JP3758798B2 - Locking structure for lids for underground structures - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a locking structure for a lid for an underground structure that enables locking of a lid body and a receiving frame that supports the lid body.
In addition, the term “underground structure lid” as used in the present specification means a manhole cover, a large iron cover, a sewage culm lid, an electric power / Openable and closable joint gutter lids, power transmission iron lids, power distribution iron lids, buried underground pipes in waterworks and gas pipes, and their associated equipment to protect underground facilities equipment and underground cables in communications A fire hydrant lid, a water control valve lid, a gate valve lid, an air valve lid, a gas pipe lid, a water meter lid, etc., that function as an open / close door.
[0002]
[Prior art]
Conventionally, a lid for an underground structure composed of a lid body and a receiving frame that supports the lid body is locked by locking the lid body and the receiving frame to each other. A lock body provided on the back surface of the lid body and engaged with a locking portion formed on the inner surface of the receiving frame, or a locking portion provided on the inner surface of the receiving frame and provided on the back surface of the lid body The structure etc. which were made to engage with are known. Among these, as the latter example, one having a structure described in Japanese Utility Model Publication No. 60-20684 is known.
[0003]
In this structure, a substantially J-shaped locking body (lock body) is pivotally supported on a frame (receiving frame), and the weighting part is located outward from the pivot point and rises inward from the pivot point. A hook part (engagement part) protruding to the frame body side is formed through the rim, and a step part (locking part) that engages the hook part inside the peripheral part (edge winding) is formed on the iron lid (lid body). It is formed, and has a structure in which the hand key inserted into the keyhole is rotated and unlocked. Therefore, when the lid is opened by horizontal turning after unlocking, as in the structure in which the anchoring body is provided on the lower surface of the iron lid, the anchoring body contacts the road surface when the rib formed on the lower surface of the iron lid is low. Therefore, the problem that the lock body is damaged can be prevented. Moreover, since the iron lid does not become heavier than necessary by providing the frame body with the anchoring body having the weight portion, there is no hindrance to the opening.
[0004]
[Problems to be solved by the invention]
However, the locking structure described above is unlocked by a normal opening operation in which a T-shaped key with a tip is inserted into the keyhole and rotated horizontally to engage the tip with the lower surface of the iron lid. Therefore, a third party can easily open the lid. For this reason, there is a problem that foreign matter is illegally dumped in the manhole and the sewer pipe is clogged to block the sewer flow path, or the snow removed during snowfall is thrown into the manhole and the burden of sewage treatment increases.
Then, this invention aims at providing the locking structure of the lid | cover for underground structures which a third party cannot unlock easily.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, in the locking structure for a lid for an underground structure according to the present invention, a recess formed so as to open in the center direction on the inner peripheral surface of the receiving frame, and a shaft laid between both side walls of the recess. A lock main body pivotally supported so as to be movable between the locking position and the unlocking position in the axial direction and rotatable about the axial line, and a receiving frame at a position aligned with the lock main body in the closed state on the back side of the lid main body An engagement member formed so as to face the inner peripheral surface of the lock body, and in the locked state, the lock body is restrained from rotating in the unlocking direction at the lock position, and the locking portion of the lock body is When the lid main body is lifted, it is in a state of protruding from the inner peripheral surface of the receiving frame so as to lock the engaging portion of the engaging member of the lid main body. When the lid body is lifted up, the engaging member of the lid body can rotate the lock body in the unlocking direction. It is characterized by a door.
In the above configuration, when the lid is to be opened, the engaging portion of the lid body comes into contact with the locking portion of the lock body from below to rotate the lock body, but the lock body is in the locking position on the shaft. When the lock part is locked so as not to rotate in the unlocking direction, the locking part locks the engaging part, while the lock body is in the unlocked position on the shaft. The lock body can be rotated as it is to be unlocked and opened.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the lock body is configured to be pressed to the locking position side by the elastic member, thereby preventing the lock body from moving to the unlocking position against the lifting pressure generated in the underground structure, Locking is ensured.
In the present invention, when the lock body is positioned at least in the locking position, when it is rotated in the direction opposite to the locking direction, the lock body is returned to the locking posture by the urging force of the elastic member. When this is done, the lock body pushed into the recess can be reliably returned to the locked position, and the locked state can always be maintained in the closed state. In addition, even if the lock body swings due to the lifting pressure generated inside the underground structure in the locked state and tries to retreat into the recess, the locking force should be locked securely to prevent the lock body from swinging. Can do.
In the present invention, the engagement member is provided with a side wall that can be brought into contact with the locking portion of the lock body from the side surface, so that when the lid is opened, the lock body provided on the receiving frame is moved from the lock position to the unlock position. For this purpose, the lock body can be moved to the unlocked position on the side wall of the engaging member by rotating the lid body in the circumferential direction.
In the present invention, since the engaging member is provided on the back surface of the lid main body having the bag-shaped bar hole, the locking structure cannot be seen from the outside, and the lock main body cannot be operated with the bar.
In the present invention, the lock member can be seen from the open bar hole by providing the engagement member on the back surface of the lid body having the open bar hole and positioning the side wall of the engagement member on the open bar hole side. Disappear.
[0007]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
First, an embodiment of the locking structure for an underground structure lid according to the present invention will be described with reference to FIGS. The lid 1 for an underground structure closes a substantially annular receiving frame 2 provided on a ground part such as a vertical hole leading to an underground structure such as a sewer, and a substantially annular opening of the receiving frame 2 so that the opening can be closed or closed. The receiving frame 2 and the lid main body 3 are connected by a hinge (not shown) provided on a hinge receiving seat 4 of the receiving frame 2, and a bag is provided on the peripheral edge of the lid main body 3 opposite to the hinge. Shaped burl hole 15 is provided.
[0008]
The bag-shaped burl hole 15 is formed as a bag-shaped recess opened on the front surface side of the lid body 3, and the engaging member 5 according to the present invention is located below the bottom plate 151 of the bag-shaped burl hole 15 as shown in FIG. Further, it is provided so as to face the inner peripheral surface 21 of the receiving frame 2 in a closed state. In other words, the engaging member 5 is a substantially rectangular parallelepiped box-shaped member that includes an upper wall 52, an engaging portion 53, side walls 54a, 54b, and a back wall 54c and has an opening in one radial direction. The upper wall 52 is fixed to the back surface of the bottom plate 151 of the bag-shaped burl hole 15 with the opening 51 facing the inner peripheral surface 21 side. As shown in FIG. 6A, the engaging portion 102 of the lock main body 10 enters the engaging member 5 in the closed state. Details thereof will be described later.
[0009]
On the other hand, as shown in FIG. 4, a recess 6 is formed in a box shape on the inner peripheral surface 21 of the receiving frame 2 at a position substantially aligned with the engaging member 5 at the time of closing, with the center direction of the receiving frame 2 opened. As shown in FIG. 5, the recess 6 is provided with an insertion hole 61 c in one side wall 61 a, and the surface thereof is substantially the same as the inner peripheral surface 21 when the fixture 7 is attached to the corner of the other side wall 61 b. A stepped portion 62 is formed so as to be flush with each other, and screw holes 62b are formed in two upper and lower portions on the receiving frame inner surface 62a of the stepped portion 62.
[0010]
As shown in FIG. 4, the fixture 7 is an L-shaped thick plate material having the same length as the height of the concave portion 6, and through holes 7 b and 7 b are provided at two upper and lower positions in front of the long arm portion 71. An insertion hole 7 a is formed on the side surface 73, and an inclined surface 7 c is formed on the distal end side of the short arm portion 72.
[0011]
A shaft 8 through which the coil spring 9 and the lock body 10 are inserted is horizontally installed in the recess 6. The installation procedure is as follows. First, the coil spring 9 and the lock body 10 are inserted into the shaft 8, the tip of the shaft 8 on the coil spring 9 side is inserted into the insertion hole 61 c of the side wall 61 a, and the other end is inserted into the insertion hole 7 a of the fixture 7. Next, the fixture 7 itself is brought into contact with the receiving frame inner surface 62a of the stepped portion 62. In this state, the screws 63, 63 are inserted into the through holes 7b, 7b of the fixture 7, and the screw hole on the recess 6 side is inserted. This is a procedure of screwing to 62 b and fixing the fixture 7 to the stepped portion 62.
[0012]
When the fixing device 7 is fixed to the stepped portion 62, the upper wall 67 of the recess 6 is lowered by the height of the short arm portion 72 of the fixing device 7, and the lowered surface of the lock body 10 is described later. The locking portion 102 functions as the contact surface 72a that prevents the locking portion 102 from rotating counterclockwise in FIG.
[0013]
As shown in FIG. 4 and FIG. 6A, the lock body 10 has flat side surfaces 10a and 10b and a shaft hole that passes between the side surfaces 10a and 10b slightly above the longitudinal center of the side surfaces 10a and 10b. 104, the shaft 8 is inserted into the shaft hole 104, and the lock body 10 is supported by the shaft 8 so as to be movable in the axial direction and rotatable about the axis. The lock body 10 has a long weight portion 101 at the lower portion, and is suspended by its own weight so that it normally takes a locked posture (post-rotation posture). Further, the weight surface 101a that hits the front side of the weight portion 101 is a vertical surface when suspended, and at least does not protrude inward from the inner peripheral surface 21 of the receiving frame. The lock body 10 protrudes from the weight surface 101a at substantially the same height position as the shaft hole 104, and further protrudes inward from the receiving frame inner peripheral surface 21. Is formed.
[0014]
Therefore, when the engaging member 5 of the lid body 3 moves up and down with the opening / closing operation of the lid body 3, the engaging portion 53 formed at the lower end of the engaging member 5 is moved from below to the locking portion 102 of the lock body 10. Or it will always contact | abut from the top.
[0015]
Since the coil spring 9 is loosely fitted to the shaft 8 in a compressed state, the lock body 10 is always pressed against the side surface 73 (side wall 61b of the recess 6) of the fixing tool 7 by its restoring force. Further, both ends of the coil spring 9 are suspended, and when inserted into the shaft 8 and installed in the recess 6, one end 9 a abuts against the bottom wall 65 of the recess 6 and the other end 9 b is the lock body 10. Is lightly in contact with the slanted back surface 105. Therefore, in FIG. 6A, when the lock body 10 rotates clockwise, the coil spring 9 is twisted to generate a biasing force that pushes back the lock body 10, and the lock body 10 is locked by the biasing force. Acts to return to posture.
[0016]
Next, the effect | action of the lid | cover 1 for underground structures of the said structure is demonstrated using FIGS.
FIG. 7 shows a state in which the lid main body 3 is lowered to the receiving frame 2 in order to close the lid. Since the engaging member 5 is still separated from the lock main body 10 on the receiving frame side, the lock main body 10 is suspended by its own weight. Then, the locking posture is taken (FIG. 7A), and the side surface 10a of the fixing tool 7 is in contact with the side surface 73 of the fixing tool 7 by being pressed by the restoring force of the coil spring 9 (FIG. 7A). b)).
[0017]
When the lid body 3 is further lowered, as shown in FIG. 8, the engaging portion 53 at the lower end of the engaging member 5 comes into contact with the locking portion 102 of the lock body 10, and directly locks against the urging force of the coil spring 9. The main body 10 is rotated by pushing the weight portion 101 into the recess 6 toward the back wall 66 (FIG. 8A), and tries to pass through the locking portion 102.
[0018]
When the lid body 3 is further lowered and dropped, the engaging portion 53 passes through the locking portion 102 as shown in FIG. At that time, the lock body 10 returns to the locked posture due to its own weight and the urging force of the coil spring 9 so that the locking portion 102 enters the engagement member 5, and the lid body 3 is also supported by the receiving frame 2 to close the lid. Complete. Then, when the lid main body 3 is pulled up to open the lid from this state, as shown in FIG. 9, the engaging portion 53 comes into contact with the locking portion 102 and the lock main body 10 is rotated counterclockwise in the drawing. At this time, since the head 103 of the lock body 10 hits the contact surface 72a of the fixture 7, the rotation is prevented, and the engaging portion 53 is locked by the locking portion 102 to be locked.
[0019]
In the following description, when the lock body 10 is moved to the side surface 73 (side wall 61b of the recess 6) of the fixing tool 7 by the restoring force of the coil spring 9, that is, when the lid body 3 is pulled up as described above, The position where the head 103 of the lock body 10 hits the contact surface 72a and the rotation thereof is prevented is called the lock position, and the lock body 10 moves to the side wall 61a against the restoring force of the coil spring 9, that is, A position where the head portion 103 of the lock body 10 does not contact the contact surface 72a even if it is rotated and the rotation is not blocked is referred to as an unlocked position.
[0020]
When the lid is opened from the above-described locked state, after the bite between the lid body 3 and the receiving frame 2 is released with the dedicated bar, the lid body 3 (engagement member 5) is moved to the arrow A as shown in FIG. Rotate in the direction. By the rotation in the circumferential direction, the side wall 54a of the engaging member 5 comes into contact with the side surface 10a of the lock body 10 (the side surface of the locking portion 102), and the lock body 10 is rotated according to the rotation of the side wall 54a in the circumferential direction. Is moved from the locked position toward the unlocked position against the restoring force of the coil spring 9 (FIG. 10B).
[0021]
When the lid body 3 is slightly lifted while rotating in the circumferential direction, the engaging portion 53 comes into contact with the locking portion 102 of the lock body 10 as shown in FIG. Try to rotate. In this case, as shown in FIG. 11B, an inclined surface 7c formed on the fixture 7 is positioned above the lock body 10, and the head 102 of the lock body 7 abuts on the inclined surface 7c. If the lid body 3 (engagement member 5) continues to rotate and pull up in the direction of arrow A (FIG. 11 (c)), the rotation range of the lock body 10 increases accordingly. Then, when the lock body 10 is completely removed from the inclined surface 7c by the rotation of the lid body 3 (engagement member 5) in the direction of arrow A shown in FIG. 12C (FIG. 12B), the engagement portion 53 is engaged. Can pass through the locking portion 102 (FIG. 12A), and is unlocked.
When the engaging portion 53 passes, the lock body 10 moves to the locked position along the shaft 8 by the restoring force of the coil spring 9, and at this time, the head 103 of the lock body 10 is directed from the unlocked position to the locked position. The lock body 10 itself returns to the locked position smoothly while rotating around the axis under its own weight while abutting on the inclined surface 7c that descends downward, and the lock body 10 hangs down and stops at the locked position. Take.
[0022]
Thereafter, the lid body 3 is horizontally swiveled or vertically inverted around a hinge (not shown) to complete the lid opening. At this time, since the lid body 3 is not provided with the lock body 10 having the weight portion 101, the lid body 3 is not heavier than necessary, so that the horizontal turning or vertical reversal operation is facilitated.
[0023]
As described above, in this embodiment, the lid body 3 is rotated in the circumferential direction to move the lock body 10 from the locked position to the unlocked position, and then cannot be opened unless it is lifted upward. A third party cannot easily unlock, and the locking can be ensured.
[0024]
In addition, when the lock body 10 is pressed toward the locking position by the restoring force of the coil spring 9, the lock body 10 is moved to the unlocking position with respect to the lifting pressure generated in the underground structure such as a manhole. It can prevent and can maintain a locked state reliably.
[0025]
Furthermore, as shown in FIG. 8 (a), even when the lock body 10 is pushed into the recess 6 by the engaging portion 53 when closing the lid, the biasing force of the coil spring 9 returns the locking posture. In the closed state, the locked state can always be maintained. In the locked state, the lock body is swung by the lifting pressure generated in the underground structure, and the lock body 10 is moved into the recess 6 by the biasing force of the coil spring 9. In order to prevent retreating, it can be securely locked.
[0026]
In addition, the contact surface 72a is formed on the upper wall of the locking position of the recess 6, and the head 103 of the lock body 10 contacts the contact surface 72a when the lid is opened, so that the locked state is achieved. The lock body 10 can be reliably prevented from rotating in the unlocking direction, and can be locked firmly.
[0027]
Further, since the boundary between the upper wall surface of the unlocking position of the recess 6 and the contact surface 72a is an inclined surface 7c that descends from the unlocking position toward the locking position, the coil spring is moved from the unlocking position to the locking position after opening the lid. When the lock body returns by the restoring force of 9, the lock body 10 can be rotated smoothly and easily and moved to the lock position.
[0028]
Furthermore, since the engaging member 5 is provided with the side wall 54a that can come into contact with the locking portion 102 of the lock body 10 from the side surface, the lid cannot be opened unless the lock body 10 is moved from the locked position to the unlocked position. For those who know the structure, the lock body 10 can be moved from the locked position to the unlocked position by the operation of rotating the lid body 3 in the circumferential direction with a dedicated bar to open the lid. Therefore, the unlocking and opening of the lock body 10 can be performed by a series of operations.
[0029]
Further, since the engaging member 5 is provided on the back surface of the lid main body 3 having the bag-shaped bar hole 15, the locking structure cannot be seen from the outside, and the lock main body 10 cannot be operated with the bar, and a third party Can be surely prevented from being unlocked.
[0030]
In the above description, the lock body 10 is pressed using the coil spring 9, but another elastic member such as a leaf spring may be used instead of the coil spring. Further, the restoring force of the coil spring 9 presses the side wall 10a of the lock body 10 until it abuts against the fixture 7. However, if the lock body 10 is pressed from the unlocked position to the locked position, it is applied to the fixture 7. It is not necessary to press until it touches.
[0031]
Further, although the restoring force and the urging force are obtained by one coil spring 9, it may be configured to be obtained individually by an elastic member corresponding to each restoring force and urging force. For example, the urging force may be obtained by an elastic body provided between the lock body 10 and the back wall 66.
[0032]
Furthermore, although the contact surface 72a is formed by the fixture 7, the contact surface may be formed by changing the shape of the upper wall 67 of the recess 6.
[0033]
Moreover, although the shaft 8 is constructed using the insertion hole 7 a of the fixture 7, it may be constructed using the side wall of the recess 6.
Further, in the locking position, the head 103 of the lock body 10 is brought into contact with the contact surface 72a to prevent the lock body 10 from being unlocked and cannot be unlocked. It is formed at the same height as the upper wall 67 of the unlocking position, and the edge of the bottom wall 65 at the locking position is raised to be higher than the edge of the bottom wall 65 at the unlocking position. The lock body 10 may be prevented from rotating in the unlocking direction by bringing the lower portion of the weight surface 101a into contact with the raised edge.
Furthermore, the edge of the side wall 61b of the recess 6 or the edge of the side surface 73 of the fixture 7 is projected toward the side wall 61a, and the weight surface 101a of the lock body is brought into contact with the projected edge at the locking position. Thus, the lock body 10 may be prevented from rotating in the unlocking direction.
[0034]
Although the engaging member 5 forms the side wall 54a which contacts the side surface 10a of the lock body 10, the side wall 54a is not necessarily provided. When the side wall 54a is not provided, the lid opening operation is performed by moving the lock body 10 from the locking position to the unlocking position with a dedicated bar or the like and then lifting the lid body 3 upward with the dedicated bar.
[0035]
Further, the engaging member 5 is formed on the back surface of the lid main body 3 provided with the bag-like burl hole 15 having the bottom plate 151. However, as shown in FIG. 13, the lid provided with the penetrating open burl hole 16 without the bottom plate. You may comprise so that the side wall 54a of the engaging member 5 may be located in the open bar hole 16 side in the back surface of the main body 3. FIG. If comprised in this way, since the side wall 54a becomes a wall and the lock | rock main body 10 becomes invisible from the open bar hole 16, the unlocking method is not perceived.
[0036]
【The invention's effect】
As described above, according to the underground structure lid locking structure of the present invention, when the lock body is in the locked position, the lock body is restrained from rotating in the unlocking direction even if it is opened. Since the locking part of the lock body locks the engaging part of the lid body, the locking part is locked. On the other hand, when the lock body is in the unlocked position, the engaging part rotates the lock body. Since it is unlocked and can be opened, it cannot be opened unless the lock body is moved laterally from the locked position to the unlocked position, and third parties cannot easily unlock it. Can be.
[0037]
In addition, since the lock body is configured to be pressed to the locking position side by the elastic member, the lock body is not easily moved to the unlocking position even by the lifting pressure generated in the underground structure, so that the locking state is ensured. Can be maintained.
[0038]
In addition, when the lock body is at least in the locking position, if it is rotated in the direction opposite to the locking direction, it is returned to the locking posture by the urging force of the elastic member. The lock body that has been pushed in can be reliably returned to the locked position, and the locked state can be maintained at all times in the closed state, and the lock body can be shaken by the lifting pressure generated in the underground structure in the locked state. Even if it moves and tries to retreat into the recess, the urging force prevents the lock body from swinging, so that it can be locked securely.
[0039]
In addition, since the engaging member is provided with a side wall that can come into contact with the locking portion of the lock body from the side surface, the structure cannot be opened unless the lock body is moved from the locked position to the unlocked position. For those who know, the lock body can be opened by moving the lock body from the locked position to the unlocked position by rotating the lid body in the circumferential direction with the dedicated bar. Unlocking and opening the lid can be performed by a series of operations.
[0040]
In addition, since the engaging member is provided on the back surface of the lid body having a bag-shaped bar hole, the locking structure cannot be seen from the outside, and the lock body cannot be operated with the bar, and it is unlocked by a third party. Can be surely prevented.
[0041]
Further, since the engaging member is provided on the back surface of the lid main body having the open bar hole, and the side wall of the engaging member is positioned on the open bar hole side, the side wall of the engaging member is the wall of the lock main body. Since it cannot be seen from the open bar hole, the unlocking method is not detected.
[Brief description of the drawings]
FIG. 1 is a partially cutaway plan view showing an overall configuration of a manhole cover as an embodiment of a locking structure for a cover for an underground structure according to the present invention.
FIG. 2 is a perspective view showing an engaging member on the back surface of the lid body.
FIG. 3 is a perspective view showing a configuration of a recess formed in a receiving frame.
FIG. 4 is an exploded perspective view showing a configuration of a recess formed in the receiving frame.
5 is a cross-sectional view taken along the line II of FIG.
6A and 6B are views showing the positional relationship between the engaging member and the lock body when the lid is closed, where FIG. 6A is a cross-sectional view, FIG. 6B is a front view showing only the receiving frame side, and FIG. It is a top view with an engaging member.
7A and 7B are views showing the positional relationship between the engaging member and the lock body at the start of closing the lid, wherein FIG. 7A is a cross-sectional view, FIG. 7B is a front view showing only the receiving frame side, and FIG. It is a top view with an engaging member.
FIGS. 8A and 8B are views showing the positional relationship between the engaging member and the lock body immediately before the closing of the lid, in which FIG. 8A is a cross-sectional view, FIG. 8B is a front view showing only the receiving frame side, and FIG. It is a top view with an engaging member.
FIGS. 9A and 9B are views showing the positional relationship between the engaging member and the lock body in the locked state after the closing of the lid, where FIG. 9A is a cross-sectional view and FIG. 9B is a front view showing only the receiving frame side;
FIGS. 10A and 10B are views showing the positional relationship between the engaging member and the lock body when the lid body 3 is rotated in the circumferential direction at the start of opening of the lid, where FIG. 10A is a cross-sectional view and FIG. (C) is a top view of a receiving frame and an engaging member.
11A and 11B are views showing the positional relationship between the engaging member and the lock body when the lid body is slightly lifted when the lid is opened, FIG. 11A is a cross-sectional view, and FIG. 11B is a front view showing only the receiving frame side; c) is a plan view of the receiving frame and the engaging member.
FIGS. 12A and 12B are views showing the positional relationship between the engaging member and the lock body immediately before unlocking is completed, in which FIG. 12A is a cross-sectional view, FIG. 12B is a front view showing only the receiving frame side, and FIG. It is a top view with an engaging member.
FIG. 13 is a view showing a case where an engagement member is provided on the back surface of the lid body having an open bar hole.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cover for underground structures 2 Receiving frame 21 Inner peripheral surface 3 Lid main body 5 Engagement member 51 Opening part 52 Upper wall 53 Engagement part 54a, 54b Side wall 6 Recess 61a, 61b Side wall 62 Step part 65 Bottom wall 66 Back wall 67 Top Wall 7 Fixing tool 7c Inclined surface 72a Contact surface 8 Shaft 9 Coil spring (elastic member)
9a One end portion 9b Other end portion 10 Lock body 101 Weight portion 101a Weight surface 102 Locking portion 103 Head portion 104 Shaft hole 105 Oblique back surface 15 Bag-shaped burl hole 16 Open burl hole

Claims (6)

A recess formed in the inner peripheral surface of the receiving frame so as to open in the center direction, and a shaft extending between both side walls of the recess can be moved to a locked position and an unlocked position in the axial direction and can be rotated about the axis. A lock body pivotally supported on the rear surface of the lid body, and an engaging member formed so as to face the inner peripheral surface of the receiving frame at a position aligned with the lock body in the closed state on the back side of the lid body. The lock body is restrained from rotating in the unlocking direction at the locked position, and the locking portion of the lock body engages the engaging portion of the engaging member of the lid body when the lid body is lifted. It is in a state of protruding from the inner peripheral surface of the receiving frame so as to stop, and when unlocking, the lock body is positioned at the unlocking position, and when the lid body is lifted, the engaging member of the lid body is locked Can be rotated in the unlocking direction,
A structure for locking a lid for an underground structure. The lock body is pressed to the locking position side by an elastic member,
The locking structure of the cover for underground structures of Claim 1 characterized by the above-mentioned. When the lock body is positioned at least in the locking position, and is rotated in the direction opposite to the locking direction, the locking body is returned to the locking posture by the urging force of the elastic member.
The locking structure for a lid for an underground structure according to claim 1 or 2. The engaging member is provided with a side wall capable of coming into contact with the locking portion of the lock body from the side surface.
The locking structure for a cover for an underground structure according to any one of claims 1 to 3. Provided the engagement member on the back surface of the lid body having a bag-like bur hole,
The locking structure for a lid for an underground structure according to any one of claims 1 to 4. The engagement member is provided on the back surface of the lid body having an open bar hole, and the side wall of the engagement member is positioned on the open bar hole side.
The locking structure for a lid for an underground structure according to claim 4.

Images