AU2018243151B2

AU2018243151B2 - Pipe joint, rectangular electric wire pipe, and pipe joint connection structure

Info

Publication number: AU2018243151B2
Application number: AU2018243151A
Authority: AU
Inventors: Yasuki Kimura; Satoshi Kozawa; Yuzo Nakajima
Original assignee: Furukawa Electric Co Ltd
Current assignee: Furukawa Electric Co Ltd
Priority date: 2017-03-31
Filing date: 2018-01-15
Publication date: 2020-10-08
Anticipated expiration: 2038-01-15
Also published as: AU2018243151A1; WO2018179680A1; MY194814A

Abstract

A pipe joint 1 for a rectangular electric wire pipe mainly comprises a joint body 3 and a Π-shaped fixing member 5. The Π-shaped fixing member 5 comprises a top surface portion 7 and a pair of leg portions 9. A small diameter portion fixing portion 2 is formed on one side of the joint body 3. The small diameter portion fixing portion 2 is a part for fixing a pipe body small diameter portion of a rectangular electric wire pipe described below. A male fitting portion 4 is formed on the other side of the joint body 3. The male fitting portion 4 functions as a fixing portion for a female fitting portion of the rectangular electric wire pipe described below. A connection wall 34 perpendicular to the pipe axis direction of the joint body 3 is formed between the small diameter portion fixing portion 2 and male fitting portion 4 of the joint body 3. That is, the small diameter portion fixing portion 2 and the male fitting portion 4 are connected to each other at the connection wall 34.

Description

PIPE JOINT, RECTANGULAR ELECTRIC WIRE PIPE, AND PIPE JOINT CONNECTION STRUCTURE TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a pipe joint for rectangular electric wire pipes for connecting rectangular electric wire pipes, through which electric wires are inserted, with the others and a connection structure for a rectangular electric wire pipe and a pipe joint.

BACKGROUND OF THE INVENTION

[0002] A round electric wire pipe with a circular cross section and a rectangular electric wire pipe with a rectangular cross section have been proposed as underground-laid electric wire protective pipes, for example. Although round electric wire pipes have been conventionally used in many cases, for use as electric wire pipes in construction sites such as a tunnel in which laying space for the electric wire pipes is small, rectangular electric wire pipes with rectangular cross sections have been in use. To give flexibility, a rectangular electric wire pipe has flexibility, having alternatively formed rectangular cross sections and circular cross sections.

[0003] Also, when digging up a road and laying electric wire pipes underground, using rectangular electric wire pipes makes it possible to lay a plurality of adjacent electric wire pipes contacting with each other. In this way, amount of soils to be dug up is less than that in a case in which electric wire pipes with circular cross sections are laid underground, and this makes the construction easier.

[0004] For connecting such rectangular electric wire pipes with the others, pipe joints for rectangular electric wire pipes have been used. For example, a pipe joint including a joint body made of synthetic resin and a flange rim projecting in an outer periphery direction from both ends of a semi-arctic shape has been proposed (Patent Document 1).

[0005] The joint body of the pipe joint in Patent Document 1 includes a recessed groove for accommodating water-sealing packing at parts other than and between rim portions on both sides in a width direction thereof. By screwing bolts into bolt holes for screwing on both end portions in a circumference direction of the joint body, the joint body with water-sealing packing can be fixed to a pipe body made of synthetic resin having wavy shape. The pipe joint according to Patent Document 1 can also connect rectangular electric wire pipes.

[0006] Also, a pipe joint that connects a wavy shaped pipe, which has projecting portions and substantially square shaped cross sections in a pipe diameter direction thereof, with a tubular fitting portion of the pipe joint, which has a substantially square shaped cross section, by inserting an end of the pipe into the tubular fitting portion has been proposed (Patent Document 2).

[0007] In the pipe joint in Patent Document 2, a locking piece made of a thin metal plate is provided on an interior wall of the tubular fitting portion. The projecting portion of the wavy-shaped pipe presses and widen the locking piece outward resisting its elastic force and allowing insertion of the wavy-shaped pipe into the tubular fitting portion. At this time, elastic return force of the locking piece makes the locking piece fit into a gap between the adjacent projecting portions of the wavy-shaped pipe being inserted into the tubular fitting portion to be locked to the projecting portion. This can prevent the wavy-shaped pipe from pulling out from the tubular fitting portion. Thus, this can prevent pulling out of the wavy-shaped pipe as well as facilitate connection operation, and, also, projecting outward of the wavy-shaped pipe beyond the projecting portions can be suppressed as much as possible.

[0008] Also, a pipe joint using a stopper ring including a plurality of stopper members provided continuously in a circumference direction thereof and projecting locking claws provided on an outer periphery surface thereof has been proposed (Patent Document 3, for example).

[0009] In Patent Document 3, the stopper ring in which a plurality of the stopper members are provided continuously in its circumference direction is mounted on a recessed portion on an outer periphery surface at a pipe end portion of a wavy shaped pipe made of synthetic resin. The pipe joint is provided with a socket portion made of synthetic resin, which accommodates the pipe end portion of the wavy shaped pipe made of synthetic resin with the stopper ring being mounted. Also, through holes are formed on a peripheral wall of the socket portion at positions corresponding to the locking claws. When the pipe end portion of the wavy shaped pipe made of synthetic resin is inserted into the pipe joint according to Patent Document 3, the locking claws are engaged with opening edge portions of the through holes and this serves to stop the wavy shaped pipe made of synthetic resin from being pulled out.

[0010] Also, a halved-shaped joint member with a substantially rectangular outer shape can be used. In this case, the joint member is formed so as to cover large-diameter portions of an electric wire pipe, which face each other with a small-diameter portion therebetween, as a whole. Leg portions for fitting are provided on end portions for fitting of one half of the joint member, and the leg portions are fitted into grooves formed on end portions of the other half to be fixed with each other. Also, non-woven water-expansion cloth may be stuck onto an inner periphery surface of the small-diameter portion of the joint member.

[0011] Also, in addition to the above, there are a pipe joint provided with a plate spring inclining and standing on an inner face on an opening side of a rectangular tubular portion thereof (Patent Document 4), and a pipe joint for connecting the pipe bodies by pressing a pipe body into one end and spirally rotating and screwing another pipe body into the other end (Patent Document 5). Furthermore, there is a pipe joint having a fixing portion, which contains a locking member and a plate spring inside the pipe joint, on one end and a bell mouth on the other end (Patent Document 6).

RELATED ART PATENT DOCUMENTS

[0012]

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2000-337573 (JP-A-2000-337573)

[Patent Document 2] Japanese Unexamined Patent Application Publication No. 2005-172233 (JP-A-2005-172233)

[Patent Document 3] Japanese Unexamined Patent Application Publication No. 2010-270879 (JP-A-2010-270879)

[Patent Document 4] Japanese Unexamined Patent Application Publication No. 2009-250309 (JP-A-2009-250309)

[Patent Document 5] Japanese Unexamined Patent Application Publication No. 2004-007996 (JP-A-2004-007996)

[Patent Document 6] Japanese Unexamined Patent Application Publication No. 2007-037266 (JP-A-2007-037266)

SUMMARY OF THE INVENTION (PROBLEMS TO BE SOLVED BY THE INVENTION)

[0013] However, connection operation is troublesome in a method using bolts as in Patent Document 1. Thus, a pipe joint that can be fixed to an electric wire pipe in a single operation without using bolts or nuts and that cannot be easily detached has been desired.

[0014] Also, the stopper mechanism of the pipe joint in Patent Document 2 is complicated and is not a one-touch joint that can be easily fixed to electric wire pipes. Also, fixing of the locking pieces to the pipe joint is troublesome in manufacturing the pipe joint. Also, when a large pulling out force is applied to the pipe joint, there is a possibility that a part connecting the pipe joint and the locking piece may buckle.

[0015] Also, in Patent Document 3, the locking claws are formed on an end of a wavy pipe that is to be inserted. However, similarly to Patent Document 2, due to use of the locking claw, there is a possibility that a part connecting the pipe joint and the locking piece may buckle when a large pulling out force is applied to the pipe joint.

[0016] In such a structure, it is necessary to provide a barb portion at a tip end of the leg portion for fitting. Since this barb portion protrudes outside a contour of the pipe joint, the pipe joint may come off in a case in which the pipejoint receives a shock from outside or the like.

[0017] The mechanism using a plate spring as in Patent Document 4 and Patent Document 6 is also complicated. Also, the pipe joint in Patent Document 5 can connect only the pipes having spirally formed convexo-concave.

[0018] The present invention was made in view of such problems. Its object is to provide a pipe joint of a simple structure that can connect with a small-diameter portion of a rectangular electric wire pipe in a single operation without using bolts or nuts, and a connection structure for a rectangular electric wire pipe and a pipe joint.

(MEANS FOR SOLVING PROBLEMS)

[0019] To achieve the above object, a first invention is a pipe joint that connects with a pipe-body small-diameter portion of a rectangular electric wire pipe. The rectangular electric wire pipe includes a plurality of pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and pipe-body small-diameter portions, which are circular shaped valley parts. The pipe-body large-diameter portions and the pipe-body small-diameter portions are formed alternately on an outer periphery surface of a pipe body between a male fitting portion and a female portion that are formed on end parts of the pipe body. At least one side of the rectangular electric wire pipe is cut at the pipe-body small-diameter portion. The pipe joint includes a joint body and a -shaped fixing member. The f-shaped fixing member includes a top surface portion and a pair of leg portions. The leg portions are connected to both end portions of the top surface portion projecting downward at substantially right angles to the top surface portion, and, below the top surface portion, the step portions protruding outward from connecting portions between each of the leg portions and the top surface portion are formed respectively. A small-diameter-portion fixing portion for fixing the pipe-body small-diameter portion is formed on at least one side of the joint body, and the small-diameter-portion fixing portion includes a tubular portion into which the pipe-body large-diameter portion is to be inserted and a cylindrical portion, which is disposed on a farther deep side of the tubular portion. The pipe-body large-diameter portion is disposed on each side of the pipe-body small-diameter portion interposing the same. A cutout portion is formed at a part of the tubular portion. The cutout portion opens up an upper part of a substantially rectangular shaped portion of a side face and a top face of the tubular portion. At the time of inserting the -shaped fixing member from above into the cutout portion, the step portion of the -shaped fixing member is mounted on an upper portion of a side face of the tubular portion being cut out, and the leg portions of the -shaped fixing member are inserted into opening portions provided on both sides of a bottom portion of the tubular portion of the joint body to fix the -shaped fixing member to thejoint body.

[0020]

An engaging step portion may be formed inside a side face of the tubular portion at a position corresponding to the cutout portion of thejoint body.

[0021] An engaging portion directing outward of the leg portion may be formed at a predetermined position below the step portion of thef-shaped fixing member, and the engaging step portion and the engaging portion may engage with each other vertically.

[0022] An internal periphery surface of the top surface portion of the -shaped fixing member may be either in a substantially arc shape or an arch shape.

[0023] It is preferable that the leg portions of the -shaped fixing member do not protrude to an outer face of the bottom portion when the leg portions are inserted into the opening portions of the small-diameter-portion fixing portion of the joint body.

[0024] A water sealing member may be disposed on a farther deep side of the cutout portion in the small-diameter-portion fixing portion of the joint body so as to surround an entire periphery of an inner periphery surface of the tubular portion.

[0025] Each side of the joint body may have the small-diameter-portion fixing portion for fixing the pipe-body small-diameter portion and the cylindrical portion, which are formed so as to face each other symmetrically, and the -shaped fixing member may be inserted into the cutout portion of each of the tubular portions to fix the fl-shaped fixing member to the joint body.

[0026] One side of the joint body may have the small-diameter-portion fixing portion for fixing the pipe-body small-diameter portion and the cylindrical portion, and a male fitting portion that is to be fixed to a female fitting portion may be formed on the other side of the joint body.

[0027] The male fitting portion may include a pair of locking walls being disposed separately in the pipe axial direction and a ring member being disposed in a region between the locking walls. The ring member is substantially C-shaped with a part in a circumference direction being cut. The ring member includes a reduced diameter portion at one end part thereof and a plurality of click portions being provided side by side separately with slits therebetween to the reduced diameter part in a circumference direction of the ring member, and an outer diameter of the click portion gradually increases from the reduced diameter portion toward a tip end thereof. The ring member is disposed so a tip end of the click portion is positioned on a deeper side of the pipe body and the reduced diameter portion is positioned on a tip end side of the pipe body. A large-diameter portion is formed on the tip end side of the pipe body in the region between the locking walls, a small-diameter portion is formed on the base side of the pipe body in the region between the locking walls, and a slope portion is formed between the large-diameter portion and the small-diameter portion. There may be a clearance between the ring member and at least one of the locking walls and the ring member can slide in an axial direction within the region between the locking walls.

[0028] The male fitting portion may include a pair of locking walls being disposed separately in the pipe axial direction and a ring member being disposed in a region between the locking walls. The ring member is substantially C-shaped with a part in a circumference direction being cut. The ring member includes a reduced diameter portion at one end part thereof, a plurality of click portions being provided side by side separately with slits therebetween to the reduced diameter part in a circumference direction of the ring member, and a slide guide, protruding parallel to the pipe axial direction from the reduced diameter portion, being formed at a part of circumference periphery of the reduced diameter portion where the click portions are not provided. An outer diameter of the click portion gradually increases from the reduced diameter portion toward a tip end thereof. The ring member is disposed so a tip end of the click portion is positioned on a deeper side of the pipe body and the reduced diameter portion is positioned on a tip end side of the pipe body. The region between the locking walls is formed in a straight pipe shape. There may be a clearance between the ring member and at least one of the locking walls, the ring member can slide in an axial direction within the region between the locking walls, and the slide guide and the locking walls may restrict movement of the ring member.

[0029] A first connecting portion and a second connecting portion may be formed on both end portions in a circumference direction of the reduced diameter portion, and the connecting portions are connected with each other to form the ring member into a ring shape.

[0030] The water sealing member may be either a water expansion non-woven cloth including polyester fiber, sodium polyacrylate, and binder resin or rubber packing.

[0031] Each of the joint body and the -shaped fixing member may be preferably made of any one of high density polyethylene, polypropylene, ABS resin, PC resin, or polymer alloy of ABS resin or PC resin.

[0032] According to the first invention, simply inserting the -shaped fixing member with the rectangular electric wire pipe being inserted into one of the small-diameter-portion fixing portion of the joint body can fix the rectangular electric wire pipe to the pipe joint. Thus, the rectangular electric wire pipe can be fixed to the pipe joint in a single operation without using bolts or nuts.

[0033] Also, the engaging step portion formed inside a side face of the tubular portion at a position corresponding to the cutout portion of the joint body can serve as an engaging portion for the f-shaped fixing member. For example, if the engaging portion directing outward of the leg portion is formed at a predetermined position below the step portion of the -shaped fixing member, the above-mentioned engaging step portion and the engaging portion can engage with each other vertically and this can give function for preventing the -shaped fixing member from being pulled out.

[0034] Also, the internal circumference surface of the top surface portion of the fl-shaped fixing member is formed either in a substantially arc shape or an arch shapesoastobeinashape corresponding to the circular small-diameter portion of the rectangular electric wire pipe.

[0035] Also, when the leg portions are inserted into the opening portions of the small-diameter-portion fixing portion, the leg portions of thef-shaped fixing member do not protrude to an outer face of the bottom portion, and thus the fl-shaped fixing member does not come into contact with the other members. Thus, even when the pipe joint hits against other members, the -shaped fixing member does not come off.

[0036] Also, the water sealing member is disposed on a farther deep side of the cutout portion in the tubular portion of the joint body, surrounding an entire periphery of an inner periphery surface of the tubular portion, to ensure water sealing performance of the gap between the rectangular electric wire pipe and the pipe joint.

[0037] Also, forming the small-diameter-portion fixing portion and the cylindrical portion on each side of the joint body so as to face each other symmetrically makes it possible to similarly fix the small-diameter portion of the rectangular electric wire pipe to each side of the joint body.

[0038] Also, providing the male fitting portion on the other end portion of the joint body facilitates connection with another female fitting portion.

[0039] Also, since the male fitting portion includes the ring member that is disposed on the outer face of the male fitting portion, the ring member can be easily visually recognized. Also, when fitting the female fitting portion and the male fitting portion, the ring member can move over the large-diameter portion of the two-step structure of the male fitting portion. Furthermore, when the male fitting portion is pushed into the female fitting portion, an end portion of the female fitting portion eventually comes to contacts the click portion of the ring member so that the ring member retains the male fitting portion to the female fitting portion and the male fitting portion works effectively on connection of the rectangular electric wire pipes.

[0040] Also, the slide guides projecting parallel to the pipe axial direction from the reduced diameter portion are formed at parts of the ring member where the click portions are not provided. This can prevent the ring member from inclining when being attached to the male fitting portion and allow the ring member to slide straight over the male fitting portion in the pipe axial direction. When the ring member slides and moves between a pair of the locking walls, the slide guides are locked at coming into contact with the locking walls. Thus, the ring member never comes off the electric wire pipe.

[0041] Also, forming the first and second connecting portions on both end portions in circumference direction of the reduced diameter portion allows the ring member to be formed into a ring so as to prevent the ring member from coming off. Furthermore, adjusting the connection position of the ring member connecting portions enables to adjust the periphery length of the reduced diameter portion of the ring member.

[0042] Also, using a water expansion member or rubber packing as the water sealing member can ensure the water sealing performance with certainty.

[0043] Also, choosing material for the joint body and the 1-shaped fixing member from any of high density polyethylene, polypropylene, ABS resin, PC resin, or polymer alloy of ABS resin or PC resin, respectively, can ensure sufficient rigidity.

[0044] A second invention is a connection structure for rectangular electric wire pipes and a pipe joint in which a rectangular electric wire pipe being cut at the pipe-body small-diameter portion is connected to each end portion of the pipe joint according to the first invention. The rectangular electric wire pipe includes a plurality of the pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions, which are circular shaped valley parts. The pipe-body large-diameter portions and the pipe-body small-diameter portions are formed alternately on an outer periphery surface of the pipe body.

[0045] According to the second invention, the rectangular electric wire pipes with the pipe-body large-diameter portions and the pipe-body small-diameter portions that are formed alternately are cut at the pipe-body small-diameter portions thereof, and the cut pipe-body small-diameter portions of the rectangular electric wire pipes can be connected with each other with certainty.

[0046] A third invention is a connection structure for rectangular electric wire pipes and a pipe joint, in which one end portion of the pipe joint according to the first invention is connected with an rectangular electric wire pipe being cut at the pipe-body small-diameter portion. The rectangular electric wire pipe includes a plurality of the pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions, which are circular shaped valley parts. The pipe-body large-diameter portions and the pipe-body small-diameter portions are formed alternately on an outer periphery surface of the pipe body. The male fitting portion on the other end portion of the pipe joint is connected with the female fitting portion formed on an inner periphery part of the pipe body. The female fitting portion includes, from the tip end side, in sequence, a female-side tubular portion, a female-side slope portion whose diameter gradually decreases from the female-side tubular portion, and a ring fitting portion whose diameter increases from a minimum inner diameter part of the female-side slope portion.

[0047] According to the third invention, the rectangular electric wire pipe is cut at the pipe-body small-diameter portion thereof, and the cut pipe-body small-diameter portion of the rectangular electric wire pipes can be connected with the female fitting portion with certainty.

[0048] A fourth invention is a connection structure for rectangular electric wire pipes and a pipe joint, in which one end portion of the pipe joint according to the first invention is connected with an rectangular electric wire pipe being cut at the pipe-body small-diameter portion. The rectangular electric wire pipe includes a plurality of the pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions, which are circular shaped valley parts. The pipe-body large-diameter portions and the pipe-body small-diameter portions are formed alternately on an outer periphery surface of the pipe body. The male fitting portion on the other end portion of the pipe joint is connected with the female fitting portion formed on an inner periphery part of the pipe body. The female fitting portion includes, from the tip end side, in sequence, a female-side tubular portion, a female-side slope portion whose diameter gradually decreases from the female-side tubular portion, and a ring fitting portion whose diameter increases from a minimum inner diameter part of the female-side slope portion.

[0049] According to the fourth invention, the same effects as in the third invention can be obtained. At this time, the slide guides projecting parallel to the pipe axial direction from the reduced diameter portion are formed at parts of the ring member where the click portions are not provided. This can prevent the ring member from inclining when being attached to the male fitting portion and allow the ring member to slide over the male fitting portion straight in the pipe axial direction.

[0050] A fifth invention is a connection structure for rectangular electric wire pipes and a pipe joint, in which one end portion of the pipe joint according to the first invention is connected with an rectangular electric wire pipe being cut at the pipe-body small-diameter portion. The rectangular electric wire pipe including a plurality of the pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions, which are circular shaped valley parts. The pipe-body large-diameter portions and the pipe-body small-diameter portions are formed alternately on an outer periphery surface of the pipe body. The male fitting portion on the other end portion of the pipe joint is connected with the female fitting portion formed on an inner periphery part of the pipe body. The female fitting portion includes, from the tip end side, in sequence, a female-side tubular portion, a female-side slope portion whose diameter gradually decreases from the female-side tubular portion, and a ring fitting portion whose diameter increases from a minimum inner diameter part of the female-side slope portion.

[0051] According to the fifth invention, the same effects as in the third invention can be obtained. At this time, forming the first and second connecting portions on both end portions in a circumference direction of the reduced diameter portion allows the ring member to be formed into a ring so as to prevent the ring member from coming off. Furthermore, adjusting the connection position of the ring member connecting portions enables to adjust the periphery length of the reduced diameter portion of the ring member.

(EFFECTS OF THE INVENTION)

[0052] The present invention can provide a pipe joint of a simple structure that can connect with a small-diameter portion of a rectangular electric wire pipe in a single operation without using bolts or nuts, and a connection structure of a rectangular electric wire pipe and a pipe joint.

BRIEF DESCRIPTION OF DRAWINGS

[0053] FIG. 1 is an exploded perspective view of a pipe joint 1. FIG. 2 (a) is a side view of ajoint body 3. FIG. 2 (b) is a bottom view of the joint body 3. FIG. 3 (a) is a side view of the pipe joint 1. FIG. 3 (b) is a cross sectional view of FIG. 3 (a).

FIG. 4 is an assembled perspective view of the pipe joint 1. FG. 5 (a) and (b) are views showing a method of connecting a cut rectangular electric wire pipe 40 and a small-diameter-portion fixing portion 2. FG. 6 (a) and (b) are views showing a method of connecting the cut rectangular electric wire pipe 40 and the small-diameter-portion fixing portion 2. FIG. 7 (a) is a cross sectional view taken along K-K line in FIG. 6 (a). FIG. 7 (b) is a cross sectional view taken along L-L line in FIG. 6 (a). FIG. 8 is an exploded perspective view of a pipe joint la. FIG. 9 is an assembled perspective view of the pipe joint la. FIG. 10 (a) and (b) are views showing a method of connecting the cut rectangular electric wire pipe 40 with the others. FIG. 11 (a) and (b) are views showing a method of connecting the cut rectangular electric wire pipe 40 with the others. FIG. 12 is an exploded perspective view of a pipe joint 1b. FIG. 13 (a) is a side view of ajoint body 3b. FIG. 13 (b) is a bottom view of the joint body 3b. FIG. 14 (a) is a side view of the pipe joint 1b. FIG. 14 (b) is a cross sectional view of FIG. 14 (a). FIG. 15 is an enlarged cross sectional view of a male fitting portion 4. FIG. 16 is an enlarged cross sectional view of another embodiment of the male fitting portion 4. FIG. 17 is a partially enlarged cross sectional view of a ring member 6. FIG. 18 is a perspective view showing a ring member 6a. FIG. 19 is a perspective view showing a ring member 6b. FIG. 20 (a) is a perspective view of a ring member 6c. FIG. 20 (b) is an enlarged view of ring member connecting portions 63. FIG. 21 is a view showing a method of connecting the male fitting portion 4 and a female fitting portion 43. FIG. 22 (a) and (b) are views showing a method of connecting the male fitting portion 4 and the female fitting portion 43. FIG. 23 (a) is a view showing a method of connecting the male fitting portion 4 and the female fitting portion 43. FIG. 23 (b) is a view showing a connection structure 10 for the male fitting portion 4 and the female fitting portion 43. FIG. 24 is a view showing another embodiment of the connection structure 10 for the male fitting portion 4 and the female fitting portion 43.

FIG. 25 is a view showing another embodiment of the connection structure 10 for the male fitting portion 4 and the female fitting portion 43.

DESCRIPTION OF SOME EMBODIMENTS

[0054] Hereinafter, a pipe joint 1 according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an exploded perspective view showing the pipe joint 1. The pipe joint 1 for rectangular electric wire pipes mainly includes a joint body 3 and a -shaped fixing member 5. In the present embodiment, only one end portion side of the pipe joint 1 will be illustrated in the drawings. That is, in the present embodiment, a small-diameter-portion fixing portion 2, which fixes a pipe-body small-diameter portion that will be described below, is formed on at least one side of the joint body 3, and the other end portion of thejoint body 3 will not be particularly specified.

[0055] The f-shaped fixing member 5 includes a top surface portion 7 and a pair of leg portions 9. The leg portions 9 are connected in vicinity of both end portions of the top surface portion 7, projecting downward at substantially right angles to the top surface portion 7. On each side portion of thef-shaped fixing member 5, a step portion 11 is provided. The step portion 11 is formed directing downward with an upper part thereof extending toward each side direction. That is, below the top surface portion 7, the step portions 11 protruding outward from connecting portions between each of the leg portions 9 and the top surface portion 7 are formed respectively. The step portion 11 is formed substantially parallel to a pipe axial direction of the joint body 3.

[0056] Engaging portions 27 directing outward of the leg portions 9 are formed at predetermined positions of the f-shaped fixing member 5 below the step portions 11. The engaging portions 27 are formed so that lower parts thereof extend toward both sides. The engaging portion 27 and the step portion 11 are formed substantially parallel to each other.

[0057] An internal periphery surface of the top surface portion 7 of the -shaped fixing member 5 is either in a substantially arc shape or an arch shape. The shape of the internal periphery surface of the top surface portion 7 corresponds to an outer shape of a small-diameter portion of a rectangular electric wire pipe that will be described below.

[0058] FIG. 2 (a) is a side view of the joint body 3, FIG. 2 (b) is a bottom view of the joint body 3, FIG. 3 (a) is a plan view of the joint body 3, and FIG. 3 (b) is a cross sectional view taken along X-X line in FIG. 3 (a). The small-diameter-portion fixing portion 2 of the joint body 3, to which the small-diameter portion is to be fixed, includes a cylindrical portion 13 and a substantially rectangular shaped tubular portion 15. The cylindrical portion 13 is a part in which a small-diameter portion of a rectangular electric wire pipe, which will be described below, is to be inserted. Also, the tubular portion 15 is a part in which a large-diameter portion of a rectangular electric wire pipe and the like, which will be described below, are to be inserted. That is, the small-diameter-portion fixing portion 2 includes the tubular portion 15 in which a large-diameter portion of a rectangular electric wire pipe, which will be described below and is disposed on each side of the small-diameter portion of the pipe body of a rectangular electric wire pipe interposing the small-diameter portion of the pipe body, is to be inserted, and, in addition, the cylindrical portion 13 that is disposed on a farther deep side of the tubular portion 15.

[0059] A cutout portion 17, which opens up an upper part of a substantially rectangular shaped side face 19 and a top face 21, is formed at a part of the tubular portion 15. Also, an engaging step portion 25 is formed inside the side face 19 of the tubular portion 15 at a position corresponding to the cutout portion 17 of the joint body 3. The engaging step portion 25 is formed substantially parallel to the pipe axial direction of the joint body 3 as a projecting portion that protrudes inward.

[0060] Opening portions 23 are provided on both sides of a substantially rectangular bottom portion 29 of the tubular portion 15 of the joint body 3. The opening portions 23 are formed at positions corresponding to the cutout portion 17 in regard to the pipe axial direction of the joint body 3. The leg portions 9 of the 1-shaped fixing member 5 can be inserted into the opening portions 23.

[0061] Also, as shown in FIG. 3 (b), on a deeper side of the cutout portion 17 in the tubular portion 15 of the joint body 3, a water sealing member 31 is disposed so as to surround an entire periphery of an inner periphery surface of the tubular portion 15. The water sealing member 31 is a water expansion member, for example, and in such a case, a non-woven cloth including polyester fiber, sodium polyacrylate fiber, and binder resin can be applied. Also, the water-sealing member 31 may be rubber packing, and, in such a case, a groove is formed on the inner periphery surface of the tubular potion 15 and the rubber packing is fitted into the groove.

[0062] Each of the joint body 3 and the -shaped fixing member 5 is preferably made of any one of high density polyethylene, polypropylene, ABS resin, PC resin, or polymer alloy of ABS resin or PC resin.

[0063] FIG. 4 is an assembled perspective view of the pipe body 1. The -shaped fixing member 5 is inserted from an upper part of the joint body 3 into the cutout portion 17. At this time, the step portions 11 of the -shaped fixing member 5 are mounted on upper portions of the side faces 19 of the tubular portion 15. Also, tip ends of the leg portions 9 of the -shaped fixing member 5 are inserted into the opening portions 23 that are provided on both sides of the bottom portion 29 of the tubular portion 15 of the joint body 3. As above, the -shaped fixing member 5 is fixed to the joint body 3.

[0064] When the leg portions 9 of the f-shaped fixing member 5 are inserted into the cutout portion 17, the engaging portion 27, which protrudes out of the leg portion 9 and is formed directing upward, come to contact with the engaging step portion 25, which is formed directing downward at an inner surface of a part corresponding to the cutout portion 17 of the joint body 3. At this time, because the -shaped fixing member 5 is made of resin, a distance between the leg portions 9 is reduced due to elastic deformation. When the f-shaped fixing member 5 is inserted further into the cutout portion 17 and the engaging portion 27 climes over the engaging step portion 25, the leg portions 9 widen due to elastic force so that the tip positions of the leg portions 9 coincide with the positions of the opening portions 23 and thus the fl-shaped fixing member 5 is inserted into the opening portions 23. At this time, the engaging step portion 25 and the engaging portion 27 engage with each other vertically.

[0065] When the leg portions 9 of thef-shaped fixing member 5 are inserted into the opening portions 23 of the joint body 3, tip ends of the leg portions 9 do not protrude to an outer face of the bottom portion 29. That is, a length from the step portion 11 to the tip end of the leg portion 9 of the -shaped fixing member 5 is less than a distance between an upper edge portion of the cutout portion 17 on the side face 19, which comes to contact with the step portion 11, and a lower surface of the bottom portion 29. In this way, it is possible to prevent the tip ends of the leg portions 9 from protruding from the bottom portion 29 and contacting with other members or the like. Thus, when the rectangular electric pipes are stacked up, the tip ends of the leg portions 9 of the 1-shaped fixing member 5 do not come into contact with the rectangular electric pipe on the lower layer or the like, and there will be no chance that the 1-shaped fixing member 5 comes out of the opening portions 23 due to backlash from the contact.

[0066] Next, a method for connecting a cut rectangular electric wire pipe 40 and the pipe joint 1 will be described. As shown in FIG. 5 (a), in the rectangular electric wire pipe 40, a plurality of pipe-body large-diameter portions 44, which are substantially rectangular shaped mountain parts, and pipe-body small-diameter portions 45, which are circular shaped valley parts, are formed alternately on an outer periphery surface of a pipe body between a male fitting portion (whose illustration is omitted) and a female fitting portion (whose illustration is omitted) that are formed on end parts of the pipe body. Providing the substantially square shaped pipe-body large-diameter portion 44 in this way allows the rectangular electric wire pipes 40 to be disposed stably when the rectangular electric wire pipes 40 are stacked up.

[0067] In the present embodiment, at least one side of the rectangular electric wire pipe 40 is cut at the pipe-body small-diameter portion 45, and this cut pipe-body small-diameter portion 45 is connected with the pipe joint 1. First, as shown in FIG. (a), the rectangular electric wire pipe 40 is cut into a predetermined length and the cut end part (the pipe-body small-diameter portion 45) is disposed to face the small-diameter-portion fixing portion 2 of the pipe joint 1. Next, the pipe-body small-diameter portion 45 is inserted into the small-diameter-portion fixing portion 2 of the pipe joint 1 (in a direction shown by an arrow P in the drawing).

[0068] FIG. 5 (b) is a view showing a state in which the rectangular electric wire pipe is inserted into the small-diameter-portion fixing portion 2. A size of an opening diameter of the tubular portion 15 is made to be capable of accommodating the pipe-body large-diameter portion 44. Furthermore, a length of the tubular portion is made to be substantially equivalent to an entire length of a pair of the pipe-body large-diameter portions 44 interposing the pipe-body small-diameter portion 45. Also, a diameter of the cylindrical portion 13 is made to be larger than that of the pipe-body small-diameter portion 45 of the rectangular electric wire pipe and to be smaller than that of the pipe-body large-diameter portion 44. Also, a length of a portion with circular cross section in the cylindrical portion 13 is made to be equivalent to or larger than a length of the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40.

[0069] Setting the length of the circular cross section of the cylindrical portion in this way makes it possible to connect a rectangular electric wire pipe that is cut at any position of the pipe-body small-diameter portion 45.

[0070] As above, a cut portion of the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40 is inserted into the cylindrical portion 13 of the small-diameter-portion fixing portion 2 toward a deep side of the pipe axial direction and disposed. Also, inside the tubular portion 15 of the small-diameter-portion fixing portion 2, at least the pipe-body large-diameter portion 44, the pipe-body small-diameter portion 45, and the pipe-body large-diameter portion 44 of the rectangular electric wire pipe 40 are disposed in sequence, and the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40 is disposed at a position of the cutout portion 17 of the tubular portion 15.

[0071] Also, as mentioned above, the water sealing member 31 is disposed in the tubular portion 15 at the small-diameter-portion fixing portion 2, which is on a deeper side of the cutout portion 17, so as to surround an entire periphery of an inner periphery surface of the tubular portion 15. Thus, the inner face of the small-diameter-portion fixing portion 2 and the outer face of the pipe-body large-diameter portion 44 of the rectangular electric wire pipe 40 are in close contact by means of the water sealing member 31 and water sealing performance is ensured.

[0072] Next, the 1-shaped fixing member 5 is inserted into the cutout portion 17 from the upper part of the small-diameter-portion fixing portion 2. FIG. 6 (a) is a view showing a state before inserting the 1-shaped fixing member 5, and FIG. 6 (b) is a view showing a state after inserting the 1-shaped fixing member 5. Also, FIG. 7 (a) is a cross sectional view taken along K-K line in FIG. 6 (a), and FIG. 7 (b) is a cross sectional view taken along L-L line in FIG. 6 (b).

[0073] As shown in FIG. 6 (b) and FIG. 7 (b), the -shaped fixing member 5 is inserted into the cutout portion 17 from above and the step portion 11 of the fl-shaped fixing member 5 is mounted on an upper portion of a side face of the tubular portion 15. That is, the step portion 11 that is formed on the upper part of the leg portion 9 of the -shaped fixing member 5 is made to contact with the upper part of the side face of the cutout portion 17, and the -shaped fixing member 5 is mounted on the upper part of the side face of the tubular portion 15 so that a side face of the top surface portion 7 is in contact with a side face of the pipe-body large-diameter portion 44 of the rectangular electric wire pipe 40. In this state, the tip ends of the leg portions 9 of the -shaped fixing member 5 are inserted into the opening portions 23 that are provided on both sides of the bottom portion 29 of the tubular portion 15 of the small-diameter-portion fixing portion 2, and thus the fl-shaped fixing member 5 is fixed to the small-diameter-portion fixing portion 2.

[0074] At this time, the inner periphery face of the top surface portion 7 of the fl-shaped fixing member 5 is formed into a shape that matches the circular shaped pipe-body small-diameter portion 45 or a shape that is smaller than the pipe-body large-diameter portion 44 and does not interfere with the pipe-body small-diameter portion 45. Thus, the inner periphery face of the top surface portion 7 of the f-shaped fixing member 5 can come into contact with at least a part of an upper part of a circular cross section of the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40, or the substantially arc shape thereof that matches the pipe-body small-diameter portion 45 can come into contact with the pipe-body small-diameter portion 45 as if covering the same.

[0075] When the f-shaped fixing member 5 is mounted on the upper part of the side face of the cutout portion 17, the inner periphery surface of the top surface portion 7 of the f-shaped fixing member 5 may be smaller than the pipe-body large-diameter portion 44 of the rectangular electric wire pipe 40 inside and larger than the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40. In this case, the f-shaped fixing member 5 is kept a predetermined distance apart from the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40 so as not to interfere therewith and is in a shape covering and surrounding the upper part of the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40. That is, the -shaped fixing member 5 inserted into the cutout portion 17 may be or may not be in contact with the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40. Here, the side face part of the top surface portion 7 of the f-shaped fixing member 5 has an outer periphery surface and the inner periphery surface and may be formed into a rib structure, in which the interior part surrounded by both surfaces are sunken. Alternatively, the side face portion of the top surface portion 7 may be formed into a flat surface and the top surface portion 7 may be formed into a bulk shape. Forming the top surface portion 7 into a bulk shape as above can increase an area of pressure-receiving surface that receives pulling out force when pulling out force is applied onto the rectangular electric wire pipe 40.

[0076] When the f-shaped fixing member 5 is pushed until the step portions 11 are in contact with edge portions of the cutout portion 17, the engaging portions 27 of the f-shaped fixing member 5 engage with the engaging step portions 25. Thus, the fl-shaped fixing member 5 is fixed to the small-diameter-portion fixing portion 2, and thef-shaped fixing member 5 never comes out of the small-diameter-portion fixing portion 2. Also, as mentioned above, in this state, the tip ends of the leg portions 9 of the f-shaped fixing member 5 do not protrude to the outer face of the bottom portion 29 of the small-diameter-portion fixing portion 2. Thus, it is possible to prevent the leg portions 9 from being in contact with other external members or the like.

[0077] When the rectangular electric wire pipe 40 is tried to be pulled out of the pipe joint 1 in a state in which the -shaped fixing member 5 is fixed to the small-diameter-portion fixing portion 2 as above, a part of the upper part of the inner surface of the top surface portion 7 of thef-shaped fixing member 5 and the leg portions 9 come to contact with and engage with the side faces of the substantially square shaped pipe-body large-diameter portion 44 of the rectangular electric wire pipe 40. As above, the rectangular electric wire pipe 40 engages with the pipe joint 1 in the pipe axial direction and thus the rectangular electric wire pipe 40 does not come out of the pipe joint 1.

[0078] As above, a connection structure 10a in which the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40 that is cut at the pipe-body small-diameter portion 45 is connected with the pipe joint 1 can be obtained.

[0079]

As above, according to the present embodiment, one of the end portions of the pipe joint 1 can be connected with the rectangular electric wire pipe 40 that is cut at the pipe-body small-diameter portion 45, in which the rectangular electric wire pipe includes the pipe-body large-diameter portions 44, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions 45, which are circular shaped valley parts, that are formed alternately on the outer periphery surface of a pipe body 49. At this time, fixing of the end portion of the pipe joint 1 with the rectangular electric wire pipe 40 that is cut at the pipe-body small-diameter portions 45 is performed by fitting thef-shaped fixing member 5 into the joint body 3. Thus, the cut portion at the pipe-body small-diameter portion of the rectangular electric wire pipe 40 can be easily connected to the pipe joint 1. At this time, connection operation can be completed in a single operation without using bolts or nuts so the connection operation is easy.

[0080] Also, at the connection part with the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40, the step portion 11 is formed at a lower part of the top surface portion 7 of thef-shaped fixing member 5 and the step portion 11 is made to be in contact with an upper part of the cutout portion 17. This makes it possible to easily grasp an insertion margin for the -shaped fixing member 5. Thus, there will be no such cases in which the -shaped fixing member 5 is inserted into the small-diameter-portion fixing portion 2 excessively, pressing the rectangular electric wire pipe 40. Also, since the step portions 11 are formed on the leg portions 9 reinforcing cross sections of the leg portions 9, thef-shaped fixing member 5 is stable and never buckles in an axial direction.

[0081] Also, the tip ends of the leg portions 9 of the -shaped fixing member 5 do not protrude from the small-diameter-portion fixing portion 2 to the outer face so the leg portions 9 are prevented from contacting with the other external members. Thus, it is possible to prevent the leg portions 9 from being pushed back into the small-diameter-portion fixing portion 2, and to prevent thef-shaped fixing member from being pulled out or damaged. Thus, even when the pipe joint 1 hits against other members, the rectangular electric wire pipe 40 never comes out of the small-diameter-portion fixing portion 2.

[0082] Also, the f-shaped fixing member 5 and the small-diameter-portion fixing portion 2 are fixed with certainty by engaging the engaging step portions 25 and the engaging portions 27. Thus, the 1-shaped fixing member 5 is never pulled out of the small-diameter-portion fixing portion 2.

[0083] Also, disposing the water sealing member 31 on the deeper side of the tubular portion 15 (on the side of the cylindrical portion 13) can ensure water sealing performance between the outer periphery surface of the pipe-body large-diameter portion 44 of the rectangular electric wire pipe 40 to be connected and the tubular portion 15. This can stop water entering into the cylindrical portion 13.

[0084] Also, since the side face of the 1-shaped fixing member 5 is in contact with the side face of the pipe-body large-diameter portion 44 that is disposed on the deeper side of the tubular portion 15, the rectangular electric wire pipe 40 is never pulled out of the small-diameter-portion fixing portion 2. At this time, since the leg portions 9 are inserted into the opening portions 23, deformation of the leg portions 9 is suppressed when pulling out force is applied to the rectangular electric wire pipe 40.

[0085] Next, a second embodiment will be described. FIG. 8 is an exploded perspective view showing a pipe joint la according to the second embodiment, and FIG. 9 is an assembled perspective view of the pipe joint la. In the descriptions below, the same notations will be used for those having the same functions as in the first embodiment shown in FIG. 1 to FIG 8. and redundant descriptions will be omitted.

[0086] The pipe joint la has approximately the same structure as the pipe joint 1 except that a joint body 3a has the small-diameter-portion fixing portions 2 formed on both ends thereof. That is, the joint body 3a includes the cylindrical portion 13 in the middle and the substantially rectangular tubular portions 15 that are disposed symmetric to the pipe axial direction, facing each other with the cylindrical portion 13 therebetween. The tubular portions 15 on both ends are in the same form, being symmetric with the cylindrical portion 13 in the middle.

[0087] As mentioned above, the cutout portion 17, which opens up the upper part of the substantially rectangular shaped side face 19 and the top face 21 is formed at a part of the tubular portion 15. That is, in the pipe joint la, the cutout portions 17 are formed at two positions that are symmetric to each other in the pipe axial direction with the cylindrical portion 13 therebetween. The 1-shaped fixing member 5 is inserted from above into each of the cutout portions 17. That is, a pair of the 1-shaped fixing member 5 are used in the pipe joint la.

[0088] Next, a method for connecting the rectangular electric wire pipe 40 and the pipe joint la will be described. The rectangular electric wire pipes 40, each of which is cut at a substantially middle of the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40, are adjusted in lengths and then connected by the pipe joint la. First, as shown in FIG. 10 (a), the rectangular electric wire pipes 40 are cut into predetermined lengths and the cut end portions thereof (the pipe-body small-diameter portions 45) are disposed so as to face each other. Next, the pipe-body small-diameter portions 45 facing each other are inserted into both sides of the joint body 3a of the pipe joint 1 (in a direction shown by an arrow H in the drawing).

[0089] FIG. 10 (b) is a view showing a state in which the rectangular electric wire pipes 40 are inserted into both sides of the joint body 3a. The cut portions of the pipe-body small-diameter portions 45 of the rectangular electric wire pipe 40 are inserted into the cylindrical portion 13 of the joint body 3a from both ends of the joint body 3a toward a deep side of the pipe axial direction and disposed. That is, the cut end portions of the pipe-body small-diameter portions 45 of the rectangular electric wire pipe 40 are disposed facing each other in the cylindrical portion 13 of the joint body 3a. Also, inside the tubular portion 15 of the joint body 3a, at least the pipe-body large-diameter portion 44, the pipe-body small-diameter portion 45, and the pipe-body large-diameter portion 44 of the rectangular electric wire pipe 40 are disposed in sequence, and the pipe-body small-diameter portion 45 of the rectangular electric wire pipe 40 is disposed at a position of the cutout portion 17 of the tubular portion 15.

[0090] Also, as mentioned above, the water sealing member 31 is disposed in each of the tubular portions 15 of the joint body 3a, which is on a deeper side of the cutout portion 17, so as to surround the entire periphery of the inner periphery surface of the tubular portion 15. Thus, the inner face of the joint body 3a and the outer face of the pipe-body large-diameter portion 44 of the rectangular electric wire pipe 40 are in close contact by means of the water sealing member 31, and thus water sealing performance is ensured.

[0091] Next, the f-shaped fixing member 5 is inserted into each of the cutout portions 17 from the upper part of the joint body 3a. FIG. 11 (a) is a view showing a state before inserting the f-shaped fixing member 5, and FIG. 11 (b) is a view showing a state after inserting the -shaped fixing member 5. As shown in FIG. 11 (b), the f-shaped fixing member 5 is inserted into the cutout portion 17 from above and the step portion 11 of the -shaped fixing member 5 is mounted on the upper portion of the side face of the tubular portion 15. In this state, the tip ends of the leg portions 9 of the f-shaped fixing member 5 are inserted into the opening portions 23 that are provided on both sides of the bottom portion 29 of the tubular portion 15 of the joint body 3a, and thus the -shaped fixing member 5 is fixed to the joint body 3a.

[0092] When each of the f-shaped fixing members 5 is pushed until the step portion 11 is in contact with the edge portion of the cutout portion 17, the engaging portions 27 of thef-shaped fixing member 5 engage with the engaging step portions 25. At this time, the step portions 11 and the engaging portions 27 of the -shaped fixing members 5 interpose the side face of the joint body 3a from both sides by the edge portions of the cutout portions 17 and the engaging step portions 25, so the fl-shaped fixing members 5 is fixed to the joint body 3a and the -shaped fixing members 5 is never pulled out of the joint body 3a. Also, as mentioned above, in this state, the tips of the leg portions 9 of the -shaped fixing member 5 do not protrude to the outer face of the bottom portion 29 of the joint body 3a. Thus, it is possible to prevent the leg portions 9 from being in contact with other external members or the like.

[0093] As above, the pipe joint la connects the cutting sections of the rectangular electric wire pipes 40 that are cut at the pipe-body small-diameter portions 45. That is, a connection structure 60 for rectangular electric wire pipes and a pipe joint in which the pipe joint la connects a pair of the rectangular electric wire pipes 40 together canbe obtained.

[0094] According to the second embodiment, a structure that is similar to the first embodiment and is symmetric with the cylindrical portion 13 in the middle can be realized. Thus, the same effects as in the first embodiment can be obtained. As above, the pipe joint la can connect the pipe-body small-diameter portions 45 of a pair of the rectangular electric wire pipes 40 with the others.

[0095] Next, a third embodiment will be described. FIG. 12 is an exploded perspective view showing a pipe joint lb according to the third embodiment. FIG. 13 (a) is a side view of a joint body 3b and FIG. 13 (b) is a bottom view of the joint body 3b. In the perspective views, structures such as a ring member and the like that will be described below are omitted.

[0096] The pipe joint lb has almost the same structure as the pipe joint 1 except that the shape of the joint body 3b is different. On one side of the joint body 3b, the small-diameter-portion fixing portion 2 is formed. As mentioned above, the small-diameter-portion fixing portion 2 is a part that fixes the pipe-body small-diameter portion of the rectangular electric wire pipe. On the other side of the joint body 3b, a male fitting portion 4 is formed. The male fitting portion 4 serves as a fixing portion for a female fitting portion of the rectangular electric wire pipe, which will be described below. Between the small-diameter-portion fixing portion 2 and the male fitting portion 4 of thejoint body 3b, a connection wall 34 is formed perpendicular to the pipe axial direction of the joint body 3b. That is, the connection wall 34 connects the small-diameter-portion fixing portion 2 and the male fitting portion 4.

[0097] FIG. 14 (a) is a side view of the pipe joint lb and FIG. 14 (b) is a cross sectional view of the pipe joint 1b. Also, FIG. 15 is a partially enlarged cross sectional view of FIG. 14 (b). The small-diameter-portion fixing portion 2 has the same structure as in the above-mentioned pipe joint 1 and detailed descriptions thereof will be omitted.

[0098] The male fitting portion 4 includes a ring member 6 and a water sealing member 32. The male fitting portion 4 is formed on an outer periphery part in vicinity of one end portion of the pipe joint 1b. As shown in FIG. 15, at an end portion of the female fitting portion 4, a locking wall 8, a ring member mounting position 12, the locking wall 8, a water sealing member holder 26, and the locking wall 8 are formed in sequence from a tip end. In descriptions hereinafter, an opening side of the male fitting portion 4 (a direction shown by an arrow B in the drawing) is defined as a tip end side of the male fitting portion 4, and a side opposite thereto (a direction shown by an arrow A in the drawing) is defined as a base side of the male fitting portion 4. The locking wall 8 is a part having a larger diameter compared to its surroundings. A pair of the locking walls 8 are disposed separately in the pipe axial direction to restrict a range of motion of the ring member 6.

[0099] A region between the pair of the locking walls 8 becomes the ring member mounting position 12 on which the ring member 6 is to be disposed. That is, the male fitting part 4 includes the pair of locking walls 8 that are disposed separately in the pipe axial direction and the ring member 6 that is disposed on the region between the locking walls 8. The ring member mounting portion 12 includes a large-diameter portion 14, a slope portion 16, and a small-diameter portion 18, in sequence, from the tip end side of the male fitting portion 4. That is, the large-diameter portion 14 is formed on the tip end side of the male fitting portion 4 of the region between the pair of the locking walls 8, the small-diameter portion 18 is formed on the base side of the male fitting portion 4 of the region between the pair of the locking walls 8, and the slope portion 16 is formed between the large-diameter portion 14 and the small-diameter portion 18. An outer diameter of the large-diameter portion 14 is smaller than that of the locking wall 8 and larger than that of the small-diameter portion 18.

[0100] The water sealing member holder 26 is provided on the base side beyond the ring member mounting position 12. As shown in FIG. 15, the water sealing member holder 26 is a groove having a substantially rectangular cross section that is provided between the two locking walls 8. The water sealing member holder 26 holds the water sealing member 32. That is, the water sealing member 32 is provided on the farther base side beyond the locking wall 8 on the base side of the male fitting portion 4, and, furthermore, another locking wall 8 for restricting and fixing the movement of the water sealing member 32 is provided on the base side of the water sealing member 32. The water sealing member 32 is a ring shaped member. Although an inner diameter of the water sealing member 32 is smaller than an outer diameter of the water sealing holder 26, the diameter of the water sealing member is enlarged when the water sealing member 32 is attached to the water sealing holder 26. Thus, an inner surface of the water sealing member 32 closely contacts an outer surface of the water sealing member holder 26.

[0101] An inner periphery part of a cross section of the water sealing member 32 is in a straight form (having an approximately same diameter in the pipe axial direction) and an outer periphery part is formed so as to have a slope part from one end of the pipe axial direction to the other. As shown in FIG. 15, a maximum outer diameter part of the water sealing member 32 is disposed facing toward the base side of the male fitting portion 4. An outer diameter of the maximum outer diameter part is larger than a maximum diameter of the joint body 3b of the male fitting portion 4 and thus the water sealing member 32 protrudes outward in a diameter direction.

[0102] The water sealing member 32 made of either rubber or a water expansion member, for example, can be used. However, if the water sealing member 32 has a shape protruding outward in the diameter direction as shown in FIG. 15, the water sealing member 32 is preferably made of rubber. If the water sealing member 32 is made of rubber, ethylene propylene rubber is applicable, for example. Ethylene propylene rubber is a type of synthetic rubber obtained by copolymerization of ethylene and propylene. To allow vulcanization by a sulfur compound, ethylene propylene rubber is often used in a form of an EPDM (ethylene propylene diene monomer) rubber, which is a copolymer of ethylene propylene rubber and a little amount of diene monomer. Other than that, rubber such as SBR, CR, NBR, ACM rubber or EPDM/PP dynamically cross-linked elastomer may be used.

[0103] Although illustrations are omitted in the drawing, when the water sealing member 32 is made of the water expansion member, the water sealing member 32 absorbs water and can swell to fill a space between the water sealing member 32 and the female fitting portion or the water sealing member holder 26. Thus, in such a case, the diameter of the water sealing member 32 is not formed smaller than that of the water sealing member older 26 and can be provided parallel to the pipe axial direction on an outer periphery of the water sealing member holder 26. A non-woven cloth can be used as the water expansion member. Here, the non-woven cloth can be wrapped around the outer periphery of the water sealing member holder 26, and both ends of the non-woven cloth are overlapped and bonded together by using an adhesive agent or fixed to each other by using a tacker or the like. Alternatively, an adhesive layer can be formed on one surface of the non-woven cloth, which can be wrapped around the water sealing member holder 26 to be fixed. For example, a non-woven cloth formed of polyester fiber and sodium polyacrylate fiber may be used as the non-woven cloth. In this case, a ratio of polyester fiber and sodium polyacrylate fiber is such that, if the total of both is 100 % by mass, an amount of sodium polyacrylate is between 30% and 70%, or preferably between 50% and 70% by mass.

[0104] Here, it is preferable to add a binder resin, which is a resin having a low melting point, to the water expansion non-woven cloth. The ratio of the binder resin is preferably in a range between 1% and 10%, or more preferably between 1 and 5%, of the total of both the polyester fiber and the sodium polyacrylate fiber. As a binder resin, polyester with low melting point can be used, for example, and the non-woven cloth can be formed by using a needle punching method.

[0105] The ring member 6 is disposed on the ring member mounting position 12. The ring member 6 is substantially ring shaped and is substantially C shaped, a part of which is cut at end portion in periphery direction 65 in its circumference direction (see FIG. 14).

[0106] FIG. 17 is a view showing a detailed cross sectional shape of the ring member 6. One end side of the ring member 6 has a reduced diameter portion 22, which has an outer diameter smaller than the other parts. A plurality of click portions 24 are provided directing to the other end part of the ring member 6. The plurality of the click portions 24 are provided side by side separately with slits 38 therebetween in the circumference direction to the reduced diameter part 22 (see FIG. 14 (a)).

[0107] Also, the outer diameter of the click portion 24 increases gradually from the reduced diameter portion 22 toward a tip end thereof. That is, on a cross section taken in the pipe axial direction, the ring member 6 has a tapered portion 33 whose diameter decreases from the tip end of the click portion 24 toward the reduced diameter portion 22. The ring member 6 is in a sharp wedge shape, in which the internal periphery part thereof is bent and formed in two steps and the thickness decreases from the tip end of the click portion 24 toward the reduced diameter portion 22.

[0108] As shown in FIG. 15, in the ring member 6, the tip ends of the click portions 24 are positioned on the base side of the male fitting portion 4, and the reduced diameter portion 22 is disposed so as to face toward the tip end side of the male fitting portion 4. Since the inner diameter of the ring member 6 is smaller than the outer diameter of the locking wall 8, the ring member 6 is retained between the locking walls 8.

[0109] Any one of ABS resin (acrylonitrile butadiene styrene copolymer), PP resin, rigid polyvinyl chloride, a mixed resin of any of the above mixed with PC resin, or polymer alloy is applicable for the ring member 6, for example, and it is preferable to apply ABS resin.

[0110] As shown in FIG. 15, a length of the ring member 6 in the pipe axial direction (C in the drawing) is less than a length of the ring member mounting position 12 (D in the drawing, which is the sum of lengths of the large-diameter portion 14, slope portion 16, and the small-diameter portion 18). Also, the length of the ring member 6 in the pipe axial direction (C in the drawing) is larger than the sum of the lengths of the small-diameter portion 18 and the slope portion 16 (E in the drawing) and larger than the length of the large-diameter portion 14 (D-E in the drawing). Thus, when the ring member 6 is disposed on the ring member mounting position 12, there is a clearance 28 between the ring member 6 and at least one of the locking walls 8. For this reason, the ring member 6 can slide in the pipe axial direction over the ring member mounting position 12.

[0111] As above, the reduced diameter portion 22, which is a side end part of the ring member 6, is attached to be positioned on the large-diameter portion 14, and the reduced diameter portion 22 moves and slides over the large-diameter portion 14. However, since size of the ring member 6 is larger than the sum of the lengths of the small-diameter portion 18 and the slope portion 16, the ring member 6 as a whole never falls into the small-diameter portion 18 or the slope portion 16.

[0112] Instead of the ring member 6, a ring member 6a shown in FIG. 18 may be used. The ring member 6a has almost the same structure as the ring member 6 except that slide guides 61 are formed therein. The slide guides 61 are formed, from the reduced diameter portion 22 toward the other end part, at parts of the ring member 6a where the click portions 24 are not provided.

[0113] Unlike the click portion 24, in which the diameter thereof increases from the reduced diameter portion 22 toward the other end part, the slide guide 61 is formed substantially parallel to an axial direction of the ring member 6a. Thus, when the ring member 6a is mounted on the male fitting portion 4 of the pipe joint 1 as shown in FIG. 16, the slide guide 61 protrudes parallel to the pipe axial direction from the reduced diameter portion 22.

[0114] In this case, the region between the locking walls 8 is formed in a straight pipe shape and the ring member mounting position 12 is a substantially cylindrical-shaped periphery face between the locking walls 8. The slide guide 61 protrudes parallel to the pipe axial direction from the reduced diameter portion 22 toward the other end. Thus, when the ring member 6a is mounted on the male fitting portion 4, the slide guide 61 protrudes parallel to the pipe axial direction from the reduced diameter portion 22 on the straight-pipe-shaped ring member mounting position 12. Thus, the slide guide 61 and the locking wall 8 restrict the movement of the ring member 6a.

[0115] A ring member 6b shown in FIG. 19 may also be used. The ring member 6b is a substantially C shaped member having end portions in periphery direction 65 on each of which a ring member connecting portion 63 is formed. The both end portions in periphery direction 65 are overlapped and joined with each other.

[0116] The first ring member connecting portion 63 of the ring member 6b has an adhesive layer with release paper formed directing outward of a center direction, and the second ring member connecting portion 63 has an adhesive layer with release paper formed directing inward of the center direction. Releasing the release paper of each of the end portions in periphery direction 65 enables the ring member connecting portions 63 to face each other and to be bonded, forming the ring member 6b into a ring shape. By providing the ring member connecting portions 63 in the ring member 6b, connecting the end portions in the circumference direction with the others, and forming a ring in this way, the ring member 6b can slide and move stably gripping the large-diameter portion 14 without inclining to the large-diameter portion 14 when the ring member 6a slides and moves over the large-diameter portion 14 of the male fitting portion 4.

[0117] Also, a ring member 6c shown in FIG. 20 (a) may be used. The ring member 6c is a substantially C shaped member having the end portions in periphery direction on each of which the ring member connecting portion 63 is formed so the both end portions in periphery direction 65 are overlapped and joined with each other. As shown in FIG. 20 (b), gear teeth are formed on facing surfaces of the ring member connection portions 63 on both ends in the circumference direction, and engaging the gear teeth with each other can connect the ends in the circumference direction of the ring member 6c with each other.

[0118] At this time, by adjusting a position where the gear teeth on the facing surfaces of the ring member connecting portions 63 engage with each other, an opening diameter of the reduced diameter portion of the ring member 6c can be adjusted to fit a size of the outer periphery of the ring member mounting position 12. By providing the slide guides 61 in the ring member 6c and connecting the end portions in the circumference direction using the ring member connecting portions 63 in this way, the ring member 6c can slide and move stably gripping the ring member mounting position 12 without inclining to the ring member mounting position 12 when the ring member 6c slides and moves over the ring member mounting position 12 of the male fitting portion 4.

[0119] Next, a method for connecting the male fitting portion 4 of the pipe joint lb and a female fitting portion 43 will be described. FIG. 21 is a view showing a state in which the male fitting portion 4 and the female fitting portion 43 are disposed facing each other and the male fitting portion 4 is inserted into the female fitting portion 43. In the illustrations, an example using the ring member 6 will be described. First, as shown in FIG. 21, a tip end of the male fitting portion 4 is inserted into the female fitting portion 43.

[0120] The female fitting portion 43 is formed on an inner periphery part of the tip end (an opening part) of the pipe body 49. The female fitting portion 43 includes, from the tip end side, in sequence, a female-side tubular portion 35, a female-side slope portion 37 whose diameter gradually decreases from the female-side tubular portion 35, and a ring fitting portion 39 whose diameter increases from a minimum inner diameter part of the female-side slope portion 37.

[0121] As show in FIG. 22 (a), when the male fitting portion 4 is pushed into the female fitting portion 43 from this state (an arrow F in the drawing), a tapered portion on the outer periphery of the ring member 6 disposed on the ring member mounting position 12 contacts the female-side slope portion 37 of the female fitting portion 43. When the male fitting portion 4 is further pushed inside the female fitting portion 43, as shown in FIG. 22 (b), vicinity of the reduced diameter portion 22 of the ring member 6 can slide and move from the large-diameter portion 14 to vicinity of the slope portion 16 of the male fitting portion 4 (an arrow G in the drawing).

[0122] Here, the ring member 6 can slide and move within the ring member mounting position 12 until the tip ends of the click portions 24 are in contact with the locking wall 8. At this time, the length of the ring member 6 is larger than the length of the small-diameter portion 18, and thus an end portion on the side of the reduced diameter portion 22 of the ring member 6 lies on the large-diameter portion 14.

[0123] When the male fitting portion 4 is pushed into the female fitting portion 43 from this state, the click portion 24 of the ring member 6 rotates as if falling toward the pipe axial direction with a contacting part between the slope portion 16 of the male fitting portion 4 and the large-diameter portion 14 of the ring portion 6 as a supporting point, and this can elastically deform the ring member 6 and reduce the diameter thereof. That is, the click portion 24 of the ring member 6 rotates as if falling toward the pipe axial direction with a contacting part between the inner periphery side of the reduced diameter portion 22 of the ring member 6 and the large-diameter portion 14 of the male fitting portion 4 as a supporting point. Thus, a part of vicinity of the tip end of the click portion 24 can be accommodated inside the small-diameter portion 18 of the male fitting portion 4.

[0124] As shown in FIG. 23 (a), when the male fitting portion 4 is further pushed into the female fitting portion 43 from this state (an arrow F in the drawing), the end part of the click portion 24 passes beyond the female-side slope portion 37 of the female fitting portion 43. At this time, the click portion 24 that has been elastically deformed is now released from a pressure from the slope portion 37 and restores into an original diameter and expands (an arrow J in the drawing). This makes the click portion 24 to be accommodated into the ring fitting portion 39 that is formed on the base side of the female-side slope portion 37 of the female fitting portion 43.

[0125] FIG. 23 (b) is a view showing a connection structure 10 for the male fitting portion 4 connected with the female fitting portion 43, which can be obtained in this way. In this state, the tip end of the click portion 24 fits into the ring fitting portion 39 of the female fitting portion 43. Thus, if the female fitting portion 43 is pulled out (an arrow K in the drawing), the locking wall 8 restricts movement of the ring member 6 and it is impossible to pull out the male fitting portion 4 from the female fitting portion 43.

[0126] In FIG. 23, the water sealing member 32 is disposed on the water sealing member holder between the locking walls 8. In this state, the outer periphery surface of the water sealing member 32 is in close contact with an inner face of the female-side tubular portion 35 of the female fitting portion 43. That is, the water sealing member 32 can fill a space between the male fitting portion 4 and the female fitting portion 43. This can stop water entering into the connection structure 10.

[0127] Also, since the water sealing member 32 is disposed farther on the base side than the ring member 6, when the male fitting portion 4 is pushed into the female fitting portion 43, the male fitting portion 4 does not receive resistance from the water sealing member 32 until the female fitting portion 43 comes into contact with the water sealing member 32. Thus, a thrusting resistance of the male fitting portion 4 to the female fitting portion 43 can be reduced.

[0128] FIG. 24 is a view showing another embodiment of the connection structure 10, which is a connection structure for the male fitting portion 4 using the ring member 6a (see FIG. 18) and the female fitting portion 43. As mentioned above, the ring member 6a includes the click portion 24 and the slide guide 61. Also in this case, when the male fitting portion 4 is pushed into the female fitting portion 43, the click portion 24 comes into contact with the female-side slope portion 37 of the female fitting portion 43. Pushing the male fitting portion 4 further into the female fitting portion 43 can make the tip end of the slide guide 61 of the ring member 6a slide and move until the slide guide 61 comes into contact with the locking wall 8 on the base side of the male fitting portion 4.

[0129] When the male fitting portion 4 is further pushed into the female fitting portion 43 from this state, the click portion 24 deforms and passes beyond the female-side slope portion 37 of the female fitting portion 43, and then the elastically deformed click portion 24 is released from the pressure from the female-side slope portion 37 and restores into the original diameter and expands. This makes the tip end of the click portion 24 to fit into the ring fitting portion 39 of the female fitting portion 43. Thus, if the female fitting portion 43 is pulled out (an arrow M in the drawing), the locking wall 8 restricts the movement of the ring member 6a and the male fitting portion 4 is never pulled out of the female fitting portion 43.

[0130] FIG. 25 is a view showing another embodiment of the connection structure 10, which is a connection structure for the male fitting portion 4 using the ring member 6c (see FIG. 20) and the female fitting portion 43. As mentioned above, the ring member 6c includes the click portion 24 and the slide guide 61, and, in addition, the ring member connecting portions 63 are formed on the end portions thereof in the circumference direction. In this case, after the ring member 6c is disposed on the ring member mounting position 12 of the male fitting portion 4, the ring member connecting portions 63 are joined with each other to make the ring member 6c into a ring.

[0131] Also in this case, similarly as shown in FIG. 24, the slide guide 61 restricts sliding of the ring member 6c and since the ring member 6c is in a ring shape, the ring member 6c does not incline within the ring member mounting position 12 nor comes off. Also in this case, if the female fitting portion 43 is pulled out (the arrow M in the drawing), the locking wall 8 restricts the movement of the ring member 6c and the male fitting portion 4 is never pulled out of the female fitting portion 43. In FIG. 24 and FIG. 25, the water sealing member 32 is disposed in the same way as in FIG. 23.

[0132] According to the third embodiment, the same effects as in the first embodiment can be obtained. That is, one end of the pipe joint lb can be connected with the rectangular electric wire pipe 40 that is cut at the pipe-body small-diameter portions 45, in which the rectangular electric wire pipe 40 includes the alternately formed pipe-body large-diameter portions 44, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions 45, which are circular shaped valley parts. Also, the male fitting portion 4 on the other end of the pipe joint lb can be connected with the female fitting portion 43, which is formed on the inner periphery part of the pipe body 49 and includes, from the tip end, the female-side tubular portion 35, the female-side slope portion 37 whose diameter gradually decreases from the female-side tubular portion 35, and the ring fitting portion 39 whose diameter increases from the minimum inner diameter part of the female-side slope portion 37.

[0133]

Also, since the ring member 6 or the like is disposed on the outer face of the male fitting portion 4, the ring member 6 or the like can be easily visually recognized at the connection part between the rectangular electric wire pipe 40 and the female fitting portion 43.

[0134] Also, when the male fitting portion 4 is inserted into the female fitting portion 43, the ring member 6 or the like can be efficiently deformed owing to both effects of a diameter expansion due to an increase in a periphery length of the ring member by an elastic repulsive force of the ring member 6 or the like and a diameter expansion of the click portion 24 in a cross section taken in the pipe axial direction due to a restoration of bending transformation. Thus, if a thickness of the click portion 24 of the ring member 6 or the like to which a pulling out force is applied is increased, the diameter of the ring member 6 can still be easily reduced. As a result, connecting the male fitting portion 4 with the female fitting portion 43 is easy and it is possible to prevent the male fitting portion 4 from being pulled out from the connected status with certainty.

[0135] Also, the ring member 6 or the like can slide and move within the ring member mounting position 12. Thus, when the male fitting portion 4 is pushed inside the female fitting portion 43 in a case of using the ring member 6 or 6b for example, vicinity of the end part of the ring member 6 or 6b can be positioned in vicinity of a border part between the large-diameter portion 14 and the slope portion 16. Thus, at the time of connection, the ring member 6 or 6b can be deformed easily with the vicinity of the contacting point of the vicinity of the border part between the large-diameter portion 14 and the slope portion 16 with the ring member 6 or 6b as the supporting point. Also, when a force is applied in a direction in which the male fitting portion 4 is pulled out, the ring member 6 or 6b moves to be positioned on the outer periphery part of the large-diameter portion 14 of the ring member 6. This can prevent a decrease in diameter of the ring member 6 or 6b.

[0136] In particular, since the ring member 6 or the like is in a sharp wedge shape, in which the thickness thereof decreases from the tip end of the click portion 24 toward the reduced diameter portion 22, when the diameter of the ring member 6 or the like is reduced, the ring member 6 or the like can be easily deformed with the contacting part with the slope portion 16 within the ring member mounting position 12 as the supporting point.

[0137] Also, if the ring member 6a or 6c is used, the ring member 6a or 6c includes the slide guide 61 formed and thus the ring member 6a or 6c can slide and move stably without inclining.

[0138] In particular, if the ring member 6c is used, the ring member 6c includes the ring member connecting portions 63 formed, and, for example, adjusting fitting position of the gear teeth formed on the facing surfaces of each of the ring member connecting portions 63 can adjust the size of the diameter of an opening of the reduced diameter portion of the ring member. Thus, even when connecting the rectangular electric wire pipe 40 having a large opening diameter, which tends to have a large size variation in manufacturing, to the pipe joint 1, the ring member 6c can slide and move stably.

[0139] Although the embodiments of the present invention have been described referring to the attached drawings, the technical scope of the present invention is not limited to the embodiments described above. It is obvious that persons skilled in the art can think out various examples of changes or modifications within the scope of the technical idea disclosed in the claims, and it will be understood that they naturally belong to the technical scope of the present invention. Also, the present invention includes combinations of the embodiments disclosed in the descriptions of the embodiments of the present invention.

DESCRIPTION OF NOTATIONS

[0140] 1, la, lb .......... pipe joint 2 .......... small-diameter-portion fixing portion 3, 3a, 3b .......... joint body 4 .......... male fitting portion .......... fl-shaped fixing member 6, 6a, 6b, 6c .......... ring member 7 .......... top surface portion 8 .......... locking wall 9 .......... leg portion 10, 10a, 60 .......... connection structure 11 .......... step portion

12 .......... ring member mounting position 13 .......... cylindrical portion 14 .......... large-diameter portion .......... tubular portion 16 .......... slope portion 17 .......... cutout portion 18 .......... small-diameter portion 19 .......... side face 21 .......... top face 22 .......... reduced diameter portion 23 .......... opening portion 24 .......... click portion .......... engaging step portion 26 .......... water sealing member holder 27 .......... engaging portion 28 .......... clearance 29 .......... bottom portion 31, 32 .......... water sealing member 33 .......... tapered portion 34 .......... connection wall .......... female-side tubular portion 37 .......... female-side slope portion 38 .......... slit 39 .......... ring fitting portion .......... rectangular electric wire pipe 43 .......... female fitting portion 44 .......... pipe-body large-diameter portion .......... pipe-body small-diameter portion 49 .......... pipe body 61 .......... slide guide 63 .......... ring member connecting portion .......... end portion in periphery direction

Claims

1. A pipe joint that connects with a pipe-body small-diameter portion of a rectangular electric wire pipe, the rectangular electric wire pipe including a plurality of pipe-body large diameter portions, which are substantially rectangular shaped mountain parts, and pipe-body small-diameter portions, which are circular shaped valley parts, the pipe-body large-diameter portions and the pipe-body small-diameter portions being formed alternately on an outer periphery surface of a pipe body between a male fitting portion and a female portion that are formed on end parts of the pipe body, at least one side of the rectangular electric wire pipe being cut at the pipe-body small-diameter portion, the pipe joint comprising: a joint body; and a I-shaped fixing member, wherein the I-shaped fixing member includes a top surface portion and a pair of leg portions, the leg portions being connected to both end portions of the top surface portion projecting downward at substantially right angles to the top surface portion, and a step portion protruding outward from a connecting portion between the leg portions and the top surface portion is formed below the top surface portion on each side; a small-diameter-portion fixing portion for fixing the pipe-body small-diameter portion is formed on at least one side of the joint body; the small-diameter-portion fixing portion includes a tubular portion, into which the pipe body large-diameter portion is to be inserted, and a cylindrical portion, which is disposed on a farther deep side of the tubular portion, the pipe-body large-diameter portions being disposed on each side of the pipe-body small-diameter portion interposing the pipe-body small-diameter portion; a cutout portion is formed at a part of the tubular portion, the cutout portion opening up an upper part of a substantially rectangular shaped side face and a top face of the tubular portion; and at the time of inserting theI-shaped fixing member from above into the cutout portion, the step portion of the I-shaped fixing member is mounted on an upper portion of a side face of the tubular portion being cut out, and the leg portions of theI-shaped fixing member are inserted into opening portions provided on both sides of a bottom portion of the tubular portion of the joint body to fix theI-shaped fixing member to the joint body.

2. The pipe joint according to claim 1, wherein an engaging step portion is formed inside a side face of the tubular portion at a position corresponding to the cutout portion of the joint body.

3. The pipe joint according to claim 2, wherein an engaging portion directing outward of the leg portion is formed at a predetermined position below the step portion of the I-shaped fixing member, and the engaging step portion and the engaging portion engage with each other vertically.

4. The pipe joint according to any one of claims I to 3, wherein an internal periphery surface of the top surface portion of the II -shaped fixing member is either in a substantially arc shape or an arch shape.

5. The pipe joint according to any one of claims I to 4, wherein an opening portion is formed on each side of a bottom portion of the tubular portion of the joint body, and the leg portions of the I-shaped fixing member are inserted into the opening portions not to protrude to an outer face of the bottom portion.

6. The pipe joint according to any one of claims I to 5, wherein a water sealing member is disposed on a farther deep side of the cutout portion in the tubular portion of the joint body so as to surround an entire periphery of an inner periphery surface of the tubular portion.

7. The pipe joint according to any one of claims I to 6, wherein the small-diameter-portion fixing portions for fixing the pipe-body small-diameter portion and the cylindrical portions are formed facing each other on both sides of the joint body; and the I-shaped fixing member is inserted into the cutout portion of each of the tubular portions to be fixed to the joint body.

8. The pipe joint according to any one of claims I to 6, wherein one side of the joint body has the small-diameter-portion fixing portion for fixing the pipe body small-diameter portion and the cylindrical portion, and a male fitting portion that is to be fixed to a female fitting portion is formed on the other side of the joint body.

9. The pipe joint according to claim 8, wherein the male fitting portion comprises a pair of locking walls being disposed separately in a pipe axial direction and a ring member being disposed in a region between the locking walls; the ring member is substantially C-shaped with a part in a circumference direction being cut; the ring member includes a reduced diameter portion at one end part thereof and a plurality of click portions being provided side by side separately with slits therebetween to the reduced diameter part in a circumference direction of the ring member, and an outer diameter of the click portion gradually increases from the reduced diameter portion toward a tip end thereof; the ring member is disposed so a tip end of the click portion is positioned on a deeper side of the pipe body and the reduced diameter portion is positioned on a tip end side of the pipe body; a large-diameter portion is formed on the tip end side of the pipe body in the region between the locking walls, a small-diameter portion is formed on the base side of the pipe body in the region between the locking walls, and a slope portion is formed between the large diameter portion and the small-diameter portion; and there is a clearance between the ring member and at least one of the locking walls and the ring member can slide in an axial direction within the region between the locking walls.

10. The pipe joint according to claim 8, wherein the male fitting portion comprises a pair of locking walls being disposed separately in the pipe axial direction and a ring member being disposed in a region between the locking walls; the ring member is substantially C-shaped with a part in a circumference direction being cut; the ring member includes a reduced diameter portion at one end part thereof, a plurality of click portions being provided side by side separately with slits therebetween to the reduced diameter part in a circumference direction of the ring member, and a slide guide being formed protruding parallel to the pipe axial direction from the reduced diameter portion at a part of circumference periphery of the reduced diameter portion where the click portions are not provided, an outer diameter of the click portion gradually increasing from the reduced diameter portion toward a tip end thereof; the ring member is disposed so a tip end of the click portion is positioned on a deeper side of the pipe body and the reduced diameter portion is positioned on a tip end side of the pipe body; the region between the locking walls is formed in a straight pipe shape; and there is a clearance between the ring member and at least one of the locking walls, the ring member can slide in an axial direction within the region between the locking walls, and the slide guide and the locking walls restrict movement of the ring member.

11. The pipe joint according to either claim 9 or 10, wherein a first connecting portion and a second connecting portion are formed on both end portions in a circumference direction of the reduced diameter portion, and the connecting portions are connected with each other to form the ring member into a ring shape.

12. The pipe joint according to claim 6, wherein the water sealing member is either a water expansion non-woven cloth or rubber packing, the water expansion non-woven cloth including polyester fiber, sodium polyacrylate fiber, and binder resin.

13. The pipe joint according to any one of claims I to 12, wherein each of the joint body and theI-shaped fixing member is preferably made from any one of high density polyethylene, polypropylene, ABS resin, PC resin, or polymer alloy of ABS resin or PC resin.

14. A connection structure for rectangular electric wire pipes and a pipe joint, wherein a rectangular electric wire pipe being cut at the pipe-body small-diameter portion is connected to each end portion of the pipe body according to claim 7, the rectangular electric wire pipe including a plurality of the pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions, which are circular shaped valley parts, the pipe-body large-diameter portions and the pipe-body small diameter portions being formed alternately on an outer periphery surface of the pipe body.

15. A connection structure for rectangular electric wire pipes and a pipe joint, wherein one end portion of the pipe joint according to claim 9 is connected with an rectangular electric wire pipe being cut at the pipe-body small-diameter portion, the rectangular electric wire pipe including a plurality of the pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions, which are circular shaped valley parts, the pipe-body large-diameter portions and the pipe-body small diameter portions being formed alternately on an outer periphery surface of the pipe body; and the male fitting portion on the other end portion of the pipe joint is connected with the female fitting portion formed on an inner periphery part of the pipe body, the female fitting portion including, from the tip end side, in sequence, a female-side tubular portion, a female side slope portion whose diameter gradually decreases from the female-side tubular portion, and a ring fitting portion whose diameter increases from a minimum inner diameter part of the female-side slope portion.

16. A connection structure for rectangular electric wire pipes and a pipe joint, wherein one end portion of the pipe joint according to claim 10 is connected with an rectangular electric wire pipe being cut at the pipe-body small-diameter portion, the rectangular electric wire pipe including a plurality of the pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions, which are circular shaped valley parts, the pipe-body large-diameter portions and the pipe-body small diameter portions being formed alternately on an outer periphery surface of the pipe body; and the male fitting portion on the other end portion of the pipe joint is connected with the female fitting portion formed on an inner periphery part of the pipe body, the female fitting portion including, from the tip end side, in sequence, a female-side tubular portion, a female side slope portion whose diameter gradually decreases from the female-side tubular portion, and a ring fitting portion whose diameter increases from a minimum inner diameter part of the female-side slope portion.

17. A connection structure for rectangular electric wire pipes and a pipe joint, wherein one end portion of the pipe joint according to claim 11 is connected with an rectangular electric wire pipe being cut at the pipe-body small-diameter portion, the rectangular electric wire pipe including a plurality of the pipe-body large-diameter portions, which are substantially rectangular shaped mountain parts, and the pipe-body small-diameter portions, which are circular shaped valley parts, the pipe-body large-diameter portions and the pipe-body small diameter portions being formed alternately on an outer periphery surface of the pipe body; and the male fitting portion on the other end portion of the pipe joint is connected with the female fitting portion formed on an inner periphery part of the pipe body, the female fitting portion including, from the tip end side, in sequence, a female-side tubular portion, a female- side slope portion whose diameter gradually decreases from the female-side tubular portion, and a ring fitting portion whose diameter increases from a minimum inner diameter part of the female-side slope portion.

18. The pipe joint according to claim 5, wherein the leg portions of the I-shaped fixing member do not protrude to an outer face of the bottom portion when the leg portions are inserted into the opening portions of the joint body.

Furukawa Electric Co., Ltd. Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON