JPS632062B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic attraction type moving device that moves along the surface of a structure made of, for example, an iron plate, and performs various inspections, maintenance work, etc.

For example, in large systems such as chemical plants and nuclear reactors, in order to maintain the integrity of each part element or welded part of the structure during operation, it is necessary to patrol the inside of these plant equipment and carry out maintenance work. There is. However, as these systems such as plants and nuclear reactors become larger and more densely packed, the accessibility to inspection and maintenance parts tends to deteriorate, making it difficult for inspectors to approach them. be.

In particular, nuclear power plants are required to undergo periodic inspections from the perspective of safety management, but in-service inspections (in-service inspections)
Even when conducting inspections (ISI), there are severe restrictions on inspectors staying inside the reactor for long periods of time to prevent exposure to radiation. That is,
Inspection and maintenance work is required to be carried out without human assistance in the complex environment inside a nuclear reactor, so inspection and maintenance equipment must be transported,
Moreover, there is a desire to develop a device that can serve as a scaffold to ensure that this work can be carried out.

It has been considered to use, for example, permanent magnets that are attracted to iron plates, which are the structures inside these furnaces, as a moving device that transports such inspection and maintenance equipment and also serves as a scaffold. For example, a mobile platform whose wheels are made of permanent magnets and which moves while adhering to the iron plate surface is considered for transporting nuclear reactor ISI equipment. Since the area of the attraction surface of the permanent magnet cannot be increased, the attraction and retention force is extremely weak. For this reason, it has been considered to construct a mobile vehicle with endless tracks instead of wheels, and to construct the endless tracks with permanent magnets. In this way, the attraction area of the permanent magnet to the iron plate surface can be set sufficiently large, but it is difficult to change the direction within a particularly small area range while attracting and moving, and it is also difficult to change the direction within a particularly small area range while attracting and moving. There is a high possibility of injury.

In addition, it is possible to use an electromagnet to attract and hold the moving object on the iron plate surface without using a permanent magnet, and move it forward by switching and controlling the excitation current, but it is necessary to set a sufficient attracting force using the electromagnet. This is difficult, and requires a very large amount of power at all times to ensure sufficient power.

This invention was made in view of the above points, and uses a permanent magnet as an adsorption means for the iron material that makes up the structure, and while setting a sufficient adsorption force, it is possible to freely touch the surface of the iron material. It is an object of the present invention to provide a mobile device that can be moved to effectively perform transportation, inspection, and maintenance work on, for example, nuclear reactor ISI equipment. .

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows its basic configuration, which includes first and second supports 11 and 12 that are stacked one on top of the other. Rods 13 and 14 are provided that extend to. And this rod 13,1
A first permanent magnet 15a,
15b and second permanent magnets 16a, 16b.
a and 16b are adsorbed to the surface of the structural iron plate. In this case, the first and second supports 1
1 and 12 are movable in directions toward or away from each other as shown by arrow 17, and rods 13 and 14 are movable relative to supports 11 and 12, respectively, as shown by arrows 18 and 19. Set to be movable.

That is, in the state shown in the figure, the permanent magnets 15a, 15
b, 16a, 16b are attracted and fixed to the surface of the iron plate, and if the supports 11, 12 are driven to separate, the permanent magnets 15a, 15b are separated from the surface of the iron plate using the permanent magnets 16a, 16b as legs. They are pulled apart and the adsorption state is released. and,
In this state, if the second support 12 is moved relative to the rod 14, the first permanent magnets 15a, 15b are moved parallel to the rod 14, and the mutual spacing between the supports 11, 12 is returned to the original. Therefore, the first permanent magnet 1
5a and 15b are again attracted to the surface of the iron plate at different positions.

Then, in this state, if the supports 11 and 12 are driven to approach each other, the second permanent magnets 1 and 15 will be moved with the first permanent magnets 15a and 15b as legs.
6a and 16b are separated from the surface of the iron plate, and their adsorption state is released. This second permanent magnet 16a,
With the suction state of 16b released, press the rod 1 again.
4 relative to the support 12 in the opposite direction to the above case, and the mutual spacing between the supports 11 and 12 is returned to the original, the permanent magnets 15a, 15b, 16a, 16
b is all attracted to the surface of the iron plate, and the entire device is moved in the direction in which the rod 14 extends.

That is, the mutual positional relationship of the supports 11 and 12,
By controlling the sliding position of the rods 13, 14 relative to the supports 11, 12, the device can be moved freely oriented, for example, over the surface of an iron plate.

That is, in the device configured in this way, half of the total attraction surface of the set permanent magnet is always used in a state where it is attracted to the surface of the iron plate that is the object. Also, for permanent magnets levitated from the iron plate surface, if the levitation distance is set to a minute value,
While the resistance to movement in the sliding direction is sufficiently small, a state is set in which a considerable magnetic attraction force is exerted on the iron plate surface, and a state is maintained in which a very large magnetic attraction force is set overall.

In addition, the force required when moving this device is for the vertical movement of the permanent magnet and the sliding movement in the floating state. Of these, the force for the vertical movement is due to the minute movement stroke. Therefore, actual power consumption can be reduced. In addition, the sliding motion of the levitated permanent magnet is
This is the direction perpendicular to the magnetic attraction force that acts. Therefore, by constructing the slide mechanism with a sufficiently smooth and robust roller bearing, etc., it is possible to avoid the resistance force from the attraction by the permanent magnet, and the slide movement can be controlled with a sufficiently small force. can be executed. On the steel ring, the only resistance is due to eddy currents generated on the iron plate.

Let us consider more specifically the characteristics of the device as described above. First, considering the magnetic attraction force caused by a permanent magnet, the attraction force F (dyne) of a magnet is generally expressed as follows: When there is no gap in the magnetic path of a magnetic circuit, the cross section of the magnetic path is S (cm ² ), and the magnetic flux density is B(G)
In this case, it is shown by the following formula.

F=SB ² /8π Therefore, for example, if a rare earth cobalt magnet with a residual magnetic flux of 8000 (G) is used, the attractive force per unit area will be 2.6 (Kg/cm ² ). According to actual measurements, the attraction force of the above magnet with a thickness of 6 mm is 1.4 (Kg/
cm ² ) can be measured.

Therefore, for example, even if the area of the attracting surface of one of the first and second permanent magnets is 200 (cm ² ), the attracting force will be 280 kg, and the By combining the attraction forces, it is possible to easily obtain sufficient magnetic attraction force to support the weight of not only the permanent magnet itself but also the inspection equipment, etc., and furthermore, to serve as a scaffold for inspection. , can be confirmed.

Next, when we estimate the power consumption required to move this device, we get the following. First, the force consumed when the floating permanent magnet slides on the iron plate while keeping it at a very small distance is due to the generation of eddy currents. This can be largely ignored since the slide speed is set to a fairly low speed for practical purposes. Therefore, the largest force consumed during this movement is to separate the permanent magnet adhering to the iron plate surface and make it levitate.

For example, if we assume that the first and second permanent magnets are in close contact with the iron plate surface, then one of them is floated by 0.5 mm and then moved in a sliding motion, the stroke for switching between the magnets on the close side and the floating side is is 1mm. Therefore, if the suction force is always 300 kg and the switching operation is performed in 2 seconds, the required force at that time is 1.5 watts. This is a force that can be sufficiently generated by a small DC motor, and in reality, it can be converted into high pressure and minute vertical motion using an appropriate high reduction ratio transmission.

This vertical movement only needs to be performed within the range where the stroke movement of the floating permanent magnet does not cause mechanical contact with the iron plate surface, thus improving the accuracy of the device and reducing its travel distance. This also makes it possible to achieve high-speed switching operations with even smaller forces.

Figures 2 to 4 show a device that further embodies the above-mentioned principle device, and this device is capable of adsorbing onto the cylindrical surface of a nuclear reactor steam drum with a diameter of 2 m and a length of 16 m. An example of moving in the direction is shown.

That is, this device includes a pair of first permanent magnets 15 and a pair of second permanent magnets 16a and 16b arranged at linear positions on both sides of the first permanent magnets 15. . The first and second permanent magnets 15, 16a, 16 arranged in a straight line
The suction surface b is formed on the same cylindrical surface coaxially to match the outer peripheral surface shape of the steam drum.

In this case, the axis of the cylindrical surface is set parallel to the direction in which the permanent magnets 15a, 16a, and 16b are arranged in the example shown in the figure, but this may be a cylindrical surface whose axis is orthogonal to the direction in which the permanent magnets are arranged. .

For the first permanent magnet 15 located in the middle, there is a first permanent magnet on the upper surface side opposite to the lower attracting surface.
A support body 11 is integrally provided. This first support body 11 is provided with a pair of roller guides 20a, 20b so as to extend in a direction perpendicular to the direction in which the magnets 15, 16a, 16b are lined up. The two legs of the intermediate support 21 are connected via. That is, the intermediate support 21 is mechanically coupled to the first support 11 and the roller guide 20
It is set to be slidable in the extending direction of a and 20b.

Further, in relation to the first support 11, a first
The worm wheel 22 is integrally attached to the permanent magnet 15 of
will be provided. This worm wheel 22 is located between the roller guides 20a and 20b, and is set parallel to the direction in which the roller guides 20a and 20b extend.If the worm wheel 22 is attached to the intermediate support 21 with its axes parallel to each other, it is meshed with the home gear 23. This worm gear 23
The rotation of the intermediate support 2 is reversibly controlled by a geared motor 24 attached to the intermediate support 21.
1, the sliding movement of the first permanent magnet 15 is controlled as described above. In this case, along with the worm wheel 22, the roller guide 20
By setting a and 20b in an arc shape corresponding to the attractive arc surface of the permanent magnet 15, the permanent magnet 15
The slide position is controlled along the cylindrical outer peripheral surface of the steam drum to be adsorbed, and the slide stroke is set to, for example, ±40 mm.

The second permanent magnets 16a and 16b located on both sides of the first permanent magnet 15 are integrally attached to a pair of support legs 12a and 12b provided at both ends of the second support body 12. This pair of support legs 12
The main body of the second support 12 that connects the parts a and 12b has a flat plate shape as shown in cross section in FIG. 5, and is set inside the external support 25. The external support 25 is composed of a pair of plates 25a and 25b that are spaced apart from each other. set to be located.

Here, the plates 25a and 25b of the external support 25
and the second support 12, there are oil bags 26a and 26b, respectively, as shown enlarged in FIG.
An oil pump 27 is used to control the amount of oil in and out of the oil bags 26a and 26b. That is, by controlling the amount of oil in the oil bags 26a, 26b to increase or decrease reciprocally, the positional relationship between the external support 25 and the second support 12 can be variably controlled in the direction perpendicular to the attraction surface by the permanent magnet. will be done.

The internal support body 21 is set to be located below the external support body 25, and the roller guides 20a and 20 are provided on opposing surfaces thereof, respectively.
Roller guides 28, 2 extending in a direction perpendicular to b
9, and they are connected to each other by roller bearings. That is, the internal support 21 and the external support 25 are integrally connected, and the roller guide 2
8 and 29 so as to be slidable relative to each other in the extending direction.

A geared motor 30 is mounted on this external support 25 in parallel with the roller guides 28 and 29.
A ball screw 31 whose rotation is reversibly controlled is provided, and this ball screw 31 is set to be threadedly engaged with the internal support 21. That is, by rotating the ball screw 31 by the geared motor 30, the positional relationship of the internal support 21 with respect to the external support 25 is controlled.

That is, in the device configured as described above, the first and second permanent magnets 15, 16a,
First and second supports 11,1 for 16b
2 is the relative positional relationship between the first magnet 15 and the second magnets 16a and 16b, which are connected by an internal support 21 and an external support 25, and are perpendicular to the magnetic attraction surface of the steam boiler. , that is, the first
The movement relative to the arrow 17 in the figure is executed by oil control by the oil pump 27 on the oil bags 26a, 26b. By controlling the rotation of the worm gear 23 and ball screw 31 by the geared motors 24 and 30, movements corresponding to arrows 18 and 19 in FIG. 1 are set. It sticks to a surface and moves arbitrarily on its outer circumferential surface.

Here, the first and second permanent magnets 15, 16
Assume that the effective area by a and 16b is 192 cm ² ,
If the entire surface is made into a magnetic adsorption surface, it is possible to obtain a maximum adsorption force of 270 kg on just one side.
When the machine is stopped, which serves as a platform for actual inspection and maintenance work, both magnets come into close contact with each other, producing twice the attraction force.

In other words, due to such strong adsorption power,
For example, it is a device that is reliably adsorbed to the outer peripheral surface of a steam boiler and moves smoothly on that surface, and the external support 25 can be used as a support for inspection and transportation of maintenance equipment. There is something.

For example, when used for ISI inspection of a nuclear reactor steam boiler, a computer for the inspection device, a device for easily and securely setting and removing this device from the steam boiler, and a dustproof skirt are installed on this device. etc. may be additionally set as appropriate.
Further, this device can be widely applied not only to the steam boiler described in the above embodiment, but also to various other works such as inspection and maintenance of other chemical plants.

In addition, in the example, the two sets of magnets are different from each other.
Although shown as sliding in one direction, in the case of an object that only needs to move in one direction, the sliding movement may be made only in one specified direction.

As described above, according to the present invention, it is possible to obtain a moving device that can move freely on various structures made of iron materials to effectively carry out various tasks such as inspection and maintenance, and which can be used within a nuclear reactor. This makes it possible to very effectively carry out work on structures, chemical plants, and other parts that are difficult to perform manually.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the principle of a moving device according to an embodiment of the present invention, FIG. 2 is a partially cutaway front view of a similar specific embodiment, and FIG. 3 is a diagram similar to that shown in FIG. Partially sectional view along the line, No. 4
The figure is a partially sectional plan view, and FIG. 5 is a cross-sectional view illustrating the relationship between the second support and the external support. 11...first support body, 12...second support body, 15, 15a, 15b...first permanent magnet,
16a, 16b...second permanent magnet, 20a, 2
0b, 28, 29... Roller guide, 21... Internal support, 22... Worm wheel, 23...
Worm gear, 24, 30...geared motor,
25... External support body, 26a, 26b... Oil bag, 27... Oil pump, 31... Ball screw.

Claims (1)

[Claims] 1. First and second permanent magnets each having an adsorption surface that comes into close contact with the surface of the iron material to be moved; and a surface along the surface of the iron material to which the first and second permanent magnets are attached, respectively. first and second support mechanisms that are slidably coupled in at least one direction intersecting each other; Corresponding to the mutual positional relationship in the height direction, the first
A moving device comprising: and a connecting mechanism capable of separating the second permanent magnet and the surface of the iron material one by one.