JP2007046267A - Grating cover and drainage structure of road - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constitution capable of strengthening swallowing of rainwater, and capable of reducing the dropping quantity of an object wheel, in a grating cover formed in a constitution having risk of causing the object wheel largely drop in an opening part forming clearance of a main bar wider than a width of the object wheel traveling on the clearance. <P>SOLUTION: This grating cover has a guide member 21 having a water introducing surface 21a inclined larger than a flowing water gradient of a flowing water surface. An interval between a side bar 24 positioned on the upstream side in the flowing direction and the most upstream crossbar 16a positioned on its just downstream side, is set larger than an ordinary pitch between the respective crossbars. An inclination of this water introducing surface 21a is set smaller than an inclination of a virtual tangent F on the upper end of the side bar 24 when a virtual circle E having the same diameter as the object wheel A is supported at two points on the upper end of the side bar 24 and the upper end of the most upstream crossbar 16a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a grating lid and a drainage structure of a road using the same.

For example, in a general road where a roadway and a sidewalk are separated via a walking road boundary block, an apron portion having a running water surface inclined downward in the transverse direction outside is usually provided on the side of the roadway. In such an apron section, water collecting basins having a grating lid are installed at predetermined intervals in the longitudinal direction, and each of the water collecting basins is U-shaped grooves or cross sections embedded in the longitudinal direction below the apron part. They are connected to each other by circular water collecting pipes.
On the surface of the flowing water in the apron part of the road, when the flowing water gradient becomes steep to some extent (generally 1% or more), a flow having a shallow water depth and a high flow velocity may be generated. When such a jet flow occurs, it may pass through the gap of the catching lid of the catchment basin, and rainwater may not be sufficiently swallowed, and the roadway side of the road may be flooded.

  In order to prevent the drainage performance from deteriorating due to the occurrence of the above-described jet flow, for example, as shown in Patent Document 1, a member having a water conveyance surface inclined more greatly than the water flow gradient of the water flow surface is used for A structure provided at the inlet portion (upstream side) has been proposed. Thereby, water can be actively dropped down by flowing water along the member which has a water conveyance surface.

Japanese Patent Laying-Open No. 2004-124690 (FIG. 1)

The grating lid described in Patent Document 1 is manufactured by casting, and prevents a front wheel of a wheelchair traveling on the grating lid from falling into a stepped portion between the grating lid surface and the water guide surface. In order to do so, a raised rib is provided to fill the height difference between the two.
In addition to such a grating lid, for example, a straight steel material such as a flat bar having an I cross section is used as a main bar. In this grating lid, the gap between the main bars is generally wider than the width of the front wheel of the wheelchair. Therefore, in order to reduce the amount of depression of the front wheel of the wheelchair in the grating lid, as shown in FIG. 8, the interval between the cross bars 48 provided in the direction orthogonal to the main bar 45 is reduced to, for example, 50 mm. . As a result, the wheel 49 is prevented from being greatly dropped (the amount of drop of the wheel 49). However, in this case, there is a problem that the rainwater passes through the gap of the grating lid particularly when the rainwater becomes the above-mentioned mixed flow, and the rainwater stagnation worsens in the grating lid.
Therefore, in this grating lid, it is conceivable to provide a member having a water conveyance surface inclined more greatly than the running water gradient of the running water surface at the inlet portion (upstream side) of the grating lid. However, since the cross bar crosses over the surface of the flowing water, the cross bar interferes with the rainwater flowing along the surface of the flowing water. Accordingly, it is conceivable to remove this cross bar, but this causes a problem that the cross bar pitch becomes wider and the amount of wheel dropping between the main bars increases (the amount of wheel 49 dropping).

  Therefore, the present invention provides a grating lid that is configured such that the target wheel may fall into the opening greatly due to the gap between adjacent main bars being wider than the width of the target wheel traveling on the main bar. An object of the present invention is to provide a configuration that can enhance the stagnation of rainwater and reduce the amount of dropping of the target wheel into the opening.

  To achieve the above object, the present invention comprises a plurality of main bars extending in the direction of water flow on the surface of the flowing water, and a plurality of cross bars extending in a direction crossing the flow direction so as to interconnect the main bars. Grating that is formed in a lattice shape, the longitudinal ends of the main bars are connected to each other by a side bar, and the gap between adjacent main bars is wider than the width of the target wheel that runs on the main bar. In the lid, a guide member having a water guide surface inclined more greatly than a running water gradient of the running water surface is extended from the side bar toward the main bars, and the side bar located on the upstream side in the flow direction and immediately there The interval between the most upstream crossbar located on the downstream side is set to be larger than the normal pitch between the crossbars, and The inclination angle is smaller than the inclination angle of the imaginary tangent line at the upper end of the sidebar when two virtual circles having the same diameter as the target wheel are supported on the upper end of the sidebar and the uppermost crossbar. It is set so that it becomes.

  According to this grating lid, since the guide member having the water guide surface inclined larger than the running water gradient of the running water surface from the side bar to the main bars is provided, it is possible to enhance the rainwater stagnation in the grating lid. . Furthermore, since the interval between the side bar located on the upstream side and the most upstream crossbar is set larger than the normal pitch, the most upstream crossbar interferes with the flowing water flowing on the flowing water surface. Can be prevented, and the swallowing performance can be improved. And even if this interval is wider than the normal pitch, the target wheel is supported at two points, not the upper end of the side bar, but the point on the water guide surface of the guide member and the upper end of the most upstream crossbar. The amount of depression of the target wheel can be reduced. That is, the target wheel can be supported by two points that are narrower than the distance between the side bar located on the upstream side and the most upstream crossbar, and the amount of drop of the target wheel can be reduced.

  In addition, it is preferable that a protrusion that protrudes to reduce the gap between the main bars is formed at a position between the side bar and the most upstream crossbar and above the main bar. . According to this, the two points that support the target wheel are on the projection part and the water guide surface of the guide member, the interval for supporting the target wheel can be further narrowed, and the amount of drop of the target wheel is further reduced Can be made.

  The flowing water surface is inclined straightly downward from the downstream end of the first gradient surface at a first gradient surface that is inclined downward straight from the side bar and at a larger inclination angle than the first gradient surface. And a second inclined surface. According to this, rainwater can be guided downward by the first slope surface. And in the 2nd slope surface, the rainwater guide | induced downward by the 1st slope surface can fall further below.

Moreover, it is preferable that the inclination angle of the first slope is set to 5 ° to 15 °.
According to this, since the inclination angle of the first slope surface is small, the amount of drop of the target wheel can be reduced, and further rainwater can be flowed stably, and the function of swallowing rainwater can be enhanced.

  Further, the target wheel traveling on the grating lid is a front wheel of a wheelchair. Thereby, although the front wheel of a wheelchair falls between main bars, the amount of depression can be made small by the guide member.

Further, the road drainage structure of the present invention includes a grating frame embedded in the road so that an upper edge surface is flush with the running water surface of the road, and an interior of the grating frame so as to be flush with the running water surface. And the grating lid fitted into the housing.
According to this configuration, since the guide member having the water guide surface is provided on the grating lid, the flowing water can be actively taken in even when the flowing water is in a diagonal flow state on the flowing water surface. And the amount of fall of the object wheel which runs on a grating lid and may fall between main bars can be made small.

  According to the present invention, the drainage performance can be enhanced by the guide member having the water guide surface. And the amount of depression of the wheel which falls to the opening part of a grating lid can be made small.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a drainage structure of a road where a lacing lid according to the present invention is used, and FIG. 2 is a perspective view showing the drainage structure.
The road shown in FIG. 1 has a running water gradient in which the road surface inclines downward toward the outer side in the transverse direction (the outer side in the left-right direction in FIG. 1), and the road surface is downstream in the longitudinal direction (the lower side in FIG. 1). It has a running water gradient that slopes downward toward In this road, longitudinal side grooves 10a and 10b in the longitudinal direction are provided on both the left and right sides, and a transverse groove 11 is provided in the transverse direction so as to connect the longitudinal side grooves 10a and 10b. And the grating lid 1 in which the rain water squeezing function is strengthened is fitted in the upper opening of the groove block 2 constituting the longitudinal grooves 10a and 10b and the transverse groove 11 in a continuous state in the longitudinal direction of the groove. . In addition, the arrow U of FIG. 1 and FIG. 2 is the upstream of the flow direction of the rainwater which flows through a road, and the arrow D has shown the downstream.

In FIG. 2, the groove block 2 includes a concrete block main body 13, a grating frame 14 embedded in the center of the block main body 13, and a grating lid 1 fitted inside the grating frame 14. ing.
The grating frame 14 is made of a frame material having an L-shaped cross section, and is fixed to each of the upper both edges of the groove of the block body 13 so that the upper edge surface thereof coincides with the running water surface 6 including the surface of the block body 13. ing. The grating lid 1 is made of a steel plate lattice member formed in a rectangular shape that substantially fits between both inner surfaces of the opposing grating frame 14, and the upper edge surface of the grating lid 1 coincides with the surface of the block body 13. 14 is fitted inside.

The grating lid 1 includes a plurality of main bars 15 arranged side by side in a direction perpendicular to the water flow direction on the flowing water surface 6, side bars 24 connecting the main bars 15 at their ends, and the side bars. 24 and a plurality of cross bars 16 that are parallel to the main bar 15 and connect the main bar 15 in the middle of the longitudinal direction. Has been. The main bar 15 is a flat steel having an I-shaped cross section, the cross bar 16 is a prismatic steel bar, and the side bar 24 is a flat steel.
The illustrated grating lid 1 has an assembly structure including a main bar 15, a side bar 24, and a cross bar 16, and is assembled by welding, press bonding, or the like. In addition, the structure of bar members, such as the grating lid | cover 1 and the main bar 15 which are shown in figure, is an example, Comprising: It does not limit to this embodiment.

  In the grating lid 1, the gap g between the adjacent main bars 15 is made wider than the width b of the target wheel A traveling on it. For example, there is a front wheel of a wheelchair as the target wheel A, and the width b of the front wheel is 25 mm, whereas the gap g of the main bar 15 of the grating lid 1 is 28 mm.

3 and 4 are sectional views of the grating lid 1. In these drawings, the end opening 18 between the side bar 24 on the upstream side in the flow direction and the most upstream crossbar 16a located immediately downstream thereof is the most upstream side opening in the grating lid 1, The end opening 18 is designed to enhance the penetration of rainwater flowing from the upstream flowing water surface 6.
Specifically, the most upstream cross bar 16a is provided far from the side bar 24, and the opening of the end opening 18 is enlarged so that rainwater can be easily swallowed from the upstream side. That is, the crossbar pitch p1 in the end opening 18 is set to be larger than the crossbar pitch (normal pitch) p2 in the other opening 19 downstream (p1> p2). For example, the crossbar pitch p1 of the end opening 18 is 100 mm, and the crossbar pitch p2 of the other opening 19 on the downstream side is 50 mm. Further, a guide member 21 having a water guide surface 21a inclined downward to allow rainwater to flow downward is provided at the end opening 18 so as not to obstruct the flow of rainwater on the water guide surface 21a. The most upstream cross bar 16 a is provided away from the side bar 24.

  Further, as shown in FIGS. 3 and 4, in the other opening 19 on the downstream side of the end opening 18, the crossbar pitch p <b> 2 is reduced, so that in the other opening 19. The amount of depression of the target wheel A is reduced. Specifically, when the crossbar pitch p2 of the other opening 19 is 50 mm and the diameter of the front wheel A of the wheelchair is φ130 mm, the sagging amount α is about 5 mm, which is safe.

And the guide member 21 which has the water conveyance surface 21a inclined more largely than the flowing water gradient of the flowing water surface 6 is extended from the side bar 24 in the said edge part opening part 18 of this grating lid | cover 1. FIG. Even if the flowing water becomes a jet by the guide member 21, the water can be dropped downward.
In FIG. 3, the water guide surface 21 a of the guide member 21 has a gradient surface (first gradient surface 22) having an inclination angle θ <b> 1 formed with the grating upper surface 17. As shown by a two-dot chain line in FIG. 3, the inclination angle of the inclined surface is the same as that of the target wheel A at the upper end of the side bar 24 and the upper end of the most upstream cross bar 16a located on the upstream side in the flow direction. The virtual circle E is set to be smaller than the inclination angle of the virtual tangent F of the virtual circle E at the upper end of the side bar 24 when the virtual circle E is supported at two points. Therefore, the target wheel A in the end opening 18 is lifted up by the guide member 21 as indicated by the solid line, and the amount of drop of the target wheel A is reduced.
That is, the guide member 21 has a function of strengthening the rainwater stagnation and a function of reducing the amount of depression of the target wheel A for safety.

  The case of a conventional grating lid will be described with reference to FIG. 8. In this case, the crossbar pitch (normal pitch) is reduced (50 mm) and the pitch is the same in all openings. Therefore, when the grating lid is provided with a member (not shown) having a water guide surface by a length (for example, about 100 mm) effective for enhancing the penetration of rainwater, the crossbar 48a on the most upstream side is provided with the water guide surface. The cross bar 48a has a problem that the rain water may be trapped. In order to solve this problem, a configuration in which the most upstream crossbar 48a is eliminated can be considered. However, in this case, the distance from the side bar 46 to the next cross bar 48b is 100 mm. Thereby, like the wheel 49 shown by the two-dot chain line in FIG. 8, the wheel 49 may fall greatly between the main bars 45 on the upstream side of the grating lid (the amount of drop of the wheel 49). However, according to the grating lid 1 of the present invention, the guide member 21 can lift the target wheel A upward in FIG. 3, and the amount of depression is reduced.

  The water guide surface 21 a of the guide member 21 shown in FIG. 3 is bent at an intermediate portion in the flow direction, and is continuously different from the first gradient surface 22 as the gradient surface and the downstream side of the first gradient surface 22. And a second gradient surface 23 having an inclination angle θ2. The first gradient surface 22 is a surface that is inclined downward straight from the upper end of the side bar 24, and the second gradient surface 23 has a larger inclination angle than the first gradient surface 22, and the first gradient surface 22 The surface is inclined downward straight from the downstream end of 22. Since the second gradient surface 23 has an inclination angle larger than that of the first gradient surface 22, the distance in the direction along the grating upper surface 17 of the water guide surface 21 a can be shortened, and the apparent aperture ratio Can be increased. Then, rainwater can be guided downward as close as possible from the sidebar 24. The inclination angle θ2 of the second gradient surface 23 is also set smaller than the inclination angle of the virtual tangent line F.

  As shown in FIG. 3, the first slope surface 22 has a contact point that receives the target wheel A from below. That is, the target wheel A can be supported on the first gradient surface 22 whose height position is higher than the second gradient surface 23 in the water guide surface 21a of the guide member 21, and the amount of depression of the target wheel A is reduced. Yes. The downstream end of the second gradient surface 23 is positioned lower than the most upstream crossbar 16a, and the opening area between the most upstream crossbar 16a and the second gradient surface 23 of the water guide surface 21a is increased.

The inclination angle θ1 of the first gradient surface 22 and the inclination angle θ2 of the second gradient surface 23 will be described. The inclination angle θ1 of the first slope surface 22 is preferably 30 ° or less, particularly preferably 15 ° or less, from the viewpoint of reducing the amount of depression of the target wheel A. If the angle is larger than this angle, the amount of depression of the target wheel A becomes too large, which is not preferable in terms of safety. On the other hand, from the viewpoint of the rainwater penetration function, the inclination angle θ1 is preferably 20 ° or less, and particularly preferably 15 ° or less. If the angle is larger than this angle, the rainwater does not flow from the upper end of the side bar 24 along the first slope surface 22 but tends to fly over the end opening 18 so that a stable water flow can be obtained. Therefore, it may be difficult to exert a desired squeezing function. Therefore, the particularly preferable inclination angle θ1 set from both viewpoints is set to 15 ° or less. Furthermore, the inclination angle θ1 is preferably 5 ° or more. If this inclination angle θ1 is too small, the effect of guiding rainwater downward may be reduced. In addition, the inclination angle θ2 of the second gradient surface 23 is preferably larger than the inclination angle θ1 and not more than 35 °.
Although not shown, the guide member 21 is not a two-stage structure having two inclined surfaces having different inclination angles as shown in the drawing, but may have a structure having a water guide surface 21a that is inclined straight by one inclination angle θ1. Good.

  Next, hydraulic test results for the function of squeezing running water are shown. As an example, the water guide surface 21a is inclined straight downward (Example 1), and the water guide surface 21a is a two-stage shape having a first slope surface 22 and a second slope surface 23 (Example 2). There is Example 3). In Example 2, the difference in inclination angle between the first gradient surface 22 and the second gradient surface 23 is 5 °, and in Example 3, the difference in inclination angle is 10 °. Moreover, as shown in the explanatory view of FIG. 5, the length L of the water guide surface 21a is 100 mm in both the first to third embodiments. The length of the water guide surface 21a is the horizontal distance when the grating lid 1 is placed on a horizontal plane. Furthermore, in each embodiment, the inclination angle of the water conveyance surface 21a is changed. And the distance V (FIG. 5) of each flowing water when the flowing water gradient is changed from 2% to 13.3% for Examples 1 to 3 is shown in the table below. The distance on the left side of each column in the table is the distance V between the intersection of the upper surface of the flowing water and the upper surface of the grating 17 and the upper end of the side plate 24. The smaller this value, the closer the water is to the side plate 24. It can be said that it has dropped down. And the right side of each column of the table shows the difference from the distance when there is no guide member 21 (comparative example), and it can be said that the larger this value is, the lower the water is dropped at a position closer to the side plate 24. . The unit of each value is mm. Each grating lid 1 is installed with an inclination at the same angle as the running water gradient.

  From the above results, Example 1 exhibits an effective squeezing function when the inclination angle θ1 of the water guide surface 21a of the guide member 21 is large. And in Example 2 and Example 3, considering that it is preferable that the inclination angle θ1 of the first gradient surface 22 is particularly 15 ° or less from the viewpoint of reducing the amount of depression of the target wheel A, the first The inclination angles (θ1, θ2) of the gradient surface 22 and the second gradient surface 23 are (10 °, 15 °), (15 °, 20 °), (10 °, 20 °), and (15 °, 25 In the case of (°), each flowing water gradient is hydraulically preferable. Therefore, it can be said from this test that the inclination angle θ1 of the first gradient surface 22 is preferably 10 ° to 15 ° and the inclination angle θ2 of the second gradient surface 23 is preferably 15 ° to 25 °. Particularly preferably, the inclination angle θ1 of the first gradient surface 22 is 15 °, the distance (L / 2) in the direction along the grating upper surface 17 of the first gradient surface 22 is 50 mm, and the inclination of the second gradient surface 23 is This is a case where the angle θ2 is 25 ° and the distance (L / 2) of the second gradient surface 23 is 50 mm.

  Next, the guide member 21 will be further described with reference to FIG. Side wall members 20 are provided on both sides in the width direction of the guide member 21, and the inner side surface of the side wall member 20 is perpendicular to the water guide surface 21 a of the guide member 21. The main bar 15 shown in FIG. 2 has an I-shaped cross section, but the inner side surface of the side wall member 20 is flush with the bulging upper side surface of the main bar 15. , A concave flow path is formed by the water guide surface 21 and the left and right inner surfaces. Thereby, both sides of the flowing water flowing on the water conveyance surface 21a are partitioned by the side wall member 20, and it is possible to suppress air from being taken into the bottom of the flowing water flowing on the water conveyance surface 21a. And it can prevent that flowing water leaves | separates (peels) from the water conveyance both surfaces 21a.

6 and 7 are sectional views showing another embodiment of the grating lid according to the present invention. Whereas the embodiment is made of steel, the grating lid 1 is made of cast iron. This grating lid 1 connects a plurality of main bars (vertical bars) 15 arranged side by side, a cross bar 16 intersecting with these main bars 15, and an end of the main bar 15, as in the above embodiment. The side bar 24 and the end opening 18 have the guide member 21. And like the said embodiment, this guide member 21 can support the wheel A at two points with the most upstream crossbar 16a. The difference is that these bar members are integrally formed. Further, in the end opening 18, a protruding portion 26 that protrudes so as to reduce the gap g of the main bar 18 is formed at a position above the main bar 15 and near the most upstream crossbar 16 a.
The protrusions 26 are provided so as to face each of the adjacent main bars 18, and the protrusion height h is set so that the gap g between the protrusions 26 is smaller than the width b of the target wheel A. (Fig. 7). Thereby, in the edge part opening part 18, the two points which support the object wheel A can be made into the guide member 21 and this projection part 26 (FIG. 6), and by narrowing the space | interval of the two points to support further, The amount of depression of the target wheel A can be further reduced.

As shown in FIG. 6, the shape of the protrusion 26 is linearly formed along the upper edge of the main bar 15 so as to go straight from the upper end side surface of the most upstream crossbar 16 a toward the guide member 21. It is a thing. Other than this, for example, although not shown, an independent protrusion formed in a protruding shape at the upper end of the side surface of the main bar 15 away from the most upstream crossbar 16a toward the guide member 21 at the end opening 18. It may be.
Even if such a protruding portion 26 is formed, the protruding portion 26 does not cross the rainwater flow section, and the position of the protruding portion 26 is closer to the most upstream crossbar 16a and the main bar 15 is located. Because it is the upper part of the water passage, the water flow cross section is not largely blocked. Therefore, the swallowing function is not lowered.

  As shown in FIG. 2, the road drainage structure of the present invention includes a grating frame 14 embedded in the road so that the upper edge surface is flush with the running water surface 6 of the road, and the running water surface 6. The grating lid 1 is fitted into the grating frame 14 so as to be flush with the other. The grating lid 1 is provided with the guide member 21, and even when the flowing water is in a diagonal flow state on the flowing water surface 6, the flowing water can be actively taken into the grating lid 1. Thereby, drainage performance can be improved. Furthermore, since the guide member 21 can support the target wheel A from below in the end opening 18 having an opening area wider than that of the other openings 19, the amount of drop of the target wheel A can be reduced.

  As described above, according to the grating lid 1 of the present invention, the width b of the target wheel A is narrower than the gap g of the main bar 15, and the diameter of the target wheel A is relatively small. This is particularly effective in the case of 1.2 to 2 times the crossbar pitch p1 of the end opening 18. In other words, the target wheel A can be a grating lid 1 that is highly safe with respect to the front wheel of a wheelchair, the wheel of a stroller, and the like.

It is a perspective view showing the drainage structure of the road where the grating lid concerning the present invention was used. It is a perspective view showing the drainage structure concerning the present invention. It is a figure which shows the cross section of the upstream part of 1st Embodiment of the grating lid which concerns on this invention. It is a figure which shows the cross section of the intermediate part of the grating lid | cover of FIG. It is explanatory drawing for demonstrating the grating lid | cover which performed the hydraulic test. It is a figure which shows the cross section of 2nd Embodiment of the grating lid which concerns on this invention. It is a figure which shows the cross section of the main bar of the grating lid | cover of FIG. It is sectional drawing explaining the conventional grating lid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Grating frame 6 Flowing water surface 14 Grating frame 15 Main bar 16 Cross bar 16a Top flow cross bar 17 Grating upper surface 18 End opening part 19 Other opening part 21 Guide member 21a Water guide surface 22 1st gradient surface 23 2nd gradient surface 24 Side bar 26 Protruding part A Target wheel b Target wheel width g Main bar gap p1, p2 Crossbar pitch E Virtual circle F Virtual tangent θ1 Inclination angle θ2 Inclination angle

Claims (6)

A plurality of main bars extending in the flow direction of water on the surface of the flowing water and a plurality of cross bars extending in a direction intersecting the flow direction so as to connect the main bars to each other are formed in a lattice shape. In the grating lid in which the longitudinal ends are connected by side bars, and the gap between the adjacent main bars is wider than the width of the target wheel that travels on the side,
A guide member having a water guide surface inclined more greatly than a water flow gradient of the water flow surface is extended from the side bar toward the main bars,
The distance between the side bar located upstream in the flow direction and the most upstream cross bar located immediately downstream thereof is set to be larger than the normal pitch between the cross bars, The inclination angle is smaller than the inclination angle of the virtual tangent line at the upper end of the sidebar when two virtual circles having the same diameter as the target wheel are supported on the upper end of the sidebar and the uppermost crossbar. A grating lid characterized by being set to be.   The protrusion part which protrudes so that the clearance gap between the said main bars may be made small in the position of the upper part of the said main bar between the said side bar and the said most cross bar is formed. Grating lid.   The flowing water surface has a first inclined surface inclined downward straight from the side bar, and a first inclined surface inclined downward straight from the downstream end of the first inclined surface at an inclination angle larger than the first inclined surface. The grating lid according to claim 1, comprising two inclined surfaces.   The grating lid according to claim 3, wherein an inclination angle of the first inclined surface is set to 5 ° to 15 °.   The grating lid according to any one of claims 1 to 4, wherein the target wheel is a front wheel of a wheelchair.   The grating frame embedded in the road so that the upper edge surface is flush with the running water surface of the road, and any one of claims 1 to 5 fitted into the grating frame so as to be flush with the running water surface A drainage structure for a road, comprising the grating lid according to claim 1.

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