JP2013019463A - Earthquake-resistant pipe fitting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earthquake-resistant pipe fitting capable of absorbing the displacement of a connected pipe while water-tightness is maintained with no need of forming a spigot and a socket for exclusive use.SOLUTION: The earthquake-resistant pipe fitting includes: a cylindrical fitting body 4, into which each connecting side end of two pipes having a smooth outer surface is inserted; fixing brackets 5, 6, which are split by single or multiple cuts, have connection parts at the divided portions, and are mounted on the outer surface of the fitting body covering the connecting side ends; and fastening parts 7, 8, which fix the connecting side ends of the two pipes via the fitting body by the fixing brackets by connecting and fastening the connection parts of the fixing brackets. The fixing body comprises an elastic member. An expansion/contraction part 4a, which is bulged with approximately a U shaped cross section toward the inside of the fitting body and continuous in an annular shape in the circumferential direction, is provided at the center part in a cylinder axis direction. Each end at the opening side of the expansion/contraction part is covered by a connecting part 4d formed so as to be easily cut, elongated, and contracted.

Description

  The present invention relates to an earthquake resistant pipe joint for connecting a synthetic resin pipe for underground use.

  Conventionally, as shown in FIG. 4, there is known an earthquake-resistant joint in which an insertion port 50 is inserted into a receiving port 51 formed to have an inner diameter significantly larger than the outer diameter of the insertion port 50 and pipes are connected to each other. ing.

  In this type of seismic joint, when the insertion port 50 is inserted into the receiving port 51, the insertion projection 50 a formed on the outer periphery of the distal end of the insertion port 50 expands the lock ring 51 a provided on the receiving port 51. In this way, it enters the back of the receptacle and the connection is completed. Under such a connection structure, even if a force in the pull-out direction is applied to the joint portion due to an earthquake, several% of the pipe length is required until the insertion protrusion 50a moves backward and comes into contact with the lock ring 51a of the receiving port 51. Elongation is allowed (see, for example, Patent Document 1).

  In FIG. 4, reference numeral 51 b is a centering rubber that supports the lock ring 51 a, and 51 c is a sealing rubber that is housed on the inner wall of the opening side end of the receiving port 51.

JP 2003-185068 A

  However, in the conventional earthquake-resistant joint described above, when the insertion port 50 is connected to the receiving port 51, it is necessary to provide a clearance for allowing the insertion port protrusion 50a to pass between the outer surface of the insertion port and the inner surface of the receiving port. The clearance remains as a gap even after the insertion port 50 is connected to the receiving port 51.

  Therefore, when a load having a different size acts on the insertion port 50 and the receiving port 51 due to the vertical fluctuation of the ground with the insertion port 50 and the receiving port 51 connected to each other, the compressibility of the sealing rubber 51c is increased in the circumferential direction. As a result, there is a problem that watertightness cannot be maintained.

  Further, in the above earthquake-resistant joint, a dedicated insertion port must be formed at one end of the pipe to be connected, and a dedicated receiving port must be formed at the other end. Compared to the case of connecting cylindrical pipes, there is also a problem that the configuration becomes complicated and there is a restriction when designing the pipes of underground pipes.

  The present invention has been made in consideration of the problems in the conventional seismic joint as described above, and it is not necessary to form a dedicated insertion port and receiving port, and the displacement of the entire pipeline is maintained while maintaining watertightness. It is intended to provide a seismic pipe joint that can absorb the above.

The present invention is a tubular joint body into which the connection side ends of two pipes having smooth outer surfaces are inserted;
A fixing bracket mounted on the outer surface of the joint body, which is divided into one or a plurality of parts, has a connection part that is a pair in the divided part, and covers the connection side end part;
Fastening by connecting and fastening the connection portion of the fixing bracket, and fastening parts for fixing the connection side end of the two pipes with the fixing bracket via the joint body,
The joint main body is made of an elastic member, and is provided with an expansion / contraction part that bulges in a U-shaped cross section toward the inside of the joint main body in the cylindrical axial direction and continues in an annular shape in the circumferential direction. Each end portion is a seismic tube joint that is covered with a connecting portion that is easily cut, stretched, and contracted.

  In this invention, it is preferable that the thickness of the said connection part is the range of 0.5-5.0 mm. In addition, even if it is a case where it exceeds 5.0 mm, the effect that it will be easy to cut | disconnect, extend | stretch, and shrink | contract can be acquired if a cut | interruption which is easy to cut | disconnect, extend | stretch, and shrink | contract in the connection part. In addition to cutting, it is also conceivable to locally thin a part of the connecting portion. On the other hand, when the thickness of the connecting portion is less than 0.5 mm, it is difficult to perform molding, and there is a possibility that the pipe and the joint body may be broken when embedded.

  In the present invention, it is preferable to provide an adhesive layer or an integrally molded soft synthetic rubber on the inner surface of the joint body covering the connection side end. When the adhesive layer is provided, it is possible to absorb unevenness formed on the surface at the time of tube forming and to prevent generation of twisting and wrinkling when tightened with a fastening part.

  According to the present invention, there is no need to form a dedicated insertion port and receiving port at the connection side end of the tube, and the displacement of the connected tube can be absorbed while maintaining watertightness. Have

It is a front view which cut | disconnects and shows the structure of the earthquake-resistant pipe joint which concerns on this invention above a center axis | shaft. It is an expanded sectional view which shows the structure of the coupling main body of FIG. (a)-(c) is explanatory drawing which shows a mode that a seismic-resistant pipe joint absorbs the displacement of the pipe which has connected. It is a front view which cut | disconnects and shows the structure of the conventional seismic joint from the center axis | shaft.

  Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 shows a structure of a seismic pipe joint according to the present invention, in which the upper side of the center line CL of the composite pipe (pipe) shows a cross-sectional structure, and the lower side of the center line shows the appearance.

  The earthquake-resistant pipe joint 1 shown in the figure connects the connection side end portions of the composite pipes 2 and 3 inserted with a slight gap.

(1) Composite pipe Although the structure of the composite pipe 2 to be connected does not limit the present invention, for example, a pipe made of high-density polyethylene is preferably reinforced with a metal reinforcing material. Specifically, a reinforcing portion 2b having a convex cross section made of high density polyethylene is spirally wound around the outer peripheral surface of the inner tube 2a made of high density polyethylene, and the peak portion 2c of the reinforcing portion 2b is also made of high density polyethylene. The outer tube 2d is stretched over, and the inner surface of the inner tube 2a and the outer surface of the outer tube 2d are respectively smooth (flat).

  A metal reinforcing member 2e is embedded in the outer tube 2d integrally with the outer tube 2d so that it can counter external force while following the deformation of the composite tube 2.

  The composite tube 3 has the same configuration as the composite tube 2, 3a is an inner tube, 3b is a reinforcing portion, 3c is a mountain portion, 3d is an outer tube, and 3e is a metal reinforcing material.

(2) Structure of earthquake-resistant pipe joint (2-1) Structure of earthquake-resistant pipe joint In the earthquake-resistant pipe joint 1, the connection side end 2f of the composite pipe 2 and the connection side end 3f of the composite pipe 3 are inserted from both sides. A cylindrical joint body 4, and metal collars (fixing brackets) 5 and 6 mounted on the outer surface of the joint body 4 covering the connection side ends 2f and 3f after the composite pipe is inserted, It is mainly composed of fastening parts 7 and 8 for fastening the collars 5 and 6 in the circumferential direction, respectively.

(2-2) Joint Body FIG. 2 is an enlarged sectional view of the joint body 4.

  In the figure, the joint body 4 is made of an elastic member, for example, a synthetic rubber such as CR, EPDM, SBR, NBR, fluorine rubber, silicon rubber, etc., which is molded into a cylindrical shape, and an expansion / contraction portion 4a is provided at the central portion in the tube axis direction. It has been.

  The stretchable portion 4a bulges in a U-shaped cross section toward the inside of the joint body 4, and forms a ridge that continues in an annular shape in the circumferential direction.

  One of the features of the earthquake-resistant pipe joint according to the present invention is that each opening side end portion (annular groove portion) of the expansion and contraction portion 4a is covered with a connecting portion 4d formed so as to be easily cut, extended and contracted. is there.

  As shown in FIG. 1, since the expansion / contraction part 4a is covered by the connecting part 4d, when the earth and sand are backfilled around the joint body 4 to which the composite pipes 2 and 3 are connected, the backfilling earth and sand is expanded and contracted. The entry into the hollow portion S of the portion 4a is prevented. On the other hand, when the ground fluctuates due to an earthquake or the like, for example, when the composite pipes 2 and 3 are displaced away from each other, the connecting portion 4d is cut or stretched, and the expansion and contraction portion 4a freely deforms to absorb the displacement. It has become. The displacement pattern will be described later.

  Accordingly, the connecting portion 4d needs to be configured to be easily cut. In the present embodiment, the thickness t of the stretchable portion 4a is set to 5 to 15 mm, and the thickness t ′ of the connecting portion 4d that is easy to cut is set to a range of 0.5 to 5.0 mm.

  In addition, as a structure which is easy to cut | disconnect, not only reducing the thickness of the connection part 4d, but a notch like notch can also be provided in a part of the connection part 4d.

  In FIG. 2, a tube adherence portion 4e capable of covering the connection side end 2f (see FIG. 1) of the composite tube 2 is formed on the left side of the expansion / contraction part 4a, and the connection side end of the composite tube 3 is formed on the right side. A tube attaching portion 4f to be attached to 3f (see FIG. 1) is formed.

  Shallow recesses 4g and 4h are formed on the outer surfaces of the tube adherence portions 4e and 4f, and the collars 5 and 6 are positioned by attaching the collars 5 and 6 (see FIG. 1) to these recesses 4g and 4h. In addition, the joint body 4 can be securely fastened to the composite pipes 2 and 3 while preventing displacement between the pipe adherent portions 4e and 4f.

  On the other hand, raised portions 4i and 4j are formed on the inner surfaces of the tube adherent portions 4e and 4f in a slightly raised state, and shallow recessed portions 4k and 4l are formed on these raised portions 4i and 4j. In the recesses 4k and 4l, for example, sheet-like adhesive layers 4m and 4n made of unvulcanized butyl rubber, double-sided tape, integrally molded soft rubber, and the like are attached.

  Accordingly, when the composite pipes 2 and 3 are inserted from both sides of the joint body 4 and the joint body 4 is fastened to the composite pipes 2 and 3, first, the adhesive layers 4 m and 4 n are connected to the connection side ends of the composite pipes 2 and 3. It comes into contact with the portions 2f and 3f (see FIG. 1).

  Reference numerals 4o and 4p denote tapered portions for facilitating insertion of the composite tubes 2 and 3.

(2-3) Color In FIG. 1, the collar 5 is made of a pair of upper and lower strip-shaped steel plates made of stainless steel, for example, and is mounted on the outer surface of the joint body 4 covering the connection side end 2 f of the composite pipe 2. It has come to be.

  Further, the pair of upper and lower collars 5 are formed in such a length that an overlap margin can be secured at the connection portion when connected.

  A flange portion 5a is formed to protrude in the diametrical direction at each circumferential end of the collar 5 mounted from the upper side, and the flange 5a is similarly flanged at each circumferential end of the collar 5 mounted from the lower side. The portion 5a is formed so as to protrude, and when the pair of collars 5 are combined, the flange portion 5a is opposed (front side and back side in FIG. 1). These opposing flange portions 5a are provided with through holes for inserting bolts described later.

(2-4) Fastening component The neck portion of the hexagon head bolt 7a as the fastening component 7 is inserted into the through hole of the opposing flange portion 5a, and is fastened and fixed by the nut 7b.

  The collar 6 and the fastening part 8 thereof have the same configuration as the collar 5 and the fastening part 7 and will not be described.

(3) Operation of Seismic Pipe Joint FIGS. 3A to 3C are explanatory views showing the follow-up state of the joint body 4 when the composite pipes 2 and 3 connected to the earthquake resistant pipe joint 1 are displaced. .

  FIG. 4A shows the follow-up state of the joint body 4 when the composite pipes 2 and 3 are displaced in a direction closer to the construction.

  When the joint width 50 mm of the composite pipes 2 and 3 is reduced by 30 mm, the hollow elastic part 4a is in close contact, and the connecting part 4d is contracted or bent while the pressure in the hollow part is increased.

  The joint width of 50 mm is the distance between the connection side ends of the composite pipes 2 and 3 at the time of construction.

  FIG. 2B shows the follow-up state of the joint body 4 when the connection side ends of the composite pipes 2 and 3 are displaced in a direction away from the construction.

  When the joint width 50 mm is further extended by 30 mm, the connecting portion 4d breaks without being able to withstand the tensile load, and the U-shaped expansion / contraction portion 4a is displaced in an arc shape, but the tube adherent portion 4e follows the composite tube 2. However, the tube adherent portion 4 f follows the composite tube 3.

  FIG. 3C is an explanatory view showing the following state of the joint body 4 when the ground of one composite pipe 3 sinks.

  When the ground of the composite pipe 3 sinks by 50 mm, the connecting part 4d breaks without enduring the tensile load applied obliquely downward, and the U-shaped expansion / contraction part 4a is displaced in a hook shape, but the pipe attaching part 4e. Follows the composite tube 2, and the tube adherent portion 4 f follows the composite tube 3.

  In this way, the connecting part 4d prevents the earth and sand from entering the hollow elastic part 4a when connecting the composite pipes 2 and 3 by covering the hollow part S (FIG.) Of the elastic part 4a. However, when the ground fluctuates further due to an earthquake or the like, and the connecting side end of the composite pipes 2 and 3 is further displaced, it is cut by itself to absorb the displacement.

  Thereby, the seismic performance of the seismic pipe joint can be enhanced.

1 Earthquake-resistant pipe joints 2, 3 Composite pipe (pipe)
2a Inner pipe 2b Reinforcement part 2c Mountain part 2d Outer pipe 2e Metal reinforcement 2f Connection side end part 4 Joint body 4a Expansion / contraction part 4b Inner surface 4c Partition outer peripheral part 4d Connection part 4e, 4f Pipe adherence part 4g, 4h Concave part 4m, 4n Adhesive layer 5, 6 Color (fixing bracket)
7,8 Fastening parts

Claims (3)

A cylindrical joint body into which each connection side end of two pipes having smooth outer surfaces is inserted;
A fixing bracket mounted on the outer surface of the joint body, which is divided into one or a plurality of parts, has a connection part that is a pair in the divided part, and covers the connection side end part;
Fastening by connecting and fastening the connection portion of the fixing bracket, and fastening parts for fixing the connection side end of the two pipes with the fixing bracket via the joint body,
The joint main body is made of an elastic member, and is provided with an expansion / contraction part that bulges in a U-shaped cross section toward the inside of the joint main body in the cylindrical axial direction and continues in an annular shape in the circumferential direction. Each end portion is covered with a connecting portion formed so as to be easily cut, stretched, and contracted.   The earthquake-resistant pipe joint according to claim 1, wherein the thickness of the connecting portion is in the range of 0.5 to 5.0 mm.   The earthquake-resistant pipe joint according to claim 1 or 2, wherein an adhesive layer is provided on an inner surface of the joint body covering the connection side end.

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