JP3136312B2 - Plug-in fittings - Google Patents

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 has an outer peripheral surface 9 having a taper corresponding to the annular tapered surface 5 of the joint main body 1, and the claw portion 1 making a round around an inner periphery on the back end side.
0 and a claw portion 11 surrounding the inner periphery on the side of the receiving port 5 are provided at a predetermined interval from each other, and the claw portion 10 on the back end side is centered on a side wall 12 on the back end side of the retaining ring 10. The outer surface 10a is formed to be vertical and the inner surface 10b inclined at a predetermined angle on the opposite side.
0a is formed in a trapezoidal cross section inclined at an angle of about 45 ° with respect to the inner surface 10b with respect to the insertion direction of the tube.
Is inclined at a predetermined angle in the direction of insertion of the tube,
The outer surface 10a perpendicular to the central axis in the drawing direction is
The claw of the claw portion 10 is provided in a direction in which the tube is pulled out.
A vertical outer surface 10a with the tip directed in the tube withdrawal direction
The claw portion 11 on the side of the receiving port 5 is formed in a mountain shape in cross section by an outer surface 11a and an inner surface 11b which are inclined at a predetermined angle. For example, the inner and outer surfaces 11a and 11b are approximately 45 °. Is formed in the shape of a cross section of an isosceles triangle with an angle of
The inner surface 10a which is inclined with respect to the insertion of the tube is formed so as to reduce the friction of the tube surface and to cope with the pressing force from the tube surface in the direction of the central axis firmly. The outer diameter of the tube 13 inserted into the joint body 1 is made slightly smaller so that the toe of the claw portion 11 on the side of the portion 10 and the socket 5 has the same inner diameter.

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 main body 1 having the above-described configuration is configured such that when a pipe body 13 called a headless pipe whose pipe end becomes unprocessed 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 side of the retaining ring 8 and the outer surface 11a of the claw 11 on the opening side, that is, the insertion direction of the tubular body 13
And a predetermined angle toward the back end side, for example, about 4
Since the inclination of 5 ° is provided, the tip of the tube 13 is inclined
, The pawls 10 and 11 are simultaneously pushed out and spread, and the retaining ring 8 moves to the back side without biting into the outer peripheral surface of the tubular body 13, and the tubular body 13 is further inserted to stop the stopper 13 at the center. can be inserted until it hits the 2, its
Then, the two claws 10 and 11 that are pushed out are connected to the tube 13.
The retaining ring 8 is inserted into the outer surface of the tube 13 without causing axial misalignment by the two claw portions 10 and 11 provided at predetermined intervals in the axial direction. Is done.

After the tube 13 is fully inserted until it hits the stopper 2 of the joint body 1 and the tube 13 is moved in the pulling-out direction , the two claws 1 are attached to the surface of the tube 13.
A retaining ring 8 for locking 0, 11 receives the annular recess 7.
It moves integrally to the mouth 7 side. In particular, retaining ring 8
The claw portion 10 on the back end side of the claw has an outer surface 10a perpendicular to the center axis.
With the tip facing the pulling direction,
To move the retaining ring 8 to the pull-out side.
Accordingly, the retaining ring 8 can reliably move the annular concave portion 7 toward the receiving port 7, and the tapered outer peripheral surface 9 of the retaining ring 8 forms the annular tapered surface 6 of the annular concave portion 7.
As a result, the outer peripheral surface of the tubular body 13 is pressed, and the claw 11 on the receiving port 5 side also bites into the outer surface of the tubular body 13 following this pressing, and the two claw portions 10, 11 of the retaining ring 8 are moved. Tube 1
3, the claw 11 on the side of the receiving port 5, which has a mountain shape inclined on both sides, firmly cuts in, and the retaining ring 8 moves to the point where the diameter of the annular tapered surface 6 is reduced to the minimum. stop to keep exits the body 13 reliably and robust.

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 Ring Recess

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-256086 (JP, A) JP-A 63-170678 (JP, U) JP-A-3-81486 (JP, U) JP-A 3- 69385 (JP, U) Jiko 50-43770 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 21/00-21/08

Claims (1)

(57) [Claims] 1. A joint body having a stopper protruding inward at a longitudinal central portion, and a sealing member mounted on an inner periphery at a predetermined interval on both sides of the stopper, is contracted toward a receiving side. An annular recess with an annular tapered surface that dims around is provided,
A retaining ring is provided in the annular concave portion. The retaining ring has a peripheral surface having a taper corresponding to the annular tapered surface and two claw portions projecting toward the center at the front and rear ends in the axial direction. And the claw part on the back end side inserts the tube
Pulling out the inner surface and tube inclined at a predetermined angle to the direction
With respect to the direction, the outer surface is perpendicular to the center axis, and the claw portion on the receiving side has an outer surface and an inner surface inclined at a predetermined angle, and with the movement of the retaining ring to the pulling side, A plug-in type pipe joint, wherein the two claw portions are pressed against an annular tapered surface and bite into the surface of the tube.