JP2008029176A - Corrugated synthetic-resin pipe and its pipe-joint structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a corrugated synthetic-resin pipe allowing reliable filling of earth and sand, while resolving the problem of decrease in pressure resistance. <P>SOLUTION: In the corrugated synthetic-resin pipe, when viewed from the direction orthogonal to the axis of the pipe, a number of round-wave parts and square-wave parts are formed on the pipe wall in the axial direction of the pipe.The profile of each of the square-wave parts 2 is formed in a square circumscribing to a circumscribed circle of the round wave part when viewed from the axial direction of the pipe, and at the same time each corner part 5 of the square is rounded arcuately along the circumscribed circle in the vicinity of the outside of the circumscribed circle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a corrugated synthetic resin pipe suitable as a power and communication cable protection pipe, which is buried in the ground or disposed in a building on the ground, and a pipe joint structure thereof.

  Conventionally, a synthetic resin pipe whose pipe wall is formed in a corrugated shape in the pipe axis direction is widely known. For example, a pipe embedded in the ground is used as a cable protection pipe or a drain pipe.

  When a plurality of synthetic resin pipes of this type are arranged in a bundle in the ground, it becomes difficult to maintain a parallel pipe arrangement because earth and sand enter excessively between the pipes. As a result, the round wave synthetic resin pipe in which the bending has occurred decreases the workability when a cable is inserted through it, and the pipe resistance increases when a fluid is passed.

  Therefore, as shown in FIG. 23, a square-wave-like composition in which square tube portions 50 formed in a substantially square shape when viewed from the tube axis direction and cylindrical portions 51 formed in a substantially circular shape are alternately arranged in the tube axis direction. Resin pipes have been proposed.

  In the above synthetic resin pipe, the square tube portions 50 are formed intermittently in the tube axis direction, and the upper and lower surfaces of each square tube portion 50 are constituted by flat surfaces 53, so that stability is ensured when embedded in the ground. In addition, since the earth and sand enter only the cylindrical portion 51, there is an advantage that it is difficult to cause a positional shift even after being buried, and the straightness of the piping can be maintained (for example, see Patent Document 1).

  On the other hand, in the above-described square wave-shaped synthetic resin pipe, as shown in the cross-sectional view of FIG. 24, the thickness of the cylindrical portion 54 is forcibly extended so as to become the rectangular tube portion 50. There exists a problem that each corner | angular part 50a-50d of the part 50 will become extremely thin. The thin wall portion has a lower pressure resistance than other portions, and may be damaged when a large earth pressure is applied.

  In addition, when a large number of the rectangular tube portions 50 are provided in succession, it becomes difficult for soil and sand to enter the gap between the tubes as compared with the round wave synthetic resin tube described above. If the synthetic resin pipe is backfilled in such a state that the earth and sand are not sufficiently filled and the cavity is left between the pipes, the earth and sand will flow into the cavity due to the rain or the rise of the groundwater level. This also causes the ground above the synthetic resin tube to sink.

  Furthermore, when connecting this kind of square-wave synthetic resin pipes, since the square tube part 50 protrudes greatly from the cylindrical part 51, naturally the pipe joint must cover the protruded square tube part 50. The structure of the pipe joint increases. This enlarged pipe joint becomes an obstacle when the synthetic resin pipes are arranged close to each other.

Therefore, the inventor of the present invention can reliably fill the earth and sand while eliminating the decrease in the pressure strength in order to solve the above-described problems in the conventional uneven corrugated waveform or square wave synthetic resin tube. An invention relating to a corrugated synthetic resin pipe is disclosed (for example, see Patent Document 2).
JP 2002-361722 A Japanese Patent Application No. 2005-112678

  By the way, the corrugated synthetic resin tube according to the invention disclosed by the present inventor may be required to have more severe heat resistance and earthquake resistance so that it can sufficiently withstand the use as a protective tube of a power cable.

  The present invention has been made in consideration of the above-mentioned problems, and the object of the present invention is not only to surely fill earth and sand while eliminating the decrease in pressure strength, but also to protect power cables. The object is to provide a corrugated synthetic resin pipe having sufficient heat resistance and earthquake resistance for use as a pipe.

  The corrugated synthetic resin tube of the present invention is a corrugated synthetic resin tube in which a large number of round wave portions and angular wave portions are formed in the tube axis direction on the tube wall when viewed from a direction orthogonal to the tube axis direction, The contour of the wave portion is formed in a rectangle circumscribing the outer circumference circle of the round wave portion when viewed from the tube axis direction, and each corner portion of the square is a circle along the outer circumference circle near the outside of the outer circumference circle. The gist of the invention is that the corrugated synthetic resin tube is rounded in an arc shape and is made of a modified polyphenylene ether.

  According to the corrugated synthetic resin pipe of the present invention, the angular wave portion has a square shape when viewed from the tube axis direction, and flat surfaces are formed on the upper and lower sides thereof, so that stability is enhanced when buried in the ground. When stacked on the ground, the sitting stability can be increased to increase the stacking stability.

  In addition, since each corner of the angular wave portion is greatly rounded in an arc shape, it is not necessary to forcibly extend the thickness of the cylindrical portion to the corner during molding, thereby reducing the thickness of the corner. Can be resolved. Moreover, because the corners are rounded in an arc shape, the fluidity of the earth and sand is enhanced, and the sand wave fluidity close to the round wave part can be ensured for the square wave part as well, so that the cavity above the corrugated synthetic resin tube Can be eliminated.

  Furthermore, since the corrugated synthetic resin tube of the present invention is made of modified polyphenylene ether, the heat resistance and the earthquake resistance of the corrugated synthetic resin tube are remarkably enhanced, so that it can be suitably used as a protective tube for power cables. .

  In the corrugated synthetic resin pipe of the present invention, if the corrugated synthetic resin pipe is constituted by repeatedly forming the basic pattern in the tube axis direction with two angular wave portions and one round wave portion continuous therewith as a basic pattern. Even when the laminated corrugated synthetic resin pipes are shifted from each other in the tube axis direction, the flat surfaces of the angular wave portions in both corrugated synthetic resin pipes always come into contact with each other, and can be prevented from falling off.

  In the corrugated synthetic resin pipe of the present invention, a male side joint portion can be provided at one end of the corrugated synthetic resin pipe, and a female side joint portion can be provided at the other end.

  In the corrugated synthetic resin pipe of the present invention, as the male side joint portion, an insertion portion extending from the end portion of the corrugated synthetic resin tube, and at the distal end of the insertion portion are arranged at equal intervals on the circumference thereof. And a receiving part that houses the insertion part as the female-side joint part, and a locking protrusion provided in the receiving part to lock the insertion part. And a retaining means.

  In the corrugated synthetic resin pipe of the present invention, as the retaining means, an annular groove formed in the receiving portion, a ring-shaped support attached to the annular groove, and a direction opposite to the insertion direction from the ring-shaped support. And a plurality of locking pieces extending in a state of converging toward the direction, and these locking pieces are elastic in a direction in which the locking projections are pressed to expand the tip when the insertion port is inserted. It can be configured to be deformed to return to the converged state by passing through the locking projection and to lock the rear portion of the locking projection.

  In the corrugated synthetic resin pipe of the present invention, if a slit is formed in at least one of the ring-shaped support and the locking piece in the tube axis direction, either the ring-shaped support or the locking piece or both Flexibility can be imparted, and mounting on the receiving port is simplified.

  In the corrugated synthetic resin pipe of the present invention, the male side joint portion includes an insertion port extending from the end of the corrugated synthetic resin tube, and the female side joint portion stores the insertion port. And a taper on the outer peripheral surface of the insertion portion and the inner peripheral surface of the reception portion so that the outer peripheral surface of the insertion portion is in close contact with the inner peripheral surface of the reception portion. A surface can be formed.

  A groove for mounting the ring-shaped sealing material can be formed at the base end of the insertion portion.

  The pipe joint structure of the present invention is a pipe joint structure in which a pair of joint parts divided into two are attached to and fixed to a connecting portion of corrugated synthetic resin pipes having the above-described configuration, and the joint part is An arch that can be fitted into a trough between the round wave portion and the angular wave portion in the corrugated synthetic resin tube, and a trough between the round wave portion and the angular wave portion in the other corrugated synthetic resin tube An arch portion, an arch portion that is in contact with the butted portions of the two corrugated synthetic resin pipes, and a connecting portion that connects the hem side end of each arch portion in the tube axis direction, and the joint portion divided in two It is configured so that when connected to a corrugated synthetic resin tube to be integrated, the connecting portions face each other and can be fastened and fixed by fastening means, and the connecting portions are generated by being rounded in an arc shape at the corner of the angular wave portion. To fit in the corner space Made is the gist that are.

  According to the pipe joint structure of the present invention, when a split joint portion is attached to the connected portion of the corrugated synthetic resin pipe, the arch portion fits into the valley portion between the round wave portion and the square wave portion. The connecting part that fixes the corrugated synthetic resin pipe and connects the arch part fits in the corner space between the square corner (virtual) of the corrugated synthetic resin pipe and the rounded arc, so it is larger than the angular wave part. The corrugated synthetic resin tube can be connected in a compact manner without protruding.

  In the pipe joint structure of the present invention, a sealing material can be attached to the inside of the arch part attached to the connection portion of the corrugated synthetic resin pipe.

  According to the corrugated synthetic resin pipe of the present invention, since the corner portion of the angular wave portion is rounded in an arc shape when viewed from the tube axis direction, the thinning is eliminated by not performing excessive stretching at the time of molding. A decrease in strength is prevented. Moreover, since the corners are rounded in an arc shape, the fluidity of the earth and sand at the time of backfilling is improved, and the generation of cavities in the vicinity of the corrugated synthetic resin pipe laid can be prevented.

  Moreover, since the round wave part is interposed between the angular wave parts in the tube axis direction, flexibility can be provided while increasing the compressive strength.

  Moreover, since the corrugated synthetic resin pipe of the present invention is composed of modified polyphenylene oxide, it can exhibit excellent heat resistance and earthquake resistance.

  According to the pipe joint structure of the present invention, the joint structure for connecting the corrugated synthetic resin pipe having the angular wave portion and the round wave portion can be made compact.

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

  FIG. 1 shows a configuration of a corrugated synthetic resin pipe according to the present invention. A corrugated synthetic resin pipe (hereinafter abbreviated as a corrugated pipe) 1 has a long basic pattern consisting of two angular wave portions 2 and a single continuous round wave portion 3 in the tube axis direction. It forms a tube (for example, 4 to 300 m depending on the diameter), and FIG. 1 shows a part thereof (a state in which two basic patterns are continuous).

  First, the resin raw material constituting the corrugated tube according to the present invention will be described. To add excellent heat resistance and earthquake resistance that can also be used as a protective tube for power cables to the corrugated tube according to the present invention. The selection of the resin used to construct the corrugated tube is important. Here, the present inventor has found that it is particularly effective to construct the corrugated tube from modified polyphenylene oxide.

  As modified polyphenylene oxide, 2,6-xylenol synthesized from methanol and phenol is oxidatively polymerized to form polyphenylene oxide, which is further converted into polystyrene (PS), polyamide (PA), polypropylene (PP), polybutylene terephthalate (PBT). ), Mixed resins in which a modifying component such as polyphenylene sulfide (PPS) is mixed, and copolymers such as grafts and blocks obtained by polymerizing styrene monomers on polyphenylene oxide.

  The ratio of the modifying component to be mixed with polyphenylene oxide or the styrene monomer to be polymerized to polyphenylene oxide is 90 to 10% by weight of the modifying component or styrene monomer with respect to 10 to 90% by weight of polyphenylene oxide. preferable.

  The modified polyphenylene oxide is available on the market. For example, the product name Noryl manufactured by GE Plastics, Inc., the product names Remalloy, Iupiace, and BASF Japan manufactured by Mitsubishi Engineering Plastics Co., Ltd. Luranyl etc. are mentioned.

  The corrugated tube 1 is formed by continuous blow molding. Specifically, the corrugated tube 1 is inflated by sending air into a tubular molten resin extruded in a circular cross section, and the inflated resin is pressed against the inner surface of the mold. To form. At that time, a part of the cylindrical molten resin is formed into the angular wave part 2, and another part is formed into the round wave part 3.

  As a result, the inner wall 4 of the corrugated tube 1 has a corrugated shape following the formed angular wave portion 2 and round wave portion 3. However, the present invention does not exclude the multilayered corrugated tube 1 in which the inner tube is inserted into the corrugated tube 1. For example, an inner tube made of flexible rubber, vinyl chloride resin, or the like is inserted to supply fluid. It is also possible to reduce the flow path resistance when flowing or to improve the way when the cable is inserted.

  The method for forming the corrugated tube 1 is not limited to the above-described continuous blow molding, and for example, it can be formed by vacuum molding. In this case, the tube-shaped molten resin extruded into a circular cross section is sucked from the slit-shaped groove provided in the mold and is stuck to the inner surface of the mold.

  Further, each corner 5 in the angular wave portion 2 is formed in a state of being cut off in an arc shape, and thus has a shape close to the round wave portion 3.

  FIG. 2 shows the corrugated tube 1 as viewed from the tube axis direction, and the rectangular surface S of the angular wave portion 2 can be seen in the portion shown by cutting out a portion of the round wave portion 3.

  When it is assumed that the corner of the rectangular surface S is not rounded into an arc, the length L1 of one side coincides with the diameter M of the round wave portion 3. That is, the outer circumferential circle of the round wave portion 3 is inscribed in the rectangular surface S.

  Further, 60% of the length L1 of one side, that is, 0.6L1 is the length of one side of the actual angular wave portion 2.

  When the signs a and b, c and d, e and f, g and h are respectively attached to both ends of the actual length of each side, the corner 5 of the actual rectangular surface S is represented by bc, de, It is formed by an arc connecting f-g and ha. These arcs are constituted by a part of concentric circles having a diameter (diameter N) larger than the diameter M of the round wave portion 3.

  FIG. 3 shows a cross section taken along the line AA in FIG.

  The outer peripheral surface 3a of the round wave portion 3 and the outer peripheral surface 2a of the angular wave portion 2 are aligned at the same height (see S1) so that stability is obtained when the corrugated tubes 1 are laminated. In addition, the inner peripheral surface 3b of the round wave portion 3 is also arranged at the same height (see S2).

  FIG. 4 shows a cross section taken along line BB in FIG.

  In FIG. 4, the protruding portion 2 b that appears higher than the outer peripheral surface 3 a of the round wave portion 3 is a portion that contributes to enhancing the sitting of the corrugated tube 1, and in FIG. 2, the diagonal direction from the round wave portion 3 to the rectangular surface S This corresponds to the projecting portion 2b projecting. Moreover, in the figure, C has shown the protrusion 2b inner surface.

  Also, in the tube axis direction, the distance obtained by adding the lengths of the peaks of the two angular wave portions 2 is L2, and the distance from the next angular wave portion 3 (where the round wave portion 3 is formed) is L3. In this case, the angular wave portion 2 and the round wave portion 3 are formed so that the relationship of L2> L3 is established.

  Accordingly, even if the laminated corrugated tubes 1 are relatively moved in the tube axis direction, the flat surfaces of the angular wave portions 2 always abut against each other in the upper and lower corrugated tubes 1, so that the corrugated tube 1 can be prevented from falling off. It has become.

  When the number of peak portions of the angular wave portion 2 is 2 or more, the number of the round wave portions 3 is reduced, and the effect of the round wave portion 3, that is, flexibility is reduced and piping workability is lowered. When the number of peak portions of the angular wave portion 2 is less than 2, the upper corrugated tube 1 is dropped when the corrugated tube 1 is shifted in the tube axis direction in a stacked state.

  Further, in the corrugated tube 1 having the above-described configuration, as shown in FIG. 1, in order to enhance the sitting of the tube, the shape of the angular wave portion 2 is a square shape (flat surfaces are formed vertically and horizontally as viewed from the tube axis direction). However, since the corner portion is rounded in an arc shape, the fluidity of sand substantially equal to that of the round wave portion 3 can be ensured for the square wave portion 2 as well.

  Moreover, since the round wave portion 3 has a U-shaped bent portion as shown in FIG. 3, the round wave portion 3 is rich in flexibility, and a conventional square wave synthetic resin pipe (tube axis as shown in FIG. 16). The degree of freedom of piping is higher than that of a square tube portion 50 formed in a substantially square shape when viewed from the direction and a square wave synthetic resin tube in which cylindrical portions 51 formed in a substantially circular shape are alternately arranged in the tube axis direction). There is an advantage.

  Next, FIG. 5 shows the configuration of the male joint portion 10 formed at one end of the corrugated tube 1, and FIG. 6 shows the male side joint formed at the other end of the corrugated tube 1. The structure of the female side joint part 20 connected with the part 10 is shown.

  First, the structure of the male side joint part 10 is demonstrated.

  The male side joint portion 10 includes a cylindrical insertion portion 10 a that extends from the round wave portion 3 that is located closest to the end portion of the corrugated tube 1. A large-diameter portion 10b having an enlarged diameter is formed substantially in the middle of the insertion portion 10a, and four locking portions (locking protrusions) 10c are provided at the tip of the insertion portion 10a. It is arranged at equal intervals in the direction. In addition, the latching | locking part 10c is arrange | positioned at the up-and-down left and right of the insertion part 10a outer wall.

  FIG. 7 shows a cross section of the male joint 10 shown in FIG. 5 cut in the D direction.

  In FIG. 7, the large-diameter portion 10 b formed in a convex cross-section has a front inclined surface 10 d that is inclined downward in the connecting direction, and a trailing portion 10 e formed on the rear side.

  Each locking portion 10c is provided in a state of projecting in the diametrical direction from the distal end of the insertion portion 10a, and an inclined surface 10f that is tapered downward toward the connection direction is formed on the front side. Is smooth.

  Further, a falling portion 10g is formed on the rear side of the locking portion 10c, and is engaged with a retaining ring (described later) provided in the female side joint portion 20.

  FIG. 8 shows a cross section of the male joint 10 of FIG. 5 cut in the E direction.

  Between each latching | locking part 10c, the protruding item | line 10h is formed in the circumferential direction, respectively, and gives a moderate resistance when connecting the male side joint part 10 and the female side joint part 20, or isolate | separating It is like that.

  Next, returning to FIG. 6, the configuration of the female joint 20 will be described.

  In the figure, the female side joint part 20 is provided with a cylindrical receiving part 20a extending from the round wave portion 3 located on the most end side of the corrugated tube 1. The receiving portion 20a is formed to have a slightly larger diameter than the insertion portion 10a so that the insertion portion 10a can be inserted.

  The receptacle 20a is provided with a retaining ring mounting portion 20b.

  The retaining ring mounting portion 20b is formed in a state of being raised like a comb tooth (in a state of being recessed when viewed from the inside of the receiving portion 20a).

  FIG. 9 shows the female joint 20 of FIG. 6 cut in the F direction.

  As shown in FIG. 9, the retaining ring mounting portion 20 b is formed with rectangular shallow grooves 20 c at positions corresponding to the locking portions 10 c of the male joint portion 10, and each shallow groove 20 c is circumferential. It communicates with an annular shallow groove (annular groove) 20d formed on the surface. In the drawing, reference numeral 20e denotes a range where the shallow groove 20c and the annular shallow groove 20d are in communication with each other in the retaining ring mounting portion 20b.

  FIG. 10 is a cross section of the female side joint portion 20 of FIG. 6 cut in the G direction, and 20f shows a range where the annular shallow groove 20d is formed in the retaining ring mounting portion 20b.

  11 to 15 show various forms of the retaining ring attached to the retaining ring mounting portion 20b.

  FIG. 11A is a front view showing a first form of the retaining ring 30, and FIG. 11B is a side view thereof.

  In both figures, the retaining ring 30 is made of ABS, polypropylene resin, or the like, and a ring-shaped support 30a that can be fitted into the annular shallow groove 20d, and is extended from the ring-shaped support 30a and fitted into the shallow groove 20c. The ring-shaped support body 30a and the locking piece 30b are integrally formed.

  Each locking piece 30b protrudes slightly inward from the trunk inner wall 20g of the female joint 20 in a state where it is fitted in the shallow groove 20c.

  The annular shallow groove 20d and the retaining ring 30 attached to the annular shallow groove 20d function as retaining means.

  Each locking piece 30b functions as a leaf spring that generates an urging force, and when the male side joint part 10 and the female side joint part 20 are joined, the locking part of the male side joint part 10 is provided. By being pressed by 10c, it is elastically deformed outward (arrow H direction) against the urging force.

  When the joint portions 10 and 20 are further deeply connected and the locking portion 10c passes through the locking piece 30b, the locking piece 30b returns to the original posture shown in FIG. 11 (b) by the urging force. ing.

  As a result, the rising portion 10g (see FIG. 7) of the locking portion 10c is locked by the tip of the returned locking piece 30b, and the male joint portion 10 is fixed to the female joint portion 20. .

  Since the retaining ring 30 includes a ring-shaped support 30a, the dimensional stability after molding and after molding is higher than that of a conventional C-shaped retaining ring, and it is possible to maintain stable performance. There is. In addition, the cost can be reduced by reducing the defect occurrence rate during molding.

  FIG. 12A is a front view showing a second form of the retaining ring, and FIG. 12B is a side view thereof.

  The retaining ring 31 shown in FIG. 12 has the same ring-shaped support 31a as the ring-shaped support 30a, and a plurality of locking pieces 31b are extended from the ring-shaped support 31a.

  Each locking piece 31b is divided by a slit 31c formed in the middle thereof, and the locking piece 31b is elastically pressed with a smaller pressing force than the locking piece 30b of the retaining ring 30 shown in FIG. It can be deformed and the joint connection operation can be performed smoothly.

  FIG. 13A is a front view showing a third form of the retaining ring, and FIG. 13B is a side view thereof.

  The retaining ring 32 shown in FIG. 13 has a ring-shaped support body 32a, and a locking piece 32b extends from the ring-shaped support body 32a. The ring on which the locking piece 32b extends. A slit 32c is formed in the cylindrical support 32a in the tube axis direction.

  The slit 32c extends to a substantially intermediate position in the tube axis direction of the locking piece 32b, and has a function of facilitating the elastic deformation of the locking piece 32b and the deformation of the ring-shaped support 32a.

  Therefore, when the retaining ring 32 is used, the locking piece 31b can be elastically deformed with a smaller pressing force than the retaining ring 30 shown in FIG. Since the degree of freedom of deformation increases, it is easy to attach the retaining ring 32 to the shallow groove 20c.

  FIG. 14A is a front view showing a fourth form of the retaining ring, and FIG. 14B is a side view thereof.

  The retaining ring 33 shown in FIG. 14 has a ring-shaped support 33a, and a pair of locking pieces 33b extend from the ring-shaped support 33a at equal intervals.

  A slit 33c is formed in each of the pair of locking pieces 33b toward the tube axis direction.

  These two slits 33c extend to a substantially intermediate position in the tube axis direction of the locking piece 33b, and the elastic deformation of the locking piece 33b and the deformation of the ring-shaped support 33a are compared with those shown in FIG. It works to make it even easier.

  FIG. 15A is a front view showing a fifth form of the retaining ring, and FIG. 15B is a side view thereof.

  The retaining ring 34 shown in FIG. 15 has a ring-shaped support 34a, and a pair of locking pieces 34b are extended on the ring-shaped support 33a at equal intervals.

  A slit 34c is formed in each of the pair of locking pieces 34b toward the tube axis direction.

  These slits 34c extend to substantially the front end portion of the locking piece 34b, and facilitate the elastic deformation of the locking piece 34b in the same manner as the locking piece 33b shown in FIG.

  In addition to the slit 34c formed in the locking piece 33b for the ring-shaped support 34a, a short slit 34d is also formed for the ring-shaped support 34a between the locking pieces 34b. The body 34a can be deformed into a desired shape. As a result, the retaining ring 34 can be attached more easily.

  FIG. 16 shows a rubber packing ring (ring-shaped sealing material) 35 attached to the annular groove (groove) 10i of the insertion slot 10a shown in FIG.

  The packing ring 35 is formed with a plurality of cross-sectional wedge-shaped projections 35a in the joint connection direction, and the male joint portion 10 can be easily inserted in the connection direction. Acts as a resistance and ensures water-stopping.

  The connection method of the male side joint part 10 and the female side joint part 20 which consist of the said structure is demonstrated.

  The male side joint part 10 and the female side joint part 20 are made to oppose, and the insertion part 10a is inserted in the receiving part 20b. At this time, if the insertion portion 10a is inserted 45 ° clockwise (or counterclockwise) when viewed from the tube axis direction, the locking portion 10c is removed from the receiving portion 20b. Since it passes between the locking pieces 30b of the retaining ring 30, it does not contact them and is inserted into the receiving portion 20b without resistance.

  After the insertion, when the insertion portion 10a is rotated by 45 ° in the opposite direction, the locking portion 10c is engaged with and locked with the locking piece 30b, and the insertion portion 10a is prevented from coming off.

  On the other hand, if the insertion part 10a is inserted into the receiving part 20b as it is without rotating, a certain resistance is applied because the locking part 10c comes into contact with the locking piece 30b. However, since the locking piece 30b is configured to be elastically deformable in the spreading direction, the locking portion 10c can get over the locking piece 30b when inserted against the resistance, and the locking piece 30b. When passing, the locking portion 10c and the locking piece 30b are engaged and locked.

  Thus, according to the structure of the male side joint part 10 and the female side joint part 20 of this invention, even if it is a lamination | stacking state, for example, even if it is a lamination | stacking state, the corrugated pipes 1 are connected with each other without rotating the corrugated pipes 1. There is an advantage that you can. Thereby, the handling of the corrugated tube 1 on site and the connection workability are greatly improved.

  In addition, the structure of the male side joint part 10 formed in the edge part of the corrugated tube 1 concerning this invention and the female side joint part 20 is not limited to said aspect.

  For example, as shown in FIG. 17, the male joint portion 10 includes a cylindrical insertion portion 10 a extending from the angular wave portion 2 located closest to the end portion in the corrugated tube 1. The outer peripheral surface of the insertion portion 10a has a tapered surface that gradually inclines toward the connection direction toward the inner peripheral surface of the insertion portion 10a so that the outer diameter of the insertion portion 10a decreases toward the connection direction. It may be formed.

  Moreover, the female side joint part 20 is provided with the cylindrical receptacle part 20a extended from the angular wave part 2 located in the end part side of the corrugated tube 1, and this receptacle part 20a is the said insertion port. It is formed to be slightly larger in diameter than the insertion portion 10a so that the portion 10a can be inserted, and the inner diameter of the reception portion 20a is increased in diameter toward the connection direction. As described above, a tapered surface that is gradually inclined toward the outer peripheral surface of the receiving portion 20a toward the connection direction may be formed.

  Thereby, the male side joint part 10 and the female side joint part 20 can carry out taper fitting.

  In addition, in order to prevent that the said insertion part 10a is inserted into the said receiving part 20a more than necessary on the internal peripheral surface of the female side joint part 20, the projection part 11 which the front-end | tip of the insertion part 10a contacts is carried out. It may be provided.

  Next, FIG. 18 shows a pipe joint for connecting the corrugated pipes 1 in a portion where the joint part does not exist, such as when the corrugated pipe 1 is cut halfway.

  In the figure, a pipe joint 40 is divided into a first joint part 41 (front side of the drawing) and a second joint part 42 (back side of the drawing) that can be divided into two, and bolts (fastening means) for connecting the joint parts 41, 42. 43.

  The first joint portion 41 includes three arch portions 41a, 41b, and 41c that are curved in a semicircular shape, and three coupling portions 41d, 41e, and 41f that connect these arch portions 41a to 41c in the joint axial direction. It is composed of

  The connecting portion 41d connects one end portions of the arch portions 41a, 41b, 41c, leg portions 41g, 41h, 41i projecting outward from the arch portions 41a-41c, and the leg portions 41g, 41h and 41i are formed of a rod-shaped member 41j having a triangular cross section that communicates the tips of the terminals 41h, 41i, and bolt holes are formed in the leg portions 41g to 41i for inserting the bolts 43, respectively.

  Similarly to the connecting portion 41d, the connecting portion 41f includes three leg portions 41k, 41l, and 41m, and a rod-shaped member 41n having a triangular cross section that connects the tips of the leg portions.

  Moreover, the connection part 41e consists of the rod-shaped member 41o which connects the center part of the arch parts 41a-41c to a joint axial direction.

  In addition, the 2nd coupling part 42 is comprised by the above-mentioned 1st coupling part 41 and object.

  Therefore, when the leg portions 41g to 41i and the leg portions 41k to 41m of the first and second joint portions 41 and 42 are overlapped with each other, the semicircular arch portions 41a, 41b, and 41c are connected to each other to form a ring. It becomes a shape.

  Further, when the rod-shaped members 41j and the rod-shaped members 41n are overlapped, the tip ends thereof have the same mountain shape as the connecting portion 41e. That is, the connecting portions 41 d, 41 e, 41 f, 41 e are fitted to the respective corners of the contour I of the virtual rectangular surface, and the rectangular surface I is the contour I of the rectangular surface of the angular wave portion 2 of the corrugated tube 1. It matches ′.

  As described above, the pipe joint 40 is configured to be attached by using the cutout portion formed by rounding the angular wave portion of the corrugated tube 1 into an arc shape, so that the angular wave portion of the corrugated tube 1 shown in FIG. It can be attached to the corrugated pipe 1 so as to fit in the two rectangular surfaces I ′, and the pipe joint 40 can be made compact.

  When the pipe joint 40 is attached to the connection portion of the corrugated tube 1, the ring-shaped arch portion 41 a is fitted into the valley of the round wave portion 3 of one corrugated tube 1, and the arch portion 41 c is the other corrugated tube 1. It fits into the valley of the round wave portion 3.

  Further, as shown in FIGS. 20 (a) and 20 (b), a ring-shaped rubber packing 44 is disposed as a sealing material inside the arch portion 41b, and the connection portion of the corrugated tube 1 is stopped. ing. The packing 44 has an outer peripheral side formed on a flat surface 44a and an inner peripheral side formed on an arcuate surface 44b.

  As described above, the pipe joint 40 of the present invention is configured to connect the round wave portion of the corrugated tube 1 with an externally-embedded type, and therefore has a water-stopping property compared to the case where the angular wave portion is connected with an externally-mounted type. Can be increased.

  21 shows the first joint portion 41 of the disassembled pipe joint 40 as viewed from the outside, and FIG. 22 shows the second joint portion 42 as viewed from the inside.

  In both figures, the cross sections of the arch portions 41a and 41c swell in a semicircular shape toward the inside and are adapted to fit into the valleys of the round wave portion 3, whereas the cross section of the arch portion 41b Has a flat inside. The packing 44 is disposed on the flat portion.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited at all by these.

(Compressive strength test)
Waveform with the shape shown in Fig. 1 based on the electric wire joint groove pipe material test implementation manual (draft) (supervised by the Kinki Regional Construction Bureau, Ministry of Construction, Issuing Office; Road Conservation Technology Center, issued in January 1999) Whether or not the synthetic resin tube can withstand use as a power cable protection tube or a communication cable protection tube was evaluated by performing a compressive strength test. The specific test method is as follows.

(For power)
After conditioning at a temperature of 75 ° C for 1 hour, the specimen is sandwiched between two flat plates, and after 5 minutes when the testing machine reaches 75 ± 5 ° C, it is compressed at a speed of 10 mm / min in a direction perpendicular to the tube axis. The amount of deflection (flat amount) of the outer diameter of the test specimen when the specified load P is applied is measured.

(For communication)
After conditioning for 1 hour at a temperature of 23 ± 2 ° C, the test specimen is sandwiched between two flat plates, compressed at a speed of 10 mm / min in a direction perpendicular to the tube axis, and tested when a specified load P is applied This is done by measuring the amount of deflection (flattening) of the outer diameter of the body.

(Pass / fail criteria)
If the deflection rate calculated from the deflection amount is 2.5% or less, the test body is accepted as a power cable protection tube or a communication cable protection tube.

(Specified load P)
Here, the specified load P was obtained by the following formula 1.
P = F × L × S (Formula 1)
P: Specified load (kN)
F: Equivalent load (kN / m) that generates a moment equal to the maximum moment when buried
F = 18.1 × R
R: average radius ((outer diameter of specimen + inner diameter of specimen) / 4) (m)
(For the corrugated synthetic resin tube shown in FIG. 1, L1 shown in FIG. 2 is the outer diameter of the test specimen, and L4 shown in FIG. 2 is the inner diameter of the test specimen.)
L: Length of test specimen (m)
S: Safety factor = 3

[Example 1]
1 is a corrugated synthetic resin tube having a shape shown in FIG. 1 using a modified polyphenylene oxide (manufactured by GE Plastics, Inc., trade name: Noryl, grade; NWP100), and has an angular dimension (outer diameter) of 163.16 mm, A specimen having an inner diameter of 132.63 mm and a length of 250 mm was prepared.

  Using the communication test method, the deflection amount (flattening amount) of the outer diameter of the test body when the specified load P calculated from the above equation 1 was applied was measured. The results are shown in Table 1.

[Comparative Example 1]
A test body having the same shape as in Example 1 was prepared except that polyethylene resin was used in place of the modified polyphenylene oxide and the square size (outer diameter) was 161.89 mm, the inner diameter was 131.01 mm, and the length was 250 mm.

  Using the communication test method, the deflection amount (flattening amount) of the outer diameter of the test body when the specified load P calculated from the above equation 1 was applied was measured. The results are shown in Table 1.

  The corrugated synthetic resin tube made of modified polyphenylene oxide is made of polyethylene resin based on the bending ratio based on the difference in resin raw materials (the bending rate of the test body of Example 1 / the bending rate of the test body of Comparative Example 1). Compared to the corrugated synthetic resin pipe, the bending ratio is low, which indicates that it is excellent in compressive strength (seismic resistance).

  In addition, the corrugated synthetic resin pipe made of modified polyphenylene oxide has a linear density that is about 20% lower than that of the corrugated synthetic resin pipe made of polyethylene resin. It was found that the handleability can be improved.

[Example 2]
The amount of deflection (flattening amount) of the outer diameter of the test specimen was measured in the same manner as in Example 1 except that the test method for electric power was used. The results are shown in Table 1.

[Comparative Example 2]
The amount of deflection (flat amount) of the outer diameter of the test specimen was measured in the same manner as in Comparative Example 1 except that the test method for electric power was used. The results are shown in Table 1.

  From a comparison between Example 2 and Comparative Example 2, it was found that the corrugated synthetic resin pipe according to the present invention has a compressive strength (seismic resistance) that can withstand use as a protective pipe for a power cable.

  The corrugated synthetic resin tube composed of the modified polyphenylene oxide according to the present invention is based on the deflection ratio based on the difference in resin raw material (the deflection rate of the test body of Example 2 / the deflection rate of the test body of Comparative Example 2). Compared to the corrugated synthetic resin pipe composed of the above, it was found that the deflection ratio is low at high temperatures and is excellent in earthquake resistance.

  Further, the deflection ratio based on the difference in the test environment (the deflection rate of the test body of Example 2 / the deflection rate of the test body of Example 1 and the deflection rate of the test body of Comparative Example 2 / the test body of Comparative Example 1) The corrugated synthetic resin pipe made of the modified polyphenylene oxide according to the present invention is lower in rigidity at high temperatures and has excellent heat resistance than the corrugated synthetic resin pipe made of polyethylene resin. I understood.

It is a principal part perspective view which shows the shape of the corrugated tube which concerns on this invention. It is the side view which looked at the corrugated tube of FIG. 1 from the pipe-axis direction. It is AA arrow sectional drawing of FIG. It is a BB arrow sectional view of Drawing 2. It is a perspective view which shows the structure of the male side coupling part formed in the one end part of a corrugated tube. It is a perspective view which shows the structure of the female side joint part formed in the other end part of a corrugated tube. It is DD sectional view taken on the line of FIG. It is EE arrow sectional drawing of FIG. It is FF arrow sectional drawing of FIG. It is GG arrow sectional drawing of FIG. (a) is the front view which shows the 1st form of a retaining ring, (b) is the side view. (a) is the front view which shows the 2nd form of a retaining ring, (b) is the side view. (a) is a front view which shows the 3rd form of a retaining ring, (b) is the side view. (a) is the front view which shows the 4th form of a retaining ring, (b) is the side view. (a) is the front view which shows the 5th form of a retaining ring, (b) is the side view. It is a side view which has a partial notch which shows the structure of the packing with which a male side coupling part is mounted | worn. It is sectional drawing which shows the state which the male side coupling part and the female side coupling part fitted. It is a perspective view which shows the structure of the pipe joint of this invention. It is a perspective view which shows the state which connected the corrugated pipe with the pipe joint. (a) is a front view of the packing attached to the pipe joint shown in FIG. 18, and (b) is a side view thereof. It is a perspective view which shows one structure of the pipe joint divided into two. It is a perspective view which shows the other structure of the pipe joint divided into two. It is a perspective view which shows the structure of the conventional square wave synthetic resin pipe | tube. It is sectional drawing which cut | disconnected the square wave synthetic resin pipe | tube of FIG. 23 from the direction orthogonal to a pipe-axis direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Corrugated pipe 2 Angular wave part 2a Outer peripheral surface 2b Protrusion part 3 Round wave part 3a Outer peripheral surface 4 Inner wall 5 Corner | angular part 10 Male side joint part 10a Insertion part 10b Large diameter part 10c Locking part 10d Inclined surface 10e Falling part 10f Inclined surface 10g Falling portion 10h Rib 10i Annular groove 20 Female side joint 20a Receiving portion 20b Retaining ring mounting portion 20c Shallow groove 20d Annular shallow groove 30 Retaining ring

Claims (10)

A corrugated synthetic resin tube in which a large number of round wave portions and angular wave portions are formed in the tube axis direction on the tube wall as viewed from the direction orthogonal to the tube axis direction,
The outline of the square wave portion is formed in a square circumscribing the outer circumference circle of the round wave portion as seen from the tube axis direction, and each corner portion of the square is formed on the outer circumference circle near the outside of the outer circumference circle. A corrugated synthetic resin pipe that is rounded along a circular arc and is made of a modified polyphenylene oxide.   2. The corrugated synthetic resin pipe is constructed by using two angular wave portions and one round wave portion continuous therewith as a basic pattern, and the basic pattern is repeatedly formed in the tube axis direction. Corrugated synthetic resin tube.   The corrugated synthetic resin pipe according to claim 1 or 2, wherein a male side joint is provided at one end of the corrugated synthetic resin and a female joint is provided at the other end. As the male joint portion, there are an insertion port extending from the end of the corrugated synthetic resin tube, and locking projections arranged at equal intervals on the circumference at the distal end of the insertion port. Prepared
The female-side joint portion includes a receiving portion that accommodates the insertion portion, and a retaining means that is provided in the receiving portion and locks a locking projection of the insertion portion. 3. The corrugated synthetic resin tube according to 3.   As the retaining means, an annular groove formed in the receiving portion, a ring-shaped support attached to the annular groove, and a state in which the ring-shaped support converges in a direction opposite to the insertion direction. A plurality of locking pieces that are extended, and these locking pieces are elastically deformed in a direction in which the locking protrusions are pressed to expand the tip when the insertion opening is inserted, and the locking pieces are 5. The corrugated synthetic resin pipe according to claim 4, wherein the corrugated synthetic resin pipe is configured to return to a converged state by passing the protruding protrusion and to lock the rear portion of the locking protrusion.   6. The corrugated synthetic resin pipe according to claim 5, wherein a slit is formed in at least one of the ring-shaped support body and the locking piece in the pipe axis direction. As the male side joint part, comprising an insertion part extending from the end of the corrugated synthetic resin pipe,
As the female side joint part, comprising a receiving part for storing the insertion part,
The tapered surface is formed in the outer peripheral surface of the said insertion part, and the inner peripheral surface of the said receiving part so that the outer peripheral surface of the said insertion part may closely_contact | adhere to the inner peripheral surface of the said receiving part. The corrugated synthetic resin tube described.   The corrugated synthetic resin pipe according to any one of claims 4 to 7, wherein a groove portion for mounting a ring-shaped sealing material is formed at a proximal end portion of the insertion portion. A pipe joint structure in which a pair of joint parts divided into two are attached to and fixed to the connecting portion of the corrugated synthetic resin pipe according to claim 1 or 2, wherein the joint part is
An arch that can be fitted into a trough between a round wave portion and a square wave portion in one corrugated synthetic resin tube, and a trough between a round wave portion and a square wave portion in the other corrugated synthetic resin tube An arch portion that can be, an arch portion that is in contact with the butted portions of the two corrugated synthetic resin pipes, and a connecting portion that connects the hem side end of each arch portion in the tube axis direction,
When the joint portion divided into two is attached to the corrugated synthetic resin pipe so as to be integrated, the connecting portions are opposed to each other and can be fastened and fixed by fastening means, and the connecting portion is formed of the angular wave portion. A pipe joint structure configured to fit in a corner space generated by being rounded into an arc shape at a corner.   The pipe joint structure according to claim 9, wherein a seal material is attached to an inner side of an arch portion attached to a butt portion of the corrugated synthetic resin pipe.

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