JP4357831B2 - Synthetic resin pressure-resistant pipe body for flexible pipe joints - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a flexible synthetic resin for pipe joints suitable for use as a joint pipe body such as a drain outlet and a drain pipe or as a joint pipe body between pipes such as underground buried pipes and electric wire protection pipes. The present invention relates to a pressure-resistant tubular body.
[0002]
[Prior art]
Conventionally, for example, as a short tube for connecting hard synthetic resin drainage pipes installed outdoors, a flexible pipe made of a corrugated pipe or a bellows pipe made of soft synthetic resin such as soft vinyl chloride resin. However, according to such a flexible tube, since the inner and outer peripheral surfaces are formed in a spiral or bellows-like uneven surface, not only smooth drainage is performed, but also in the recess. There is a problem that impurities or the like adhere and accumulate and cannot be used for a long time.
[0003]
In addition, when the flexible pipe is used for connection between underground pipes made of hard synthetic resin such as drain pipes buried in the ground, it is deformed into a flat shape due to earth pressure because it is inferior in pressure resistance, and fluid flow In addition to hindering, there is a possibility that damage or the like may occur in a short period of time, so it cannot be used.
[0004]
For this reason, a rigid tube made of hard synthetic resin may be used as the tube for connecting the underground pipes. In the case of a rigid pipe, the open ends of the underground pipes facing each other are pipes. If it is oriented in a direction parallel to or intersecting the axis, the underground pipes cannot be connected to each other, and there is a great problem in workability.
[0005]
Therefore, as a pipe for a joint between hard synthetic resin underground pipes, even if the opening ends of the underground pipes facing each other are displaced, the underground pipes that are bent freely and are opposed to both ends of the opening It is desirable to have flexibility that can match the open end of the pipe and excellent pressure strength that can withstand earth pressure, but it has not yet been put to practical use as a pipe for such a joint. There is no current situation.
[0006]
On the other hand, a synthetic resin pipe having flexibility and pressure strength has been developed, although it is not a joint pipe body between underground pipes. As such a pressure-resistant synthetic resin tube having flexibility, a helical reinforcement body made of a hard synthetic resin material is spirally wound around the outer peripheral surface of a soft synthetic resin hose at a constant pitch, and a flexible synthetic resin hose can be used. It is comprised so that the pressure-resistant intensity | strength by this spiral reinforcement body may be exhibited with flexibility (for example, refer patent document 1).
[0007]
[Patent Document 1]
JP-A-10-110869 (page 2, FIG. 1).
[0008]
[Problems to be solved by the invention]
However, according to the pressure-resistant synthetic resin tube, the spiral reinforcing body spirally wound around the outer peripheral surface of the soft synthetic resin hose is one end of the narrow bottom portion fused to the outer peripheral surface of the soft synthetic resin hose. Since it has a structure in which a gap is provided between the hook-shaped projecting portions of the adjacent spiral reinforcing bodies, the projecting portion extends from the base portion in the opposite direction to the bottom side portion. There is a risk that soil and sand may enter the space between the outer peripheral surface of the soft synthetic resin hose and the inner peripheral surface of the bowl-shaped protruding portion through the gap and damage the soft synthetic resin hose. In addition, there is a possibility that adhesion and deposition may impair the flexibility, and in addition, when another object is caught on the tip of the hook-shaped protruding portion during handling or construction, the spiral reinforcing body having the hook-shaped protruding portion If there is a risk of damage, handling should be careful There is a problem.
[0009]
Further, when this pressure-resistant synthetic resin tube is bent in an arc shape, on the side of the peripheral wall portion curved in a convex arc shape, the hook-like projecting portions in the adjacent spiral reinforcing bodies are further separated by a tensile force in the length direction. When the outer peripheral surface of the soft synthetic resin hose portion between the bottom portions of the adjacent spiral reinforcement body from the separated portion is exposed to the outside, and the exposed portion is buried by another object or in the ground, earth and sand, etc. May cause direct damage.
[0010]
Further, even if this pressure-resistant synthetic resin pipe is cut into a short shape and used as a pressure-resistant pipe body for a pipe joint, the spiral reinforcing body is wound around the outer peripheral surface. Even if the outer peripheral surface of the reinforcing body is fitted into the end of the underground pipe in a watertight manner, the water from the underground pipe leaks to the outside through the spiral groove formed between the spiral reinforcing bodies. Become. Therefore, it is necessary to bury the synthetic resin resin in the spiral groove portion of the spiral reinforcing body portion to be inserted into the end portion of the underground tube, and to smoothly finish the outer peripheral surface. There was a problem that it was difficult to finish accurately.
[0011]
The present invention has been made in view of the above problems, and its object is to have excellent pressure strength and wear resistance, exhibit good flexibility, and It is an object of the present invention to provide a synthetic resin pressure-resistant tubular body for a pipe joint that is difficult to cause damage and that is flexible and can be connected to a hard synthetic resin pipe such as a buried underground pipe with high accuracy in a watertight manner. .
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the flexible synthetic resin pressure-resistant tubular body for a pipe joint according to the present invention has a constant thickness on the outer peripheral surfaces of both ends of the soft synthetic resin inner pipe as described in claim 1. The short tube portion made of hard synthetic resin is attached, and the inner and outer peripheral surfaces are formed on the connecting tube end portions having smoothness and rigidity, and the soft synthetic resin made between these connecting tube end portions is made. On the outer circumference of the inner pipe A hard synthetic resin reinforcing wire is spirally wound at a constant pitch, and on this hard synthetic resin reinforcing wire Rigid synthetic resin strip with constant width While gluing and integrating the inner surface of one end of the spiral at the same pitch as above, Wound first Made of hard synthetic resin Strip material part One end of Next rolled up Made of hard synthetic resin The strips are overlapped so as to be slidable with each other while being shifted by a certain width in the tube axis direction. By A hard synthetic resin outer shell is formed, and adjacent to the outer shell. Reinforced wire made of hard synthetic resin A flexible part is formed by a part of the inner tube made of soft synthetic resin exposed between the flexible part and the flexible part. Made of the above hard synthetic resin The entire surface is covered with the inner surface of the intermediate portion in the width direction of the belt-shaped material portion.
[0013]
In the pressure-resistant tubular body made of synthetic resin for a pipe joint having such a configuration, the invention according to claim 2 Of the pressure-resisting tube made of synthetic resin It is characterized in that at least one of the connecting pipe end portions formed at the both end portions is formed at the diameter expanding tube end portion.
[0014]
[Action and effect]
Outer peripheral surface excluding both ends of the inner tube made of soft synthetic resin A hard synthetic resin reinforcing wire is spirally wound at a constant pitch on the hard synthetic resin reinforcing wire. Rigid synthetic resin strip with constant width Inside of one end of Are fixed together by adhesion by fusion or the like, and the other end side of the next wound belt-like material portion is slidably superimposed on the fixed portion of the previously wound belt-like material portion Same as above Since the flexible portion is formed by a part of the inner tube made of the soft synthetic resin that is spirally wound with a pitch and is exposed between the fixed portions of the adjacent band-shaped material portions, both ends are formed by the flexible portion. When connecting the pipes made of hard synthetic resin with uniform and good flexibility on the whole, the open ends of these pipes are arranged on the same pipe axis. Even if not, both ends of the joint pipe can be easily and accurately matched to the open ends of the opposing pipes.
[0015]
Further, the cross section of the spiral flexible portion is not deformed into a buckling shape by the fixing portion of the hard synthetic resin strip wound spirally around the outer peripheral surface of the soft synthetic resin inner tube. It can be uniformly bent while being held, and drainage and the like can be smoothly distributed.
[0016]
In addition, the exposed portion of the soft synthetic resin inner tube forming the flexible portion of the tube is covered with the inner surface of the intermediate portion in the width direction of the hard synthetic resin strip-shaped material portion, and the inner portion made of the soft synthetic resin is covered. Adjacent hard synthetic resin strips spirally wound on the pipe are slidably overlapped with each other, so the soft synthetic resin inner tube is wound in this spiral The outer shell made of material covers and protects the entire surface without any gaps. Therefore, even if it is used as a pipe for a joint between underground pipes, it is uniform over the entire length by this hard synthetic resin outer shell. Exhibits wear resistance and pressure resistance, and the adjacent hard synthetic resin strips are overlapped in a cross-sectional shape without any gaps, so that earth and sand penetrate into the outer peripheral surface of the soft synthetic resin inner tube. There is no risk of damaging the inner tube made of soft synthetic resin. It is possible to provide a pressure-resistant synthetic resin pipe to be subjected to long-term use quality synthetic resin inner tube and fully protected.
[0017]
Further, only the inner peripheral surface of one end of the belt-shaped material forming the outer shell made of hard synthetic resin is spirally formed at a constant pitch on the outer peripheral surface of the inner tube made of soft synthetic resin. For wrapping hard synthetic resin reinforcing wire Adhering and fixing, and the overlapping part of the adjacent rigid synthetic resin strips are overlapped so as to be slidable in a cross-sectional scale without bonding together, so this pipe joint tube was bent Sometimes, the band-shaped material part made of hard synthetic resin that is superposed on the scale section is One end It can be bent smoothly while sliding in the tube axis direction with the fixed part as a fulcrum, and even when bent largely, the adjacent hard synthetic resin strips keep overlapping each other and are softly synthesized The resin inner pipe is protected, and a predetermined pressure strength can be maintained. Moreover, since the inner peripheral surface of the soft synthetic resin inner pipe is formed in a substantially flat surface over the entire length, the drainage and the like are smoothly distributed.
[0018]
Furthermore, the both ends of the synthetic resin pressure-resistant pipe body for pipe joints are attached to the outer peripheral surface of both ends of the soft synthetic resin inner tube with a hard synthetic resin short tube portion having a certain thickness, and the inner and outer peripheral surfaces are Since it is formed at the end of the connecting pipe that is smooth and rigid, when connecting the hard synthetic resin pipes such as underground pipes with this pipe joint pipe, the open ends of these pipes In addition, the pipe end portion of the pipe joint pipe body can be fitted inside or outside in a watertight manner with high accuracy and easily through an adhesive or a sealing material. In addition, when the pipe such as the underground pipe and the pipe end of the pipe joint pipe body have substantially the same outer diameter, the opening end face of the pipe end is provided on the opening end face of the pipe such as the underground pipe. A short tube member is put between the outer peripheral surfaces of the opening end portions in a butted manner, and can be connected in a watertight manner with high accuracy and easily via an adhesive or a sealing material.
[0019]
The hard synthetic resin outer shell covering the entire outer peripheral surface of the soft synthetic resin inner pipe is: As above, A hard synthetic resin reinforcing wire is spirally wound around the outer peripheral surface of the soft synthetic resin inner pipe between the connecting pipe ends at a constant pitch, and the hard synthetic resin reinforcing wire is made on the hard synthetic resin reinforcing wire. The inner surface of one end of the belt-like material is fused or bonded with an adhesive or the like, and then wound on one end of the hard synthetic resin-made belt-like material portion that has been spirally wound at the same pitch as described above and then wound. A hard synthetic resin outer shell is formed by slidably overlapping the other end of the rotated hard synthetic resin strip. Because of the inner tube made of soft synthetic resin Pipe body for pipe joints that is hard to be crushed and deformed by a rigid synthetic resin reinforcing wire spirally wound on the outer peripheral surface, and further increases pressure resistance and makes it even more uniform and exhibits good flexibility Can be obtained.
[0020]
In addition, if the thickness of the hard synthetic resin reinforcing wire is formed to be approximately the same as the thickness of the hard synthetic resin short tube portion forming the connecting pipe end, the hard synthetic resin reinforcing wire is softly synthesized. Rigid synthetic resin of the desired length by adhering the reinforcing wire part wound first on the inner pipe made of resin and the reinforcing wire part wound next to each other by fusion or the like while keeping the opposite end surfaces thereof in close contact with each other An adjacent reinforcing wire portion can be formed by spirally winding the reinforcing wire portion from the hard synthetic resin tubular portion onto the soft synthetic resin inner tube at a predetermined pitch. A tubular body in which a part of the soft synthetic resin inner tube that becomes a flexible portion is exposed can be continuously formed, and the tubular body for a pipe joint can be efficiently manufactured.
[0021]
Claim 2 According to the invention according to the present invention, since at least one of the connection pipe end portions formed at both ends of the pipe joint tube body is formed at the diameter expansion tube end portion, the diameter expansion tube is provided only at one end portion. By using the pipe joint tube forming the end, it is possible to securely connect the hard synthetic resin male pipe and female pipe in underground pipes, etc. By using the tubular body for a pipe joint that forms the pipe, it is possible to reliably connect the hard synthetic resin male pipes in the underground pipe or the like.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Next, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a vertical side view of a flexible synthetic resin pressure-resistant pipe body A (hereinafter referred to as a pipe joint pipe body A) having flexibility, and FIG. 2 is a side view of the pipe joint pipe body. A is a hard synthetic resin short tube portion made of a hard vinyl chloride resin having a constant thickness thicker than the inner tube 1 on both outer peripheral surfaces of the soft synthetic resin inner tube 1 having a predetermined length made of a soft vinyl chloride resin. 3 'is applied, and the inner and outer peripheral surfaces are smooth and rigid (rigidity) formed on connecting pipe end portions 2 and 2, and the softness between these connecting tube end portions 2 and 2 A rigid synthetic resin strip 3A made of hard vinyl chloride resin having a certain width is fixed to the outer peripheral surface of the synthetic resin inner pipe 1 by fusing the inner peripheral surface side of one end in the width direction, and the tip is fixed. Next, it is made of a hard synthetic resin wound in one turn on the fixed part 4 of the strip-shaped material part 3a wound in one turn. The width direction of the other end portion the inner surface of the Jozai portion 3a with a constant pitch while slidably superimposed sectional scaly form a hard synthetic resin shell 3 by spirally wound.
[0023]
It should be noted that the synthetic resins are bonded and integrated, for example, the rigid synthetic resin short tube portion 3 'is bonded onto the soft synthetic resin inner tube 1 or is made of a hard synthetic resin. Strip material Adhesion on the inner peripheral surface side of 3A, or adhesion of one end of the hard synthetic resin strip 3A wound next onto the fixed portion 4 (thick rib portion 3B described later) of the hard synthetic resin strip 3A Etc. are performed by fusion of synthetic resin, but may be performed using an adhesive. However, in the following description, it will be described as fusion.
[0024]
In the hard synthetic resin strip 3A forming the hard synthetic resin outer shell 3, the inner surface of one end in the width direction fixed to the outer peripheral surface of the soft synthetic resin inner tube 1 is a thick rib portion. The other end of the thin synthetic resin strip 3A that is formed on 3B and then wound on the thick rib 3B is overlapped without being fused, and therefore adjacent to the tube axis direction. A portion of the soft synthetic resin inner tube 1 is exposed between the thick rib portions 3B and 3B to be exposed 1a, and this exposed portion 1a is formed in a continuous spiral shape in the tube axis direction so that the flexible portion of the tube A 1A is formed. Further, the exposed portion 1a of the soft synthetic resin inner tube 1 forming the flexible portion 1A is formed of the hard synthetic resin strip-shaped material portion 3a existing between the outer peripheral surfaces of the adjacent thick rib portions 3B and 3B. It is covered with the inner surface of the intermediate portion in the width direction (tube axis direction).
[0025]
The soft synthetic resin inner tube 1 and the hard synthetic resin outer shell 3 are made of soft and hard vinyl chloride resin, respectively, but are made of other homogeneous materials with good adhesion and different hardness. You may form from a resin material, for example, a hard polyethylene resin, a soft polyethylene resin, etc.
[0026]
The hard synthetic resin strip 3A spirally wound on the soft synthetic resin inner tube 1 is formed in a shape in which the thick rib portion 3B having a rectangular cross section is integrally provided on the inner surface of one end thereof. However, as this thick rib portion 3B, as shown in FIG. 4, a hard synthetic resin reinforcing wire 3B separate from the hard synthetic resin strip 3A (in this case, it is formed thinly over the entire width). The hard synthetic resin reinforcing wire 3B 'is formed at a constant pitch on the outer peripheral surface of the soft synthetic resin inner pipe 1 between the connecting pipe end portions 2 and 2 in the pipe joint pipe body A. Thus, the fixed portion 4 is wound and fused spirally to form the fixed portion 4, and the inner surface of one end of the hard synthetic resin strip 3A formed thinly over the entire width on the hard synthetic resin reinforcing wire 3B '. Are fused and integrated, and spirally wound at the same pitch as the hard synthetic resin reinforcing wire 3B ′, Cover the exposed portion 1a of the soft synthetic resin inner pipe 1 exposed between the hard synthetic resin reinforcing wires 3B 'and 3B' on the inner surface of the intermediate portion in the width direction of the synthetic resin strip 3A and hard composite On the other end side of the hard synthetic resin strip 3a wound next on one end of the previously wound hard synthetic resin strip 3a that is fixed integrally with the resin reinforcing wire 3B '. The hard synthetic resin outer shell 3 is formed by slidably superimposing inner surfaces.
[0027]
The width between both ends in the tube axis direction of the hard synthetic resin strip 3A, that is, the width W between both long side edges is the thick rib portion 3B of the hard synthetic resin strip 3A or the hard synthetic resin It is formed with a width larger than the spiral winding pitch P of the reinforcing wire 3B ', and therefore the hard synthetic resin strip 3A is soft with the same pitch as the thick rib portion 3B or the hard synthetic resin reinforcing wire 3B'. In the form in which the hard synthetic resin outer shell 3 is formed by spirally winding on the synthetic resin inner pipe 1, the hard synthetic resin is then wound on the hard synthetic resin strip 3 a previously wound. As described above, the strip-shaped material portion 3a is superposed in a cross-sectional scale shape in a state where the band-shaped material portion 3a is shifted by the winding pitch P in the tube axis direction.
[0028]
For example, in the pipe body A for a pipe joint shown in FIG. 1, the width W of the hard synthetic resin strip 3A is formed to be the winding pitch P + the width of the thick rib portion 3B, and is therefore wound first. The distal end portion (the other end portion) of the hard synthetic resin strip member 3a wound next on the thick rib portion 3B of the hard synthetic resin strip member 3a entirely overlaps. On the other hand, in the pipe joint tube A shown in FIG. 4, the width W of the hard synthetic resin strip 3A is formed to be approximately twice the winding pitch P, and therefore, the hard synthetic resin wound earlier is made. 1/2 width on the other end side (tip end side) of the rigid synthetic resin band member 3a wound next on the 1/2 width portion on the one end side (base end side) of the band-like material portion 3a It is in a state where the parts overlap. Further, the overlapping portions are not fused and are in close contact with each other so that the opposing surfaces can slide.
[0029]
As shown in FIG. 6, for example, the pipe body A for a pipe joint configured as described above is a pipe joint that connects the hard synthetic resin drain pipes C and C such as hard vinyl chloride resin pipes embedded in the ground. Used as. At this time, even if the opposite open ends of the drain pipes C, C to be connected by the pipe joint tube A are not arranged on the same axis and their directions are deviated from each other, The tube A is connected at both ends by the flexible portion 1A exposed between the thick rib portions 3B and 3B of the hard synthetic resin strip material portion 3a or between the hard synthetic resin reinforcing wires 3B 'and 3B'. Since it can be bent uniformly over the entire length excluding the pipe end portions 2 and 2, the connecting pipe end portions 2 and 2 at the both end portions can be easily formed at the opening end portions of the drain pipes C and C facing each other. And it can be made to match exactly and connect.
[0030]
In this connection work, both the outer diameters of the connecting pipe ends 2 and 2 of the pipe joint pipe A are formed to be substantially equal to the outer diameter of the pipe A, while the drain pipes C and C are open end parts. The outer diameter of the connecting pipe ends 2 and 2 of the pipe joint pipe body A is equal to the outer diameter of the connecting pipe ends 2 and 2. A short tube member is placed between the outer peripheral surfaces of these opening end portions so as to face the opening end surfaces facing each other, and watertight connection is made via an adhesive or a sealing material.
[0031]
Further, when the opening ends facing the drain pipes C and C are formed at the enlarged diameter ends C1 and C1, as shown in FIG. 6, the adhesive or the If the connecting pipe ends 2 and 2 of the pipe joint pipe body A are inserted in a watertight manner through a sealing material or the like, the drain pipes C and C are connected by the pipe joint pipe body A. Can do. In any case, since the outer peripheral surfaces of the connecting pipe end portions 2 and 2 of the pipe joint pipe body A are formed by the smooth rigid synthetic resin short tube portion 3 ', the connecting pipe end portion 2 and 2 can be reliably and easily water-tightly connected between the opening ends of the drainage pipes C and C through a sealing material, and the soft synthetic resin inner pipe 1 in the pipe joint A is used. Since the formed inner peripheral surface is also smooth over the entire length, the drainage can flow smoothly.
[0032]
As shown in FIG. 7, the connecting pipe end portions 2, 2 of the pipe joint tube A have one connecting pipe end portion 2 ′ having a larger diameter than the other connecting pipe end portion 2. The connecting pipe ends 2 ′ and 2 ′ may be formed at the end of the expanded pipe as shown in FIG. According to the pipe joint tube A configured in this way, in the former case, open end portions of a large and small diameter connecting pipe end portion 2 ', 2 and a drain pipe which is a male pipe and a drain pipe which is a female pipe. Can be connected to each other via an adhesive or a sealing material. In the latter case, the opposite ends of the drain pipes are connected to the diameter-expanded pipe ends 2 ′ and 2 ′ via an adhesive or a sealing material, respectively. Can be connected by fitting them inside.
[0033]
Further, the pipe joint tube A includes a rigid synthetic resin inner pipe 1 between the rigid connecting pipe end portions 2 and 2 formed at both ends, and a hard synthetic resin outer shell 3 which is a gap over the entire length. Therefore, it is possible to reliably prevent the earth and sand from entering the soft synthetic resin inner pipe 1 side, and therefore, it is possible to prevent the soft synthetic resin inner pipe 1 from being damaged and this hard The synthetic resin outer shell 3 exhibits good wear resistance, and the hard synthetic resin outer shell 3 is a thick synthetic resin strip 3A thick rib portion 3B or a hard synthetic resin reinforcing wire. Along with 3B ', it exerts a large pressure resistance and can be used for a long time without causing crushing or deformation.
[0034]
Further, as shown in FIGS. 3 and 5, when this pipe joint tube A is bent (curved) in an arc shape, the soft synthetic resin inner pipe 1 is easily bent and the inner pipe 1 and the hard synthetic resin are bent. The outer shell 3 is also bent together. At this time, the bending form of the hard synthetic resin outer shell 3 is such that, in the outer peripheral wall portion A1 bent into a convex arc shape, the adjacent hard synthetic resin belt-shaped material portion forming the hard synthetic resin outer shell 3 is formed. 3a, 3a slides in directions opposite to each other, while the inner peripheral wall portion A2 bent in a concave arc shape generates a compressive force in the tube axis direction, and the hard synthetic resin adjacent to the tube axis direction by the compressive force Between the thick rib portions 3B and 3B of the strip-shaped material portions 3a and 3a, or between the hard synthetic resin reinforcing wire rods 3B 'and 3B', contracts in the arc length direction, and the contraction of the rigid synthetic resin strip-shaped material portion 3a , 3a will be in a state where they are further firmly pressed together.
[0035]
Next, the manufacturing method of the pipe joint tube A configured as described above will be briefly described with reference to FIG. 9. A strip material made of a soft synthetic resin made of a soft vinyl chloride resin in a semi-molten state having a certain width and thickness will be described. As is well known, while extruding 11 from the first molding nozzle 21, the other side portion of the following strip-like material portion 11 a is superimposed on one side portion of the preceding strip-like material portion 11 a on the base end portion of the molding rotary shaft 20. The inner tube 1 made of soft synthetic resin is formed by spirally winding at a constant pitch while being fused together, and the second molding nozzle 22 is formed on the inner tube 1 made of soft synthetic resin. A rigid synthetic resin reinforcing wire 3B ′ wound in a single roll while extruding a reinforcing wire 3B ′ made of hard polyvinyl chloride resin in a semi-molten state with a rectangular cross section (may be elliptical) Next, a hard synthetic resin reinforcing wire 3B 'wound in a single roll Are joined and fused in the direction of the tube axis while being spirally wound at a constant pitch, thereby forming a hard synthetic resin cylindrical portion 2A having a predetermined length.
[0036]
When the hard synthetic resin cylinder portion 2A is formed to a predetermined length, the amount of extrusion of the hard synthetic resin reinforcing wire 3B ′ extruded from the second molding nozzle 22 is reduced, or the second molding nozzle 22 The extruded hard synthetic resin reinforcing wire 3B 'is narrowed by passing through an appropriate guide member, and the soft synthetic resin inner tube 1 having the same pitch as above is used to narrow the narrow hard synthetic resin reinforcing wire 3B'. The inner surface of this hard synthetic resin reinforcing wire 3B 'is spirally wound up and fused and fixed 4 to the inner tube 1 made of soft synthetic resin. A flexible portion 1A is formed by exposing a part of the soft synthetic resin inner tube 1.
[0037]
Further, a semi-molten hard synthetic resin strip 3A made of the same material as the hard synthetic resin reinforcing wire 3B 'is extruded from the third molding nozzle 23, and the inner surface of one end portion on one long side is hard synthesized. The rigid synthetic resin reinforcing wire 3B ′ is superposed without being fused on the rigid synthetic resin strip 3a which is integrally fused on the resin reinforcing wire 3B ′ and the other end is wound first. The hard synthetic resin outer shell 3 is formed by spirally winding with the same pitch.
[0038]
At this time, before the semi-molten hard synthetic resin strip 3A is spirally wound, the semi-molten hard synthetic resin strip 3A extruded from the third molding nozzle 23 is cooled by a cooling device 24 by blowing cold air or the like. When the belt-like material portions 3a and 3a are superposed on each other on the inner tube 1 made of soft synthetic resin, they are spirally wound without being fused to each other, and only the inner peripheral surface of one end thereof is heated by the heating device 25. It is heated and melted and fused integrally to the hard synthetic resin reinforcing wire 3B ′.
[0039]
In this way, after forming a flexible pressure-resistant synthetic resin pipe portion having a predetermined length and having a flexible synthetic resin outer shell 3 on the outer peripheral surface of the soft synthetic resin inner pipe 1 on the molding rotary shaft 20, again. The hard synthetic resin cylindrical portion 2A having the predetermined length is continuously formed, and the rigid synthetic resin cylindrical portion 2A and the flexible pressure resistant synthetic resin pipe portion having the predetermined length are alternately and continuously formed. To form.
[0040]
Then, the rigid synthetic resin cylinder portion 2A fed out from the molding rotary shaft 20 is sequentially cut at the central portion in the length direction so as to have connecting tube end portions 2 and 2 at both ends, and these connecting tube ends. A pipe joint tubular body A is obtained in which a pipe part between the parts 2 and 2 is formed on a flexible rigid pipe part covered with a hard synthetic resin outer shell 3.
[0041]
Since the hard synthetic resin strip 3A used for forming the hard synthetic resin outer shell 3 is wound around the outer peripheral surfaces of the connecting pipe ends 2, 2 of the pipe joint tube A, The hard synthetic resin strip 3A is ground and the surfaces of the connecting pipe ends 2 and 2 are polished to a smooth surface. Grinding and polishing operations on the surfaces of the connecting pipe end portions 2 and 2 are performed on the hard synthetic resin cylindrical portion 2A formed on the molding rotary shaft 20 to be the connecting pipe end portions 2 and 2. Good.
[0042]
In addition, in the manufacturing method of the pipe joint pipe A described above, the hard synthetic resin reinforcing wire 3B ′ is used for forming the hard synthetic resin outer shell 3, but such a hard synthetic resin reinforcing wire is used. Without using 3B ', the thick rib portion 3B is fed from the molding nozzle while integrally forming the thick rib portion 3B on the inner peripheral surface of one end of the hard synthetic resin strip 3A, and the thick rib portion of this hard synthetic resin strip 3A The hard synthetic resin strip 3A may be spirally wound at a constant pitch while 3B is directly fused to the outer peripheral surface of the soft synthetic resin inner tube 1. Further, without providing the thick rib portion 3B, the inner peripheral surface of one end portion of the thin hard synthetic resin strip-like material 3A is fused directly to the outer peripheral surface of the soft synthetic resin inner tube 1 over the entire width. The hard synthetic resin strip 3A may be spirally wound at a constant pitch. Moreover, you may form the cross-sectional shape of a hard synthetic resin strip | belt-shaped material in shapes other than the above.
[0043]
In addition, in the method of manufacturing the pipe joint tube A, the hard synthetic resin cylindrical portion 2A is molded on the molding rotating shaft 20 in order to form the expanded pipe end 2 'as the connecting pipe end 2. At the time of molding, a molded cylindrical member composed of a combination of a half-cylindrical member having the same length as that of the hard synthetic resin cylindrical portion 2A is removably mounted on the molding rotary shaft 20 of the molded portion. A soft synthetic resin strip 11 made of a soft vinyl chloride resin in a semi-molten state having a certain width and thickness, which forms the soft synthetic resin inner tube 1 on the member, is spirally wound in the same manner as described above, and this soft synthetic resin The rigid synthetic resin reinforcing wire 3B 'is sequentially wound on the strip 11 and spirally wound with the opposite side surfaces joined and fused to form a rigid synthetic resin cylinder, and the rigid synthetic resin cylinder is divided into two parts. After that, by forming the molded cylindrical member from the inside It can be.
[0044]
In the above-described embodiment of the pipe joint tube A, the flexible hard synthetic resin outer shell 3 formed between the connecting pipe ends 2 and 2 at both ends extends over the entire length. However, as shown in FIG. 10, a pipe having a rigid pipe portion 5 having the same structure as that of the connecting pipe end portion 2 in the middle portion, that is, two pipe fitting pipes A, The present invention can be satisfied even with the pipe joint tube A ′ having a structure formed integrally in series. According to such a pipe joint tube A ′, two flexible synthetic resin outer shells 3 ′ and 3 ′ are formed between the connecting pipe ends 2 and 2 at both ends. Therefore, it is easy to connect two hard synthetic resin buried pipes that are piped with their pipe axes parallel to each other, and even when the pipe axis at the opposite open end is slightly displaced from side to side. The range of use is widened.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view with a part omitted.
FIG. 2 is a simplified side view of the entire tubular body.
FIG. 3 is a longitudinal side view of the bent state.
FIG. 4 is a vertical sectional side view showing another embodiment with a part thereof omitted.
FIG. 5 is a longitudinal side view of the bent state.
FIG. 6 is a simplified side view showing a use state.
FIG. 7 is a simplified side view of a tubular body having an enlarged diameter pipe end portion at one end portion.
FIG. 8 is a simplified side view of a tubular body in which a diameter-expanded pipe end is formed at both ends.
FIG. 9 is a simplified side view of the main part for explaining the manufacturing method.
FIG. 10 is a side view showing still another embodiment of the present invention.
[Explanation of symbols]
A Pipe body for fittings
1 Inner tube made of soft synthetic resin
1A flexible part
1a Exposed area
2 Pipe end for connection
3 Outer shell made of hard synthetic resin
3 'short tube made of hard synthetic resin
3A Band made of hard synthetic resin
3B 'Reinforced wire made of hard synthetic resin
3a Band made of hard synthetic resin
4 fixed parts

Claims (2)

A hard synthetic resin short tube portion having a certain thickness is attached to the outer peripheral surfaces of both ends of the soft synthetic resin inner tube, and the inner and outer peripheral surfaces are formed on the connecting tube end portion which is smooth and rigid, A hard synthetic resin reinforcing wire is spirally wound around the outer peripheral surface of the soft synthetic resin inner tube between the connecting pipe end portions at a constant pitch. On the hard synthetic resin reinforcing wire The inner surface of one end of a hard synthetic resin strip having a certain width is spirally wound at the same pitch as above while adhering and integrating the inner surface of the hard synthetic resin strip, and then on one end of the previously wound hard synthetic resin strip. wrapping hard synthetic resin strip material portion the tube axis direction at a constant width, Yes to form a hard synthetic resin shell by Rukoto allowed slidably overlapped with each other in a staggered state, further, the adjacent hard synthetic some of the soft synthetic resin inner tube which is exposed between the resin reinforcing wire member Accordingly tube having together forming the flexible portion, the flexible, characterized in that it is entirely covered with the flexible portion by the width direction of the intermediate inner surface of the hard synthetic resin strip material portion Synthetic resin pressure tube for fittings. 2. The flexible synthetic resin pressure-resistant pipe for a pipe joint according to claim 1 , wherein at least one of the connecting pipe ends is formed at an enlarged diameter pipe end.

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