JP2015158214A - Pipe joint structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint structure capable of securing a range to adjust a length of a connected pipe by a joint, by shortening a connection space of an end portion of the connected pipe, and improving workability in replacement work from a cast-iron pipe to a polyethylene pipe.SOLUTION: In a pipe joint structure connecting a connection joint member 2 to an end portion of a polyethylene pipe 1, and including slip-off preventing means 4, the slip-off preventing means 4 includes: a slip-off preventing member 5 inserted into the end portion of the polyethylene pipe 1; a sealing member 6 inserted into a clearance (M) between an inner peripheral face of an end portion of the connection joint member 2 and an outer peripheral face of the end portion of the polyethylene pipe 1; a locking member 7 inserted into between the sealing member 6 and the slip-off preventing member 5 in the clearance (M); and a pressing mechanism 8 for pressing the sealing member 6 to reduce a diameter of the polyethylene pipe 1 thereby pressing an inner peripheral face of the polyethylene pipe 1 to an outer peripheral face of the slip-off preventing member 5.

Description

  The present invention can ensure a range in which the length of the pipe to be connected can be freely adjusted by shortening the connection space of the pipe end portion of the pipe to be connected, in particular, the pipe to be connected. The present invention relates to a pipe joint structure capable of improving workability in replacement work from a cast iron pipe to a polyethylene pipe.

  As a conventional joint structure for connecting a polyethylene pipe and a cast iron pipe, a mechanical joint structure as shown in FIG. 5 is known.

  This joint structure connects the polyethylene pipe 21 and the cast iron pipe 22 via a mechanical joint part 24 having a flange 23 provided at the end of the cast iron pipe 22. A reinforcing member 25 is driven into the end portion of the polyethylene tube 21 to increase the rigidity of the end portion of the polyethylene tube 21, and a stopper that includes a lock ring 26 and a color ring 27 is provided on the outer periphery of the end portion. A ring 28 is attached.

  Further, a backup ring 30, a round rubber ring 31, a square rubber ring 32, a washer 34, and a push ring 29 are mounted in this order adjacent to the back side of the polyethylene pipe 21 from the retaining ring 28. With each member mounted in this manner and the polyethylene pipe 21 being inserted into the mechanical joint portion 24, the bolt hole 23 a of the flange 23 and the bolt of the push wheel 29 are pushed so that the washer 34 is pushed by the rib portion of the push wheel 29. The polyethylene pipe 21 and the cast iron pipe 22 are connected by tightening the bolt 35 through the hole 29a with the nut 36 (see Patent Document 1).

JP-A-10-132168

  The mechanical joint structure described above has the following problems.

  (1) A space for attaching a retaining ring 28 (lock ring 26, color ring 27) to the outer periphery of the end of a connection target pipe (for example, polyethylene pipe 21), a backup ring 30, and a rubber ring 33 (round rubber ring 31). , A rubber band 32), a space for arranging sealing members such as a washer 34 is required. For this reason, the space required to connect from the pipe end of the pipe to be connected along the pipe axis becomes long, and since there are many parts necessary for connection, it takes time to connect, so good workability could not be obtained. .

  (2) When replacing pipes, it is necessary to temporarily connect the old and new pipes to be connected (temporary piping). At this time, the depth of the old and new pipes buried from the ground surface They are not necessarily the same. In this case, since it becomes necessary to adjust the difference in the embedment depth with temporary piping, each time temporary piping is performed, there is no choice but to create a new temporary piping each time. It took time, effort and expense.

  (3) When a pull-out force acts on the connection target pipe during an earthquake, etc., the length of the connection target pipe is basically not adjusted in the mechanical joint structure described above. For example, the connection target pipe is made of polyethylene. In the case of a pipe, damage to the polyethylene pipe is inevitable because it corresponds to the withdrawal of the pipe to be connected due to the elongation of the polyethylene material.

  Accordingly, an object of the present invention is to reduce the connection space of the pipe end portion of the connection target pipe in the pipe joint structure for connecting the pipes, thereby adjusting the length of the connection target pipe. It is providing the pipe joint structure which can improve the workability | operativity in the replacement work from a cast iron pipe to a polyethylene pipe by ensuring the range which can be performed with a joint.

  The present invention has been made to achieve the above object, and is characterized by the following.

  The invention according to claim 1 is a pipe joint structure provided with a retaining means for connecting a joint member to an end portion of a connection target pipe, wherein the retaining means is inserted into a pipe end portion of the connection target pipe. A retaining member, a sealing member inserted into a gap formed between an inner circumferential surface of the end of the joint member and an outer circumferential surface of the end of the connection target pipe, and in the gap, The locking member inserted between the sealing member and the retaining member, and the sealing member are pushed in to reduce the diameter of the connection target tube, and thus the inner peripheral surface of the connection target tube is removed. It is characterized by having a pushing mechanism that pushes against the outer peripheral surface of the stopper member.

  According to a second aspect of the present invention, in the first aspect of the present invention, the outer peripheral surface of the retaining member is formed with a convex portion for biting into the inner peripheral surface of the connection target pipe. It has characteristics.

  The invention described in claim 3 is characterized in that, in the invention described in claim 2, the convex portion has a tooth shape formed by two surfaces.

  The invention according to claim 4 is the invention according to claim 3, wherein the convex portion has an insertion side surface of the retaining member and an anti-insertion side surface of the retaining member, The angle of the retaining member with respect to the axis is smaller than the angle of the anti-insertion side surface with respect to the axis of the retaining member.

  The invention according to claim 5 is characterized in that, in the invention according to any one of claims 2 to 4, the convex portion is formed in a spiral shape around the axis of the retaining member. Is.

  The invention described in claim 6 is characterized in that, in the invention described in any one of claims 1 to 5, the end surface of the locking member on the sealing member side is formed in a convex shape. It is what you have.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the push-in mechanism includes a push ring abutting on the sealing member, the push ring and the joint member. It is characterized by comprising a bolt and a nut for fastening.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the joint member connects an end of the connection target pipe and an end of the connection target pipe. It has the characteristics. .

  A ninth aspect is characterized in that, in the invention according to any one of the first to eighth aspects, the sealing member is made of rubber.

  The invention described in claim 10 is characterized in that, in the invention described in any one of claims 1 to 9, the connection object pipe is made of resin.

  The invention described in claim 11 is characterized in that, in the invention described in claim 10, the resin is polyethylene.

  The invention described in claim 12 is characterized in that, in the invention described in claim 8, the connection target pipe is a metal pipe.

  The invention according to claim 13 is characterized in that, in the invention according to claim 8, the pipe to be connected is made of resin.

  According to this invention, the diameter of the connection target tube is reduced by pushing the sealing member, and thus the frictional resistance between the inner peripheral surface of the connection target tube and the outer peripheral surface of the retaining member is increased. Compared with the conventional pipe joint structure in which the retaining ring and the mechanical joint part are arranged side by side on the outer peripheral surface, the length of the space required for connection along the pipe axis from the pipe end of the pipe to be connected can be shortened. . That is, the connection space at the pipe end of the pipe to be connected can be shortened.

  In addition, according to the present invention, the convex portion is formed on the outer peripheral surface of the retaining member, and the inner peripheral surface of the connection target tube is bitten to further prevent the connection target tube into which the retaining member is inserted from being prevented from coming out. Can be increased.

  Further, according to the present invention, by securing a range in which the length of the connection target pipe can be adjusted by the joint, the retaining ring and the mechanical ring are provided on the outer peripheral surface of the connection target pipe as in the conventional pipe joint structure. Since it is not necessary to arrange the joint portion side by side, the number of parts required for connection can be reduced. As a result, the connection work of the pipe joint can be improved.

  Further, according to the present invention, when the pipe is connected, the end of the pipe to be connected is inserted into the inner part of the joint member in advance, so that the embedment depth of the old and new pipes can be reduced during pipe replacement work. Can handle differences. As a result, the temporary pipe can be used repeatedly, so that it is not necessary to prepare a new temporary pipe each time according to the site, and the pipe can be exchanged smoothly.

  Further, according to the present invention, in the event of an earthquake or the like, when a pull-out force acts on the connection target pipe, the adjustment allowance for the length of the connection target pipe is large. It can cope with the withdrawal of the tube.

It is sectional drawing which shows the pipe joint structure of this invention. It is A arrow directional view of FIG. It is the elements on larger scale of a retaining member. It is explanatory drawing of the length adjustment allowance of the pipe for connection by the pipe joint structure of this invention. It is sectional drawing which shows the conventional joint structure.

  Next, an embodiment of the pipe joint structure of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a pipe joint structure of the present invention, FIG. 2 is a view taken along arrow A in FIG. 1, and FIG. 3 is a partially enlarged view of a retaining member.

  1 to 3, reference numeral 1 denotes a polyethylene pipe which is a connection target pipe. The connection target pipe may be a resin pipe other than a polyethylene pipe. 2 is a connection joint member as a joint member. The connection joint member 2 connects the end of the polyethylene pipe 1 and the end of another polyethylene pipe 3 that is a connection target pipe. The pipe to be connected may be a metal pipe such as a cast iron pipe or a steel pipe in addition to the polyethylene pipe 3.

  A protrusion 2a is formed at the axially central portion of the inner peripheral surface of the connection joint member 2, and when the polyethylene pipe 1 is inserted to the back of the connection joint member 2, a flange 5a of the retaining member 5 described later is provided. It contacts the ridge 2a. The connection joint member 2 has such a length that an adjustment allowance (T1) is formed between the flange 5a and a locking member 8 described later when the flange 5a abuts on the protrusion 2a. .

  Reference numeral 4 denotes a retaining means, which comprises a retaining member 5, a sealing member 6, a locking member 7, and a pushing mechanism 8.

  The retaining member 5 has a cylindrical shape and is inserted into the tube end portion of the polyethylene tube 1. One end of the retaining member 5 is formed with a flange 5a that contacts the tube end surface of the polyethylene tube 1, and the outer circumferential surface of the retaining member 5 is formed with a convex portion 5b in the circumferential direction (FIG. 3). reference). The outer diameter of the flange 5 a is larger than the outer diameter of the polyethylene pipe 1, and the locking member 7 is brought into contact with the flange 5 a portion protruding from the outer peripheral surface of the polyethylene pipe 1.

  The convex part 5b is formed in a tooth shape by two surfaces, and as shown in FIG. 3, the angle (θ2) of the insertion side surface (S2) of the convex part 5b with respect to the axis of the retaining member 5 is the anti-insertion side surface (S1 ) With respect to the axis of the retaining member 5 (θ1). By forming the convex portion 5b in this way, it is easy to insert the retaining member 5 into the end portion of the polyethylene tube 1, while the convex portion 5b is formed into the polyethylene tube 1 due to the reduced diameter of the polyethylene tube 1 as described later. After biting into the inner peripheral surface, the polyethylene pipe 1 can be reliably prevented from coming off.

  The protrusions 5b are independently formed with an interval in the axial direction of the retaining member 5, but the protrusions 5b may be formed in a spiral shape around the shaft of the retaining member 5. When the retaining member 5 is inserted into the end portion of the polyethylene pipe 1 by making the convex portion 5b into a spiral shape, even when the insertion is tight, the retaining member 5 is inserted while rotating so that the spiral-shaped portion However, the retaining member 5 can be easily inserted by acting as a screw. Moreover, when removing the retaining member 5, it can be easily removed by the action of a screw.

  The convex portion 5 b is formed when a sufficiently large frictional resistance is obtained between the inner peripheral surface of the polyethylene tube 1 and the outer peripheral surface of the retaining member 5 due to the reduced diameter of the polyethylene tube 1. There is no need.

  The sealing member 6 is made of a rubber ring, and is inserted into the inlet portion (M1) of the gap (M) formed between the inner peripheral surface of the end of the connection joint member 2 and the outer peripheral surface of the end of the polyethylene pipe 1. The The length of the gap obtained by subtracting the inlet portion (M1) from the gap (M) is the same as the length of the adjustment allowance (T1).

  The locking member 7 contacts the sealing member 6, and the end surface of the locking member 7 on the sealing member 6 side is formed in a convex shape. By forming the end face on the sealing member 6 side of the locking member 7 in a convex shape, the reaction force generated in the sealing member 6 when a pressing force acts on the sealing member 6 by a pressing mechanism 8 described later. , It can be efficiently transmitted to the inner peripheral surface of the end portion of the connection joint member 2 and the outer peripheral surface of the end portion of the polyethylene pipe 1. As a result, the sealing performance is improved and the polyethylene pipe 1 can be reliably reduced in diameter. The convex portion may be formed in an annular shape along the circumferential direction of the locking member 7.

  When the sealing member 6 is pushed into the gap (M1) by the pushing mechanism 8, the pushing force causes the outer peripheral surface of the sealing member 6 to be constrained by the connecting joint member 2, so that the diameter of the polyethylene pipe 1 is reduced. It becomes power. When the diameter of the polyethylene tube 1 is reduced, the convex portion 5 b of the retaining member 5 bites into the inner peripheral surface of the polyethylene tube 1.

  The push-in mechanism 8 includes a push ring 9 that is in contact with the sealing member 6, a bolt 10 that fastens the push ring 9 and the connection joint member 2, and a nut 11 that is screwed into the bolt 10. The bolt 10 is inserted into a bolt hole 9 a formed in the push wheel 9 and a bolt hole 2 a formed in the connection joint member 2.

  According to the pipe joint structure of this invention comprised as mentioned above, a connection joint member can be connected to the edge part of a polyethylene pipe as follows.

  As shown in FIGS. 1 and 2, a push ring 9, a sealing member 6, and a locking member 7 are fitted in advance at the back of the pipe end of the polyethylene pipe 1, and the retaining member 5 is inserted into the end of the polyethylene pipe 1. Insert.

  Next, the connection joint member 2 is fitted into the end portion of the polyethylene pipe 1 into which the retaining member 5 is inserted. At this time, the flange 5 a of the retaining member 5 is inserted until it comes into contact with the protrusion 2 a of the connecting joint member 2. In addition, when it is necessary to adjust the length of the connection coupling member 2, it inserts before contacting the protrusion 2a.

  Next, the locking member 7 and the sealing member 6 are placed in the entrance portion (M1) of the gap (M) formed between the inner peripheral surface of the end portion of the connection joint member 2 and the outer peripheral surface of the end portion of the polyethylene pipe 1. The bolt 10 is inserted into the bolt hole 9 a formed in the push wheel 9 and the bolt hole 2 a formed in the connection joint member 2, and the nut 11 is tightened. As a result, the sealing member 6 is pushed into the gap (M1).

  When the sealing member 6 is pushed in, the polyethylene tube 1 is reduced in diameter by the sealing member 6, and the convex portion 5 b of the retaining member 5 bites into the inner peripheral surface of the polyethylene tube 1. As a result, even if a pulling-out force acts on the polyethylene pipe 1, the convex portion 5 b of the retaining member 5 bites into the inner peripheral surface of the polyethylene pipe 1, so that the polyethylene pipe 1 is in contact until the flange 5 a comes into contact with the locking member 7. However, there is no possibility that the polyethylene pipe 1 will come out of the connecting joint member 2 after that.

  As described above, when a pulling-out force is applied to the polyethylene pipe 1, the polyethylene pipe 1 can move until the flange 5a contacts the locking member 7. Therefore, when the pipe is replaced, the polyethylene pipe 1 can be moved. When there is a need to adjust the length, it is not necessary to cut the polyethylene pipe 1 or prepare a new polyethylene pipe 1, so that the pipe can be exchanged smoothly.

  Further, when a pull-out force is applied to the polyethylene pipe 1 during an earthquake or the like, the length for adjusting the length of the polyethylene pipe 1 is large, so that the polyethylene pipe 1 can be pulled out without depending on the elongation due to the material of the polyethylene pipe 1. be able to.

  In this way, the connection joint member 2 can be connected to the end of the polyethylene pipe 1. The pipe to be connected connected to the polyethylene pipe 1 via the connection joint member 2 may be a metal pipe such as a cast iron pipe or a steel pipe in addition to the polyethylene pipe 3. Moreover, you may form the connection coupling member 2 in the edge part of a to-be-connected pipe | tube.

  The length adjustment allowance of the pipe to be connected by the pipe joint structure of the present invention will be described with reference to FIG.

  As shown in FIG. 4, the pipe A and the pipe B are laid horizontally vertically, and the pipe A and the pipe B are made of the polyethylene pipe 1 through the pipe joint structure of the present invention. Take as an example the case of being connected by.

  As shown in (a), the polyethylene pipe 1 was initially laid in a state where it was fitted in the inner part of the connecting joint member 2, but the space between the pipe A and the pipe B was widened by an earthquake or the like. In this case, since the polyethylene pipe 1 is connected via the pipe joint structure of the present invention, as shown in FIG. Therefore, the connection between the pipeline A and the pipeline B is reliably maintained.

  In this way, by connecting the pipes through the pipe joint structure of the present invention, when a pull-out force acts on the polyethylene pipe 1 during an earthquake or the like, the adjustment allowance for the length of the polyethylene pipe 1 is large. Without depending on the elongation due to the material of the polyethylene pipe 1, it is possible to cope with the withdrawal of the polyethylene pipe 1.

  Moreover, when it was set as temporary piping, the difference of the embedding depth of the pipe line A and the pipe line B was the extent which is shown to (a) at the first site, but in the state shown to (b) at the next site. there were. Even in such a case, the provisional allowance shown in FIG. 4 makes it possible to use this temporary pipe at both sites, and there is no need to newly prepare a temporary pipe for each site.

  Furthermore, although omitted in FIG. 4, if a connecting joint member having a pipe joint structure according to the present invention is used as a temporary pipe section connected to the pipe A which is a new pipe, Since adjustment in the horizontal direction is possible in addition to the adjustment, the connection work can be further improved.

  As described above, according to the pipe joint structure of the present invention, the polyethylene pipe 1 is reduced in diameter by pushing the sealing member 6, and thus the convex portion 5 b of the retaining member 5 on the inner peripheral surface of the polyethylene pipe 1. Compared to the conventional pipe joint structure in which the retaining ring 28 and the mechanical joint portion 24 are arranged side by side on the outer peripheral surface of the polyethylene pipe 1, the polyethylene pipe 1 extends from the pipe end along the pipe axis. Thus, the length (L1) of the space required for connection can be shortened (see FIG. 1). The length of the space in the conventional pipe joint structure is indicated by (L2) in FIG.

  Further, unlike the conventional pipe joint structure (see FIG. 5), it is not necessary to arrange the retaining ring 28 and the mechanical joint part 24 side by side on the outer peripheral surface of the polyethylene pipe 1, so the number of parts required for connection is reduced, And since it becomes possible to shorten the length (L1) of the space required for a connection, the range which can adjust the length of the polyethylene pipe | tube 1 freely can be ensured with a coupling. As a result, the connection work of the pipe joint can be improved.

1: Polyethylene pipe (connecting pipe)
2: Connection joint member (joint member)
2a: ridge 2b: bolt hole 3: polyethylene pipe (connected pipe)
4: Locking means 5: Locking member 5a: Flange 5b: Protruding part 6: Sealing member 7: Locking member 8: Pushing mechanism 9: Push ring 9a: Bolt hole 10: Bolt 11: Nut 21: Polyethylene tube 22 : Cast iron pipe 23: Flange fastening part 23a: Bolt hole 24: Mechanical joint 25: Reinforcement material 26: Lock ring 27: Color ring 28: Retaining ring 29: Push ring 29a: Bolt hole 30: Backup ring 31: Round rubber ring 32: Square rubber ring 33: Rubber ring 34: Washer 35: Bolt 36: Nut

Claims (13)

In the pipe joint structure provided with the retaining means for connecting the joint member to the end of the pipe to be connected,
The retaining means includes a retaining member inserted into a pipe end of the connection target pipe, and a clearance formed between an end inner peripheral surface of the joint member and an end outer peripheral surface of the connection target pipe. A sealing member inserted into the gap, a locking member that is inserted between the sealing member and the retaining member in the gap, and the sealing member is pushed in to connect the connection target pipe A pipe joint structure comprising a pressing mechanism that reduces the diameter and thus presses the inner peripheral surface of the connection target pipe against the outer peripheral surface of the retaining member.   The pipe joint structure according to claim 1, wherein a convex portion is formed on an outer peripheral surface of the retaining member to bite into an inner peripheral surface of the connection target pipe.   The pipe joint structure according to claim 2, wherein the convex portion has a tooth shape formed by two surfaces.   The convex portion has an insertion side surface of the retaining member and an anti-insertion side surface of the retaining member, and the angle of the insertion side surface with respect to the axis of the retaining member is the separation side of the anti-insertion side. The pipe joint structure according to claim 3, wherein the pipe joint structure is smaller than an angle with respect to an axis of the stopper member.   The pipe joint structure according to any one of claims 2 to 4, wherein the convex portion is formed in a spiral shape around an axis of the retaining member.   The pipe joint structure according to any one of claims 1 to 5, wherein an end face of the locking member on the sealing member side is formed in a convex shape.   The push-in mechanism includes a push ring that is in contact with the sealing member, and a bolt and a nut that fasten the push ring and the joint member. The pipe joint structure described in 1.   The pipe joint structure according to any one of claims 1 to 7, wherein the joint member connects an end of the connection target pipe and an end of the connection target pipe.   The pipe joint structure according to any one of claims 1 to 8, wherein the sealing member is made of rubber.   The pipe joint structure according to any one of claims 1 to 9, wherein the connection target pipe is made of resin.   The pipe joint structure according to claim 10, wherein the resin is polyethylene.   The pipe joint structure according to claim 8, wherein the connection target pipe is a metal pipe.   The pipe joint structure according to claim 8, wherein the connection target pipe is made of resin.

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