JPH11125373A - Separation preventing coupling due to expansion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a separation preventing effect by providing an receiving opening side end part of a lock ring with a stepped part to be engaging with a lock ring stopping part. SOLUTION: A stepped part 8a is formed on the receiving opening side end part of a lock ring 8, and a projecting part projected on the receiving opening side of the stepped part 8a is formed in such a manner as to support the inner peripheral surface of the receiving opening side connected to a lock ring stop part S from the inner peripheral surface side. When the receiving opening side end part of the lock ring 8 abuts to the lock ring stopping part S by external force applied in the separating direction, the projected inner surface side of the stepped part 8a intrudes into the lock ring stopping part S and the receiving inner surface side connected thereto to support them from the inner surface side. Accordingly, even if the force in the extracting direction is further applied to an insert port 1 from this state to raise the inner surface side of the lock ring stopping part S toward the inner periphery, the stopping part is supported from the inner peripheral side by the stepped part 8a to prevent rising. Further, a phenomenon of turning up or shaving off of the lock ring stopping part S is restrained so as to enhance a separation preventing function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a synthetic resin pipe joint having both expandability and prevention of detachment, particularly when an external force is applied to the joint part in a detachment direction (a direction in which an insertion hole comes out). However, the present invention relates to a joint for preventing expansion and disengagement that has been improved so that a high degree of disengagement prevention effect can be exhibited stably.

[0002]

2. Description of the Related Art As a joint having both elasticity and detachment prevention, for example, a joint having a structure as shown in a sectional view of a main part in FIGS. 7A and 7B is known.

In FIGS. 7 (A) and 7 (B), reference numeral 1 denotes an insertion opening, 2 denotes a reception opening, and a lock ring engaging projection 3 is formed on the outer periphery of the distal end portion of the insertion opening 1; On the side, a chamfered tapered surface 4 is provided. On the other hand, on the inner peripheral surface on the opening side of the receiving port 2, a sealing gasket accommodating portion 5 is provided.
A lock ring accommodating portion 7 is formed on the back side, and a lock ring 8 which is made of a rigid material such as metal and which can be tightened is attached to the lock ring housing portion 7. The cavity portion 9 is formed with an appropriate length (L) to allow movement of the portion in the tube axis direction (left-right direction in the figure).

[0004] The lock ring housing 7 is provided with a tapered surface T whose diameter increases in the direction toward the back of the socket.
The end portion of the receiving portion 7 on the opening side of the receiving opening forms a lock ring hooking portion S, and the insertion port 1 moves to the left (outward direction) so that the left vertical surface of the lock ring hooking projection 3 (hook). When the lock ring 8 is pressed against the lock ring 8 and a force in the opening direction is applied to the lock ring 8 to move further in the removal direction, the lock ring 8 contracts while slightly sliding along the tapered surface T. When the lock ring 8 abuts on the lock ring hook S, the insertion opening 1 is prevented from coming off.

Therefore, with the seal packing 6 mounted on the seal packing housing 5 of the receiving port 2 and the lock ring 8 mounted on the lock ring housing 7, respectively, the tapered surface 4 on the outer periphery of the distal end of the insertion opening 1 is used. In a state in which the lock ring hooking projection 3 at the end of the insertion port 1 is pushed into the inner side of the lock ring 8 (FIG. 7A), the insertion port 1 and the receiving port 2 are sealed with a sealing packing 6.
Is connected in a liquid-tight manner by the sealing action of
Can be inserted in the depth direction of the receptacle 2 by the length of the cavity 9 in the axial direction. On the other hand, the insertion port 1 can be moved in the direction of the arrow from the state of FIG. 7A to cope with the extension of the entire pipeline, but the lock ring retaining projection 3 at the tip thereof contacts the lock ring 8 and When the lock ring 8 comes into contact with the lock ring engaging portion S, the movement in the removal direction is prevented [FIG.
(B)] Here, separation is prevented.

The above-mentioned joint structure has conventionally been made of a metal material such as cast iron. By adopting the receiving / inserting joint structure as described above, the joint structure can be expanded and contracted in the tube axis direction. The detachment of the joint part could be prevented. However, recently, as problems such as weight reduction and cost reduction of the joint material and rusting have been pointed out, there has been a tendency to produce such a joint with a synthetic resin material such as high performance polyethylene. I have.

[0007]

Even if the joint is made of a synthetic resin as described above, if the structure shown in the drawing is used, the joint can exhibit a certain degree of expandability and disengagement prevention. However, it has been confirmed that such a synthetic resin pipe joint causes a new problem due to insufficient rigidity of the material as compared with a metal material.

That is, when a large external force acts on such a synthetic resin pipe joint in the detaching direction due to ground subsidence due to land subsidence or earthquake, etc., it has been experienced that the detachment preventing effect is lost. The reason is considered as follows.

That is, when the above-mentioned detachment prevention joint is made of a synthetic resin, an example of such a joint is shown in FIG. In this figure, the slot 1 and the socket 2
Shall be molded with hard synthetic resin,
As in the example shown in FIG. 7, a lock ring engaging projection 3 is formed on the outer periphery of the distal end portion of the insertion opening 1, and a chamfered tapered surface 4 is provided on the outermost peripheral side of the foremost end. On the other hand, on the inner peripheral surface on the opening side of the receiving port 2, a sealing gasket accommodating portion 5 is provided, and a sealing gasket 6 is attached thereto, and a lock ring accommodating portion 7 is formed on the inner side thereof. A lock ring 8 made of a rigid material is attached, and further on the back side,
A cavity 9 is formed with an appropriate length (L) that allows the distal end to move in the tube axis direction (left-right direction in the figure).

The lock ring housing portion 7 is provided with a tapered surface T whose diameter increases in the direction toward the back side of the receiving port, and the end of the receiving section 7 on the receiving port opening side is formed as a lock ring retaining portion S.
The insertion opening 1 moves to the left (pull-out direction), and the left vertical surface (hook surface) of the lock ring hooking projection 3 comes into contact with the lock ring 8. When a force in the direction toward the mouth opening is applied, the lock ring 8 contracts while slightly sliding along the tapered surface T, and when the lock ring 8 comes into contact with the lock ring engaging portion S, the insertion hole is closed. 1 is configured to be prevented. In the figure, reference numeral 11 denotes a reinforcing rib provided at a plurality of positions (usually about 4 to 8 positions) on the inner peripheral surface, and 12 denotes a stopper for restricting the insertion end of the insertion opening 1. By adopting such a configuration,
It is also effective to increase the rigidity while reducing the weight of the receiving port 2.

However, while various studies are being conducted to put such a synthetic resin expansion / contraction release prevention joint into practical use, such a synthetic resin pipe joint has a large size in the departure direction due to ground subsidence due to land subsidence or an earthquake. When an external force acts,
It has been experienced that the anti-withdrawal effect is lost. Therefore, as a result of conducting various studies to clarify the reason, the following facts were confirmed.

The first reason is that, for example, FIG.
As shown in (B) and (C), the lock ring hooking projection 3 at the distal end of the insertion port 1 is in contact with the lock ring 8 and is prevented from being detached, and further receives an external force in the pull-out direction. When the lock ring hooking projection 3 of the insertion opening 1 cannot withstand the force in the pull-out direction and is deformed and swells in the outer peripheral direction (FIG. 9A), the hooking projection 3 is turned up. 9 (B) and 9 (C)], and eventually a phenomenon occurs in which the effect of preventing separation is lost.

The second reason is that, for example, FIG.
As shown in the cross-sections of the main parts in (B) and (C), the lock ring engaging projection 3 at the distal end of the insertion port 1 comes into contact with the lock ring 8, and the end face of the lock ring 8 on the receiving opening side is the lock ring. When an external force in the pull-out direction is further applied in a state where the lock ring-locking portion S of the accommodating portion 7 is prevented from being detached by being hit against the lock-ring locking portion S, the lock ring-locking portion S becomes unable to withstand the pull-out direction force and is deformed. After swelling in the circumferential direction [FIG.
(A)], the hook S is scraped off so as to be turned up [FIGS. 10 (B) and 10 (C)], and eventually a phenomenon occurs in which the separation prevention effect is lost.

[0014] Such a phenomenon is a peculiar phenomenon observed when a synthetic resin having low strength is used as a constituent material of a pipe joint. It is necessary to improve the problem of insufficient separation prevention due to insufficient strength of the material.

The present invention has been made in view of the above problems, and an object of the present invention is to solve the above-described problem of insufficient detachment prevention, which is observed in a synthetic resin expansion-resistant detachment prevention joint. It is in the point.

[0016]

According to the present invention, there is provided an expansion / contraction release preventing joint which has a seal packing accommodating portion near an open end and a rear side of the seal packing accommodating portion. A synthetic resin receptacle having a tapered surface that expands in diameter from the opening end side to the back side and a lock ring accommodating portion having a lock ring hooking portion on the opening end side of the tapered surface; A synthetic resin insertion port having a lock ring hooking projection on the outer peripheral surface on the tip end side; and a first end face and a lock ring hooking projection that are housed in the lock ring housing section and abut on the lock ring hooking section. An expansion / removal prevention joint having a lock ring made of a material having higher rigidity than the synthetic resin, the joint having a second end face to be in contact with, and (a) at an outer peripheral side of the first end face of the lock ring,
(B) providing a step portion for engaging with the lock ring engaging portion;
(C) forming a groove on the first end face of the lock ring; and (d) forming a groove on the inner peripheral side of the second end face of the lock ring.
A groove is formed in the second end surface of the lock ring to improve the deformation of the lock ring engaging projection or the lock ring engaging portion and the loss of the detachment preventing effect due to the phenomenon of being cut off.

In carrying out the present invention, the configuration of (a) is combined with the configuration of (b) or (d), or the configuration of (b) is combined with the configuration of (a) or (c). The combination of the configurations (1) and (2) is preferable because both the lock ring hooking projection and the lock ring hooking portion can be prevented from being deformed and chipped off due to the phenomenon, and the effect of preventing the lock ring can be further enhanced.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, in the present invention, the strength of the lock ring hooking projection 3 and the lock ring hooking portion S found in the synthetic resin expansion / removal prevention joint is determined by the structure of the lock ring 8. It is characterized by the fact that it is compensated for by improving and the detachment prevention effect is improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings showing one embodiment. However, the present invention is not limited to the following embodiments, but conforms to the preceding and following points. It is, of course, possible to implement the present invention with appropriate modifications within the scope of the invention, and all of them are included in the technical scope of the present invention.

FIG. 1 is a cross-sectional explanatory view exemplifying a joint for preventing expansion and disengagement according to the present invention. The reference numerals in the figure are substantially the same as those in FIG. The characteristic configuration of the present invention in this figure is that the shape of the lock ring 8 is devised, and FIG. 1 (a cross-sectional view of the entire joint).
As shown in FIG. 2 and FIG. 2 (a cross-sectional view of a main part showing the lock ring), the end of the lock ring 8 on the receiving opening side is the first end face A.
Then, a step 8a is formed on the first end face A side, and the protrusion protruding toward the receiving opening side of the step 8a forms an inner peripheral surface on the receiving opening side following the lock ring engaging portion S. It is configured to be supported from the inside. When the contact side of the lock ring 8 with the engaging projection 3 is a second end face B, the second end face B
Is formed so that a protruding portion protruding to the back side of the socket of the step portion 8b encloses the lock ring hooking projection 3 from the outer peripheral direction. Hereinafter, these steps 8a,
8b will be described in detail.

The stepped portion 8a provided on the first end face A of the lock ring 8 used in the present invention is provided on the lock ring engaging portion S when the release prevention joint receives an external force in the release direction.
When the first end surface A of the step a is in contact, the protruding inner surface of the stepped portion 8a enters the lock ring engaging portion S and the inner surface of the receiving port connected thereto as shown in FIG. It is formed so that it does. Therefore, even if a force in the pull-out direction is further applied to the insertion opening 1 from this state and the inner surface side of the lock ring hooking surface S tends to swell in the inner circumferential direction as shown in FIG. As a result, the swelling is prevented because it is supported from the inner peripheral side, and furthermore, the phenomenon in which the above-mentioned engaging portion S is flipped up or scraped off is suppressed, and the detachment prevention function is significantly enhanced.

The stepped portion 8b provided on the second end face B of the lock ring 8 is provided with a lock ring 8 on the lock ring hooking projection 3 of the insertion opening 1 when the release prevention joint receives an external force in the release direction.
When the second end face A of the step abuts, as shown in FIG.
The projecting outer surface side of b is formed so as to cover the lock ring engaging projection 3 and a part of the top surface following the lock ring engaging projection 3 from the outer peripheral side. Therefore, even if a force in the withdrawal direction is further applied to the insertion opening 1 from this state, and the hooking projections 3 tend to swell to the outer peripheral side as shown in FIG. 9, the stepped portion 8b suppresses from the outer peripheral side. The bulging is prevented because of the
The phenomenon of fluttering or scraping is suppressed, and the function of preventing detachment is remarkably enhanced.

FIGS. 4 and 5 are cross-sectional views showing a lock ring 8 used in another embodiment of the present invention and a mounting state of the lock ring 8. In this embodiment, FIGS. As shown, a groove 8x is provided on the first end face A of the lock ring 8, and a groove 8y is also provided on the second end face B.

When the first end face A comes into contact with the lock ring engaging portion S by receiving the external force in the detaching direction, the detachment preventing joint is inserted into the groove 8x as shown in FIGS. 5 (A) and 5 (B). As shown in the cross section of the main part, the synthetic resin of the pipe wall connected to the engaging portion S is prevented from swelling inwardly into the groove 8x. In addition, in the groove 8y, the release prevention joint receives the external force in the release direction so that the lock ring retaining projection 3
When the end face B comes into contact, it penetrates into the groove 8y as shown in the cross section of the main part in FIGS. 5 (A) and 5 (B), and the synthetic resin of the wall portion of the hook projection 3 bulges to the outer surface side. It is configured so as to prevent the user from doing so.

As a result, the phenomenon in which the latch S and the latching projection 3 are turned up or scraped off is suppressed, and the function of preventing detachment is remarkably enhanced. This groove 8
As described above, x and 8y bite into the rising surface of the lock ring hooking surface S or the lock ring hooking projection 3 to prevent the pipe wall from bulging to the inner side or the outer side by the anchor effect. Therefore, the shape, structure, number and the like of the grooves 8x and 8y are not limited at all.

Although the lock ring 8 having both the steps 8a and 8b or the grooves 8x and 8y has been described above, the respective functions have been described individually. When formed from a material, the deformation and the turning-up phenomenon of the lock ring hooking projection 3 and the lock ring hooking portion S proceed in parallel. To prevent them simultaneously, as shown in FIGS. It is desirable that both the step portions 8a and 8b or the grooves 8x and 8y be provided in the lock ring 8. However, in some cases, only one of the steps 8a and 8b is formed on the lock ring 8, and only one side of the lock ring hooking projection 3 and the lock ring hook S is strengthened to enhance the detachment prevention function. It is possible, and they are also included in the technical scope of the present invention.

As described above, according to the present invention, the lock ring 8 is formed with the steps 8a, 8b or the grooves 8x, 8y so that the lock ring hooking projection 3 and / or the lock ring hooking surface S
It has the feature that it prevents the pipe wall part that leads to the turning up or shaving off, so that the effect of preventing detachment is more reliably exhibited, as long as this purpose can be achieved, other than shown Various modifications can be made.

For example, FIGS. 6A and 6B are cross-sectional views showing a main part of another structure of the lock ring 8 used in the present invention, and FIG. Edge A
6B, a groove 8x is formed in the first end face A of the rock cling 8, and a step 8a is formed in the second end face B. FIG. Are formed, and these can be effectively used as a preferable lock ring 8 as a matter of course.

Incidentally, the locking projection 3 which is locked by the lock ring 8 is almost 90 ° C. at the tip of the insertion port 1 in most cases.
The external force in the withdrawal direction is concentrated at the rising corner, and there is a risk that the rising of the latching projection 3 is accelerated. Therefore, to prevent such obstacles,
For example, as shown in FIGS.
It is desirable to reduce the concentration of stress by rounding the rising portion of the lock ring 8. If the corner portion of the lock ring 8 that comes into contact with the rising portion is also rounded with substantially the same curvature, the so-called notch effect is obtained. This is preferable because cracking and the resulting scraping phenomenon can be prevented, and the effect of preventing separation can be further enhanced.

The present invention is constructed as described above. The feature of the present invention is that the lock ring 8 made of a hard material is used as described above.
The stepped portion 8a or the groove 8x suppresses the swelling deformation and the scraping phenomenon of the lock ring hooking projection 3 when the lock ring hooking projection 3 is subjected to an external force in the detaching direction, and / or the inner side of the lock ring hooking surface S. Step 8
The feature is that it is suppressed by the b or the groove 8y so that the effect of preventing the detachment can be more reliably exhibited. Packing storage part 5
The shapes and structures of the seal 6, the seal packing 6, the lock ring housing 7, the lock ring hooking projection 3, and the like can be arbitrarily changed as necessary.

A clamping force by the lock ring 8 and a force in the pulling-out direction are applied to the portion of the hooking projection 3 at the end of the insertion port 1, and a force in the tightening direction is also applied to the area where the seal packing 6 comes into contact. For example, as shown in FIG. 1, stainless steel or stainless steel is provided on the inner surface side of the hooking projection 3 of the insertion opening 1 or the inner surface side of the contact area of the seal packing 6 in order to increase the resistance against the tightening force. Reinforcement by mounting a reinforcing ring 14 or a sleeve 15 made of a hardly deformable material having a higher rigidity than the constituent material of the insertion port 1 such as a metal such as gunmetal, a hard vinyl chloride resin, or a polyphenylene-based resin is the present invention. Is recommended as a preferable mode for practical use.

The reinforcing ring 14 and the sleeve 15
May be formed separately, or may be formed integrally. These may be mounted in a molding die in advance when forming the insertion opening 1 and integrated by insert molding, or they may be mounted later on the insertion opening formed in advance. If you want to install it after the fact,
A ring-shaped or short tube with slits provided in the axial direction for easy mounting, and inserted into the inner surface of the insertion port 1 with its diameter reduced, and adhered to the inner surface of the insertion port by elastic force Is also effective.

[0033]

According to the present invention, a step or a groove is formed on the first end face of the lock ring used for the expansion / removal prevention joint on the side of the receiving opening, and / or
Steps or grooves are formed on the second end face on the back side of the receiving end of the lock ring, and a phenomenon in which the lock ring hooking projection 3 and / or the lock ring hooking surface S are swollen or scraped off by the steps or grooves. By suppressing it, the detachment prevention effect can be more reliably exerted.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a typical embodiment of a joint for preventing expansion and disengagement according to the present invention.

FIG. 2 is an explanatory cross-sectional view of a main part illustrating a lock ring used in the present invention.

FIG. 3 is an explanatory cross-sectional view of a main part for describing an effect of a lock ring used in the present invention.

FIG. 4 is an explanatory sectional view of a main part showing a modification of the lock ring used in the present invention.

FIG. 5 is an explanatory sectional view of a main part showing a state where the lock ring shown in FIG. 4 is deformed by receiving a force in a detaching direction.

FIG. 6 is an explanatory cross-sectional view of a main part illustrating another lock ring used in the present invention.

FIG. 7 is an explanatory cross-sectional view of a main part illustrating a conventional cast expansion / contraction release prevention joint.

FIG. 8 is an explanatory cross-sectional view of a main part illustrating a synthetic resin expansion / contraction preventing joint considered by the present inventors.

FIG. 9 is an explanatory sectional view of a main part for describing a problem pointed out in the expansion / removal prevention joint made of synthetic resin as shown in FIG. 8;

FIG. 10 is a cross-sectional view of a main part for explaining another problem pointed out by the synthetic resin expansion / removal prevention joint as shown in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insertion opening 2 Reception opening 3 Lock ring latching projection 4 Tapered surface 5 Seal packing accommodation part 7 Lock ring accommodation part 6 Seal packing 8 Lock ring 8a, 8b Stepped part 8x, 8y Groove 9 Cavity part 11 Reinforcement rib 12 Stopper 14 Reinforcement ring 15 Sleeve

Claims (8)

[Claims] 1. A taper surface having a seal packing accommodating portion in the vicinity of an opening end, and a taper surface increasing in diameter from the opening end side to the back side further from the seal packing accommodating portion. A synthetic resin receptacle having a lock ring receiving portion having a lock ring retaining portion on the opening end side, a synthetic resin insertion port having a lock ring retaining projection on a distal end side outer peripheral surface, and the lock. A lock ring, which is housed in a ring housing portion and has a first end surface abutting on the lock ring hook portion and a second end surface abutting on the lock ring hook protrusion, is made of a material having a higher rigidity than the synthetic resin. The expansion / contraction / separation prevention joint provided, further comprising a stepped portion that engages with the lock ring engaging part on an outer peripheral side of the first end surface of the lock ring. 2. A taper surface having a seal packing receiving portion near an opening end, and a taper surface increasing in diameter from the opening end side to the back side further from the seal packing receiving portion, the taper surface being provided at a position deeper than the seal packing receiving portion. A synthetic resin receptacle having a lock ring receiving portion having a lock ring retaining portion on the opening end side, a synthetic resin insertion port having a lock ring retaining projection on a distal end side outer peripheral surface, and the lock. A lock ring, which is housed in a ring housing portion and has a first end surface abutting on the lock ring hook portion and a second end surface abutting on the lock ring hook protrusion, is made of a material having a higher rigidity than the synthetic resin. The telescopic disengagement prevention joint according to claim 1, further comprising: a step portion on the inner peripheral side of the second end surface of the lock ring, the step part engaging with the lock ring engaging projection. 3. A taper surface having a seal packing receiving portion near an opening end, and a taper surface increasing in diameter from the opening end side to the back side further from the seal packing receiving portion. A synthetic resin receptacle having a lock ring receiving portion having a lock ring retaining portion on the opening end side, a synthetic resin insertion port having a lock ring retaining projection on a distal end side outer peripheral surface, and the lock. A lock ring, which is housed in a ring housing portion and has a first end surface abutting on the lock ring hook portion and a second end surface abutting on the lock ring hook protrusion, is made of a material having a higher rigidity than the synthetic resin. The expansion / contraction / separation prevention joint provided, wherein a groove is formed in the first end surface of the lock ring. 4. A taper surface having a seal packing receiving portion near an opening end, and a taper surface increasing in diameter from the opening end side to the back side further from the seal packing receiving portion. A synthetic resin receptacle having a lock ring receiving portion having a lock ring retaining portion on the opening end side, a synthetic resin insertion port having a lock ring retaining projection on a distal end side outer peripheral surface, and the lock. A lock ring, which is housed in a ring housing portion and has a first end surface abutting on the lock ring hook portion and a second end surface abutting on the lock ring hook protrusion, is made of a material having a higher rigidity than the synthetic resin. The expansion / contraction / separation prevention joint provided, wherein a groove is formed in the second end surface of the lock ring. 5. The joint according to claim 1, wherein a stepped portion is formed on an inner peripheral side of the second end face of the lock ring so as to be engaged with the lock ring retaining projection. 6. The joint according to claim 1, wherein a groove is formed in the second end face of the lock ring. 7. The joint according to claim 2, wherein a groove is formed in the first end face of the lock ring. 8. The joint according to claim 3, wherein a groove is formed in the second end surface of the lock ring.