JP2000146047A - Insertion type pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To let pipe insertion resistance be made small when an insertion type joint is used for piping works for connecting each internal lined steel pipe to be used for a water pipe line, and prevent a pipe and one pipe joint from being relatively rotated. SOLUTION: This insertion type pipe joint is formed out of a pipe joint body 1 having a pipe insertion hole, and of a bite-in cylinder 2 at its end surface. In this case, the bite-in cylinder 2 is provided with a slit 23 provided for a part of the cylinder, a screw 24 adjusting the opening of the slit, and with a projected part 22 for biting in the inside of a through hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug-in type pipe joint which can be used for a water supply pipe or the like, and more particularly, to a plug-in type pipe joint which has a small pipe insertion resistance and can make the pipe self-supporting. It relates to a pipe joint.

[0002]

2. Description of the Related Art An example of a plug-in type pipe joint is disclosed in
There is the one described in JP-A-203688. This pipe joint has a configuration shown in a sectional view in FIG. In the figure, P is an inner lining steel pipe having a lining layer P1. Reference numeral 3 denotes a metal cylindrical pipe joint main body of the pipe joint, the inner peripheral surface of which has a first annular space portion 31 having a tapered surface 311 whose diameter gradually increases inward, and is parallel to the axis. A second annular space portion 33 having a large inner surface and both side surfaces perpendicular to the axis is formed in this order from the outside.

A retaining ring 32 is formed in the first annular space 31 so as to be radially expandable and contractible in the form of a C ring having a part cut off on the circumference so as to be movable in the axial direction. The tapered surface 3 is located at a position deeper than the stop ring 32.
A ring-shaped support rubber for restricting the movement of the retaining ring 32 toward the large-diameter side of 11 and preventing the retaining ring 32 from rattling is fitted. In the second annular space portion 33, a water-stop packing 34 that elastically contacts the outer peripheral surface of the inner lining steel pipe P is fitted.

A pipe end anticorrosion core 35 is attached to the inner peripheral surface of the pipe joint body 3. This pipe end anticorrosion core 35
Is a cylindrical portion 35 that comes into contact with the inner surface of the inner lining steel pipe P.
Numeral 1 is an integral molding of a synthetic resin material. An annular groove is formed at the outer peripheral end of the cylindrical portion 351, and an O-ring 352 is fitted into the groove to improve watertightness between the pipe end anticorrosion core 35 and the lining layer P <b> 1 of the inner lining steel pipe P. Is increasing.

[0005] When connecting the inner lining steel pipe P to this plug-in type pipe joint, an annular groove is provided on the outer peripheral surface of the steel pipe at a predetermined distance from the tip of the steel pipe, and the inner and outer surfaces of the steel pipe are chamfered. The steel pipe P is inserted into the opening from the end face of the pipe joint, and the tip of the steel pipe is inserted into the pipe end corrosion protection core 35 of the pipe joint.
Abut the wall behind. When the steel pipe is inserted into the pipe joint, the tubular part 351 of the pipe end anticorrosion core 35 comes into contact with the lining layer P1 on the inner surface of the steel pipe, and the O-ring 352 fitted to the tip of the tubular part 351 makes the space therebetween watertight, The water-stop packing 34 fitted in the second annular space 33 of the pipe joint body 3 elastically contacts the outer peripheral surface of the steel pipe P to make it watertight. In addition, the retaining ring 32 fitted in the first annular space portion 31 fits into an annular groove provided on the outer peripheral surface of the steel pipe. When a force is applied to the steel pipe P such that it comes off from the pipe joint body 3, the retaining ring 32 attempts to move outward together with the steel pipe P, but a force is applied by the tapered surface 311 so that the retaining ring 32 is reduced in diameter. So
As the steel pipe P bites into the outer peripheral surface more strongly,
Can be prevented from falling out of the pipe joint body 3. When a force acts on the steel pipe P further into the pipe joint body 3, the tip of the steel pipe P abuts against the wall at the back of the pipe end corrosion protection core 35 and supports the retaining ring 32. Because it tries to hold down the supporting rubber, it can be prevented from entering the back. In this way, the steel pipe can be prevented from falling off and watertight only by being inserted into the pipe joint.

[0006]

Although such a plug-in type pipe joint is convenient from the viewpoint of piping work,
As can be seen from the fitting shown in FIG. 8, a relative rotation between the fitting and the connecting pipe may occur. Generally, widely used fittings are screw-in type, and in the case of screw-in type fittings, since the fitting and the connecting pipe are screw-connected, relative rotation does not occur in a normal use state of the pipe. . For this reason, the piping using the plug-in type pipe joint is handled in the same manner as the pipe using the screw-in type pipe joint, so that the relative rotation often causes inconvenience.

Further, when the inner lining steel pipe P is inserted into the insertion type pipe joint shown in FIG. 8, its insertion resistance is large. The tip of the steel pipe is first a retaining ring 32
, The retaining ring 32 is expanded. Further, as the steel pipe is inserted, the expanded retaining ring rubs the outer periphery of the steel pipe. Next, the tip of the steel pipe hits the water stop packing 34, and the packing is expanded. Thereafter, resistance is exerted on the inner peripheral surface of the water-stop packing sliding on the outer periphery of the steel pipe. Thereafter, the lining layer P1 on the inner surface of the steel pipe is rubbed against the O-ring 352 at the tip of the pipe end anticorrosion core 35. As described above, the resistance of the retaining ring 32, the waterproof packing 34, and the O-ring 352 are added as the pipe insertion resistance, and the resistance of the retaining ring 32 is the largest among these. For this reason, when a steel pipe having a nominal diameter of 20 A is used, the insertion resistance is 9 to 10 kg.

Therefore, according to the present invention, a plug-in type pipe joint which eliminates the resistance due to the retaining ring at the time of pipe insertion to reduce the pipe insertion resistance and does not cause relative rotation between the pipe and the pipe joint after the pipe is inserted. The purpose is to provide.

[0009]

The plug-in type pipe joint according to the present invention has a pipe joint body having a pipe insertion hole from the end face toward the inside, and a bite cylinder provided on the end face of the pipe joint body. , The biting cylinder is a through hole through which the pipe can pass, and a slit provided in a part of the cylinder in the axial direction,
The biting projection provided on the inner peripheral surface of the through hole, the end surface of the biting cylinder, a part of the end surface of the cylinder is coaxial with the end surface of the pipe joint body, and the through hole and the pipe insertion hole of the pipe joint body are coaxial. In addition to having a fixing portion that is fixed, the pipe joint body has a packing groove on the inner surface of the tube insertion hole near the end face, and the packing is held in the packing groove. I do.

[0010] In the plug-in type pipe joint, the pipe joint body and the biting cylinder are integrally formed, and the end face of the pipe joint body and the biting cylinder can be separated by a cut perpendicular to the pipe insertion hole. . Further, the pipe joint body has a screw in the axial direction from its end face toward the packing groove, and the biting cylinder has a screw that engages with the screw from its end face. Can be engaged with these screws and fixed by hitting a pin from the biting cylinder to the end face of the pipe joint body.

[0011] In the present invention, the packing held in the packing groove has an extension part which partially extends into the slit of the biting cylinder, and the extension part has a hole communicating with the packing groove. It is preferable to have.
In the present invention, it is preferable that an indicator piece made of a material more brittle than the cylinder is sandwiched in the slit of the biting cylinder.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The plug-in type pipe joint of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view showing a plug-in type pipe joint according to an embodiment of the present invention in a partial cross section.
FIG. 3 is a cross-sectional view of the biting cylinder, FIG. 3 is a side view partially showing a plug-in type pipe joint of another embodiment of the present invention, FIG. 4 is a cross-sectional view of the biting cylinder, and FIG. FIG. 6 is a side view showing the plug-in type pipe joint of the embodiment of the present invention in a partial cross section.
Is a cross-sectional view of the biting cylinder, and FIG. 7 is a perspective view of a packing used for the plug-in type pipe joint shown in FIGS.

The plug-in type pipe joint shown in FIGS. 1 and 2 shows a socket pipe joint as an example, and is composed of a cylindrical pipe joint body 1 and a biting cylinder 2 provided on both end surfaces 11 thereof. ing. The pipe joint body 1 has a pipe insertion hole 12 from the end face 11 toward the inside, and a stopper 1 with which the inserted pipe comes into contact with the inside of the pipe insertion hole 12.
3 are provided so as to protrude inward in the radial direction. Further, a packing groove 14 is provided on the inner surface of the tube insertion hole 12 near the end face 11, and an annular packing 15 is held in the packing groove 14. Here, the packing 15 has a lip 151 on the inner peripheral surface facing inward in the depth direction of the tube insertion hole. The biting cylinder 2 has a through hole 21 that can receive and pass the tube, and has several peaks of biting projections 22 on the inner peripheral surface of the through hole 21. A slit 23 is provided in a part of the circumference of the biting cylinder 2 in the radial direction, and the slit 23 extends in the axial direction, and the biting cylinder 2 has a C shape. An opening adjusting screw 24 is provided across the slit 23 near the slit 23 of the C-shaped biting cylinder 2. The biting cylinder 2 has a fixing portion 25 so that the through hole 21 and the pipe insertion hole 12 of the pipe joint main body 1 are coaxial and fixed to the end face 11 of the pipe joint main body 1.

The inner lining steel pipe is passed through the through-hole 21 of the biting cylinder 2 of this plug-in type pipe joint, and the pipe joint body 1
When inserting into the tube insertion hole 12, the screw 24 for adjusting the opening degree of the biting cylinder 2 is loosened, and the C-shaped biting cylinder 2 is opened. Then, since the biting projection 22 attached to the inner peripheral surface of the through hole 21 is open, the steel pipe easily passes through the through hole 21 and pushes and expands the packing 15 so that the stopper 13 located at the back of the pipe insertion hole 12 can be opened. Inserted until
At this time, the resistance received by the inserted tube is only due to the packing 15, and is 4 to 5 kg in the case of a nominal diameter of 20 A.
As a result, the tube insertion resistance was about half of the conventional tube insertion resistance of 9 to 10 kg. After inserting the steel pipe into the plug-in type pipe joint, the opening adjusting screw 24 attached to the biting cylinder 2 is tightened so that the biting projection 22 is bitten into the outer peripheral surface of the steel pipe. Since the tip of the biting protrusion 22 is made to bite into the steel pipe in this way, it is preferable that the tip is harder than the outer peripheral surface of the steel pipe.

In the plug-in type pipe joint of the present invention, the bite cylinder 2 is fixed to the pipe joint main body 1 and the steel pipe has the bite projection 22 of the bite cylinder 2 inserted therein. Does not rotate with respect to the fitting. It will also be apparent that, since the biting projections bite into the steel pipe, it is no longer necessary to provide a groove for inserting a lock ring into the steel pipe which was required in the conventional plug-in type pipe joint.

In the pipe fitting for insertion shown in FIGS. 1 and 2, the pipe fitting body 1 and the biting cylinder 2 are made of a single piece, for example, a casting such as a malleable or ductile. Fixed part 25 of biting cylinder 2
In a manner perpendicular to the tube insertion hole 12 so as to leave
6 is attached. When the opening adjusting screw 24 attached to the slit 23 is opened and closed, the C-shaped biting cylinder 2 opens and closes with respect to the fixing portion 25.

In this embodiment, a packing and an opening adjustment screw are attached to a machined screw hole, cutout, packing groove, and biting projection using an integrated casting material. For this reason, since the manufacturing process is the same as that of forming a conventional cast pipe joint, a large change in the manufacturing process is not required. Since the pipe joint is integrated, handling during piping is not only easy, but also parts are not lost when handling the pipe joint before piping.

In the plug-in type pipe joint of another embodiment shown in FIGS. 3 and 4, the pipe joint body 1 has a female screw 16 in the axial direction from its end face 11 toward the packing groove 14 inside the pipe insertion hole.
The biting cylinder 2 has a male screw 27 which engages with the female screw 16 from its end face, and is assembled to the pipe joint body 1 by these screws. A pin 28 is struck on the side of the biting cylinder 2 opposite to the slit 23, and the pin presses and fixes the end face 11 of the pipe joint body 1 to form a fixing portion 25. Since the C-shaped biting cylinder 2 opens and closes at the slit 23 with the pin 28 as the center, the screw 24 for opening adjustment is opened when the steel pipe is inserted, and the screw for opening adjustment is inserted after the steel pipe is inserted. By tightening 24, the biting protrusion 22 can be cut into the outer peripheral surface of the steel pipe. In this way, by making the biting cylinder 2 different from the pipe joint body 1, the biting cylinder 2 can be made of a material harder than the main body 1.

In still another embodiment shown in FIGS. 5 and 6, the packing 17 held in the packing groove 14 of the pipe joint body 1 has a structure shown in a perspective view in FIG. 17 has an extension 172 extending into the slit 23 provided in the biting cylinder 2.
It has a hole 173 communicating with the packing groove 14 therein. This packing 17 is also used for the pipe joint body 1.
When it is inserted into the packing groove 14 in the back of the tube insertion hole,
It also has a lip 171 facing the inside diameter so that it can be sealed with the outer periphery of the steel pipe. When the pipe is inserted into the pipe insertion hole 12, the inner part of the packing groove 14 communicates with the inside of the inserted pipe, and the packing 17.
The fluid in the pipe leaks from the hole 173 attached to the pipe. The extension 17 is inserted into the slit 23 of the biting cylinder 2.
2, if the opening adjustment screw 24 is sufficiently tightened, the extension 172 is crushed and the hole 173 is closed. In this embodiment, when the opening adjusting screw 24 is not sufficiently tightened, the fluid inside the pipe leaks through the hole 173, so that it can be confirmed whether the screw 24 has been sufficiently tightened.

5 and 6, an indicator piece 29 made of a material that is more brittle than the material of the biting cylinder 2 is inserted into the slit 23 of the biting cylinder 2. When the opening adjusting screw 24 is sufficiently tightened, the indicator piece 29 is crushed and removed. This makes it possible to know whether or not the opening adjustment screw 24 has been sufficiently tightened.

[0021]

As described above, in the plug-in type pipe joint according to the present invention, there is no resistance due to the retaining ring at the time of pipe insertion, and the pipe insertion resistance can be reduced.
After piping, there was no relative rotation between the pipe and the fitting.

Further, since there is no separate part separate from the plug-in type pipe joint, handling at the time of piping is easy. In addition, since the pipe is tightened with the screw for adjusting the opening of the biting cylinder, if it becomes necessary to disassemble the pipe, loosen the screw for adjusting the opening to disassemble the part without applying excessive force to the bite part Can be.

[Brief description of the drawings]

FIG. 1 is a side view showing a partial cross section of a plug-in type pipe joint according to an embodiment of the present invention.

FIG. 2 is a sectional view of a biting cylinder of the plug-in type pipe joint shown in FIG.

FIG. 3 is a side view showing a plug-in type pipe joint according to another embodiment of the present invention in a partial cross section.

FIG. 4 is a sectional view of a biting cylinder of the plug-in type pipe joint shown in FIG. 3;

FIG. 5 is a side view showing, in a partial cross section, still another plug-in type pipe joint of the present invention.

6 is a sectional view of a bite cylinder of the plug-in type pipe joint shown in FIG. 5;

FIG. 7 is a perspective view of a packing used in still another plug-in type pipe joint of the present invention.

FIG. 8 is a sectional view of a conventional plug-in type pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fitting main body 11 End face 12 Pipe insertion hole 13 Stopper 14 Packing groove 15, 17 Packing 151, 171 Lip 172 Extension part 173 hole 16 Female screw 2 Biting cylinder 21 Through hole 22 Biting projection 23 Slit 24 Opening adjustment screw Reference Signs List 25 fixing portion 26 cut 27 male screw 28 pin 29 indicator piece 3 pipe joint body 31 first annular space portion 311 tapered surface 32 retaining ring 33 second annular space portion 34 waterproof packing 35 pipe end anticorrosion core 351 tubular portion 352 O Ring P Inner lining steel pipe P1 Lining layer

Continuing on the front page (72) Inventor, Nakata, 2nd Daifuku, Kuwana-shi, Mie Prefecture Inside the Kuwana Plant, Hitachi Metals Co., Ltd. Inventor Tetsuhiro Okuyama 75 Nojiri, Ritto-cho, Kurita-gun, Shiga Prefecture Sekisui Chemical Co., Ltd. F-term (reference) 3H015 DA01 DA10

Claims (5)

[Claims] 1. A plug-in type pipe joint having a pipe joint body having a pipe insertion hole from the end face toward the inside and a bite cylinder provided in an end face of the pipe joint body, wherein the bite cylinder is a pipe through which the pipe passes. A possible through-hole, a slit provided in a part of the cylinder in the axial direction, a biting projection provided on the inner peripheral surface of the through-hole, and a part of the end face of the cylinder at the end face of the biting cylinder The end of the pipe joint body has a fixing portion for fixing the through hole and the pipe insertion hole of the pipe joint body coaxially, and the pipe joint body has a packing groove in the inner surface of the pipe insertion hole near the end face. Wherein the packing is held in the packing groove. 2. The pipe joint body and the biting cylinder are integrally formed, and the end face of the pipe joint body and the biting cylinder are separated by a cut perpendicular to the pipe insertion hole. 2. The plug-in type pipe joint according to 1. 3. The pipe coupling body has a thread in an axial direction from an end face thereof toward a packing groove, and the biting cylinder has a screw engaging with the screw from the end face thereof. 2. The plug-in type pipe joint according to claim 1, wherein the screw is engaged with the joint body by these screws, and the pin is fixed to the fixing part from the biting cylinder to the end face of the pipe joint body. 4. The packing held in the packing groove has a part extending into the slit of the biting cylinder, and a part of the packing having a hole communicating with the packing groove. The plug-in type pipe joint according to any one of claims 1 to 3, wherein: 5. The plug-in type pipe joint according to claim 1, wherein an indicator piece made of a material more brittle than the cylinder is sandwiched in the slit of the biting cylinder.