JPH10160071A - Insertion type pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform sure and strong connection while preventing malfunction of connection of a joint by arranging a coming-off preventive ring provided with two pawl streaks on a circular recession, and making the pawls bite into a surface of a pipe body due to movement of the pipe body in the pulling-out direction and pressurizing by means of a circular tapered surface. SOLUTION: A circular recession 7 having a circular tapered surface 6 which is reduced in a diameter toward a hub 5 is formed on an inner periphery of each of the both end hubs 5 of a joint main body 1. A coming-off preventive ring 8 is arranged on the circular recession 7. Pawls 10 and 11 are formed on the coming-off preventive ring 8 alternatively at specified intervals. A pipe body is inserted until it is abutted against a stopper 2, and then moved in the pulling-out direction. The coming-off preventive ring 8 is moved together to the side of the hub 5 in the circular recession. A tapered outer peripheral surface 9 is pressurized by means of an outer peripheral surface of the pipe body due to the circular tapered surface 6. The pawl portions 10, 11 bite into the outer peripheral surface of the pipe body. The coming-off preventive ring 8 is moved to a portion of the circular tapered surface 6 with a smallest diameter for keeping coming-off prevention with certainty.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the connection of a galvanized steel pipe for an underground wire, a steel pipe for cable protection, and a carbon steel pipe for piping by inserting a headless pipe having an unprocessed pipe end. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint, and more particularly, to a plug-in type pipe joint provided with a retaining ring that bites into an outer periphery of a pipe body when the pipe body moves in a pulling-out direction and prevents the pipe body from being pulled out.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional pipe joint to which an unmachined headless pipe is inserted and connected is an annular taper having a diameter reduced toward a receiving side on an inner periphery of a joint body a. A retaining ring c is provided on the surface b. The retaining ring c has an outer peripheral surface d that moves along the annular tapered surface b, and a single claw e that circles the inner peripheral side. When the end of the pipe f inserted into the joint body a moves in the withdrawing direction, the surface of the annular taper surface b of the joint body a causes the pawl of the retaining ring c to be formed. It is known that the portion e is cut into the outer periphery of the tube f to prevent it from falling off.

[0003]

However, the tube f
Is rarely inserted in such a manner as to be linearly coincident with the center axis when inserted into the joint main body a, and is often inserted in a state where the shaft is slightly deviated from the center axis. Since the retaining ring c described in the prior art is designed to bite into the outer peripheral surface of the pipe f only by a single claw portion e that goes around the inner peripheral side, the pipe f is connected to the center axis of the joint body a. When inserted slightly obliquely with respect to this, the retaining ring c is also pushed in with a slightly obliquely axially displaced posture, and in particular, the annular tapered surface b has an enlarged diameter on the back side in the pushing direction. Therefore, it is easy to be pushed in an oblique state, and it is inserted into the outer periphery of the tubular body f in a state of shaft blur. When the tube f moves in the pulling-out direction and moves in a direction deviating from the center axis, the claw portion e does not bite into the entire outer periphery of the tube f, and a part of the claw e is extremely small. And the retaining ring itself is caught in the middle of the annular taper surface b, and the pipe f of the retaining ring c is caught.
Inadequate penetration into the slab resulted in reduced pull-out force or loss of water tightness.

The joint body a provided with the above-mentioned retaining ring c has not been used much in practice because of the various problems described above, and the dresser which has been widely used in the past has been used. Shaped fittings and bite type fittings are commonly used, or more recently, fittings having a structure in which a retaining ring having a polygonal surface and a wedge-shaped packing are tightened with a union nut have been used. In any case, the pipe joint requires not only a difficult operation to tighten the union nut with a pipe wrench, but also a number of problems such as a decrease in pull-out force and a loss of water tightness depending on the tightening force. there were.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a joint body with a retaining ring having two claw portions at an axial front end and a rear end. The claws uniformly penetrate the outer periphery of the pipe body to reliably prevent the pipe from falling off, and complete sealing is maintained by providing a sealing member such as an O-ring and packing on the inner circumference of the joint body. Another object of the present invention is to provide a plug-in type pipe joint which can be bent with a large bending radius at a connection portion.

[0006]

In order to achieve the above object, a plug-in type pipe joint according to the present invention is provided with a stopper projecting inward at a central portion in the longitudinal direction and a predetermined interval on both sides of the stopper. A joint body having a sealing member attached to the inner periphery at the closed position is provided with an annular concave portion having an annular tapered surface whose diameter is reduced toward the receiving side, and a retaining ring is installed in the annular concave portion. The retaining ring is formed by circumferentially forming two claw portions protruding toward the center at the front end and the rear end in the axial direction, and the retaining ring is moved by moving the pipe inserted into the joint body in the withdrawing direction. The two claws are pressed against the surface of the annular taper and bite into the surface of the tubular body. Further, of the two claw portions, the claw portion on the far end side has an outer surface perpendicular to the center axis and an inner surface inclined at a predetermined angle, and the claw portion on the receiving side is inclined at a predetermined angle. Outer surface and inner surface.

The claw portion on the back end side of the retaining ring is formed so that one side has a vertical surface with respect to the center axis and the other side has an angle of about 45 ° with respect to the vertical surface, and is on the receiving side. The claws are preferably formed on both sides in an isosceles triangular angle at an angle of about 45 °. It is preferable that the outer peripheral surface of the retaining ring has a taper corresponding to the annular taper surface of the joint body.

Preferably, the stopper is a rubber ring. Preferably, the sealing member is an O-ring or a U-packing.

[0009]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a joint body, and FIG. 2 is an enlarged sectional view of a main part of a retaining ring. The joint body 1 of the present invention has a stopper-2 protruding inward at a central portion in the longitudinal direction.
An annular concave portion 3 is provided on the inner periphery of the stopper 2 at a predetermined interval on both sides, and a sealing member 4 is mounted in the annular concave portion 3; An annular concave portion 7 having an annular tapered surface 6 whose diameter is reduced toward the receiving port 5.
The annular recess 7 is formed by providing a retaining ring 8.

The retaining ring 8 is connected to the joint body 1.
Having an outer peripheral surface 9 having a taper corresponding to the annular taper surface 5, and a claw 10 making a round around the inner circumference on the far end side and a claw making a round around the inner circumference on the side of the receptacle 5. 11 are provided at a predetermined interval from each other, and the claw 10 on the back end side is inclined at a predetermined angle to a side opposite to the outer surface 10 a that makes the side wall 12 on the back end side of the retaining ring 8 perpendicular to the center axis. Inner surface 10b
For example, the inner surface 10b is formed in a trapezoidal triangular shape in which the inner surface 10b is inclined at an angle of about 45 ° with respect to the vertical side wall 10a, and the claw 11 on the receiving port 5 side has an outer surface 11a inclined at a predetermined angle. The inner surface 11b and the inner surface 11b are formed in a mountain shape. For example, the inner and outer surfaces 11a and 11b are formed in an isosceles triangular cross section at an angle of about 45 °, and the claw portion 10 on the far end and the claw portion on the side of the receptacle 5 are formed. Eleven toes have the same inner diameter and are formed slightly smaller than the outer shape of the tube 13 inserted into the joint body 1.

The groove width of the annular concave portion 7 for mounting the retaining ring 8 of the joint main body 1 is formed to be large by the amount of the push-out movement of the retaining ring 8, and the annular tapered surface 6 is arranged with respect to the center axis. Is preferably formed at about 15 °. Similarly, the outer peripheral surface 9 of the retaining ring 8 is preferably formed at about 15 ° with respect to the central axis so as to correspond to the annular tapered surface 6.

A stopper-2 is provided at the center of the joint body 1.
The annular recess 14 is provided, and a stopper 2 is fitted into the annular recess 14 so as to protrude inward. Preferably, the stopper-2 is made of a soft material such as rubber or synthetic resin.

Further, the sealing member 4 is provided with an O-ring 15 or a U packing 1 as shown in FIGS.
It is preferable to mount 6,17. That is, the U-packing 15 shown in FIG. 6A has a V-shaped notch 1 on both sides in the axial direction.
6a is provided with a tongue piece 16b which expands in the four corner directions. The U packing 17 of FIG. 6 (b) has a V-shaped notch 17a provided only on one side in the axial direction. It has a tongue piece 17b that expands in the inner and outer peripheral directions on one side surface.

In the joint body 1, the insertion dimension of the tube 13 is set by the diameter of the socket 5, the inner circumference of the joint body 1 is formed to have a slightly larger diameter than the diameter of the socket 5, and is connected to the joint body 1. The bent tube 13 has a deflection angle of about 2 ° on one side. The sealing member 4 provided on the inner periphery of the joint main body 1 maintains the sealing property corresponding to the bending angle, and as shown in FIG. 6, it is possible to pipe with a large bending radius. When the retaining ring 8 is located at the maximum diameter on the deep end side of the annular tapered surface 6 of the annular concave portion 7, the tips of the two claw portions 10 and 11 are substantially equal to the diameter of the receiving port 5. Preferably, they are formed to have the same diameter. It is to be noted that the axial width of the retaining ring 8 is set to about 8 mm, and the axial groove width of the annular recess 7 is set to about 12 mm so that the moving distance of the retaining ring 8 is set to about 4 mm. preferable.

The joint body 1 having the above-described structure is configured such that when a pipe body 13 called a headless pipe whose pipe end is not machined is inserted,
The retaining ring 8 is pushed by the distal end of the tubular body 13 and moves toward the diameter-expanding side at the far end of the joint body 1. At this time,
The inner surface 10b of the claw 10 on the back end of the retaining ring 8 and the outer surface 11a of the claw 11 on the opening side are inclined at a predetermined angle toward the back end, for example, about 45 °. 11 are simultaneously pushed and expanded so that the retaining ring 8 moves to the back side without biting into the outer peripheral surface of the tube 13 and the tube 1
3 can be further inserted until it hits the central stopper-2, and the two claws 10 and 11 provided at predetermined intervals in the axial direction prevent the shaft 3 from slipping off. The ring 8 is inserted into the outer peripheral surface of the tube 13.

When the pipe 13 is fully inserted until it hits the stopper 2 of the joint body 1 and the pipe 13 is moved in the pulling-out direction, the stopper ring 8 inserted around the outer circumference of the pipe 13 also becomes The annular recess 7 is integrally moved to the receiving port 5 side, and the taper outer peripheral surface 9 of the retaining ring 8 is
Is pressed against the outer peripheral surface of the tubular body 13 by the annular tapered surface 6, and the pressing causes the two claw portions 10, 1 of the retaining ring 8 to be pressed.
1 bites into the outer peripheral surface of the tube 13, and the retaining ring 8 moves to the position where the diameter of the annular tapered surface 6 is reduced to the minimum, and the tube 1
3 is securely retained.

Further, since the retaining ring 8 is provided with two claw portions 10 and 11 at predetermined intervals on the far end side and the receiving side, the pipe 13 coincides with the central axis of the joint body 1. When the pipe 13 is inserted in a slightly oblique direction with respect to the center axis of the joint main body 1 as well as when the pipe 13 is inserted in a state where it is inserted, the two claw portions 10 and 11 provided at a predetermined interval are removed. The provided retaining ring 8 can be uniformly engaged with the outer peripheral surface of the tube 13, and therefore, when the tube 13 is pulled out, the retaining ring 8 is inclined with respect to the central axis of the tube 13. The claw portions 10 and 11 are made to bite into the outer periphery of the tubular body 13 uniformly without causing the occurrence of the cracks. As a result, the drawing force of the galvanized steel pipe at a nominal diameter of 125 A is 10,000 kg, which is excellent performance. The joint body 1 is connected to the pipe 1
3 is set, and the inner circumference of the joint body 1 is formed to have a slightly larger diameter than the socket 5, so that the pipe 13 connected to the joint body 1 has a deflection angle of about 2 ° on one side. The sealing member 4 provided on the inner periphery of the joint body 1 can maintain the sealing performance corresponding to the bending angle, and can be piped with a large bending radius as shown in FIG. Becomes

[0018]

Since the present invention has the above-described structure, the two claw portions provided at a predetermined interval allow the tubular body to be inserted or pulled out in a slightly inclined direction with respect to the center axis. Even if it does, it can be uniformly engaged with the outer peripheral surface of the tubular body without being affected by the inclination of the tubular body, and uniform and good biting can be obtained without causing strong local biting. As a result, it is possible to securely and firmly connect without causing a connection failure at the joint portion, and to obtain good watertightness. That is, in a conventional dresser-type pipe joint and a bite type pipe joint, a pull-out force of a pipe having a nominal diameter of 125 A at a tightening torque of 1,000 kgf / cm is 6,000 kg and a tightening torque of 3
Even when the water pressure was 15 kgf / cm ² even at 000 kgf / cm, the pipe joint of the present invention obtained a test result having excellent performance of 10,000 kg of drawing force and 40 kg of water pressure under the same conditions. In addition, the pipe joint of the present invention is connected only by inserting a pipe body, and therefore, the pipe connecting operation becomes extremely easy and simple, and the laying time is shortened. In addition, even when a bending angle is generated in the connection portion, the two claws surely prevent the pipe from coming off, and at the same time, maintain perfect watertightness by a sealing member provided on the inner periphery of the joint main body. This has the effect of sufficiently coping with the settlement.

[Brief description of the drawings]

FIG. 1 is a sectional view of a joint body according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of a retaining ring attached to the joint body of the present invention.

FIG. 3 is a cross-sectional view when a pipe is inserted into the joint main body of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a claw of a retaining ring bites into a pipe inserted into a joint body of the present invention by a pulling force.

FIGS. 5 (a) and (b) are cross-sectional views of main parts of respective U packings mounted on the joint body of the present invention.

FIG. 6 is a plan view showing, in a partial cross section, a state where piping is performed at a bending radius based on a bending angle.

FIG. 7 is a sectional view of a main part of a conventional retaining ring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint main body 2 Stopper 3 Annular recess 4 Sealing member 5 Receptacle 6 Annular taper surface 7 Annular recess 8 Retaining ring 9 Outer peripheral surface 10 Claw 10a Outer surface 10b Inner surface 11 Claw 11a Outer surface 11b Inner surface 12 Outer wall 13 Tube 14 Cyclic Recess

Claims (2)

[Claims] 1. A joint body having a stopper protruding inward at a central portion in the longitudinal direction, and a sealing member mounted on an inner periphery at predetermined intervals on both sides of the stopper is provided on a receiving side. An annular concave portion having an annular tapered surface that is reduced in diameter to the periphery is provided,
A retaining ring is provided in the annular concave portion, and the retaining ring is formed by circumferentially forming two claw portions projecting toward the center at the front and rear ends in the axial direction, and is a tube inserted into the joint body. A plug-in type pipe joint characterized in that the two claw portions of the retaining ring are pressed against the surface of the annular taper and bite into the surface of the tubular body by the movement of the retaining ring in the drawing direction. 2. A joint body comprising a stopper protruding inward at a central portion in the longitudinal direction, and a sealing member mounted on an inner periphery at a predetermined interval on both sides of the stopper is provided on a receiving side. An annular concave portion having an annular tapered surface that is reduced in diameter to the periphery is provided,
The ring-shaped recess is provided with a retaining ring that is pressed against the annular taper surface by the movement of the tube inserted into the joint body in the pulling direction and bites into the surface of the tube, and the retaining ring has an axial front end. The rear end is formed by circumferentially protruding two claw portions projecting toward the center side, and the claw portion on the back end side is formed by an outer surface perpendicular to the center axis and an inner surface inclined at a predetermined angle with respect to the center axis. A plug-in type pipe joint characterized in that the claw portion on the mouth side has an outer surface and an inner surface inclined at a predetermined angle.