JPH08265914A - High temperature superconducting magnetic levitation transfer system - Google Patents

Abstract

PURPOSE: To obtain a high temperature superconducting magnetic levitation transfer system in which pin stop force acts on the attitude stabilizing section and thereby the truck by a structure wherein the magnetic flux from a permanent magnet group, i.e., a rail, passes through the attitude stabilizing section comprising a superconductor of the second kind which is cooled by means of a cooler to bring about a mixed state of normal conduction and superconduction. CONSTITUTION: Flux from a permanent magnet in a rail 20 passes through attitude stabilizing sections 40a, 40b. Since the attitude stabilizing sections 40a, 40b are cooled by coolers 50a, 50b down to a mixed state, pin stop effect is generated and pin stop force acts on the attitude stabilizing sections 40a, 40b and thereby the truck. Since the pin stop force acts as a guiding force of a truck 10 in Z-direction, attitude of the truck 10 is stabilized even if the truck 10 is subjected to an external force, e.g. centrifugal force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repulsive levitation type high temperature superconducting magnetic levitation transfer device which is widely used in transfer systems in clean rooms.

[0002]

2. Description of the Related Art Conventionally, a repulsive levitation type magnetic levitation transportation device has a basic structure in which a carriage is repulsively levitated by a magnetic force of a permanent magnet laid on a transportation path, while it is conveyed by a propulsive force of a linear motor. There is. However, if a lateral force such as a centrifugal force acts on the truck during transportation, the posture of the truck will become unstable unless there is a special guide, so the guide force control device must be installed to prevent this. It is equipped.
The guide force control device is mounted on the trolley side, detects the posture of the trolley by a sensor, etc., and adjusts the magnitude of the exciting current flowing to the levitation electromagnet based on the detection result, and thereby guides the trolley. Negative feedback control is performed so that the posture is kept constant. However, although some effects can be obtained by devising the arrangement of the permanent magnets laid on the transport path, it cannot be a drastic measure to improve the instability of the posture of the carriage, so even in this case Some kind of stability control device is required.

[0003]

However, in the case of the above-mentioned conventional example, there is a drawback that the structure of the entire apparatus becomes complicated due to the existence of the guide force control apparatus. Further, since the guide force control device has a complicated structure, the failure rate is high, and the weight of the carriage is large, so that there is a drawback that reliability and performance as a magnetic levitation transport device are deteriorated.

The present invention was created in view of the above background, and an object of the present invention is to provide a high temperature superconducting magnetic levitation transfer apparatus which solves the above-mentioned drawbacks.

[0005]

In order to achieve the above-mentioned object, a high temperature superconducting magnetic levitation transporting apparatus of the present invention has a carriage mounted on a rail composed of two rows of permanent magnets arranged in reverse polarities. It has a basic structure for magnetically levitating by using the magnet, is disposed in a position where the magnetic flux emitted from the magnet can pass through even in the carriage, and is stable in posture made of the material of the second type superconductor. And a cooling device that cools the posture stabilizing unit to a temperature required to reach a mixed state. It is preferable that two pairs of rails are laid in parallel at lower positions on both sides of the truck. It is desirable to set the gap between the rail and the carriage so that the change in the density of the magnetic flux generated by the permanent magnets of the rail in the carriage conveying direction becomes small.

[0006]

The magnetic flux emitted from the rail, which is a group of permanent magnets in two rows, passes through the posture stabilizing portion made of the material of the second type superconductor.
Since the posture stabilizing unit is cooled by the cooling device and is in a mixed state in which normal conduction and superconducting are mixed, a pinning effect is produced, and a pinning force acts on the posture stabilizing unit and eventually the carriage. The pinning force also acts as a repulsive magnetic levitation force on the truck.

As shown in FIG. 3, the magnetic flux density due to the permanent magnets of the rail changes greatly in the Z direction (direction orthogonal to the carrying direction), so that the pinning force acts in the Z direction. Since this pinning force acts as a lateral guide force on the carriage, the posture of the carriage is stabilized.

When two sets of rails are laid parallel to each other at lower positions on both sides of the bogie, rolling of the bogie is prevented by the pinning force based on the permanent magnets of the two sets of rails, and the posture of the bogie is more stable.

When the gap between the rail and the carriage is set so that the change in the magnetic flux density generated by the permanent magnets of the rail in the X direction (carriage transport direction) is small, the pinning force in the X direction acting on the carriage is set. It will be small and will not hinder the transportation of the dolly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a high temperature superconducting magnetic levitation carrier device will be described below with reference to the drawings. 1 (a) and 1 (b) are schematic plan views of the device, schematic cross-sectional views taken along the line AA, and FIGS. 2 (a) and 2 (b) are schematics of lines BB and CC of the device. Sectional view, FIG. 3 is a diagram showing the relationship between the magnetic flux density of the rail permanent magnet and the Z-direction displacement, and FIG. 4 is a diagram showing the relationship between the magnetic flux density of the rail permanent magnet and the X-direction displacement. 5 is a diagram for explaining a modified example, a diagram corresponding to FIG. 1 (a), and FIG. 6 is a graph showing the maximum load characteristic of the truck. In addition, the arrow in FIG. 2 has shown the magnetic force line of the permanent magnet of a rail.

The high-temperature superconducting magnetic levitation transfer apparatus described by way of example here is a repulsion levitation type used in a transfer system in a clean room, and has rails laid on the transfer path as shown in FIG. While the carriage 10 is magnetically levitated on the carriage 20, the carriage 10 has a basic configuration in which it is conveyed by the propulsive force of a linear motor (not shown). Note that, as shown in FIG. 1, the carriage direction of the carriage 10 is the X direction, and the lateral direction of the carriage 10 (direction orthogonal to the carriage direction) is the Z direction.

The rails 20 are arranged with the polarities reversed.
It consists of rows of permanent magnets. In this embodiment, Nd-F
eB rare earth permanent magnets are used. Of the two rows of permanent magnet groups, the row with the S pole on the top is shown as a rail 21, and the row with the N pole on the top is shown as a rail 22.

The dolly 10 is provided with a levitation magnet 30 in the center near the center of gravity thereof. In this embodiment, a permanent magnet of the same type as the rail 20 is used as the levitation magnet 30. The magnets corresponding to the rails 21 are shown as levitation magnets 31, and the magnets corresponding to the rails 22 are shown as levitation magnets 32. As shown in FIG. 2A, a repulsive magnetic levitation force acts on the carriage 10 by the permanent magnets of the rails 21 and 22 and the levitation magnet 30. In addition, trolley 1
The object to be transported can be placed on 0, but these are not shown.

In addition to the levitation magnet 30, attitude stabilizing portions 40a and 40b and cooling devices 50a and 50b are provided inside the carriage 10.

The posture stabilizing portion 40a is provided on the X-direction side of the levitation magnet 30 and has a plate-like structure made of the material of the second type superconductor. In this embodiment, a yttrium-based (YBaCuO) material that becomes superconducting at liquid nitrogen temperature is used. However, other materials may be used depending on the type of the cooling medium. The posture stabilizing unit 40a is arranged inside the cooling device 50a.

The cooling device 50a is a container for accommodating the posture stabilizing section 40a together with liquid nitrogen.
It is configured to cool to a temperature necessary to reach the mixed state. The posture stabilizing unit 40a is fixed inside the cooling device 50a.

The cooling device 50a is made of a material having a low non-permeability and a high strength. In this embodiment, a container made of reinforced plastic or the like is used. Therefore, the magnetic flux emitted from the permanent magnets of the rail 20 passes through the posture stabilizing section 40a as shown in FIG. 2 (b), and the pinning force that can be generated at this time is transmitted to the carriage 10 via the posture stabilizing section 40a and the cooling device 50a. Will work.

The posture stabilizing section 40b and the cooling device 50
The description of b is omitted because it is exactly the same as the above.

The operation of the high-temperature superconducting magnetic levitation carrier configured as above will be described. When a linear motor (not shown) is operated, a driving force acts on the carriage 10 that is magnetically levitated by the magnetic force of the rail 20, and along with this,
The carriage 10 moves in the A direction, and the object to be conveyed is conveyed. However, even if a force in the Z direction such as a centrifugal force acts on the carriage during the transportation, the posture of the carriage 10 will not become unstable due to the pinning force described below.

As shown in FIG. 2 (b), the magnetic flux emitted from the permanent magnets of the rail 20 passes through the posture stabilizing portions 40a and 40b. Since the posture stabilizing parts 40a, 40b are cooled to the mixed state by the cooling devices 50a, 50b, a pinning effect is generated here, and a pinning force acts on the posture stabilizing parts 40a, 40b, and eventually the carriage 10. To do. Since the change in the magnetic flux density due to the permanent magnets of the rail 20 is large in the Z direction as shown in FIG. 3, the pinning force acts in the Z direction. Since this pinning force acts as a Z-direction guiding force on the carriage 10, the posture of the carriage 10 is stable even if an external force such as a centrifugal force acts.

However, the pinning force acts not only in the Z direction but also in the X direction, which may hinder the transportation of the carriage 10. In particular, as shown in FIG. 4B, when the change in the magnetic flux density due to the permanent magnets of the rail 20 in the X direction is large, a large pinning force acts on the carriage 10. In such a case, by setting the gap between the rail 20 and the trolley 10 to an appropriate value, the rail 2 can be set as shown in FIG. 4 (a).
The change in the magnetic flux density in the X direction due to the permanent magnet of 0 is made small. The specific value of the gap is rail 20
Although it is determined by the strength of magnetization of the permanent magnets, the total weight of the carriage 10, etc., generally, if the gap between the rail 20 and the carriage 10 becomes large, the magnetic flux density of the permanent magnets of the rail 20 changes in the X direction. Becomes smaller. If the gap between the rail 20 and the truck 10 is set to an appropriate value by such a method, a large pinning force does not act in the X direction, and this does not hinder the transportation of the truck 10.

As described above, when the magnetic flux emitted from the permanent magnets of the rail 20 reaches the posture stabilizing portions 40a and 40b, the guide force in the Z direction acts on the carriage 10, but the repulsive magnetic levitation force also acts. Therefore, if the load of the truck 10 is small, the truck 10 can be levitated without the levitating magnet 30.

This point will be described in more detail. FIG. 6 shows the maximum load characteristics of the bogie 10, and compares the case with the levitation magnet 30 and the case without the levitation magnet 30. The initial gap on the horizontal axis represents the gap between the rail 20 and the carriage 10 without a load, while the maximum load on the vertical axis represents the load on which the carriage 10 can be placed. As can be seen from the figure, there is a difference in the maximum load between when the levitation magnet 30 is provided and when it is not. This is a trolley with a pinning force of 10.
It also means that it also acts as a repulsive magnetic levitation force.

Next, a modification will be described with reference to FIG.
In the case of this modified example, two sets of rails 20 and 20 are laid in parallel at lower positions on both sides of the bogie 10, and two sets of rails 2 are provided.
Corresponding to 0 and 20, the levitation magnet 30 and the posture stabilizing unit 40
Two sets of a and b and cooling devices 50a and 50b are provided. Reference numeral 60 in the figure denotes a linear motor for transporting the carriage 10. Although not shown, the cart 10 is provided with a reaction plate and the like facing the linear motor 60.

According to this modification, the pinning force acts on both sides of the carriage 10 separately, so that rolling of the carriage 10 is prevented and the posture of the carriage 10 becomes more stable. Therefore, it is particularly effective for the truck 10 having a large lateral width in which rolling is likely to occur.

However, even in the case of such a modification, the posture stabilizing portions 40a, 40b and the like may be combined into one set and shared.

[0027]

As described above, in the case of the high temperature superconducting magnetic levitation transport apparatus according to claim 1 of the present invention, the pinning force acts as a lateral guide force on the carriage, so the guide force control device is provided. The posture of the dolly will be stable even if there is not. Considering that it has been indispensable to supply electric power to the truck in the past, the entire configuration becomes extremely simple compared to the conventional one. Along with this, there is an advantage that the failure rate is extremely low and the reliability and performance of the device are improved.

In the case of the high temperature superconducting magnetic levitation carrier according to claim 2 of the present invention, in addition to the structure of claim 1, rolling of the carriage can be prevented, so that the posture of the carriage is more stable. There are merits.

In the case of the high temperature superconducting magnetic levitation transport device according to claim 3 of the present invention, in addition to the configuration of claim 1 or 2, the pinning force acting on the carriage in the transport direction can be reduced. Therefore, there is an advantage that the pinning force does not hinder the transportation of the carriage and contributes to energy saving.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of a high-temperature superconducting magnetic levitation transfer device, wherein (a) and (b) are a schematic plan view of the same device and a schematic cross-sectional view taken along the line AA. .

2 (a) and 2 (b) are schematic cross-sectional views taken along line BB and line CC of the apparatus.

FIG. 3 is a diagram showing the relationship between the magnitude of the magnetic flux density of the permanent magnets on the rail and the displacement in the Z direction.

FIG. 4 is a diagram showing the relationship between the magnitude of the magnetic flux density of the permanent magnets of the rail and the displacement in the X direction.

FIG. 5 is a diagram for explaining a modified example, and FIG.
It is a figure corresponding to.

FIG. 6 is a graph showing a maximum load characteristic of a truck.

[Explanation of symbols]

 10 ... Bogie 20 ... Rail 30 ... Levitation magnet 40 ... Attitude stabilizing unit 50 ... Cooling device

Claims (3)

[Claims] 1. A magnetic levitation transport apparatus configured to magnetically levitate a carriage on a rail composed of two rows of permanent magnets arranged in reverse polarities. However, even the posture stabilizing portion, which is arranged at a position where the magnetic flux emitted from the magnet can pass and is made of the material of the second-class superconductor, and the temperature required to bring the posture stabilizing portion to a mixed state. A high-temperature superconducting magnetic levitation transfer device comprising a cooling device for cooling. 2. The high-temperature superconducting magnetic levitation transfer apparatus according to claim 1, wherein two pairs of the rails of claim 1 are laid in parallel at lower positions on both sides of the bogie of claim 1. 3. The rail and the trolley so as to reduce the change in the magnetic flux density caused by the permanent magnets of the rail in the transport direction in order to reduce the resistance in the transport direction of the trolley of claim 1. The high-temperature superconducting magnetic levitation transport apparatus according to claim 1 or 2, wherein a gap between and is set.