JPH0435663Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a pipe joint that prevents pipes from being pulled out by mechanical connection means without cutting threads on gas pipes or water pipes.

[Conventional technology]

Conventionally, for example, in Japanese Patent Application Laid-open No. 134225/1983, No.
As shown in Fig. 7, a pipe joint is known that has a pipe pull-out stopper in which a plurality of rotatable fitting members such as steel balls are arranged on the circumference of the pipe on the tapered inner surface of the push ring and held by an elastic ring. ing. Another conventional example is Utility Model Application No. 56-55169, in which downward inverted conical protrusions are provided at several locations on the bottom surface so that the tips of the protrusions are along the circumferential surface of the tube, and the outer circumferential side is aligned with the axis of the tube. In other words, scooping members having a conical surface annularly around the tube are arranged at four locations on the circumference of the tube, and the inner surface is in contact with the outer peripheral surface of the tube and the outer surface is in contact with the tapered inner surface of the push ring. 2. Description of the Related Art A pipe joint is known that has a pipe stopper that is connected and held in an annular manner by an elastic ring.

[Problem that the idea aims to solve]

Of the above, the former pipe removal stopper is pressed by the tapered inner surface formed on the inner surface of the push ring by screwing and tightening the push ring to the joint body, and the steel ball is pressed between the outer circumferential surface of the pipe and the tapered inner surface. While rotating between the pipes, it bites deeply into the outer circumferential surface of the pipe and prevents the pipe from being pulled out after being connected. However, when connecting externally resin-coated steel pipes, when the joint body and press ring are screwed together and tightened during connection, the steel ball of the biting member rotates around the pipe, so the resin layer of the externally resin-coated steel pipe is twisted into a spiral shape. hurt to. For this reason, it was not preferable in terms of corrosion protection of steel pipes. In addition, in terms of preventing the steel pipe from being pulled out, when a pull-out force is applied to the steel pipe, the steel ball rotates between the tapered inner surface of the press ring and the outer circumferential surface of the pipe, so the length of the steel pipe to be pulled out is large, and the joint body If a sufficient insertion length is not ensured before inserting the steel pipe into the pipe, only a small pull-out prevention force will be obtained. Therefore, the shape of the joint body had to be made large, and it was difficult to obtain a large pull-out prevention force with a small pull-out length. The latter pipe removal stopper has a biting member held in an annular shape by an elastic ring, but since the biting member has a conical surface annularly around the pipe, the biting member is held by the tapered inner surface of the press ring. The force on the outer circumferential surface is dispersed, and since the tips of the protrusions on the bottom of the biting member are arranged along the outer circumferential surface of the tube, several protrusions press against the tube at the same time, and the number of protrusions is equal to the number of protrusions. The force of biting into the outer surface is dispersed. Therefore, the initial biting force when tightening the press ring and the biting force when a pulling force is applied to the tube after connection are small, and a large force for preventing the tube from being pulled out cannot be obtained. Furthermore, since the protrusions are individually protruding in several places, when a pull-out force is applied to the tube, the protrusions that have bitten into the tube are bent by the pull-out force of the tube, and the protrusions come off from the biting parts, causing the tube to collapse. There is a problem in that it slides on the outer surface and cannot provide enough force to prevent large pipes from being pulled out.

[Problem that the idea aims to solve]

The gist of the present invention is to insert one end of the pipe into the enlarged diameter part of the joint body, insert a packing between the inner surface of the enlarged diameter part and the outer surface of the pipe, and insert a ring placed on the end side of the packing. At the same time, a press ring is provided with a tapered inner surface that narrows toward the end, and a pipe pull-out stopper is installed between the tapered inner surface and the outer surface of the pipe. In a pipe joint that tightens a pipe by tightening the pipe toward the joint body, the retainer has an annular blade portion on the inner side that protrudes toward the inner surface of the pipe, and the tips of the blades are in the same plane. The outer surface side is characterized by comprising a scooping member having a smooth conical surface with respect to the normal line on the pipe circumference, and an elastic ring that connects and holds a plurality of the scooping members arranged around the outer circumference of the pipe in an annular shape. It is a pipe joint.

[Effect]

The contact surface of the biting member against the pipe outer circumferential surface is formed by an annular blade whose tips are flush with each other, so the part of the annular blade of one biting member that contacts the pipe outer circumferential surface is the same as that of the pipe. Since there are two points that are in contact with each other in the axial direction, the initial biting force of the blade when tightening the press ring is large, and the initial biting is reliably performed. In addition, since biting is performed by the annular blade sequentially from this initial biting part as a base, a large biting can be obtained.Furthermore, since the biting part of the biting member is annular, the biting part is stably pressed and strong biting is achieved. be exposed. Moreover, since the outer surface has a smooth conical surface with respect to the normal line on the tube circumference, it slides on the tapered inner surface of the press ring and digs deeply into the tube outer circumferential surface at a certain position. Therefore, there is no biting damage anywhere other than the biting part on the outer circumferential surface of the tube, and the biting occurs at the same biting position from the beginning to the end, so the length of the tube inserted into the joint body can be shortened, and the joint body can be formed compactly and very easily. It is possible to obtain a large tube pull-out prevention force.

【Example】

Fig. 1 is a partial sectional view of a pipe joint according to an embodiment of the present invention, Fig. 2 is a side view of the biting member shown in Fig. 1, and Fig. 3 is an enlarged sectional view of the main part showing the state after the press ring is tightened. be. The pipe removal stopper 1 includes a plurality of recess members 2 arranged at equal intervals on the circumference and connected and held in an annular shape by an elastic ring 3 so that the pipe removal stopper 1 can be inserted into the outer periphery of the connecting pipe 8. The inner surface of this biting member 2 is provided with an annular blade portion 21 whose protruding blade tips are flush with each other toward the inner surface of the tube, and the outer surface has a conical surface 22 that is smooth with respect to the normal line on the tube circumference. It is provided. In Fig. 1, 4 is the joint body, and the end enlarged diameter part 4
A flange 42 is formed on the outer surface of the end portion 4.
On the inner surface of 1, there is a packing 6 with a wedge-shaped cross section from the back side,
A retainer 7 and the pipe removal stopper 1 described above are attached. A flange 52 corresponding to the flange 42 of the joint body 4 is provided on the outer peripheral surface of the push ring 5, and a flange 52 is provided on the outer peripheral surface of the push ring 5.
6,57. An end 51 that comes into contact with the retainer 7 is provided at the center end of the push ring 5, and the inner surface has a tapered inner surface 5 that narrows toward the end.
3 is provided. The outer surface of the biting member 2 of the retainer 1 and the outer peripheral surface of the elastic ring 3 are in contact with the tapered inner surface 53 of the push ring with the joint body 4 and the push ring 5 being hand-tightened. FIG. 3 shows an enlarged view after tightening the fasteners 56 and 57 with a wrench or the like from the hand-tight state shown in FIG. sealed from the fluid flowing within it. On the other hand, since the annular blade part 21 formed on the inner surface of the biting member 2 is formed so that the tips of the blades are on the same plane, the blade part 21 bites into the tube 8 sequentially from two places on the outer surface in the axial direction thereof. The initial biting force exerted on the tube is large because there are two places per biting member, and biting is easily performed on all the annular blades in order from this initial biting part as a starting point. The elastic ring 3 that connects and holds the biting member 2 stably holds the biting member 2 by contacting the outer surface of the tube 8 and the tapered inner surface 53 of the press ring, and further prevents corrosive fluid from entering the biting part from the inner and outer surfaces of the tube. To prevent corrosion of the biting part and the biting member 2 by preventing intrusion.
Furthermore, since the inner surface of the biting member 2 is an annular blade part 21, biting is performed with a large biting force until the end at the biting part position at the initial stage of tightening the press ring, and a large force for preventing the pipe from being pulled out can be obtained. Next, FIG. 4 shows the state of another embodiment after tightening the press ring, in which a parallel inner surface 54 with a smaller diameter is provided on the end side of the tapered inner surface of the press ring, and a parallel inner surface 54 with a smaller diameter is provided on the tapered inner surface 53 on the large diameter side of the elastic ring. An example is shown in which the side is formed so as to contact the entrance of the parallel inner surface 54. 56 is push ring 5
81 is a resin coating layer provided on the inner surface of the tube 8.
The outer resin coating layer is shown. FIG. 5 shows a state in which a pull-out force is applied to the tube 8 from the state shown in FIG.
The biting member 2 moves toward the end of the pipe 8 and bites deeply into the tube 8, exhibiting an even stronger pulling-out prevention force. In this state, the small-diameter side of the elastic ring 3 is inserted into the parallel inner surface 54 formed at the small-diameter end of the tapered inner surface 53, and the recessed member 2 is engaged with the stepped portion 55. When the biting member 2 moves to the stepped portion 55, biting into the tube 8 is stopped, and the biting depth into the outer surface of the tube 8 is kept constant. The inner edge of the biting member 2 is annular as in the previous embodiment, so it can easily bite into the tube, and the compression of the inner and outer surfaces of the elastic ring 3 allows the biting member to stably contact the outer circumference of the tube. Since they are in contact with each other and bite into each other, there is no chipping or bending of the blade part 21 due to the pipe being pulled out, and there is no slipping on the outer circumferential surface of the pipe. According to the experimental results, when compared with conventional biting members using steel balls under the same pipe and fitting conditions, the
It showed three times the pull-out prevention power. Further, even when a pulling force is applied to the tube 8, the biting portion by the blade portion 21 is sealed from the inner and outer portions by the elastic ring 3, thereby ensuring sufficient anti-corrosion performance. Since the pipe removal stopper of the present invention bites into the outer peripheral surface of the pipe easily, stably, and strongly, the length of the pipe inserted into the joint body can be shortened.

[Effect of the idea]

As explained above, the pipe joint of the present invention has a much larger force to prevent the pipe from being pulled out compared to conventional ones, and since the push ring starts from the biting part at the beginning of tightening and continues to bite at the same biting part until the end,
There is no slippage at the biting part, no extra scratches are left on the outer circumferential surface of the tube, and the length of tube insertion into the joint body can be shortened.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention,
Fig. 1 is a partial cross-sectional view before connection, Fig. 2 is a side view of the pipe removal stopper shown in Fig. 1, Fig. 3 is an enlarged view of the main part of Fig. 1 after tightening the press ring, Fig. 4 5 shows an enlarged view of the main part after the push ring is tightened, and FIG. 5 shows an enlarged view of the main part showing the state when a pull-out force is applied to the tube of FIG. 4. FIG. 6 is a sectional view showing a conventional pipe removal stopper, and FIG. 7 is a sectional view showing a pipe joint using the conventional pipe removal stopper. 1... Pipe removal stopper, 2... Biting member, 3...
...Elastic ring, 4...Joint body, 5...Press ring, 6
...Putskin, 7...Retainer, 8...Pipe, 21
...blade portion, 22...conical outer surface, 53...tapered inner surface.

Claims (1)

[Scope of utility model registration request] One end of the pipe is inserted into the enlarged diameter part of the joint body, a packing is interposed between the inner surface of the enlarged diameter part and the outer surface of the pipe, and the packing is inserted into the joint body through a ring placed on the end side of the packing. A push ring is provided which has a tapered inner surface that is pushed toward the center and narrows toward the end, and a pipe removal stopper is installed between the tapered inner surface and the outer surface of the pipe to push the push ring toward the joint body side. In a pipe joint that tightens a pipe by tightening, the retaining tool has an annular blade part on the inner side where the tips of the protruding blades face the inner surface of the pipe and are on the same plane, and the outer side has an annular blade part that protrudes toward the inner surface of the pipe. 1. A pipe joint comprising a recess member having a smooth conical surface with respect to the normal to the pipe, and an elastic ring that connects and holds a plurality of recess members disposed around the outer circumference of a pipe in an annular manner.