inner circumferential surface of the joint body, and an elastic seal is fitted onto the sleeve so as to be pressed against the inner circumferential surface of the tube into which the sleeve is inserted. and a retainer arranged to be inserted into the joint body when the pipe body is inserted into the joint body, and whose inner peripheral surface can be locked to the pipe body. and a press-fitting member that is fitted onto the end of the joint body so that the retaining member is press-fitted into the end of the joint body to reduce its diameter, thereby achieving the above object. achieved.

(Example) The present invention will be described below with reference to Examples.

The pipe fitting of the present invention is used to interconnect tubes 10 and 10, as shown in FIG.

Each tube body 10 is an inner resin-coated tube in which the inner circumferential surface of a metal tube 11 is coated with a synthetic resin layer 12, and its ends are not processed at all, such as threading.

The pipe joint of the present invention that interconnects the pipe bodies 10 and 10 includes a cylindrical joint body 20 into which the pipe bodies 10 and 10 are inserted at both ends, and a cylindrical joint body provided inside the joint body 20. It has a sleeve 30.

The joint body 20 is made of metal and includes holding parts 21 provided at each end, and a connecting part 22 that connects the holding parts 21. A tapered male screw portion 21a is provided on the outer circumferential surface of the end portion of each holding portion 21, and the outer diameter of the holding portion 21 gradually decreases toward the tip. Each holding part 21
The inner circumferential surface of the end portion is a tapered guide portion 21b whose inner diameter gradually decreases from the tip toward the innermost side.

The inner diameter at the inner end of the guide portion 21b is the same as that of the tube body 10.
It is slightly larger than the outer diameter of. A concave groove 21c that continues in the circumferential direction is provided on the inner peripheral surface of the guide portion 21b on the inner back side. A protrusion 22 a that protrudes inward is provided on the inner circumferential surface of the axially central portion of the connecting portion 22 sandwiched between the respective holding portions 21 so as to have an inner diameter that is approximately the same as the inner diameter of the tubular body 10 .

The sleeve 30 provided inside the joint body 20 is made of synthetic resin, and includes a cylindrical insertion part 31 that is concentric with each holding part 21 of the joint body 20, and an axis of the insertion part 31. It has a support portion 32 provided at the center in the direction so as to extend outward.

The insertion portion 31 has an outer diameter smaller than the inner diameter of the tubular body 10, and each end portion is located in the middle of each holding portion 21 in the joint body 20 in the axial direction.

The support portion 32 extending outward from the axial middle of the insertion portion 31 is arranged along the surface of the protrusion 22a provided on the connecting portion 22 of the joint body 20 so as to cover the protrusion 22a. At the same time, each holding part 2 in the joint body 20
It fits into the groove 21c of No. 1.

A pair of elastic seal members 40 and 40 made of rubber or the like are fitted onto the insertion portion 31 of the sleeve 30 with the support portion 32 in between. Each elastic seal member 40
The cylindrical portion 41 is in pressure contact with the entire outer peripheral surface of the insertion portion 31, and the cylindrical portion 41 is located on the support portion 32 side of the sleeve 30.
It has a flange portion 42 provided at the end of the flange portion 42 . The outer diameter of the cylindrical portion 41 is larger than the inner diameter of the tubular body 10 except for its tip. The flange portion 42 is attached to the joint body 20
The support part 32 of the sleeve 30 that covers the protruding part 22a of the connecting part 22 is in contact with the support part 32 of the sleeve 30.

An end portion of each tube body 10 is inserted into each holding portion 21 in the joint body 20. At the end of each tube 10, an annular elastic seal member 50 made of rubber or the like and an annular retaining member 60 made of metal are arranged in parallel in the axial direction. It is fitted externally. Each stopper member 60 is larger than each elastic seal member 50 than the tube body l.
It is located on the tip side of O.

Each elastic seal member 50 has a diameter that gradually decreases as the outer circumferential surface approaches the distal end of the tubular body IO so that the elastic seal member 50 can be press-fitted into the tapered guide portion 21b provided on the inner circumferential surface of the end portion of the holding portion 21. It has a wedge-shaped cross section. Elastic seal member 5
The axial length of 0 is approximately the same as the axial length of the tapered guide portion 21b. As shown in FIG. 2, each stopper member 60 has a tapered guide portion 21b on the outer circumferential surface of one end located on the tip side of the pipe body 10 and similar to the tapered guide portion 21b in each holding portion 21 of the joint body 20. A first tapered portion 61 that is in an inclined state is connected to the side opposite to the tip side of the tube body 10 of the first tapered portion 61, and is inclined in the opposite direction to the first tapered portion 61. It has a second tapered portion 62. The inner circumferential surface of the retaining member 60 is a locking circumferential surface 63 having a sawtooth cross section in which peaks and valleys having a triangular cross section are alternately continued in the axial direction. The inner diameter of the locking peripheral surface 63 is the same as that of the tube body 10.
It is slightly larger than the outer diameter of.

In each method, the stopper member 60 is moved toward the distal end side of the tube body 10, and each elastic seal member 50 is attached to the joint body 2.
A cap nut 70, which is a press-fitting member to be press-fitted into the tapered guide portion 21b of each holding portion 21 of 0, is externally fitted. Each cap nut 70 is configured such that each holding portion 21 of the joint body 20 is inserted through an opening on the tip side of each tube body 1O. The inner peripheral surface of the cap nut 70 is provided with a tapered female threaded portion 71 that is screwed into the tapered male threaded portion 21a of each holding portion 21 of the joint body 20. In addition, the end of each cap nut 70 on the side opposite to the opening into which each holding portion 21 is inserted in the joint body 20 is
It is fitted onto the outside of the tube 10 with a gap, and the inner circumferential surface on the tip side of the tube 10 is in contact with the outer circumferential surface of the tip of the second tapered portion 62 of the stopper member 60. A tapered portion 72 is formed.

A pressing surface 73 is connected to the tapered portion 72 and comes into contact with the end surface of the second tapered portion 62 side of the retaining member 60 .

In the pipe joint of the present invention having such a configuration, each pipe body 10 is connected in the following manner.

At the end of each tube body 10 to be connected, a cap nut 70, a retaining member 60, and an elastic seal member 50 are attached from the end surface side.
are fitted externally in order. At this time, the female threaded portion 71 of the cap nut 70 is directed toward the distal end of the tubular body 10 , and the first tapered portion 61 of the retaining member 60 is positioned toward the distal end of the tubular body 10 . Further, the end portion of the elastic seal member 50 having a smaller diameter on the outer circumferential surface is located on the distal end side of the tube body 10 .

In this state, the end of each tube body 10 is inserted into each holding part 21 of the joint body 20. By this company, each end of the insertion part 31 of the sleeve 30 is inserted into the end 71 of each tube 10. As a result, the inner circumferential surface of the end of each tube body 10 is pressed against the outer surface of the cylindrical portion 41 of each elastic seal member 40 fitted onto the insertion portion 31 of the sleeve 30 . When each tube 1O is inserted into each holding portion 21 of the joint body 20 until the end surface of the tube 10 comes into contact with the flange portion 42 of the elastic seal member 40, the end of each tube 10 is inserted outwardly. The female threaded portion 71 of the fitted cap nut 70 is screwed into the male threaded portion 21a of each holding portion 21 of the joint body 20.

As the cap nut 70 is screwed in, the retaining member 60 fitted onto the end of each tubular body 1O is caused to loosen its second tapered portion 6.
2 is in contact with the tapered portion 72 of the cap nut 70,
The pressing surface 73 of the bag nut 70 is press-fitted into the tapered guide portion 21b of each holding portion 21 of the joint body 20. As a result, each elastic seal member 50 fitted onto the end of each tube body 10 is also pushed into each guide portion 21b,
It is compressed between the outer circumferential surface of the end of the tube body 10. Further, the tip end of the elastic seal member 50 is moved further inside the guide portion 21b, and the outer circumferential surface of the tip end of each elastic seal 60 is fitted into the groove 21c in each holding portion 21 of the joint body 20. The support part 32 of the sleeve 30 is pressed against the support part 32 of the sleeve 30.

Furthermore, when the cap nut 70 is screwed in, the retaining member 60
By reducing the diameter of the first tapered portion 61 of the first
A locking circumferential surface 63 having a saw-toothed end surface located on the inner surface side of the taper 61 bites into the outer circumferential surface of the end portion of the tubular body IO.

At this time, the second tapered portion 62 of the retaining member 60 is
Since the end portion is supported by the tapered portion 72 of the bag hollow 70, the diameter of the entire second tapered portion 62 is reduced, and the locking peripheral surface 63 is located on the inner side of the second tapered portion 62. It also bites into the outer peripheral surface of the end face of the tube body 10. Further, when the cap nut 70 is screwed in, the end surface of the tube body 10 is pressed against the flange portion 42 of the elastic seal portion 40.

In the pipe joint of the present invention in which the respective pipe bodies 10 are connected in this way, there is a gap between the inner peripheral surface of the end of the pipe body 10 and the insertion part 31 of the sleeve 30, and between the end face of the pipe body 10 and the sleeve 30.
and the support portion 32 are sealed with elastic seal members 40, respectively. Therefore, there is no possibility that the liquid flowing through the tube body 10 leaks to the outer surface of the insertion portion 31 of the sleeve 30. Therefore, the end surface of the metal tube 11 that is not coated with the synthetic resin layer in the tube body 10 is protected from corrosion, and the inner circumferential surface of the joint body 20 is also protected from corrosion. In addition, even if liquid leaks to the outer surface of the insertion part 31, the joint body 2
0 is covered with a sleeve 30 on the inner circumferential surface except for the guide portion 21b, and is further provided with an elastic seal compressed between the outer circumferential surface of the end of the pipe body 10 and the inner circumferential surface of the holding portion 21 of the joint body 20. Since the member 50 prevents liquid from coming into contact with the guide portion 21b, the inner circumferential surface of the joint body 20 is reliably protected from corrosion.

The retaining member 50 press-fitted into the guide portion 21b of the joint body 20 with the cap nut 70 is attached to the holding portion 21 of the joint body 20.
Even when a pull-out force from the joint body 20 is applied to the pipe body 10 because it bites into the outer peripheral surface of the end of the pipe body 10 inserted therein, there is no risk that the pipe body 10 and the joint body 20 will move. . Therefore, the sealing performance is maintained stably even after construction.

The pipe joint of the present invention is not limited to the above-described embodiment, and may have a configuration as shown in FIG. 3, for example. In this embodiment, the sleeve 30 is such that the support portion 32 that supports the insertion portion 31 covers only the protruding portion 22a of the connecting portion 22 in the joint body 20. No groove is provided on the inner circumferential surface of each holding portion 21 in the joint body 20. Even when such a sleeve 30 is used, since the elastic seal member 40 seals between the tube body 10 and the sleeve 30, the inside of the joint body 20 is not affected by the liquid flowing inside the tube body 10. The surrounding surface is protected against corrosion.

Further, the retaining member 60 is provided with a tapered portion 64 corresponding to the guide portion 21 in each connecting portion 2 of the joint body 20 on the outer circumferential surface of one end portion. The retaining member 60 of the cap nut 70 is pressed by a pressing surface 74 at an end located on the opposite side of the opening into which each holding portion of the joint body 20 is inserted. Then, by press-fitting the retaining member 60 into the guide portion 21b and reducing its diameter, the locking circumferential surface 63 having a sawtooth cross section formed on the inner circumferential surface of the retaining member 60 is brought into contact with the outer circumferential surface of the end portion of the tubular body IO. The tube body 10 is prevented from coming off.

Moreover, as shown in FIG. 1, if the protruding part 22a of the connecting part 22 has a shape whose width becomes narrower in two steps, when the tube body 10 is pushed into the holding part 2 and the cap nut 70 is tightened, , it is possible to prevent the distal end of the tube body 10 from being strongly pressed against the connecting portion 22 and damaging the support portion 32 of the sleeve 30. Furthermore, by appropriately selecting the relationship between the width of this stepped portion and the thickness of the support portion 32 and the thickness of the flange portion 42 of the elastic seal member 40, appropriate sealing performance can be provided.

(Effects of the Invention) As described above, in the pipe joint of the present invention, the elastic seal member is fitted onto the sleeve inserted into the inside of the pipe body inserted into the joint body, and the elastic seal member secures the pipe body. Since a seal is formed between the inner circumferential surface of the end of the tube and the sleeve, the liquid flowing back inside the tube is prevented from leaking to the outside of the joint, and the end surface of the tube is reliably protected from corrosion. Therefore, there is no need to attach a cap to the end of the tube. Further, since the elastic seal member seals between the tube body and the sleeve, the inner surface of the joint body is also protected from corrosion.

Furthermore, since the tube inserted into the fitting body is prevented from coming off by the retaining member that is press-fitted into the end of the fitting body, there is no need to process the end of the tube to prevent it from coming off. This greatly simplifies the connection work between the joint and the pipe body.

4. Important Words Figure 1 is a partially cutaway side view showing an example of the pipe joint of the present invention.
FIG. 2 is an enlarged sectional view of the retaining member, and FIG. 3 is a partially cutaway side view showing another embodiment of the pipe joint of the present invention.

DESCRIPTION OF SYMBOLS 10... Pipe body, 20... Joint main body, 30... Sleeve, 40... Elastic sealing member, 60... Removal prevention member, 70... Press-fitting member.

that's all

Claims (1)

[Claims] 1. A cylindrical joint body into which a pipe to be connected is inserted, and an inner part of the joint body inserted into the joint body so as to be inserted into the inside of the pipe inserted into the joint body. a sleeve attached at a distance from the circumferential surface; an elastic sealing member fitted onto the sleeve so as to be pressed against the inner circumferential surface of the tube into which the sleeve is inserted; A retaining member arranged to be inserted into the joint body when inserted into the joint body, and whose inner peripheral surface can be locked to the pipe body; and the retaining member. A pipe joint comprising: a press-fitting member that is fitted onto an end of the joint body so as to be press-fitted into the end of the joint body to reduce the diameter thereof.