JP7657752B2 - Remote control device and remote control method - Google Patents

Description

An embodiment of the present invention relates to remote control technology.

In the event of a serious accident at a nuclear power plant, gas will be generated by melted nuclear fuel inside the reactor pressure vessel. This gas could cause the pressure in the reactor containment vessel to exceed the pressure limit considered in the design, leading to its rupture. The Nuclear Regulation Authority has therefore requested that power companies take measures to release the pressure in the reactor pressure vessel. For this reason, nuclear power plants are equipped with vent valves. These vent valves are motorized valves that can be operated with a DC power source so that they can still function in the event of a loss of AC power. Furthermore, the Nuclear Regulation Authority has requested that power companies take into consideration the possibility of a total power loss and take measures to "mechanically" operate the vent valve by transmitting a manually generated force.

In addition, power companies voluntarily request that equipment suppliers be able to close the vent valve after venting and to construct the boundary of the reactor pressure vessel. As a means of realizing this requirement, for example, a technology is known in which the torque generated by turning a handle installed outside the reactor building is transmitted to the motor-operated valve via a flexible shaft. However, when multiple flexible shafts are connected, the torque transmission efficiency decreases. Therefore, a reduction gear must be installed along the way. In addition, when opening and closing the vent valve, the handle must be rotated several thousand times. Therefore, a technology is known in which a device like a "bicycle" is used as a means of generating torque by human power. However, in a torque transmission mechanism in which multiple flexible shafts are connected, the handle must be rotated several thousand times, making it difficult to open and close the vent valve within the required time. Therefore, there is a demand for improving the torque transmission efficiency.

Patent No. 5976518 Patent No. 6650590

The problem that this invention aims to solve is to provide a remote control technology that can improve the efficiency of torque transmission.

A remote control device according to an embodiment of the present invention comprises a shaft that transmits torque and has rigidity, a bearing that supports the shaft rotatably around its axis, and a fastener that fixes the bearing to at least one of a wall, ceiling, or floor of a building in which equipment that is installed in a nuclear power plant and is the subject of operation, a valve that is operated to open or close when power is lost at the nuclear power plant, and a torque transmission path is formed by connecting a plurality of the shafts and transmitting the torque from an operation unit to which the torque is input to the equipment, and further comprises a flexible shaft that forms part of the torque transmission path and has flexibility, and a penetrating shaft that forms part of the torque transmission path and penetrates at least one of the wall, ceiling, or floor, the building includes a first building and a second building, the torque transmission path is formed from the first building to the second building, and the flexible shaft is provided at the boundary between the first building and the second building .

Embodiments of the present invention provide remote control technology that can improve torque transmission efficiency.

FIG. 1 is a configuration diagram showing an overall image of a remote control device according to an embodiment of the present invention. FIG. 4 is a perspective view showing a plurality of shaft units provided on a wall surface. FIG. IV-IV cross-sectional view of Figure 3. FIG. 2 is a cross-sectional view showing the through shaft and crank handle. FIG. 11 is a cross-sectional view showing a shaft unit according to a modified example.

Below, an embodiment of a remote control device and a remote control method will be described in detail with reference to the drawings.

The reference numeral 1 in FIG. 1 denotes a remote control device of this embodiment. This remote control device 1 remotely operates equipment installed in a specific building. For example, a nuclear power plant building is shown as an example of a building. This building is provided with a vent valve 2 as the equipment to be operated.

In a nuclear power plant, if a total loss of power occurs and it becomes impossible to cool the reactor, the pressure inside the reactor containment vessel may increase, leading to risk of damage. To prevent this damage, a process known as venting is performed to exhaust the atmosphere inside the reactor containment vessel to the outside. Vent valve 2 is installed between the reactor containment vessel and the exhaust stack. An operator opens vent valve 2 when venting begins, and closes vent valve 2 when venting ends.

In other words, the vent valve 2 is operated to be opened or closed in the event of a total power loss at the nuclear power plant. The remote control device 1 allows an operator to operate the vent valve 2 remotely. Furthermore, by installing this remote control device 1 in advance, an operator can manually open or close the vent valve 2 in the event of a total power loss. Furthermore, the remote control device 1 does not require any electricity to operate, and is a "mechanical" device that can be operated solely by human power.

The remote control device 1 may be installed when a building is newly constructed, or may be installed later in an existing building that has been built for some time. The remote control device 1 may also be installed temporarily (temporarily).

The remote control device 1 comprises a shaft unit 3, a universal joint 4, a flexible shaft 5, a through shaft 6, and a crank handle 7. These components are linearly connected and extend from the manual operation chamber to the vent valve 2.

The crank handle 7 is an operating part where torque is input by manual operation by an operator. This crank handle 7 is installed in a manual operation room away from the vent valve 2. This manual operation room is shielded from radiation from the reactor, and is a place where operators can work safely.

In this embodiment, multiple shaft units 3, universal joints 4, flexible shafts 5, and through shafts 6 are connected to form a torque transmission path that transmits torque from the crank handle 7 to the vent valve 2.

The vent valve 2 is provided with a drive unit 8 such as a reducer. The remote control device 1 is connected to this drive unit 8, and the torque for operating the vent valve 2 is transmitted.

As shown in FIG. 2, the shaft units 3 are installed along the walls, ceiling, and floor, which are the structural members 9 of the building. For example, the shaft units 3 are installed at a position slightly away from the surface of the walls. The universal joints 4 connect the multiple shaft units 3 to each other.

For example, the shaft unit 3 is fixed to a structural material 9 such as a wall of a building by a fixing device 10. If the wall is bent at a right angle in plan view, a universal joint 4 is placed at the corner. This universal joint 4 connects the shaft units 3 provided on one wall and the other wall to each other. This universal joint 4 may be provided at a corner between the wall and the floor, or at a corner between the wall and the ceiling.

As shown in FIG. 1, the flexible shaft 5 forms part of the torque transmission path and has flexibility. In this way, the relative displacement that occurs in the building or equipment is absorbed by the flexible shaft 5.

For example, a torque transmission path is formed from the first building to the second building. Here, a flexible shaft 5 is provided at the boundary B between the first building and the second building. Each building shakes differently during an earthquake due to differences in structure, size, foundation (base) strength, etc. By providing the flexible shaft 5 at the boundary B, the difference in shaking that occurs during an earthquake, the so-called relative displacement, can be absorbed, and the remote control device 1 is not damaged.

A flexible shaft 5 is provided between the shaft unit 3 and the vent valve 2. Here, the shaft unit 3 is fixed to a structural material 9 of the building, such as a wall. Meanwhile, the vent valve 2 is fixed to equipment such as piping (not shown). As a result, the shaft unit 3 and the vent valve 2 shake in different ways when an earthquake occurs. By providing the flexible shaft 5 between the shaft unit 3 and the vent valve 2, the relative displacement that occurs between the shaft unit 3 and the vent valve 2 can be absorbed, preventing damage to the remote control device 1.

In this way, flexible shafts 5 are placed in locations where there is the effect of relative displacement due to earthquakes or where the torque transmission path needs to be bent. On the other hand, shaft units 3 are placed in locations where the effect of relative displacement due to earthquakes can be ignored or where the torque transmission path is linear.

For example, the occurrence of a huge earthquake could lead to a serious accident at a nuclear power plant. In this embodiment, the remote control device 1 is configured by appropriately combining the shaft unit 3 and the flexible shaft 5, thereby improving earthquake resistance. In addition, by appropriately designing the arrangement of the shaft unit 3 and the flexible shaft 5, the stress generated by earthquake inertia forces can be suppressed to below the allowable value of the remote control device 1.

As shown in Figures 3 and 4, the shaft unit 3 includes a shaft 11, a bearing 12, and an outer cylinder 13.

The shaft 11 is a rod-shaped member that transmits torque and has rigidity. The bearing 12 supports the shaft 11 so that it can rotate about its axis. For example, the bearing 12 is configured by arranging multiple balls in the circumferential direction of the shaft 11 and further arranging balls in the longitudinal direction of the shaft 11. The bearing 12 may be configured not only using balls, but also using rollers.

The outer tube 13 is a hollow cylindrical member that covers the entire outer circumference of the shaft 11 in the longitudinal direction. The bearing 12 is provided inside the outer tube 13. In this way, the shaft 11 and the bearing 12 can be protected by the outer tube 13. In addition, because the shaft 11 and the bearing 12 are integrated, the shaft 11 can be easily installed on a wall surface, etc.

The outer cylinder 13 may be a so-called split member that can be divided into two in the radial direction. Splitting the outer cylinder 13 in half makes it easier to place components such as the shaft 11 or bearing 12 inside. The split members are then joined together by welding.

The shaft 11 protrudes from both ends of the outer tube 13. The ends of this shaft 11 are connected to another shaft 11, a universal joint 4, a flexible shaft 5, or a through shaft 6. A specific attachment 22 (Figure 5) that is easy to attach and detach is used to connect such members to each other.

The outer cylinder 13 also has multiple partitions 14 that divide its interior in the longitudinal direction. For example, plate-shaped and annular partitions 14 are provided on the inner peripheral surface of the outer cylinder 13, protruding inward. A hole through which the shaft 11 is inserted is formed in the center of the partition 14. This makes it difficult for atmosphere containing steam from the outside to enter the inside of the outer cylinder 13, thereby suppressing deterioration of the shaft 11 and bearings 12. In addition, external heat is less likely to be transmitted to the shaft 11 and bearings 12, suppressing deformation of the shaft 11 and bearings 12 due to heat.

For example, if a serious accident occurs at a nuclear power plant, the building will be filled with steam and radiation. To prevent the shaft 11 and bearings 12 from being directly exposed to this steam, a partition 14 is provided inside the outer cylinder 13. In this way, malfunctions of the shaft 11 and bearings 12 can be suppressed.

A disk-shaped positioning plate 15 is fixed to the shaft 11. The positioning plate 15 comes into contact with the partition portion 14, thereby positioning the shaft 11 so that it does not shift in the axial direction (longitudinal direction).

The fixture 10 fixes the outer cylinder 13 to at least one of a wall, ceiling, and floor. Furthermore, a bearing 12 is fixed to this outer cylinder 13. In other words, the fixture 10 prevents the bearing 12 from rotating relative to the wall or the like. The shaft 11 rotates around its axis while supported by the bearing 12.

For example, as shown in FIG. 4, the fixing device 10 has a main body 16 that is a plate (or block) bent into an L-shape. This main body 16 is fixed to a structural material 9 such as a wall surface using anchor bolts 17 or the like. The shaft unit 3 is placed on the main body 16 and fixed to the main body 16 using mounting brackets 18 or the like. The outer tube 13 of the shaft unit 3 may be welded to the main body 16 of the fixing device 10, or may be fixed using screws (not shown) or the like.

As shown in FIG. 2, the universal joint 4 forms part of the torque transmission path and connects the shaft 11 of one shaft unit 3 to the shaft 11 of the other shaft unit 3. By providing the universal joint 4, whose angle can be freely changed, between two shafts 11 with different angles or directions, the torque transmission path can be freely bent and a large torque can be transmitted.

As shown in FIG. 1, the through shaft 6 forms part of the torque transmission path and penetrates at least one of the wall, ceiling, and floor. In this way, a torque transmission path can be formed by penetrating the structural material 9 of the building that constitutes the wall, etc.

For example, the structural material 9 of the building is hollowed out to the same size as the diameter of the through shaft 6, and the through shaft 6 is inserted. The outer periphery of the through shaft 6 is then fixed to the structural material 9 with mortar or the like.

As shown in FIG. 5, the through shaft 6 comprises a shaft 19, a bearing 20, and an outer cylinder 21.

The shaft 19 is a rod-shaped member that transmits torque and has rigidity. In addition, bearings 20 are provided at one and the other ends of the outer cylinder 21. The shaft 19 is supported by these bearings 20 so that it can rotate around its axis.

For example, a through shaft 6 is provided penetrating the structural material 9 of the wall facing the manual operation room. A shaft unit 3 is connected to one end of the through shaft 6 using a specified attachment 22. Furthermore, a crank handle 7 is connected to the other end of the through shaft 6 using another attachment 22. When an operator manually turns the crank handle 7 to input torque, this torque is transmitted to the vent valve 2 (Figure 1) via the torque transmission path.

The shaft unit 3 of this embodiment has a so-called double-tube structure consisting of a shaft 11 and an outer tube 13. The arrangement of bearings 12 on the outer tube 13 facilitates rotation of the shaft 11, and the high rigidity of the shaft 11, which corresponds to the inner tube, allows torque to be transmitted efficiently. The double-tube structure also improves earthquake resistance and durability.

Also, by providing the outer cylinder 13 on the shaft unit 3, there is no risk of people nearby coming into contact with the rotating shaft 11, improving safety. Furthermore, dust and other floating objects do not become clogged in the bearing 12, preventing malfunction of the bearing 12.

In addition, if a serious accident occurs at a nuclear power plant, the shaft unit 3 will be exposed to radiation, heat, steam, etc. For example, there is a risk that the grease in the bearings 12 will dry out and cause malfunctions, but in this embodiment, the shaft unit 3 has a double-tube structure, so that the shaft 11 and bearings 12 are not directly exposed to radiation, heat, steam, etc., and robustness is improved.

Next, a modified shaft unit 3A will be described with reference to FIG. 6. Note that components that are the same as those shown in the previously described embodiment will be given the same reference numerals and duplicated descriptions will be omitted. The configuration applied in this modified example may be applied to the previously described embodiment, or may be combined as appropriate.

In this modified example, the outer tube 13A is provided so as to cover a portion of the shaft 11 in the longitudinal direction. For example, the outer tube 13A is provided in a portion of the shaft 11 that corresponds to the fixing device 10. If one shaft 11 is supported by multiple fixing devices 10, multiple outer tubes 13A corresponding to the respective fixing devices 10 are provided. The outer tube 13A may be integrated with the fixing device 10.

A partition 14 is provided at the end of the outer cylinder 13A. A plurality of ball bearings 23 are provided inside the outer cylinder 13A. These ball bearings 23 support the shaft 11 in the radial direction and also support the shaft 11 so that it can rotate about its axis. Note that a roller bearing may be used to support the shaft 11.

In addition, two thrust ball bearings 24 are provided inside the outer cylinder 13A so as to sandwich the positioning plate 15 of the shaft 11. These thrust ball bearings 24 contact both sides of the positioning plate 15 and rotatably support the positioning plate 15. The thrust ball bearings 24 reduce frictional resistance caused by the rotation of the shaft 11 while preventing the shaft 11 from shifting in the axial direction (longitudinal direction).

In the above embodiment, the vent valve 2 is exemplified as the device to be operated, but other configurations are also possible. For example, the device to be operated may be a valve for operating an emergency condenser in the event of a total power loss at a nuclear power plant.

In the above embodiment, the crank handle 7 as the operating part is provided in the manual operation room, but other configurations are also possible. For example, the crank handle 7 may be provided on the outer wall of a building, and an operator may input the torque outdoors.

In the above embodiment, a crank handle 7 is exemplified as the operating unit, but other configurations are also possible. For example, a specified impact driver may be connected to the operating unit, and torque may be input to the operating unit by this impact driver. Also, a bicycle equipped with a specified mechanism for torque transmission may be connected to the operating unit, and torque may be input to the operating unit by this bicycle.

According to the embodiment described above, by providing a shaft 11 that transmits torque and has rigidity, the torque transmission efficiency can be improved.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments or modifications thereof are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and spirit of the invention.

1... remote control device, 2... vent valve, 3 (3A)... shaft unit, 4... universal joint, 5... flexible shaft, 6... through shaft, 7... crank handle, 8... drive unit, 9... structural material, 10... fixing device, 11... shaft, 12... bearing, 13 (13A)... outer cylinder, 14... partition section, 15... positioning plate, 16... main body, 17... anchor bolt, 18... mounting bracket, 19... shaft, 20... bearing, 21... outer cylinder, 22... attachment, 23... ball bearing, 24... thrust ball bearing, B... boundary.

Claims (7)

a shaft that transmits torque and has rigidity;
a bearing that supports the shaft so as to be rotatable about its axis;
a fixture for fixing the bearing to at least one of a wall surface, a ceiling, and a floor surface of a building in which a valve, which is a device that is installed in a nuclear power plant and is subject to operation and is opened or closed when a power source of the nuclear power plant is lost , is installed;
Equipped with
A plurality of the shafts are connected to each other to form a torque transmission path for transmitting the torque from an operation unit to which the torque is input to the device,
A flexible shaft that forms a part of the torque transmission path and has flexibility;
A through shaft that forms a part of the torque transmission path and penetrates at least one of the wall surface, the ceiling, and the floor surface;
Further equipped with
the building includes a first building and a second building, the torque transmission path is formed from the first building to the second building, and the flexible shaft is provided at a boundary between the first building and the second building.
Remote control device. an outer cylinder covering the outer periphery of the shaft over the entire longitudinal direction and having the bearing provided therein;
The remote control device according to claim 1 . An outer cylinder is provided which covers the outer periphery of the shaft locally in the longitudinal direction and has the bearing provided therein.
The remote control device according to claim 1 . The outer cylinder has a partition portion that divides the inside.
The remote control device according to claim 2 or 3. The bearing is structured so that the bearing is not directly exposed to the outside air by the outer cylinder and the partition portion, and grease is sealed in the bearing.
The remote control device according to claim 4. a universal joint that forms a part of the torque transmission path and connects one of the shafts to the other of the shafts;
The remote control device according to any one of claims 1 to 5 . a shaft that transmits torque and has rigidity;
a bearing that supports the shaft so as to be rotatable about its axis;
a fixture for fixing the bearing to at least one of a wall surface, a ceiling, and a floor surface of a building in which a valve, which is a device that is installed in a nuclear power plant and is subject to operation and is opened or closed when a power source of the nuclear power plant is lost , is installed;
Equipped with
A torque transmission path is formed by connecting a plurality of the shafts,
A flexible shaft that forms a part of the torque transmission path and has flexibility;
A through shaft that forms a part of the torque transmission path and penetrates at least one of the wall surface, the ceiling, and the floor surface;
Further equipped with
the building includes a first building and a second building, the torque transmission path is formed from the first building to the second building, and the flexible shaft is provided at a boundary between the first building and the second building.
A method using a remote control device , comprising :
The torque is transmitted from an operation unit to which the torque is input to the device via the torque transmission path.
Remote operation method.

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