JPH10168923A - Locking structure of cover for underground structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide locking structure, in which a cover can be opened without requiring unlocking operation separate from cover opening operation when the cover must be opened and cannot be unlocked by the uplift of a turbulent flow in an underground structure. SOLUTION: A support shaft 12 is provided transversely to brackets 11, 11 droopingly provided to the rear of a cover body 3 while being faced to the recessed section 7 of a receiving frame 2, and a locking hook 15 is supported movably to the support shaft 12 in the vertical direction through a sliding groove 17. An engaging pawl section 16 housed in the recessed section 7 and engaged with a retaining section 9 and locked and an abutting section 15d being abutted against the internal surface 2a of the receiving frame 2 and functioning as a tilting supporting point at the time of cover opening operation are formed to the locking piece 15. A tilting impossible section at an upper end and a lower end and a first tilting section 18 being inclined around the support shaft and releasing a lock at the time of cover opening operation and a second tilting section 19 being slanted around the support shaft and locking the lock at the time of cover closing operation are formed to the sliding groove 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locking structure for a lid for an underground structure, and more particularly, to a locking structure for a lid for an underground structure capable of locking a lid body and a receiving frame supporting the lid body. Incidentally, the term "cover for underground structure" as used in the specification of the present application refers to a large iron cover, a manhole cover, which closes an opening through an underground buried object in a sewer, an underground structure facility, and the ground.
Sewage basin lids, openable and closable iron lids to protect underground facilities equipment and underground cables in power and communications, iron lids for power transmission, iron lids for power distribution, buried conduits under water roads and underground pipes for water supply and gas piping, and their accessories A fire hydrant cover, a water control valve cover, a partition valve cover, an air valve cover, a gas pipe cover, a water meter cover, and the like, which function as an opening / closing door connecting the device and the ground.

[0002]

2. Description of the Related Art Various underground structure lids are provided with a receiving frame which is installed at the upper end of an underground structure and opens to the ground such as a road surface, and a lid body which covers the opening by taper fitting or the like to the receiving frame. The lid body is attached to the receiving frame by a hinge structure, so that when the lid is opened, the receiving frame can be turned in a horizontal plane or turned over to the ground side, and a locking structure for locking the lid body and the receiving frame is provided. Things are common.

As a locking structure for locking the receiving frame and the lid body, there is, for example, one described in Japanese Utility Model Publication No. 63-15391. This locking structure prevents the locking hook having a threaded rod penetrating through the lid body in a lid for an underground structure in which a locking hook engaged with the receiving frame and locked is rotatably supported on the back surface of the lid body. Attach the device, the screw is formed with screws at the upper and lower ends of the screw to be screwed to the lid body, and the lower side of the screw is brought into contact with the locking hook at the time of locking, the locking hook swings by the swing prevention device This prevents the lid from being unlocked due to the turbulent lifting pressure inside the underground structure, thereby maintaining the locked state and preventing the lid body from scattering.

[0004]

In the above-described locking structure, the swing preventing device surely prevents the locking hook from swinging to prevent the cover main body from scattering. If necessary, first release the contact between the swing prevention device and the locking hook, then insert the burl of the lid opening jig into the burl hole, press the burl pressure receiving portion of the locking hook, and unlock it. In addition, it is necessary to release the biting force between the lid body and the receiving frame to open the lid, so that the operation of opening the lid is troublesome. Furthermore, when it is necessary to open the lids for underground structures such as fire hydrant lids, power distribution lids, gas pipe iron lids, etc. in an emergency, it takes time to open the lid and can respond quickly. There is no problem.

[0005] The present invention has been made in view of the above points, and when it is necessary to open the lid without unlocking due to turbulent lifting pressure inside the underground structure, a separate opening operation is required. An object of the present invention is to provide a locking structure for a lid for an underground structure, which can be opened without requiring an unlocking operation.

[0006]

According to the present invention, there is provided a lid for an underground structure having a locking means provided on a back surface of a lid body and a locking means for engaging the locking means in a receiving frame supporting the lid body. In the locking structure, the locking means includes a concave portion provided on the inner surface of the receiving frame, and a locking portion projecting above the concave portion.
The locking means comprises a support shaft laterally fixed to a bracket vertically provided on the back surface of the lid body facing the recess from a lower portion of the concave portion and protruding into the receiving frame. A locking hook through which the support shaft is inserted. The locking hook is housed in the recess when the support shaft is inserted and the slide groove is movable in the vertical direction. An engaging claw that is engaged with and locked by the locking portion when the lid body is lifted by lifting pressure or the like; and a locking hook above the support shaft when the locking hook is placed on the shelf in the closed state. Located in
A tilting portion formed at least in the middle of a slide groove for taking in the support shaft and tilting the locking hook around the support shaft at the time of opening / closing the lid body, and the tilting portion making the locking hook incapable of tilting around the support shaft. A non-tiltable portion formed in the slide groove excepting, and a contact portion which comes into contact with the inner surface of the receiving frame at the time of the lid opening operation and serves as a tilting fulcrum of the locking hook are provided.

[0007] With this configuration, in the closed state, the locking hook does not tilt due to the turbulent lifting pressure inside the underground structure, and the lid main body supported by the receiving frame is pushed upward. Then, the support shaft moves upward in the slide groove of the locking hook together with the lid main body, and comes into contact with the upper end of the sliding groove to lift the locking hook upward. Since the locking hook does not tilt when the support shaft is located at the non-tiltable portion except the tilting portion formed in the slide groove, the engaging claw portion housed in the concave portion is engaged with the locking portion. Thereby, the lid body is locked to the receiving frame and is prevented from scattering.

When the lid body is lifted obliquely upward by the lid opening operation, the support shaft moves up in the slide groove of the locking hook to enter the tilting portion, and the contact portion contacts the inner surface of the receiving frame to tilt the fulcrum. And the lower portion of the locking hook is tilted about the support shaft so as to move toward the center of the receiving frame, and the engaging claw is disengaged from the locking portion and unlocked. This allows the lid body to be opened.

At the time of closing the cover, the support shaft is inserted into the tilting portion of the locking hook, and the locking hook is tilted around the support shaft.
The engaging claw is lowered so as to come into contact with the inner surface of the receiving frame, and is further lowered over the locking portion. When the lid main body is placed on the receiving frame, the locking hook is placed and supported on the shelf, and the engaging claw is housed in the recess and is opposed to the engaging portion so as to be engageable.

[0010]

In the present invention, the tilting portion forms a first tilting portion for taking in the support shaft during the lid opening operation in the middle of the slide groove, and has a lower end for taking in the support shaft during the lid closing operation. Two tilting portions are formed, and in a closed state, the support shaft is located at a non-tiltable portion between the first tilting portion and the second tilting portion. With this configuration, the locking hook in the closed state is prevented from tilting,
When the locking hook is placed on the upper edge of the receiving frame during the closing operation and the lid body is dropped obliquely downward into the receiving frame, the support shaft is taken into the second tilting portion and the locking hook is tilted. The cover can be easily closed by being dropped into the inside.

[0011] In the present invention, the support shaft is a rectangle whose cross-sectional shape is slightly narrower than the slide groove. By making the cross-sectional shape of the support shaft rectangular, the locking hook moves up and down along the slide groove of the locking hook to prevent the locking hook from tilting. Preferably, by making the cross-sectional shape of the support shaft a vertically long rectangle along the longitudinal direction of the slide groove, tilting of the locking hook can be favorably prevented.

Further, in the present invention, the abutment portion of the locking hook is formed at substantially the same height or slightly lower than the tilting portion formed in the middle of the slide groove. By providing the contact portion at such a position, when the cover comes into contact with the inner surface of the receiving frame and acts as a tilting fulcrum of the locking hook, the locking hook can be easily tilted. Further, in the present invention, the tilting portion has a configuration in which the inner surface of the slide groove on the engaging claw side is cut out in a substantially arc shape, or a corner portion of the support shaft that contacts the inner surface of the tilting portion is a curved surface. With this configuration, it is easy to tilt the locking hook around the support axis during the opening operation and the closing operation.

Further, the inner surface of the tilting portion is formed in a substantially circular arc shape, and the corner of the support shaft abutting on the inner surface is formed as a curved surface, so that both can smoothly slide, and the locking hook can be tilted about the support shaft. Becomes easier. (Embodiment) FIG. 1 is a sectional view showing a locking structure of a lid for an underground structure according to the present invention. In FIG. 1, underground structure lid 1
Has a circular shape in plan view formed by the receiving frame 2 and the lid main body 3, and the upper surface thereof is installed flush with the ground surface (GL). The receiving frame 2 forms a fitting surface 2a with a lid main body 3 having an inner peripheral upper surface tapered, and the lid main body 3 reduces the outer peripheral surface of the rim winding 3a into a tapered shape to form a fitting surface 2a. Abutting. The lid main body 3 is connected to the receiving frame 2 by a hinge structure (not shown) so as to be openable and closable. The cover can be opened. A locking structure 4 is provided between the receiving frame 2 and the lid body 3, the locking means 5 being provided on the receiving frame 2 side at a position opposite to the hinge structure and the locking means 6 being provided on the lid body 3 side. Is provided.

The above-described hinge structure is, for example, a receiving frame 2
An underground structure lid having a structure in which an annular hinge seat protrudes from the inner periphery of the base member and into which a hinge hardware swingably attached to the back surface of the lid body 3 is inserted is used. This hinge structure has a certain degree of freedom in the front-rear direction with respect to the hinge seat in a state where the hinge hardware is inserted into the hinge seat.In the present embodiment, by providing such a hinge structure, At the time of opening the lid, the lid main body 3 can be pulled up obliquely upward to the front side. Further, the lid body 3 is pushed straight up by the length of the hinge structure when receiving the turbulent lifting pressure inside the underground structure.

As shown in FIG. 2, the receiving frame 2 has a fitting surface 2a for fitting and supporting the lid body 3 on the inner peripheral upper surface thereof, and a lower portion of the receiving frame 2 with a stepped portion 2c therebetween. An inner peripheral surface 2b having a slightly smaller diameter is formed. The locking means 5 is provided on the inner peripheral surface 2b.
, A shelf 8 protruding substantially horizontally toward the inside of the receiving frame 2 at the lower end of the opening of the concave 7, and projecting along the circumferential direction at the upper end of the opening of the concave 7. And a locking portion 9. The shelf 8 has a length that does not hinder the worker from entering or leaving the receiving frame 2.

As shown in FIG. 3, the lid main body 3 is provided with a burr hole 3c bulging downward in a bag-like shape at a position corresponding to the locking means 5 of the receiving frame 2 at a peripheral edge of the upper surface 3b. And
A pair of brackets 11, 11 are vertically provided on the rear surface of the lid main body 3 at the left and right sides of the bag portion 3d forming the burl hole 3c and slightly inside the rim winding 3a. As shown in FIG. 1, these brackets 11, 11 are spaced apart from and opposed to the recessed portions 7, and the lower ends are slightly separated from the shelf 8 in a closed state in which the lid body 3 is fitted and supported in the receiving frame 2. A polygonal hole, for example, a rectangular hole 11a whose height is slightly longer than its width is formed in the lower part of each bracket 11 so as to face each other.

A support shaft 12 which is inserted into a slide groove 17 of a locking hook 15 which will be described later is provided laterally in the square hole 11a. The support shaft 12 has a rectangular prism having a rectangular cross section that fits into the square hole 11 a of the bracket 11 and has the same length as the outer dimension of the bracket 11.
a, a head 12b is formed at one end, and a screw portion 12c is formed at the other end. A corner formed by the upper surface of the shaft portion 12a and the outer surface facing the outside of the lid body 3 is chamfered over the entire length to form a curved surface 12d.

The locking hook 15 is connected to the brackets 11 and 1 on both sides.
1, the side portions 15b, 15b are raised on both sides of the upper portion of the hook body 15a, and a storage space 15c is provided between them. The storage space 15c stores a bag portion 3d that forms a burl hole 3c that is a bag hole when the lid body 3 is closed as described later. Locking hook 1
5 has a lateral width set slightly shorter than the opening width of the concave portion 7, a substantially L-shaped engaging claw portion 16 protrudes forward at a lower portion of the front surface, and faces the locking portion 9 in the concave portion 7. And can be stored.

The locking hook 15 is provided with a vertically extending slide groove 17 in the hook body 15a and the side portions 15b, 15b rising upward. This slide groove 17
The width of the support shaft 12 is slightly wider than the width of the vertical cross-sectional shape, and the support shaft 12 can be moved up and down with a slight gap. On the inner surface 17a of the slide groove 17 on the locking claw portion 16 side (front side), a first tilting portion 18 is cut out at an upper portion and a second tilting portion 19 is cut at a lower end in a substantially arc shape. The first tilting portion 18 can take in the support shaft 12 when the lid is opened, and the second tilting portion 19 can tilt the locking hook 15 around the support shaft 12 when the lid is closed. That is, as shown in FIG. 5, the first tilting portion 18 has an upper surface
a has an inclined surface 18b at the bottom. Further, the second tilting portion 19 has a fan shape in which the upper surface 19a has an arc shape.

The upper end of the slide groove 17 is provided with a non-tiltable upper portion 17b.
A non-tiltable portion 17c is formed between the tilting portion 19 and the locking hook 15 so as not to tilt around the support shaft 12 when the support shaft 12 is positioned at the upper and lower tiltable portions 17b and 17c. ing. Both sides 15b, 15b of locking hook 15
In the upper part of the front surface, contact portions 15d, 15d are formed so as to bulge forward at a height position substantially corresponding to the first tilting portion 18. These contact portions 15d, 15d are formed such that the support shaft 12 is taken into the first tilting portion 18 of the locking hook 15 during the opening operation, and the locking portion 9 formed at the upper end of the opening of the concave portion 7 formed in the receiving frame 2 and The locking hook 15 is a tilting fulcrum when the locking hook 15 tilts around the support shaft 12 by successively abutting and sliding on the fitting surface 2a.

As shown in FIGS. 1, 3 and 4, the locking hook 15 is arranged between the brackets 11 and 11 so that the locking claw 16 is housed in the recess 7 and The shaft portion 12a has a square hole 11a of the bracket 11 on one side, a slide groove 17 of the locking hook 15, and a square hole 1 of the bracket 11 on the other side.
1a is inserted, a nut 14 is screwed into the screw portion 12c via a washer 13, and fixed by the head portion 12b and the nut 14.

Further, as shown in FIG.
As shown by a dashed line 12 ′, it is possible to enter the second tilting portion 19 at a position in contact with the lower end surface of the slide groove 17, and the support shaft 12 is tilted at the lower end position of the first tilting portion 18. It is possible to enter the first tilting portion 18 along the surface 18b. The locking hook 15 can be tilted (rotated) with respect to the support shaft 12 when the support shaft 12 enters the first tilt portion 18 or the second tilt portion 19, and is shown at another position, that is, by a solid line. 17c in which the support shaft 12 is formed substantially in the middle of the slide groove 17 as described above.
, Or as shown by the two-dot chain line 12 ″, the upper tilt immobility portion 17 b formed at the upper end of the slide groove 17.
When it is located at, it cannot be tilted.

As shown in FIG. 1, in the locking structure 4 of the lid 1 for an underground structure, the locking hook 15 hangs down by its own weight when the lid body 3 is supported and fitted in the receiving frame 2 and closed. The engaging claw 16 is placed on the shelf 8, enters the concave portion 7, and is located below the locking portion 9 so as to be able to engage with the locking portion 9. The contact portion 15 d of the locking hook 15 slightly contacts the end face of the locking portion 9. The contact portion 15
d does not need to be in contact with the end face of the locking portion 9 and may be slightly separated. Further, in such a closed state, the support shaft 12 is not allowed to tilt downward so that there is a gap between the support shaft 12 and the lower end of the slide groove 17 formed in the locking hook 15.
7c, the upper end of the locking hook 15 and the lid body 3
Has a gap wider than the gap between the support shaft 12 and the lower end of the slide groove 17.

Next, the operation of the locking structure 4 will be described with reference to FIGS. First, the locking operation of the locking structure 4 when the turbulent lift generated inside the underground structure acts on the lid body 3 to push it up will be described with reference to FIGS. FIG. 6A shows a state in which the lid body 3 is fitted and supported on the receiving frame 2. The locking hook 15 is placed on the shelf 8 by its own weight, the engaging claw 16 enters the recess 7, and faces the locking portion 9 below the locking portion 9. In this state, the lower surface of the support shaft 12 is
7 is located slightly above the lower end surface of the support shaft 7, and the upper portion of the support shaft 12 is located at the downwardly tiltable portion 17c, so that the locking hook 15 is prevented from tilting.

In this state, when a turbulent lifting pressure acts on the back surface of the lid body 3, the locking hook 15 is not only less likely to receive the lifting pressure by the shelf portion 8, but also the support shaft 12 is moved to the downwardly tiltable portion 17c. Since the lid body 3 is located in a stationary state, the lid body 3 is pushed upward just above as shown by an arrow A in FIG.
Move inside 7. The lid body 3 is further pushed up (c)
When the support shaft 12 is lifted off the receiving frame 2 as shown in FIG.
7b.

When the lid body 3 is further pushed up, the supporting shaft 12 raises the locking hook 15 directly upward as shown in FIGS. At this time, the locking hook 15 is pulled up while maintaining the substantially upright state while the tilting is prevented because the support shaft 12 is located in the upward tilting impossible portion 17 b, and the engaging claw 16 is moved straight inside the recess 7. Move up. Then, when the engaging claw 16 of the locking hook 15 engages with the locking portion 9 as shown in FIG. 5 (f), the locking hook 15 is locked to prevent the lid body 3 from floating, and the underground structure The scattering of the lid body 3 due to the internal turbulent lifting pressure is prevented.

Next, the unlocking operation of the locking structure 4 when the lid body 3 is opened will be described with reference to FIGS. 7 (a) to 7 (f). In FIG. 1, the worker inserts the tip of a dedicated bar (not shown) into the bar hole 3c of the
7 and the lid body 3 is released, and FIG.
When the lid body 3 is pulled up obliquely upward while being pulled toward the near side as shown by, the support shaft 12 moves the sliding groove 17 of the locking hook 15 as the lid body 3 is pulled up diagonally upward.
It moves upward while sliding on the inner surface 17a of the lower tiltable portion 17c, and slides on the inclined surface 18b of the first tilting portion 18 to enter the first tilting portion 18. On the other hand, the locking hook 15
It is still placed on the shelf 8, the engaging claw 16 faces the locking portion 9, and the contact portion 15 d contacts the end face of the locking portion 9.

When the lid body 3 is further pulled obliquely upward, the arc-shaped upper surface 18a formed on the first tilting portion 18 slides on the curved surface 12d formed on the support shaft 12 as shown in FIG. The support shaft 12 starts lifting the locking hook 15 as described above. At this time, the locking hook 15 receives the force of turning in the counterclockwise direction in the drawing with the first tilting portion 18 as the point of force and the contact surface 15d contacting the end surface of the locking portion 9 as the tilting fulcrum, and the front lower end edge Tilts backward (counterclockwise) while sliding on the shelf 8. When the lid main body 3 is further pulled up obliquely upward, the locking hook 15 further tilts as shown in FIG. 4C, and the engaging claw 16 comes out of the concave portion 7 to disable the engagement with the locking portion 9. Is done. At this time, the front upper end edge of the locking hook 15 abuts on the fitting surface 2a, and the tilting of the locking hook 15 is stably held.

As shown in FIG. 5D, the abutting portion 15d of the locking hook 15 abuts on the fitting surface 2a from the end face of the locking portion 9 as the lid body 3 is pulled up obliquely upward. Face 2a
Is pulled up while maintaining the above tilting state while sliding. Then, the engagement claw portion 16 passes through the inside of the locking portion 9 (inward of the receiving frame 2) with a slight gap from the locking portion 9.

The lid body 3 is further pulled obliquely upward,
(E) When the contact portion 15d of the locking hook 15 comes off the fitting surface 2a of the receiving frame 2 as shown in FIG.
It is pulled up while abutting on a, and is placed on the upper end of the receiving frame 2 as shown in FIG. Thereafter, the lid body 3 is opened by horizontal turning or inversion by a normal opening operation.

The burl hole 3c of the lid body 3 is formed in a bag shape, so that the locking hook 15 cannot be directly operated with a burl when the lid is opened. Locking structure 4 without opening the lid
Cannot be unlocked and opened. That is, even if a person who is not a person skilled in the art, such as a maintenance manager of the underground structure, attempts to lift the lid main body 3 right above, the lid is locked and cannot be opened as shown in FIG. However, said person skilled in the art:
When the lid needs to be opened, the lid can be easily unlocked and opened by a series of opening operations as described above, that is, without requiring an unlocking operation different from the opening operation.

Next, the locking operation of the locking structure 4 when the lid is closed will be described with reference to FIGS. 8 (a) to 8 (f). Lid body 3
First, the worker lifts the lid body 3 and places the locking hook 15 upright on the upper end of the receiving frame 2 as shown in FIG. In this state, the upper end surface of the locking hook 15 is slightly separated from the back surface of the lid main body 3, and the support shaft 12 is disengaged from the downwardly tiltable portion 17c and the lower surface contacts the lower end surface of the slide groove 17 of the locking hook 15. The locking hook 15 can be tilted by being able to enter the second tilting portion 19.

Next, the operator drops the lid body 3 obliquely downward into the receiving frame 2 as shown by the arrow C in FIG. The locking hook 15
As the lid body 3 is pushed, it slides on the upper end surface of the receiving frame 2,
(B) When the lower surface is displaced from the upper end surface as shown in the figure, the front lower end edge in contact with the upper end of the opening of the receiving frame 2 is tilted clockwise (rearward) in the figure as a tilting fulcrum.
2 enters the second tilting portion 19. As the lid body 3 is dropped obliquely downward (c) and (d), the locking hook 15 descends while the engaging claw portion 16 slides on the fitting surface 2a of the receiving frame 2 as shown in FIGS. e) The rear lower edge of the locking hook 15 contacts the shelf 8 as shown in the figure.

Then, as shown in FIG. 3 (f), when the lid body 3 is fitted into the receiving frame 2 and closed, the locking hook 15 is opened with the engaging claw portion 16 upward in a substantially L-shape. Because of this shape, it easily gets over without engaging with the locking portion 9, rotates in the counterclockwise direction (front side) in the drawing, and the lower surface comes into contact with the shelf 8 and is supported vertically. Then, the engaging claw portion 16 of the locking hook 15 is housed in the concave portion 7, is positioned below the locking portion 9, and is locked so as to be engageable with the locking portion 9. In this way, the operator supports the lid frame 3 while supporting the lid frame 3 when closing the lid.
Instead, the lid main body 3 is placed so that the locking hook 15 is placed upright on the upper end of the receiving frame 2, and is slid into the receiving frame 2 (dropped obliquely downward). Locking can be performed simultaneously by a series of operations of closing the lid.

Although the second tilting portion 19 is provided at the lower end of the slide groove 17 of the locking hook 15 as a tilting portion to facilitate the closing operation, the tilting portion may be only the first tilting portion 18. In this case, the lid closing operation is performed by slightly lifting the lid main body 3 from the state where the locking hook 15 is placed on the upper end of the receiving frame 2.
2 is positioned on the first tilting portion 18, the locking hook 15 is tilted by hand, and the locking hook 15 is slid on the inner peripheral surface 2a of the receiving frame to close the lid.

In the above embodiment, the burl hole 3c of the lid body 3 is a bag-shaped burr hole. However, the invention is not limited to this, and may be an open bale hole which has been generally used. However, a bag-shaped burl hole as in the embodiment is preferable in that it can prevent the lid from being opened by a third party other than those skilled in the art and can prevent intrusion of rainwater and the like.

In the above embodiment, the support shaft 12
In order to make the locking hook 15 movable in the vertical direction, and to make the locking hook 15 unable to tilt at the lower tilting disabled portion 17c formed at an intermediate position of the slide groove 17 and the upper tilting disabled portion 17b formed at the upper end, the shaft portion 12a is tilted. Although the cross-sectional shape was a rectangular column having a rectangular shape elongated in the vertical direction along the longitudinal direction of the slide groove 17, the shape is not limited to this, and other shapes such as a square or an oval shape long in the longitudinal direction of the slide groove 17 are used. It is good.

Further, in the embodiment, the lid body 3 and the receiving frame 2 are connected by a hinge structure, and the locking structure 4 is provided on the opposite side.
A locking structure 4 may be provided instead of the hinge structure.

[0039]

According to the locking structure of the lid for an underground structure of the present invention, the lid has a tilting portion provided in the middle of the slide groove and a contact portion which comes into contact with the inner surface of the receiving frame when the lid is opened. When the main body is pulled out of the receiving frame, the support shaft inserted in the slide groove is taken into the tilting part, and the abutment part comes into contact with the inner surface of the receiving frame, causing the locking hook to be unlocked by tilting, and the lid is opened. The cover can be easily opened by a series of operations. In addition, since the locking hook is formed in the slide groove excluding the tilting portion so that the locking hook cannot tilt around the support shaft, when the lid body floats due to the lifting pressure in the underground structure, the support shaft is at the upper end of the slide groove. Since it is located, the locking hook is not unlocked, and the cover main body is locked to the receiving frame 2 so that scattering can be reliably prevented.

Further, the support shaft is located in a non-tiltable portion formed below a tiltable portion formed in the middle of the slide groove when the locking hook is placed on the shelf, so that the lid is in the closed state. In this case, since the tilting of the locking hook is prevented, the locking hook is stably held in a lockable state. Also, by having the second tilting portion at the lower end of the slide groove, the lid is not supported by the receiving frame while supporting the lid body when the lid is closed,
The locking hook is tilted by taking the support shaft into the second tilting portion simply by placing the locking hook upright on the upper end of the receiving frame and sliding (dropping) the lid body inside the receiving frame as it is. Therefore, the lid can be easily closed and the locking can be performed simultaneously.

Further, by making the cross section of the support shaft a rectangle slightly narrower than the slide groove, it is possible to securely and easily support the locking hook with a simple structure without tilting. Further, by forming the abutting portion of the locking hook at substantially the same height position or a slightly lower position as the tilting portion formed in the middle of the slide groove, the locking hook can be easily tilted around the support axis.

Further, the tilting portion may be configured such that the inner surface of the slide groove on the side of the engaging claw is cut out in a substantially arc shape, or the corner portion of the support shaft abutting on the inner surface of the tilting portion may be formed as a curved surface, thereby locking the hook. The tilting of the tilting portion around the support axis becomes smooth, and the unlocking operation at the time of opening the lid and the locking operation at the time of closing the lid are reliably performed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a locking structure of a lid for an underground structure according to the present invention.

FIG. 2 is a perspective view of a locking means provided on a receiving frame of the locking structure of FIG.

FIG. 3 is an exploded perspective view of a locking means provided on a lid body having the locking structure of FIG. 1;

FIG. 4 is a front view of a state where the locking means of FIG. 3 is assembled.

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

FIG. 6 is an explanatory diagram showing a locking operation when the locking structure shown in FIG. 1 is locked.

FIG. 7 is an explanatory view showing an unlocking operation when the locking structure shown in FIG. 1 is opened.

FIG. 8 is an explanatory view showing a locking operation when the locking structure shown in FIG. 7 is closed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cover for underground structures 2 Receiving frame 2a Fitting surface 3 Lid body 3a Edge winding 3c Burl hole 3d Bag part 4 Locking structure 5 Locking means 6 Locking means 7 Recess 8 Shelf 9 Locking part 11 Bracket 11a Square hole 12 Support Shaft 15 Locking hook 15a Hook main body 15b Side 15c Storage space 15d Abutment 16 Engagement claw 17 Slide groove 17b Non-tiltable upper part (non-tiltable part) 17c Non-tiltable lower part (non-tiltable part) 18 First tilting part (Tilt part) 19 Second tilt part (tilt part)

Claims (6)

[Claims] 1. A locking structure for a cover for an underground structure, wherein a locking means is provided on a back surface of a lid body, and a locking frame for supporting the lid body is provided with locking means for engaging with the locking means. Comprises a concave portion provided on the inner surface of the receiving frame, a locking portion protruding above the concave portion, and a shelf protruding inwardly from the lower portion of the concave portion to the receiving frame. A support shaft laterally fixed to the bracket that is vertically provided on the back surface of the lid body and facing the recess, and a locking hook through which the support shaft is inserted; and the locking hook is inserted through the support shaft. A sliding groove which is movable in the vertical direction and is engaged with the locking portion when it is placed on the shelf and is received in the concave portion and is engaged with the locking portion when the lid body is lifted by lifting pressure or the like. A claw portion and, when the locking hook is placed on the shelf portion in a closed state, above the support shaft; And a tilting portion formed at least in the middle of a slide groove for taking in the support shaft and tilting the locking hook around the support shaft when the lid body is opened and closed, and making the locking hook incapable of tilting around the support shaft. A basement, wherein a non-tiltable portion formed in a slide groove excluding the tilting portion, and a contact portion serving as a tilting fulcrum of the locking hook provided in contact with an inner surface of the receiving frame during the opening operation are provided. Locking structure for structure lid. 2. The tilting portion forms a first tilting portion which can take in a support shaft in the middle of the slide groove during a lid opening operation to tilt the locking hook around the support shaft, and a lower end of the slide groove. A second tilting portion for receiving the support shaft at the time of the lid closing operation and tilting the locking hook around the support shaft, and in the closed state, the support shaft is connected to the first tilting portion and the second tilting portion.
The locking structure for a lid for an underground structure according to claim 1, wherein the locking structure is located at a non-tilt portion between the tilt portion and the tilt portion. 3. The underground structure lid locking structure according to claim 1, wherein the support shaft has a rectangular shape having a cross section slightly narrower than the slide groove. 4. The apparatus according to claim 1, wherein the abutment portion of the locking hook is formed at a position substantially equal to or slightly lower than a tilting portion formed in the middle of the slide groove. A locking structure for a lid for an underground structure as described in the above. 5. The underground structure according to claim 1, wherein the tilting portion is formed by cutting an inner surface of the slide groove on the side of the engaging claw into a substantially arc shape. Locking structure of lid. 6. The support shaft according to claim 1, wherein a corner portion of the support shaft that comes into contact with an inner surface of the tilt portion has a curved surface.
6. The locking structure for a lid for an underground structure according to any one of items 1 to 5.