Inner lid-type trough, processing method therefor, inner lid-type trough connection structure, and fixing method of trough body and trough lid in connection structure
Patent Information
- Application Number
- PCT/JP2025/043570
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-27
- Filing Date
- 2025-12-12
- Publication Date
- 2026-10-01
Smart Images
Figure JP2025043570_01102026_PF_FP_ABST
Abstract
Description
Drop-lid trough, processing method therefor, connecting structure of drop-lid trough, and method for fixing trough body and trough lid in the connecting structure
[0001] The present invention relates to a drop-lid trough in which a trough lid is arranged at a portion surrounded by side walls of a trough body, a processing method therefor, and further a connecting structure of a drop-lid trough using the same and a method for fixing the trough body and the trough lid in the connecting structure.
[0002] In a trough that accommodates cables therein, as a structure for attaching a trough lid to a trough body, besides the so-called external type in which the trough lid is placed on the upper surface of the side wall of the trough body, there is a so-called drop-lid trough (inner lid type trough) in which the trough lid is placed at a portion surrounded by the side wall of the trough body (for example, Patent Document 1).
[0003] DE197 25 976A1
[0004] The external type trough is applied, for example, when the trough is directly laid on the ground or laid by laying gravel or the like on the ground. In this case, since there is a space on the side of the trough body, a method using the space on the side of the trough body is often adopted as a method for fixing the trough lid to the trough body. For example, methods have been proposed: one in which a buckle is arranged on the outer surface of the trough body to fix the trough lid to the trough body by the buckle, and another in which a fixing fitting is fitted from above the trough lid to fix the fixing fitting to the outer surface of the trough body.
[0005] On the other hand, in a drop-lid trough, the trough lid is installed so as to be internally fitted on the side wall of the trough body. Since the portion where the trough lid is installed is surrounded by the side walls, the trough body may be embedded in the ground for use. In this case, for example, the trough lid is placed on a lid mounting portion inside the side wall of the trough body, and the trough lid is fixed to the trough body with hinges, bolts, or the like. As described above, in order to fix the trough lid to the trough body in a drop-lid trough, a buckle or a fixing band cannot be attached to the outer surface of the trough body, and the trough lid can only be attached to the trough body from above.
[0006] On the other hand, in a drop-lid type trough, because the trough cover is sandwiched between the side walls of the trough body, there is a risk that rainwater and sand may flow into the interior of the trough body through the gap between the trough cover and the side walls of the trough body. If water enters the interior of the trough body, it can cause, for example, deterioration of the insulation of internal cables, corrosion, and the formation of electrical short circuits. In addition, the accumulation of sand and other materials inside the trough body can cause damage to various structures and lead to poor drainage and ventilation of the trough body. For this reason, regular maintenance such as cleaning out water and sand was necessary.
[0007] This invention has been made in view of these problems, and aims to provide a drop-lid type trough, etc., that can prevent sand and water from flowing into the inside of the trough body.
[0008] To achieve the aforementioned objective, the first invention is a drop-lid type trough comprising a trough body having a bottom plate portion and side wall portions erected on both sides of the bottom plate portion, and a trough cover placed on the upper part of the trough body, wherein the trough cover is fixed in a position sandwiched between the side wall portions on both sides, wherein the side wall portion comprises a cover mounting portion on which the trough cover is placed, an upper side wall portion erected above the cover mounting portion, and a lower side wall portion formed below the cover mounting portion, wherein when the trough cover is placed on the cover mounting portion, the trough cover is positioned between the upper side wall portions on both sides, a recess is formed on the outer surface of the lower side wall portion, and a slit is formed in the cover mounting portion at the location where the recess is formed, connecting the space above the cover mounting portion with the external space of the trough body.
[0009] On the inner surface of the upper side wall portion, projections are formed that protrude in the opposing direction of the upper side wall portions on both sides, and when the trough cover is placed on the cover mounting portion, the trough cover may abut against and be sandwiched between the projections on both sides.
[0010] In this case, in a cross-section perpendicular to the longitudinal direction of the trough body, it is desirable that the width of the slit formed from the inner surface of the upper side wall toward the center of the trough body is greater than or equal to the protruding length of the projection from the inner surface of the upper side wall.
[0011] A pair of back projections protruding downward are formed on the back surface of the trough cover, and when the trough cover is placed on the cover mounting portion, both of the back projections may each abut against the inner surfaces of the opposing lower side walls.
[0012] In this case, in a cross section perpendicular to the longitudinal direction of the trough body, when the trough cover is placed on the cover mounting portion, it is desirable that the distance between the slits on both sides in the width direction is less than or equal to the width of the trough cover. Furthermore, multiple slits may be formed in the longitudinal direction of the trough body at predetermined lengths.
[0013] The trough cover may have a bolt receiving bracket, the bolt receiving bracket being fixed to the side wall at the position of the slit, and the trough cover being fixed to the bolt receiving bracket with bolts.
[0014] In this case, the bolt receiving fitting has a main body portion that is inserted into the slit, a nut portion formed on the upper part of the main body portion, and a locking claw formed on the lower end of the main body portion, wherein the locking claw is locked to a stepped portion formed on the outer surface of the lower side wall portion, and the bolt is fixed to the nut portion.
[0015] Below the upper side wall portion, an extended side wall portion is formed that extends further down than the lid mounting portion, and a space communicating with the slit may be formed between the extended side wall portion and the lower side wall portion.
[0016] According to the first invention, a slit is formed that connects the space above the lid mounting section on which the trough lid is placed with the external space of the trough body. As a result, water and sand that have fallen between the trough lid and the side walls can be discharged to the outside of the trough body through the slit. Therefore, the intrusion of foreign matter such as water and sand into the inside of the trough body can be suppressed.
[0017] Furthermore, by forming protrusions on the inner surface of the upper side wall, the trough cover can be positioned relative to the trough body by contacting and being sandwiched between the protrusions on both sides. As a result, the trough cover can be positioned approximately in the center of the width direction of the trough body, and the aforementioned slit can be prevented from being blocked by the trough cover.
[0018] In this case, by making the width of the slit formed from the inner surface of the upper side wall in a cross section perpendicular to the longitudinal direction of the trough body greater than or equal to the protruding length of the projection from the inner surface of the upper side wall, a slit is formed throughout the entire region between the trough cover and the upper side wall, thereby minimizing the area where sand and other debris can accumulate.
[0019] Furthermore, by forming a pair of downwardly projecting projections on the back surface of the trough cover, and ensuring that both projections abut against the inner surfaces of the opposing lower side walls, the trough cover can be positioned relative to the trough body. As a result, the trough cover can be positioned approximately in the center of the width direction of the trough body, preventing the aforementioned slit from being blocked by the trough cover.
[0020] In this case, by making the distance between the slits on both sides in the width direction in a cross section perpendicular to the longitudinal direction of the trough body less than or equal to the width of the trough cover, slits are formed throughout the entire area between the trough cover and the upper side wall, minimizing the area where sand and other materials can accumulate.
[0021] Furthermore, by forming multiple slits of predetermined length along the longitudinal direction of the trough body, it becomes possible to cut the trough body at any position and fix bolt receiving brackets to the slits adjacent to the cut position. Therefore, by fixing the bolt receiving brackets to the side wall at the position of the slits and fixing the trough cover to the bolt receiving brackets with bolts, the trough cover can be fixed to the trough body at any position in the slits.
[0022] In this case, the bolt receiving bracket can be easily attached to the trough body by engaging the locking claw formed on the lower end of the bolt receiving bracket with the stepped portion formed on the outer surface of the lower side wall. Furthermore, since the bolt receiving bracket can be slid along the slit, it becomes easy to align the nut portion of the bolt receiving bracket with the bolt hole of the trough cover.
[0023] Furthermore, by forming an extended side wall below the upper side wall, extending further down than the lid mounting section, a space communicating with the slit can be formed between the extended side wall and the lower side wall. As a result, the extended side wall can stably secure excess space below the slit, allowing sand and other materials from above to fall reliably into the space.
[0024] The second invention is a method for processing a drop-lid-shaped trough according to the first invention, characterized in that the trough body and the trough lid are each cut to a predetermined length, the cut trough lid is placed on the trough body, and the trough lid is fixed to the trough body with a fixing member.
[0025] The third invention is a connecting structure for a drop-lid-shaped trough according to the first invention, characterized in that the trough body has a female body connecting portion at one end and a male body connecting portion at the other end, the trough cover has an upper overlapping portion at one end and a lower overlapping portion at the other end, adjacent trough bodies are connected by their respective female body connecting portions and male body connecting portions, the trough cover is placed on one trough body and the other trough cover is placed on the other trough body, the upper overlapping portion of the other trough cover is placed on the lower overlapping portion of the trough cover, and the trough cover is fixed to the trough body by a fixing member using a fixing fitting attached near the female body connecting portion.
[0026] The trough body is cut to a predetermined length at the rib position of the lower side wall so as to include a predetermined number of slits from one end to the other end, and the trough cover is cut to a predetermined length that matches the trough body from the overlapping part on the cover side, or cut to a length shorter than the predetermined length by the length of the overlapping part on the cover, and the trough body cut to either length and the trough cover cut may be fixed together.
[0027] A bolt receiving bracket may be inserted into the slit of the trough body, the bolt receiving bracket may be fixed to the trough body, a bolt may be inserted from above into a bolt hole formed at a predetermined position corresponding to the slit, and the bolt may be tightened into the bolt receiving bracket.
[0028] The fourth invention is a method for fixing the trough body and trough cover in a connecting structure of drop-lid troughs when using a drop-lid trough according to the first invention, cutting one drop-lid trough and not cutting the other drop-lid trough, and connecting the two to each other, wherein one trough body has only a female body connecting portion at one end, and is cut to a predetermined length at the rib position of the lower side wall portion so as to include a predetermined number of slits from one end to the other end, and the cut rib is processed as a male body connecting portion, and the other trough body has a female body connecting portion at one end of the trough body and a male body connecting portion at the other end, and the connection between the trough bodies is made by connecting the female body connecting portion of the other uncut trough body to the main body of one trough body This method for fixing a trough body and trough cover in a trough connection structure is characterized by connecting rib sections processed as male body connecting sections, cutting one trough cover shorter than the length of the trough body cut by the length of the overlapping section on the adjacent trough cover, placing one end of the trough cover on one trough body so that it aligns with the end of the female body connecting section of the trough body, and placing the other trough cover on the other trough body so that the overlapping section on the cover contacts the cut end of the trough cover, and fixing each trough cover using fixing fittings fixed to each trough body and fixing members.
[0029] According to the second to fourth inventions, a stable trough connection structure can be obtained. Furthermore, the length of the drop-lid trough can be adjusted by cutting the trough body. In this case, by using a bolt receiving fitting that is locked to the stepped portion of the side wall, the trough lid can be securely fixed to the trough body even when the length of the trough lid is adjusted to match the length of the cut trough body. Similarly, for connection structures of cut and uncut troughs, the trough lid can be fixed to the trough body using fixing members such as bolts and nuts, thereby closing the opening at the top of the trough body.
[0030] According to the present invention, it is possible to provide a drop-lid-type trough, etc., that can prevent sand and water from flowing into the inside of the trough body.
[0031] An exploded perspective view showing the drop-lid trough 1. An assembled perspective view showing the drop-lid trough 1. A plan view of the trough body 3. A cross-sectional view taken along line A-A in Figure 3. A cross-sectional view taken along line B-B in Figure 3. A diagram showing the process of installing the trough cover 5 onto the trough body 3. A diagram showing the process of installing the trough cover 5 onto the trough body 3. An enlarged view showing the vicinity of the slit in the trough body 3. A plan view of the trough body 3a. A cross-sectional view taken along line I-I in Figure 7A. A diagram showing the process of installing the trough cover 5a onto the trough body 3a. A diagram showing the process of installing the trough cover 5a onto the trough body 3a. An enlarged view showing the vicinity of the slit in the trough body 3b. A diagram showing the process of installing the bolt receiving bracket 35 onto the trough body 3c. A diagram showing the process of installing the bolt receiving bracket 35 onto the trough body 3c. A plan view of Figure 10B. A diagram showing the process of installing the trough cover 5 onto the bolt receiving bracket 35. A diagram showing the process of installing the trough cover 5 onto the bolt receiving bracket 35. A side view showing the process of connecting the trough bodies 3c together. A side view showing the process of connecting the trough bodies 3c together. A plan view showing the process of connecting the trough bodies 3c together. A plan view showing the process of connecting the trough bodies 3c together. A side cross-sectional view showing the process of installing the trough cover 5 onto the connected trough bodies 3c. A side cross-sectional view showing the process of installing the trough cover 5 onto the connected trough bodies 3c. A plan view of Figure 14B. A side cross-sectional view showing the process of installing the trough cover 5 onto the connected trough bodies 3c. A side cross-sectional view showing the process of installing the trough cover 5 onto the connected trough bodies 3c. A plan view of Figure 15B. A diagram showing the process of cutting the trough body 3c to form a cut trough body 43. A diagram showing the process of cutting the trough body 3c to form a cut trough body 43. A diagram showing the process of cutting the trough body 3c to form a cut trough body 43. A diagram showing the process of cutting the trough cover 5 to form a cut trough cover 45. A diagram showing the process of cutting the trough cover 5 to form a cut trough cover 45. A diagram showing the process of cutting the trough cover 5 to form a cut trough cover 45. A diagram showing the process of connecting the cut trough body 43 and the trough body 3c. A diagram showing the process of connecting the cut trough body 43 and the trough body 3c. A diagram showing the process of connecting the cut trough body 43 and the trough body 3c. A side cross-sectional view showing the process of installing the cut trough cover 45 onto the connected cut trough body 43 and the trough body 3c. A side cross-sectional view showing the process of installing the cut trough cover 45 onto the connected cut trough body 43 and the trough body 3c. A plan view of Figure 19B.A side cross-sectional view showing the process of installing the trough cover 5 onto the connected cutting trough body 43 and trough body 3c. A side cross-sectional view showing the process of installing the trough cover 5 onto the connected cutting trough body 43 and trough body 3c. A plan view of Figure 20B. A diagram showing the state of use of the fixing bracket 25. A diagram showing the state of use of the fixing bracket 25a.
[0032] (First Embodiment) Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 is an exploded perspective view showing a drop-lid trough 1, and Figure 2 is an assembled perspective view showing a drop-lid trough 1. The drop-lid trough 1 consists of a trough body 3, a trough cover 5 placed on top of the trough body 3, etc. The drop-lid trough 1 is made of resin, for example, and is formed by press molding or injection molding.
[0033] The trough body 3 has a bottom plate portion 7 and side wall portions 9 erected on both sides of the bottom plate portion 7. The space above the bottom plate portion 7 of the trough body 3, enclosed by both side wall portions 9, serves as a space for accommodating cables and the like. The opposing direction of the pair of side wall portions 9 is defined as the width direction. That is, the pair of side wall portions 9 stand upright at the widthwise ends of the bottom plate portion 7. In the drop-lid type trough 1, the trough lid 5 is fixed in a position where it is sandwiched between the upper side wall portions 9c of the side wall portions 9 on both sides in the width direction.
[0034] A male connecting portion 11 is formed at one end of the trough body 3, and a female connecting portion 13 is formed at the other end. Figure 3 is a plan view of the trough body 3. The male connecting portion 11 has a projection that protrudes outward at its end, and the female connecting portion 13 has a groove that receives the projection of the male connecting portion 11. In other words, adjacent trough bodies 3 can be connected by fitting the projection of the male connecting portion 11 into the groove of the female connecting portion 13. The connection structure between the trough bodies will be described in detail later.
[0035] As shown in Figure 1, an overlapping portion 15a is formed at one end of the trough cover 5, and an overlapping portion 15b is formed at the other end. The overlapping portion 15a is a portion whose upper surface height is lower than that of the other parts. The lower side of the overlapping portion 15b has a space into which the thickness of the overlapping portion 15a can be inserted. In other words, when the trough cover 5 is installed together, the overlapping portion 15b can be placed on top of the overlapping portion 15a.
[0036] A fixing bracket 25 is attached to the end of the trough body 3 on the side of the female connecting portion 13. A nut is fixed to the fixing bracket 25, and a bolt 23 is tightened through the bolt hole 21 of the trough cover 5. In other words, the trough cover 5 is fixed to the trough body 3 by tightening the bolt 23 to the fixing bracket 25 attached to the trough body 3. Note that the fixing bracket 25 may also be attached to the end on the side of the male connecting portion 11.
[0037] The side wall portion 9 of the trough body 3 has a lid placement portion 9a, a lower side wall portion 9b, and an upper side wall portion 9c. The lid placement portion 9a is the portion on which the trough lid 5 is placed. That is, the lid placement portion 9a has a plane that is substantially parallel to the bottom plate portion 7. With respect to the width direction of the trough body 3, an upper side wall portion 9c is formed at the outer end of each lid placement portion 9a, rising above the lid placement portion 9a. That is, the lid placement portion 9a is formed inside the upper side wall portion 9c. Therefore, as shown in Figure 2, when the trough lid 5 is placed on the lid placement portion 9a, the trough lid 5 is positioned between the side wall portions 9 on both sides (upper side wall portion 9c).
[0038] The lid mounting portion 9a serves as the top surface, and below the lid mounting portion 9a, a lower side wall portion 9b is formed. Multiple ribs 17 are formed on the outer surface of the lower side wall portion 9b along the height direction. The ribs 17 are projections formed on the outer surface of the lower side wall portion 9b and are formed at predetermined intervals in the longitudinal direction of the trough body 3. That is, on the outer surface side of the lower side wall portion 9b, recesses 19 are formed between the ribs 17, with the outer surface being concave relative to the ribs 17. Multiple recesses 19 are arranged at predetermined intervals along the longitudinal direction of the trough body 3 via the ribs 17.
[0039] Figure 4A is a cross-sectional view taken along line A-A in Figure 3, and Figure 4B is a cross-sectional view taken along line B-B in Figure 3. As shown in Figures 3 and 4A, in the area where the recess 19 is formed, the lid mounting portion 9a has multiple slits 27 formed at predetermined intervals in the longitudinal direction of the trough, connecting the space above the lid mounting portion 9a with the external space of the trough body 3 (outside the recess 19). That is, the slits 27 penetrate the lid mounting portion 9a vertically from the inner surface of the upper side wall portion 9c to a predetermined position in the central direction in the width direction of the trough body 3.
[0040] On the other hand, as shown in Figure 4B, in the area where the rib 17 is formed, the slit 27 is not formed, and the lid mounting portion 9a has a flat surface. Therefore, the trough lid 5 can be installed on the lid mounting portion 9a.
[0041] Figure 5A shows the process of installing the trough cover 5 onto the trough body 3. The trough body 3 is placed, for example, in a groove formed in the ground 31. That is, the trough body 3 is embedded in the ground 31 up to near the upper part of the side wall 9.
[0042] A pair of back projections 29 are formed on the back surface of the trough cover 5, projecting downwards. In a cross-section perpendicular to the longitudinal direction of the trough cover 5, the back projections 29 are tapered so that their thickness decreases towards the lower end, with the outer surface of each back projection 29 (the surface opposite to the opposing surface) being tapered. That is, the distance between the outer surfaces of the opposing pair of back projections 29 (F in the figure) decreases towards the lower end of the back projection 29 due to the tapered shape.
[0043] Here, as shown in Figure 4A, in a cross-section perpendicular to the longitudinal direction of the trough body 3, the distance between the inner surfaces of the opposing upper side walls 9c is defined as C. Also, the distance between the slits 27 on both sides in the width direction (the distance between the inner surfaces of the slits 27) is defined as D. Furthermore, the opening width of the trough body 3 (the distance between the inner surfaces of the side walls 9) is defined as O. Also, as shown in Figure 5A, the width of the trough cover 5 is defined as E.
[0044] As described above, since the trough body 3 is buried in the ground, earth pressure (G in the figure) is applied from the outside of the side wall portion 9. For this reason, there is a possibility that the opening width (O in FIG. 4A) of the trough body 3 may be slightly reduced. Here, the outer surface width (F in FIG. 5A) of the back projection 29 is set to be substantially the same as or slightly smaller than the opening width (O in FIG. 4A) of the trough body 3 to such an extent that the back projection 29 can be inserted into the trough body 3.
[0045] For this reason, as shown in FIG. 5B, when the trough lid 5 is installed on the lid placement portion 9a from above the trough body 3, the tip end of the back projection 29 is inserted between the side wall portions 9 of the trough body 3. Further, by further pushing the trough lid 5 downward, the trough lid 5 is installed on the lid placement portion 9a while the side wall portion 9 of the trough body 3 is pushed open by the back projection 29 (H in the figure). That is, when the trough lid 5 is placed on the lid placement portion 9a, the outer surfaces of both back projections 29 respectively abut against the inner surfaces of the opposing side wall portions 9 (lower side wall portions 9b). By doing so, the trough lid 5 can be reliably arranged at the center in the width direction of the trough body 3.
[0046] At this time, the width of the trough lid 5 (E in FIG. 5A) is sufficiently smaller than the interval between the upper side wall portions 9c of the trough body 3 (C in FIG. 4A). For this reason, as shown in FIG. 5B, when the trough lid 5 is placed on the lid placement portion 9a in a cross section perpendicular to the longitudinal direction of the trough body 3, a gap is formed between the outer side surface of the trough lid 5 and the inner side surface of the upper side wall portion 9c. This gap serves as a falling path for water, sand and the like from above.
[0047] On the other hand, when the trough lid 5 is placed on the lid placement portion 9a in a cross section perpendicular to the longitudinal direction of the trough body 3, the distance between the slits 27 on both sides in the width direction (D in FIG. 4A) is equal to or less than the width of the trough lid 5 (E in FIG. 5A). For this reason, the inner side surface of the slit 27 (the end face on the center side in the width direction of the trough body 3) is always positioned overlapping with the lower surface of the trough lid 5. That is, in a cross section perpendicular to the longitudinal direction of the trough body 3 at the site where the slit 27 is formed, the flat surface of the lid placement portion 9a is not exposed in the gap between the trough lid 5 and the upper side wall portion 9c, and the slit 27 is exposed over the entire gap.
[0048] Fig. 6 is an enlarged view of the vicinity of the slit 27. As described above, water and sand fall from above into the gap between the trough cover 5 and the upper side wall 9c of the trough body 3. In contrast, the lower surface of the gap opens downward through the slit 27. Therefore, water and sand do not accumulate in the gap between the trough cover 5 and the upper side wall 9c of the trough body 3, and are discharged downward (to the outside of the trough body 3).
[0049] As described above, according to the first embodiment, by providing the slit 27 in the cover mounting portion 9a of the trough body 3, water, sand and the like falling onto the cover mounting portion 9a from above can be discharged to the outside of the lower recess 19 (outside the trough body 3) through the slit 27. Therefore, accumulation of sand or the like on the cover mounting portion 9a can be suppressed, and intrusion of foreign matters such as water and sand into the trough body 3 can be prevented.
[0050] Furthermore, since the trough cover 5 is arranged on the upper part of the trough body 3 by inserting the back projection 29 provided on the back surface of the trough cover 5 into the opening of the trough body 3, the back projection 29 can function as a guide for the trough body 3. Therefore, the trough cover 5 can be reliably arranged at the center in the width direction of the trough body 3, and the gap between the trough cover 5 and the upper side wall 9c can be kept constant.
[0051] Furthermore, by appropriately setting the width of the trough cover 5 and the formation range of the slit 27, the slit 27 can be reliably formed in the gap between the trough cover 5 and the upper side wall 9c. Therefore, water and sand from above can be reliably guided to the slit 27 and discharged below the trough body 3.
[0052] (Second Embodiment) Next, a second embodiment will be described. Fig. 7A is a plan view showing a trough body 3a according to the second embodiment, and Fig. 7B is a cross-sectional view taken along line I-I of Fig. 7A. In the following description, components having the same functions as those in the first embodiment are denoted by the same reference numerals as those in Figs. 1 to 6, and duplicate descriptions are omitted.
[0053] The trough body 3a has substantially the same configuration as the trough body 3, but differs in that projections 33 are formed on the inner surface of each upper side wall 9c on both sides in the width direction, projecting toward the opposing directions of the upper side wall 9c. The projections 33 are formed on the upper side wall 9c at positions corresponding to the ribs 17. Near the upper end of the projection 33, it takes on a tapered or arc shape so that the amount of protrusion from the upper side wall 9c gradually decreases as it approaches the upper end.
[0054] Here, as shown in Figure 7A, let J be the width of the slit 27 from the inner surface of the upper side wall portion 9c with respect to the width direction of the trough body 3a. Also, as shown in Figure 7B, let K be the amount of protrusion of the projection portion 33 from the inner surface of the upper side wall portion 9c.
[0055] Figure 8A shows the process of installing the trough cover 5a onto the trough body 3a. The trough cover 5a is substantially the same as the trough cover 5, but differs in that it does not require a protrusion on its back surface. The trough body 3a, like the trough body 3, is placed, for example, in a groove formed in the ground 31.
[0056] Here, as shown in Figure 8A, in a cross-section perpendicular to the longitudinal direction of the trough body 3a, the distance between opposing projections 33 is M, and the width of the trough cover 5a is L. As mentioned above, when the trough body 3a is buried in the ground, soil pressure (G in the figure) is applied from the outside of the side wall portion 9. As a result, the side wall portion 9 of the trough body 3a may deform slightly inward, and the distance M between opposing projections 33 may decrease. Here, the distance M between the projections 33 is set to be approximately the same as, or slightly larger than, the width L of the trough cover 5a, so that the trough cover 5a can be inserted between the projections 33.
[0057] Therefore, as shown in Figure 8B, when the trough cover 5a is installed on the cover mounting section 9a from above the trough body 3a, the trough cover 5a is inserted between the projections 33 of the trough body 3a. Furthermore, by pushing the trough cover 5a downwards, the trough cover 5a pushes open the projections 33 (side wall portions 9 of the trough body 3a) (N in the figure) as it is installed on the cover mounting section 9a. In other words, when the trough cover 5a is placed on the cover mounting section 9a, the trough cover 5a abuts against and is sandwiched between the projections 33 on both sides. In this way, the trough cover 5a can be reliably positioned in the center of the width direction of the trough body 3a.
[0058] In this case, in a cross section perpendicular to the longitudinal direction of the trough body 3a, when the trough cover 5a is placed on the cover mounting portion 9a, the width of the slit 27 formed from the inner surface of the upper side wall portion 9c toward the center of the trough body 3a (J in Figure 7A) is greater than or equal to the protruding length of the projection 33 from the inner surface of the upper side wall portion 9c (K in Figure 7B). Therefore, the inner surface of the slit 27 (the end surface on the center side in the width direction of the trough body 3a) is always in a position that coincides with the lower surface of the trough cover 5a. That is, in a cross section perpendicular to the longitudinal direction of the trough body 3 in the area where the slit 27 is formed, the flat surface of the cover mounting portion 9a is not exposed in the gap between the trough cover 5a and the upper side wall portion 9c, and the slit 27 is exposed throughout the entire gap. Therefore, the lower surface of the gap between the trough cover 5a and the upper side wall portion 9c is opened downward by the slit 27, allowing water and sand to be discharged downward without accumulating in the gap between the trough cover 5a and the upper side wall portion 9c.
[0059] According to the second invention, the same effects as the first invention can be obtained. Furthermore, by forming a projection 33 on the inner surface side of the upper side wall portion 9c, the same effects as forming a back surface projection 29 on the back surface of the trough cover 5a can be obtained.
[0060] (Third Embodiment) Next, a third embodiment will be described. Figure 9 is an enlarged view of the vicinity of the slit 27 in the trough body 3b according to the third embodiment. The trough body 3b has substantially the same configuration as the trough body 3, but differs in that an extended side wall portion 9d is provided below the upper side wall portion 9c. In the illustrated example, an example using a trough cover 5 having a back surface projection portion 29 is shown, but if a projection portion 33 is formed on the inner surface of the upper side wall portion 9c, it may be combined with a trough cover 5a.
[0061] The extended side wall portion 9d is formed by extending the upper side wall portion 9c downward from the lid mounting portion 9a. That is, the lower end of the extended side wall portion 9d is positioned lower than the upper end of the lower side wall portion 9b, and a space communicating with the slit 27 is formed between the extended side wall portion 9d and the lower side wall portion 9b for the length of the extended side wall portion 9d.
[0062] As mentioned above, since the trough body 3b is buried in the ground 31, soil and gravel are placed outside the side wall portion 9 of the trough body 3b. As a result, there is a risk that the lower part of the slit 27 will be filled with soil and gravel. If the lower part of the slit 27 is filled in this way, sand and other materials from above will not be discharged downwards and may accumulate inside the slit 27.
[0063] In contrast, in the trough body 3b, the extended side wall 9d functions as a retaining wall that prevents soil and other materials from collapsing towards the lower side wall 9b. This allows for the creation of a space below the slit 27 for discharging sand and other materials.
[0064] The third embodiment provides the same effects as the first embodiment. Furthermore, the extended side wall portion 9d secures a space for discharging sand and other materials, ensuring that sand and other materials are reliably discharged downwards from the slit 27. In this case, the provision of the extended side wall portion 9d secures an excess space below the slit 27, providing a space below the slit 27 for storing and accumulating water and sand that have passed through the slit 27. This makes it less likely for the slit 27 to become clogged.
[0065] (Fourth Embodiment) Next, a fourth embodiment will be described. This embodiment will be used, for example, in the sixth embodiment described later. Figure 10A shows the process of attaching the bolt receiving bracket 35 to the trough body 3c according to the fourth embodiment. The trough body 3c has substantially the same configuration as the trough body 3, but differs in that a stepped portion 34 is formed above the lower side wall portion 9b so that the lower side wall portion 9b bends toward the outer surface. That is, the width of the slit 27 is narrower than the width of the slit in the first to third embodiments described above, and a flat surface of the lid mounting portion 9a is formed inside the slit 27. For this reason, a flat surface substantially parallel to the lid mounting portion 9a is formed on the lower surface side of the lid mounting portion 9a.
[0066] The bolt receiving bracket 35 has a main body portion 37, a nut portion 41 formed on the upper part of the main body portion 37, and a locking claw 39 formed on the lower end of the main body portion 37. The roughly plate-shaped main body portion 37 is the part that is inserted into the slit 27. The upper part of the main body portion 37 is bent almost vertically, and the nut portion 41 is fixed to the bent portion facing upward.
[0067] As shown in Figure 10B, by inserting the main body portion 37 from above the slit 27, the locking claw 39 is locked to the stepped portion 34 formed on the outer surface of the lower side wall portion 9b. At this time, the nut portion 41 is positioned on the upper part of the lid mounting portion 9a. In this way, the bolt receiving bracket 35 is fixed to the side wall portion 9 at the position of the slit 27.
[0068] Furthermore, the bolt receiving bracket 35 only engages the locking claw 39 with the stepped portion 34. Therefore, as shown in Figure 10C, the bolt receiving bracket 35 can slide in the longitudinal direction of the trough body 3c within the range in which the slit 27 is formed. In other words, the position of the bolt receiving bracket 35 relative to the trough body 3c can be adjusted.
[0069] Figure 11A shows the process of attaching the trough cover 5 to the trough body 3c to which the bolt receiving bracket 35 is attached. Bolt holes 21a are formed in the trough cover 5. The bolt holes 21a can be formed at any position.
[0070] As shown in Figure 11B, the trough cover 5 is placed on the cover mounting portion 9a of the trough body 3c, and a bolt 23a is inserted through the bolt hole 21a from above the trough cover 5 and tightened into the nut portion 41. In this way, the trough cover 5 can be fixed to the bolt receiving bracket 35 with the bolt 23a. That is, the trough cover 5 can be fixed to the trough body 3c.
[0071] According to the fourth embodiment, the same effects as the first embodiment can be obtained. Furthermore, by using the bolt receiving bracket 35, the trough cover 5 can be fixed at any position in the part of the trough body 3c where the slit 27 is formed. In addition, the bolt receiving bracket 35 is movable in the longitudinal direction of the trough body 3c. For this reason, the position of the bolt receiving bracket 35 can be adjusted to match the position of the bolt hole 21a formed in the trough cover 5, and the trough cover 5 can be easily fixed to the trough body 3c even if the position of the bolt hole 21a is slightly off.
[0072] (Fifth Embodiment) Next, a fifth embodiment will be described. In the fifth embodiment, a method for forming a connected structure in which a plurality of drop-lid-shaped troughs are connected will be described. In the following description, an example using a trough body 3c and a trough cover 5 will be shown, but other trough bodies and trough covers may also be used.
[0073] Figure 12A shows the process of connecting a new trough body 3c (left side in the figure) to the previously installed trough body 3c (right side in the figure). As mentioned above, a male body connecting part 11 is formed at one end of the trough body 3c (right side in the figure), and a female body connecting part 13 is formed at the other end of the trough body 3c (left side in the figure).
[0074] Figure 13A is a plan view of the main body male connector 11 and the main body female connector 13. The main body male connector 11 is formed to be narrower than the width of the side wall of the trough body 3c, and a projection is formed at its end that protrudes outward. On the other hand, the main body female connector 13 has a projection at its end that protrudes inward.
[0075] As shown in Figure 12A, the male connecting portion 11 of the trough body 3c is inserted into the female connecting portion 13 of the trough body 3c from above, thereby connecting the trough bodies 3c together as shown in Figure 12B.
[0076] Figure 13B shows the state in which the main body male connector 11 and the main body female connector 13 are connected. The outer projection of the main body male connector 11 and the inner projection of the main body female connector 13 interlock, connecting the trough bodies 3c together. Since there is clearance between the connection parts of the main body male connector 11 and the main body female connector 13, the trough bodies 3c can be connected by bending them at a predetermined angle. In this way, by sequentially connecting the main body male connector 11 of the trough body 3c to the main body female connector 13 of the existing trough body 3c, the trough bodies 3c can be installed to a predetermined length and cables can be laid.
[0077] Next, as shown in Figure 14A, the trough cover 5 is installed above the trough body 3c. Note that in the following figures, the trough body 3c is shown as a partial cross-section. The trough cover 5 is installed sequentially from the side opposite to the trough body 3c (left side in the figure). As mentioned above, the trough cover 5 has an overlapping portion 15a below the cover at one end in the longitudinal direction (right side in the figure) and an overlapping portion 15b above the cover at the other end in the longitudinal direction. First, as shown in the figure, the trough cover 5 is placed on the left side of the trough body 3c with the overlapping portion 15a below the cover facing the male connecting portion 11 of the trough body 3c.
[0078] As mentioned above, a fixing bracket 25 (see Figure 1) is attached near the female connecting portion 13 of the trough body 3c. Bolt holes 21 are formed in the trough cover 5 at positions corresponding to the fixing bracket 25. As shown in Figure 14B, the trough cover 5 is placed on the trough body 3c (cover mounting portion 9a), and the bolts 23 are inserted into the bolt holes 21 from above the trough cover 5 and tightened into the fixing bracket 25 fixed to the trough body 3c, thereby fixing the trough cover 5 to the trough body 3c.
[0079] Figure 14C is a plan view of Figure 14B. When the trough cover 5 is installed on the trough body 3c, the overlapping portion 15a of the trough cover 5 is positioned on the male connecting portion 11 of the main body. That is, the overlapping portion 15a is positioned so as to protrude onto the female connecting portion 13 of the adjacent (right side in the figure) trough body 3c.
[0080] Next, as shown in Figure 15A, the trough cover 5 is placed on the adjacent (right side in the figure) trough body 3c. The trough cover 5 is fixed to the trough body 3c by bolts 23 by inserting bolts into bolt holes 21 formed near the female connecting portion 13 of the trough cover 5, as described above. Figure 15B shows the state in which the trough covers 5 are fixed to each trough body 3c, and Figure 15C is a plan view of Figure 15B.
[0081] Here, when the trough covers 5 are sequentially fixed, the overlapping portion 15b of the upper part of the trough cover 5 (right side in the diagram) that is installed later is positioned so that it overlaps the overlapping portion 15a of the lower part of the trough cover 5 (left side in the diagram) that is installed earlier. In other words, by bolting the right trough cover 5, the overlapping portion 15a of the lower part of the trough cover 5 (left side) is pressed down from above by the overlapping portion 15b of the upper part of the trough cover 5 (right side).
[0082] As described above, the trough cover 5 is fixed to the trough body 3c by bolts 23 near the female body connection portion 13 (left side in the figure) of the trough body 3c. On the other hand, the male body connection portion 11 side of the trough body 3c is pressed down from above by the adjacent trough cover 5 (right side in the figure). Therefore, even if the trough cover 5 is fixed by bolts 23 only at one end in the longitudinal direction, the trough cover 5 is fixed to the trough body 3c near both ends in the longitudinal direction, which can prevent unintended lifting of the cover.
[0083] According to the fifth embodiment, a trough track of a desired length can be formed by connecting a plurality of drop-lid-shaped troughs.
[0084] (Sixth Embodiment) Next, a sixth embodiment will be described. In the sixth embodiment, a drop-lid type trough is processed and used. The following describes the method of fixing the trough body and trough cover in the drop-lid type trough connection structure (processing method for drop-lid type trough). When connecting drop-lid type troughs in the manner described above to form a trough track of a predetermined length, it may be necessary to adjust the length in some parts. In such cases, as shown in Figure 16A, the trough body 3c of the fourth embodiment can be cut and used. Figure 16B shows the cut trough body 43 after cutting.
[0085] The trough body 43 has a female connecting portion 13. That is, when the trough body 3c is cut, the male connecting portion 11 side is removed. Also, when the trough body 3c is cut, the cutting position is set so that the rib 17 is included at the end of the trough body 43. That is, by cutting the trough body 43 so that the rib 17 is included, the female connecting portion 13 is positioned on one end and the rib 17 is positioned on the other end.
[0086] From this state, as shown in Figure 16C, the main body male connecting portion 11 is formed using the rib 17. For example, from the state shown in Figure 16B, a part of the bottom plate portion 7 and a part of the side wall portion 9 are cut off, and the rib 17 is processed and used as a projection formed outward on the main body male connecting portion 11. In this way, the main body female connecting portion 13 can be formed on one end of the cut trough body 43, and the main body male connecting portion 11 can be formed on the other end.
[0087] Next, as shown in Figure 17A, the trough cover 5 is cut to match the length of the trough body 43 to obtain the cut trough cover 45. In this case, the cut trough cover 45 is cut shorter than the trough body 43 by the length of the overlapping portion 15a below the cover. The trough cover 5 is cut off on the side of the overlapping portion 15a below the cover. That is, the cut trough cover 45 has an overlapping portion 15b above the cover at one end (left side in the figure). For this reason, as shown in Figure 17B, the cut trough cover 45 has bolt holes 21 on both sides in the width direction near one end.
[0088] Next, as shown in Figure 17C, bolt holes 21a are provided on both sides in the width direction near the other end (right side in the figure) of the cut trough cover 45 (positions corresponding to the slit 27 of the trough body 3c). In this way, the trough body 3c and the trough cover 5 can be cut to predetermined lengths to obtain the cut trough body 43 and the cut trough cover 45.
[0089] Next, the bolt receiving bracket 35 (see Figures 11A and 11B) is inserted into the slit 27 of the cutting trough body 43, and the bolt receiving bracket 35 is fixed to the cutting trough body. Figure 18A is a plan view showing the state in which the bolt receiving bracket 35 is attached to the cutting trough body 43. The cutting trough body 43 has a fixing bracket 25 attached to one end (left side in the figure), and the bolt receiving bracket 35 is attached to the slit 27 at the other end.
[0090] The male connecting portion 11 of the cut trough body 43 obtained in this way can be inserted from above into the female connecting portion 13 of the existing trough body 3c, as shown in Figure 18B, thereby connecting it to the trough body 3c. In other words, the connection can be made using the same procedure as connecting two trough bodies 3c together. The existing trough body may be the trough bodies 3a and 3b according to the first to third embodiments.
[0091] Figure 18C shows the trough body 3c and the cutting trough body 43 connected. After this, the trough bodies can be connected to a predetermined length by connecting the trough body 3c or the male connecting part 11 of another cutting trough body 43 to the female connecting part 13 of the cutting trough body 43.
[0092] Next, as shown in Figure 19A, the cutting trough cover 45 is placed above the cutting trough body 43. At this time, the bolt receiving bracket 35 is aligned with the bolt hole 21a (see Figure 17C) of the cutting trough cover 45. As mentioned above, since the bolt receiving bracket 35 is movable within the range of the slit 27, even if the position of the bolt hole 21a is slightly off, it can be easily adjusted.
[0093] In this state, as shown in Figures 19B and 19C, the cutting trough cover 45 is placed on the cutting trough body 43, and bolts 23 are inserted from above into the bolt holes 21 of the cutting trough cover 45 and tightened into the fixing bracket 25 (see Figure 18A). Also, bolts 23a are inserted from above into the bolt holes 21a of the cutting trough cover 45 and tightened into the bolt receiving bracket 35. In this way, the cutting trough cover 45 can be fixed to the cutting trough body 43.
[0094] Next, as shown in Figure 20A, the trough cover 5 is placed on the trough body 3c. The trough cover 5 can be fixed to the trough body 3c by bolts 23. Figure 20B shows the state in which the trough cover 5 is fixed to the trough body 3c, and Figure 20C is a plan view of Figure 20B.
[0095] As mentioned above, when adjacent trough covers 5 are placed side by side, the overlapping portion 15b of one trough cover 5 is positioned above the overlapping portion 15a of the other trough cover 5, so the overlapping portion 15a of the other trough cover 5 is pressed down from above by the overlapping portion 15b of the other trough cover 5. However, the cut trough cover 45 does not have an overlapping portion 15a, so there is no overlapping portion with the overlapping portion 15b of the other adjacent trough cover 5. For this reason, the cut side of the cut trough cover 45 is not pressed down by the other adjacent trough cover 5. However, the cut trough cover 45 is fixed to the cut trough body 43 by bolts 23a using bolt receiving brackets 35. For this reason, it is possible to suppress the lifting of the cut trough cover 45.
[0096] Furthermore, the overlapping portion 15b of adjacent trough covers 5 will protrude onto the cut side of the cut trough cover 45. For this reason, the cut length of the cut trough cover 45 is shortened by the length of the overlapping portion 15b of the adjacent trough covers 5, or the cut trough cover 45 is made the same length as the cut trough body 43, and the adjacent trough covers 5 are cut shorter by the length of the overlapping portion 15b. By adjusting the length of the trough covers in this way, interference between adjacent trough covers can be prevented.
[0097] Thus, this embodiment is a connecting structure for drop-lid troughs that includes a pair of drop-lid troughs, where one drop-lid trough 1 is cut and the other drop-lid trough 1 is not cut, and the two are connected to each other. One trough body 3c is cut to a predetermined length at the rib position so as to include a predetermined number of slits 27 from one end to the other, the cut rib is processed as a male connecting part 11, and a cut trough body 43 having a female connecting part 13 is formed at one end.
[0098] The other uncut trough body 3c has a female body connecting portion 13 on one end and a male body connecting portion 11 on the other end. The trough bodies 3c are connected to each other by connecting the rib portion, which has been processed as the male body connecting portion 11 of the cut trough body 43, to the female body connecting portion 13 of the other trough body 3c. One cut trough cover 45 is cut shorter than the length of the cut trough body 43 by the length of the overlapping portion 15b on the cover of the adjacent other trough cover 5. The cut trough cover 45 is placed on the cut trough body 43 such that the position of the end of the overlapping portion 15b on the cover of the cut trough cover 45 coincides with the position of the end of the female body connecting portion 13 of the cut trough body 43.
[0099] The other trough cover 5, which is not cut, is placed on the trough body 3c such that its overlapping portion 15b abuts against the cut end of the cut trough cover 45 and extends toward the cut trough cover 45. Each trough cover is bolted to a fixing bracket 25 fixed to the respective trough body, while the cut trough cover 45 is bolted to a bolt receiving bracket 35 fixed to the cut trough body 43.
[0100] According to the sixth embodiment, the trough body 3c is cut at the rib position so as to include a predetermined number of slits 27 from one end to the other, with the body female connecting portion 13 at one end. The trough cover 5 is cut to a predetermined length that matches the cut trough body 43 from the side of the cover overlap portion 15b, or it is cut to be shorter by the length of the cover overlap portion 15b from this predetermined length. In other words, a cut trough body 43 and a cut trough cover 45 cut to a predetermined length are used.
[0101] Furthermore, a bolt receiving bracket 35 is inserted into the slit 27 of the cutting trough body 43, and the bolt receiving bracket 35 is fixed to the cutting trough body 43. The cutting trough cover 45 is placed on the cutting trough body 43, and bolts are inserted from above into the bolt holes 21 formed near the overlapping portion 15b of the cutting trough cover 45 and the bolt holes 21a formed at predetermined positions corresponding to the slit 27. By tightening the bolts into the fixing bracket 25 and the bolt receiving bracket 35, the cutting trough cover 45 can be fixed to the cutting trough body 43.
[0102] In this way, the length of the drop-lid trough can be adjusted by cutting, and by connecting it with other drop-lid troughs, a trough track of the desired length can be formed. Furthermore, by using the bolt receiving bracket 35, the lifting of the cut trough cover 45 can be suppressed. Although this embodiment was described using the trough body 3c of the fourth embodiment as an example, if it is not necessary to fix the cut trough cover 45 to the cut trough body 43 with bolts 23a, the trough bodies 3a and 3b of the first to third embodiments may be cut to form the cut trough body. That is, the cut trough cover and the cut trough body may be fixed only by bolt fixing to the fixing bracket 25 without using the bolt receiving bracket 35.
[0103] Although embodiments of the present invention have been described above with reference to the attached drawings, the technical scope of the present invention is not limited to the embodiments described above. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these will naturally also fall within the technical scope of the present invention.
[0104] For example, the structure of the fixing bracket is not particularly limited, as long as the trough body 3 and the trough cover 5 can be fixed together using bolts or nuts, which are fixing members.
[0105] Figure 21A shows, as an example, a fixing structure between the trough body 3 and the trough cover 5 using the fixing bracket 25 in the embodiment described above. As described above, a nut 26 is fixed to the fixing bracket 25. The fixing bracket 25 is attached to the trough body 3 near the female connecting portion of the main body, and the trough cover 5 is placed on the trough body 3. In this state, the trough cover 5 is fixed to the trough body 3 by inserting a bolt 23 into the bolt hole 21 of the trough cover 5 and tightening the bolt 23 into the nut 26 of the fixing bracket 25.
[0106] Alternatively, a fixing bracket 25a as shown in Figure 21B may be used. In the fixing bracket 25a, a bolt 23b is fixed instead of a nut 26. The male threaded portion of the bolt 23b stands upright. When installing the trough cover 5 on the trough body 3 to which the fixing bracket 25a is attached, the end of the bolt 23b is inserted into the bolt hole 21 from below the trough cover 5, and the end of the bolt 23b protrudes onto the trough cover 5. In this state, the trough cover 5 can be fixed to the trough body 3 by tightening a nut 26a onto the bolt 23b above the trough cover 5.
[0107] Here, since the trough body 3 is buried in the ground 31, there is a risk that soil and sand may enter over the upper side wall 9C. For this reason, if the fixing bracket 25 is used, there is a risk that soil and sand may enter inside the nut 26 below the fixing bracket 25. If soil and sand enter inside the nut 26, it will be difficult to remove them from the nut 26. For this reason, it will be difficult to close the trough cover 5 and tighten the bolt 23 into the nut 26.
[0108] In contrast, with the fixing bracket 25a, even if soil enters between the trough cover 5 and the trough body 3, the tip of the bolt 23b protrudes above the trough cover 5, so it does not interfere with tightening the nut 26a. Therefore, there is no problem in installing the trough cover. Thus, the fixing bracket can be appropriately selected depending on the situation.
[0109] 1... Drop-in lid trough 3, 3a, 3b, 3c... Trough body 5, 5a... Trough lid 7... Bottom plate 9... Side wall 9a... Lid mounting section 9b... Lower side wall 9c... Upper side wall 9d... Extended side wall 11... Male connector for main body 13... Female connector for main body 15a... Overlapping section below lid 15b... Overlapping section above lid 17... Rib 19... Recess 21, 21a... Bolt holes 23, 23a, 23b... Bolts 25, 25a... Fixing brackets 26, 26a... Nuts 27... Slit 29... Protrusion on the back 31... Ground 33... Protrusion 34... Step 35... Bolt receiving bracket 37... Main body 39... Locking claw 41... Nut section 43... Cutting trough body 45... Cutting trough cover
Claims
1. A drop-lid type trough comprising: a trough body having a bottom plate portion and side wall portions erected on both sides of the bottom plate portion; and a trough cover placed on the upper part of the trough body, wherein the trough cover is fixed in a position sandwiched between the side wall portions on both sides, wherein the side wall portion comprises a cover mounting portion on which the trough cover is placed, an upper side wall portion erected above the cover mounting portion, and a lower side wall portion formed below the cover mounting portion, wherein when the trough cover is placed on the cover mounting portion, the trough cover is positioned between the upper side wall portions on both sides, a recess is formed on the outer surface of the lower side wall portion, and a slit is formed in the cover mounting portion at the location where the recess is formed, connecting the space above the cover mounting portion with the external space of the trough body.
2. The drop-lid trough according to claim 1, characterized in that projections are formed on the inner surface of the upper side wall portion, projecting toward opposing directions from both sides of the upper side wall portion, and when the trough cover is placed on the cover mounting portion, the trough cover abuts against and is sandwiched between the projections on both sides.
3. The drop-lid-shaped trough according to claim 2, characterized in that, in a cross section perpendicular to the longitudinal direction of the trough body, the width of the slit formed from the inner surface of the upper side wall toward the center of the trough body is greater than or equal to the protruding length of the projection from the inner surface of the upper side wall.
4. The drop-in lid trough according to claim 1, characterized in that a pair of back projections projecting downward are formed on the back surface of the trough cover, and when the trough cover is placed on the cover mounting portion, both back projections each abut against the inner surfaces of the opposing lower side walls.
5. The drop-lid trough according to claim 4, characterized in that, in a cross section perpendicular to the longitudinal direction of the trough body, when the trough cover is placed on the cover mounting portion, the distance between the slits on both sides in the width direction is less than or equal to the width of the trough cover.
6. The drop-lid type trough according to claim 5, characterized in that a plurality of slits are formed in the longitudinal direction of the trough body at a predetermined length.
7. A drop-lid-type trough according to claim 1, characterized in that it has a bolt receiving fitting, the bolt receiving fitting is fixed to the side wall at the position of the slit, and the trough cover is fixed to the bolt receiving fitting with bolts.
8. The drop-lid trough according to claim 7, wherein the bolt receiving fitting has a main body portion inserted into the slit, a nut portion formed on the upper part of the main body portion, and a locking claw formed on the lower end of the main body portion, the locking claw is locked to a stepped portion formed on the outer surface of the lower side wall portion, and the bolt is fixed to the nut portion.
9. The drop-lid trough according to claim 1, characterized in that an extended side wall portion is formed below the upper side wall portion, extending further downward than the lid mounting portion, and a space communicating with the slit is formed between the extended side wall portion and the lower side wall portion.
10. A method for processing a drop-lid-shaped trough according to claim 1, characterized in that the trough body and the trough lid are each cut to a predetermined length, the cut trough lid is placed on the trough body, and the trough lid is fixed to the trough body with a fixing member.
11. A connecting structure for a drop-lid-shaped trough according to claim 1, wherein the trough body has a female body connecting portion at one end and a male body connecting portion at the other end, the trough cover has an upper overlapping portion at one end and a lower overlapping portion at the other end, adjacent trough bodies are connected by their respective female body connecting portions and male body connecting portions, the trough cover is placed on one trough body and the other trough cover is placed on the other trough body, the upper overlapping portion of the other trough cover is placed on the lower overlapping portion of the trough cover, and the trough cover is fixed to the trough body by a fixing member using a fixing fitting attached near the female body connecting portion.
12. The trough body is cut to a predetermined length at the rib position of the lower side wall portion so as to include a predetermined number of slits from one end to the other end of the trough body, and the trough cover is cut to a predetermined length that matches the trough body from the overlapping portion side of the cover, or cut to a length shorter than the predetermined length by the length of the overlapping portion of the cover, and the trough body cut to either length and the cut trough cover are fixed together, characterized in that the connecting structure for a drop-lid-type trough according to 11.
13. The connecting structure for a drop-lid-shaped trough according to 12, characterized in that a bolt receiving fitting is inserted into the slit of the trough body, the bolt receiving fitting is fixed to the trough body, a bolt is inserted from above into a bolt hole formed at a predetermined position corresponding to the slit, and the bolt is tightened into the bolt receiving fitting.
14. A method for fixing a trough body and a trough cover in a connecting structure of drop-lid troughs when one drop-lid trough is cut and the other drop-lid trough is not cut, using the drop-lid trough described in claim 1, wherein one trough body has only a female body connecting portion at one end, is cut to a predetermined length at the rib position of the lower side wall portion so as to include a predetermined number of slits from one end to the other end, and the cut rib is processed as a male body connecting portion, the other trough body has a female body connecting portion at one end and a male body connecting portion at the other end, and the connection between the trough bodies is performed by connecting the rib portion processed as a male body connecting portion of one trough body to the female body connecting portion of the other uncut trough body. A method for fixing a trough body and a trough cover in a trough connection structure with a drop-lid-type cover, characterized in that one of the trough covers is cut shorter than the length of one of the trough bodies by the length of the overlapping portion on the cover of the other adjacent trough cover, and the end of one of the trough covers is placed on one of the trough bodies so as to coincide with the end of the female connecting portion of one of the trough bodies, and the other trough cover that is not cut is placed on the other trough body so as to extend toward the one of the trough covers so as to abut the cut end of one of the trough covers, and each of the trough covers is fixed by fixing members using fixing fittings fixed to each of the trough bodies.