Curved trough, connection structure for curved trough, fixing structure for curved trough, and connection method for cable protective member to curved trough

Abstract

To provide a curved trough, etc., which is easily fixed to a foundation by an anchor bolt, etc., even in a case, e.g., where an installation target ground is a slope.SOLUTION: A curved trough 1 mainly consists of side plates 7 forming both side faces and a bottom plate 5 forming a bottom face. Both the side plates 7 are erected so as to enclose a curved part of the bottom plate 5, and a cross section is substantially U-shaped. In openings 9 of both ends of the curved trough 1, female joint structures 17a for connecting cable protective members are formed. In the curved part of the bottom plate 5, a bent part 11 is formed and a longitudinal rib 15 of the bent part 11 is available also as inside longitudinal ribs 15 of female joint structures 17a and 17b. On a rear face of the curved trough 1, a hollow columnar protrusion 27 protruding inward from the bottom plate 5 at a predetermined height is formed at a predetermined position in the space as mentioned above.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a curved trough in which a cable is laid, a connection structure for the curved trough in which this is used, a fixing structure for the curved trough, and a method for connecting a cable protection member to the curved trough. [Background technology]

[0002] In recent years, various structures have been proposed for laying cables used for transmitting electric power, etc. For example, a trough line has been proposed in which a plastic trough is installed and a cable is laid inside the trough. In such a trough line, a trough that corresponds to a bend at a predetermined angle is used.

[0003] For example, a cable trough has been proposed that does not require preparation of two types, one for bending to the right and one for bending to the left (Patent Document 1). In Patent Document 1, concave connection parts are formed at both ends of a directional trough body, and the concave connection parts of adjacent troughs are connected by a U-shaped connecting member. In this case, by using the body by flipping the base end and the tip end over, it becomes possible to bend in either the left or right direction.

[0004] Also, a trough for laying a branch cable has been disclosed, which includes a trough body having a notch on the side and a branch trough having one end joined to correspond to the notch (Patent Document 2). The trough of Patent Document 2 has a long groove on the cut surface of the notch, and the joint surface with the notch of the branch trough is closed by a gate plate removably attached to the long groove.

[0005] Also, a joint trough has been disclosed in which a flange for connection is provided at the end of the trough to form a flat-bending trough, a T-shaped branching trough, an up-down bending trough, etc., and each trough is connected to other troughs (Patent Document 3). In Patent Document 3, a cable-accommodating trough is made of reinforced plastic and is lightweight, and a cover is attached to the support shaft fitting part of the U-shaped main body so as to rotate by rotating support shafts on both sides and to be freely opened and closed. Also, the troughs are connected to each other by loose insertion fitting, so that they can be connected linearly and can be installed by bending at a small angle at the connecting part.

[0006] Also, a curved trough having male joint structures at both ends has been proposed (Patent Document 4). The curved trough of Patent Document 4 can be connected to each other by fitting the male joint structure at the end of the trough with a female joint structure provided at the end of another trough. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Utility Model Application Publication No. 6-5334 [Patent Document 2] Japanese Utility Model Application Publication No. 61-98328 [Patent Document 3] Japanese Utility Model Application Publication No. 5-130726 [Patent Document 4] US2020 / 0277739 A1 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the troughs of Patent Documents 1 to 4, none of them has a structure for fixing the trough to the installation ground. Therefore, in order to stably fix a conventional trough to, for example, a slope, it is necessary to directly drill holes in the bottom of the trough and fasten the bottom plate with bolts to fix it. However, if holes are drilled in the bottom plate of the trough and fastened with bolts, the bottom of the trough may crack or deform. Therefore, it is difficult to stably fix the trough to a slope.

[0009] The present invention has been made in consideration of such problems, and aims to provide a curved trough, etc. that can be easily fixed to the ground with anchor bolts, etc., even in cases where the ground on which it is to be installed is sloped, for example. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the first invention is The trough is a curved trough having a U-shaped cross section that surrounds the bottom plate and includes side plates that form both side surfaces and a bottom plate that forms a bottom surface, The bottom plate has a curved portion at a predetermined angle in a predetermined direction in a plan view, and the side plate on both sides of the side plate forming the inner curved portion and the side plate forming the outer curved portion rise upward so as to surround the curved portion of the bottom plate, The side plate forms a substantially arcuate curved portion that forms the outer curved portion and the inner curved portion. A generally U-shaped opening is formed at each end of the side plate, At the ends of the openings at both ends of the side plates and in the vicinity of the ends of the openings at both ends, substantially parallel vertical ribs are formed at both sides of the curved portion of each of the side plates, extending inward in a direction perpendicular to the curved portion and spaced apart by a predetermined distance from each other, thereby forming a pair of substantially U-shaped female joint structures facing each other in a plan view having the vertical ribs, Another female joint structure similar to the openings at both ends of the side plate is formed at a predetermined position in the middle of the bent portion that is a predetermined distance away from one end of the bent portion and in the vicinity of the predetermined position in the middle of the bent portion, The side plates of the inner curved portion and the outer curved portion are formed with bent portions, each of which functions as a vertical rib protruding inward, at a predetermined position near the opening and at a predetermined position intermediate the bent portion, the bent portions being spaced apart by a predetermined distance, The bent portion provided at a predetermined position near the opening also serves as an inner vertical rib of the female joint structure near the opening, and the bent portion formed at a predetermined position in the middle of the bent portion also serves as an inner vertical rib of the other female joint structure, A horizontal rib is formed on the upper portion of the bent portion, which also serves as a vertical rib, at a predetermined distance from each other at a predetermined position near the opening of the side plate and at a predetermined position between the bent portion and the side plate, to which a fixing metal fitting for attaching a lid can be attached so as to connect the vertical ribs to each other; It is desirable for the curved trough to be characterized in that the transverse ribs of the outer curved portion are longer than the transverse ribs of the inner curved portion, and no longitudinal ribs are provided on the outside of each of the side plates forming the inner curved portion and the outer curved portion.

[0011] In the present invention, the bent portion is formed by bending the curved lines forming the inner bent portion and the outer bent portion at a predetermined position of each bent portion so as to protrude inward. In this case, the bent portion does not mean the entire inward protruding portion including the bent portions on both sides, but means the bent portion on one side of each of the bent portions.

[0012] The bottom plate surfaces of the female joint structures formed at both ends of the bent portion are formed to be lower by a predetermined height than the bottom plate surfaces of the portions other than the female joint structure, The foot portion of the side plate of the female joint structure is formed to protrude from the back surface of the bottom plate at a predetermined height, and the bottom plate is supported by the foot portion at a predetermined height above the ground surface, thereby forming a space on the back surface of the bottom plate, The curved trough may be characterized in that a hollow columnar protrusion protruding downward from the bottom plate at a predetermined height is formed at a predetermined position in the space created by the inner curved portion and the outer curved portion formed on the back surface of the bottom plate, the top surface of the hollow columnar protrusion is either closed by the bottom plate or the top surface of the hollow columnar protrusion is open, and at least one of the hollow columnar protrusions is formed as an anchor bolt fixing portion.

[0013] A bottom reinforcing rib is formed on the back surface of the bottom plate, connecting the inner curved portion and the outer curved portion, and the bottom reinforcing rib may be formed at a different position separated from the hollow columnar protrusion in a direction toward the center of curvature of the inner curved portion and the outer curved portion.

[0014] A bottom reinforcement rib connecting the inner curved portion and the outer curved portion is formed on the back surface of the bottom plate, and the bottom reinforcement rib may be formed to sandwich the hollow columnar protrusion on the same straight line including the hollow columnar protrusion in a direction toward the center of curvature of the inner curved portion and the outer curved portion.

[0015] The trough may be provided with a curved trough structure having a bend angle smaller than the bend angle before cutting, which can be obtained by cutting the outer longitudinal ribs of the other female joint structures formed at a predetermined position between one end of the bent portion formed at both ends of the trough and the other end spaced a predetermined distance apart, the outer longitudinal ribs being formed substantially parallel to each other at a predetermined height in a direction perpendicular to the bottom plate so as to extend inward from the side plate, along the longitudinal ribs so as to connect the outer surfaces of the longitudinal ribs formed orthogonal to the curve forming the bent portion. Therefore, the curved trough can be cut out by cutting as necessary.

[0016] If the angle of the curved portion connecting the openings at both ends of the curved trough before cutting is 90°, the angle after cutting may be 60°, if the angle of the curved portion connecting the openings at both ends before cutting is 60°, the angle after cutting may be 45°, and if the angle of the curved portion connecting the openings at both ends before cutting is 45°, the angle after cutting may be 30°.

[0017] According to the first invention, as the shape of the female joint structure of the opening of the curved trough, ribs that are approximately parallel to each other are formed on both sides of the side plate at the opening end of the side plate and at a portion at a predetermined distance from the opening end of the side plate toward the inside, and a pair of approximately U-shaped female joint structures are formed so that the vertical ribs on both sides of the side plate face each other. In this way, since the female joint structure formed at the opening is a rib structure, it is possible to obtain the effect of reinforcing the end of the side plate, and further, since all of the vertical ribs formed at the bent portion in the present invention also serve as the inner vertical ribs formed at the opening of the female joint structure, it is not necessary to newly provide the approximately parallel U-shaped inner vertical ribs of the female joint structure, and it is sufficient to form only the outer vertical ribs, and the structure of the side plate can be simplified. At the same time, since the upper part of the inner vertical rib is supported by the horizontal rib, it has the effect of reinforcing the female joint structure.

[0018] Furthermore, there is no need to provide reinforcing vertical ribs on the outside of the two side panels of the inner curved section and the outer curved section, and the horizontal ribs reinforce the vertical ribs and can also be used as mounting points for fixing brackets to secure the trough lid. Furthermore, since the same female joint structure is formed on both ends of the bent portion, the bent portion can be used whether bent to the left or right.

[0019] Here, since both the inner and outer curved portions have curves in the same direction, the vertical ribs formed on the bent portion of the inner curved portion extend outward from the center of curvature, and the vertical ribs formed on the bent portion of the outer curved portion extend inward from the center of curvature, so that they are formed opposite to each other. In this case, the width between the vertical ribs of the approximately U-shaped opening on the inner curved portion side that forms a pair of approximately U-shaped female joint structures is smaller than the width between the vertical ribs of the opening in the bending direction of the approximately U-shaped opening on the opposing outer curved portion side.

[0020] In addition, a hollow columnar protrusion that protrudes downward from the bottom surface is provided on the back surface of the bottom plate of the curved trough. The hollow columnar protrusion functions as a bolt fixing structure, so anchor bolts can be fixed to the bolt fixing structure on normal gravel surfaces and ground, as well as on road surfaces such as asphalt and concrete, and on inclined surfaces, making it possible to install the product regardless of the ground conditions at the installation site. The bottom plate surface of the female joint structure formed at least at both ends of the bent portion may be formed at a predetermined height lower than the bottom plate surface of the portion other than the female joint structure. In this way, when the male joint structure of another trough is overlapped and connected to the bent trough, the levels of the upper surfaces of the bottoms of the other trough and the bent trough can be aligned, and the cable can be arranged approximately horizontally in the trough, thereby preventing the cable from being arranged at an angle and excess tension from being applied to the cable.

[0021] In addition, forming the hollow columnar protrusion has the effect of reinforcing the thin bottom plate. Therefore, even if a hole is drilled in the thin bottom plate, microcracks do not occur in the hole processing part of the bottom plate. In addition, since the load caused by tightening when the anchor bolt is fixed is received by the hollow columnar protrusion, deformation of the bottom plate and the occurrence of microcracks can be prevented compared to the case where an anchor bolt fixing hole is directly provided in the bottom plate. In addition, since the thin bottom plate is present on the upper part of the hollow columnar protrusion, the inside of the hollow columnar protrusion is hollow and only the top surface is blocked by the thin bottom plate, so that it is easy to drill holes in the hollow columnar protrusion.

[0022] Furthermore, by providing the hollow protrusion, the bottom plate can be set a predetermined distance higher from the ground, so that the height of the cable storage section of the other trough connected to the curved trough can be made approximately the same. Also, since the tightening force when fixing the anchor bolt is directly received by the hollow columnar protrusion, the bottom plate will not deform even when the anchor bolt is tightened. By providing the hollow columnar protrusion on the back surface of the bottom plate, the bottom plate can be held high, so a predetermined space can be secured on the back surface of the bottom plate, improving the ease of installation of the trough.

[0023] In addition, the side plates protrude from the back surface of the bottom plate at a predetermined height to form feet, and the feet support the bottom plate at a predetermined height above the ground surface. This allows a space to be formed on the back surface of the bottom plate. For example, normally, when ground adjustment is not required, the bottom plate can be lowered, but when the ground is uneven, lowering the bottom plate interferes with the bottom surface of the curved trough, causing problems in installation. However, since the bottom plate of the curved trough is separated from the ground by a predetermined height, it is possible to suppress the influence of unevenness in the ground when installing the curved trough.

[0024] In addition, the vertical ribs on the inside of the side panels formed at both ends and in the middle of the bent portion, and the horizontal ribs connecting the vertical ribs, both have the effect of reinforcing the side panels at the bent portion. In this way, the bent portion of the side panels, the horizontal ribs, and the vertical ribs are integrally formed with the horizontal rib in between, and because the reinforcing effects are superimposed, there is no need to provide vertical ribs on the outside of the two inner and outer side panels. The horizontal ribs can also reinforce the vertical ribs, and can also be used as mounting points for fixing brackets to fix the trough lid.

[0025] In addition, by forming reinforcing ribs on the back surface of the bottom plate at different positions spaced a predetermined distance from the hollow columnar protrusion and in a direction toward the center of curvature of the inner curved portion and the outer curved portion, the bottom plate can be reinforced more efficiently.

[0026] Similarly, by forming reinforcing ribs on the back surface of the bottom plate in the direction toward the center of curvature of the inner curved portion and the outer curved portion on the same straight line including the hollow columnar protrusion, the bottom plate can be reinforced more efficiently.

[0027] In addition to the openings at both ends, parallel ribs for forming a female joint structure are formed at a predetermined position in the middle of the bent portion, so that the portion can be cut and used. In other words, a bent trough with a small bend angle may be built into the entire bent trough. Therefore, the bent trough can be cut along the outside of the parallel ribs of the female joint structure at a predetermined position in the middle of the bent portion and used. In other words, by cutting at the end of the built-in female joint structure, it can be used as a bent trough with a bend angle smaller than the bend angle before cutting. In addition, the vertical rib provided at a predetermined position in the middle of the bent portion can be used as a mark for the cutting position when cutting the bent trough.

[0028] In addition, the bottom plate surface of the female joint structure formed at both ends of the bent portion and / or the bottom plate surface of the female joint structure formed at a predetermined position in the middle of the bent portion may be formed lower than the bottom plate surface of the portion other than the female joint structure by the height of the bottom plate of the male joint structure. By doing so, even in the case of a normal bent trough or a bent trough with a small bend angle cut at the middle position of the bent portion, when the male joint structure of another trough is overlapped and connected to the female joint structure of the bent trough, the level of the upper surface position of the bottom of the bent trough can be matched with the height of the other trough. As a result, by arranging the cable in the trough approximately horizontally, it is possible to prevent the cable from being arranged obliquely and causing excess tension to act on the cable.

[0029] In this case, for example, if the angle of the curved part connecting the openings at both ends of the curved trough before cutting is 90°, the angle after cutting can be set to 60°, and if the angle of the curved part connecting the openings at both ends before cutting is 60°, the angle after cutting can be set to 45°; thus, the angle of curvature can be adjusted by cutting.

[0030] The second invention is a connection structure for a curved trough and a straight trough relating to the first invention, characterized in that a male joint structure of a straight trough of a predetermined length and having approximately the same cross-sectional dimensions as the curved trough and the trough body is connected to the female joint structure of either of the openings at both ends of the curved trough.

[0031] The first invention may also provide a connection structure for a curved trough and a straight trough, characterized in that the female joint structure of the opening at either end of the curved trough is connected to the female joint structure of a straight trough of a predetermined length, the cross-sectional dimensions of which are approximately the same as those of the curved trough and the trough body, via a male-male conversion connection adapter.

[0032] The first aspect of the present invention also relates to a connection structure between a curved trough and a small diameter trough, wherein a rectangular end plate wider than the distance between the opposing vertical ribs of the female joint structure is inserted into the female joint structure of the opening at either end of the curved trough, the end plate being approximately U-shaped with an opening of a predetermined size formed either below or above, and a male joint structure of the small diameter trough is arranged in the opening of the end plate, and a flange portion of the male joint structure of the small diameter trough is fitted into the opening of the end plate as a slip-out prevention structure to connect the male joint structure of the small diameter trough, thereby fixing the male joint structure of the small diameter trough to the end plate.

[0033] The first aspect of the present invention also provides a connection structure between a bent trough and an electric conduit, wherein the electric conduit connected to the bent trough has an independent wave structure, and is either an independent wave electric conduit having a small diameter portion with a circular cross section, or a rectangular electric conduit in which large diameter portions with a rectangular cross section and small diameter portions with a circular cross section are alternately formed, and a half-split end plate that can be separated into an upper and lower part is disposed in the female joint structure of the opening of any of the bent troughs, and the end plate has openings in opposing positions when separated, and the small diameter portion of the electric conduit is sandwiched in the opening of the end plate, thereby fixing the electric conduit to the end plate.

[0034] A first aspect of the present invention provides a connection structure between a bent trough and a conduit, the conduit being connected to the bent trough is a helical wave conduit having a helical wave structure with a circular cross section, and the connection structure includes an inner connection member having a cylindrical portion with a circular cross section having a helical groove that can be fitted to an inner circumferential surface of the conduit and a flange portion formed at an end of the cylindrical portion, and an outer connection member having a cylindrical portion with a circular cross section having a helical groove that can be fitted to an outer circumferential surface of the conduit and a flange portion formed at an end of the cylindrical portion, and the inner connection member and the outer connection member are connected to each other. The connection structure for a bent trough may be characterized in that the tubular portion of the outer connection member is screwed onto the inner and outer peripheral surfaces of the conduit, respectively, and attached to the end of the conduit, the outer connection member is positioned further back from the end of the conduit than the inner connection member, an end plate having an opening through which the conduit can be inserted is positioned in the female joint structure of the opening, and the conduit is fixed by sandwiching the end plate between the flange portion of the inner connection member and the flange portion of the outer connection member.

[0035] In the second invention, a groove having a predetermined length in the width direction of the trough is formed at approximately the center of the surface of the bottom plate, which is the bottom of the female joint structure consisting of a pair of approximately C-shaped shapes extending inward and facing each other, and a protrusion capable of fitting into the groove may be provided at the bottom tip of the end plate.

[0036] According to the second invention, by positioning the male joint structure of the straight trough so as to drop from above into the approximately parallel space created by the ribs of the female joint structure of the curved trough, the straight trough can be directly connected to the opening of the curved trough.

[0037] In addition, by using a male-male conversion connection adapter, the female joint structure of the curved trough can be connected to the female joint structure of another straight trough in an opposing relationship.

[0038] In addition, by using an end panel having an approximately U-shaped, generally rectangular shape with an opening of a predetermined size formed below or above the center, it is possible to connect a small diameter straight trough and a curved trough.

[0039] In addition, by using an end plate that can be separated into upper and lower parts and has an opening of a specified size, both an independently corrugated circular cross-sectional conduit and a square conduit having rectangular large and small diameter sections can be connected to the bent trough.

[0040] In addition, the bent trough and the helical wave conduit can be connected by attaching an inner connecting member having a flange portion and an outer connecting member having a flange portion to the end of the helical wave conduit and sandwiching an end plate fixed to the opening of the bent trough between both flange portions.

[0041] In addition, by inserting the bottom tip of the end plate into the groove provided at the bottom of the female joint structure of the curved trough, the end plate can be fixed more stably and at the same time, the end plate can be prevented from rotating in the width direction. Also, when using an end plate with a half-split structure, the same effect can be obtained by inserting the upper end plate into the recess of the lower end plate.

[0042] The third invention is a fixing structure for a curved trough according to the first invention, characterized in that the hollow columnar protrusion protruding downward from the back surface of the bottom plate at a predetermined height is formed as an anchor bolt fixing portion, the hollow columnar protrusion has a hollow cylindrical structure, and the curved trough is fixed to asphalt or concrete ground by inserting an anchor bolt into the hollow portion of the hollow cylindrical structure and tightening it.

[0043] According to the third aspect of the present invention, the curved trough can be reliably fixed to the ground, for example, on a slope, by fixing the curved trough to the ground with an anchor bolt using the hollow columnar protrusion. In this case, the hollow columnar protrusion can reinforce the thin bottom plate, thereby suppressing the occurrence of cracks in the bottom plate.

[0044] A fourth invention is a method for connecting a cable protection member to a curved trough according to the first invention, characterized in that in the female joint structure formed by extending the vertical ribs of a predetermined height substantially parallel to each other in a vertical direction inward from the side plates at the ends of the opening at both ends of the curved trough and at a position near the ends of the opening and a predetermined distance away from the ends of the opening, the method comprises fixing a small diameter portion of the male joint structure of the trough directly to a space in which both end faces formed by the vertical ribs are substantially parallel, or fixing the small diameter portion of the male joint structure of the trough via an end plate, or fixing a small diameter portion of an independent wave conduit having a circular or rectangular cross section or an end of a helical wave conduit via an end plate.

[0045] According to the fourth aspect of the present invention, it becomes possible to connect various cable protection members to the female joint structure of the curved trough via the end plate. Effect of the Invention

[0046] According to the present invention, it is possible to provide a curved trough or the like that can be easily fixed to the ground with anchor bolts or the like, even when the ground on which the trough is to be installed is sloped, for example. [Brief description of the drawings]

[0047] [Figure 1] 1 is a top perspective view showing the curved trough 1 and the trough lid 3. FIG. [Diagram 2] FIG. [Diagram 3] (a) is a plan view of the curved trough 1, and (b) is a bottom view of the curved trough 1. [Figure 4] 1A and 1B are bottom views of another curved trough 1, in which (a) both a bottom reinforcing rib 29 and a hollow columnar protrusion 27 are provided on the bottom surface of the trough, and (b) a bottom view of a trough with multiple hollow columnar protrusions 27 provided on the bottom surface of the trough. [Diagram 5] 4(a) to 4(c) are enlarged views of a hollow columnar protrusion 27, illustrating the processing steps. [Figure 6]FIG. 4 shows a curved trough fixing structure 40. [Figure 7] (a) is a plan view of the curved trough 1 before cutting, and (b) is a plan view of the curved trough 1 after cutting. [Figure 8] A diagram showing the angle of the curved trough 1. [Figure 9] 4(a) and (b) are diagrams showing the process of constructing the trough connection structure 50. [Figure 10] 4 is an enlarged view of the trough connection structure 50. FIG. [Figure 11] 6(a) and (b) are diagrams showing a process of constructing a trough connection structure 50a. [Figure 12] 6(a) and (b) are enlarged views showing a process of constructing the trough connection structure 50a. [Figure 13] 6(a) and (b) are diagrams showing a process of constructing a trough connection structure 50b. [Figure 14] 5A is a front view showing an end plate 53, and FIG. 5B is a plan view showing a male joint structure 43a of a small diameter trough 47. FIG. [Figure 15] 13(a) and (b) are diagrams showing a process of constructing a trough connection structure 50c. [Figure 16] 13(a) and (b) are enlarged views of an end plate 53a in a process of constructing a trough connection structure 50c. [Figure 17] 1A is a diagram showing a trough connection structure 50d, and FIG. 1B is an enlarged view of an end plate 53a. [Figure 18] 13A and 13B are diagrams showing a process of fixing an inner connection member 57a and an outer connection member 57b to a helical wave conduit 61b. [Figure 19] A diagram showing a trough connection structure 50e. [Figure 20] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an upper perspective view showing a curved trough 1 and a trough cover 3, Fig. 2 is a lower perspective view of the curved trough 1, Fig. 3(a) is a plan view of the curved trough 1, and Fig. 3(b) is a bottom view of the curved trough 1. The curved trough 1 mainly comprises side plates 7 forming both side surfaces and a bottom plate 5 forming the bottom surface, both side plates 7 standing up to surround the bottom plate 5, and has a substantially U-shaped cross section. The curved trough 1 and the trough cover 3 are made of, for example, resin, and are molded by press molding or injection molding.

[0049] As shown in Fig. 3(a) etc., the bottom plate 5 has a curved portion at a predetermined angle in a predetermined direction in a plan view. The curved portion is made up of an inner curved portion 19 that forms the inside of the curve, and an outer curved portion 21 that forms the outside of the curve. The side plate 7 that forms the inner curved portion 19 and the side plate 7 on both sides that form the outer curved portion 21 rise upward from the curved portion of the bottom plate 5 so as to surround the curved portion of the bottom plate 5. An approximately U-shaped opening 9 is formed at both ends of the side plate 7 that forms the inner curved portion 19 and the side plate 7 that forms the outer curved portion 21.

[0050] At the ends of the openings 9 at both ends of the side plate 7 and at predetermined positions near the ends of the openings 9 at both ends, substantially parallel vertical ribs 15 are formed at a predetermined distance from each other and extend inward in a direction perpendicular to the curved portion on both sides of the curved portion of each side plate 7, thereby forming a pair of substantially U-shaped female joint structures 17a facing each other in a plan view having the vertical ribs 15. The female joint structures 17a are formed such that the respective vertical ribs 15 extend inward from the opposing side plates 7 in a direction perpendicular to the curved portion. In other words, the female joint structures 17a are substantially U-shaped facing each other in a plan view.

[0051] A pair of mutually opposing, substantially U-shaped, other female joint structures 17b are formed at a predetermined position in the middle of the bent portion, a predetermined distance away from one end of the bent portion, and in the vicinity of the predetermined position in the middle of the bent portion, similar to the openings 9 at both ends of the side plate 7. The female joint structures 17b formed at a predetermined position in the middle of the bent portion have substantially parallel vertical ribs 15 of a predetermined height formed inwardly from each of the opposing side plates 7 perpendicular to the bent portion, facing each other at a predetermined position in the middle of the bent portion, a predetermined distance away from one end of the bent portion, and in the vicinity of the predetermined position in the middle of the bent portion.

[0052] As described above, the side plate 7 forms a substantially arc-shaped curved portion that forms the outer curved portion 21 and the inner curved portion 19. The side plate 7 of the inner curved portion 19 and the outer curved portion 21 is formed with a bent portion 11, which also functions as a vertical rib 15 that protrudes inwardly so as to connect the inner curved portion 19 and the outer curved portion 21, at a predetermined position near the opening 9 and a predetermined position in the middle of the curved portion, at a predetermined distance apart. The bent portion 11 is provided so as to connect a predetermined position in the middle of the curved portion between the opening 9 at one end of the curved trough 1 and the other end that is a predetermined distance away from the one end.

[0053] Furthermore, the vertical rib of the bent portion 11 not only reinforces the side plate 7, but also serves as the inner vertical rib 15 of the approximately U-shaped female joint structure 17a and the inner vertical rib 15 of the approximately U-shaped female joint structure 17b formed at a predetermined position in the middle of the bent portion. That is, one end portion corresponding to a predetermined position near the opening 9 of the bent portion 11 also serves as the inner vertical rib 15 of the female joint structure 17a near the opening 9, and the other end portion corresponding to a predetermined position in the middle of the bent portion of the bent portion 11 also serves as the inner vertical rib 15 of another female joint structure 17b.

[0054] Horizontal ribs 13 are provided at both ends of the upper part of the bent portion 11, which also serves as the vertical ribs and are formed at a predetermined distance from each other at a predetermined position near the opening 9 of the side plate 7 and at a predetermined position in the middle of the bent portion. The horizontal ribs 13 are formed to connect the inner vertical ribs 15 of the female joint structure 17a at both ends of the bent portion 11 and the inner vertical ribs 15 of the female joint structure 17b formed at a predetermined position in the middle of the bent portion. That is, the horizontal ribs 13 are formed to connect the vertical ribs 15 formed at both ends of the bent portion 11. A fixing bracket for attaching the trough lid 3 can be attached to the horizontal rib 13. In this way, the horizontal ribs 13 also serve as a fixing bracket attachment portion for attaching a fixing bracket for attaching the trough lid, so that when the trough lid 3 is placed on the curved trough 1, the trough lid 3 can be fixed to the horizontal ribs 13 of the curved trough 1 using a fixing bracket not shown.

[0055] The transverse ribs 13 are formed in a substantially horizontal direction so as to be perpendicular to the vertical ribs 15 which are formed in a substantially vertical direction. Both ends of the transverse ribs 13 of the inner curved portion 19 and both ends of the transverse ribs 13 of the outer curved portion 21 are respectively disposed on the same center line from the center of curvature of the curved portion. In other words, the transverse ribs 13 of the outer curved portion 21 are formed longer than the transverse ribs 13 of the inner curved portion 19. Furthermore, it is not necessary to provide vertical ribs on the outsides of the side plates 7 which form the inner curved portion 19 and the outer curved portion 21.

[0056] In addition, the bottom plate surface of the female joint structure 17a formed at least at both ends of the bent portion is formed at a predetermined height lower than the bottom plate surface of the portion other than the female joint structure 17a. In this way, when the male joint structure of another trough is overlapped and connected to the female joint structure 17a, the level of the upper surface position of the bottom of the other trough and the curved trough 1 can be aligned. In addition, a groove 23 having a predetermined length in the width direction of the trough is formed in the approximate center of the surface of the bottom plate 5, which is the bottom of a pair of approximately U-shaped female joint structures 17a facing each other in a plan view. The function of the groove 23 will be described later.

[0057] 2 and 3(b), in the female joint structure 17a, the side plate 7 protrudes at a predetermined height from the rear surface of the bottom plate 5 to form the foot 25. That is, on the bottom surface side of the curved trough 1, the foot 25 protrudes downward, and most of the bottom surface of the bottom plate 5 other than the foot 25 is located higher than the foot 25. Therefore, when the curved trough 1 is installed on the ground, the bottom plate 5 is supported by the foot 25 at a predetermined height above the ground surface, and a space is formed on the rear surface of the bottom plate 5.

[0058] On the back surface of the bottom plate 5, at a predetermined position in the aforementioned space created by the inner curved portion 19 and the outer curved portion 21, a hollow columnar protrusion 27 is formed that protrudes downward from the bottom plate 5 at a predetermined height. In addition, on the back surface of the bottom plate 5, a bottom reinforcing rib 29 is formed that connects the inner curved portion 19 and the outer curved portion 21. The bottom reinforcing rib 29 is formed along a direction toward the center of curvature of the inner curved portion 19 and the outer curved portion 21. At this time, the bottom reinforcing rib 29 is formed so as to sandwich the hollow columnar protrusion 27 on the same straight line including the hollow columnar protrusion 27. Here, by integrating the bottom reinforcing rib 29 and the hollow columnar protrusion 27, the part of the hollow columnar protrusion 27 is formed into a thick-walled cylindrical shape, and the bottom reinforcing rib 29 is supported by this thick-walled cylindrical shape, so such a structure is preferable.

[0059] The bottom reinforcement rib 29 does not have to be formed on the same straight line including the hollow columnar protrusion 27 as shown in Fig. 3(b). Fig. 4(a) is a diagram showing another embodiment of the bottom reinforcement rib 29. In the example shown in Fig. 4(a), the bottom reinforcement rib 29 is formed at a different position apart from the hollow columnar protrusion 27 in the direction toward the center of curvature of the inner curved portion 19 and the outer curved portion 21. In this way, the arrangement of the bottom reinforcement rib 29 is not particularly limited.

[0060] In addition, in Fig. 4(a), the bottom reinforcing rib 29 is provided so as to sandwich the hollow columnar protrusion 27, but this rib is not necessarily provided. However, it goes without saying that the combination of the bottom reinforcing rib 29 and the hollow columnar protrusion 27 can further reinforce the bottom plate 5 of the trough. Therefore, it is more preferable to arrange them in combination.

[0061] In Figure 4(b), the hollow columnar protrusion 27 is provided on the back surface of the bottom plate 5 in the widthwise center between the bending portion 11 of the inner bending portion 19 of the side panel 7 and the bending portion 11 of the outer bending portion 21, and further on the back surface of the bottom plate 5 in the widthwise center between the female joint structure 17b provided in the middle of the bending portion a predetermined distance away from one end further beyond that and the female joint structure 17a provided at the other end of the bending portion.

[0062] Here, even if the bottom reinforcing rib 29 is not provided, the bottom can be sufficiently reinforced by providing one or more hollow columnar protrusions 27 as necessary as shown in Fig. 4(b). In this case, the end of the side plate may or may not have a rib with a bent structure only near the end of the side plate.

[0063] 5(a) is an enlarged cross-sectional view of the vicinity of the hollow columnar protrusion 27. As shown in the figure, the hollow columnar protrusion 27 is substantially circular (cylindrical) and hollow at the bottom. That is, the top of the hollow columnar protrusion 27 is closed by the bottom plate 5. Also, a minute recess is formed on the top surface of the bottom plate 5 above the hollow columnar protrusion 27. For example, it is desirable that the outer diameter of the hollow columnar protrusion 27 is about 33 mm, the inner diameter (hole) is 10 mm, and the height (protruding height from the bottom surface of the bottom plate 5) is at least 8 mm or more and 30 mm or less.

[0064] In order to use the hollow columnar protrusion 27, first, as shown in FIG. 5(b), a hole of a predetermined size is provided in the bottom plate 5 above the hollow columnar protrusion 27, using the above-mentioned minute recess as a marker. At this time, the hole provided in the bottom plate 5 is larger than the inner diameter of the hollow of the hollow columnar protrusion 27. Next, as shown in FIG. 5(c), a hole of approximately the same diameter as the hollow of the hollow columnar protrusion 27 is provided from above or below, so that the upper surface side of the bottom plate 5 and the lower part of the hollow columnar protrusion 27 are communicated. In this way, two stages of anchor bolt insertion holes with a larger inner diameter at the top may be formed, but a hole of approximately the same diameter as the hollow of the hollow columnar protrusion 27 and a hole of the same diameter as the hollow inner diameter of the hollow columnar protrusion 27 may also be provided.

[0065] 6 is a diagram showing a curved trough fixing structure 40 in which the curved trough 1 is fixed to a ground surface 31 after being processed in this manner. A hollow columnar protrusion 27 that protrudes downward from the rear surface of the bottom plate 5 at a predetermined height is formed as a fixing portion for an anchor bolt 35. The hollow columnar protrusion 27 has a hollow cylindrical structure, and the curved trough 1 is fixed to a ground surface 31 such as an asphalt or concrete ground by inserting the anchor bolt 35 into the hollow portion of the hollow cylindrical structure and tightening it.

[0066] At this time, as described above, a foot 25 protruding downward is formed at the end of the curved trough 1. Therefore, in the curved trough fixing structure 40 in which the curved trough 1 is fixed to the ground surface 31, a space 33 is formed between the bottom plate 5 and the ground surface 31.

[0067] When the anchor bolts 35 are not used for fixing, the top surface of the hollow columnar protrusion 27 is blocked by the bottom plate 5 as shown in Fig. 5(a), so that it is possible to prevent foreign matter from entering the inside from below the curved trough 1. On the other hand, when the anchor bolts 35 are used for fixing, the top surface of the hollow columnar protrusion 27 may be opened in advance. That is, the top surface of the hollow columnar protrusion 27 may be blocked by the bottom plate 5, or the top surface of the hollow columnar protrusion 27 may be open.

[0068] The shape of the hollow columnar protrusion 27 may be substantially cylindrical as shown in the figure, or may be substantially rectangular, polygonal, or other shapes that can form an anchor bolt fixing hole. The hollow columnar protrusion 27 may be disposed in multiple locations. That is, at least one hollow columnar protrusion 27 may be provided and formed as an anchor bolt fixing portion. By providing at least two or more hollow columnar protrusions 27, the bottom plate 5 can be reinforced with the hollow columnar protrusions 27, and the linear ribs provided on the bottom plate 5 can be omitted, which further improves the ease of installation.

[0069] Next, an example of a method of using the curved trough 1 will be described. Fig. 7(a) is a plan view of the curved trough 1. As described above, the curved trough 1 has a female joint structure 17b formed in the middle of the curved portion, in addition to the female joint structure 17a formed in the openings 9 at both ends. That is, the vertical ribs 15 are formed in a direction perpendicular to the bottom plate 5 and of a predetermined height so as to extend inward from the side plate 7 and are approximately parallel to each other, in the female joint structure 17b formed at a predetermined position in the middle between one end of the curved portion formed at both ends of the curved trough 1 and the other end at a predetermined distance away, and in a predetermined position in the vicinity of the position.

[0070] The outer vertical ribs 15 of the female joint structure 17b are formed to be substantially parallel to each other at a predetermined height in a direction perpendicular to the bottom plate 5 so as to extend inward from the side plate 7, and are cut along the vertical ribs 15 so as to connect the outer surfaces of the vertical ribs 15 formed perpendicular to the curve forming the bent portion (line A in the figure). By cutting in this manner, as shown in FIG. 7(b), it can be used as a curved trough 1 having a bending angle smaller than the bending angle before cutting. In other words, the curved trough 1 before cutting has a built-in structure of a curved trough having a bending angle smaller than the bending angle before cutting, which can be obtained by cutting.

[0071] The curved trough 1 cut in this way has the female joint structure 17a formed at the opening 9 before cutting formed at one end, and the female joint structure 17b formed at a predetermined position in the middle of the curved part before cutting formed at the other end. In other words, since the same female joint structures 17a, 17b are formed at both ends of the curved shape, other troughs can be connected to each end and used in the same way as the curved trough 1 before cutting.

[0072] FIG. 8 is a diagram showing the bending angle of such a curved trough 1. For example, when the bending angle (θ1 in the figure) of the curved part connecting the openings 9 at both ends of the curved trough 1 before cutting is 45°, the bending angle (θ2 in the figure) after cutting is 30°. When the bending angle (θ1 in the figure) of the curved part connecting the openings 9 at both ends of the curved trough 1 before cutting is 60°, the bending angle (θ2 in the figure) after cutting is 45°. When the bending angle (θ1 in the figure) of the curved part connecting the openings 9 at both ends of the curved trough 1 before cutting is 90°, the bending angle (θ2 in the figure) after cutting is 60°. In this way, the bending angle can be adjusted by cutting. Also, as described above, even if the curved trough 1 has a small bending angle after cutting, it can be connected to other troughs, etc., because it has female joint structures 17a and 17b at both ends.

[0073] Next, a trough connection structure using a curved trough 1 will be described. Figures 9(a) and 9(b) are diagrams showing a connection process of a connection structure (trough connection structure 50) between a curved trough 1 and a straight trough 41. The straight trough 41 has a male joint structure 43 at one end and a female joint structure 45 at the other end. A plurality of straight troughs 41 are arranged in the longitudinal direction, and the male joint structure 43 of one adjacent straight trough 41 is connected by dropping it from above the female joint structure 45 of the other adjacent straight trough 41, so that the female joint structure 45 and the male joint structure 43 can be fitted together.

[0074] In the trough connection structure 50, as shown in Figure 9(a), the female joint structure 17a at the opening 9 of the curved trough 1 and the male joint structure 43 of the straight trough 41 are arranged opposite each other, and the male joint structure 43 of the straight trough 41 is dropped into the female joint structure 17a of the curved trough 1, thereby connecting the curved trough 1 and the straight trough 41 as shown in Figure 9(b).

[0075] FIG. 10 is a partially enlarged view of the trough connection structure 50 in FIG. 9(b). As described above, the female joint structure 17a is formed by vertical ribs parallel to each other. The male joint structure 43 has a flange portion whose end is widened, and the flange portion fits between the vertical ribs of the female joint structure 17a to connect the two. In this way, in the trough connection structure 50, the male joint structure 43 of the straight trough 41 of a predetermined length in which the cross-sectional dimensions of the curved trough 1 and the trough body are approximately the same is connected to the female joint structure 17a of either opening 9 at both ends of the curved trough 1. Note that when the curved trough 1 is cut, the male joint structure 43 of the straight trough 41 may be connected to the female joint structure 17b, and the same applies to each of the following embodiments.

[0076] Next, a description will be given of another trough connection structure using the curved trough 1. Figures 11(a) and 11(b) are diagrams showing a connection process of a connection structure (trough connection structure 50a) between the curved trough 1 and the straight trough 41.

[0077] In the trough connection structure 50a, as shown in Fig. 11(a), the female joint structure 17a at the opening 9 of the curved trough 1 and the female joint structure 45 of the straight trough 41 are disposed opposite each other. That is, the female joint structures of the curved trough 1 and the straight trough 41 face each other.

[0078] 12(a) is an enlarged view of the female joint structure 17a of the curved trough 1 and the female joint structure 45 of the straight trough 41 arranged opposite each other. As described above, each female joint structure 17a, 45 is formed into a substantially U-shape by parallel vertical ribs. That is, the U-shaped portions of each female joint structure 17a, 45 are arranged side by side, with the openings facing each other.

[0079] As shown in Fig. 12(b), in this embodiment, a male / female conversion connection adapter 51 is used. The male / female conversion connection adapter 51 has a shape in which the center in the thickness direction is cut out at both ends in the width direction. In other words, both ends in the width direction of the male / female conversion connection adapter 51 are roughly U-shaped and open outward in a plan view.

[0080] The male-male conversion connection adapter 51 may be a flat plate-like structure with roughly U-shaped openings at both ends that open outward, or may be a structure that has a roughly U-shaped bent structure with a notch in the center provided by roughly U-shaped, roughly parallel fitting parts. In either case, two opposing female joint structures are fitted together in a roughly U-shaped configuration that opens outward.

[0081] The male / male conversion connection adapter 51 is disposed so as to straddle the female joint structure 17a of the curved trough 1 and the female joint structure 45 of the straight trough 41, and the female joint structure 17a and the female joint structure 45 can be connected by fitting the vertical ribs of the female joint structure 17a and the female joint structure 45 into the cutout portion in the center of the male / male conversion connection adapter 51. In this manner, in the trough connection structure 50a, the female joint structure 45 of the straight trough of a predetermined length, in which the cross-sectional dimensions of the curved trough 1 and the trough body are substantially the same, is connected to the female joint structure 17a of either opening 9 at both ends of the curved trough 1 via the male / male conversion connection adapter 51.

[0082] Next, a description will be given of another trough connection structure using the curved trough 1. Figures 13(a) and 13(b) are diagrams showing a connection process of a connection structure (trough connection structure 50b) using an end plate between the curved trough 1 and the small diameter trough 47.

[0083] The small diameter trough 47 is a straight trough with approximately the same cross-sectional shape as the straight trough 41 described above, and has a male joint structure 43a at one end and a female joint structure 45a at the other end. As described above, the small diameter troughs 47 can be connected to each other by linking their male joint structures 43a and female joint structures 45a. On the other hand, the small diameter trough 47 has a smaller width and height than the straight trough 41. For this reason, the female joint structure 17a of the curved trough 1 and the male joint structure 43a of the small diameter trough 47 cannot be directly connected.

[0084] Therefore, in this embodiment, an end plate 53 is used. FIG. 14(a) is a front view of the end plate 53. The end plate 53 is substantially U-shaped with an opening 55 of a predetermined size (width B in the figure) formed either on the lower or upper side. On the other hand, as shown in FIG. 14(b), in the male joint structure 43a of the small diameter trough 47, the width of the flange portion at the tip is D, and the width on the inner side is configured as width C smaller than the width D of the flange portion. In this case, since the respective dimensions are configured as D>B>C, by inserting the end plate 53 into the width C portion of the male joint structure 43a of the small diameter trough 47, the flange portion of the wide male joint structure 43a is engaged by the end plate 53.

[0085] As shown in Fig. 14(b), in the trough connection structure 50b, the male joint structure 43a of the small diameter trough 47 is disposed in the opening 55 of the end plate 53, and the flange portion of the male joint structure 43a of the small diameter trough 47 is fitted into the opening 55 of the end plate 53 as a retaining structure to be connected. In this manner, the male joint structure 43a of the small diameter trough 47 is fixed to the end plate 53. Here, even if a pulling force is applied to the small diameter trough 47, the male joint structure 43a abuts against the end plate 53, so that the small diameter trough 47 will not come out of the bent trough 1.

[0086] The end plate 53 has a rectangular shape that is wider than the distance between the opposing vertical ribs 15 of the female joint structure 17a of the opening 9 at either end of the curved trough 1. Therefore, when the end plate 53 is inserted between the vertical ribs of the female joint structure 17a, the end plate 53 is fixed to the female joint structure 17a. It is preferable that the end plate 53 has a predetermined thickness so that the end plate 53 does not rotate obliquely from the opening 9 when placed in the female joint structure 17a of the opening 9.

[0087] Next, a description will be given of a conduit connection structure, which is another cable protection member, using the bent trough 1. Figures 15(a) and 15(b) are diagrams showing a connection process of the bent trough 1 and the conduit connection structure (trough connection structure 50c).

[0088] In this embodiment, the conduit connected to the bent trough 1 is a rectangular conduit 61 having an independent wave structure. The rectangular conduit 61 has large diameter portions 63 with a rectangular cross section and small diameter portions 65 with a circular cross section formed alternately. In addition, an end plate 53a having a half structure and capable of being separated into upper and lower portions is disposed in the female joint structure 17a of the opening 9 at either end of the bent trough 1.

[0089] 16(a) is a front view showing the end plate 53a. As described above, the end plate 53a can be divided into upper and lower parts, and openings 55a are formed at the parts facing each other when divided. In the illustrated example, the openings 55a are semicircular, and when the divided end plates 53a are butted against each other, the openings 55a become substantially circular. It is preferable that the thickness of the end plate 53a is also a predetermined thickness so that the end plate 53a does not rotate obliquely from the opening 9 when placed in the female joint structure 17a of the opening 9.

[0090] The inner diameter of the substantially circular opening 55a formed at this time is slightly larger than the outer diameter of the small diameter portion 65 of the rectangular electric conduit 61, and is smaller than the outer diameter (length of a side) of the large diameter portion 63 of the rectangular electric conduit 61. Therefore, as shown in FIG. 16(b), the small diameter portion 65 of the rectangular electric conduit 61 is sandwiched between the opening 55a of the end plate 53a, so that the rectangular electric conduit 61 is fixed to the end plate 53a. Here, even if a pulling force is applied to the rectangular electric conduit 61, the large diameter portion 63 abuts against the end plate 53a, so that the rectangular electric conduit 61 does not come out of the bent trough 1. Note that the number of electric conduits fixed to one end plate 53a is not necessarily one, and may be two or more.

[0091] Also, the conduit having independent waves is not limited to the rectangular conduit 61. Fig. 17(a) is a diagram showing a trough connection structure 50d in which a bent trough 1 and an independent wave conduit 61a are connected. The independent wave conduit 61a is similar to the rectangular conduit 61 in that large diameter portions 63 and small diameter portions 65 are formed alternately, but the cross-sectional shape of the large diameter portion 63 is circular, not rectangular. That is, in the independent wave conduit 61a connected to the bent trough 1, both the large diameter portion 63 and the small diameter portion 65 have a circular cross-sectional shape.

[0092] The inner diameter of the substantially circular opening 55a formed in the end plate 53a is slightly larger than the outer diameter of the small diameter portion 65 of the independent wave conduit 61a and smaller than the outer diameter of the large diameter portion 63 of the independent wave conduit 61a. Therefore, as shown in Fig. 17(b), the small diameter portion 65 of the independent wave conduit 61a is sandwiched between the opening 55a of the end plate 53a, so that the independent wave conduit 61a is fixed to the end plate 53a. Even if a pulling force is applied to the independent wave conduit 61a, the large diameter portion 63 abuts against the end plate 53a, so that the independent wave conduit 61a does not come out of the bent trough 1. In this way, in the trough connection structures 50c, 50d, a rectangular conduit 61 or an independent wave conduit 61a is fixed to the opening 55a of the end plate 53a, and the end plate 53a is fixed to the female joint structure of the curved trough 1, thereby connecting the curved trough 1 and the conduit.

[0093] Next, a description will be given of another trough connection structure using the curved trough 1. Figures 18(a) to 18(c) are diagrams showing a method for fixing an inner connection member 57a and an outer connection member 57b to the end of a helical wave conduit 61b. In this embodiment, the conduit connected to the curved trough 1 is a helical wave conduit 61b having a helical wave structure with a circular cross section.

[0094] The inner connection member 57a has a cylindrical portion 67a with a circular cross section, the outer circumferential surface of which is formed a helical groove that can fit into the helical shape of the inner circumferential surface of the helical wave conduit 61b, and a flange portion 69a formed at the end of the cylindrical portion 67a and having an enlarged diameter. The outer connection member 57b has a cylindrical portion 67b with a circular cross section, the inner circumferential surface of which is formed a helical groove that can fit into the helical shape of the outer circumferential surface of the helical wave conduit 61b, and a flange portion 69b formed at the end of the cylindrical portion 67b and having an enlarged diameter.

[0095] First, as shown in FIG. 18(b), the outer connection member 57b is attached to the end of the helical wave conduit 61b. That is, the helical wave on the inner peripheral surface of the cylindrical portion 67b of the outer connection member 57b is screwed into the helical wave on the outer peripheral portion of the helical wave conduit 61b. Next, as shown in FIG. 18(c), the inner connection member 57a is attached to the end of the helical wave conduit 61b. That is, the helical wave on the outer peripheral surface of the cylindrical portion 67a of the inner connection member 57a is screwed into the helical wave on the inner peripheral portion of the helical wave conduit 61b. In this way, the cylindrical portions 67a and 67b of the inner connection member 57a and the outer connection member 57b are screwed into the inner peripheral surface and the outer peripheral surface of the helical wave conduit 61b, respectively, and the inner connection member 57a and the outer connection member 57b are attached to the end of the helical wave conduit 61b.

[0096] Here, the outer connection member 57b is disposed further from the end of the helical wave conduit 61b than the inner connection member 57a. A gap is formed between the flange portion 69b of the outer connection member 57b and the flange portion 69a of the inner connection member 57a. For example, when the cylindrical portion 67a of the inner connection member 57a is completely screwed into the inside of the helical wave conduit 61b, the size of the gap between the flange portion 69b of the outer connection member 57b and the flange portion 69a of the inner connection member 57a can be adjusted by rotating the cylindrical portion 67b of the outer connection member 57b on the outer circumference of the helical wave conduit 61b.

[0097] 19 is a diagram showing a connection structure (trough connection structure 50e) between the curved trough 1 and the helical wave conduit. An end plate 53a having an opening 55a through which the conduit can be inserted is disposed in the female joint structure 17a of the opening 9 of the curved trough 1. In this case, the inner diameter of the substantially circular opening 55a formed in the end plate 53a is slightly larger than the outer diameter of the helical wave conduit 61b and smaller than the outer diameters of the flange portion 69b of the outer connection member 57b and the flange portion 69a of the inner connection member 57a. Therefore, the end plate 53a is sandwiched between the flange portion 69a of the inner connection member 57a and the flange portion 69b of the outer connection member 57b, and the helical wave conduit 61b is fixed to the end plate 53a.

[0098] In this way, in the trough connection structure 50e, the inner connection member 57a and the outer connection member 57b are fixed to the end of the helical wave conduit 61b. Also, the helical wave conduit 61b is arranged in the opening 55a of the end plate 53a, and the end plate 53a is sandwiched between the flange portion 69a of the inner connection member 57a fixed to the helical wave conduit 61b and the flange portion 69b of the outer connection member 57b, and the helical wave conduit 61b is fixed to the end plate 53a. Therefore, even if a pulling force is applied to the end plate 53, the helical wave conduit 61b will not come out of the female joint structure 17a of the bent trough 1. Also, the end plate 53a is fixed to the female joint structure 17a of the bent trough 1, and thus the bent trough 1 and the helical wave conduit 61b are connected.

[0099] When the end plate 53a is used, an end plate 53b as shown in FIG. 20 may be used in place of the end plate 53a so as to be more reliably fixed to the female joint structure 17a.

[0100] End plate 53b has a structure similar to that of end plate 53a, but a protrusion 59 is formed at the bottom tip of lower end plate 53b. As described above, groove 23 having a predetermined length in the width direction of the trough is formed at approximately the center of the bottom surface of female joint structure 17a of curved trough 1. Protrusion 59 can be fitted into groove 23 formed in female joint structure 17a of curved trough 1.

[0101] In this way, by fitting the protrusions 59 of the end plate 53b into the grooves 23, the end plate 53b can be fixed to each trough more reliably, and for example, the end plate 53b can be prevented from rotating in an oblique direction. The same effect can be obtained by forming the protrusions 59 downward on the end plate 53 that opens upward.

[0102] As described above, by using the method of connecting the straight trough 41, the curved trough 1, the small diameter trough 47 and each electric conduit (which may be collectively referred to simply as cable protection members) to the curved trough 1, a connection structure between the curved trough 1 and various cable protection members can be obtained.

[0103] More specifically, at the ends of the opening 9 at both ends of the curved trough 1 and at a position near the end of the opening 9 and spaced a predetermined distance from the end of the opening 9, vertical ribs 15 of a predetermined height extend inwardly and perpendicularly from the side plate 7 so as to face each other, forming a pair of substantially U-shaped female joint structures 17a, 17b. In this case, in the female joint structure 17a, 17b formed in either of the curved troughs 1, the small diameter portion of the male joint structure of the trough can be fixed directly to the space formed by the vertical ribs 15, or the small diameter portion of the male joint structure of the trough can be fixed via an end plate, or the small diameter portion of an independent wave conduit having a circular or rectangular cross section or the end of a helical wave conduit can be fixed via an end plate to the space.

[0104] As described above, according to this embodiment, the back surface of the bottom plate 5 of the curved trough 1 is provided with the hollow columnar protrusion 27 that protrudes downward from the bottom surface and has a hollow interior, and can be used as a bolt fixing structure, so that the curved trough 1 can be fixed with the anchor bolt 35 not only to ordinary gravel surfaces and the ground, but also to road surfaces such as asphalt and concrete, and inclined surfaces. In addition, when fixing the curved trough 1 with the anchor bolt 35, the provision of the hollow columnar protrusion 27 makes it possible to avoid stress concentration on the bottom plate 5.

[0105] In addition, the hollow columnar protrusion 27 having a hollow interior is provided on the back surface of the bottom plate 5, thereby reinforcing the bottom plate 5. This allows the bottom plate 5 of the curved trough 1 to be made thinner, thereby achieving a reduction in the weight of the curved trough 1.

[0106] In this case, the presence of the thin bottom plate 5 on the upper portion of the hollow columnar protrusion 27 makes it possible to make the height of the curved trough 1 and the cable storage section of the other troughs connected to it approximately the same. For example, when taking into consideration the ability to pull in the cable, the bottom plate 5 can be provided at a position slightly higher than the ground surface 31. For this reason, when connecting the female joint structure of the curved trough 1 to the male joint structure of the other trough, the heights of the male joint structure of the other trough and the bottom plate of the trough body are usually set to a constant value, so that the height of the bottom plate of the curved trough and the height of the bottom plate of each trough can be made approximately the same, resulting in excellent cable pulling ability.

[0107] In addition, when the hollow columnar protrusion 27 is not used as a bolt fixing structure, by removing the shielding portion of the bottom plate 5 that shields the hollow portion on the surface of the bottom plate 5 on the base side of the hollow columnar protrusion 27 and forming a through hole, it can also be used as a drainage hole for the curved trough 1.

[0108] Furthermore, by providing protruding feet 25 on the back surface of curved trough 1, bottom plate 5 can be positioned at a predetermined height from ground surface 31. In this way, by having bottom plate 5 spaced a predetermined distance from ground surface 31, even if ground surface 31 is uneven, it is possible to avoid interference between the curved trough 1 and the unevenness of ground surface 31. In this way, a predetermined space is created between the back surface of bottom plate 5 and ground surface 31, so that it is less susceptible to the condition of ground surface 31 and can be fixed to road surfaces such as asphalt and concrete, as well as inclined surfaces.

[0109] In addition, the side plate 7 can be reinforced by providing the bent portion 11 to form a bent structure. In addition, by providing the horizontal rib 13 so as to connect the bent portion 11 of the side plate 7, both ends of the bent portion 11 can be supported by the horizontal rib 13, so that the bent portion 11 of the side plate 7 can be further reinforced by the horizontal rib 13. In addition, both ends of the bent portion 11 have the effect of reinforcing the side plate 7 as the vertical rib 15 perpendicular to the bending direction of the bent portion of the side plate 7 on the outer periphery of the curved trough 1. Therefore, even if the thickness of the side plate 7 is not so large, the structural strength can be maintained as a whole. Since the vertical rib of the bent portion 11 of the curved trough 1 also serves as the substantially parallel inner vertical rib 15 of the U-shaped shape of the female joint structures 17a and 17b, it is sufficient to provide only the outer vertical rib 15 of the female joint structures 17a and 17b, and it is not necessary to provide a vertical rib on the outside of the bent portion of the side plate 7.

[0110] Furthermore, by utilizing the horizontal rib 13 as a fixing part of a fixing bracket for fixing the trough lid 3 to the top of the curved trough 1, the trough lid 3 can be easily fixed when placing the trough lid 3 on the curved trough 1.

[0111] In addition, openings 9 are provided at both ends of the curved trough 1, and in the openings 9, a pair of mutually opposing, substantially parallel, U-shaped rib structures extending inward from the side plate 7 at a predetermined height are formed. Also, a similar female joint structure 17b is formed at a predetermined position in the middle of the curved part of the curved trough 1. Therefore, by cutting the curved trough 1 at a predetermined position, a curved trough having female joint structures 17a, 17b formed at both ends can be obtained. Such female joint structures 17a, 17b make it possible to connect to the male joint structures of other troughs or to the female joint structures of other straight troughs, curved troughs, etc. via the male-male conversion connection adapter 51, and a trough line in which a cable is laid inside the various troughs connected to each other can be formed.

[0112] Moreover, the female joint structures 17a, 17b are configured to include the mutually opposing side plates 7, and two parallel vertical ribs 15 sandwiching the side plates 7, and connecting the two. The bent portion 11 also serves as the inner vertical rib 15 of the pair of female joint structures 17a, 17b having a substantially U-shape in plan view, and therefore not only serves as the vertical rib 15 as the reinforcing structure described above, but also serves as the vertical rib 15 forming the mating portion of the female joint structures 17a, 17b. Therefore, there is no need to provide a new vertical rib, such as the outer vertical rib 15 of the female joint structures 17a, 17b.

[0113] Furthermore, by providing the female joint structures 17a, 17b with end plates 53, etc., it is possible to form a connection structure in which various conduits, such as not only a normal straight trough 41 but also a small-diameter trough 47 having a small cross-sectional dimension, a rectangular conduit 61 having an independent wave structure, an independent wave conduit 61a, and a helical wave conduit 61b having a helical wave structure, are connected to the curved trough 1 via the end plates 53, etc. In this case, the female joint structures 17a, 17b need to have dimensions and shapes that can accommodate all connection structures so that the connection can be stably made to the trough of the connection partner, the small diameter portion of the conduit, etc.

[0114] Furthermore, a shallow groove 23 having a predetermined length in the width direction of the curved trough 1 is formed in the approximate center of the bottom of a pair of mutually opposing, approximately U-shaped female joint structures 17a, thereby making it possible to efficiently fix the end plate 53b having the protrusion 59 and simultaneously prevent the end plate 53b from rotating in an oblique direction. In this way, by providing the groove 23 in the bottom plate 5 of the female joint structure 17a and using the end plate 53b, it is possible to use it for fixing structures such as various troughs and electric conduits, in addition to connection structures using normal female joint structures 17a.

[0115] Although the embodiment of the present invention has been described above with reference to the attached drawings, the technical scope of the present invention is not limited to the above-described embodiment. It is clear that a person skilled in the art can think of various modifications or alterations within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0116] 1....Bent trough 3...Trough cover 5……Bottom plate 7...Side panel 9...Opening 11....Bending section 13...Horizontal rib 15………Vertical rib 17a, 17b...Female joint structure 19………Inner bend 21....Outer bend 23……groove 25……Foot part 27……Hollow columnar protrusion 29………Bottom reinforcement rib 31...Ground surface 33……Space 35………Anchor bolt 40………Bent trough fixing structure 41: Straight trough 43, 43a………Male joint structure 45, 45a…Female joint structure 47………Small diameter trough 50, 50a, 50b, 50c, 50d, 50e... Trough connection structure 51………Male / Male conversion connection adapter 53, 53a, 53b……End plate 55, 55a……Opening 57a...Inner connecting member 57b....Outer connecting member 59……Protrusion 61……Square conduit 61a……Independent wave conduit 61b………Spiral wave conduit 63...Large diameter section 65……Small diameter part 67a, 67b... Cylindrical portion 69a, 69b...Flange portion

Claims

1. A curved trough having a U-shaped cross section, the trough including side plates forming both side surfaces and a bottom plate forming a bottom surface, the side plates standing up to surround the bottom plate, The bottom plate has a curved portion at a predetermined angle in a predetermined direction in a plan view, and the side plate on both sides of the side plate forming the inner curved portion and the side plate forming the outer curved portion rise upward so as to surround the curved portion of the bottom plate, the side plate forms a substantially arcuate curved portion that forms the outer curved portion and the inner curved portion, A generally U-shaped opening is formed at each end of the side plate, At the ends of the openings at both ends of the side plates and in the vicinity of the ends of the openings at both ends, substantially parallel vertical ribs are formed at both sides of the curved portion of each of the side plates, extending inward in a direction perpendicular to the curved portion and spaced apart by a predetermined distance from each other, thereby forming a pair of substantially U-shaped female joint structures facing each other in a plan view having the vertical ribs, Another female joint structure similar to the openings at both ends of the side plate is formed at a predetermined position in the middle of the bent portion that is a predetermined distance away from one end of the bent portion and in the vicinity of the predetermined position in the middle of the bent portion, The side plates of the inner curved portion and the outer curved portion are formed with bent portions, each of which functions as a vertical rib protruding inward, at a predetermined position near the opening and at a predetermined position intermediate the bent portion, the bent portions being spaced apart by a predetermined distance, The bent portion provided at a predetermined position near the opening also serves as an inner vertical rib of the female joint structure near the opening, and the bent portion formed at a predetermined position in the middle of the bent portion also serves as an inner vertical rib of the other female joint structure, A horizontal rib is formed on the upper portion of the bent portion, which also serves as a vertical rib, at a predetermined distance from each other at a predetermined position near the opening of the side plate and at a predetermined position between the bent portion and the side plate, to which a fixing metal fitting for attaching a lid can be attached so as to connect the vertical ribs to each other; A curved trough, characterized in that the transverse ribs of the outer curved portion are longer than the transverse ribs of the inner curved portion, and no longitudinal ribs are provided on the outside of each of the side plates forming the inner curved portion and the outer curved portion.

2. The bottom plate surfaces of the female joint structures formed at both ends of the bent portion are formed to be lower by a predetermined height than the bottom plate surfaces of the portions other than the female joint structure, The foot portion of the side plate of the female joint structure is formed to protrude from the back surface of the bottom plate at a predetermined height, and the bottom plate is supported by the foot portion at a predetermined height above the ground surface, thereby forming a space on the back surface of the bottom plate, a hollow columnar protrusion protruding downward from the bottom plate by a predetermined height is formed at a predetermined position of the space created by the inner curved portion and the outer curved portion formed on the back surface of the bottom plate; The curved trough according to claim 1, characterized in that the top surface of the hollow columnar protrusion is either closed by the bottom plate or the top surface of the hollow columnar protrusion is open, and the hollow columnar protrusion is formed as at least one anchor bolt fixing portion.

3. A bottom reinforcing rib is formed on the back surface of the bottom plate, the bottom reinforcing rib connecting the inner curved portion and the outer curved portion, 3. The curved trough according to claim 2, wherein the bottom reinforcing rib is formed at a different position apart from the hollow columnar protrusion in a direction toward the center of curvature of the inner curved portion and the outer curved portion.

4. A bottom reinforcing rib is formed on the back surface of the bottom plate, the bottom reinforcing rib connecting the inner curved portion and the outer curved portion, The curved trough according to claim 2, characterized in that the bottom reinforcing rib is formed so as to sandwich the hollow columnar protrusion on the same straight line including the hollow columnar protrusion in a direction toward the center of curvature of the inner curved portion and the outer curved portion.

5. The outer longitudinal ribs of the other female joint structure formed at a predetermined position between one end of the bent portion formed at both ends of the trough and the other end spaced a predetermined distance from the other end and at a predetermined position in the vicinity of the other female joint structure are formed substantially parallel to each other at a predetermined height in a direction perpendicular to the bottom plate so as to extend inward from the side plate, The curved trough according to claim 1, characterized in that it is provided with a curved trough structure having a bending angle smaller than the bending angle before cutting, which can be obtained when cutting along the longitudinal rib so as to connect the outer surfaces of the longitudinal rib formed perpendicular to the curve forming the bent portion.

6. A curved trough as described in claim 5, characterized in that when the angle of the curved portion connecting the openings at both ends of the curved trough before cutting is 90°, the angle of the curved portion after cutting is 60°, when the angle of the curved portion connecting the openings at both ends before cutting is 60°, the angle of the curved portion after cutting is 45°, and when the angle of the curved portion connecting the openings at both ends before cutting is 45°, the angle of the curved portion after cutting is 30°.

7. The connection structure of the curved trough and the straight trough according to claim 1, A connection structure for a curved trough, characterized in that a male joint structure of a straight trough of a predetermined length and having cross-sectional dimensions of the curved trough and the trough body substantially the same is connected to the female joint structure of the opening at either end of the curved trough.

8. The connection structure of the curved trough and the straight trough according to claim 1, A connection structure for a curved trough, characterized in that a female joint structure of a straight trough of a predetermined length, in which the cross-sectional dimensions of the curved trough and the trough body are approximately the same, is connected to the female joint structure of the opening at either end of the curved trough via a male-male conversion connection adapter.

9. The connection structure of the curved trough and the small diameter trough according to claim 1, A rectangular end plate having a width greater than the distance between the opposing longitudinal ribs of the female joint structure is inserted into the female joint structure of the opening at either end of the curved trough, The end plate is approximately U-shaped with an opening of a predetermined size formed either at the bottom or top, and a male joint structure of a small diameter trough is placed in the opening of the end plate, and a flange portion of the male joint structure of the small diameter trough is fitted into the opening of the end plate as a non-slip structure to connect the male joint structure of the small diameter trough to the end plate, thereby fixing the male joint structure of the small diameter trough to the end plate.

10. The connection structure of the bent trough and the electric conduit according to claim 1, The conduit connected to the bent trough has an independent wave structure, and the conduit is either an independent wave conduit having a small diameter portion with a circular cross section, or a rectangular conduit in which a large diameter portion with a rectangular cross section and a small diameter portion with a circular cross section are alternately formed, An end plate having a half structure and capable of being separated into upper and lower parts is disposed in the female joint structure of any one of the openings of the curved trough, The end plate has an opening at an opposing portion when divided, and the small diameter portion of the electric conduit is clamped in the opening of the end plate, thereby fixing the electric conduit to the end plate.

11. The connection structure of the bent trough and the electric conduit according to claim 1, The electric conduit connected to the bent trough is a helical wave electric conduit having a helical wave structure with a circular cross section, an inner connection member including a cylindrical portion having a circular cross section and a spiral groove that can be fitted to an inner peripheral surface of the electric conduit, and a flange portion formed at an end of the cylindrical portion; an outer connection member having a cylindrical portion with a circular cross section having a spiral groove that can be fitted to an outer peripheral surface of the electric conduit, and a flange portion formed at an end of the cylindrical portion; the cylindrical portions of the inner connection member and the outer connection member are screwed to an inner peripheral surface and an outer peripheral surface of the electric conduit, respectively, and are attached to an end portion of the electric conduit; a connecting structure for a curved trough, characterized in that the outer connecting member is positioned further back from the end of the electric conduit than the inner connecting member, an end plate having an opening through which the electric conduit can be inserted is positioned in the female joint structure of the opening, and the electric conduit is fixed by sandwiching the end plate between a flange portion of the inner connecting member and a flange portion of the outer connecting member.

12. A connection structure for a curved trough as described in any one of claims 9 to 11, characterized in that a groove having a predetermined length in the width direction of the trough is formed at approximately the center of the surface of the bottom plate, which is the bottom of a pair of mutually opposing, approximately C-shaped female joint structures, and a protrusion that can fit into the groove is provided at the bottom tip of the end plate.

13. The fixing structure of the curved trough according to claim 2, The hollow columnar protruding portion protruding downward from the back surface of the bottom plate at a predetermined height is formed as an anchor bolt fixing portion, The hollow columnar protrusion has a hollow cylindrical structure, and an anchor bolt is inserted into the hollow portion of the hollow cylindrical structure and tightened to fix the curved trough to asphalt or concrete ground.

14. A method for connecting a cable protection member to the bent trough according to claim 1, comprising the steps of: In the female joint structure, the vertical ribs having a predetermined height are formed so as to extend inwardly and perpendicularly from the side plates so as to face each other in a substantially parallel manner at the ends of the opening at both ends of the curved trough and at positions near the ends of the opening and spaced a predetermined distance from the ends of the opening, A method for connecting a cable protection member to a curved trough, characterized in that a small diameter portion of the male joint structure of the trough is fixed directly to a space formed by the vertical ribs, or the small diameter portion of the male joint structure of the trough is fixed via an end plate, or the small diameter portion of an independent wave conduit having a circular or rectangular cross section or the end of a helical wave conduit is fixed via an end plate.

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