JP4902869B2 - Manhole cover locking device - Google Patents

Description

  The present invention relates to a manhole cover locking device, which is used when locking the closed state of a manhole cover.

    As a conventional manhole cover locking device of this type, a locking device installed on the back side of the cover body is used for manholes by pressing the operation tool exposed on the surface of the cover against elasticity. The one to be released from the frame (Japanese Patent No. 3269888), and the operation tool exposed on the surface of the lid is rotated to swing the locking tool and locked to the manhole frame. There existed things which cancel a locked state (Unexamined-Japanese-Patent No. 11-158901).

Japanese Patent No. 3269888 JP-A-11-158901

    However, in such a conventional manhole cover locking device, in the former, since the locking tool can be opened by pickaxe or the like, the manhole cover can be opened, and as a result, it is easily opened illegally. Had inconvenience.

    An object of the present invention is to eliminate this inconvenience.

In order to achieve this object, in the manhole cover locking device according to the present invention, a rotating shaft is rotatably installed in the manhole cover so as to be substantially parallel to the axial direction of the manhole. A locking device for the manhole cover is installed, and the locking device can be slid from the rotating shaft portion toward the locking portion of the manhole frame so as to be locked to the locking portion. In the manhole cover locking device for locking the locking tool to the locking portion or releasing the locking by rotating the portion ,
An operation hole for inserting a tip of a work tool is formed in the manhole cover body, and a seal portion for sealing the operation hole by pressing from below the cover body is installed, and the work shaft is mounted on the rotating shaft section. A locking groove with the tip is formed, the tip of the working tool is inserted into the operation hole while pushing the seal portion, and is locked with the locking groove of the rotating shaft portion .

    In this case, the locking tool can be biased toward the locking portion.

    Further, in this manhole cover locking device, a slide hole is formed in the locking tool along the front-rear direction, and the spring support is installed over the rear end of the slide hole. A tension spring may be disposed between the spring support shaft of the tool and the rotary shaft portion, and the spring support shaft may be shifted from the position where the spring support tool is connected to the locking tool.

  In the manhole cover locking device, a cross-shaped locking groove may be formed on the upper end surface of the rotating shaft.

Since the manhole cover locking device according to the present invention is configured as described above, that is, the rotation shaft portion is rotatably installed in the manhole cover body so as to be substantially parallel to the axial direction thereof. The manhole cover locking device is installed at the same time, and the locking tool is slid from the rotating shaft portion toward the locking portion of the manhole frame so that it can be locked to the locking portion. In the manhole cover locking device for locking the locking tool to the locking portion or releasing the locking by rotating the rotating shaft portion ,
An operation hole for inserting a tip of a work tool is formed in the manhole cover body, and a seal portion for sealing the operation hole by pressing from below the cover body is installed, and the work shaft is mounted on the rotating shaft section. Since a locking groove with the tip is formed, the tip of the working tool is inserted into the operation hole while pushing the seal portion, and the locking groove of the rotating shaft portion is locked .
With the front end of the locking tool retracted, the manhole cover is closed to the manhole frame, and when the front end of the locking tool reaches the locking portion of the manhole frame, this is appropriately done by means. If the locking tool protrudes from the manhole cover and enters the locking portion, the closed state of the manhole cover is locked to the manhole frame. On the other hand, in order to release this locked state, if the rotating shaft portion is rotated in the locked state, the end of the locking tool is released from the locking portion of the manhole frame, and the manhole cover The locked state of the body is released.

    Therefore, with this manhole cover locking device, the lock state cannot be released by pickaxe or the like when locking the cover to the frame, so the manhole cover can be easily released. A locked state that cannot be configured can be configured by a simple operation.

    In this case, if the locking tool is urged in the direction of the locking portion, the manhole cover is closed to the manhole frame with the tip of the locking tool protruded. The tip of the tool retreats against elasticity while contacting the sloped inner wall surface of the manhole frame, and when it reaches the locking portion located below the sloped inner wall surface, It protrudes from the lid for the manhole and enters the locking portion, and the closed state of the lid for the manhole is locked to the frame for the manhole. In this state, if the rotating shaft portion is rotated, the locking tool swings, and the tip end portion thereof comes out of the locking portion of the manhole frame, and the locked state of the manhole cover is released. .

    Therefore, it is possible to lock the closed state only by performing the closing operation of the manhole cover, and the lock cannot be easily released by the pickaxe or the like. The state can be configured by a simple operation.

    Further, in this manhole cover locking device, a slide hole is formed in the locking tool along the front-rear direction, and the spring support is installed over the rear end of the slide hole. If a tension spring is disposed between the spring support shaft of the tool and the rotary shaft portion, and the spring support shaft is displaced from the position where the spring support tool is connected to the locking tool, the degree of this shift is adjusted. Thus, the elastic force of the tension spring can be easily adjusted.

    Further, in this manhole cover locking device, if a cross-shaped locking groove is formed on the upper end surface of the rotary shaft portion, a tip T-shaped working tool (the base and locking hooks are T-shaped). When the locking hook portion of the work tool integrally formed in the shape is inserted into the locking groove, the cross-shaped locking groove of the cross-shaped locking groove can be obtained even if the base hook portion is tilted obliquely around the locking hook portion. As a result of entering the remaining part (the part where the locking collar part is not inserted), the work tool does not collide with the rotating shaft part during the manhole cover opening work, and the work efficiency is improved. It is.

    A rotating shaft is rotatably installed on the manhole cover parallel to the axial direction. A locking tool is installed on the back side of the manhole cover of the rotating shaft. In the manhole cover locking device for locking the locking tool to the locking portion of the manhole frame or rotating the locking shaft by rotating the rotating shaft, the locking The tool needs to be slidable from the rotating shaft portion toward the locking portion of the manhole frame to be locked to the locking portion.

    Further, an operation hole for inserting a tip of a work tool is formed in the manhole cover body, a seal portion that is pressed from below the cover body to seal the operation hole is installed, and the work shaft is disposed on the rotating shaft section. It is necessary to form a locking groove with the tool tip, insert the tip of the working tool into the operation hole while pushing the seal part, and lock it with the locking groove of the rotating shaft part. is there

    Examples of the present invention will be described below.

1 is a side sectional view of a manhole cover locking device according to the present invention, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, FIG. 3 is a sectional view taken along the line III-III, and FIG. FIG. 5 is a cross-sectional view of the rotating shaft portion in FIG. 1, FIG. 6 is a view taken along the line VI in FIG. 5, and FIGS. 7 to 9 are diagrams showing steps for releasing the locked state. 7 is a view corresponding to FIG. 1, FIG. 8 is a view corresponding to FIG. 2, FIG. 9 is a view corresponding to FIG. 4, FIG. 10 is a plan view of the first embodiment of the stopper, and FIG. FIG. 12 is a view taken in the direction of arrow XI in FIG. 10, FIG. 12 is a view taken in the direction of arrow XII in FIG. 11, FIG. 13 is a plan view of the state where the rotation axis rotates clockwise and the stopper functions, and FIG. FIG. 15 is a plan view of the second embodiment of the stopper, FIG. 16 is a view from the XVI arrow in FIG. 15, and FIG. 17 is a view from the XVII arrow in FIG. Figure 18 is a plan view of a state in which the rotation shaft rotates clockwise and the stopper functions, FIG. 19 is a plan view of a state in which the rotation shaft rotates counterclockwise and the stopper functions, and FIG. 21 is a plan view of the third embodiment, FIG. 21 is a view taken in the direction of arrow XXI in FIG. 20, FIG. 22 is a view taken in the direction of arrow XXII in FIG. 21, and FIG. FIG. 24 is a plan view showing a state in which the rotation shaft rotates counterclockwise and the stopper functions. FIG. 25 is a view corresponding to FIG. 1 in the second embodiment of the manhole cover locking device according to the present invention. FIG. 26 is a diagram corresponding to FIG. 1 in the third embodiment, and FIG. 27 is a diagram corresponding to FIG. 1 in the fourth embodiment.

    1 to 3, M is a manhole cover, which is composed of a manhole frame (hereinafter referred to as “frame”) 10 and a manhole cover (hereinafter referred to as “lid”) 20. The frame 10 is fixed to a manhole or an underground structure by a plurality of anchor bolts 11,. The frame 10 has a circular opening. The inner peripheral surface of the entrance of this opening is formed in a taper shape. The same effect (automatic locking of the lid 20) can be obtained by tapering the bottom surface of the locking claw 65, which will be described later, instead of forming the inner peripheral surface of the inlet at the opening in a tapered shape. Reference numeral 12 denotes a locking recess (corresponding to the “locking portion” of the present invention), which is formed in a half-moon shape (in plan view) below the inner peripheral wall surface of the frame body 10. A locking claw 65, which will be described later, enters the locking recess 12.

    Next, the lid 20 is fitted in the opening of the frame 10 so as to be opened and closed. Reference numeral 21 denotes an operation hole, which is formed on the peripheral edge of the lid 20. The operation hole 21 has a long hole shape, and its axis extends in parallel with the axis of the opening of the frame body 10. Reference numeral 22 denotes a support shelf, which is integrally formed on the back side of the lid 20. The support shelf 22 is positioned substantially below the operation hole 21. Reference numeral 23 denotes a curved support portion, which is formed on the support shelf 22. The curved support portion 23 is curved in a substantially U shape from the rear end side (right side in FIG. 1) of the support shelf 22.

    R is a rotation shaft portion, and is latched to the curved support portion 23 of the support shelf 22 in the lid body 20. Reference numeral 30 denotes a rotating cylinder, which constitutes a main part of the rotating shaft portion R. Reference numeral 31 denotes an outward flange, which is integrally formed with the upper end edge of the rotary cylinder 30. The rotating shaft portion R is hooked on the curved support portion 23 through the outward flange 31. At this time, since the step is provided in the curved support portion 23, the outward flange 31 is fitted, and the rotating shaft portion R can endure swinging.

    Reference numerals 32 and 32 denote a pair of support plates, which are integrally formed on the upper end edge of the rotary cylinder 30. The pair of support plates 32 and 32 are arranged via a predetermined space and extend upward (see FIGS. 5 and 6). 33 and 33 are marginal spaces, and are formed in a U-shape at the upper edges of the support plates 32 and 32. The marginal spaces 33, 33 and the pair of support plates 32, 32 constitute a “cross-shaped locking groove” according to the present invention by a predetermined space.

    Reference numerals 34 and 34 denote a pair of guide portions, which protrude from the outer wall surfaces on both sides of the rotary cylinder 30. The pair of guide portions 34, 34 extend horizontally. The functions of the guide portions 34, 34 will be described later. A spring seat 35 projects from the outer wall surface on the rear side (right side in FIG. 1) of the rotary cylinder 30. One end of a tension spring 36 is hooked on the spring seat 35.

    An operation shaft 50 is fitted in the rotary cylinder 30 so as to be able to advance and retract. Reference numeral 51 denotes a seal portion, which is integrally formed on the top portion of the operation shaft 50. The seal portion 51 has a rectangular shape, and advances and retreats in the space between the pair of support plates 32 and 32 with the short side sandwiched (see FIG. 6). A compression spring 52 is stretched between the bottom portion of the rotating cylinder 30 and the seal portion 51 of the operation shaft 50 in a state of being externally fitted to the operation shaft 50. The compression spring 52 urges the operation shaft 50 upward and presses the seal portion 51 against the operation hole 21 of the lid body 20. By the compression spring 52, the outward flange (of the rotary cylinder 30) 31 and the seal portion 51 (of the operation shaft 50) are repelled in opposite directions, and the outward flange 31 is pressed against the back surface of the lid body 20. The operation hole 21 of the lid 20 is sealed, and the rotating cylinder 30 is assembled and fixed to the support shelf 22 of the lid 20. Since this assembly does not require the use of bolts or the like, it can be achieved by a simple operation.

    Reference numeral 53 denotes a locking projection that protrudes from the surface of the seal portion 51. The locking projection 53 has a rectangular shape, elastically enters the operation hole 21 of the lid 20 and locks the rotation of the operation shaft 50, and escapes and locks against the elasticity. To release. It is necessary to make the gap between the position when the locking projection 53 is pressed and the back surface of the lid 20 as narrow as possible. This further presses the seal portion 51 (of the operation shaft 50) against the back surface of the lid body 20 by the compression spring 52, and completes the sealing performance of the operation hole 21 of the lid body 20. Because.

    Returning to FIGS. 1 to 4, the embodiment will be described.

    Reference numeral 60 denotes a disk-shaped locking tool, which is installed outside the rotating cylinder 30. The locking tool 60 is a part that moves forward and backward to lock the frame body 10 and release the locking. Reference numeral 61 denotes a slide hole, which is formed in the locking tool 60. The rear end (right side in FIG. 1) of the slide hole 61 is open. Reference numerals 62 and 62 denote guide grooves, which are formed on the inner wall surface of the slide hole 61. The guide grooves 62, 62 extend along the front-rear direction along the locking direction of the locking tool 60. A pair of guide portions 34, 34 in the rotary cylinder 30 are fitted into the guide grooves 62, 62 so as to be able to advance and retreat. For this reason, the locking tool 60 can advance and retreat in the front-rear direction along the locking direction while being supported by the rotary cylinder 30.

  Reference numeral 63 denotes a spring support, which is bolted to the rear end portion of the locking tool 60. The root portion of the spring support 63 closes the rear end edges of the guide grooves 62 and 62. Further, it is formed in a substantially U shape, and has a spring support shaft 64 in the middle part thereof. The other end of the tension spring 36 is hooked on the spring support shaft 64. For this reason, as a result of the locking tool 60 being pulled in relation to the rotary cylinder 30, normally, the locking tool 60 is elastically advanced in the forward direction. The root portion of the spring support 63 prevents the guide grooves (of the holder 60) 62, 62 from falling off the guide portions (of the rotating cylinder 30) 34, 34.

Next, reference numeral 65 denotes a locking claw, which protrudes from the leading edge of the locking tool 60. The locking claw 65 elastically enters the locking recess 12 of the frame 10 by the elastic force of the tension spring 36 and locks the closed state of the lid 20. Reference numerals 66 and 66 denote cover plates, which are integrally formed on both sides of the locking claw 65 at the leading edge of the locking tool 60. The cover plates 66, 66 are formed so that the leading edges thereof are curved , and when the lid 20 is fitted into the frame 10, the portion of the locking member 60 does not bite the inner peripheral edge of the lid 10. To be able to move backwards smoothly.

  When the lid body 20 including the lid body locking device configured as described above is installed in the frame body 10, the locking claw (of the locking tool 60) 65 is connected to the locking recess (the frame body). The lid 20 is positioned so as to coincide with 12), and the locking tool 60 can be inserted through the opening of the frame 10 as it is. Then, the locking claw 65 in the locking tool 60 retracts while entering along the tapered surface of the entrance of the opening, and when the locking claw 65 reaches the locking recess (of the frame body 10) 12, it is elastically again. Advances and enters the locking recess (of the frame 10) 12 (in this case, instead of forming the inner peripheral surface of the inlet in the opening in a tapered shape, the bottom surface of the locking claw 65 is tapered later. However, the same effect can be obtained). For this reason, the closed state can be locked simultaneously with the closing operation of the lid 20.

Further, when releasing the closed lock of the lid 20, as shown in FIGS. 7 and 8,
The locking hook 72 of the tip T-shaped working tool (working tool in which the base hook 71 and the locking hook 72 are integrally formed in a T-shape) 70 enters the operation hole 21 of the lid 20. Then, the locking projection (of the operation shaft 50) 53 is pushed out of the operation hole 21 against elasticity (the state shown in FIGS. 7 and 8).

  In this state, when the operation shaft 50 is rotated 90 ° as shown in FIG. 9, the locking claw 65 of the locking tool 60 is disengaged from the locking recess 12 of the frame body 10 (FIG. 4). (See the state), the lock of the lid 20 in the closed state is released, and the locking bar 72 of the work tool 70 is hooked on the operation hole 21 of the lid 20. In this state, the lid 20 can be released from the frame 10 by pulling up the work tool 70. At this time, since the base part 71 of the work tool 70 pulls the lid 20 from the standing position of the operator, even if the base part 71 swings around the locking hook part 72, the marginal space of the support plates 32, 32 In order to enter 33,33, the locking collar portion 72 does not interfere with the operation hole 21 ahead, and does not enter the marginal spaces 33,33. Therefore, the support plates 32 and 32 do not collide, and as a result, the work is easy. In the case where the work tool 70 is extracted from the operation hole 21 with the lid 20 opened, the operation shaft 50 may be rotated reversely by 90 ° so as to be in the state of FIGS. At this time, the locking claw 65 of the locking tool 60 is in a state of elastically protruding from the frame body 10, and the lid body 20 can be installed on the frame body 10. Moreover, you may provide the stoppers 81 and 82 as shown to FIGS. 10-24 so that it may not rotate 90 degree or more on operation.

    At this time, since the operating shaft 50 protrudes downward from the rotating cylinder 30, in order to prevent the protruding portion from coming into contact with the road surface or the like and being difficult to rotate, temporary wire shown in FIGS. As shown in FIG. 7, the rotating cylinder 30 may be extended downward to cover the protruding portion, or as shown in FIG. It is also possible to provide a baffle member (bar-like or plate-like) 90 that extends further forward than the protruding portion to prevent the protruding portion from contacting the road surface or the like.

  10 to 14 show a first embodiment of the stopper 81, 82 mechanism. In this embodiment, the stoppers 81 and 82 are respectively installed at different heights on both sides of the rotating shaft portion R in the support shelf 22 (see FIGS. 10 and 12). Reference numerals 86 and 87 denote collision protrusions, which are installed at different heights one by one at the front ends (end edges in the locking direction) of the pair of support plates 32 and 32 in the rotating shaft R (see FIG. (See 10, 11, 12). Then, when the rotary shaft R is rotated 90 ° clockwise from the state of FIG. 10, the locking projection 86 collides with the stopper 81 to stop this rotation (state of FIG. 13). When the rotating shaft R rotates 90 ° counterclockwise, the locking projection 87 collides with the stopper 82 to stop the rotation (state shown in FIG. 14).

  15 to 19 show a second embodiment of the stopper 81, 82 mechanism. In this embodiment, the stoppers 81 and 82 are respectively installed at the same height on both sides of the rotating shaft portion R in the support shelf 22 (see FIGS. 15 and 17). Reference numerals 86 and 87 denote collision projections, which are respectively installed at the same height at the front ends (end edges in the locking direction) of the pair of support plates 32 and 32 in the rotating shaft R (FIG. 15). , 16, 17). Then, when the rotary shaft R rotates 90 ° clockwise from the state of FIG. 15, the locking projection 86 collides with the stopper 81 to stop this rotation (state of FIG. 18), When the rotation shaft portion R rotates 90 ° counterclockwise, the locking projection 87 collides with the stopper 82 and stops this rotation (state shown in FIG. 19).

  20 to 24 show a third embodiment of the stopper 81, 82 mechanism. In this embodiment, the stoppers 81 and 82 are respectively installed at different heights on both sides of the rotating shaft portion R in the support shelf 22 (see FIGS. 20 and 22). Reference numerals 86 and 87 denote collision protrusions, which are respectively installed at different heights on the front end sides (end edges in the locking direction) of the side surfaces of the pair of support plates 32 and 32 in the rotating shaft R. (See Figures 20, 21, and 22). Then, when the rotary shaft portion R rotates 90 ° clockwise from the state of FIG. 20, the locking projection 86 collides with the stopper 81 to stop this rotation (state of FIG. 23). When the rotary shaft R rotates 90 ° counterclockwise, the locking projection 87 collides with the stopper 82 and stops this rotation (state shown in FIG. 24).

  FIG. 25 shows a second embodiment of the manhole cover locking device according to the present invention, in which the operation hole 21 is formed at the edge of the cover 20. In this case, it is necessary to install the operation shaft 50 in parallel with the tapered surface of the frame 10 in order to enable the rotation shaft portion R to rotate and to ensure the sealing performance of the seal portion 51. Therefore, it is necessary to install the horizontal portion of the support shelf 22 so as to be inclined downward toward the outer side (radial direction of the lid 20).

    Next, FIG. 26 shows a third embodiment of a manhole cover locking device according to the present invention. In this case, the rear end portion of the locking member 60 is connected to the lower end of the rotary shaft portion R through the shaft 89 so as to be swingable by clevis connection. And it always installs so that the front end side may incline downward by its own weight. For this reason, the lid 20 is positioned so that the locking claw 65 (of the locking tool 60) is aligned with the locking recess (of the frame 10) 12, and the opening of the frame 10 is left as it is. The locking tool 60 may be inserted from the inside. Then, the locking claw 65 in the locking tool 60 swings upward while entering along the tapered surface of the entrance of the opening, and when it reaches the locking recess (of the frame body 10) 12, It swings downward by its own weight and enters the locking recess (of the frame 10) 12. For this reason, the closed state can be locked simultaneously with the closing operation of the lid 20. In order to cancel, the same operation as that of the first embodiment of the manhole cover locking device may be performed.

     Next, FIG. 27 shows a fourth embodiment of a manhole cover locking device according to the present invention. In this case, instead of using the dead weight of the locking tool 60 in the third embodiment, a spring 88 can be installed and urged so that the front end side of the locking tool 60 tilts downward.

    Only by performing the manhole cover closing operation, the closed state can be locked, and depending on the pickaxe or the like, this locked state cannot be released, so as a locking device for the manhole cover closed state, It can be used to improve the efficiency of the lid closing operation and to prevent the lid from being opened without permission.

FIG. 1 is a side sectional view of a manhole cover locking device according to the present invention. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a sectional view taken along line III-III. FIG. 4 is a view corresponding to FIG. 3 in a state in which the locking tool is released. FIG. 5 is a cross-sectional view of the rotating shaft portion in FIG. FIG. 6 is a view taken along arrow VI in FIG. FIG. 7 is a diagram illustrating a process of releasing the locked state of the lid closed, and corresponds to FIG. 8 is a diagram showing a process of releasing the lock state, corresponding to FIG. FIG. 9 is a view showing a process of releasing the lock state, and corresponds to FIG. FIG. 10 is a plan view of the first embodiment of the stopper. FIG. 11 is a view taken along arrow X1 in FIG. 12 is a view taken along arrow XII in FIG. FIG. 13 is a plan view showing a state where the rotation shaft rotates clockwise and the stopper functions. FIG. 14 is a plan view showing a state in which the rotation axis rotates counterclockwise and the stopper functions. FIG. 15 is a plan view of a second embodiment of the stopper. FIG. 16 is an XVI arrow view in FIG. FIG. 17 is a view taken along arrow XVII in FIG. FIG. 18 is a plan view showing a state where the rotation shaft rotates clockwise and the stopper functions. FIG. 19 is a plan view showing a state where the rotation axis rotates counterclockwise and the stopper functions. FIG. 20 is a plan view of a third embodiment of the stopper. FIG. 21 is a view taken along arrow XXI in FIG. 22 is a view taken in the direction of arrow XXII in FIG. FIG. 23 is a plan view showing a state where the rotation shaft rotates clockwise and the stopper functions. FIG. 24 is a plan view showing a state where the rotation axis rotates counterclockwise and the stopper functions. FIG. 25 is a view corresponding to FIG. 1 in the second embodiment of the manhole cover locking device according to the present invention. FIG. 26 is a view corresponding to FIG. 1 in the third embodiment. FIG. 27 is a view corresponding to FIG. 1 in the fourth embodiment.

M ... Manhole cover
10… Manhole frame (frame)
11… Anchor bolt
12… Locking recess (locking part)
20… Manhole cover (lid)
21… Operation hole
22… Support shelf
23… Curved support part R… Rotating shaft part
30… Rotating cylinder
31… outward flange
32… Support plate
33… Extra space (cross-shaped locking groove)
34… Guide section
35… Spring seat
36… tension spring
50… Operation axis
51… Seal part
52… Compression spring
53… Locking protrusion
60… Locking device
61… Slide hole
62… Guide groove
63… Spring support
64… Spring support shaft
65… Claw
66… Cover plate
70… Work implement
71… Basic part
72… Locking collar
81… Stopper
82… Stopper
86… Collision protrusion
87… Collision protrusion
88… Spring
89… axis

Claims (4)

A rotating shaft portion is rotatably installed on the manhole cover body so as to be substantially parallel to the axial direction of the manhole cover. A locking device for the manhole cover body is installed on the rotating shaft portion, and the locking tool is attached to the rotating shaft portion. From the slide to the locking portion of the manhole frame, the locking portion can be locked to the locking portion. By rotating the rotating shaft portion, the locking tool can be locked to the locking portion. In the manhole cover locking device for releasing this locking,
An operation hole for inserting a tip of a work tool is formed in the manhole cover body, and a seal portion for sealing the operation hole by pressing from below the cover body is installed, and the work shaft is mounted on the rotating shaft section. A manhole cover , wherein a locking groove with a tip is formed, the tip of the working tool is inserted into the operation hole while the seal portion is pushed in, and locked in the locking groove of the rotating shaft portion Locking device. 2. The manhole cover locking device according to claim 1, wherein the locking member is urged toward the locking portion. 3. The manhole cover locking device according to claim 2, wherein a slide hole is formed in the locking tool along the front-rear direction, and a spring support is hung over the rear end of the slide hole. A manhole characterized in that a tension spring is disposed between a spring support shaft of a support tool and the rotary shaft portion, and the spring support shaft is displaced from a position where the spring support tool is connected to the locking tool. Lid lock device. 3. The manhole cover locking device according to claim 2, wherein a cross-shaped locking groove is formed on an upper end surface of the rotating shaft portion.

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