Cover for underground structures

Abstract

To provide a lid for underground structure which suppresses rattling of a lid body which is generated due to a repeated load accompanying the travel of a vehicle and the like.SOLUTION: A lid body 5 of a lid 1 for underground structure includes a protrusion part 30 which protrudes from a lid body part 10 toward a first direction D11 of a first direction D1 which is in parallel with respect to a central axis C1 of an opening part 3 of a frame body 4. The protrusion part 30 includes a deformable part 60 which can elastically deform. The deformable part 60 includes: a first portion 80 which tapers toward the first direction D11; a second portion 90 which continues to the side of the first direction D11 with respect to the first portion 80, and in which the minimum thickness is the minimum thickness of the first portion 80; and a third portion 100 which continues to the side of the first direction D11 with respect to the second portion 90, and which tapers toward the first direction D11. The first portion 80 is in non-contact with respect to the frame body 4, and the second and third portions 90, 100 contain first and second contact parts 92, 102 coming into contact with respect to the frame body 4 respectively.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cover for an underground structure, which comprises a cover body that is supported so as to be openable and closable by a frame body that forms an opening connecting a road surface and an underground structure. [Background technology]

[0002] Patent Document 1 discloses a receiving frame for an underground structure lid that is configured so that the opening can be opened and closed using hinges attached to the lid body, in order to provide a receiving frame for an underground structure lid that allows for a wide opening space within the receiving frame and prevents rattling between the receiving frame and the lid body, and that is formed in an approximately rectangular shape having two short sides and two long sides, the planar shape of the short sides is formed in a curved shape, and the cross-sectional area of ​​the long sides is gradually increased from near the boundary of the short sides toward the center of the long sides. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 7-97817 A (Abstract) Summary of the Invention [Problem to be solved by the invention]

[0004] In covers for underground structures, it is necessary to suppress rattling of the cover body caused by repeated loads associated with the movement of vehicles and the like. [Means for solving the problem]

[0005] One aspect of the present invention is a lid for an underground structure, comprising a lid body supported by a frame body that forms an opening connecting a road surface and the underground structure and that can be opened and closed. The lid body includes a lid main body portion capable of closing the opening, a load transfer portion that transfers the load of the lid main body to the frame body, and a protrusion that protrudes from a first position on the lid main body portion in a first direction parallel to the central axis of the opening, from the road surface side toward the underground structure side. The protrusion includes a deformable portion that is elastically deformable to attenuate vibration of the lid body relative to the frame body. The deformable portion includes a first portion that tapers from a first thickness to a second thickness as it moves in the first direction, a second portion that is connected to the first portion on the side of the first direction and has a minimum thickness of the second thickness, and a third portion that is connected to the second portion on the side of the first direction and tapers from the second thickness to a third thickness as it moves in the first direction. The first portion is not in contact with the frame body. The second portion includes a first contact portion that contacts the frame body, and the third portion includes a second contact portion that contacts the frame body.

[0006] In this lid body for an underground structure, a protruding portion protruding from the lid main body in a first direction (typically downward) from the road surface toward the underground structure includes a deformable portion that is elastically deformable to attenuate vibration of the lid body relative to the frame body. The deformable portion includes first, second, and third portions in order toward the first direction. The first and third portions both taper toward the first direction, and a second portion is disposed between the first and third portions, the second portion having a minimum thickness equal to the minimum thickness of the first portion (second thickness). That is, the first and third portions, both tapering, are connected via the second portion, the thickness of which is equal to or greater than the minimum thickness of the first portion. This allows the rate of decrease in the thickness of the deformable portion to be reduced compared to the rate of increase in the distance from the position (first position) of the lid main body that is the starting point of the protruding portion toward the first direction. This makes it easy to increase the distance toward the first direction while maintaining the thickness of the deformable portion. Furthermore, in the cover body of this underground structure cover, the deformable portion can be elastically deformed by contacting the contact portions (first contact portion and second contact portion) of the second and third portions, which are farther from the starting point (first position) of the protrusion than the first portion, with the frame body. Therefore, when the deformable portion is elastically deformed, it is easy to reduce the external force (reaction force from the frame body) acting on the first and second contact portions, and as a result, it is easy to suppress deterioration of the deformable portion. Therefore, it is possible to provide a cover for an underground structure that is easy to suppress over a long period of time rattle of the cover body caused by repeated loads associated with the movement of vehicles, etc.

[0007] Preferably, the first portion includes a first inclined surface that inclines toward the central axis as it moves in the first direction, the second portion includes a first straight surface that extends along the first direction, and the third portion includes a second inclined surface that inclines toward the central axis as it moves in the first direction, the first straight surface including a first contact portion, and the second inclined surface including a second contact portion.

[0008] In this lid for an underground structure, the first and third portions, both tapered in the first direction, each include an inclined surface (first inclined surface) that approaches the central axis in the first direction. This prevents the deformable portion of the lid from interfering with the frame when opening and closing the lid relative to the frame. This reduces the likelihood of external forces acting on the deformable portion other than when the deformable portion is elastically deformed. Furthermore, because the first and second inclined surfaces are connected via a first straight surface extending along the first direction, when the deformable portion is elastically deformed, the first portion does not contact the frame, and the first contact portion of the second portion is likely to contact the frame. This allows the reaction force from the frame acting when the deformable portion is elastically deformed to be borne not only by the third portion, which tapers to less than the minimum thickness (second thickness) of the first portion (or the second thickness), but also by the second portion, which has a thickness equal to or greater than the minimum thickness (second thickness) of the first portion (or the second thickness). Therefore, deterioration of the deformable portion can be more easily suppressed.

[0009] Preferably, the first contact portion includes a bent portion connecting the first straight surface and the second inclined surface, and the second contact portion includes this bent portion. Because the bent portion between the first straight surface and the second inclined surface, which have different inclination angles relative to the first direction, can be brought into contact with the frame, it is easy to apply a reaction force from the frame to both the first and second contact portions continuously when the deformable portion is elastically deformed.

[0010] The inclination angle of the second inclined surface with respect to the first orientation is preferably smaller than the inclination angle of the first inclined surface with respect to the first orientation. By making the inclination angle of the second inclined surface, which is disposed closer to the first orientation than the first inclined surface, smaller than the inclination angle of the first inclined surface, the rate of reduction in the thickness of the deformable portion with respect to the first orientation can be further reduced.

[0011] This underground structure lid further includes a frame body that supports the lid body so that it can be opened and closed, and the frame body includes a deformation-inducing portion that can induce elastic deformation in the deformable portion, and the deformation-inducing portion preferably includes a non-contact surface that is not in contact with the deformable portion and a contact surface that is connected to the non-contact surface on the side facing in the first direction and that is in contact with the deformable portion. The first portion, which is closer to the starting point (first position) of the protrusion than the second and third portions, does not contact the frame body, and the contact portions of the second and third portions (first contact portion and second contact portion) can be reliably brought into contact with the frame body.

[0012] The inclination angle of the contact surface relative to the first direction is preferably smaller than the inclination angle of the non-contact surface relative to the first direction. By making the inclination angle of the non-contact surface larger than the inclination angle of the contact surface, the probability of contact between the first portion and the frame body can be further reduced.

[0013] The cover preferably includes a connecting portion connecting the load transmission portion and the protruding portion, the load transmission portion including a second straight surface extending in a second direction perpendicular to the first direction, the connecting portion including a recess recessed relative to the second straight surface toward the opposite side of the first direction, and the recess including a bottom surface formed at a first position. The bottom surface of the recess recessed relative to the second straight surface is formed at a first position on the cover body, which is the starting point of the protruding portion, allowing the protruding portion to protrude from the bottom surface of the recess. This reduces the external force (reaction force from the frame) acting on the first and second contact portions without increasing the size of the cover itself in the first direction. Therefore, a cover for an underground structure can be provided that is compact and can suppress deterioration of the deformable portion. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view of a cover for an underground structure according to one embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the underground structure cover shown in FIG. [Figure 3]FIG. 3 is a cross-sectional view of the main part of the underground structure cover in a state where the cover body is closed on the frame body. DETAILED DESCRIPTION OF THE INVENTION

[0015] Fig. 1 is a cross-sectional view of an underground structure lid 1 according to one embodiment of the present invention. Fig. 2 is an exploded perspective view of the underground structure lid 1. The underground structure lid 1 comprises a frame body 4 that forms an opening 3 connecting the road surface RS and the underground structure 2, a lid body 5 that is supported by the frame body 4 so that it can be opened and closed, a guide mechanism 6 that guides the movement of the lid body 5 so that the lid body 5 moves along a predetermined movement trajectory when the lid body 5 is opened and closed relative to the frame body 4, and a sealing material 7 that is disposed between the frame body 4 and the lid body 5 in a closed state where the lid body 5 is closed relative to the frame body 4 (hereinafter simply referred to as the "closed state"). Examples of underground structure covers 1 include manhole covers, large iron covers, and sewage manhole covers that close openings connecting underground buried objects or underground structure facilities in sewers to the ground, openable iron covers for common trenches that protect underground facility equipment or underground cables in electrical or communication equipment, iron covers for power transmission, iron covers for power distribution, fire hydrant covers that function as opening and closing doors connecting buried conduits under the road surface and their associated equipment in water supply or gas piping to the ground, water control valve covers, gate valve covers, air valve covers, gas piping covers, water meter covers, etc.

[0016] The frame 4 has an inner peripheral surface 4a that defines the opening 3 and has a substantially cylindrical shape. The opening 3 is formed by the inner peripheral surface 4a of the frame 4, and therefore has a substantially circular shape. In this example, the central axis C1 of the opening 3 extends along the vertical direction VD. The central axis C1 of the opening 3 is a direction that intersects with the road surface RS, typically a direction perpendicular to the road surface RS. The lid 5 includes a lid main body 10 that can close the opening 3, a load transfer part 20 that transfers the load of the lid main body 10 to the frame 4, multiple protrusions 30 that protrude from the lid main body 10, and a reinforcing part 40 that reinforces the lid main body 10. The lid main body 10 is substantially disc-shaped and has an upper surface 11 that is exposed to the road surface RS in the closed state, a lower surface 12 that faces the opening 3 in the closed state, and an outer peripheral surface 13 that connects the upper surface 11 and the lower surface 12. In this example, the central axis C2 of the lid main body 10 coincides with the central axis C1 of the opening 3 in the closed state. The load transfer portion 20 and the multiple protrusions 30 are formed integrally with the lid main body 10. The load transfer portion 20 is provided on the outer periphery of the underside 12 of the lid main body 10, and in this example, is provided continuously over the entire area (entire circumference) of the lid main body 10 in the circumferential direction CD. Each protrusion 30 is supported in a cantilevered manner by the lid main body 10. The multiple protrusions 30 are lined up along the circumferential direction CD of the lid main body 10. The reinforcing portion 40 includes a lattice-shaped rib provided on the underside 12 of the lid main body 10.

[0017] The guide mechanism 6 includes a guide member 45 provided on the frame 4, and a guided member 46 provided on the cover 5 and guided relative to the guide member 45. The guide member 45 has a guide hole 45a that guides the guided member 46. The guided member 46 includes a rod-shaped moving part 47 that is fixed to the cover 5 and moves relative to the guide member 45 while inserted in the guide hole 45a, and a retaining part 48 that prevents the moving part 47 from coming out of the guide hole 45a.

[0018] FIG. 3 is a cross-sectional view of a main portion of the underground structure cover 1 in a closed state. Below, each component will be described assuming the closed state unless otherwise specified. Each protrusion 30 protrudes from a first position P1 provided on the cover main body 10 in a first direction D1 (typically a vertical direction VD) parallel to the central axis C1 of the opening 3, in a first direction D11 (typically downward) from the road surface RS side toward the underground structure 2 side. The protrusion 30 includes an inner surface 31 located inside in a radial direction RD centered on the central axis C1, an outer surface 32 located outside in the radial direction RD, and a tip surface 33 connecting the inner surface 31 and the outer surface 32.

[0019] The inner surface 31 is a straight surface extending along a first direction D11. As will be described in detail later, the outer surface 32 has a portion that is inclined with respect to the first direction D11 so that an end of the outer surface 32 in the first direction D11 is closer to the inner surface 31 than an end of the outer surface 32 in a second direction D12 (typically upward) opposite to the first direction D11, and the inclination angle of the outer surface 32 with respect to the first direction D11 changes midway toward the first direction D11. The tip surface 33 is, for example, a curved surface whose central portion in the radial direction RD protrudes in the first direction D11.

[0020] The protrusion 30 includes a base portion 50 connected to the lid main body 10 at the first position P1, a deformable portion 60 connected to the base portion 50, and a tip portion 70 connected to the deformable portion 60. The deformable portion 60 elastically deforms by contacting the frame 4 so as to damp vibration of the lid body 5 relative to the lid main body 10.

[0021] The deformable section 60 includes a first portion 80 that tapers from a first thickness T1 to a second thickness T2 in a first direction D11; a second portion 90 that is contiguous with the first portion 80 on the side of the first direction D11 and has a second thickness T2 that is substantially constant in the first direction D11; and a third portion 100 that is contiguous with the second portion 90 on the side of the first direction D11 and tapers from the second thickness T2 to a third thickness T3 in the first direction D11. In this example, the first thickness T1 > the second thickness T2 > the third thickness T3. The maximum thickness of the first portion 80 is the first thickness T1, and the minimum thickness of the first portion 80 is the second thickness T2. The maximum and minimum thicknesses of the second portion 90 are the second thickness T2. The maximum thickness of the third portion 100 is the second thickness T2, and the minimum thickness of the third portion 100 is the third thickness T3. In addition, the first portion 80 is continuous with the root portion 50, and the third portion 100 is continuous with the tip portion 70.

[0022] The first portion 80 includes a first inclined surface 81 that inclines toward the central axis C1 of the opening 3 as it extends in the first direction D11. The second portion 90 includes a first straight surface 91 that extends along the first direction D11. The third portion 100 includes a second inclined surface 101 that inclines toward the central axis C1 of the opening 3 as it extends in the first direction D11. The first inclined surface 81, the first straight surface 91, and the second inclined surface 101 form part of the outer surface 32 of the protrusion 30. The inclination angle θ2 of the second inclined surface 101 with respect to the first direction D11 is smaller than the inclination angle θ1 of the first inclined surface 81 with respect to the first direction D11.

[0023] The first portion 80 is not in contact with the frame body 4. The first straight surface 91 of the second portion 90 includes a first contact portion 92 that contacts the frame body 4. The second inclined surface 101 of the third portion 100 includes a second contact portion 102 that contacts the frame body 4. The first contact portion 92 and the second contact portion 102 include a bent portion 110 that connects the first straight surface 91 and the second inclined surface 101.

[0024] In the closed state, the deformable portion 60 is elastically deformed due to the first contact portion 92 and the second contact portion 102 contacting the frame body 4. Therefore, strictly speaking, the first straight surface 91 may include a slightly deformed or inclined portion. However, even in such a case, the first straight surface 91 extends substantially parallel to the central axis C1 of the opening 3. Therefore, the inclination angle of the first straight surface 91 with respect to the first direction D11 is much smaller than the inclination angle θ2 of the second inclined surface 101. When the lid body 5 is opened relative to the frame body 4, i.e., before the first contact portion 92 and the second contact portion 102 contact the frame body 4, and the central axis C1 of the opening 3 and the central axis C2 of the lid main body 10 are aligned, the first straight surface 91 extends in the first direction D11 parallel to the central axis C1 of the opening 3.

[0025] In this example, the first contact portion 92 is only the bent portion 110, and the second contact portion 102 includes the bent portion 110 and a portion of the second inclined surface 101 that is closer to the first direction D11 than the bent portion 110, but is not limited to this. For example, the first contact portion 92 may include the bent portion 110 and a portion of the first straight surface 91 that is closer to the second direction D12 than the bent portion 110, and the second contact portion 102 may include only the bent portion 110. Alternatively, the first contact portion 92 may include the bent portion 110 and a portion of the first straight surface 91 that is closer to the second direction D12 than the bent portion 110, and the second contact portion 102 may include the bent portion 110 and a portion of the second inclined surface 101 that is closer to the first direction D11 than the bent portion 110.

[0026] The load transfer portion 20 includes a second straight surface 21 extending in a second direction D2 (typically, a horizontal direction) perpendicular to the first direction D1. The second straight surface 21 has, for example, an annular shape centered on the central axis C2 of the lid main body 10. The lid 5 further includes a connecting portion 120 connecting the load transfer portion 20 and the multiple protrusions 30. The connecting portion 120 includes a recess 121 recessed in a second direction D12 with respect to the second straight surface 21. The recess 121 has an annular shape centered on the central axis C2 of the lid main body 10. The recess 121 includes a bottom surface 122 formed at a first position P1 and a pair of wall surfaces (a first wall surface 123 and a second wall surface 124) rising from the bottom surface 122 toward the first direction D11. The first wall surface 123 is continuous with the second straight surface 21 , and the second wall surface 124 is continuous with the outer surface 32 of the protrusion 30 .

[0027] The frame 4 includes a deformation inducible portion 130 capable of inducing elastic deformation in the deformable portion 60 of the protrusion 30, a load support portion 140 that supports the load transmitted from the load transmission portion 20, and a main body accommodating portion 150 that accommodates the lid main body 10. The deformation inducible portion 130 includes a non-contact surface 131 that is not in contact with the protrusion 30, and a contact surface 132 that is connected to the non-contact surface 131 on the side of the first direction D11 and that is in contact with the deformable portion 60. The inclination angle θ4 of the contact surface 132 with respect to the first direction D11 is smaller than the inclination angle θ3 of the non-contact surface 131 with respect to the first direction D11. The contact surface 132 is in contact with a first contact portion 92 of a second portion 90 of the deformable portion 60 and a second contact portion 102 of a third portion 100 of the deformable portion 60. The load support portion 140 extends in the second direction D2 and includes a load support surface 141 that contacts the second straight surface 21 of the load transfer portion 20. The load support surface 141 has an annular shape centered on the central axis C1 of the opening 3. The load support surface 141 is continuous with the non-contact surface 131 of the deformation inducible portion 130. The main body accommodating portion 150 includes an opposing surface 151 that faces the outer peripheral surface 13 of the lid main body portion 10. The contact surface 132, the non-contact surface 131, the load support surface 141, and the opposing surface 151 form part of the inner peripheral surface 4a of the frame 4.

[0028] In this example, the inclination angle θ1 of the first inclined surface 81 is designed to be smaller than the inclination angle θ3 of the non-contact surface 131, and the inclination angle θ2 of the second inclined surface 101 is designed to be at least smaller than the inclination angle θ4 of the contact surface 132. The inclination angle θ2 of the second inclined surface 101 and the inclination angle θ4 of the contact surface 132 may be the same.

[0029] The sealing material 7 is, for example, an elastic member such as an O-ring. The sealing material 7 includes a first sealing portion 152 housed in the recess 121 and a second sealing portion 153 protruding from the recess 121. The second sealing portion 153 is located in a space 133 between the base portions 50 of the multiple protrusions 30 and the non-contact surface 131 of the deformation inducible portion 130. The sealing material 7 contacts the non-contact surface 131 and the pair of wall surfaces 123, 124. This prevents liquids such as rainwater and oil flowing in from the road surface RS from penetrating through the gap between the frame body 4 and the lid body 5 and toward the underground structure 2 relative to the load transmission portion 20.

[0030] According to this underground structure lid 1, the deformable portion 60 of the protruding portion 30 protruding from the lid main body 10 includes a first portion 80, a second portion 90, and a third portion 100, arranged in this order in the first direction D11. Between the first portion 80 and the third portion 100, which both taper toward the first direction D11, a second portion having a minimum thickness equal to the minimum thickness of the first portion 80 (second thickness T2) is disposed. That is, the first portion 80 and the third portion 100, which both taper toward the first direction D11, are connected via the second portion 90, which has a thickness equal to or greater than the minimum thickness of the first portion 80. Therefore, the rate at which the thickness of the deformable portion 60 decreases can be reduced compared to the rate at which the distance from the position (first position P1) of the lid main body 10, which is the starting point of the protruding portion 30, in the first direction D11 increases. Therefore, the distance in the first direction D11 can be increased while maintaining the thickness of the deformable portion 60. Furthermore, in the cover body 5 of this underground structure cover 1, the deformable portion 60 can be elastically deformed by contacting the contact portions (first contact portion 92 and second contact portion 102) of the second portion 90 and the third portion 100, which are farther from the starting point (first position P1) of the protrusion 30 than the first portion 80, with the frame body 4. Therefore, when the deformable portion 60 is elastically deformed, the external force acting on the first contact portion 92 and the second contact portion 102 (the reaction force from the contact surface 132 of the frame body 4) can be reduced, and as a result, deterioration of the deformable portion 60 can also be suppressed. Therefore, it is possible to provide an underground structure cover 1 that can suppress rattle of the cover body 5 caused by repeated loads associated with the travel of vehicles, etc., for a long period of time.

[0031] Furthermore, in the cover body 5 of this underground structure cover 1, the first portion 80 and the third portion 100, which both taper toward the first direction D11, each include an inclined surface (first inclined surface 81 and second inclined surface 101) that inclines toward the central axis C1 toward the first direction D11. This prevents the deformable portion 60 of the cover body 5 from interfering with the frame body 4 when opening and closing the cover body 5 relative to the frame body 4. This reduces the likelihood that an external force will act on the deformable portion 60 other than when the deformable portion 60 is elastically deformed. Furthermore, because the first inclined surface 81 and the second inclined surface 101 are connected via a first straight surface 91 that extends along the first direction D11, when the deformable portion 60 is elastically deformed, the first portion 80 does not contact the frame body 4, and the first contact portion 92 of the second portion 90 can contact the frame body 4. Therefore, the reaction force from the contact surface 132 of the frame 4 that acts when the deformable portion 60 is elastically deformed can be borne not only by the third portion 100 that tapers to less than the minimum thickness (second thickness T2) of the first portion 80, but also by the second portion 90 that ensures the minimum thickness (second thickness T2) of the first portion 80. This makes it possible to further suppress deterioration of the deformable portion 60.

[0032] According to this underground structure cover 1, the first contact portion 92 includes a bent portion 110 connecting the first straight surface 91 and the second inclined surface 101, and the second contact portion 102 includes this bent portion 110. Therefore, the bent portion 110 connecting the first straight surface 91 and the second inclined surface 101, which have different inclination angles θ1 and θ2 with respect to the first direction D11, can be brought into contact with the frame body 4. Therefore, when the deformable portion 60 is elastically deformed, a reaction force from the contact surface 132 of the frame body 4 can be applied continuously to both the first contact portion 92 and the second contact portion 102.

[0033] Furthermore, according to this underground structure cover 1, the inclination angle θ2 of the second inclined surface 101, which is disposed closer to the first direction D11 than the first inclined surface 81, is smaller than the inclination angle θ1 of the first inclined surface 81. Therefore, the rate of reduction in the thickness of the deformable portion 60 toward the first direction D11 can be further reduced.

[0034] Furthermore, according to this underground structure lid 1, the frame body 4 includes a deformation-inducible portion 130 that can induce elastic deformation in the deformable portion 60, and the deformation-inducible portion 130 includes a non-contact surface 131 that is not in contact with the deformable portion 60, and a contact surface 132 that is connected to the non-contact surface 131 on the side of the first direction D11 and that is in contact with the deformable portion 60. Therefore, the first portion 80, which is closer to the starting point (first position P1) of the protrusion 30 than the second portion 90 and the third portion 100, does not contact the frame body 4, and the contact portions of the second portion 90 and the third portion 100 (the first contact portion 92 and the second contact portion 102) can be reliably contacted with the contact surface 132 of the frame body 4. Furthermore, since the inclination angle θ2 of the second inclined surface 101 is designed to be the same as or smaller than the inclination angle θ4 of the contact surface 132, it is easy to increase the contact area (expand the contact region) between the second contact portion 102 and the contact surface 132. Therefore, it is easy to disperse the external force acting on the second contact portion 102 (the reaction force from the contact surface 132 of the frame body 4), and it is also easy to suppress deterioration of the deformable portion 60.

[0035] Furthermore, according to this underground structure cover 1, the inclination angle θ3 of the non-contact surface 131 is larger than the inclination angle θ4 of the contact surface 132. This further reduces the probability of contact between the first portion 80 and the non-contact surface 131 of the frame body 4. Furthermore, since the inclination angle θ1 of the first inclined surface 81 is designed to be smaller than the inclination angle θ3 of the non-contact surface 131, contact between the first portion 80 and the non-contact surface 131 of the frame body 4 can be reliably prevented.

[0036] Furthermore, according to this underground structure lid 1, the bottom surface 122 of the recess 121 recessed relative to the second straight surface 21 is formed at the first position P1 of the lid main body 10, which is the starting point of the protrusion 30, so that the protrusion 30 can protrude from the bottom surface 122 of the recess 121. This makes it possible to reduce the external force acting on the first contact portion 92 and the second contact portion 102 (the reaction force from the contact surface 132 of the frame body 4) without increasing the size of the lid body 5 itself in the first direction D1. Therefore, it is possible to provide an underground structure lid 1 that can suppress deterioration of the deformable portion 60 using a compact lid body 5.

[0037] The present invention is not limited to the above-described embodiment, and includes the following embodiments defined in the claims. For example, unlike the above-described embodiment, the second portion 90 of the deformable portion 60 may have a portion whose thickness is greater than the minimum thickness (second thickness T2) of the first portion 80, as long as the second portion 90 has the same minimum thickness (second thickness T2) as the first portion 80. Furthermore, the protrusion 30 does not necessarily have to be provided in multiple portions, and a single protrusion protruding from the lid main body 10 in the first direction D11 may be provided.

[0038] In addition, in the above embodiment, expressions such as "horizontal," "parallel," "vertical," "disk-shaped," "annular," "cylindrical," and "flat" are used, but these states are not required to be exact. In other words, these expressions allow for deviations in manufacturing precision, installation precision, and the like. [Explanation of symbols]

[0039] 1 Lid for underground structure, 2 Underground structure, 3 Opening, 4 Frame, 5 Lid, 10 Lid main body, 20 Load transfer portion, 21 Second straight surface, 30 Protruding portion, 80 First portion, 81 First inclined surface, 90 Second portion, 91 First straight surface, 92 First contact portion, 100 Third portion, 101 Second inclined surface, 102 Second contact portion, 110 Bent portion, 120 Connection portion, 121 Recess, 122 Bottom surface, 130 Deformation inducible portion, 131 Non-contact surface, 132 Contact surface, C1 Central axis, D1 First direction, D11 First orientation, D12 Second orientation (opposite side of first orientation) P1 First position, RS Road surface, T1 First thickness, T2 Second thickness, T3 Third thickness, θ1 Inclination angle, θ2 Tilt angle, θ3 Tilt angle, θ4 Tilt angle

Claims

1. A cover for an underground structure, comprising a cover body supported so as to be openable and closable by a frame body that forms an opening connecting a road surface and an underground structure, The lid body includes a lid main body portion that can close the opening, a load transmission portion that transmits the load of the lid main body portion to the frame body; a protrusion protruding from a first position of the lid main body in a first direction parallel to the central axis of the opening from the road surface side toward the underground structure side, the protrusion includes a deformable portion that is elastically deformable so as to damp vibration of the lid body relative to the frame body, The deformable portion includes a first portion that tapers from a first thickness to a second thickness in the first direction; a second portion that is contiguous with the first portion on the side facing the first direction and has a minimum thickness equal to the second thickness; a third portion that is continuous with the second portion on the side of the first direction and tapers from the second thickness to a third thickness as it moves in the first direction; the first portion is not in contact with the frame body, the second portion includes a first contact portion that contacts the frame body, the third portion includes a second contact portion that contacts the frame body, The frame body further supports the lid body so that the lid body can be opened and closed, the frame body includes a deformation inducible portion that can induce elastic deformation in the deformable portion, The deformation inducible portion has a non-contact surface that is not in contact with the deformable portion; A cover for an underground structure, comprising a contact surface that is continuous with the non-contact surface on the first direction side and that contacts the deformable portion.

2. The cover for an underground structure according to claim 1 , wherein the inclination angle of the contact surface relative to the first direction is smaller than the inclination angle of the non-contact surface relative to the first direction.

3. the lid body includes a connection portion that connects the load transmission portion and the protrusion, the load transmission portion includes a second straight surface extending in a second direction perpendicular to the first direction; the connection portion includes a recess recessed in a direction opposite to the first orientation with respect to the second straight surface, The cover for an underground structure according to claim 1 or 2, wherein the recess includes a bottom surface formed at the first position.

4. A cover for an underground structure, comprising a cover body supported so as to be openable and closable by a frame body that forms an opening connecting the road surface and the underground structure, The lid body includes a lid main body portion that can close the opening, a load transmission portion that transmits the load of the lid main body portion to the frame body; a protrusion protruding from a first position of the lid main body in a first direction parallel to the central axis of the opening from the road surface side toward the underground structure side, the protrusion includes a deformable portion that is elastically deformable so as to damp vibration of the lid body relative to the frame body, The deformable portion includes a first portion that tapers from a first thickness to a second thickness in the first direction; a second portion that is contiguous with the first portion on the side facing the first direction and has a minimum thickness equal to the second thickness; a third portion that is continuous with the second portion on the side of the first direction and tapers from the second thickness to a third thickness as it moves in the first direction; the first portion is not in contact with the frame body, the second portion includes a first contact portion that contacts the frame body, the third portion includes a second contact portion that contacts the frame body, the lid body includes a connection portion that connects the load transmission portion and the protrusion, the load transmission portion includes a second straight surface extending in a second direction perpendicular to the first direction; the connection portion includes a recess recessed in a direction opposite to the first orientation with respect to the second straight surface, A cover for an underground structure, wherein the recess includes a bottom surface formed at the first position.

5. the first portion includes a first inclined surface that is inclined so as to approach the central axis as it moves in the first direction; the second portion includes a first straight surface extending along the first direction; the third portion includes a second inclined surface that is inclined toward the central axis as it moves in the first direction, the first straight surface includes the first contact portion; A cover for an underground structure as described in any one of claims 1 to 4, wherein the second inclined surface includes the second contact portion.

6. the first contact portion includes a bent portion connecting the first straight surface and the second inclined surface, The lid for an underground structure according to claim 5 , wherein the second contact portion includes the bent portion.

7. A cover for an underground structure as described in claim 5 or 6, wherein the inclination angle of the second inclined surface relative to the first direction is smaller than the inclination angle of the first inclined surface relative to the first direction.

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