JP3657920B2 - Pipe joint structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe joint structure for connecting a pipe made of synthetic resin to a metal pipe, a metal valve or the like.
[0002]
[Prior art]
Centrifugal casting pipes made of ductile cast iron are mainly used as water supply pipes for tap water etc. buried underground, but in recent years, inexpensive synthetic resin pipes have gradually been used and their flexibility Is attracting attention as a safe conduit. In particular, polyethylene pipes are attracting attention and are showing signs of rapid spread. In addition, the use of resin pipes is expanding not only in the field of water supply pipes but also in the field of gas pipes and sewage pipes.
[0003]
On the other hand, more than 95% of water supply pipes have been developed at present, and the number of new pipes is declining. However, it is now time to replace the cloth with aging, and at that time, the existing ductile cast iron pipe and a resin pipe (for example, polyethylene pipe) are often connected. In addition, in the water supply piping installed over the hills, resin pipes can be used in the low pressure part such as the top, but ductile cast iron pipes are required in the high pressure part such as the valleys, and the connection between the cast iron pipe and the resin pipe May occur. Furthermore, when installing valves and fire hydrants directly in the pipe line of resin pipes or via T-shaped pipes, from the strength aspect, use these metal parts for these valves, fire hydrants and T-shaped pipes. In many cases, connection between the pipe portion and the resin pipe is required.
[0004]
As a pipe joint structure for connecting a resin pipe to a metal pipe, a metal valve or the like, for example, there is one described in JP-A-10-132168. As shown in FIG. 8, this pipe joint structure includes a lock ring 52 having a tapered outer surface and a toothed portion on the inner surface, and an inner surface on the outer surface of the lock ring 52. A collar ring 53 formed into a tapered shape, a seal member 54, a washer 55, and a press ring 56 that presses the seal member 54 through the washer 55 are incorporated, and the press ring 56 is connected to a bolt 57 and a nut 58. It is fastened to the receiving port 59a of the ductile cast iron pipe 59. The seal member 54 includes a backup ring 54a, a round rubber ring 54b, and a square rubber ring 54c.
[0005]
That is, in this pipe joint structure, the press ring 56 is tightened with the bolt 57 and the nut 58, and the color ring 53 is moved to the end side of the opening 51 a through the washer 55 and the seal member 54 by the press ring 56. By reducing the diameter of the lock ring 52 and causing its teeth to bite into the resin pipe 51, the resin pipe 51 is prevented from being detached from the cast iron pipe 59. Note that an inner core 60 is fitted on the inner peripheral surface of the resin tube 51 in order to suppress deformation of the resin tube 51 due to the reduced diameter of the lock ring 52 and improve the biting of the lock ring 52.
[0006]
[Problems to be solved by the invention]
In the conventional pipe joint structure described above, since the round rubber ring 54b and the square rubber ring 54c having large elasticity are interposed between the lock ring 52 and the push ring 56, the lock ring 52 is bitten by the tightening amount of the push ring 56. Is difficult to adjust, and there is a possibility that the resin tube 51 cannot be prevented from being detached due to insufficient bite. Further, the tightening of the push wheel 56 may become uneven in the circumferential direction, and the round rubber ring 54b and the square rubber ring 54c may be twisted, and the sealing performance may be deteriorated.
[0007]
In addition, since the number of parts is large, there is a problem that work mistakes such as forgetting to put in parts and wrong insertion direction are likely to occur.
[0008]
Therefore, an object of the present invention is to provide a pipe joint structure that can reliably prevent the resin pipe from being detached with a simple configuration and is excellent in sealing performance.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention provides a pipe joint structure in which a resin pipe insertion port is inserted into a receiving port of an opposite pipe with a seal member interposed therebetween, and a mechanism for preventing the resin pipe from being detached is provided. the detachment prevention mechanism of the resin tube, the closer to the socket end of the seal member, the have a substantially same inner diameter as the outer diameter of the resin pipe, the inner circumference side to an expandable and contractible diameter teeth provided wedge across the ring, and junk ring having a slightly smaller inner diameter than the outer diameter of the wedge ring, incorporate a pushing ring with an inner diameter smaller than the outer diameter of the wedge ring to face each other, the junk ring and the pushing ring and entered into to attract each other, is pushed on the inner periphery of the pressing ring at the inner periphery of the push ring wedge ring is reduced in diameter, by cutting into the outer peripheral surface of the inserted port of the resin pipe, the Yuck Ring, a flange portion made of a junk ring and push ring integrated with the resin pipe was assumed that a force in a direction to pull the resin pipe provided with retaining portion for locking the collar portion when acting on the receptacle It is.
[0010]
That is, a wedge ring, a push ring and a push ring incorporated in a position closer to the receiving end than the seal member are integrated with the resin pipe by biting the wedge ring into the outer peripheral surface of the insertion opening of the resin pipe, By providing the stopper with a retaining portion that locks the collar when a force in the direction of pulling out the resin tube is applied to the receiving port, the detachment prevention mechanism is configured independently of the seal member having a large elasticity, so that the wedge ring is In order to ensure the integrity of the collar portion and the resin pipe, the separation of the resin pipe can be surely prevented, and the sealing performance is also maintained well.
[0011]
By providing the retaining portion with the function of the push ring or push ring, the number of parts can be further reduced.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5 show a first embodiment. In this pipe joint structure, as shown in FIG. 1, an insertion port 1a of a synthetic resin tube 1 made of polyethylene is inserted into a receiving port 2a of a facing ductile iron pipe 2 with a rubber ring 3 as a seal member interposed therebetween. When the force in the direction of pulling out the resin tube 1 is applied due to an earthquake or the like, the flange 4 integrated with the resin tube 1 is connected to the end of the receiving port 2a. The resin pipe 1 is prevented from detaching by being locked by a retaining member 6 inserted from the hole 5.
[0013]
The rubber ring 3 is positioned by being fitted into a protrusion 2b provided on the inner peripheral side of the receiving port 2a, and is pressed by the outer peripheral surface of the insertion port 1a and the inner peripheral surface of the receiving port 2a to be self-sealing mechanism. To stop the water. In addition, the protrusion which positions the rubber ring 3 can also be provided in the insertion port 1a outer peripheral side. Further, a positioning groove may be provided on the outer peripheral surface of the insertion port 1a or the inner peripheral surface of the receiving port 2a, and the rubber ring 3 may be fitted into this groove.
[0014]
As shown in FIGS. 2A and 2B, the flange portion 4 includes a wedge ring 7, a push ring 8, and a push ring 9 (hereinafter referred to as a three-point member), and the push ring 8 and the push ring 9. Are fastened by bolts 10 at four locations in the circumferential direction.
[0015]
The wedge ring 7 is made of engineering plastic and has an inner diameter that is approximately the same as the outer diameter of the resin tube 1, with teeth on the inner peripheral side and tapered toward the end of the receiving port 2 a on the outer peripheral side. Each of the tapered surfaces is provided. Moreover, one place in the circumferential direction is cut off, and the diameter can be increased and decreased. The material of the wedge ring 7 is rigid enough to maintain the integrity with the resin tube 1 even when the pulling force acts on the resin tube 1 and the collar 4 is locked by the retaining member 6. Any material that can be slightly expanded and contracted may be used.
[0016]
The pusher wheel 8 is made of stainless steel, and has holes 8a through which bolts 10 are passed at equal intervals in four locations in the circumferential direction. The hole 8a is formed with a counterbore portion having a depth into which the head of the bolt 10 is fitted, and when the collar portion 4 is locked to the retaining member 6, the presser wheel 8 is retained on the end surface. No stress concentration occurs in contact with 6.
[0017]
Further, on the inner peripheral side of the push wheel 8, tapered surfaces that are tapered toward the end of the receiving port 2a are provided at two locations in the axial direction. Among these, the tapered surface on the back side of the receiving port 2a is for smoothly receiving the wedge ring 7 on the inner periphery, and the tapered surface on the end side of the receiving port 2a is for positioning the received wedge ring 7 It is. The inner diameter of the central portion sandwiched between both tapered surfaces is formed to be slightly smaller than the outer diameter of the wedge ring 7 so that the wedge ring 7 is reduced in diameter.
[0018]
The pushing ring 9 is made of stainless steel, and is provided with screw holes 9a that are coupled to the threaded portions of the bolts 10 at four equal intervals in the circumferential direction. The inner diameter is smaller than the outer diameter of the wedge ring 7 so that the wedge ring 7 can be pushed into the inner periphery of the push ring 8 at the inner peripheral edge of the end face when the bolt 10 is fastened to the push ring 8.
[0019]
The push ring 8 and the push ring 9 are preferably made of stainless steel as described above, but can also be formed using a material having strength and corrosion resistance such as engineering plastic. In addition, in order to reduce the weight and improve the workability, the outer diameter and the thickness can be suppressed by avoiding the increase in the bolt diameter by increasing the number of bolts for the large diameter pipe. Good.
[0020]
These three-point members 7, 8, and 9 are joined together as shown in FIG. That is, first, as shown in FIG. 3 (a), the push ring 8 and the push ring 9 are arranged so as to face each other with the wedge ring 7 interposed therebetween, and passed through the push ring 8 as shown in FIG. 3 (b). When the bolt 10 is screwed to the push ring 9 and tightened, the push ring 8 and the push ring 9 are pulled together, and the wedge ring 7 is pushed into the inner periphery of the push ring 8 at the inner peripheral edge of the inner end face of the push ring 9. At this time, since the tapered surface is formed at both the pushing side end of the wedge ring 7 and the receiving side end of the push ring 8, the wedge ring 7 is smoothly guided to the inner periphery of the push ring 8. Then, the bolt 10 is further tightened, and the tapered surface is engaged with the tapered surface on the other end side of the press wheel 8 while the wedge ring 7 is contracted by the press wheel 8 as shown in FIG. Position.
[0021]
By connecting the three-point members 7, 8, 9 at the positions shown in FIG. 1 as described above, the inner peripheral teeth of the wedge ring 7 having a reduced diameter are attached to the outer peripheral surface of the insertion opening 1 a of the resin tube 1. It is possible to integrate the flange portion 4 formed of the three-point members 7, 8, 9 with the resin tube 1 independently of the rubber ring 3.
[0022]
An inner core 11 having an outer diameter substantially equal to the inner diameter of the resin tube 1 is fitted on the inner peripheral surface of the resin tube 1 to a position where the wedge ring 7 bites in from the tube end. The deformation of the resin tube 1 when the diameter is reduced is suppressed, and the wedge ring 7 is bitten, so that the unity between the resin tube 1 and the flange portion 4 is improved. The fitting depth of the inner core 11 may be anywhere as long as it is deeper than the position of the wedge ring 7.
[0023]
As shown in FIG. 4, the retaining member 6 is composed of retaining pieces 6a divided into a plurality in the circumferential direction, and the retaining members 6a are dropped one by one from the through holes 5 at the end of the receiving port 2a one by one. Then, by fitting into the annular groove 2c communicating with the through hole 5 of the receiving port 2a, the flange 4 integrated with the resin tube 1 is set to be locked. After fitting the retaining pieces 6a, the through holes 5 are plugged so that foreign matter such as earth and sand does not enter the grooves 2c. Note that the number of divisions of the retaining pieces 6a is preferably small in order to make the force acting when locking the collar part 4 more uniform, but if the number of divisions is small, the through-hole 5 becomes large. In this case, the receiving port 2a may be reinforced.
[0024]
That is, in this pipe joint structure, the flange portion 4 that is integrated with the resin pipe 1 and is prevented from being detached when a pulling force acts on the resin pipe 1 is located closer to the end of the receiving port 2a than the rubber ring 3 for sealing. In this way, the detachment prevention mechanism for the resin tube 1 is configured independently of the rubber ring 3 having large elasticity. Therefore, the wedge ring 7 can be sufficiently bitten into the resin tube 1 when forming the flange portion 4, and the integrity of the flange portion 4 and the resin tube 1 can be ensured, and the resin tube 1 can be reliably detached. Can be blocked. Further, the rubber ring 3 is not affected by the formation of the flange portion 4, and the sealing performance is maintained well.
[0025]
In the example shown in FIG. 1, among the three-point members 7, 8, and 9 that form the flange portion 4, the push wheel 8 is disposed on the end side of the receiving port 2 a and the push ring 9 is disposed on the back side of the receiving port 2 a. However, this arrangement can be reversed. In that case, it is only necessary to provide a bolt through hole in the push ring and a screw hole to be coupled to the bolt in the push ring, and to provide the tapered surfaces of the push ring and the wedge ring in opposite directions.
[0026]
Further, as the sealing member, an O-ring 13 can be used as shown in FIG. In this example, O-rings 13 are attached at two axial positions so that the insertion port 1a can be inserted straight into the receiving port 2a. Further, the positioning groove of the O-ring 13 is provided on the resin pipe 1 side, but may be provided on the cast iron pipe 2 side.
[0027]
The above-described arrangement of the three-point members and the deformation of the seal mechanism are the same for the second and third embodiments described later.
[0028]
Next, the construction procedure for connecting the resin pipe 1 and the cast iron pipe 2 with this pipe joint structure will be described. As a construction procedure, first, the three-point members 7, 8, 9 are attached to the insertion opening 1 a of the resin tube 1, and are joined to the resin tube 1 while being joined as shown in FIG. Then, the insertion port 1a is inserted into the receiving port 2a, and finally the retaining member 6 is inserted from the through hole 5 at the end of the receiving port 2a. Seal members such as the rubber ring 3 and the O-ring 13 are previously attached to the insertion port 1a or the receiving port 2a. In this method, since the three-point members 7, 8, and 9 can be joined while visually observing, the construction is simple.
[0029]
Alternatively, the three-point members 7, 8, and 9 can be preliminarily assembled in the receiving port 2a in a temporarily fixed state, and the bolt 10 can be tightened and joined after the insertion port 1a is inserted into the receiving port 2a at the construction site. . In that case, what is necessary is just to attach | subject the mark of the bolt 10 fastening position in which the three-point members 7, 8, and 9 will be in an appropriate joining state to the insertion port 1a.
[0030]
FIG. 6 shows a second embodiment. In this pipe joint structure, the flange portion 4 including the three-point members 7, 8, and 9 is locked by the protruding portion 14 provided on the inner peripheral side of the end portion of the receiving port 2 a. The projecting portion 14 is adapted to insert the notch 14a to the position of the upper and lower opposing two locations is formed, the pressing ring 8 and pusher ring 9 through the cutout 14a into the socket in 2a. The inserted push ring 8 and push ring 9 are inverted in the receiving port 2a, set at a predetermined position, bent and joined together with the wedge ring 7 inserted therebetween. The configuration of the other parts is the same as that of the first embodiment. In this embodiment, since the inserted three-point members 7, 8, and 9 do not come off from the receiving port 2a, they can be temporarily assembled at the factory and shipped.
[0031]
Note that the push wheel 8 and the push ring 9 may be divided in the circumferential direction in order to facilitate insertion into the receiving port 2a. Although the number of divisions is arbitrary, it is preferable that the number of divisions is small in terms of uniformity of force acting when locked to the protruding portion 14 and ease of management.
[0032]
FIG. 7 shows a third embodiment. In this pipe joint structure, the protruding portion 15 is formed in the same shape as the push ring 8 of the first and second embodiments by forming the protruding portion 15 as a retaining portion provided on the inner peripheral side of the end portion of the receiving port 2a. To which the function of a push ring is added. The structure of other parts is the same as that of the second embodiment, and the pushing ring 9 is inserted from a notch not shown in the projection 15. In this embodiment, a push wheel is not required, and the number of parts can be reduced.
[0033]
Similarly, when the arrangement of the three-point members is reversed as described above, the number of parts can be reduced by adding a function of a pushing ring to the protruding portion of the receiving end.
[0034]
The present invention can be applied not only to the case where the insertion port of the resin pipe is inserted into the receiving port of the cast iron pipe and connected as in the above-described embodiments, but also to the connection of the resin pipes.
[0035]
【The invention's effect】
As described above, the pipe joint structure according to the present invention integrates the flange portion composed of the wedge ring, the push ring, and the push ring that are incorporated closer to the receiving end than the seal member with the resin pipe. Since the stopper is provided with a retaining portion that locks the flange when the pulling force is applied, and the resin tube detachment prevention mechanism is configured independently of the seal member, the flange and the resin tube The integrity can be ensured and the resin tube can be reliably prevented from detaching, and the sealing performance is also maintained well.
[0036]
Moreover, the number of parts can be further reduced by providing the retaining portion with a function of a push ring or a push ring.
[Brief description of the drawings]
FIG. 1 is a front sectional view of a pipe joint structure according to a first embodiment. FIG. 2 is a side view and a front sectional view showing the structure of a buttock of the pipe joint structure of FIG. a, b, and c are front cross-sectional views illustrating the formation process of the flange portion in the pipe joint structure of FIG. 1, respectively. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 6 is a front sectional view of a pipe joint structure according to a second embodiment. FIG. 7 is a front sectional view of a pipe joint structure according to a third embodiment. 8] Front sectional view of conventional pipe joint structure [Explanation of symbols]
1 resin pipe 1a inserted port 2 cast iron pipe 2a receptacle 2b projections 2c annular groove 3 rubber ring 4 flange portion 5 through hole 6 retaining member 6a retaining piece 7 wedge ring 8 junk ring 8a hole 9 pushing ring 9a threaded hole 10 bolt 11 Inner core 12 Plug 13 O-ring 14 Protruding part 14a Notch 15 Protruding part

Claims (2)

In the pipe joint structure provided with a mechanism for preventing the resin tube from being detached by inserting the resin tube insertion port into the opposite tube receiving port with a seal member interposed therebetween, the resin tube removal preventing mechanism includes the seal member. at a position closer to the socket end than, said generally have a same inner diameter as the outer diameter of the resin pipe, across the scaled size capable wedge ring teeth provided on the inner peripheral side than the outer diameter of the wedge ring A push ring having a slightly smaller inner diameter and a push ring having an inner diameter smaller than the outer diameter of the wedge ring are assembled so as to face each other , and the push ring and the push ring are fastened so as to draw each other, thereby push the inner periphery of the push ring on the inner periphery of the pressing ring is reduced in diameter, by cutting into the outer peripheral surface of the inserted port of the resin tube, the wedge ring, the pressing ring and the pushing ring Tona A pipe joint structure characterized in that a flange part is integrated with a resin pipe, and a retaining part for locking the flange part when a force in a direction of pulling out the resin tube is applied is provided in the receiving port. . The pipe joint structure according to claim 1, wherein a function of the push ring or the push ring is provided to the retaining portion.

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