Branching trough, bent trough, branching trough connection structure, trough line, branching trough fixing structure, bent trough fixing structure, and method for connecting cable protection member to branching trough

Abstract

A branching trough 1 is mainly comprises side plates 7 forming both side surfaces, and a bottom plate 5 constituting a bottom surface, wherein both side plates 7 are erected so as to surround the bottom plate 5. A cross section of the branching trough 1 is substantially U-shaped, and the branching trough 1 is substantially T-shaped in plan view. A female joining structure 23a for connecting a cable protection member is formed in openings 15a at both longitudinal-direction ends of a main trunk section 9. Similarly, a female joining structure 23b for connecting the cable protection member is formed in an opening 15b at the leading end of a branch section 11. A vertical rib 21 of an elbow section 17 of the side plates 7 can also serve as a vertical rib inside the female joining structure 23a. On the back surfaces of the main trunk section 9 and branch section 11, a hollow columnar protrusion 27 protruding downward to a prescribed height from the bottom plate 5 is formed at a prescribed position of the space described above. This present invention also includes a bent trough 41 having a similar hollow columnar protrusion 67 and female joining structure 57a in which an elbow section 51 of a side plate 47 also serves as a vertical rib 55 inside the female joining structure.

Description

Branch trough, curved trough, connection structure for branch trough, trough line, fixing structure for branch trough, fixing structure for curved trough, and method for connecting cable protection member to branch trough

[0001] The present invention relates to a branching trough and a bent trough having an approximately T-shape in which a cable is laid inside, a connection structure for a branching trough using these, a trough line, a fixing structure for a branching trough, a fixing structure for a bent trough, and a method for connecting a cable protection member to a branching trough.

[0002] In recent years, various structures have been proposed for laying cables used for transporting electric power, etc. For example, a trough line has been proposed in which a resin trough is installed and a cable is laid inside the trough.

[0003] As an example of a trough used in such a trough line, a trough for laying branch cables has been proposed, which includes a trough body having a notch on the side and a branch trough whose one end is joined to correspond to the notch (Patent Document 1). The trough in Patent Document 1 has a long groove formed 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.

[0004] Also, a trough for laying branch cables has been proposed, characterized in that it is formed by integrally molding a trough body having an opening on the side and a branch trough having one end facing the opening and joined thereto (Patent Document 2). Unlike the trough of Patent Document 1, the trough of Patent Document 2 is not a structure in which each part is divided, but is formed as a single unit.

[0005] In addition, a trough has been proposed that allows the bottom plate and side surfaces of a U-shaped gutter to be easily assembled on-site using corner members, thereby reducing the volume during storage (Patent Document 3). The trough in Patent Document 3 achieves weight reduction by using plastic materials, and branching is made easier by providing holes in the side walls. Furthermore, using recycled materials for some or all of the plastic material can suppress increases in cost.

[0006] Also, a cable trough has been proposed in which concave connection portions are formed at both ends of the body of a directional trough, and the concave connection portions of adjacent troughs are connected by a U-shaped connecting member (Patent Document 4). The trough of Patent Document 4 can be bent to either the left or right side or branched by flipping the base end and tip end of the body over. This eliminates the need to prepare two types of troughs, one for right-side bending (for right-side branching) and one for left-side bending (for left-side branching).

[0007] Also, a trough connection component has been proposed that can insert and connect a substantially cylindrical cable protection material that accommodates and protects various cables (Patent Document 5). In Patent Document 5, the main body of the trough connection component, which is a cable protection material connection component placed at the connection portion of the cable protection material, is formed into a hollow box shape by combining a synthetic resin body and an upper cover. In addition, inner and outer ribs that serve as cutting guidelines are provided on the side wall surface of the trough connection component main body, and an opening corresponding to the cable protection material to be connected is cut along the inner and outer ribs. The cable protection material can be inserted into this opening for connection.

[0008] Also, a curved trough with male joint structures at both ends has been proposed (Patent Document 6). The curved trough of Patent Document 6 can be connected to other troughs by fitting the male joint structure at one end with a female joint structure provided at the end of another trough.

[0009] Japanese Utility Model Application Publication No. 61-98328 Japanese Utility Model Application Publication No. 61-982329 JP 2005-245186 A Japanese Utility Model Application Publication No. 6-5334 Japanese Utility Model Application Publication No. 6-024321 US 2020 / 0277739 A1

[0010] However, Patent Documents 1 to 6 do not disclose that the upper part of the bent section has a horizontal rib connecting both sides of the bent section, and that the opposing bent sections also have a structure that doubles as vertical ribs, and that the horizontal ribs are provided at the upper part of the bent section to reinforce it, while the horizontal ribs are provided as trough fixing bracket attachment parts. Furthermore, there is no disclosure that the bent section also doubles as the inner vertical rib of the female joint structure. Furthermore, none of the troughs has a structure for fixing the trough to the installation ground.

[0011] Furthermore, in order to stably fix a conventional trough to, for example, a slope, it is necessary to drill holes directly into the bottom of the trough and fasten the bottom plate with bolts. However, drilling holes in the bottom plate of the trough and fastening it with bolts can cause cracks or deformation in the bottom of the trough. This has led to problems such as the difficulty of stably fixing the trough to a slope.

[0012] Typically, linear troughs often have external ribs on the outer surfaces of the trough side plates for reinforcement. This is done to ensure strength while taking advantage of the thin, lightweight characteristics of plastic troughs. However, when external ribs are provided on the protruding portions of branch troughs or the side plates of curved troughs, the protruding rib structure has a greater impact on the exterior than in linear troughs, potentially damaging the ribs during work or causing workers to trip over them. Furthermore, when flying objects from natural disasters such as typhoons hit the ribs, the risk of rib damage increases compared to linear troughs, as flying objects are more likely to hit the ribs and the energy of the collision is more likely to concentrate on the ribs. In this regard, there has been a need for a simple, thin, lightweight branch trough or curved trough with no protruding ribs beyond the contour lines connecting the curved portions of the side plates, which can be stably fixed to unstable ground surfaces and has excellent connectivity as a connecting member. However, such troughs do not exist.

[0013] A first feature of the present invention is to provide a branched trough or a curved trough having a trough side plate with a bent portion having vertical ribs formed at a predetermined distance from each other, and horizontal ribs formed at the top of the bent portion of the side plate connecting the vertical ribs formed at the predetermined distance from each other at the bent portion, thereby forming a reinforcing structure for the trough side plate and also serving as a fastener attachment portion for attaching fasteners. As a result, the structural strength of the trough can be ensured without providing vertical ribs on the outer side of the side plate at the bent portion of the branched trough or curved trough, eliminating the need to provide vertical ribs on the outer side of the bent portion of the side plate. Furthermore, the vertical rib of the bent portion formed near the trough opening is formed to also serve as the inner vertical rib of the female joint structure, thereby not only increasing the structural strength of the trough side plate but also simplifying the structure of the branched trough or curved trough.

[0014] The present invention has a second feature in addition to the first feature. The second feature of the present invention aims to provide a branch trough, curved trough, or the like that has excellent installability and includes hollow columnar protrusions as bolt-fixing rib structures that allow easy fixation to the ground with anchor bolts, even when the installation ground is sloped. With this structure, even when the bottom plate is bolted, the bolt tightening load is supported by the hollow columnar protrusions formed on the back surface of the trough bottom plate, allowing for fixation without deformation or cracking of the bottom plate even when the bottom plate is thin. Furthermore, since space can be secured on the back surface of the bottom plate, the trough can be fixed even if there are some obstacles or unevenness in the ground, or the ground is on a slope. Furthermore, the thinning of the bottom plate allows for weight reduction and makes it easier to stably hold the cable on the trough, including the trough connection section.

[0015] In addition to the first and second features, the present invention has a third feature. The third feature is that by attaching a male-female conversion connection adapter or end plate to the female part of the branch trough, connection structures with a variety of troughs and electrical conduits can be obtained. Specifically, this allows for a variety of connection structures to be obtained with straight troughs of the same structure, bent troughs, small-diameter troughs, circular cross-sectional independent corrugated electrical conduits, rectangular cross-sectional rectangular electrical conduits, circular cross-sectional helical corrugated electrical conduits, etc.

[0016] Furthermore, by using the connection structure of the third characteristic, it is possible to obtain inventions such as a trough line in which a plurality of linear troughs of a predetermined length are connected to a branch trough, or a trough line in which a curved trough or a shielding plate is connected to the branch trough. Furthermore, by fixing the hollow columnar protrusions of the branch trough or curved trough with anchor bolts, it is possible to obtain a fixing structure for these troughs to asphalt or concrete ground. Finally, it is also possible to obtain inventions of connection methods for obtaining various connection structures for cable protection members to the branch troughs.

[0017] In order to achieve the above-mentioned object, the first invention provides a branching trough having a U-shaped cross section, comprising side plates forming both side surfaces and a bottom plate forming the bottom surface, with both side plates standing up to surround the bottom plate, wherein the bottom plate is approximately T-shaped in plan view and is composed of a substantially rectangular main trunk and a branch section formed on one long side of the main trunk in a direction perpendicular to the longitudinal direction of the main trunk, the branch section gradually reducing in diameter in a substantially arc-like shape, the side plate being formed by a straight section formed on one long side of the main trunk and a curved section forming the outer edge of the branch section extending and reducing in diameter in a substantially arc-like shape, and wherein the opening at the tip of the branch section and the opening at both longitudinal ends of the main trunk are each formed with a female joint structure of similar structure, and the female joint structures are each formed as a pair of approximately U-shapes facing each other in plan view, with substantially parallel vertical ribs spaced a predetermined distance from each other, This branching trough is characterized in that a horizontal rib is formed at the top of the bent portion of the side plate, which also serves as a fixing bracket mounting portion for attaching a fixing bracket for attaching a lid, connecting the vertical ribs of each of the bent portions, which are formed at a predetermined distance from each other, and no vertical rib is provided on the outside of the side plate of the approximately arc-shaped bent portion.

[0018] Furthermore, the branching trough of the present invention may be such that the female joint structures formed at the openings at both ends of the main trunk are female joint structures formed so as to extend inward in a direction perpendicular to the straight portion of the side plate of the main trunk and the side plate of the curved portion, and the female joint structure formed at the opening at the tip of the branching portion is a female joint structure formed so as to extend inward in a direction perpendicular to the curved portion, and the bending portions formed in the main trunk and the branching portion are all formed so as to double as inner vertical ribs of the respective female joint structures provided at the ends of the openings of the main trunk and the branching portion.

[0019] In the branch trough of the present invention, the female joint structures formed at both longitudinal ends of the main trunk are such that one approximately U-shaped structure is provided at the end of the straight section, and the other approximately U-shaped structure is provided at the end of the curved section connected to the branch section. However, since both are formed in a substantially rectangular region of the main trunk, the pair of approximately U-shaped structures formed at the ends of the straight section and the curved section, respectively, are considered to be the female joint structures of the main trunk. In contrast, the female joint structure formed at the opening at the tip of the branch section is considered to be the female joint structure on the branch section side. Furthermore, in the branch trough of the present invention, the bent section is formed by bending both sides of the side plate at a predetermined position on the straight section of the main trunk or the curved section connected to the branch section so that it protrudes inward. In this case, the bent section refers to the bent section on one side, not the entire inward-protruding section including both bent sections.

[0020] The branch trough may be characterized in that the bottom plate surface of the female joint structure is formed at a predetermined height lower than the bottom plate surfaces of parts other than the female joint structure, the foot portions of the side plates of the female joint structure are formed to protrude from the back surface of the bottom plate at a predetermined height, and the bottom plate is supported by the foot portions at a predetermined height above the ground surface, thereby forming a space on the back surface of the bottom plate, a hollow columnar protrusion is formed at a predetermined position in the space formed on the back surface of the main trunk part and the branch part, protruding downward from the bottom plate at a predetermined height, 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 part.

[0021] On the back surface of the bottom plate of the branching trough, which has an approximately T-shape, multiple bottom reinforcing ribs of a predetermined length may be formed parallel to each other, connecting the two from positions each shifted a predetermined distance from the longitudinal center of the straight side plate of the main trunk portion toward the opening of the branching portion that extends opposite it.

[0022] According to the first aspect of the present invention, the female joint structure of the opening of the branch trough is configured such that ribs extending inward are formed on both sides of the side plate at the opening edge of the side plate and at a predetermined distance from the opening edge, and the vertical ribs on both sides of the side plate are formed so as to face each other. In this way, the female joint structure formed at the opening is a rib structure, which has the effect of reinforcing the end of the branch part of the side plate.

[0023] In addition, the side plates are formed with bent portions, and the bent portions and horizontal ribs arranged therein can increase the bending and compressive strength of the side plates. Furthermore, the bent portions also serve as vertical ribs, thereby enhancing the reinforcing effect of the vertical ribs formed at the ends of each opening. Furthermore, the vertical ribs forming the bent portions formed near the ends of the main trunk and branch portions also serve as the approximately parallel inner vertical ribs of the female joint structure formed at each opening. Therefore, it is possible to form only the outer vertical ribs without forming other inner vertical ribs, simplifying the structure of the branch trough. At the same time, because the upper parts of the vertical ribs are supported by the horizontal ribs, these vertical ribs have the effect of reinforcing the female joint structure.

[0024] Furthermore, the vertical ribs on the inside of the side panels formed at and near both ends of the bent section, and the horizontal ribs connecting the vertical ribs, both have the effect of reinforcing the side panels at the bent section. The bent section of the side panels, the horizontal ribs, and the vertical ribs are integrally formed with the horizontal ribs sandwiched between them, resulting in multiple reinforcing effects. The horizontal ribs not only reinforce the vertical ribs, but can also be used as mounting points for fastening metal fittings to secure the trough lid.

[0025] The fixing bracket mounting portions are formed between the bent portions formed near both ends of the main trunk at a predetermined distance from each other and the outer ribs formed near the bent portions, and are also formed to connect the bent portions extending in a generally arc-shaped manner with a reduced diameter on both sides of the branch portion at a predetermined distance from each other. In this case, only two fixing brackets for securing the trough lid may be attached at diagonal positions on the main trunk side and the branch portion side, or a total of four fixing brackets may be attached around the entire circumference, two on the main trunk side and two on the branch portion side. Furthermore, bolt mounting holes are provided in the fixing bracket mounting portions, so the trough lid can be secured with bolts.

[0026] Furthermore, a hollow columnar protrusion that protrudes downward from the bottom surface may be provided on the back surface of the bottom plate of the branch trough. The hollow columnar protrusion functions as a bolt fixing structure, so that anchor bolts can be fixed to the bolt fixing structure on not only ordinary gravel surfaces and the ground, but also road surfaces such as asphalt and concrete, and inclined surfaces, making installation possible regardless of the ground conditions at the installation location.

[0027] Furthermore, forming hollow columnar protrusions in the branch troughs has the effect of reinforcing the thin bottom plate, and even if holes are drilled in the thin bottom plate, the branch troughs are supported by the hollow columnar protrusions, so microcracks do not occur in the holes in the bottom plate. Furthermore, since the load caused by tightening the anchor bolts when they are fixed is supported by the hollow columnar protrusions, deformation of the bottom plate and the occurrence of microcracks can be prevented compared to when anchor bolt fixing holes are provided directly in the bottom plate. Furthermore, since the thin bottom plate is located above the hollow columnar protrusions and the interior of the columnar protrusions is hollow, drilling holes in the bottom plate is easy, and it is possible to make the height of the cable storage sections of the other troughs connected to the branch trough approximately the same.

[0028] In this case, the bottom plate surface of the female joint structure formed in the branching trough may be formed a predetermined height lower than the bottom plate surfaces of the portions other than the female joint structure. By doing so, when the male joint structure of another trough is overlapped and connected to the female joint structure of the branching trough, the level of the upper surface of the cable storage section at the bottom of the branching trough can be aligned with the height of the bottom and cable storage section of the male joint structure of the other trough. As a result, the cable is arranged approximately horizontally in the trough, preventing excessive tension from being applied to the cable due to an oblique arrangement.

[0029] Alternatively, the side plates may protrude from the underside of the bottom plate at a predetermined height to form feet, and the feet may support the bottom plate at a predetermined height above the ground surface. In this case, a space can be formed on the underside of the bottom plate. For example, the bottom plate can usually be lowered when no ground preparation is required. However, if the ground is uneven, lowering the bottom plate can interfere with the bottom surface of the branch trough, causing installation problems. However, because the bottom plate is elevated from the ground by a predetermined height, the influence of ground unevenness can be reduced when installing the branch trough. This eliminates or minimizes the need for ground leveling and compaction work, improving installation ease. Furthermore, because the bottom plate is installed slightly higher than the ground, it is easy to install cables when connecting to other troughs, etc.

[0030] Furthermore, by forming a bottom surface reinforcing rib on the rear surface of the bottom plate at a position spaced a predetermined distance from the hollow columnar protrusion, the bottom plate can be reinforced more efficiently.

[0031] A second invention is a curved trough having a U-shaped cross section, comprising side plates forming both side surfaces and a bottom plate forming a bottom surface, with both side plates standing up to surround the bottom plate, wherein the bottom plate has a curved portion in a predetermined direction at a predetermined angle in a plan view, and the side plate forming the inner curved portion and the side plate on both sides of the side plate forming the outer curved portion stand up to form curved portions in a substantially arc shape facing upward so as to surround the curved portion of the bottom plate, and a substantially U-shaped opening is formed at each end of the side plate, and approximately parallel vertical ribs spaced apart by a predetermined distance are formed at the ends of the openings at both ends of the side plates and near the ends of the openings at both ends of the side plates, extending inward in a direction perpendicular to the curved portions, on both sides of the curved portions of each of the side plates, thereby forming a pair of substantially U-shaped female joint structures having the vertical ribs and facing each other in a plan view, The side plates of the inner bending portion and the outer bending portion are formed with bent portions that also serve as inwardly protruding vertical ribs, spaced a predetermined distance from each other, at a predetermined position near the opening and a predetermined position intermediate the bending portions, and horizontal ribs are formed at the top of the bent portions that also serve as vertical ribs, formed a predetermined distance apart at a predetermined position intermediate the bending portions and near the opening of the side plates, to which a fixing bracket for attaching a lid can be attached, so as to connect the vertical ribs together; the horizontal ribs of the outer bending portion are longer than the horizontal ribs of the inner bending portion, and the bending trough may have no vertical ribs on the outside of each of the side plates that form the inner bending portion and the outer bending portion.

[0032] Furthermore, the curved trough of the present invention may be such that another female coupling structure similar to the openings at both ends of the side plate is formed at a predetermined position in the middle of the curved portion a predetermined distance from one end of the curved portion and near the predetermined position in the middle of the curved portion, and the bent portion provided at the predetermined position near the opening also serves as an inner vertical rib of the female coupling structure near the opening, and the bent portion formed at the predetermined position in the middle of the curved portion also serves as an inner vertical rib of the another female coupling structure.Furthermore, the curved trough may be such 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 of the female coupling structures that are approximately U-shaped and facing each other in a plan view.

[0033] In addition, in the present invention, the bent portion is formed by bending the inner bent portion and the outer bent portion at a predetermined position on each curved portion to protrude inward. In this case, the bent portion does not refer to the entire inward protruding portion including the bent portions on both sides, but refers to the bent portion on one side of each.

[0034] the bottom plate surface of the female joint structure formed at least at both ends of the bent portion is formed to be lower by a predetermined height than the bottom plate surface of portions other than the female joint structure; foot portions of the side plates of the female joint structure are formed to protrude at a predetermined height from the back surface of the bottom plate, and the bottom plate is supported by the foot portions at a predetermined height above the ground surface, thereby forming a space on the back surface of the bottom plate; a hollow columnar protrusion is formed at a predetermined position in the space created by the inner bent portion and the outer bent portion formed on the back surface of the bottom plate, the hollow columnar protrusion protruding downward from the bottom plate at a predetermined height; the top surface of the hollow columnar protrusion is closed by the bottom plate or the top surface of the hollow columnar protrusion is open; and at least one hollow columnar protrusion is formed as an anchor bolt fixing portion; and the curved trough may be 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 of the female joint structures which are approximately U-shaped and facing each other in a plan view.

[0035] The other female coupling structure is formed at a predetermined position midway 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 thereof, and the outer longitudinal ribs of the other female coupling 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, and a curved trough structure having a bending angle smaller than the bending angle before cutting can be obtained by cutting along the longitudinal ribs so as to connect the outer surfaces of the inner bent portion and the longitudinal ribs of the outer bent portion, which are formed so as to be perpendicular to the curve that forms the bending portion. Therefore, the built-in curved trough can be cut out as needed.

[0036] According to the second invention, as with the first invention, the female joint structure at the opening of the curved trough is configured such that ribs extending inwardly and approximately parallel to each other are formed on both sides of the side plate at the opening end and a predetermined distance from the opening end, forming a pair of approximately U-shaped female joint structures with the longitudinal ribs on both sides of the side plate facing each other. Because the female joint structure formed at the opening is a rib structure, it is possible to reinforce the end of the side plate. Furthermore, because the same female joint structure is formed on both ends of the curved portion, the curved portion can be used whether the curved portion is bent leftward or rightward. On the other hand, if the joint structures at both ends are not the same, such as one being a female joint structure and the other being a male joint structure, the connecting joint structure will differ depending on the bending direction, and therefore cannot necessarily be used in the same way.

[0037] In addition, the side panels have bent sections, and the bent sections and horizontal ribs placed therein enhance the bending and compressive strength of the side panels. Furthermore, the vertical ribs on the inside of the side panels, which are formed at both ends of the bent section and at predetermined positions midway between the bent sections, and the horizontal ribs connecting the vertical ribs, both have the effect of reinforcing the side panels at the bent sections. In this way, the bent sections of the side panels, the horizontal ribs, and the vertical ribs are integrally formed with the horizontal ribs in between, resulting in a multiplicity of reinforcing effects.

[0038] Furthermore, the vertical ribs formed in the bent portion also serve as the generally parallel inner vertical ribs of the female coupling structure formed in each opening or at a predetermined position midway between the bent portion. This simplifies the structure of the branch trough, since it is only necessary to form the generally parallel vertical ribs of the generally U-shaped female coupling structure at the opening or bent portion. Furthermore, the upper portions of the vertical ribs are supported by the horizontal ribs, which reinforces the female coupling structure. Furthermore, there is no need to provide reinforcing vertical ribs on the outsides of the two side plates at the inner and outer bent portions. Furthermore, the horizontal ribs reinforce the vertical ribs and can also be used as mounting points for fastening fittings to secure the trough lid.

[0039] The fixing bracket mounting portions are provided at the approximate centers of the horizontal ribs provided at the opposing bent portions of the two side plates of the inner and outer bent portions, so that they face each other and share a center line as the center of curvature, and fixing brackets can be attached. Also, the fixing bracket mounting portions are provided with bolt mounting holes, so that the trough lid can be fixed with bolts.

[0040] The bottom plate of the curved trough may also be provided on its underside with a hollow columnar protrusion that protrudes downward from the bottom surface. The hollow columnar protrusion functions as a bolt fixing structure, allowing anchor bolts to be fixed to the hollow columnar protrusion on not only ordinary gravel surfaces and the ground, but also road surfaces such as asphalt and concrete, and inclined surfaces, making installation possible regardless of the ground conditions at the installation location.

[0041] In this case, 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 a predetermined height lower than the bottom plate surfaces of the male joint structure and the trough storage portion, which are parts other than the female joint structure.

[0042] By doing this, even in the case of a normal curved trough or a curved trough with a small cut bend, when the female joint structure of the curved trough is overlapped and connected to the male joint structure of another trough, the height can be adjusted to match the level of the top surface of the bottom of the curved trough with the height of the male joint structure and cable storage section of the other trough that is connected, and as a result, the cable is positioned approximately horizontally within the trough, preventing the cable from being positioned at an angle and causing excessive tension to be applied to the cable.

[0043] Furthermore, forming the hollow columnar protrusion has the effect of reinforcing the thin bottom plate, and even if holes are drilled in the thin bottom plate, microcracks do not occur in the drilled holes in the bottom plate. Furthermore, since the load caused by bolt tightening when the anchor bolts are fixed is borne by the hollow columnar protrusion, deformation of the bottom plate and the occurrence of microcracks can be prevented compared to when anchor bolt fixing holes are provided directly in the bottom plate. Furthermore, since the thin bottom plate is located above the hollow columnar protrusion and the interior of the columnar protrusion is hollow, drilling holes in the bottom plate is easy, and it is possible to make the height of the cable storage section of the branching trough and the other troughs connected to it approximately the same. This prevents excess tension from acting on the cables placed in the bent trough and the other troughs.

[0044] Furthermore, the side plates protrude from the underside of the bottom plate at a predetermined height, forming feet that support the bottom plate at a predetermined height above the ground surface. This allows for the creation of a space behind the bottom plate. For example, the bottom plate can usually be lowered when no ground preparation is required. However, if the ground is uneven, lowering the bottom plate can interfere with the bottom surface of the curved trough, causing installation problems. However, because the bottom plate of the curved trough is elevated from the ground at a predetermined height, the influence of ground unevenness during installation of the curved trough can be reduced. This eliminates or minimizes the need for ground leveling and compaction work, improving installation ease. Furthermore, because the bottom plate is installed slightly higher than the ground, it is easy to install cables when connecting to other troughs, etc.

[0045] The female joint structures on both sides of the side plates can be used to sandwich male joint structures from other troughs, other connecting members, end plates, etc., to form a curved trough connection structure. In this case, by providing a groove in the bottom of the female joint structure and inserting the bottom tip of the end plate into this groove, the end plate can be more stably fixed and prevented from rotating in the width direction. Even when using half-split end plates, a similar effect can be achieved by inserting the upper end plate into the recess in the lower end plate.

[0046] In addition to the openings at both ends, parallel ribs for forming a female coupling structure are also formed at a predetermined position in the middle of the bend. In other words, a bend trough with a small bend angle may be built into the entire bend trough. Therefore, the female coupling structure can be cut along the outside of the parallel ribs at a predetermined position in the middle of the bend and used. By cutting the end of the built-in female coupling structure, a female coupling structure can be formed at the cut portion, allowing it to be used as a bend trough with a smaller bend angle than before cutting. In this case, the vertical rib at a predetermined position in the middle of the bend can be used as a marker for the cutting position. Here, it is desirable that the bottom plate of the female coupling structure formed at a predetermined position in the middle of the bend trough with a small bend angle as described above is also formed lower than the cable storage section.

[0047] The third invention is a connection structure for a branching trough and a linear trough according to the first invention, characterized in that a male joint structure of a linear trough of a predetermined length and having approximately the same cross-sectional dimensions as the trough body is connected to the female joint structure of at least one of the openings of the branching trough, which has an approximately T-shape.

[0048] The first invention may also provide a connection structure for a branching trough and a linear trough, characterized in that the female joint structure of at least one opening of the branching trough, which has an approximately T-shape, is connected to the female joint structure of a linear trough of a predetermined length and having approximately the same cross-sectional dimensions as the trough body via a male-male conversion connection adapter.

[0049] The present invention may also be a connection structure between a branching trough according to the first invention and a curved trough according to the second invention, characterized in that the female joint structure formed in an opening at one end of the curved trough is connected to the female joint structure of at least one opening of the branching trough, which has an approximately T-shape, via a male-male conversion connection adapter.

[0050] Furthermore, the first invention may provide a connection structure for a branch trough and a small-diameter trough, wherein a rectangular end panel wider than the distance between the opposing vertical ribs of the female joint structure is inserted into the female joint structure of at least one opening of the branch trough, which has a roughly T-shape, and the end panel is roughly U-shaped with an opening of a predetermined size formed either below or above, and the male joint structure of the small-diameter trough is arranged in the opening of the end panel, and the flange portion of the male joint structure of the small-diameter trough is fitted into the opening of the end panel as a retaining structure to connect, thereby fixing the male joint structure of the small-diameter trough to the end panel.

[0051] The first aspect of the present invention also provides a connection structure between a branch trough and a conduit, wherein the conduit connected to the generally T-shaped branch trough has an independent wave structure, and the conduit is either an independent wave conduit with a small-diameter section having a circular cross section or a rectangular conduit with alternating large-diameter sections having a rectangular cross section and small-diameter sections having a circular cross section, and a split-half end plate that can be separated into upper and lower halves is disposed in the female joint structure of either of the openings of the generally T-shaped branch trough, the end plate having openings at positions that face each other when split, and the small-diameter section of the conduit is sandwiched between the openings of the end plate to secure the conduit to the end plate. In this case, even if a pulling force is applied to the connected conduit, the large-diameter section of the conduit abuts the end plate, preventing the conduit from coming off.

[0052] Further, in a connection structure between a branching trough and a conduit according to a first invention, the conduit to be connected to the branching trough having a substantially T-shape is a conduit having a circular cross-section and a spiral wave structure, and an inner connection member having a cylindrical portion with a circular cross section having a spiral groove that can be fitted to the 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 spiral groove that can be fitted to the outer circumferential surface of the conduit and a flange portion formed at an end of the cylindrical portion, the cylindrical portion of the outer connection member is screwed onto the inner and outer peripheral surfaces of the conduit, respectively, and is 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.

[0053] In the third invention, a groove having a predetermined length in the width direction of the trough may be formed at approximately the center of the surface of the bottom plate, which is the bottom of the mutually opposing, approximately U-shaped female joint structure, and a protrusion that can fit into the groove may be provided at the bottom tip of the end plate.

[0054] According to the third invention, by positioning the male joint structure of the trough so that it drops from above into the approximately parallel space created by the ribs of the female joint structure of the branching trough, it is possible to directly connect a linear trough to the opening of the branching trough.

[0055] Furthermore, by using a male-male conversion connection adapter, the female joint structure of the branching trough can be connected to the female joint structure of another straight trough or curved trough in an opposing relationship.

[0056] In addition, by using an end panel that is approximately U-shaped and has a rectangular overall shape with an opening of a predetermined size formed below or above the center, it is possible to connect a small-diameter linear trough and a branching trough.

[0057] In addition, by using an end panel that can be separated into upper and lower parts and has an opening of a specified size, both an independently corrugated circular cross-section electrical conduit and a rectangular electrical conduit with a large diameter section and a small diameter section can be connected to the branch trough.

[0058] In addition, the branching trough and the spiral wave electric 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 spiral wave electric conduit and sandwiching an end plate fixed to the opening of the branching trough between both flange portions.

[0059] The fourth invention is a trough line using the branching trough connection structure of the third invention, in which a trough line having a plurality of linear troughs of a predetermined length connected to it is connected to another opening of the branching trough having an approximately T-shape, and a male joint structure arranged at one end of the connection structure of the plurality of connected linear troughs is connected to the female joint structure of the other opening, or a female joint structure arranged at the other end of the connection structure of the plurality of connected linear troughs is connected via a male-male conversion connection adapter, and inside the branching trough, a cable is arranged to have either a branch structure or a bent structure, and is further covered with a trough cover.

[0060] In at least a portion of the trough line of either a straight trough connection structure with a male joint structure at one end or a straight trough connection structure with a female joint structure at the other end, a curved trough having female joint structures at both ends is arranged via a male-male conversion connection adapter, and inside the branching trough, the cable is arranged so as to have either a branch structure or a curved structure, and further a trough cover may be placed on top.

[0061] The cable arranged in the trough forming the trough line may have only a bent structure within the branching trough, and further, the cable may be arranged on one side of the mutually opposing openings and a shielding plate may be arranged on the other side, and the cable may be inserted through the opening of the remaining branch section.

[0062] The cables arranged in the troughs forming the trough line may have only a bent structure within the branching trough, and further, cables may be arranged on one side of the openings of the branching troughs that face each other and on the opening of the branching section, and a shielding plate may be arranged on the other side of the openings of the branching troughs that face each other.

[0063] According to the fourth aspect of the present invention, it is possible to obtain a trough line connected to other troughs such as a straight trough, a curved trough, or a small-diameter trough as the branching trough, or to various types of electric conduit. In this case, it is possible to obtain a trough line having a cable branching structure, or by providing a shielding plate, it is possible to obtain a trough line having only a curved structure without a cable branching structure.

[0064] The fifth invention is a fixing structure for a branch 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 at a predetermined position near the approximate center of the boundary between the main trunk portion and the branch portion, the hollow columnar protrusion has a hollow cylindrical structure, and by inserting and tightening an anchor bolt into the hollow portion of the hollow cylindrical structure, the branch trough having an approximately T-shape is fixed to the asphalt or concrete ground.

[0065] According to the fifth aspect of the present invention, by using the hollow columnar protrusions to fix the trough to the ground with anchor bolts, the branch trough can be reliably fixed to the ground, even on a slope, for example. In this case, the hollow columnar protrusions can reinforce the thin bottom plate, thereby preventing cracks and the like from occurring in the bottom plate.

[0066] The sixth invention is a fixing structure for a curved trough according to the second invention, characterized in that the hollow columnar protrusion that protrudes 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.

[0067] According to the sixth aspect of the present invention, similar to the branch trough fixing structure, the curved trough can be reliably fixed to the ground by using the hollow columnar protrusions and anchor bolts to fix the trough to the ground, even on a slope, for example. In this case, the hollow columnar protrusions can reinforce the thin bottom plate, thereby preventing cracks from occurring in the bottom plate.

[0068] A seventh invention is a method for connecting a cable protection member to a branching trough according to the first invention, wherein the female joint structure is formed by extending the vertical ribs of a predetermined height substantially parallel to each other in a vertical direction inward from the side plate so as to face each other at an end of at least one of the three openings of the branching trough and at a position near the end of the opening and spaced a predetermined distance from the end of the opening, This is a method for connecting a cable protection member to a branching trough, characterized in that the flange portion of the male joint structure of the trough is fixed directly to the space formed by the vertical ribs in which both end faces are approximately parallel, or the female joint structure of the trough is fixed via a male-male conversion connection adapter, or the flange portion of the male joint structure of the small-diameter trough is fixed via an end plate, or the small-diameter portion of an independent corrugated conduit having a circular or rectangular cross section is fixed by sandwiching it between the end plate, or the inner connecting member and the outer connecting member are screwed to the end of the helical corrugated conduit via the end plate and the end plate is sandwiched between the flange portions of the inner connecting member and the outer connecting member.

[0069] According to the seventh invention, it is possible to connect various cable protection members to the female joint structure of the branch trough via the end plate. Here, the seventh invention can be applied to troughs of other structures as long as the female joint structure is the same as that of the seventh invention, and therefore, although not particularly specified in this application, it is possible to obtain a method for connecting a cable protection member to a curved trough or a straight trough.

[0070] The present invention improves the structural strength of the trough without providing vertical ribs on the outside of the trough side plates by devising a shape for the trough side plates and providing a bent portion, and it is possible to obtain a lightweight, thin-walled branching trough or curved trough which has the characteristic that the vertical ribs at the bent portions of the side plates serve as a reinforcing structure for the female joint structure and the horizontal rib portions connecting the bent portions, and also serve as a structure for fixing the trough lid.

[0071] Furthermore, according to one aspect of the present invention, it is possible to provide a branch trough, a curved trough, etc. that can be easily fixed to the ground with anchor bolts and that allows cables to be easily laid, even when the ground to be installed is uneven or sloped, etc. Furthermore, by fixing the hollow columnar protrusions of the branch trough or curved trough with anchor bolts, it is possible to obtain a fixing structure for these troughs to asphalt or concrete ground.

[0072] In addition, by attaching a male-male conversion connection adapter or end plate to the female joint structure of the branch trough, various connection structures between the branch trough and other troughs or electrical conduits and connection methods for realizing these connection structures can be obtained. Furthermore, using this connection structure, it is possible to provide a trough line in which multiple linear troughs of a predetermined length are connected.

[0073] 1 is an upper perspective view showing a branch trough 1 and a trough lid 3. A lower perspective view of the branch trough 1. A plan view of the branch trough 1. A bottom view of the branch trough 1. An enlarged view of a hollow columnar protrusion 27 showing the state before hole drilling. An enlarged view of the hollow columnar protrusion 27 showing the state after guide holes have been drilled in the bottom plate. An enlarged view of the hollow columnar protrusion 27 showing the state after through holes have been drilled in the hollow columnar protrusion. A view showing a branch trough fixing structure 40. Bottom views of other branch troughs 1. Bottom views of other branch troughs 1. An upper perspective view showing a curved trough 41 and a trough lid 43. A lower perspective view of the curved trough 41. A plan view of the curved trough 41. A bottom view of the curved trough 41. A lower perspective view of another curved trough 41. An enlarged view of a hollow columnar protrusion 67 showing the state before hole drilling. 1 is an enlarged view of a hollow columnar protrusion 67, showing the state after a guide hole has been drilled in the bottom plate. FIG. 2 is an enlarged view of a hollow columnar protrusion 67, showing the state after a through hole has been drilled in the hollow columnar protrusion. FIG. 3 is a view showing a curved trough fixing structure 40a. FIG. 4 is a plan view of a curved trough 41 before cutting. FIG. 5 is a plan view of a curved trough 41 after cutting. FIG. 6 is a view showing the angle of the curved trough 41. FIG. 7 is a view showing a state before a branch trough 1 and a straight trough 81 are connected to a trough connection structure 90. FIG. 8 is a view showing a trough connection structure 90 in which a branch trough 1 and a straight trough 81 are connected. FIG. 9 is an enlarged view of the trough connection structure 90. FIG. 10 is a view showing a state before a branch trough 1 and a straight trough 81 are connected to a trough connection structure 90a. FIG. 11 is a view showing a state before a branch trough 1 and a straight trough 81 are connected to a trough connection structure 90a. FIG. 12 is a view showing a process of constructing a trough connection structure 90a in which a branch trough 1 and a straight trough 81 are connected. 1 is an enlarged view showing the trough connection structure 90a in a state before the branch trough 1 and the straight trough 81 are connected; an enlarged view showing the trough connection structure 90a in which the branch trough 1 and the straight trough 81 are connected; a view showing the trough connection structure 90b in a state before the branch trough 1 and the curved trough 41 are connected; a view showing the trough connection structure 90b in which the branch trough 1 and the curved trough 41 are connected; a view showing the trough connection structure 90c in a state before the branch trough 1 and the small diameter trough 87 are connected; a view showing the trough connection structure 90c in which the branch trough 1 and the small diameter trough 87 are connected; a front view showing the end plate 93; a plan view showing the male joint structure 83a of the small diameter trough 87; a view showing the trough connection structure 90d in a state before the branch trough 1 and the rectangular electrical conduit 101 are connected; 10 is a diagram showing a trough connection structure 90d in which a branch trough 1 and a rectangular electrical conduit 101 are connected. FIG.1 is an enlarged view of an end plate 93a of a trough connection structure 90d before the branch trough 1 and the rectangular conduit 101 are connected; an enlarged view of an end plate 93a of the trough connection structure 90d in which the branch trough 1 and the rectangular conduit 101 are connected; a diagram showing a trough connection structure 90e in which the branch trough 1 and the independent wave conduit 101a are connected; an enlarged view of an end plate 93a of a trough connection structure 90e in which the branch trough 1 and the independent wave conduit 101a are connected; a diagram showing a state before the inner connection member 97a and the outer connection member 97b are fixed to the helical wave conduit 101b; a diagram showing a state in which only the outer connection member 97b is connected to the helical wave conduit 101b; a diagram showing a state in which both the inner connection member 97a and the outer connection member 97b are connected to the helical wave conduit 101b. A diagram showing a trough connection structure 90f connecting a branch trough 1 and a helical wave conduit 101b. A diagram showing an end plate 93b. A diagram showing the trough line 100, showing a state where the trough lid is removed. A diagram showing the trough line 100, showing a state where the trough lid is in place. A diagram showing the trough line 100a, showing a state where the trough lid is removed. A diagram showing the trough line 100a, showing a state where the trough lid is in place. A diagram showing the trough line 100b. A diagram showing the trough line 100c. An enlarged view showing the shielding plate 113.

[0074] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an upper perspective view showing a branching trough 1 and a trough cover 3, Fig. 2 is a lower perspective view of the branching trough 1, Fig. 3A is a plan view of the branching trough 1, and Fig. 3B is a bottom view of the branching trough 1. The branching trough 1 is mainly composed of side plates 7 forming both side surfaces and a bottom plate 5 forming the bottom surface, with both side plates 7 standing upright to surround the bottom plate 5, and the trough has a generally U-shaped cross section and a generally T-shaped plan view.

[0075] The branching trough 1 and the trough lid 3 are made of, for example, resin and are molded by press molding or injection molding. The branching trough 1 is covered with the trough lid 3 before use. In the following description, the trough lid 3 is not shown unless otherwise specified.

[0076] 3A and other figures, the bottom plate 5 is formed as a continuous, integral plate member comprising a substantially rectangular main trunk 9 and a branch section 11 formed to extend from one long side of the main trunk 9, facing the long side of the main trunk 9, in a direction perpendicular to the longitudinal direction of the main trunk 9. In other words, the bottom plate 5 is substantially T-shaped in plan view, and the branch trough 1 has the main trunk 9 and the branch section 11. The branch section 11 is formed to extend from one long side of the main trunk 9 in a direction perpendicular to the longitudinal direction of the main trunk 9, gradually reducing in diameter in a substantially arc shape.

[0077] The side plate 7 is formed to follow the outer shape of the bottom plate 5. That is, the side plate 7 has a straight portion formed on one long side of the trunk portion 9 and a curved portion 13 that forms the outer edge of the branch portion 11 that extends in a substantially arc-like shape with a reduced diameter.

[0078] The roughly T-shaped branching trough 1 is open in three directions. That is, two openings 15a of a predetermined width are formed symmetrically at both longitudinal ends of the main trunk 9, and further, an opening 15b separate from the two openings 15a of the main trunk 9 is formed at the tip of the branching section 11, and is roughly perpendicular to the two openings 15a of the main trunk 9.

[0079] A female joint structure 23a for connecting a cable protection member, which will be described later, is formed in each of the openings 15a at both longitudinal ends of the main trunk 9. The female joint structure 23a has parallel vertical ribs 21 spaced a predetermined distance apart. Similarly, a female joint structure 23b for connecting a cable protection member, which will be described later, is formed in each of the openings 15b at the tip of the branch section 11. The female joint structure 23b has parallel vertical ribs 21 spaced a predetermined distance apart. In other words, the female joint structure 23b at the end of the branch section 11 has the same structure as the female joint structure 23a, which has parallel vertical ribs 21, in the openings 15a formed at both longitudinal ends of the main trunk 9.

[0080] More specifically, near openings 15a and 15a at both longitudinal ends of main trunk 9, a pair of generally U-shaped female coupling structures 23a are formed that face each other in plan view and have generally parallel vertical ribs 21 spaced a predetermined distance apart and extending inward in a direction perpendicular to side plates 7 of the straight and curved portions of main trunk 9. Furthermore, near openings 15b and 15b at the tip of branched portion 11, generally parallel vertical ribs 21 spaced a predetermined distance apart and extending inward in a direction perpendicular to the curved portion are provided, forming a pair of generally U-shaped female coupling structures 23b separate from female coupling structure 23a formed at opening 15a of main trunk 9, with the vertical ribs 21 facing each other and formed in a generally U-shape in plan view.

[0081] That is, the female joint structure 23a has vertical ribs 21 of a predetermined height provided substantially parallel to each other at the end of each opening 15a and at a position near the end of the opening 15a and spaced a predetermined distance from the end of the opening 15a. The vertical ribs 21 extend inward from the opposing side plates 7 so as to face each other in a direction perpendicular to the side plates 7, thereby forming a pair of substantially U-shaped structures facing each other in plan view. Similarly, the female joint structure 23b has vertical ribs 21 of a predetermined height provided substantially parallel to each other at the end of the opening 15b and at a position near the end of the opening 15b and spaced a predetermined distance from the end of the opening 15b. The vertical ribs 21 extend inward from the opposing side plates 7 so as to face each other in a direction perpendicular to the side plates 7, thereby forming a pair of substantially U-shaped structures facing each other in plan view. In this way, the female joint structure 23b at the tip of the branch portion 11 has the same structure as the female joint structures 23a formed at both ends of the main trunk portion 9 in the longitudinal direction.

[0082] The bottom plate surfaces of the female joint structures 23a, 23b are formed a predetermined height lower than the bottom plate surfaces of the portions other than the female joint structures 23a, 23b. By doing so, when the male joint structure of another trough is overlapped and connected to the female joint structures 23a, 23b, the level of the upper surface of the bottom of the other trough and the branch trough 1 can be aligned. Note that a groove 31 having a predetermined length in the width direction of the trough is formed approximately at the center of the surface of the bottom plate 5, which is the bottom of the mutually opposing, approximately U-shaped female joint structures 23a, 23b. The function of the groove 31 will be described later.

[0083] Near each end of the side plate 7 of the straight portion of the main trunk 9 and the bent portion 13 of the branch portion 11 (i.e., the portion where the diameter decreases from the main trunk 9 toward the branch portion 11), bent portions 17 that protrude inward are formed at a predetermined distance from each other. The bent portions 17 are provided so as to connect the inside of the opening 15a at one end of the main trunk 9 or the inside of the opening 15a at the other end of the main trunk 9 with the inside of the opening 15b at the end of the branch portion 11. In other words, the bent portions 17 formed in the main trunk 9 are formed so as to connect the vicinity of both ends of the long sides of the main trunk 9, and the bent portions 17 formed in the bent portions are formed so as to connect the vicinity of both ends of the bent portion.

[0084] Horizontal ribs 19 are formed at the top of the side plate 7, at the top of the straight section and at the top of the bent section 17 of the curved section, at a predetermined distance from each other, to connect both ends of each bent section 17. The horizontal ribs 19 are formed in a substantially horizontal direction so as to be perpendicular to the vertical ribs 21, which are provided in a substantially vertical direction. The horizontal ribs 19 also serve as mounting portions for fastening brackets for attaching the trough lid. In other words, when the trough lid 3 is placed on the branching trough 1, the trough lid 3 can be fixed to the horizontal ribs 19 of the branching trough 1 using fastening brackets (not shown).

[0085] Each end of the bent section 17, which is provided to connect the inside of the opening 15a at one end of the main trunk 9 or the inside of the opening 15a at the other end of the main trunk 9 with the inside of the opening 15b at the end of the branch section 11, also serves as the inner vertical rib 21 of the female joint structures 23a, 23b provided at the ends of the openings 15a, 15b of the main trunk 9 and the branch section 11. In other words, no reinforcing vertical rib is formed on the outside of the side plate 7 of the approximately arc-shaped bent section 13.

[0086] 2 and 3B , in the female joint structures 23a and 23b, the side plates 7 protrude at a predetermined height from the rear surface of the bottom plate 5, forming foot portions 25. That is, the foot portions 25 protrude downward from the bottom surface side of the branching trough 1, and most of the bottom surface of the bottom plate 5 other than the foot portions 25 is positioned higher than the foot portions 25. Therefore, when the branching trough 1 is installed on the ground, the bottom plate 5 is supported by the foot portions 25 at a predetermined height above the ground surface, and a space is formed on the rear surface of the bottom plate 5.

[0087] On the back surfaces of the main trunk portion 9 and the branch portion 11, hollow columnar protrusions 27 are formed at predetermined positions in the aforementioned space, protruding downward from the bottom plate 5 at a predetermined height. In addition, on the back surface of the bottom plate 5 of the branch trough 1, which has a substantially T-shape, bottom reinforcing ribs 29 are provided that protrude downward at positions different from the hollow columnar protrusions 27. A plurality of bottom reinforcing ribs 29 of a predetermined length are formed in parallel to each other, starting from positions each shifted a predetermined distance from the center of the longitudinal direction of the linear side plate 7 of the main trunk portion 9, toward the opening 15b of the branch portion 11 that extends opposite to the side plate 7, connecting the two.

[0088] 4A 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. A minute recess is formed on the upper 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 approximately 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.

[0089] To utilize the hollow columnar protrusion 27, first, as shown in FIG. 4B , a guide hole of a predetermined size is formed in the bottom plate 5 above the hollow columnar protrusion 27, using the aforementioned minute recess as a guide. In this case, the guide hole formed 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. 4C , a hole of approximately the same diameter as the hollow portion of the hollow columnar protrusion 27 is formed from above or below, thereby connecting the upper surface of the bottom plate 5 to the lower portion of the hollow columnar protrusion 27 via a through-hole. In this way, a two-stage hole may be formed below the guide hole, with two stages of holes smaller than the guide hole and approximately the same diameter as the hollow portion of the hollow columnar protrusion 27. Alternatively, a single-stage through-hole of approximately the same diameter as the hollow portion of the hollow columnar protrusion 27 may be formed without a guide hole.

[0090] 5 is a diagram showing a branch trough fixing structure 40 having a substantially T-shape in which the branch trough 1 is fixed to the ground surface 33 after processing in this manner. At a predetermined position on the main trunk 9, a predetermined distance away from the boundary between the main trunk 9 and the branch section 11, a hollow columnar protrusion 27 protruding downward from the back surface of the bottom plate 5 at a predetermined height is formed as a fixing portion for an anchor bolt 37. The hollow columnar protrusion 27 has a hollow cylindrical structure, and by inserting the anchor bolt 37 into the hollow portion of the hollow cylindrical structure and tightening it, the branch trough 1 having a substantially T-shape is fixed to the ground surface 33, such as asphalt or concrete ground.

[0091] In this case, as described above, downwardly protruding feet 25 are formed at the ends of the branch troughs 1. Therefore, when the branch troughs 1 are fixed to the ground surface 33, a space 35 can be formed between the bottom plate 5 and the ground surface 33.

[0092] 4A , when anchor bolt fixing holes are not machined and fixing is not performed with anchor bolts 37, the top surface of the hollow columnar protrusion 27 is blocked by the bottom plate 5, thereby preventing foreign matter from entering the inside of the branch trough 1 from below. On the other hand, when fixing is performed with anchor bolts 37, 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.

[0093] The shape of the hollow columnar protrusion 27 may be a substantially cylindrical shape as shown in the figure, or may be any other shape that allows the formation of an anchor bolt fixing hole, such as a substantially square column shape or a substantially polygonal shape. Furthermore, as shown in Figures 6A and 6B, the hollow columnar protrusion 27 may be disposed in multiple locations. That is, it is sufficient that at least one hollow columnar protrusion 27 is provided and formed as an anchor bolt fixing portion.

[0094] Figure 6A shows an example in which three hollow columnar protrusions 27 are provided at approximately equal intervals at predetermined positions on the main trunk 9, and bottom reinforcing ribs 29 are provided between each hollow columnar protrusion 27 so as to connect the long side of the main trunk 9 to the opening side of the branch section 11 opposite it. Figure 6B shows an example in which three hollow columnar protrusions 27 are provided linearly at approximately equal intervals at predetermined positions on the main trunk 9. Figure 3B shows an example in which a hollow columnar protrusion 27 is positioned approximately in the center, and two bottom reinforcing ribs 29 are provided on either side of it, as in the case of Figure 6A. As described above, by appropriately combining both to reinforce the bottom plate, it is possible to reinforce the bottom plate and at the same time make it easier to ensure a predetermined space on the back surface of the trough bottom plate 5.

[0095] 6A and 6B , providing multiple hollow columnar protrusions 27 typically provides both the anchor bolt fixing holes and the bottom reinforcement. Although a bottom reinforcing rib 29 may also be provided in addition to the hollow columnar protrusions 27, providing multiple hollow columnar protrusions 27 spaced a predetermined distance apart increases the flexibility of anchor bolt fixing positions, while also firmly securing the branch trough 1 by bolting at multiple locations. Furthermore, providing multiple hollow columnar protrusions 27 is preferable because it ensures a larger amount of free space on the back surface of the trough than providing a bottom reinforcing rib 29. In this case, a short rib with a bent structure may or may not be provided at the end of the side plate 7, as shown in the figure, only near the end of the side plate 7. The hollow columnar protrusions occupy less length and area than the bottom reinforcing ribs, making them easier to install, and they increase the options for anchor bolt fixing positions, while at the same time, by fixing them with bolts at multiple points, the branch trough 1 can be firmly fixed.

[0096] Next, the curved trough will be described. Fig. 7 is an upper perspective view showing the curved trough 41 and the trough lid 43, Fig. 8 is a lower perspective view of the curved trough 41, Fig. 9A is a plan view of the curved trough 41, and Fig. 9B is a bottom view of the curved trough 41. The curved trough 41 mainly comprises side plates 47 forming both side surfaces and a bottom plate 45 forming the bottom surface. Both side plates 47 stand upright to surround the curved portion of the bottom plate 45, and the cross section is approximately U-shaped. Note that, like the branching trough 1, the curved trough 41 and the trough lid 43 are made of resin, for example, and are molded by press molding or injection molding.

[0097] 9A and other figures, the bottom plate 45 has a curved portion that is curved at a predetermined angle in a predetermined direction in a plan view. The curved portion is made up of an inner curved portion 59 that forms the inside of the curve and an outer curved portion 61 that forms the outside of the curve. The side plates 47 that form the inner curved portion 59 surround the curved portion of the bottom plate 45, and the side plates 47 on both sides of the side plate 47 that forms the outer curved portion 61 rise up from the curved portion of the bottom plate 45 to form a curved portion that is approximately arc-shaped. A substantially U-shaped opening 49 is formed at each end of the side plate 47 that forms the inner curved portion 59 and the side plate 47 that forms the outer curved portion 61.

[0098] At the ends of the openings 49 at both ends of the side plates 47 and at predetermined positions near the ends of the openings 49 at both ends, substantially parallel vertical ribs 55 are formed at a predetermined distance from each other on both sides of the curved portion of each side plate 47, extending inward in a direction perpendicular to the curved portion. This forms a pair of substantially U-shaped female coupling structures 57a facing each other in a plan view, each having the vertical ribs 55. In the female coupling structures 57a, the respective vertical ribs 55 are formed facing inward from the opposing side plates 47 in a direction perpendicular to the curved portion. In other words, the female coupling structures 57a form a pair of substantially U-shaped structures facing each other in a plan view.

[0099] Similar to the openings 49 at both ends of the side plate 47, a pair of mutually opposing, substantially U-shaped female joint structures 57b 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 near the predetermined position in the middle of the bent portion. The female joint structures 57b formed at a predetermined position in the middle of the bent portion have substantially parallel vertical ribs 55 of a predetermined height formed on each of the opposing side plates 47 inwardly and 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 near the predetermined position in the middle of the bent portion.

[0100] As described above, the side plate 47 forms a substantially arc-shaped curved portion that forms the outer curved portion 61 and the inner curved portion 59. The side plate 47 of the inner curved portion 59 and the outer curved portion 61 has bent portions 51 formed at a predetermined distance from each other at a predetermined position near the opening 49 and a predetermined position intermediate the bent portion, the bent portions 51 also serving as inwardly protruding vertical ribs 55. The bent portions 51 are provided to connect the opening 49 at one end of the bent trough 41 to a predetermined position intermediate the bent portion. That is, the bent portion 51 provided at a predetermined position near the opening 49 also serves as the inner vertical rib 55 of the female coupling structure 57a near the opening 49, and the bent portion 51 formed at a predetermined position intermediate the bent portion also serves as the inner vertical rib 55 of another female coupling structure 57b.

[0101] Horizontal ribs 53 are provided at both ends of the upper portion of the bent portion 51, which also serve as vertical ribs, and are formed at a predetermined distance from each other at a predetermined position near the opening 49 of the side plate 47 and at a predetermined position midway between the bent portion. The horizontal ribs 53 are formed to connect the vertical rib 55 on the inside of the female coupling structure 57a to the vertical rib 55 on the inside of the female coupling structure 57b formed at a predetermined position midway between the bent portion. That is, the horizontal ribs 53 are formed to connect the vertical ribs 55 formed at both ends of the bent portion 51. A fastening bracket for attaching the trough lid 43 can be attached to the horizontal ribs 53. In this way, the horizontal ribs 53 also serve as fastening bracket attachment portions for attaching fastening brackets for attaching the trough lid. Therefore, when the trough lid 43 is placed on the curved trough 41, the trough lid 43 can be fixed to the horizontal ribs 53 of the curved trough 41 using fastening brackets (not shown).

[0102] The horizontal ribs 53 are formed in a substantially horizontal direction so as to be perpendicular to the vertically extending vertical ribs 55. Both ends of the horizontal ribs 53 of the inner curved portion 59 and both ends of the horizontal ribs 53 of the outer curved portion 61 are located on the same centerline from the center of curvature of the curved portion. That is, the horizontal ribs 53 of the outer curved portion 61 are formed longer than the horizontal ribs 53 of the inner curved portion 59. Furthermore, no reinforcing vertical ribs need be provided on the outside of each of the side plates 47 forming the inner curved portion 59 and the outer curved portion 61. Since the vertical ribs 55 of the inner curved portion and the vertical ribs 55 of the outer curved portion are both formed on the same centerline, the width between the vertical ribs 55 of the substantially U-shaped opening on the outer curved portion 61 side that forms the pair of substantially U-shaped female joint structures 57a is greater than the width between the vertical ribs 55 of the substantially U-shaped opening on the opposing inner curved portion 59 side.

[0103] The bottom plate surfaces of the female coupling structures 57a formed at least at both ends of the bent portion are formed a predetermined height lower than the bottom plate surfaces of the portions other than the female coupling structures 57a. By doing so, when the male coupling structure of another trough is overlapped and connected to the female coupling structure 57a, the level of the upper surface of the bottom of the other trough and the curved trough 41 can be aligned. A groove 63 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 coupling structures 57a facing each other in a plan view. The function of the groove 63 will be described later.

[0104] 8 and 9B , in the female joint structure 57a, the side plate 47 protrudes at a predetermined height from the rear surface of the bottom plate 45 to form the foot portion 65. That is, the foot portion 65 protrudes downward from the bottom surface side of the curved trough 41, and most of the bottom surface of the bottom plate 45 other than the foot portion 65 is positioned higher than the foot portion 65. Therefore, when the branching trough 1 is installed on the ground, the foot portion 65 supports the bottom plate 45 at a predetermined height above the ground surface, and a space is formed on the rear surface of the bottom plate 45.

[0105] 8, a hollow columnar protrusion 67 is formed on the back surface of the bottom plate 45 at a predetermined position in the space defined by the inner curved portion 59 and the outer curved portion 61, protruding downward from the bottom plate 45 at a predetermined height. Alternatively, only one or more hollow columnar protrusions 67 may be formed on the back surface of the bottom plate 45 as needed. Alternatively, a bottom reinforcing rib 69 may be formed on the back surface of the bottom plate 45, connecting the inner curved portion 59 and the outer curved portion 61. The bottom reinforcing rib 69 is formed in a direction toward the center of curvature of the inner curved portion 59 and the outer curved portion 61. In this case, the bottom reinforcing rib 69 may be formed on the same straight line including the hollow columnar protrusion 67 so as to sandwich the hollow columnar protrusion 67, or may be spaced a predetermined distance apart.

[0106] 10, a plurality of hollow columnar protrusions 67 may be provided. In the illustrated example, the hollow columnar protrusions 67 are provided on the back surface of the bottom plate 45 at the center in the width direction between the bent portion 51 of the inner bent portion 59 of the side plate 47 and the bent portion 51 of the outer bent portion 61, and on the back surface of the bottom plate 45 at the center in the width direction between a female joint structure 57b provided in the middle of a bent portion spaced a predetermined distance from one end of the bent portion and a female joint structure 57a provided at the other end of the bent portion.

[0107] In this case, providing multiple hollow columnar protrusions 67 typically provides both the effect of anchor bolt fixing holes and the effect of reinforcing the bottom surface. Furthermore, a bottom reinforcing rib 69 may also be provided in addition to the hollow columnar protrusions 67. However, providing multiple hollow columnar protrusions 67 spaced a predetermined distance apart increases the options for anchor bolt fixing positions, and at the same time, by fastening the bolts at multiple locations, the branch trough 1 can be firmly fixed. Furthermore, providing multiple hollow columnar protrusions 67 is preferable because it ensures a larger amount of space free from obstacles on the back surface of the trough than providing a bottom reinforcing rib 69. In this case, short ribs with a bent structure may or may not be provided at the ends of the side plates only near the ends of the side plates.

[0108] 11A is an enlarged cross-sectional view of the vicinity of the hollow columnar protrusion 67. As shown in the figure, the hollow columnar protrusion 67 is substantially circular (cylindrical) and hollow at the bottom. That is, the top of the hollow columnar protrusion 67 is closed by the bottom plate 45. A minute recess is formed on the upper surface of the bottom plate 45 above the hollow columnar protrusion 67. For example, it is desirable that the outer diameter of the hollow columnar protrusion 67 is approximately 33 mm, the inner diameter (hole) is 10 mm, and the height (protrusion height from the bottom surface of the bottom plate 45) is at least 8 mm or more and 30 mm or less.

[0109] To utilize the hollow columnar protrusion 27, as in the branch trough 1 described above, first, as shown in FIG. 11B , a guide hole of a predetermined size is provided in the bottom plate 45 above the hollow columnar protrusion 67, using the aforementioned minute recess as a guide. In this case, the guide hole provided in the bottom plate 45 is larger than the inner diameter of the hollow of the hollow columnar protrusion 67. Next, as shown in FIG. 11C , a hole of approximately the same diameter as the hollow portion of the hollow columnar protrusion 67 is provided from above or below, thereby connecting the upper surface side of the bottom plate 45 and the lower portion of the hollow columnar protrusion 67 via a through hole. The hollow columnar protrusion 67 can be provided as a two-stage hole, but it can also be a single-stage through hole of approximately the same diameter as the hollow portion of the hollow columnar protrusion 67 without providing a guide hole.

[0110] 12 is a diagram showing a curved trough fixing structure 40a in which the curved trough 41 has been fixed to a ground surface 71 after being processed in this manner. A hollow columnar protrusion 67 that protrudes downward from the back surface of the bottom plate 45 at a predetermined height is formed as a fixing portion for an anchor bolt 75. The hollow columnar protrusion 67 has a hollow cylindrical structure, and the curved trough 41 is fixed to a ground surface 71 such as asphalt or concrete ground by inserting the anchor bolt 75 into the hollow portion of the hollow cylindrical structure and tightening it.

[0111] In this case, as mentioned above, a foot portion 65 that protrudes downward is formed at the end of the curved trough 41, so that when the curved trough 41 is fixed to the ground surface 71, a space 73 is formed between the bottom plate 45 and the ground surface 71.

[0112] 11A , when the curved trough 41 is not fixed with the anchor bolts 75, the top surface of the hollow columnar protrusion 67 is blocked by the bottom plate 45, thereby preventing foreign matter from entering the interior from below. On the other hand, when the curved trough 41 is fixed with the anchor bolts 75, the top surface of the hollow columnar protrusion 67 may be opened in advance. That is, the top surface of the hollow columnar protrusion 67 may be blocked by the bottom plate 45, or the top surface of the hollow columnar protrusion 67 may be open.

[0113] The shape of the hollow columnar protrusion 67 may be a substantially cylindrical shape as shown in the figure, or may be any other shape that allows the formation of an anchor bolt fixing hole, such as a substantially square column shape or a substantially polygonal shape. Furthermore, the hollow columnar protrusion 67 may be disposed in multiple locations. That is, it is sufficient that at least one hollow columnar protrusion 67 is provided and formed as an anchor bolt fixing portion.

[0114] Next, an example of how to use the curved trough 41 will be described. Fig. 13A is a plan view of the curved trough 41. As described above, the curved trough 41 has a female joint structure 57b formed in the middle of the curved portion, in addition to the female joint structures 57a formed in the openings 49 at both ends. That is, the female joint structure 57b is formed by forming a bent portion 51 at a predetermined position midway between one end of the curved portion of the curved trough 41 and the other end a predetermined distance away, and by forming vertical ribs 55 of a predetermined height in a direction perpendicular to the bottom plate 45 and substantially parallel to each other so as to extend inward from the side plate 47 at a predetermined position near the bent portion 51, thereby forming the female joint structure 57b.

[0115] The outer longitudinal ribs 55 of the female coupling structure 57b are formed substantially parallel to each other in a direction perpendicular to the bottom plate 45 and at a predetermined height so as to extend inward from the side plate 47. Cutting is performed along the longitudinal ribs 55 so as to connect the outer surfaces of the longitudinal ribs 55 of the inner bent portion 59 and the outer bent portion 61, which are formed perpendicular to the curve forming the bent portion (line A in the figure). By cutting in this manner, the trough 41 can be used as a bent trough 41 having a bend angle smaller than the bend angle before cutting, as shown in Figure 13B. That is, the bent trough 41 before cutting incorporates the structure of a bent trough having a bend angle smaller than the bend angle before cutting, which can be obtained by cutting.

[0116] The curved trough 41 cut in this way has the female joint structure 57a formed at the opening 49 before cutting at one end, and the female joint structure 57b formed at a predetermined position in the middle of the curved portion before cutting at the other end. In other words, because the female joint structures 57a, 57b 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 41 before cutting.

[0117] FIG. 14 is a diagram showing the bending angle of such a curved trough 41. For example, if the bending angle (θ1 in the figure) of the curved trough 41 connecting the openings 49 at both ends before cutting is 45°, the bending angle (θ2 in the figure) after cutting is 30°. If the bending angle (θ1 in the figure) of the curved trough 41 connecting the openings 49 at both ends before cutting is 60°, the bending angle (θ2 in the figure) after cutting is 45°. Also, if the bending angle (θ1 in the figure) of the curved trough 41 connecting the openings 49 at both ends 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. Furthermore, as described above, even a curved trough 41 with a small bending angle after cutting can be connected to other troughs, etc., because it has female joint structures 57a, 57b at both ends. In this case, it goes without saying that the angle from the open end of the bent trough 41 to the female joint structure 57b formed at a predetermined position in the middle of the bent section must be set to 60°, 45°, or 30° depending on the above angle before cutting.

[0118] Next, a trough connection structure using a branching trough 1 will be described. Figures 15A and 15B are diagrams showing a connection process for a connection structure (trough connection structure 90) between a branching trough 1 having a generally T-shape and a linear trough 81. The linear trough 81 has a male joint structure 83 at one end and a female joint structure 85 at the other end. A plurality of linear troughs 81 are arranged in the longitudinal direction, and the male joint structure 83 of one adjacent linear trough 81 is connected by dropping it from above the female joint structure 85 of another adjacent linear trough 81, thereby allowing the female joint structure 85 and the male joint structure 83 to fit together.

[0119] In the trough connection structure 90, as shown in Fig. 15A, the female joint structure 23a at the opening 15a of the branch trough 1 and the male joint structure 83 of the linear trough 81 are arranged opposite each other, and the male joint structure 83 of the linear trough 81 in Fig. 15B is dropped into the female joint structure 23a of the branch trough 1, thereby connecting the branch trough 1 and the linear trough 81. Here, the horizontal ribs 19 of the branch trough 1 can be used as metal fitting attachment parts, but as shown in the figure, they can also be provided at only two locations, diagonally opposite the main trunk 9 and the bend section 13. Similarly, it is also possible to provide them at four locations on all horizontal ribs 19: two locations on the main trunk 9 and two locations on the branch section 11. For simplicity, the drawings numbered from Figure 16 onwards show metal fitting attachment portions formed at only two diagonal positions, but it is not necessarily intended that metal fitting attachment portions be formed at two diagonal positions; metal fitting attachment portions may be attached at only two positions on the bend 13, or metal fitting attachment portions may be formed at all four positions on the horizontal rib 19, and all of these cases are included.

[0120] Figure 16 is a partially enlarged view of the trough connection structure 90. As described above, the female coupling structure 23a is formed by parallel longitudinal ribs. The male coupling structure 83 has a flange portion whose end is widened, and this flange portion fits between the longitudinal ribs of the female coupling structure 23a to connect the two. The linear trough 81 may be connected to the opening 15b of the branch section 11 instead of the opening 15a of the main trunk 9 of the branch trough 1. In this way, in the trough connection structure 90, the male coupling structure 83 of the linear trough 81, whose trough body has approximately the same cross-sectional dimensions and a predetermined length, is connected to the female coupling structure 23a, 23b of at least one opening 15a, 15b of the branch trough 1, which has an approximately T-shape.

[0121] Next, we will explain another trough connection structure using the branch trough 1. Figures 17A and 17B are diagrams showing the connection process of the connection structure (trough connection structure 90a) between the branch trough 1 having a substantially T-shape and the linear trough 81.

[0122] In the trough connection structure 90a, as shown in Fig. 17A, the female joint structure 23a at the opening 15a of the branching trough 1 and the female joint structure 85 of the linear trough 81 are arranged opposite each other. That is, the female joint structures of the branching trough 1 and the linear trough 81 face each other. Here, as shown in Fig. 17B, the female joint structures of the branching trough 1 and the linear trough 81 arranged opposite each other are connected by a male-male conversion connection adapter 91.

[0123] 18A is an enlarged view of the female joint structure 23a of the branching trough 1 and the female joint structure 85 of the linear trough 81 arranged opposite each other. As described above, each female joint structure 23a, 85 is formed in a substantially U-shape with parallel vertical ribs. That is, the U-shaped portions of each female joint structure 23a, 85 are arranged side by side, with the openings facing each other.

[0124] As shown in Figure 18B, this embodiment uses a male-female conversion connection adapter 91. The male-female conversion connection adapter 91 has a shape in which the center of 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 91 are roughly U-shaped and open outward in a plan view.

[0125] The male-male conversion connection adapter 91 may have a flat structure with approximately U-shaped openings that open outward at both ends, or an approximately U-shaped bent structure, with approximately U-shaped, parallel mating portions having a notch in the center that opens outward, and two opposing female joint structures mating with these approximately U-shaped cutout portions.

[0126] The female joint structure 23a and the female joint structure 85 can be connected by arranging the male / male conversion connection adapter 91 so as to straddle the female joint structure 23a of the branching trough 1 and the female joint structure 85 of the linear trough 81, and fitting the longitudinal ribs of the female joint structure 23a and the female joint structure 85 into the central cutout portion of the male / male conversion connection adapter 91. In this way, in the trough connection structure 90a, the female joint structure 85 of a linear trough of a predetermined length and having substantially the same cross-sectional dimensions of the trough body is connected via the male / male conversion connection adapter 91 to the female joint structure 23a, 23b of at least one opening 15a, 15b of the substantially T-shaped branching trough 1.

[0127] Next, we will explain another trough connection structure using the branch trough 1. Figures 19A and 19B are diagrams showing a connection process of a connection structure (trough connection structure 90b) between a branch trough 1 having a substantially T-shape and a curved trough 41.

[0128] 19A , in the trough connection structure 90b, the female joint structure 23a at the opening 15a of the branching trough 1 and the female joint structure 57a of the curved trough 41 are arranged opposite each other. That is, the female joint structures of the branching trough 1 and the curved trough 41 face each other.

[0129] In this embodiment, as in the trough connection structure 90a described above, a male / female conversion connection adapter 91 is used. The male / female conversion connection adapter 91 is arranged to straddle the female joint structure 23a of the branch trough 1 and the female joint structure 57a of the bent trough 41, and the female joint structure 23a and the female joint structure 57a can be connected by fitting the longitudinal ribs of the female joint structure 23a and the female joint structure 57a into the central cutout portion of the male / female conversion connection adapter 91. In this way, in the trough connection structure 90b, the female joint structure 57a formed in the opening 49 at one end of the bent trough 41 is connected to the female joint structure 23a, 23b of at least one opening 15a, 15b of the approximately T-shaped branch trough via the male / female conversion connection adapter 91. In addition, the male-male conversion connection adapter 91 may be configured to fit two opposing female joint structures into a cutout portion in the center of a cross section of an approximately U-shaped configuration in which the outer sides of the approximately U-shaped, approximately parallel, straight portions are open outward.

[0130] Next, we will explain another trough connection structure using the branch trough 1. Figures 20A and 20B are diagrams showing a connection process of a connection structure (trough connection structure 90c) between a branch trough 1 having a substantially T-shape and a small-diameter trough 87.

[0131] The small-diameter trough 87, like the linear trough 81 described above, is a linear trough with approximately the same cross-sectional shape, and has a male joint structure 83a at one end and a female joint structure 85a at the other end. As described above, small-diameter troughs 87 can be connected to each other by linking their male joint structures 83a and female joint structures 85a. On the other hand, the small-diameter trough 87 has a smaller width and height than the linear trough 81. For this reason, the female joint structure 23a of the branching trough 1 cannot be directly connected to the male joint structure 83a of the small-diameter trough 87.

[0132] Therefore, in this embodiment, an end plate 93 is used. Figure 21A is a front view of the end plate 93. The end plate 93 is generally U-shaped, with an opening 95 of a predetermined size (width B in the figure) formed at either the top or bottom. On the other hand, as shown in Figure 21B, the male joint structure 83a of the small diameter trough 87 has a flange portion with a width D at its tip, and the width at its rear end is configured as width C, which is smaller than the flange portion width D. In this case, since the respective dimensions are configured as D > B > C, by inserting the end plate 93 into the width C portion of the male joint structure 83a of the small diameter trough 87, the flange portion of the wider male joint structure 83a is engaged by the end plate 93.

[0133] 20B , in the trough connection structure 90c, the male joint structure 83a of the small diameter trough 87 is disposed in the opening 95 of the end plate 93, and the flange portion of the male joint structure 83a of the small diameter trough 87 is fitted into the opening 95 of the end plate 93 as a retaining structure for connection. In this manner, the male joint structure 83a of the small diameter trough 87 is fixed to the end plate 93. Here, even if a pull-out force is applied to the small diameter trough 87, the male joint structure 83a abuts against the end plate 93, so that the small diameter trough 87 will not come off from the branch trough 1.

[0134] The end plate 93 has a rectangular shape wider than the distance between the opposing longitudinal ribs 21 of the female joint structures 23a, 23b of at least one opening 15a, 15b of the branch trough 1, which has a substantially T-shape. Therefore, when the end plate 93 is inserted between the longitudinal ribs of the female joint structures 23a, 23b, the end plate 93 is fixed to the female joint structures 23a, 23b. The end plate 93 preferably has a predetermined thickness so that, when placed in the female joint structure 23a of the opening 15a, the end plate 93 does not rotate obliquely from the opening 15a. Even if the end plate has an opening at the bottom center as shown in FIG. 21A , it is preferable that protrusions be formed at the lower ends on both sides of the opening so that the protrusions can fit into grooves 31 formed in the female joint structures 23a, 23b of the branch trough 1, as described below. In this way, by fitting the end plate into the groove of the female joint structure, it is possible to prevent the end plate from rotating in an oblique direction.

[0135] Next, a description will be given of a connection structure with a conduit, which is another cable protection member, using the branch trough 1. Figures 22A and 22B are diagrams showing a connection process of a substantially T-shaped branch trough and a conduit connection structure (trough connection structure 90d).

[0136] In this embodiment, the conduit connected to the branching trough 1 is a rectangular conduit 101 having an independent wave structure. The rectangular conduit 101 has large diameter sections 103 with rectangular cross sections and small diameter sections 105 with circular cross sections formed alternately. An end plate 93a having a split structure and capable of being separated into upper and lower halves is disposed in the female joint structures 23a, 23b of either opening 15a, 15b of the branching trough 1 having a substantially T-shape.

[0137] FIG. 23A is a front view of the end plate 93a. As described above, the end plate 93a can be divided into upper and lower halves, and openings 95a are formed at the opposing positions when the end plates 93a are divided. In the illustrated example, the openings 95a are semicircular, and when the divided end plates 93a are butted together, the openings 95a are substantially circular. It is desirable that the end plate 93a has a predetermined thickness so that, when placed in the female joint structure 23a of the opening 15a, the end plate 93a does not rotate obliquely from the opening 15a. As described below, the end plate preferably has a protrusion formed at its lower end, and the protrusion is desirably capable of fitting into the grooves 31 formed in the female joint structures 23a and 23b of the branch trough 1. In this way, fitting the end plate into the groove of the female joint structure also prevents the end plate from rotating obliquely.

[0138] The inner diameter of the substantially circular opening 95a formed at this time is slightly larger than the outer diameter of the small diameter portion 105 of the rectangular electric conduit 101 and smaller than the outer diameter (length of each side) of the large diameter portion 103 of the rectangular electric conduit 101. Therefore, as shown in Fig. 23B , the small diameter portion 105 of the rectangular electric conduit 101 is sandwiched between the opening 95a of the end plate 93a, thereby fixing the rectangular electric conduit 101 to the end plate 93a. Here, even if a pulling force is applied to the rectangular electric conduit 101, the large diameter portion 103 abuts against the end plate 93a, so that the rectangular electric conduit 101 will not come out of the branching trough 1. Note that the number of electric conduits fixed to one end plate 93a does not necessarily have to be one, and two or more may be used.

[0139] Furthermore, the conduit having independent waves is not limited to the rectangular conduit 101. Fig. 24A is a diagram showing a trough connection structure 90e in which a branching trough 1 and an independent-wave conduit 101a are connected. The independent-wave conduit 101a is similar to the rectangular conduit 101 in that large-diameter portions 103 and small-diameter portions 105 are formed alternately, but the cross-sectional shape of the large-diameter portions 103 is circular rather than rectangular. That is, in the independent-wave conduit 101a, both the large-diameter portions 103 and the small-diameter portions 105 have circular cross sections.

[0140] The inner diameter of the substantially circular opening 95a formed in the end plate 93a is slightly larger than the outer diameter of the small diameter portion 105 of the independent wave conduit 101a and smaller than the outer diameter of the large diameter portion 103 of the independent wave conduit 101a. Therefore, as shown in Fig. 24B , the small diameter portion 105 of the independent wave conduit 101a is sandwiched between the opening 95a of the end plate 93a, thereby fixing the independent wave conduit 101a to the end plate 93a. Even if a pulling force is applied to the independent wave conduit 101a, the large diameter portion 103 abuts against the end plate 93a, preventing the independent wave conduit 101a from coming out of the branching trough 1. In this way, in the trough connection structures 90d and 90e, the rectangular conduit 101 or the independent wave conduit 101a is fixed to the opening 95a of the end plate 93a, and the end plate 93a is fixed to the female joint structure of the branching trough 1, thereby connecting the branching trough 1 and the conduit.

[0141] Next, we will explain another trough connection structure using the branching trough 1. Figures 25A to 25C are diagrams showing a method for fixing an inner connection member 97a and an outer connection member 97b to the end of a helical wave conduit 101b. In this embodiment, the conduit connected to the branching trough 1 having a substantially T-shape is a helical wave conduit 101b having a circular cross-section and a helical wave structure.

[0142] The inner connection member 97a has a cylindrical portion 107a with a circular cross section and a helical groove formed on its outer peripheral surface so that the helical groove can fit into the helical shape of the inner peripheral surface of the helical wave conduit 101b, and a flange portion 109a formed at the end of the cylindrical portion 107a and having an enlarged diameter. The outer connection member 97b has a cylindrical portion 107b with a circular cross section and a helical groove formed on its inner peripheral surface so that the helical groove can fit into the helical shape of the outer peripheral surface of the helical wave conduit 101b, and a flange portion 109b formed at the end of the cylindrical portion 107b and having an enlarged diameter.

[0143] First, as shown in FIG. 25B , the outer connection member 97b is attached to the end of the helical wave conduit 101b. That is, the helical waves on the inner peripheral surface of the tubular portion 107b of the outer connection member 97b are screwed onto the helical waves on the outer peripheral surface of the helical wave conduit 101b. Next, as shown in FIG. 25C , the inner connection member 97a is attached to the end of the helical wave conduit 101b. That is, the helical waves on the outer peripheral surface of the tubular portion 107a of the inner connection member 97a are screwed onto the helical waves on the inner peripheral surface of the helical wave conduit 101b. In this way, the tubular portions 107a, 107b of the inner connection member 97a and the outer connection member 97b are screwed onto the inner peripheral surface and outer peripheral surface of the helical wave conduit 101b, respectively, and the inner connection member 97a and the outer connection member 97b are attached to the end of the helical wave conduit 101b.

[0144] Here, the outer connection member 97b is positioned further back from the end of the helical wave conduit 101b than the inner connection member 97a. A gap is formed between the flange portion 109b of the outer connection member 97b and the flange portion 109a of the inner connection member 97a. For example, when the tubular portion 107a of the inner connection member 97a is completely screwed into the helical wave conduit 101b, the size of the gap between the flange portion 109b of the outer connection member 97b and the flange portion 109a of the inner connection member 97a can be adjusted by rotating the tubular portion 107b of the outer connection member 97b around the outer circumference of the helical wave conduit 101b.

[0145] 26 is a diagram showing a connection structure (trough connection structure 90f) between a branch trough 1 having a substantially T-shape and a helical wave conduit. An end plate 93a having an opening 95a through which the conduit can be inserted is disposed in the female joint structure 23a of the opening 15a of the branch trough 1. The inner diameter of the substantially circular opening 95a formed in the end plate 93a is slightly larger than the outer diameter of the helical wave conduit 101b and smaller than the outer diameters of the flange portion 109b of the outer connection member 97b and the flange portion 109a of the inner connection member 97a. Therefore, the end plate 93a is sandwiched between the flange portion 109a of the inner connection member 97a and the flange portion 109b of the outer connection member 97b, thereby fixing the helical wave conduit 101b to the end plate 93a.

[0146] In this way, in the trough connection structure 90f, the inner connection member 97a and the outer connection member 97b are fixed to the end of the helical wave conduit 101b. Furthermore, the helical wave conduit 101b is disposed in the opening 95a of the end plate 93a, and the end plate 93a is sandwiched between the flange portion 109a of the inner connection member 97a and the flange portion 109b of the outer connection member 97b fixed to the helical wave conduit 101b and fixed to the branch trough 1. Therefore, even if a pull-out force is applied to the end plate 93a, the helical wave conduit 101b will not come out of the female joint structure 23a of the branch trough 1. Furthermore, the branch trough 1 and the helical wave conduit 101b are connected by fixing the end plate 93a to the female joint structures 23a, 23b of the branch trough 1.

[0147] As described above, each conduit and each trough may be connected to either opening 15a or opening 15b of branching trough 1 having a substantially T-shape. When end plate 93a is used, an end plate 93b as shown in Fig. 27 may be used instead of end plate 93a so as to be more reliably fixed to female joint structures 23a, 23b.

[0148] The end plate 93b has substantially the same structure as the end plate 93a, but a protrusion 99 is formed at the bottom tip of the lower end plate 93b. As described above, a groove 31 having a predetermined length in the width direction of the trough is formed approximately at the center of the bottom surface of the female joint structures 23a, 23b of the branching trough 1. Furthermore, a groove 63 having a predetermined length in the width direction of the trough is formed approximately at the center of the bottom surface of the female joint structure 57a of the curved trough 41. The protrusion 99 of the end plate 93b can be fitted into the groove 31 formed in the female joint structures 23a, 23b of the branching trough 1 and the groove 63 formed in the female joint structure 57a of the curved trough 41.

[0149] In this way, by fitting the protrusions 99 of the end plate 93b into the grooves 31 and 63, the end plate 93b can be more reliably fixed to each trough, and for example, rotation of the end plate 93b in an oblique direction can be prevented. Note that the same effect can be obtained by forming the protrusions 99 on the downward side of the end plate 93 that is open upward.

[0150] As described above, by using the method of connecting the straight trough 81, the curved trough 41, the small diameter trough 87, and each electrical conduit (which may be collectively referred to as simply cable protection members) to the branching trough 1 having an approximately T-shape, a connection structure between the branching trough 1 and various cable protection members can be obtained.

[0151] More specifically, at the three openings 15a, 15b of the branching trough 1, vertical ribs 21 of a predetermined height extend inward from the side plate 7 in a vertical direction facing each other at the ends of the openings 15a, 15b and at positions a predetermined distance away from the ends of the openings 15a, 15b near the ends of the openings 15a, 15b, forming a pair of approximately U-shaped female joint structures 23a, 23b. In this case, in the female joint structures 23a, 23b formed at the end of at least one of the three openings 15a, 15b of the branching trough 1, the flange portion of the male joint structure of the trough can be fixed directly to the space in which both end faces formed by the vertical ribs 21 are approximately parallel, or the female joint structure of the trough can be fixed via the male-male conversion connection adapter 91, or the small diameter portion flange portion of the male joint structure of the small diameter 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 can be sandwiched between the end plate, or the helical wave conduit can be fixed by screwing the inner connecting member 97a and the outer connecting member 97b to the end of the helical wave conduit via the end plate and sandwiching the end plate between the flange portion 109a of the inner connecting member 97a and the flange portion 109b of the outer connecting member 97b.

[0152] Here, in the present invention, the curved trough 41 also has female joint structures 57a, 57b that use the same vertical ribs 55 as the branching trough 1, so that, similar to the branching trough 1, the curved trough 41 can also have a connection structure between the curved trough 41 and various cable protection members, such as the male joint structure 83 of the straight trough 81, the male joint structure 83 of the straight trough 81, the female joint structure 85 of the straight trough 81 via the male-male conversion connection adapter 91, the small diameter trough 87 via any of the end plates 93, 93a, 93b, and each of the conduits (rectangular conduit 101, independent wave conduit 101a, helical wave conduit 101b).

[0153] Next, a trough line using a branch trough connection structure will be described. Fig. 28A is a diagram showing a trough line 100. The trough line 100 is configured by connecting a plurality of linear troughs 81 to a branch trough 1 having a substantially T-shape. For example, a trough line in which a plurality of linear troughs 81 of a predetermined length are connected is connected to openings 15a at both ends of the main trunk 9 of the branch trough 1 and another opening 15b provided in the branch section 11. As described above, adjacent linear troughs 81 are connected to each other by connecting their male joint structures 83 and female joint structures 85 (see Fig. 15A, etc.) to form a linear trough line.

[0154] As shown, the female joint structure 23b of the opening 15b is connected to a male joint structure 83 arranged at one end of the connecting structure of multiple connected linear troughs 81. Note that the female joint structure 23b of the opening 15b may be connected to a female joint structure 85 arranged at the other end of the connecting structure of multiple connected linear troughs 81 via a male-male conversion connection adapter 91.

[0155] Cables 115 are laid inside the trough track 100. Here, the cables 115 are arranged to have either a branched structure or a bent structure inside the branching trough 1. After all the cables 115 have been laid, as shown in Fig. 28B, the branching trough 1 is covered with a trough cover 3, and the linear trough 81 is covered with a trough cover 111.

[0156] Next, another trough line will be described. Fig. 29A is a diagram showing a trough line 100a. The trough line 100a is substantially similar to the trough line 100, but differs in that a curved trough 41 is used in part.

[0157] As described above, in the trough line 100a, multiple linear troughs 81 are connected to the openings 15a, 15b of the branch trough 1. That is, the trough line 100a has either a connection structure of linear troughs 81 with a male joint structure 83 disposed at one end, or a connection structure of linear troughs 81 with a female joint structure 85 disposed at the other end. In at least a portion of this trough line, curved troughs 41 having female joint structures 57a at both ends are disposed via male-male conversion connection adapters 91.

[0158] In the trough line 100a, the cable 115 is arranged to have either a branch structure or a bent structure inside the branch trough 1. In this state, as shown in Fig. 29B, the branch trough 1 is covered with a trough cover 3, the straight trough 81 is covered with a trough cover 111, and the bent trough 41 is covered with a trough cover 43.

[0159] 30A is a diagram showing yet another trough line 100b. The trough line 100b is substantially the same as the trough line 100, but differs in that a shielding plate 113 is disposed at one opening 15a of the branching trough 1.

[0160] In the trough line 100b, a plurality of linear troughs 81 are connected to one opening 15a of the main trunk 9 of the branching trough 1 and to the opening 15b of the branching section 11 (see FIG. 1, etc.). The male joint structures 83 of the linear troughs 81 may be directly connected to the female joint structures 23a, 23b of the branching trough 1, or the female joint structures 85 of the linear troughs 81 may be connected to the female joint structures 23a, 23b of the branching trough 1 via a male-male conversion connection adapter 91 (see FIG. 17A, etc.).

[0161] 31 is an enlarged view of the vicinity of the other opening 15a of the main trunk 9 of the branching trough 1 (the opening 15a on the opposite side from the opening 15a to which the multiple linear troughs 81 are connected). A shielding plate 113 is disposed in the female joint structure 23a of the other opening 15a of the main trunk 9 of the branching trough 1. The shielding plate 113 is a plate-like member that does not have an opening like the end plate described above. By fitting the shielding plate 113 into the space between the vertical ribs of the female joint structure 23a, the opening 15a on one end side of the branching trough 1 can be blocked.

[0162] The cables 115 arranged in each trough forming such a trough line 100b have only a bent structure within the branch trough 1. That is, the cables 115 are arranged on one side of the opposing openings 15a, and the shielding plate 113 is arranged on the other side, and the cables 115 are inserted through the openings 15b of the remaining branch section 11. In the trough line 100b as well, each trough is covered with a trough cover (not shown).

[0163] 30B is a diagram showing yet another trough line 100c. The trough line 100c is substantially the same as the trough line 100a, but differs from the trough line 100b in that a shielding plate 113 is disposed at one opening 15a of the branch trough 1.

[0164] Similar to the trough line 100b, the cables 115 arranged in each trough forming the trough line 100c only have a bent structure within the branch trough 1. That is, the cables 115 are arranged on one side of the mutually opposing openings 15a of the branch troughs 1 and on the opening 15b of the branch section 11, and the shielding plate 113 is arranged on the other side of the mutually opposing openings 15a of the branch troughs 1. Note that in the trough line 100c as well, each trough is covered with a trough cover (not shown).

[0165] As described above, according to this embodiment, the back surface of the bottom plate 5 of the branch trough 1 is provided with hollow columnar protrusions 27 that protrude downward from the bottom surface and have a hollow interior, and can be used as a bolt fixing structure, and since the bottom plate 5 is held at a predetermined height above the ground surface, it can be fixed with anchor bolts 37 to not only ordinary gravel surfaces and the ground, but also to road surfaces such as asphalt and concrete, and inclined surfaces. Furthermore, when fixing the branch trough 1 with anchor bolts 37, providing the hollow columnar protrusions 27 makes it possible to avoid stress concentration on the bottom plate 5.

[0166] Furthermore, the hollow columnar protrusions 27, which are hollow inside, are provided on the back surface of the bottom plate 5, thereby reinforcing the bottom plate 5. This allows the thickness of the bottom plate 5 of the branching trough 1 to be reduced, thereby achieving a reduction in the weight of the branching trough 1.

[0167] In this case, the presence of the thin bottom plate 5 on the top of the hollow columnar protrusion 27 makes it possible to make the height of the cable storage section of the other troughs connected to the branching trough 1 approximately the same. For example, when taking into consideration the ease of pulling in the cable, the bottom plate 5 can be provided at a position slightly higher than the ground surface 33, so that the height can be made approximately the same as the bottom plate of each trough connected to it, resulting in excellent ease of pulling in the cable.

[0168] Even when the hollow columnar protrusion 27 is not used as a bolt fixing structure, it can also be used as a drainage hole for the branch trough 1 by removing the shielding portion 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.

[0169] Furthermore, by providing protruding feet 25 on the back surface of the branch trough 1, the bottom plate 5 can be positioned at a predetermined height from the ground surface 33. In this way, by separating the bottom plate 5 from the ground surface 33 by a predetermined distance, even if the ground surface 33 is uneven, it is possible to avoid interference between the unevenness of the ground surface 33 and the branch trough 1. In this way, a predetermined space is created between the back surface of the bottom plate 5 and the ground surface 33, so that the branch trough 1 is less susceptible to the condition of the ground surface 33 and can also be fixed to road surfaces such as asphalt and concrete, and to inclined surfaces.

[0170] Furthermore, by providing the side plates 7 of the branching trough 1 with bent portions 17 to form a bent structure, the side plates 7 can be reinforced. Furthermore, by providing horizontal ribs 19 to connect the bent portions 17 of the side plates 7, both ends of the bent portions 17 can be supported by the horizontal ribs 19, and the bent portions 17 of the side plates 7 can be further reinforced by the horizontal ribs 19. Furthermore, both ends of the bent portions 17 have the effect of reinforcing the side plates 7 as vertical ribs 21 that are perpendicular to the bending direction of the bent portions of the side plates 7 on the outer periphery of the branching trough 1. Therefore, the overall structural strength can be maintained even if the thickness of the side plates 7 is not particularly large. Since the vertical ribs of the bending portion 17 of the branching trough 1 also serve as the approximately parallel inner vertical ribs of the U-shaped female joint structures 23a, 23b, it is only necessary to provide outer vertical ribs of the female joint structures 23a, 23b, and there is no need to provide vertical ribs on the outside of the bending portion of the branching portion 11 of the side plate 7.

[0171] In addition, by using the horizontal rib 19 as a fixing part of the fixing bracket for fixing the trough lid 3 to the top of the branching trough 1, the trough lid 3 can be easily fixed when placing the trough lid 3 on the branching trough 1.

[0172] As described above, the branching trough 1 is generally T-shaped and comprises a linear main trunk 9 and a branching section 11, with openings 15a provided at both ends of the linear main trunk 9 and openings 15b provided at the ends of the branching sections 11 branching off from the main trunk 9, in a direction perpendicular to the main trunk 9. The openings 15a and 15b provided in the branching trough 1 are formed with female joint structures 23a and 23b, which are a pair of opposing, generally parallel U-shaped rib structures extending inward at a predetermined height from the side plate 7. The female joint structures 23a and 23b provided in the openings 15a and 15b enable connection to the male joint structures of other troughs or to the female joint structures of other linear troughs, curved troughs, etc. via the male-male conversion connection adapter 91, making it possible to form a trough line connected to various troughs.

[0173] Furthermore, the female joint structures 23a, 23b are composed of opposing side plates 7, two parallel vertical ribs 21 sandwiching them, and a bottom plate 5 formed to connect the two. Furthermore, both ends of the bent portion 17 are the inner vertical ribs 21 of the female joint structures 23a, 23b provided in the openings 15a, 15b which are substantially U-shaped in plan view, and therefore not only do they serve as the vertical ribs 21 serving as the reinforcing structure described above, but also as the vertical ribs 21 that form the mating portions of the female joint structures 23a, 23b. Therefore, there is no need to provide any additional vertical ribs other than the outer vertical ribs 21 of the female joint structures 23a, 23b.

[0174] Furthermore, by providing end plates 93 or the like on the female joint structures 23a, 23b of the openings 15a, 15b, it is possible to form a connection structure in which not only the normal linear trough 81 but also various types of conduits, such as a small-diameter trough 87 with a small cross-sectional dimension, a rectangular conduit 101 with an independent wave structure, an independent wave conduit 101a, and a helical wave conduit 101b with a helical wave structure, are connected to the branch trough 1 via the end plates 93 or the like. In this case, the female joint structures 23a, 23b need to have dimensions and shapes that can accommodate all connection structures so that the troughs to be connected and the small-diameter portions of the conduits can be stably connected.

[0175] Furthermore, shallow grooves 31 having a predetermined length in the width direction of branch trough 1 are formed approximately at the centers of the bottoms of mutually opposing, approximately U-shaped female joint structures 23a, 23b, thereby efficiently fixing end plate 93b having protrusions 99 and preventing end plate 93b from rotating diagonally. In this way, by providing grooves 31 in the bottom plates 5 of female joint structures 23a, 23b and using end plate 93b, they can be used for fixing structures for a variety of troughs, electrical conduits, etc., in addition to connection structures using ordinary female joint structures 23a, 23b.

[0176] In this way, various trough lines can be constructed by connecting other troughs or various types of electrical conduits to the openings 15a and 15b of the branching trough 1. In this case, a branch structure may be formed in which the cable 115 arranged in the branching trough 1 branches into the branching section 11 and the cable passing through the main trunk 9, or the cable 115 arranged in the branching trough 1 may have a bent structure in which it is bent from the main trunk 9 to the branching section 11, and a bent line in which a shielding plate 113 is arranged may be formed in the opening 15a of the main trunk 9 where the cable 115 is not arranged.

[0177] Furthermore, even in the case of the curved trough 41, since it has the same structure as the branching trough 1 described above, the curved trough 41 can also achieve the same effects as those of the branching trough 1 described above, such as the effect of providing a hollow columnar protrusion 27 on the back surface of the bottom plate 5, the reinforcing effect of the side plate 7 by providing a bending structure and horizontal ribs 19 on the side plate 7, the effect of doubling as the vertical rib 21 as a female joint structure, and the effect when fixing the branching trough 1 to a paved road surface or an inclined surface.

[0178] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not limited to the above-described embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas described in the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention.

[0179] For example, it goes without saying that the above-described embodiments can be combined with each other. Furthermore, the combination and number of troughs in each trough line can be set as appropriate.

[0180] DESCRIPTION OF SYMBOLS 1...Branch trough 3...Trough cover 5...Bottom plate 7...Side plate 9...Main section 11...Branch section 13...Bending section 15a, 15b...Opening 17...Bending section 19...Horizontal rib 21...Vertical rib 23a, 23b...Female joint structure 25...Foot section 27...Hollow columnar protrusion 29...Bottom reinforcing rib 31...Groove 33...Ground surface 35...Space 37...Anchor bolt 40...Branch trough fixing structure 40a...Bend trough fixing structure 41...Bend trough 43...Trough cover 45...Bottom plate 47...Side plate 49...Opening 51...Bend section 53...Horizontal rib 55...Vertical rib 57a, 57b...Female joint structure 59...Inner bent portion 61...Outer bent portion 63...Groove 65...Foot portion 67...Hollow column-shaped protrusion 69...Bottom reinforcing rib 71...Ground surface 73...Space 75...Anchor bolt 81...Straight trough 83, 83a...Male joint structure 85, 85a...Female joint structure 87...Small diameter trough 90, 90a, 90b, 90c, 90d, 90e, 90f...Trough connection structure 91...Male-male conversion connection adapter 93, 93a, 93b...End plate 95, 95a...Opening 97a...Inner connection member 97b...Outer connection member 99...Protrusion 100, 100a, 100b, 100c...Trough line DESCRIPTION OF SYMBOLS 101....Rectangular conduit 101a...Independent wave conduit 101b...Spiral wave conduit 103...Large diameter portion 105...Small diameter portion 107a, 107b...Cylindrical portion 109a, 109b...Flange portion 111...Trough cover 113...Shielding plate 115...Cable

Claims

1. A branching trough having a U-shaped cross section, comprising side plates forming both side surfaces and a bottom plate forming the bottom surface, with both side plates standing up to surround the bottom plate, wherein the bottom plate is roughly T-shaped in plan view, and is composed of a roughly rectangular main trunk and a branch section formed on one long side of the main trunk in a direction perpendicular to the longitudinal direction of the main trunk, gradually reducing in diameter in a roughly arc-like shape, the side plate being formed of a straight section formed on one long side of the main trunk and a curved section forming the outer edge of the branch section, which extends and reduces in diameter in a roughly arc-like shape, the end of the branch section and the openings at both longitudinal ends of the main trunk each have a female joint structure of similar structure, and the female joint structure is formed as a pair of roughly U-shapes facing each other in plan view, with roughly parallel vertical ribs spaced a predetermined distance from each other, A branching trough characterized in that a horizontal rib is formed on the upper part of the bent portion of the side plate, the horizontal rib also serving as a fixing bracket mounting portion for attaching a fixing bracket for attaching a lid, connecting the vertical ribs of each of the bent portions formed at a predetermined distance from each other, and no vertical rib is provided on the outside of the side plate of the approximately arc-shaped bent portion.

2. The branching trough described in claim 1, characterized in that the female joint structures formed at the openings at both ends of the main trunk are female joint structures formed so as to extend inward in a direction perpendicular to the straight portion of the side plate of the main trunk and the side plate of the curved portion, and further, the female joint structure formed at the opening at the tip of the branching portion is a female joint structure formed so as to extend inward in a direction perpendicular to the curved portion, and the bent portions formed in the main trunk and the branching portion are all formed so as to double as inner vertical ribs of the respective female joint structures provided at the ends of the openings of the main trunk and the branching portion.

3. The branching trough described in claim 1, characterized in that: the bottom plate surface of the female joint structure is formed at a predetermined height lower than the bottom plate surface of a portion other than the female joint structure; the foot portions of the side plates of the female joint structure are formed to protrude from the back surface of the bottom plate at a predetermined height, and the bottom plate is supported by the foot portions at a predetermined height above the ground surface, thereby forming a space on the back surface of the bottom plate; a hollow columnar protrusion is formed at a predetermined position in the space formed on the back surface of the main trunk portion and the branching portion, protruding downward from the bottom plate at a predetermined height; 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.

4. A branching trough as described in claim 2 or claim 3, characterized in that on the underside of the bottom plate of the branching trough, which has an approximately T-shape, a plurality of bottom reinforcing ribs of a predetermined length are formed parallel to each other, connecting the two, from positions each offset a predetermined distance from the longitudinal center of the straight side plates of the main trunk portion toward the opening of the branching portion which extends opposite them.

5. A curved trough having a U-shaped cross section, which is made up of side plates forming both side surfaces and a bottom plate constituting a bottom surface, with both side plates standing up to surround the bottom plate, wherein the bottom plate has a curved portion in a predetermined direction at a predetermined angle 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 stand up to form a curved portion having a substantially arc shape upward so as to surround the curved portion of the bottom plate, and a substantially U-shaped opening is formed at each end of the side plate, and approximately parallel vertical ribs spaced apart by a predetermined distance from each other are formed at the ends of the openings at both ends of the side plate and in the vicinity of the ends of the openings at both ends, extending inwardly in a direction perpendicular to the curved portion on both sides of the curved portion of each of the side plates, thereby forming a pair of approximately U-shaped female joint structures having the vertical ribs and facing each other in a plan view, The side plates of the inner curved portion and the outer curved portion have bent portions that also serve as vertical ribs protruding inwardly, each bent portion being formed at a predetermined distance from the other at a predetermined position near the opening and a predetermined position intermediate the bent portions, the upper portions of the bent portions that also serve as vertical ribs, each formed at a predetermined distance from the other at a predetermined position near the opening of the side plates and a predetermined position intermediate the bent portions, have horizontal ribs to which a fixing bracket for attaching a lid can be attached, connecting the vertical ribs together, the horizontal ribs of the outer curved portion being longer than the horizontal ribs of the inner curved portion, and no vertical ribs are provided on the outside of each of the side plates that form the inner curved portion and the outer curved portion.

6. A curved trough as described in claim 5, characterized in that 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 curved portion spaced a predetermined distance from one end of the curved portion and in the vicinity of the predetermined position in the middle of the curved portion, and the bent portion provided at the predetermined position in the vicinity of the opening also serves as an inner vertical rib of the female joint structure in the vicinity of the opening, and further the bent portion formed at the predetermined position in the middle of the curved portion also serves as an inner vertical rib of the another female joint structure.

7. A curved trough as described in claim 5, characterized in that the bottom plate surface of the female joint structure formed at least at both ends of the curved portion is formed at a predetermined height lower than the bottom plate surface of portions other than the female joint structure, the foot portions of the side plates of the female joint structure are formed to protrude from the back surface of the bottom plate at a predetermined height, and the bottom plate is supported by the foot portions at a predetermined height above the ground surface, thereby forming a space on the back surface of the bottom plate, a hollow columnar protrusion 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.

8. A curved trough as described in any one of claims 5 to 7, characterized in that the other female joint structure is formed at a predetermined position midway between one end of the curved portion formed at both ends of the trough and the other end spaced a predetermined distance from one end of the curved portion, and at a predetermined position in the vicinity thereof, and the outer vertical ribs of the other female joint structure are formed approximately 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, and the inner curved portion is formed perpendicular to the curve that forms the curved portion, and the outer surfaces of the vertical ribs of the outer curved portion are connected to each other, the inner curved portion being formed perpendicular to the curve that forms the curved portion, and the outer vertical ribs are cut along the vertical ribs to form a curved trough structure having a bending angle smaller than the bending angle before cutting.

9. A connection structure between a branching trough and a straight trough as described in claim 1, characterized in that the male joint structure of a straight trough of a predetermined length and having approximately the same cross-sectional dimensions of the trough body is connected to the female joint structure of at least one of the openings of the branching trough having an approximately T-shape.

10. A connection structure for a branching trough and a straight trough as described in claim 1, characterized in that the female joint structure of at least one of the openings of the branching trough having an approximately T-shape is connected to the female joint structure of a straight trough of a predetermined length and having approximately the same cross-sectional dimensions of the trough body via a male-male conversion connection adapter.

11. A connection structure between the branching trough described in claim 1 and the bent trough described in claim 3, characterized in that the female joint structure formed in an opening at one end of the bent trough is connected to the female joint structure of at least one opening of the branching trough having an approximately T-shape via a male-male conversion connection adapter.

12. A connection structure between a branching trough and a small diameter trough as described in claim 1, wherein a rectangular end panel wider than the distance between the opposing vertical ribs of the female joint structure is inserted into the female joint structure of at least one of the openings of the branching trough which has an approximately T-shape, the end panel 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 disposed in the opening of the end panel, and a flange portion of the male joint structure of the small diameter trough is fitted into the opening of the end panel as a slip-out prevention structure to connect the male joint structure of the small diameter trough to be fixed to the end panel.

13. A connection structure between a branching trough and an electric conduit as described in claim 1, wherein the electric conduit connected to the branching trough having an approximately T-shape has an independent wave structure, and the electric conduit 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 upper and lower halves is disposed in the female joint structure of the opening of either of the branching troughs having an approximately T-shape, the end plate has openings in opposing positions when divided, 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.

14. A connection structure between a branching trough and an electric conduit according to claim 1, wherein the electric conduit connected to the branching trough having a substantially T-shape is an electric conduit having a spiral wave structure with a circular cross section, and an inner connection member having a cylindrical portion with a circular cross section having a spiral groove that can be fitted into the inner peripheral surface of the electric conduit and a flange portion formed at the end of the cylindrical portion, and an outer connection member having a cylindrical portion with a circular cross section having a spiral groove that can be fitted into the outer peripheral surface of the electric conduit and a flange portion formed at the end of the cylindrical portion, the cylindrical portions of the inner connection member and the outer connection member are screwed respectively into the inner peripheral surface and outer peripheral surface of the electric conduit and attached to the end of the electric conduit, a connection structure for a branching trough, characterized in that the outer connection member is positioned further back from the end of the electric conduit than the inner connection 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 connection member and a flange portion of the outer connection member.

15. A connection structure for a branch trough as described in any one of claims 12 to 14, 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 the mutually opposing, approximately U-shaped female joint structures, and a protrusion capable of fitting into the groove is provided at the bottom tip of the end plate.

16. A trough line using the connection structure of a branching trough as described in any one of claims 9 to 14, wherein a trough line having a plurality of linear troughs of a predetermined length connected to it is connected to the other opening of the branching trough having an approximately T-shape, and a male joint structure arranged at one end of the connection structure of the plurality of connected linear troughs is connected to the female joint structure of the other opening, or a female joint structure arranged at the other end of the connection structure of the plurality of connected linear troughs is connected via a male-male conversion connection adapter, and a cable is arranged inside the branching trough to have either a branch structure or a bent structure, and further covered with a trough cover.

17. A trough line as described in claim 16, characterized in that in at least a portion of a trough line having either a straight trough connecting structure with a male joint structure at one end or a straight trough connecting structure with a female joint structure at the other end, a bent trough having female joint structures at both ends is arranged via a male-male conversion connection adapter, and inside the branching trough, the cable is arranged to have either a branch structure or a bent structure, and further a trough cover is placed on top.

18. A trough line as described in claim 16, characterized in that the cable arranged in the trough forming the trough line has only a bent structure within the branching trough, and further, the cable is arranged on one side of the mutually opposing openings and a shielding plate is arranged on the other side, and the cable is inserted through the opening of the remaining branch section.

19. A trough line as described in claim 17, characterized in that the cables arranged in the troughs forming the trough line have only a bent structure in the branching trough, and further, cables are arranged on one side of the openings of the branching troughs that face each other and at the opening of the branching section, and a shielding plate is arranged on the other side of the openings of the branching troughs that face each other.

20. A fixing structure for a branch trough as described in claim 3, wherein 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 at a predetermined position approximately in the vicinity of the center of the boundary between the main trunk portion and the branch portion, the hollow columnar protrusion has a hollow cylindrical structure, and by inserting and tightening an anchor bolt into the hollow portion of the hollow cylindrical structure, the branch trough having an approximately T-shape is fixed to the asphalt or concrete ground.

21. A fixing structure for a curved trough as described in claim 7, characterized in that the hollow columnar protrusion that protrudes 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.

22. A method for connecting a cable protection member to a branching trough as described in claim 1, comprising the steps of: forming the female joint structure in which the vertical ribs of a predetermined height extend inwardly and perpendicularly from the side plate so as to be mutually opposed and generally parallel to each other at the end of at least one of the three openings of the branching trough and at a position adjacent to the end of the opening and spaced a predetermined distance from the end of the opening; A method for connecting a cable protection member to a branching trough, comprising the steps of directly fixing a flange portion of the male joint structure of the trough to a space formed by the vertical ribs in which both end faces are approximately parallel, fixing a female joint structure of the trough via a male-male conversion connection adapter, fixing a flange portion of the male joint structure of a small diameter trough via an end plate, fixing by sandwiching a small diameter portion of an independent wave conduit having a circular or rectangular cross section between the end plate, or fixing by screwing an inner connecting member and an outer connecting member to the end of a helical wave conduit via an end plate and sandwiching the end plate between the flange portion of the inner connecting member and the flange portion of the outer connecting member.

Images