JP2000346258A - Release preventive pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superior pull-out preventive effect without enlarging an eating-in groove even in a synthetic resin fluid pipe by constituting the pull-out prevention tool to be movable with its initial eating-in state in a case of a small drawing force, and to allow the pull-out prevention tool to deeply eat-in the fluid pipe via a tapered face, when a large drawing force is applied thereon. SOLUTION: A pipe joint body 2 is formed of chrome steel into an approximately cylindrical shape and diameter-enlarged release prevention parts 2a preventing pulling-out of fluid pipes 3, 4 are formed in the left/right both sides with the center part in the pipe axial direction as the boundary. The release prevention part 2a defines an annular recess 8 set to a tapered presser face 7 gradually contracting its diameter toward the pulling-out direction of the fluid pipe 3 in its internal circumferential face and a claw ring 10 formed into an approximately C shape is stored therein. A plurality of presser bolts 5 are threadedly engaged in the outer circumferential face of the release prevention part 2a and each presser bolt 5 is uniformly contracted with the left end face of the claw ring 10 abutting on the annular stopper 9 so that the claw ring 10 is pressurized to provide the initial bite state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disconnection-preventing pipe joint for connecting fluid pipes such as water pipes while preventing them from coming off.

[0002]

2. Description of the Related Art An example of this type of separation preventing pipe joint is disclosed in Japanese Utility Model Publication No. Hei 4-1434.

[0005] As shown in FIG. 5, an end of the other fluid pipe d having a press ring c externally fitted therein is inserted into a receiving port b of one fluid pipe a via a sealing material e, as shown in FIG. By pressing the inclined surface g of the outer peripheral surface of the retaining member f housed in the concave portion of the inner surface of the pressing ring c with the pushing bolt j via the pressing member i having the pressing surface h having the same inclination, the retaining member f The protrusion (blade portion) k at the tip of the hole is cut into the outer peripheral surface of the fluid pipe d to prevent the fluid pipes from separating.

[0004]

In the above-described conventional joint for preventing separation, the protrusion k of the stopper f is slightly bite into the outer peripheral surface of the fluid pipe d to prevent the initial detachment. When a pull-out force is applied to a and d, the stopper k is slid with respect to the pressing member i, so that the protrusion k
The amount of biting of the steel is increased, and a large retaining force is obtained.

However, as described above, in the structure in which the inclined surface g of the retaining member f is always pressed against the pressing surface h of the pressing member i, there is no play in the pull-out direction of the retaining member f, and the fluid pipe has no fluid. When any pulling force acts on d, the protrusion k immediately bites into the outer peripheral surface of the fluid pipe d.

As a result, in a fluid pipe having a relatively soft surface, such as a synthetic resin pipe made of polyethylene or the like or an outer peripheral surface of an iron pipe covered with a synthetic resin or the like, when a large drawing force acts on the fluid pipe, the fluid pipe becomes The movement of d and the biting of the projection k are performed simultaneously, and there is a possibility that the outer peripheral surface of the fluid pipe is turned up by the projection k or a large biting groove is formed in the pipe axis direction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and when the pulling force is small, the stopper can move in the initial bite state, and when a large pulling force is applied, the fluid stops. An object of the present invention is to provide a detachment prevention pipe joint that can be surely prevented from slipping out even in a fluid pipe made of a synthetic resin or the like by making the pipe bite deeply into the pipe without increasing a bite groove.

[0008]

In order to achieve the above-mentioned object, according to the present invention, there is provided a detachment prevention pipe joint having an inner peripheral portion provided at an end of a substantially cylindrical pipe joint body into which a connection end of a fluid pipe can be inserted. An annular recess is formed as a tapered pressing surface whose surface gradually decreases in diameter in the direction in which the fluid pipe is drawn out, and the outer peripheral surface of the pipe joint body in a portion where the annular recess is formed faces the pipe axis direction. A plurality of push bolts are screwed in such that their tips project into the annular concave portion, and the inner peripheral surface has a blade portion capable of cutting into the outer peripheral surface of the fluid pipe in the annular concave portion. The outer peripheral surface facing the bolt is flat,
When the outer side end outer peripheral surface forms a tapered inclined surface that is inclined in the same direction as the pressing surface and is capable of being elastically deformed in the radial direction in the initial bite state when pressed by the push bolt, It is characterized in that it is housed movably in the tube axis direction such that a required gap is formed between the pressing surface and the inclined surface. According to the present invention having the above-described structure, when the pulling force acting on the fluid pipe is relatively small, the claw ring moves together with the fluid pipe in the initial bite state, and the inclined surface comes into contact with the pressing surface, so that the fluid pipe is detached. Prevention takes place. When a large pulling force is applied, the inclined surface is strongly pressed against the pressing surface, and the bite amount of the blade portion of the claw ring is increased.

In the above-described disengagement prevention pipe joint, the width of the claw ring in the pipe axis direction is increased, and blade portions are formed at both end portions of the inner peripheral surface thereof. It is preferable that the blade portion on the one side be cut into the fluid pipe and that a gap be formed between the inclined surface of the outer peripheral surface and the pressing surface of the annular concave portion. With this configuration, when a large pulling force acts on the fluid pipe, the outer blade portion also bites into the outer peripheral surface of the fluid pipe, so that the restraining force of the fluid pipe becomes large, and a large detachment prevention effect can be obtained.

[0010] In the above-mentioned disengagement prevention pipe joint, in the case where the fluid pipe or the outer peripheral surface thereof is formed of a synthetic resin, it is preferable that the claw ring is formed of a synthetic resin harder than the fluid pipe. In this case, when a pull-out force is applied, the claw ring is slightly elastically deformed and its diameter is easily reduced, so that a large biting groove is formed on the outer peripheral surface of a fluid pipe made of a synthetic resin.

[0011] In the above-mentioned disengagement prevention pipe joint, it is preferable that a contact plate made of a hard metal is fitted to the outer peripheral surface of the claw ring where the push bolt contacts. This prevents the outer peripheral surface of the claw ring with which the push bolt comes into contact from being worn.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a pipe joint 1 for preventing disengagement according to the present invention. A pipe joint body 2 is formed in a substantially cylindrical shape from chrome steel or the like, and is formed on both left and right sides at a center in the pipe axis direction. Is formed with a detachment preventing portion 2a having an increased diameter for preventing the right fluid pipe 3 and the left fluid pipe 4 from coming off. The left and right fluid pipes 3, 4 are made of polyethylene resin. Since the left and right separation preventing portions 2a are symmetrical to each other and have the same configuration, the following description will be made only on the right side, and the description on the left side will be omitted.

A plurality of (for example, six) bosses 6 for screwing the push bolts 5 are provided on the outer peripheral surface of the detachment preventing portion 2a at regular intervals in the centripetal direction. An annular concave portion 8 having a tapered pressing surface 7 whose right end portion is gradually reduced in diameter in a direction in which the fluid pipe 3 comes out is formed on an inner peripheral surface of the separation preventing portion 2 a where the boss portion 6 is formed. Is formed.

An annular stopper 9 facing inward is provided at the left end in the annular recess 8. A substantially C-shaped radially elastically deformable claw ring 10 having a part cut off in the circumferential direction is housed in the annular concave portion 8, and a blade portion 11 having a sawtooth cross section is provided on an inner circumferential surface thereof. Is formed.

The outer peripheral surface of the right end of the claw ring 10 has a tapered surface having the same inclination as the pressing surface 7 of the annular concave portion 8 and an outer diameter slightly smaller than the maximum inner diameter of the pressing surface 7.
Are formed.

The claw ring 10 is formed of a synthetic resin (for example, a polyamide resin) that is harder than the fluid pipe 3 and is elastically deformable, and has a width dimension capable of moving in the pipe axis direction in the annular recess 8. When in contact with the annular stopper 9, a gap is formed between the pressing surface 7 of the separation preventing portion 2 a and the inclined surface 12 of the claw ring 10. Claw ring 1
On the outer peripheral surface of the left end of No. 0, that is, the flat outer peripheral surface facing the push bolt 5, a backing plate 13 made of hard metal is fitted.

In the detachment preventing pipe joint 1 having the above-mentioned structure, the end of the fluid pipe 3 is first brought to the vicinity of the center of the pipe joint body 2 with the claw ring 10 reduced in diameter and housed in the annular groove 8 in advance. insert.

Then, with the left end surface of the claw ring 10 in contact with the annular stopper 9, the push bolts 5 are evenly tightened, and the claw ring 10 is pressed to slightly move the blade portion 11 of the outer periphery of the fluid pipe 3. Into the surface to make the initial bite state (Fig. 1
State).

In this state, a pulling force acts on the fluid pipe 3,
When it is relatively small, slippage occurs at the contact surface between the tip of the push bolt 5 and the backing plate 13, and the claw ring 10 moves rightward with the fluid pipe 3 in the initial bite state,
The inclined surface 12 comes into contact with the pressing surface 7 of the separation preventing portion 2a and stops. Accordingly, when the pull-out force is small, the detachment of the fluid pipe 3 is prevented only by the initial pressing force by the push bolt 5, that is, the initial bite amount.

In the state where the inclined surface 12 of the claw ring 10 is in contact with the pressing surface 7, when a larger pulling force is applied, as shown in FIG. 2, the inclined surface 12 is strongly pressed against the pressing surface 7. The diameter of the claw ring 10 is reduced, and the amount of bite of the blade portion 11 into the fluid pipe 3 increases. As a result, the effect of preventing separation of the fluid pipe 3 is increased.

FIG. 3 shows a modification of the claw ring.
The claw ring 14 of this embodiment has a width in the tube axis direction slightly larger than that described above, and two ends on the inner peripheral surface thereof.
The two blade portions 15a and 15b are formed, and the width of the tapered inclined surface 16 on the outer peripheral surface is increased. The same contact plate 13 as described above is fitted on the surface of the claw ring 14 facing the push bolt 5, and the tip of the push bolt 5 is spherical.

In this embodiment, if only the inner blade portion 15a is bitten into the fluid pipe 3 at the time of construction so as to be in the initial bite state, when the pull-out force is relatively small, the claw ring 14 can be cut as described above. By moving the right end of the inclined surface 16 to a position where the right end of the inclined surface 16 comes into contact with the pressing surface 7, separation of the fluid pipe 3 can be prevented only by initial biting of the inner blade portion 15 a.

When a larger pulling force is applied from this state, as shown in FIG. 4, the entire inclined surface 16 of the claw ring 14 is strongly pressed against the pressing surface 7 so that the claw ring 14 is pressed.
Is reduced in diameter on the right end side, and the outer blade portion 15 b also cuts into the outer peripheral surface of the fluid pipe 3. As a result, the restraining force of the fluid pipe 3 increases, and a large separation preventing effect is exhibited.

When the blade 15b bites, the claw ring 14 slightly turns inward about the tip of the push bolt 5, but the tip of the push bolt 5 has a spherical surface so that it can be rotated without resistance. Can move.

The present invention is not limited to the above embodiment, but can take various embodiments. For example, the blade portions 11, 15a, 15b on the inner peripheral surfaces of the claw rings 10, 14 may be formed by projecting a plurality of annular projections at predetermined intervals in addition to a sawtooth cross section, or by randomly projecting spot-like projections. May be provided. When the claw rings 10 and 14 are formed of a high-hardness synthetic resin material, the backing plate 13 fitted to the outer peripheral surface thereof is used.
May be omitted.

The present invention can be applied not only to the separation of the fluid pipes 3 and 4 made of the above synthetic resin but also to a fluid pipe made of iron (for example, a cast iron pipe or a steel pipe). The claw rings 10 and 14 may be made of metal.

[0028]

According to the present invention, the following effects can be obtained.

(A) According to the first aspect of the present invention, unlike the related art, the blade portion of the claw ring does not bite at the same time as the withdrawal of the fluid pipe, and when the withdrawal force is relatively small, the claw ring is not used. Can move together with the fluid pipe in the initial biting state by the initial pressing force until the inclined surface comes into contact with the pressing surface, so that even if the fluid pipe is made of synthetic resin or the like, a large biting groove is formed on the outer peripheral surface thereof. There is no fear. In addition, when a large pulling force is applied, the inclined surface of the claw ring is strongly pressed against the pressing surface, and the bite amount of the blade portion is increased, so that the effect of preventing the fluid pipe from being detached is large.

(B) According to the second aspect of the invention, when a large pulling force acts on the fluid pipe, the outer blade portion of the claw ring also bites into the outer peripheral surface of the fluid pipe, so that a large separation preventing effect is obtained. can get.

(C) According to the third aspect of the present invention, when a pulling force is applied, the claw ring can be slightly elastically deformed and bent, so that even a fluid pipe made of synthetic resin has an outer peripheral surface. No large digging groove is formed.

(D) According to the fourth aspect of the invention, even with the claw ring made of synthetic resin, the outer peripheral surface with which the push bolt abuts is prevented from being worn.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing one embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a detachment prevention unit when a pulling force is applied.

FIG. 3 is an enlarged cross-sectional view of a separation preventing portion in an initial bite state according to another embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of the separation preventing portion when a pulling force is applied.

FIG. 5 is a longitudinal sectional side view of a main part showing a conventional detachment prevention structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detachment prevention pipe joint 2 Pipe joint main body 2a Detachment prevention part 3, 4 Fluid pipe 5 Push bolt 6 Boss part 7 Pressing surface 8 Annular concave part 9 Annular stopper 10, 14 Claw ring 11, 15a, 15b Blade part 12, 16 Inclined surface 13 Patch plate

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Minoru Ichikawa 2-1-1, Shinbashi, Minato-ku, Tokyo Room 701, New Shimbashi Building Room 706 Cosmo Machinery Co., Ltd. In-house F-term (reference) 3H015 HA02

Claims (4)

[Claims] An inner peripheral surface is formed at an end of a substantially cylindrical pipe joint body into which a connection end of a fluid pipe can be inserted, and a tapered pressing surface whose diameter gradually decreases in a direction in which the fluid pipe is withdrawn. While forming an annular recess, a plurality of push bolts facing the pipe axis are screwed on the outer peripheral surface of the pipe joint body at the portion where the annular recess is formed, such that the tips project into the annular recess. Inserted, and within the annular recess, having a blade portion on the inner peripheral surface that can bite into the outer peripheral surface of the fluid pipe, the outer peripheral surface facing the push bolt is flat, and the outer peripheral surface of the outer side end is A radially elastically deformable claw ring forming a tapered inclined surface inclined in the same direction as the pressing surface, during the initial bite state pressed by the push bolt, between the pressing surface and the inclined surface. Can be moved in the pipe axis direction so that the required gap is formed A detachable pipe fitting characterized by being housed in a noh. 2. A claw ring having a large width dimension in the tube axis direction, a blade portion formed at both end portions of an inner peripheral surface thereof, and an inner side blade portion in an initial biting state by pressing of a push bolt. 2. The detachable pipe joint according to claim 1, wherein a gap is formed between the inclined surface of the outer peripheral surface and the pressing surface of the annular concave portion, while the groove is cut into the fluid pipe. 3. 3. The fluid pipe according to claim 1, wherein the claw ring is formed of a synthetic resin which is harder than the fluid pipe in the case where the fluid pipe or the outer peripheral surface thereof is formed of a synthetic resin. Separation prevention fitting. 4. The detachable pipe joint according to claim 3, wherein a patch plate made of a hard metal is attached to an outer peripheral surface of the claw ring where the push bolt abuts.