Grating and manufacturing method therefor

Abstract

To provide a grating and a manufacturing method therefor which can prevent tilting and falling out of a main member even when a large force from a heavy vehicle is applied, and which can also reduce a burden of inventory management of component members such as a side abutment member.SOLUTION: In a metallic grating in which multiple band plate-like main members 1 are arranged in parallel with each other with a band width direction as a vertical direction and side abutment members 3 are fixed to both sides thereof, the side abutment member 3 is a bend-processed product of a side view reverse L-shaped member having, in a bend region 33 from a vertical part 31 to a horizontal part 32 including a part of the vertical part, an elongated hole 35 serving as a connection point with the main member, such that by fixing the side abutment member 3 to both sides of the main member 1, a lower part 16 on both sides of the main member abuts against the vertical part 31 while an upper part 17 protruding more than the lower part is inserted into a vertical part 31 side of the elongated hole 35, and an overhanging upper end portion 171 of the upper part 17 fills a horizontal part 32 side of the elongated hole 35 so that an upper end surface 171a thereof is flush with an upper surface 32a of the horizontal part 32.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a metal grating and a manufacturing method thereof, and more particularly to a so-called flanged grating that is an assembled type (also called an assembled type) and is placed on a U-shaped drain or the like, and a manufacturing method thereof. [Background technology]

[0002] Metal gratings, which provide good drainage and high mechanical strength, are often used for gutter covers that are placed on gutters and other structures to cover them. Some plate-shaped gratings use an electric pressure welding method, which welds the joints together. This method is sturdy and excellent at maintaining the grating's shape. However, it requires electric pressure welding equipment, which is expensive and burdensome. Furthermore, compared to carbon steel gratings, electric pressure welding is more difficult with stainless steel gratings. There are also built-in gratings, such as those disclosed in JP 2010-281057, that do not rely on electric pressure welding. However, when heavy vehicles or the like run over the grating, the bearing bars, which are the main components of these built-in gratings, can tilt and break. In view of this, the present inventors have proposed an invention to improve this situation (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-127352 Summary of the Invention [Problem to be solved by the invention]

[0004] However, although Patent Document 1 prevents the main members from tipping over when a heavy vehicle or the like runs over the grating in Figures 1 to 7, there is a risk that the main members will fall out downward due to the gravity of the heavy vehicle. In addition, the flanged grating shown in Figure 8 of Patent Document 1 has end bars, which serve as side support members for L-shaped members when viewed from the side, made of formed members such as equal-leg angle steel, which poses the problem of having to manage inventory of the side support members, which are separate members, apart from the main members and connecting members.

[0005] The present invention aims to solve the above problems by providing a grating and a manufacturing method thereof that can prevent the main members from tilting or falling off even when a large force is applied by a heavy vehicle, and that also reduces the burden of inventory management of components such as side supports. DISCLOSURE OF THE INVENTION [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the first aspect of the present invention is a metal grating having side support materials fixed to both sides of a plurality of band-shaped main members arranged parallel to each other with the band width direction vertically, wherein the side support materials are bent into inverted L-shaped members when viewed from the side, and a long, narrow hole is provided in the bending region from the vertical portion to the horizontal portion, including part of the vertical portion, as a connection point with the main members, and by fixing the side support materials to both sides of the main members, the lower portions of both sides of the main members abut the vertical portions, while the upper portions of both sides of the main members, which are formed to protrude beyond the lower portions, are inserted into the vertical portions of the long, narrow hole, and the protruding upper end portions of the upper portions are flush with the upper surface of the horizontal portion, filling the horizontal portion side of the long, narrow hole. A second aspect of the present invention is a grating according to the first aspect, characterized in that recesses are formed in the end faces of the upper lower half portions of both upper sides of the main member below the upper end portions, and weld buildups are provided in the recesses, with the main member and the side backing members being fixed and integrated by the weld buildups.A third aspect of the present invention is a grating according to the first or second aspect, characterized in that the main member, the connecting members, and the side backing members are cut products formed from flat plate material of the same material and the same thickness.A fourth aspect of the present invention is a grating according to the second aspect, characterized in that the engagement hole, which is U-shaped in front view and cut upward from the lower edge of the connecting member, has small wart-like protrusions formed on the side walls of the notch that open at the lower edge of the connecting member and reach the notch bottom wall, and that protrude into the engagement hole from the side wall surface. In a fifth aspect of the present invention, a plurality of band-shaped main members arranged parallel to one another with their width directions raised, a precursor to side support members fixed to both sides of the main members by providing elongated holes at the connection points on both sides of the main members, and a plurality of connecting members arranged in a grid pattern with the main members and having a U-shaped cutout in a front view from the lower edge of the narrow band member raised in the width direction in accordance with the arrangement pitch of the plurality of main members, are cut out and formed into plate pieces from a metal flat plate material of the same material and thickness, and then the precursor to side support members are bent into an inverted L-shaped member in a side view, and the vertical portion of the vertical portion is cut out and formed into a plate piece. The method for manufacturing a grating includes forming the side support members in which the elongated holes are arranged in the bending region, including a portion thereof, that extends to the horizontal portion, then forming the main members and the connecting members into a lattice shape, abutting the lower portions on both sides of the main members against the vertical portion, while inserting the upper portions on both sides of the main members that protrude beyond the lower portions into the vertical portion side of the elongated holes, and making the upper end faces of the protruding upper end portions of the upper portions flush with the upper surface of the horizontal portion, filling the horizontal portion side of the elongated holes, assembling multiple main members to the side support members, and then welding and fixing the side support members to both sides of the main members. The grating of the sixth aspect of the present invention is characterized in that, in the fifth aspect described above, recesses are provided in the end faces of the upper lower halves of the upper parts of both sides of the main member, below the upper end parts, and the upper parts of both sides of the main member are inserted into the slots, and the protruding upper end parts of the upper parts fill the horizontal side of the slots, and then weld buildup parts are formed in the recesses, and the side support materials are welded and fixed to both sides of the main member. [Effects of the Invention]

[0007] The grating of the present invention and its manufacturing method can not only prevent the main members from tipping over, but also completely prevent them from falling off, even when subjected to the large force of a heavy vehicle traveling on it.Furthermore, it is possible to manufacture each component, such as the main members and side members, using a single type of metal flat plate material, which has great advantages, such as making inventory storage and management much easier. [Brief explanation of the drawings]

[0008] [Figure 1]FIG. 1 is a partial perspective view of one form of the grating of the present invention being assembled into a grating. [Figure 2] FIG. 2 is a plan view of the completed grating of FIG. 1. [Figure 3] FIG. 3 is a left side view of FIG. 2. [Figure 4] FIG. 4 is a view taken along the line IV-IV in FIG. 2. [Figure 5] FIG. 10 is an explanatory perspective view of assembling the main member into the side support member. [Figure 6] 10 is an explanatory cross-sectional view showing the main member inserted into the elongated hole of the side support material and welded and fixed to the side support material. FIG. [Figure 7] FIG. 7 is an explanatory cross-sectional view showing the state immediately before the main member is inserted into the side support member of FIG. 6. [Figure 8] FIG. 7 is an explanatory cross-sectional view of a grating in comparison with FIG. 6. [Figure 9] FIG. 10 is an explanatory cross-sectional view of the state immediately before the connecting member is assembled to the main member. [Figure 10] 10 is an explanatory cross-sectional view of the main member of FIG. 9 to which a connecting member is attached. [Figure 11] This is a schematic plan view of the side support material, including the preliminary member, main member, connecting member, and end plate, cut out from a single flat plate. DETAILED DESCRIPTION OF THE INVENTION

[0009] The grating according to the present invention will be described in detail below. Figures 1 to 11 show one embodiment of the grating of the present invention. Figure 1 is a partial perspective view of the grating being assembled, Figure 2 is a plan view of the grating completed from Figure 1, Figure 3 is a left side view of Figure 2, Figure 4 is a view taken along line IV-IV in Figure 2, Figure 5 is a perspective view of the main members being assembled into the side backing members, Figure 6 is a cross-sectional view of the main members inserted and secured into the slotted holes in the side backing members, Figure 7 is a cross-sectional view of Figure 6 before the main members are inserted into the side backing members, Figure 8 is a comparative cross-sectional view of Figure 6, Figure 9 is a cross-sectional view of the main members before the connecting members are attached to them, Figure 10 is a cross-sectional view of the main members attached to the main members in Figure 9, and Figure 11 is a plan view of the preliminary members, main members, etc. being cut from a single flat plate. Each figure is simplified to emphasize the essential parts of the invention for ease of understanding.

[0010] (1) Grating Grating G is a metal plate-like body that is rectangular in plan view, with side support members 3 fixed to both sides of multiple strip-shaped main members 1 that are arranged in parallel with their widths raised up and down. This metal grating G is a so-called built-in type, with the horizontal portions 32 that serve as flanges of the side support members 3 that are L-shaped in side view placed on the gutter side wall 71 (Fig. 4). This grating G comprises main members 1 also known as bearing bars, connecting members 2 also known as cross bars, side support members 3 also known as end bars, and end plates 4 (Figs. 1 to 4).

[0011] The main members 1 are metal processed parts made of carbon steel, stainless steel, or the like, with a length that matches the width of the gutter 7 or the like so that they can straddle the gutter 7 or the like (Figs. 1 and 2). The main members 1 form the engagement portions 14 with the connecting members 2 and are arranged parallel to each other with the band width direction aligned vertically. A plurality of main members 1 are arranged at a predetermined pitch to ensure a gap ε for the slit between adjacent main members 1. Here, the "upper and lower," "above," and "lower" of the main members 1 or the like in this invention, with the band width direction aligned vertically, refer to the literal "upper and lower," "above," and "below" of the grating G in Fig. 4, which is installed in the gutter 7 or the like, as viewed from the perspective of the paper.

[0012] The main member 1 of this embodiment is a strip-shaped plate-like body with engaged portions 14 formed by cutting out recesses from the upper edge 1a side to the lower edge 1b as shown in Figure 2, so that the connecting members 2 can be fitted in and maintained in a grid shape. Since the grating G has two connecting members 2 arranged, two engaged portions 14 are provided on each main member 1. The side end portions 15 on both sides of each main member are provided with upper portions 17 that protrude beyond the lower portions 16 (Figure 7). The lower portions 16 on both sides of the main member abut against the vertical portions 31 of the side support members 3 when forming the grating G, which will be described in detail later. The upper portions 17 on both sides of the main member, which protrude beyond the lower portions 16, are inserted into the vertical hole portions 35V of the slots 3 in the side support members 3, and the upper portions 17, having the curved line of the bending region 33 and an upper end portion 171, are inserted into the horizontal hole portions 35H. The upper portions 37 of the side support members are inserted into the slots 35 in the side support members 3 so as to block the entire area of ​​the slots 35. The lower end surfaces 173 of the upper portions 17 are formed in a horizontal plane. As shown in Figure 6, the main member upper part 17 is inserted into the slot 35 side of the vertical part 31 of the side support member. Therefore, even if a heavy vehicle drives over the completed grating G, the main member upper part 17 is received by the horizontal plate thickness surface 352 of the lower side hole end of the vertical hole part 35V of the slot 35. Meanwhile, the tip surface 171d of the upper upper end part 171 of the main member 1 is formed in a vertical plane and abuts or is close to the horizontal plate thickness surface 351 of the hole end of the horizontal hole part 35H of the slot 35 (Figure 6). When the main member 1 is integrated with the side support member 3, the protruding upper end part 171 of the upper part 17 is flush with the upper surface 32a of the horizontal part 32 of the side support member, filling the horizontal part 32 side of the slot 35. In order to facilitate the integration of the main member 1 and the side support material 3 by welding, a recess 1721 is formed in the thickness surface of the outer tip of the upper portion 17 on both sides of the main member, which is the end face of the upper lower half portion 172 below the upper end portion 171 (Figures 6 and 7).

[0013] The connecting member 2 is a metal member having engagement holes 24 cut out in a U-shape in front view from the lower edge 2b of a narrow band plate member that is raised in the band width direction to match the arrangement pitch of the plurality of main members 1 (Figs. 1 and 9). The connecting members 2 are arranged in a grid pattern with each main member 1, thereby creating gaps ε for the slits. In this embodiment, the connecting member 2 is in the form of a narrow strip plate and has a plurality of engaging holes 24 that fit into the engaged portions 14, in accordance with the pitch of the main members 1. The engaging holes 24 are as shown in Figure 1, with the lower edge 2b open and cut out in the shape of a recessed groove by both side walls 242 and a bottom wall 241. The engaging holes 24 are assembled from above so as to face the engaged portions 14 of each of the main members 1, which are arranged upright in the strip width direction at a predetermined pitch (Figure 9), and the connecting member 2 and main members 1 form a lattice pattern as shown in Figure 2. In conventional products, a groove for the engaged portion 14 is drilled in the main member 1, but in this invention, a groove for the engaging hole 24 is also drilled in the connecting member 2. In addition, small protrusions 24 are provided, and a fitting method is adopted for the main member 1 and connecting member 2, which minimizes the clearance between them, ensuring strength close to that of an electric pressure welding method.

[0014] More specifically, the engagement hole 24, which is U-shaped in front view and cut out upward from the lower edge 2b of the connecting member 2, has a notch side wall 242 that opens at the lower edge of the connecting member 2 and extends to the notch bottom wall 241. The notch side wall 242 has small, wart-like protrusions 242a that protrude from the side wall surface toward the center of the engagement hole 24. When the connecting member 2 is fitted into the main member 1 as shown in Figure 9 to form a lattice shape as shown in Figure 10, the tips of the small protrusions 242a minimize the clearance with the main member 1 or slightly interfere with the small protrusions 242a and are pressed against the strip surface of the main member 1, thereby firmly integrating the main member 1 and the connecting member 2 without any rattle. The connecting member 2, assembled into the lattice shape with the main member 1, is then welded to the end plates 4 at both ends. Here, the width of the connecting member 2 is smaller than the width of the main member 1, and after the lattice shape is formed, the upper edge 2a of the connecting member is approximately flush with the upper edge 1a of the main member, and the lower edge 2b of the connecting member is positioned above the lower edge 1b of the main member (Figure 4).

[0015] The side support material 3 is a long metal member that abuts against both side ends of each of the multiple main members 1 and is integrated with them (Fig. 2). Using a bending machine or similar, a flat strip-shaped preliminary member 3A with a perforated portion 35A is bent into an L-shape to form a bent side support material that is an inverted L-shaped member when viewed from the side (Figs. 1 to 5). It is made into a side support material 3 for a flanged grating. Regarding the elongated holes 35 in the side support members 3, first, strips of plate material with elongated perforated portions 35A are cut out to match the pitch of the main member 1 at positions corresponding to the upper portions 17 on both sides of the main member 1 (FIG. 11). The pre-stage members 3A are then transformed into the bent products of the side support members 3, and the planar perforated portions 35A become three-dimensional elongated holes 35 that conform to the inverted L-shape in side view shown in FIG. 5. The elongated holes 35, which serve as the connection points with the main member 1, are provided in the bending region 33 that extends from the vertical portion 31 of the inverted L-shaped member of the side support member 3 in side view to the horizontal portion 32, including part of the vertical portion (FIG. 5). The elongated holes 35 also extend to part of the horizontal portion 32. Here, the "vertical portion 31" and "horizontal portion 32" of the "side-view inverted L-shaped member relating to the side support member 3" in this invention literally refer to the vertical portion in the up-down direction of the page and the horizontal portion in the left-right horizontal direction of the page, as seen in Figure 4 when the grating G is installed in the gutter 7. By fastening the side support members 3 to both sides of the main member 1, the lower portions 16 on both sides of the main member abut against the vertical portions 31, and the upper portions 17 on both sides of the main member are inserted into the vertical portion 31 side of the slot 35, and the upper end portion 171 projecting from the upper portion 17 has its upper end surface 171a flush with the upper surface 32a of the horizontal portion 32, filling the slot 35 from the vertical hole portion 35V to the horizontal hole portion 35H on the horizontal portion 32 side.

[0016] When the elongated holes 35 of the side backing material 3 and the upper parts 17 on both sides of the main member are fitted together, the lower part 16 of the main member 1 abuts against the plate surface of the vertical part 31 of the side backing material 3, and the two are integrated by welding at the recesses 1721 (Fig. 6). The upper lower half parts 172 on both sides of the main member are inserted into the vertical hole parts 35H of the elongated holes 35 and incorporated into the grating G, and a weld overlay wd is provided in the recesses 1721 on the plate thickness surface at the outer ends of the upper lower half parts 172 of the main member 1 incorporated into the side backing material 3. The main member 1 and the side backing material 3 are fixed together by the weld overlay wd. In place of the slots 35, elongated cutouts 36 as shown in Figure 5 are formed on the side end surfaces 3d of the side support material 3. The end plates 4 that match the arrangement pitch of the main members 1 are incorporated into the slots 36, and as shown in Figure 5, the slots 36 have a shape in which one of the elongated side walls 353 that form the slots 35 is absent. Reference numeral 361 corresponds to the plate thickness surface 351 at the upper side hole end of the slots 35. Reference numeral 362 corresponds to the plate thickness surface 352 at the lower side hole end of the slots 35.

[0017] The end plates 4 are a pair of metal strip-shaped members that, together with the pair of side support members 3, form a rectangular frame in plan view (Fig. 2). The end plates 4 are fixed to the protruding end faces 2d on both sides of the connecting member 2 that crosses the main member 1. The end plates 4 are also arranged parallel to the main member 1 at a predetermined pitch, with the strip width direction facing up and down. In this embodiment, the width of the end plate 4 is equal to that of the main member 1 (FIGS. 1 and 11). The end plate 4 has the same shape as the main member 1, except that it does not have the engaged portion 14. The end plate 4 has the same lower portion 46, upper portion 47, upper lower half portion 472, and recess 4721 as the main member 1. As with the main member 1, the end plate 4 also has a recess 4721 formed in the end surface of the thickness of the tip of the upper lower half portion 472 of the end plate 4, which is assembled to the side support member 3 (FIG. 3). A weld overlay wd (not shown), similar to that shown in FIG. 6, is formed in the recess, and the end plate 4 and the side support member 3 are fixed and integrated by the weld overlay. Incidentally, if the protruding end surface 2d of the connecting member 2 were extended to the outer surface of the end plate 4 and the engaged portion 14 provided on the main member 1 were provided on the end plate 4, the end plate 4 would be identical to the main member 1. Therefore, the end plate 4 can be substituted for the main member 1. In addition, in FIG. 1, the illustration of the plurality of main members 1 arranged between the right lower end plate 4 and the main member 1 shown on the right lowermost side is omitted.

[0018] In this embodiment, the main members 1, connecting members 2, end plates 4, and side members 3 that make up the grating are all members with the same plate thickness t. The main members 1, connecting members 2, end plates 4, and side members 3 are cut and formed from the same flat plate material P. They are cut (cut-out) from flat plate material P of the same material and with the same plate thickness t, and the side members 3 are further bent using a bending machine or the like. Thus, the grating G comprises a plurality of main members 1 arranged at a predetermined pitch as described above, connecting members 2 orthogonal to each main member 1 in a lattice pattern, a pair of side members 3 joined to the side end portions 15 of each main member 1, and end plates 4 provided on both sides of the main members 1 and forming a rectangular frame together with the pair of side members 3, forming a desired rectangular plate-like body in a planar view.

[0019] (2) Grating manufacturing method Next, one method for manufacturing a grating will be described. In this method, flat plate material P of the same material and thickness is used to produce the cut products of the main member 1, connecting member 2, pre-stage member 3A of the side support member 3, and end plate 4. Next, the side support member 3, which is a bent product of the pre-stage member 3A, is produced, and then these members 1, 2, 3, and 4 are assembled to produce a grating G as shown in Figures 1 to 11.

[0020] First, the main member 1, connecting member 2, and pre-stage member 3A of the side support member 3, as well as the end plate 4, mentioned in "(1) Grating," are cut out into pieces from flat plate material P made of the same material and thickness, such as carbon steel or high-tensile steel, using a laser processing machine (Figure 11). A plurality of main members 1 are arranged parallel to one another with their width directions raised, and engaging holes 24 are provided corresponding to the pitch of the main members 1. The main members 1 and the connecting members 2 are arranged in a grid pattern. The main members 1 and the connecting members 2 are cut out into plate shapes from a metal flat plate P of the same material and thickness. The upper edge 1a of the main member 1 is provided with a groove-shaped engaged portion 14 at a location facing the engaging portion 24. Upper portions 17 are provided on both sides of the main member, protruding beyond the lower portions 16. At the upper portions 17 on both sides, recesses 1721 are provided in the end faces of the upper lower half portions 172 below the upper end portions 171. End plates 4, which are main member 1 without the engaged portions 14, are also cut out with lower portions 46, upper portions 47, and recesses 4721, similar to the main member 1. For the side support members 3 having slots 35 at the connection points on both sides of the main member, a cutout is formed in the precursor member 3A of the side support member 3 having perforated portions 35A for the slots 35.

[0021] Next, the precursory member 3A is bent into an inverted L-shaped member in side view using a bending bender or the like. A side support member 3 is produced in which a slot 35 is arranged in a bending region 33 extending from a vertical portion 31 of the L-shaped member in side view to a horizontal portion 32 including a part of the vertical portion. The planar perforated portion 35A of the precursory member 3A is transformed into a three-dimensional slot 35 in the side support member as a result of the bending process. In this way, the main member 1, connecting member 2, side support member 3, and end plate 4 described in (1) Grating are manufactured.

[0022] Next, the main members 1 and the connecting members 2 are assembled in a grid pattern. Simultaneously, the lower portions 16 on both sides of the main members are brought into contact with the vertical portions 31 of the side support members, and the upper portions 17 on both sides of the main members, which protrude beyond the lower portions 16, are inserted into the vertical hole portions 35V of the elongated holes 35 on the vertical portion 31 side, and the upper end surfaces 171a of the protruding upper end portions 171 of the upper portions are made flush with the upper surfaces 32a of the horizontal portions 32, filling the elongated holes 35 on the horizontal portion 32 side. In this way, the assembly of the multiple main members 1 and the side support members is completed.

[0023] Thereafter, both sides of the main member 1 are welded to the side support material 3, and end plates 4 are fitted into the elongated notches 36 on both end faces 3d of the side support material 3, and the end plates and the side support material 3 are welded to each other. Specifically, the lower portions 16 on both sides of the main member 1 are abutted against the vertical portions 31 of the side plates, while the upper portions 17 are inserted into the slots 35 of the side plates 3. The protruding upper end portions 171 of the upper portions 17 then fill the horizontal hole portions 35H on the horizontal portion 32 side of the slots 35. Next, a welding machine is used to form weld buildups wd in the recesses 1721 visible on the outside of the vertical portions 31 (FIG. 6), and the side plates 3 are welded to both sides of the main member 1. Recesses 4721 similar to those on the main member 1 are also provided on both sides of the end plate 4 in FIG. 3. Weld buildups (not shown) are formed in these recesses, and the side plates 3 are welded to both sides of the end plate 4. The protruding end faces 2d of the connecting member 2 are welded to the end plate 4, integrating the connecting member 2 and the end plate 4. In this way, the desired grating G shown in Figures 2 to 4 is obtained.

[0024] (3) Effects In a grating configured in this way and its manufacturing method, the upper lower half portion 172 of the main member upper portion 17 is inserted and fixed into the vertical hole portion 35V of the elongated hole 35 in the side support member vertical portion 31. Therefore, even if a large gravity is applied to the grating G due to a heavy vehicle traveling, the side support member 3 receives and supports the main member upper portion 17 on the plate thickness surface 35 at the lower side hole end of the vertical hole portion 35V, so the main member 1 will not fall out downward due to the gravity of the heavy vehicle. This solves the problem in Patent Document 1, where the bearing bar may fall out of the grating G.

[0025] Furthermore, when small protrusions 242a are formed on the cutout side walls 242 associated with the engagement holes 24 of the connecting member 2 (Fig. 9), when the connecting member 2 is fitted into the main member 1 to form a grid, the small protrusions 242a minimize the clearance with the band plate surface of the main member 1 or are pressed against the band plate surface so as to be crushed (Fig. 10), so the main member 1 and connecting member 2 are integrated without rattle. Even if a large force is applied by sudden braking or sudden steering of a heavy vehicle traveling on the grating G, the main member 1 will not rattle or tilt.

[0026] A slot 35 is provided in the bending region 33 extending from the vertical portion 31 of the side support member 3 to the horizontal portion 32, including part of the vertical portion, and the lower portions 16 on both sides of the main member abut against the vertical portions 31 of the side support member, while the upper portion 17 is inserted into the vertical hole portion 35V on the vertical portion 31 side, and the upper end portion 171 is inserted into the horizontal hole portion 35H to fill the slot 35. Not only is the upper portion 17 of the main member 1 prevented from tilting by the vertical hole portion 35V of the side support member 3 into which it is inserted, but it is more reliably prevented from tilting by the horizontal hole portion 35H into which the upper end portion 171 of the upper portion of the main member 1 is inserted. In particular, horizontal holes 35H extending from vertical holes 35H are formed in the elongated holes 35 of the side support members 3, and a protruding upper end portion 171 of the upper portion 17 is formed at the main member side end portion 15, with the upper end portion 171 inserted into the horizontal hole portion H. Here, the greatest tilting force is applied to the upper edge portion of the main member 1 as a heavy vehicle travels, but this can be effectively prevented from tilting. In addition, the weld padding wd in the recess 1721 strengthens the main member 1 and the side support members 3 as a whole. The integration of the side support members 3 and the upright-mounted main member 1 is strong, and even when a heavy vehicle turns or drives over the built-in grating G and complex forces are applied to the grating G, the main member 1 will not tilt and will remain solid.

[0027] In addition, if the main member 1, connecting member 2, and pre-stage member 3A and end plate 4 of the side support member 3 are cut products formed from flat plate material P of the same material and thickness, the grating G can be manufactured by inventorying a single type of flat plate material P, which significantly reduces the labor and storage space required for procuring and inventorying each of the component members 1, 2, 3, and 4. There is also no need to prepare equal-leg angle irons or the like as L-shaped components when viewed from the side. The grating G can be manufactured by preparing only the flat plate material P alone. Inventory management of component members such as the main member 1 and side support members 3 becomes extremely easy.

[0028] Furthermore, unlike conventional equal-leg angle steel, the side support material 3 forms a bending region 33, so that rainwater W that falls on rainy weather and runs along the road surface and reaches the grating G flows smoothly over the bending region 33 as shown by the arrows in Figure 4, passes through the slit gap ε between the main members 1, and flows down into the gutter, resulting in a grating with good drainage properties. Furthermore, if a conventional bearing bar 9 made simply of a strip plate is applied to the main member 1, a gap S is formed between the side support member 3 and the side end face 91, which looks unattractive, as shown in Figure 8. In contrast, with the grating G of the present invention, the upper edge 1a of the main member and the upper face 32a of the horizontal part 32 of the side support member are flush with each other, as shown in Figures 2 and 6, so that it harmonizes with the bending region 33, and if installed in an entrance or the like, it exudes a sense of luxury and looks good, contributing to improving the scenery.

[0029] Furthermore, if all components 1 to 4 are made of flat plate material P of the same material and thickness, and high-tensile steel with high tensile strength is used for the flat plate material P, the plate thickness t can be reduced and the grating G can be made lighter because high-tensile steel is hard and strong. As described above, the present grating and its manufacturing method exhibit the many excellent effects described above and are extremely useful.

[0030] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention depending on the purpose and application. The shape, size, number, and material of the main member 1, connecting member 2, side support member 3, end plate 4, grating G, etc. can be selected appropriately depending on the application. In the embodiment, a laser processing machine was used to cut out and form the main member 1, etc. from the flat plate material P, but a plasma processing machine, water jet processing machine, etc. can be used instead. Furthermore, a bender bending machine was used to bend the side support member 3, which is the pre-stage member 3A, but this is not limited to this. The weld buildup portion wd also includes weld buildup portions that are not formed by TIG welding or the like, but only have welding marks. [Explanation of symbols]

[0031] 1 Main member 16 Lower 17 Upper 171 Upper end part 172 Upper lower half part 1721 depression 2 Connecting members 242 Notched sidewall 242a Depression 3 Side support material 31 Vertical section 32 Horizontal part 35 slotted hole G grating P flat plate material wd Weld overlay

Claims

1. A metal grating in which side support members are fixed to both sides of a plurality of strip-shaped main members arranged parallel to each other with the strip width direction vertically. The side support material is a bent product of an inverted L-shaped member when viewed from the side, and a long, narrow hole is provided in the bending region from the vertical portion to the horizontal portion, including part of the vertical portion, which serves as the connection point with the main member.By fixing the side support material to both sides of the main member, the lower parts of both sides of the main member abut the vertical portions, while the upper parts of both sides of the main member, which are formed to protrude more than the lower parts, are inserted into the vertical portions of the long, narrow hole, and the protruding upper end parts of the upper parts fill the horizontal portion side of the long, narrow hole so that their upper end surfaces are flush with the upper surface of the horizontal portion.

2. A grating as described in claim 1, wherein a recess is formed in the end face of the upper lower half portion below the upper end portion at the upper part of both sides of the main member, and a weld overlay portion is provided in the recess, and the main member and the side support member are fixed and integrated by the weld overlay portion.

3. 3. A grating as described in claim 1 or 2, wherein the main member, the connecting member, and the side support members are cut products formed from flat plate material of the same material and thickness.

4. A grating as described in claim 3, wherein the engagement hole, which is U-shaped when viewed from the front and cuts upward from the lower edge of the connecting member, has a side wall on which a small wart-like protrusion is formed that extends from the side wall surface into the engagement hole, the side wall opening at the lower edge of the connecting member and extending to the bottom wall of the notch.

5. a plurality of strip-shaped main members arranged parallel to one another with their width directions raised, a precursor to side support members fixed to both sides of the main members with elongated holes at the connection points on both sides of the main members, and a plurality of connecting members arranged in a grid pattern with the main members and each having a U-shaped cutout in a front view from the lower edge of a narrow strip member raised in the width direction and having a plurality of engagement holes cut out in a U-shape from the front to match the arrangement pitch of the plurality of main members, the connecting members being cut out in a plate shape from a metal flat plate of the same material and thickness; Next, the pre-stage member is bent into an inverted L-shaped member in a side view, and the side support member is formed such that the elongated hole is disposed in a bending region from a vertical portion of the pre-stage member to a horizontal portion including a part of the vertical portion; Next, the main members and the connecting members are formed into a lattice shape, the lower parts on both sides of the main members are abutted against the vertical parts, while the upper parts on both sides of the main members that protrude further than the lower parts are inserted into the vertical parts of the elongated holes, and the upper end faces of the protruding upper end parts of the upper parts are made flush with the upper surface of the horizontal parts, filling the horizontal parts of the elongated holes, and after assembling the multiple main members to the side support members, the side support members are welded and fixed to both sides of the main members.

6. A method for manufacturing a grating as described in claim 4, wherein a recess is formed in the end face of the upper lower half portion below the upper end portion at the upper part of both sides of the main member, the upper parts of both sides of the main member are inserted into the elongated hole, and the protruding upper end portions of the upper parts fill the horizontal part side of the elongated hole, and then a weld buildup is formed in the recess, and the side support materials are welded and fixed to both sides of the main member.

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