JP2001254539A - Keyhole closing device for manhole cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a keyhole closing device for a manhole cover, by which extraction from a keyhole for the manhole cover can be conducted surely. SOLUTION: The keyhole closing device 11 has a drum section 12 inserted into the keyhole 3 formed to the manhole cover 1 and a cover section 13 screwed to the drum section 12. A locking mechanism section 21 and a control unit section 51 are disposed into the keyhole closing device 11. The locking mechanism section 21 has a lock pin 22, a rocking shaft 23, a gear 24, a step-up gear row 31 and an electromagnetic solenoid. The lock pin 22 is disposed to a recessed section 14 formed to the drum section 12, and fixed onto the rocking shaft 23 axially supported to the drum section 12 through bearing sections 25, 25. The gear 24 formed in a fan shape is fixed at the end section of the rocking shaft 23. The step-up gear row 31 speeds up the rocking of the gear 24, and transmits the speed-up to the fourth gear pair 35. A pin 36 capable of being engaged with a rod for the electromagnetic solenoid is projected from the fourth gear pair 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a keyhole closing device for a manhole cover for closing a keyhole formed in a manhole cover.

[0002]

2. Description of the Related Art A keyhole closing device for a manhole cover of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-205184. This Japanese Patent Laid-Open No. 10-2
The keyhole closing device for a manhole cover disclosed in Japanese Patent No. 05184 is composed of a main body, a main shaft, and a tightening nut. A cylindrical outer peripheral surface portion is provided at a lower portion of the main body inserted into the keyhole of the manhole cover, and a diametrical groove is formed on the outer peripheral surface portion. An upper end of the main shaft is provided with a passive end to which the driving end of the operating handle is disengaged, and a lower flange is provided below the passive end. On the lower side of the retaining flange, a male screw rod is provided. The tightening nut is screwed to the male screw rod of the main shaft, and a fixing claw is formed on the upper part of the tightening nut, which passes through the relief hole connected to the keyhole and comes into contact with and separates from the lower surface of the manhole cover. ing.
Further, on the opposing groove wall surfaces of the split groove, there are provided a forward rotation regulating surface on which the fixing claw abuts during forward rotation of the main shaft and a reverse rotation regulating surface on which the fixing claw abuts upon reverse rotation of the main shaft. ing. The tightening nut rotates integrally with the main shaft when rotating between the forward rotation regulating surface and the reverse rotation regulating surface, and moves linearly in the vertical direction along the main shaft after coming into contact with each regulating surface.

[0003] Japanese Patent Laid-Open Publication No.
In the keyhole closing device for a manhole cover disclosed in Japanese Patent Publication No. 4 (1999) -1995, when the driving end of the operation handle is fitted to the passive end of the main shaft and the main shaft is rotated by a predetermined angle in the forward direction, the fixing claw is It separates from the regulating surface during reverse rotation and contacts the regulating surface during forward rotation of the split groove. If the main shaft continues to rotate forward even after the fixing claw abuts on the regulating surface during forward rotation, the tightening nut linearly moves upward along the main shaft and approaches the lower surface of the manhole cover. Thus, by the engagement of the fixing claw with the edge of the lower hole of the keyhole, the main body is fixed so that it cannot be removed from the keyhole, and the keyhole of the manhole cover is closed.

Further, the drive end of the operation handle is fitted to the passive end of the main shaft to rotate the main shaft in a reverse direction by a predetermined angle. Thereby, the fixing claw is detached from the regulating surface at the time of forward rotation, and comes into contact with the regulating surface at the time of reverse rotation. If the reverse rotation of the main shaft is continued even after the fixing claw abuts on the restriction surface at the time of reverse rotation, the tightening nut moves linearly downward along the main shaft. In this state, since the fixing claw is located at a position facing the escape hole, the main body is pulled out from the keyhole of the manhole cover when the fixing claw passes through the escape hole.

[0005]

However, in the keyhole closing device for a manhole cover having the above-described structure, components such as the main body, the main shaft (male screw bar) and the tightening nut are exposed to the humid environment in the manhole. Therefore, there is a concern that rust or the like may be generated on these components, or that dirt or the like may adhere to the components, such that a plurality of components, for example, the main shaft (male screw rod) and the tightening nut may be fixed. When the main shaft (male screw bar) and the tightening nut are thus fixed, it becomes difficult to remove the main body from the keyhole of the manhole cover.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a manhole cover keyhole closing device capable of reliably removing a manhole cover from a keyhole.

[0007]

SUMMARY OF THE INVENTION A keyhole closing device for a manhole cover according to the present invention is a keyhole closing device for a manhole cover which is inserted into a keyhole formed in the manhole cover to close the keyhole. The torso portion is rotatably supported with respect to the torso portion, and at the first swinging position, a part thereof projects from the outer periphery of the torso portion so as to be engaged with the manhole cover. In the second swing position, when the lock pin is in a state in which the engagement state with the manhole cover is released, and when the lock pin swings to the first swing position,
A lock pin swing inhibiting means for inhibiting the swing of the lock pin, wherein the lock pin comes into contact with the manhole cover when the body is pulled out of the keyhole, and the first swing position. From the first to the second swing position.

The keyhole closing device for a manhole cover according to the present invention has a body, a lock pin, and a lock pin swing inhibiting means, and the lock pin swings to a first swing position.
When a part of the lock pin protrudes from the outer periphery of the body and is in a state in which the lock pin can be engaged with the manhole cover, the rock pin is prevented from swinging by the lock pin swing inhibiting means. The lock pin and the manhole cover will engage when the is pulled out from the keyhole. This can prevent the keyhole closing device from being removed.

Further, when the lock pin rocking device is pulled out of the keyhole by an operator or the like in a case where the lock pin rocking prohibiting means is released from the state in which rocking of the lock pin is prohibited by the lock pin rocking prohibiting means, the lock pin is moved to the manhole cover. In contact therewith, it swings from the first swing position toward the second swing position, and the state in which it can be engaged with the manhole cover is released. Thereby, the keyhole closing device can be extracted from the keyhole. Furthermore, since the force by which the worker lifts the keyhole closing device directly acts on the lock pin due to the contact between the lock pin and the manhole cover, an extremely large force is applied to the lock pin. Acts in the direction in which the lock pin is swung, so that even if rust, dirt, etc. adhere to the lock pin, the lock pin can be swung reliably, and the lock pin closing device can be removed from the key hole. It can be done reliably.

It is preferable that the apparatus further comprises a lock pin swinging means for swinging the lock pin so that the first swing position is in the initial state of the lock pin. In the case of such a configuration, first, by inserting the lock pin from the initial state (the first swing position) to the second swing position, the torso (keyhole closing device) can be inserted into the keyhole. It is possible. When the insertion of the body into the keyhole is completed, the lock pin swinging means swings the lock pin to bring the lock pin into the initial state (the first swing position). Can be engaged. Therefore, by having the lock pin swinging means, it is possible to easily shift to a state where the lock pin and the manhole cover can be engaged when the body is completely inserted into the keyhole.

[0011] The gear further includes a gear that rotates integrally with the lock pin, and a speed increasing gear train that meshes with the gear to increase the rotation of the gear. Preferably, the lock pin swing inhibiting means includes solenoid means for engaging the pin to stop rotation of the terminal gear pair. In such a configuration, the lock means is prevented from swinging by engaging the solenoid means with the pin protruding from the gear pair at the end of the speed increasing gear train, so that the keyhole closing device must be removed. Can be prevented. Also, the solenoid means is engaged with the pin,
If the keyhole closing device is forcibly pulled out in a state where the rocking pin is prohibited from swinging, an extremely large force acts in the direction of swinging the lockpin, but it rotates together with the lockpin. Since power is transmitted between the gear and the terminal gear pair at which the pin is protruded by the speed increasing gear train, an extremely large force acting on the lock pin is reduced and acts on the solenoid means. become. As a result, damage to the pins, the solenoid means, and the like can be prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a keyhole closing device for a manhole cover according to the present invention will be described below in detail with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

(First Embodiment) FIG. 1 is a perspective view for explaining a configuration of a keyhole closing device for a manhole cover according to a first embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view showing a configuration of the keyhole closing device for the manhole cover, FIG. 3 is a cross-sectional view taken along a line III-III in FIG. 2, and FIG. 4 is a cross-sectional view taken along a IV-IV line in FIG. FIG.

The manhole cover 1 is provided in a manhole serving as an opening through an underground object, an underground structural facility, and the ground, and is supported by a cover receiving frame 2 buried in the ground surface of the ground. . As the manhole cover 1,
For large-scale iron lids, sewage basins lids that can open and close underground buried objects in sewers, underground structural facilities, etc., and the opening through the ground, and openable joint grooves that protect underground facilities equipment and wiring in power and communications Iron lid, power transmission iron lid, power distribution iron lid,
A fire hydrant lid, a water control valve lid, a partition valve lid, an air valve lid, a gas pipe lid, which has a function as an opening / closing door connecting the buried conduit under the road surface and its attached equipment and the ground to the water supply and gas pipes,
It is applicable as a water meter lid or the like.

The manhole cover 1 is provided with a locking mechanism, not shown, to prevent the manhole cover 1 from being easily opened. The locking mechanism is operated / locked / unlocked by a tool inserted through a keyhole 3 formed in the manhole cover 1, for example, a T-shaped tip portion of a bar-shaped hand key. As shown in FIG. 1, a keyhole closing device 11 is inserted into the keyhole 3 of the manhole cover 1 to close the keyhole 3 and prevent the manhole cover 1 from being opened by mischief or the like. . The keyhole closing device 11 has a lock mechanism 21 and a control unit 51 inside.

As shown in FIG. 2, the keyhole closing device 11 has a body 12 inserted into the keyhole 3 formed in the manhole cover 1 and a cover 13 screwed to the body 12. are doing. The body 12 has a cup shape with an open upper surface, and the upper surface opening is covered with a lid 13. Between the lid 13 and the trunk 12, rainwater into the trunk 12,
An O-ring or the like (not shown) is provided to prevent intrusion of dust, dirt, and the like. As shown in FIGS. 2 and 3, a concave portion 14 is formed in the body portion 12. Torso 12
The lock mechanism 21 and the control unit 51 described above are provided in an internal space defined by the cover 13 and the cover 13. The lid 13 or the body 12 has a keyhole closing device 11 attached thereto.
It is preferable to provide a clue for pulling out with a special tool. In addition, the cover 13 is provided with a keyhole 3 so as to prevent attachments such as mud and dust from adhering to a gap formed between the keyhole closing device 11 (the body 12 or the cover 13) and the keyhole 3.
May be formed so as to cover from above.

Next, the configuration of the lock mechanism 21 will be described. The lock mechanism 21 includes a lock pin 22, a swing shaft 23, a gear 24, a speed increasing gear train 31, an electromagnetic solenoid 41, and the like, as shown in FIGS. The lock pin 22 is provided with the concave portion 14
And a pair of wall portions 1 forming the concave portion 14
5 and 15 are fixed to a swing shaft 23 that is supported by bearings 25 and 25 via bearings 25 and 25, and are configured to be swingable with respect to the body 12. The bearing portions 25, 25 are filled with grease or the like. A fan-shaped gear 24 is fixed to one end of the swing shaft 23, and the gear 24 swings integrally with the swing shaft 23.

The lock pin 22 is moved to a first swing position (FIG. 2).
To the position shown by the solid line).
A part of 2 protrudes from the outer periphery (recess 14) of body 12 and is in a state capable of engaging with manhole cover 1. When the lock pin 22 swings to the second swinging position (the position shown by the one-dot chain line in FIG. 2), the lock pin 22 is almost entirely housed in the concave portion 14 of the body portion 12 and can be engaged with the manhole cover 1. Is released.

At the other end of the swing shaft 23, a torsion spring 26 for applying a biasing force to the swing shaft 23 in the direction in which the lock pin 22 swings to the first swing position is provided. I have. Due to the urging force of the torsion spring 26, the lock pin 22 swings so that the initial position becomes the first swing position. Here, the torsion spring 26 constitutes a lock pin swing means in each claim. Instead of providing the torsion spring 26, a tension spring is applied to the gear 24 so that the lock pin 2
2 may be configured to apply an urging force to the swing shaft 23 (lock pin 22) in a direction in which the swing shaft 2 swings to the first swing position.

The speed increasing gear train 31 includes a first gear pair 32,
It is composed of a second gear pair 33, a third gear pair 34, and a fourth gear pair 35, and the speed of the oscillation of the gear 24 is increased and transmitted to the fourth gear pair 35. The first gear pair 32 has a pinion 32a meshing with the gear 24 and a large-diameter gear 32b, and is supported by a bearing (not shown). The second gear pair 33 includes a pinion 33a that meshes with the large diameter gear 32b of the first gear pair 32, and a large diameter gear 33b. Like the first gear pair 32, a bearing (not shown) Part. The third gear pair 34 includes a pinion 34a that meshes with the large-diameter gear 33b of the second gear pair 33, and a large-diameter gear 3
4b, and like the first gear pair 32 and the second gear pair 33, are supported by a bearing (not shown). 4th
Has a pinion 35a meshing with the large-diameter gear 34b of the third gear pair 34, and a large-diameter gear 35b, and is similar to the first to third gear pairs 32, 33, and 34. To
It is supported by a bearing (not shown). Two pins 36, 36 protrude from the surface of the large-diameter gear 35b of the fourth gear pair 35 opposite to the surface on the pinion 35a side. here,
The fourth gear pair 35 constitutes the last gear pair in each claim. The number of gear pairs of the speed increasing gear train 31 and the diameter of each gear pair 32-35 (pinions 32a-35a or large-diameter gears 32b-35b) are not limited to those shown, but can be set as appropriate. is there.

The electromagnetic solenoid 41 is connected to the control unit 5
The excited state and the non-excited state are controlled based on the control signal output from 1. The electromagnetic solenoid 41 has a rod 42 which can be engaged with the pin 36.
Is set to a protruding position when the electromagnetic solenoid 41 is not excited, and engages with the pin 36 as shown in FIGS. Rod 42 and pin 36 of electromagnetic solenoid 41
Are engaged, each gear pair 32 to 35 of the speed increasing gear train 31
Is restricted, and the swing of the gear 24, that is, the lock pin 22, is prohibited. The rod 42
Is set to the retracted position when the electromagnetic solenoid 41 is excited, and the engagement with the pin 36 is released. When the engagement relationship between the rod 42 of the electromagnetic solenoid 41 and the pin 36 is released, each gear pair 32 to 35 of the speed increasing gear train 31 becomes rotatable, and the gear 24, that is, the lock pin 22 can swing. Becomes Here, the electromagnetic solenoid 41 constitutes a lock pin swing prohibition unit in each claim.

As shown in FIG. 5, the control unit 51 includes a semiconductor chip 52 integrally packaged, such as an IC (semiconductor integrated circuit) chip or an LSI (large-scale integrated circuit) chip, and a coil. Shaped antenna 53
It has a transmitter / receiver 53 having a and the like, a power storage unit 54 composed of a capacitor and the like, and an electromagnetic solenoid drive circuit 55, which are covered with a mold or the like.

The CPU 52 is provided inside the semiconductor chip 52.
a, a ROM 52b and a RAM 52c are provided.
The PU 52a receives a signal including ID information such as a password and a code transmitted from the external terminal 61, and receives and transmits the power transmitted from the terminal 61. Is connected. The CPU 52a is a central processing unit,
Reads programs and various data from the ROM 52b,
It performs necessary calculations and performs various controls. Also,
ID information such as a password and a code included in the signal transmitted by the worker using the terminal 61 is received and temporarily stored in the RAM 52c, and this ID information and the ID information for verification stored in the ROM 52b in advance. Is compared with.

The ROM 52b is a read-only memory serving as a storage unit. The ROM 52b is used to verify various programs for operating the CPU 52a and ID information such as a password and a code included in a signal transmitted from the external terminal 61. Stores various necessary data. Also, in the ROM 52b,
The result of the authentication identification by collating the ID information such as the password and the encryption included in the signal transmitted from the terminal 61 is transmitted to the terminal 61.
, And management data such as various piping diagrams and wiring diagrams buried and housed in roads and their management-related facilities and road-occupied properties are stored.

The RAM 53c is a random access memory that serves as a storage unit. The RAM 52c is a working area where the CPU 52a temporarily stores the data in the instruction and the operation result, and the password included in the signal transmitted from the external terminal 61. And a buffer area for storing various data such as ID information such as ID and encryption.

The power storage unit 54 serving as a power storage means receives the power of the semiconductor chip 52 and the electromagnetic solenoid 41 from the outside in a non-contact manner and temporarily stores the power.
, Power received by the electromagnetic induction action via the transceiver 53 is stored by a capacitor or the like.

The electromagnetic solenoid drive circuit 55 includes a CPU 5
2a, and controls power supplied to the electromagnetic solenoid 41 based on a control signal output from the CPU 52a such that the electromagnetic solenoid 41 is in an excited state or a non-excited state. The electromagnetic solenoid drive circuit 55
Is connected to the power storage unit 54, the power stored in the power storage unit 54 is transmitted to the electromagnetic solenoid drive circuit 55, and the power transmitted from the power storage unit 54 is used as power supplied to the electromagnetic solenoid 41.

External terminal 61 operated by an operator
Has a display 62 and an input key 63 for inputting ID information such as a personal identification number and encryption. As shown in FIG. 1, the external terminal 61 transmits a signal including ID information such as a personal identification number and a code input by the input key 63 to the control unit 51. At this time, I
Power is also transmitted simultaneously with the signal including the D information.

Next, the operation of the keyhole closing device 11 configured as described above will be described with reference to FIGS. 2 to 4, FIG. 6, and FIG.

When the keyhole closing device 11 is inserted into the keyhole 3, the operator first sends a signal from the external terminal 61 to the control unit 51, and the CPU 52a sends a control signal so that the electromagnetic solenoid 41 is excited. Is output to the electromagnetic solenoid drive circuit 55. When the electromagnetic solenoid 41 is in the excited state, as described above, since the lock pin 22 can swing, the operator can
By swinging 2 to the second swing position, the keyhole closing device 11 can be easily inserted into the keyhole 3 of the manhole cover 1 as shown in FIG.

When the insertion of the keyhole closing device 11 is completed, the lock pin 22 swings to the first swing position under the urging force of the torsion spring 26 as shown by the solid line in FIG. , And can be engaged with the manhole cover 1. In this state, the worker sends a signal from the external terminal 61 to the control unit 51, and the CPU 5
From 2a, a control signal is output to the electromagnetic solenoid drive circuit 55 so that the electromagnetic solenoid 41 is de-energized.
When the electromagnetic solenoid 41 is de-energized, the pin 36 of the fourth gear pair 35 and the rod 42 of the electromagnetic solenoid 41 engage as shown in FIGS. The rotation of each gear pair 32 to 35 is regulated, and the swing of the lock pin 22 is prohibited. Thus, when someone tries to pull out the keyhole closing device 11 from the keyhole 3, the lock pin 22 and the manhole cover 1 are engaged, so that the keyhole closing device 11 can be prevented from being removed.

In the keyhole closing device 11 having the above-described configuration, as described above, the torsion spring 26 is provided, and the lock pin 22 receives the urging force of the torsion spring 26 to reach the first swing position. Swings and becomes in a state where it can be engaged with the manhole cover 1,
When the (keyhole closing device 11) has been inserted into the keyhole 3,
It can be easily shifted to a state where the lock pin 22 and the manhole cover 1 can be engaged.

The rod 4 of the electromagnetic solenoid 41
2 engages with the pin 36 and the rocking pin 22 is prevented from swinging, and when someone tries to forcibly pull out the keyhole closing device 11, an extremely large force is applied to the lock pin 2.
2 acts in the direction of swinging. However, since the keyhole closing device 11 has the speed increasing gear train 31 that speeds up the swing of the lock pin 22, the lock pin 22
An extremely large force acting on the pin 36 and the electromagnetic solenoid 41 (rod 42) is reduced. As a result, breakage of the pin 36, the electromagnetic solenoid 41, and the like can be prevented. Further, even if the locking force between the pin 36 and the rod 42 of the electromagnetic solenoid 41 is set to be small, the presence of the speed increasing gear train 31 increases the force for inhibiting the rock pin 22 from swinging. To
A small electromagnetic solenoid 41 having a small output can be used, and the size of the keyhole closing device 11 can be reduced.

When pulling out the keyhole closing device 11 inserted into the keyhole 3, the worker first sends a signal from the external terminal 61 to the control unit 51,
A control signal is output to the electromagnetic solenoid drive circuit 55 from 52a so that the electromagnetic solenoid 41 is in the excited state.
When the electromagnetic solenoid 41 is in the excited state, as described above, the lock pin 22 can swing, so that when the worker tries to pull out the keyhole closing device 11 using a special tool, the lock pin 22 As shown in FIG. 7, the manhole cover 1 comes into contact with the cover 1 and swings from the first swing position to the second swing position.
Will be released. Thereby, the keyhole closing device 11 can be extracted from the keyhole 3.

In the keyhole closing device 11 having the above-described structure, the force by which the worker lifts the keyhole closing device 11 directly acts on the lock pin 22 by the contact between the lock pin 22 and the manhole cover 1. Therefore, an extremely large force acts on the lock pin 22 in the direction of swinging the lock pin 22, and even when rust, dirt, or the like is attached to the lock pin 22, the lock pin 22 22 can be reliably swung, and the keyhole closing device 11 can be reliably removed from the keyhole 3.

Further, since the swing shaft 23 is supported by the bearing 25, grease or the like filled in the bearing 25 causes
The intrusion of liquid or gas into the body 12 (keyhole closing device 11) can be reliably prevented, and the operation of the lock mechanism 21 is not hindered.

(Second Embodiment) FIGS. 8 to 10 are schematic views showing the configuration of a keyhole closing device for a manhole cover according to a second embodiment of the present invention. The second embodiment is different from the first embodiment in the configuration of the lock mechanism 21.

The lock mechanism 121 of the keyhole closing device 111
The lock pin 22, as shown in FIGS.
Swing shaft 23, weight lever 124, electromagnetic solenoid 4
1 and the like. The weight lever 124 is
It is formed in a fan shape. Also, the weight lever 124
Is fixed to one end of the swing shaft 23, and the swing shaft 23 swings (swings in the direction of the arrow in FIG. 8) by the weight of the weight lever 124. Lock pin 2
2 is fixed to the swing shaft 23 so that the swing shaft 23 swings to the first swing position (the position shown in FIG. 10) when the swing lever 23 swings by its own weight. Have been. Here, the weight lever 124 constitutes a lock pin swing means in each claim.

A notch 124a is formed in the arc-shaped outer peripheral portion of the weight lever 124 so as to be able to engage with the rod 42 of the electromagnetic solenoid 41. Electromagnetic solenoid 41
The excited state and the non-excited state are controlled based on a control signal output from the control unit 51. The rod 42 of the electromagnetic solenoid 41 is in a protruding position when the electromagnetic solenoid 41 is not excited, and the lock pin 22
Is in the first swing position, the weight lever 12
4 with the notch 124a. Electromagnetic solenoid 4
When the first rod 42 and the notch 124a are engaged,
The swing of the weight lever 124 is restricted, and
The swing of the lock pin 22 is prohibited. The rod 42
Is set to the retracted position when the electromagnetic solenoid 41 is excited, and the engagement with the notch 124a is released.
Rod 42 of electromagnetic solenoid 41 and notch 124a
Is released, the weight lever 124 becomes swingable, and the lock pin 22 becomes swingable.

When the keyhole closing device 111 is inserted into the keyhole 3, the operator first sends a signal from an external terminal to the control unit 51, and the CPU sends the signal to the electromagnetic solenoid 41.
The control signal is output to the electromagnetic solenoid drive circuit so that the control signal is in the excited state. When the electromagnetic solenoid 41 is in the excited state, as described above, the lock pin 22 can be swung, so that the operator locks the lock pin 22 to the second swing position (locked to the recess 14 of the body 12). As shown in FIGS. 8 and 9, the keyhole closing device 111 is moved to the position where the pin 22 is almost entirely housed and the state in which the pin 22 can be engaged with the manhole cover 1 is released. Can be easily inserted into the keyhole 3.

When the insertion of the keyhole closing device 111 is completed, the lock pin 22 swings to the first swinging position by the weight of the weight lever 124 as shown in FIG. It can be engaged. In this state, the operator sends a signal from the external terminal 61 to the control unit 51, and causes the CPU to output a control signal to the electromagnetic solenoid drive circuit so that the electromagnetic solenoid 41 is in a non-excited state. When the electromagnetic solenoid 41 is in the non-excited state, as shown in FIG. 10, the notch 124a of the weight lever 124 and the electromagnetic solenoid 41
And the swing of the weight lever 124 is restricted, and the swing of the lock pin 22 is prohibited.
Accordingly, when someone tries to pull out the keyhole closing device 111 from the keyhole 3, the lock pin 22 and the manhole cover 1 are engaged with each other.
Can be prevented from being extracted.

In the keyhole closing device 111 having the above-described configuration, the weight lever 124 is provided as described above, and the lock pin 22 swings to the first swing position by the weight of the weight lever 124. And the manhole cover 1 can be engaged with the lock pin 22 and the manhole cover 1 when the body 12 (the keyhole closing device 111) is completely inserted into the keyhole 3. Easy migration.

When pulling out the keyhole closing device 111 inserted in the keyhole 3, first, the worker sends a signal from the external terminal 61 to the control unit 51,
A control signal is output from U to the electromagnetic solenoid drive circuit so that the electromagnetic solenoid 41 is in the excited state. When the electromagnetic solenoid 41 is in the excited state, as described above, the lock pin 22 can swing, so that when the worker tries to pull out the keyhole closing device 111 using a special tool, the lock pin 22 In contact with lid 1,
The swinging operation is performed from the first swinging position to the second swinging position, so that the engagement with the manhole cover 1 is released. Thereby, the keyhole closing device 111 can be extracted from the keyhole 3.

In the keyhole closing device 111 having the above-described configuration, the force by which the worker lifts the keyhole closing device 111 directly acts on the lock pin 22 by the contact between the lock pin 22 and the manhole cover 1. Therefore, an extremely large force acts on the lock pin 22 in the direction of swinging the lock pin 22, and even when rust, dirt, or the like is attached to the lock pin 22, the lock pin 22 22 can be reliably swung, and the keyhole closing device 111 can be reliably removed from the keyhole 3.

Further, since the lock mechanism 121 includes the lock pin 22, the swing shaft 23, the weight lever 124, and the electromagnetic solenoid 41, the configuration of the lock mechanism 121 becomes simple, and It is possible to reduce the size and cost.

In the second embodiment, a notch 124a is provided in the weight lever 124 so as to engage with the rod 42 of the electromagnetic solenoid 41.
Although the swing of the lock pin 22 is prohibited, the structure for inhibiting the swing of the lock pin 22 is not limited to this. For example, a lever having a claw that can be engaged with an end of the weight lever 124 is provided. A member may be provided, and this lever member may be operated by the electromagnetic solenoid 41.

In the first and second embodiments,
Although the electromagnetic solenoid 41 is used as the actuator, the invention is not limited to this, and another actuator such as a stepping motor may be used.

[0048]

As described above, according to the present invention, it is possible to realize a manhole cover keyhole closing device capable of reliably removing the manhole cover from the keyhole.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of a keyhole closing device for a manhole cover according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a keyhole closing device for a manhole cover according to the first embodiment of the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

FIG. 5 is a block diagram showing a configuration of a control unit included in the manhole cover keyhole closing device according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a configuration of a keyhole closing device for a manhole cover according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a configuration of a keyhole closing device for a manhole cover according to the first embodiment of the present invention.

FIG. 8 is a schematic diagram showing a configuration of a keyhole closing device for a manhole cover according to a second embodiment of the present invention.

FIG. 9 is a schematic diagram illustrating a configuration of a keyhole closing device for a manhole cover according to a second embodiment of the present invention.

FIG. 10 is a schematic diagram showing a configuration of a keyhole closing device for a manhole cover according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Manhole cover, 3 ... Keyhole, 11,111 ... Keyhole closing device, 12 ... Trunk, 13 ... Lid, 14 ... Depression, 21, 1
DESCRIPTION OF SYMBOLS 21 ... lock mechanism part, 22 ... lock pin, 23 ... rocking shaft, 24 ... gear, 25 ... bearing part, 26 ... torsion spring, 31 ... speed-up gear train, 32 ... 1st gear pair, 33
... second gear pair, 34 ... third gear pair, 35 ... fourth gear pair, 36 ... pin, 41 ... electromagnetic solenoid, 42 ... rod, 51 ... control unit, 61 ... terminal, 124 ... weight Lever, 124a: Notch.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Soichi Takahashi 2-3-2, Shimomeguro, Meguro-ku, Tokyo Inside Tamura Electric Works, Ltd. (72) Inventor, Masashi Mizutani 1-22-2, Nishishinjuku, Shinjuku-ku, Tokyo No. Haneda Fume Tube Co., Ltd. F-term (reference) 2D047 BB01 2D063 CB27 2E250 AA00 BB08 DD01 FF26 FF36

Claims (3)

[Claims] 1. A keyhole closing device for a manhole cover, which is inserted into a keyhole formed in a manhole cover to close the keyhole, comprising: a body inserted into the keyhole; In the first swing position, a part thereof projects from the outer periphery of the body to be engaged with the manhole cover, and in the second swing position, A lock pin which is released from the state in which the lock pin can be engaged with the manhole cover; and a lock pin swing for inhibiting the lock pin from swinging when the lock pin swings to the first swing position. Prohibiting means, wherein the lock pin comes into contact with the manhole cover when the body is pulled out of the keyhole, and the second swing from the first swing position. Man swinging toward position Keyhole closure device Lumpur lid. 2. The apparatus according to claim 1, further comprising a lock pin swing means for swinging the lock pin so that the first swing position is set to an initial state of the lock pin. 4. The keyhole closing device for a manhole cover according to claim 1. 3. A gear that rotates integrally with the lock pin, and a gear train that meshes with the gear to increase the speed of rotation of the gear, further comprising a gear at the end of the gear train. A pin is protruded from the pair, and the lock pin swing prohibition means engages with the pin,
3. The keyhole closing device for a manhole cover according to claim 1, further comprising solenoid means for stopping the rotation of the terminal gear pair.