JPH04349606A - Superconducting magnet for magnetically floating movable structure - Google Patents

Abstract

PURPOSE:To prevent a superconducting state from being destroyed owing to the temperature rise of a superconducting magnet for a magnetically floating train. CONSTITUTION:There is provided on the surface of an outer tank 1 a member having a function to prevent any vibration, whereby any vibration produced on the outer tank 1 is prevented from being transmitted to a superconducting magnet 8. A vibration prevention mechanism is constructed by: 1' disposing at least one or more of friction production structures 2, 3, and connecting to the outer tank 1 through a bolt 5 or welding keeping a gap; 2' inserting a vibration damping member 6 between the outer tank 1 and the fabrication production structure 2; 3' applying a paint 7 involving metal particles blended therein between the outer tank 1 and the friction production structure 2; or 4' disposing a mass-spring system 11 on the surface of the outer tank 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping structure for superconducting magnets for magnetically levitated trains.

0002

2. Description of the Related Art Conventional vibration-proof structures for magnetically levitated trains have been proposed, for example in Japanese Patent Laid-Open No. 77309/1989, which reduce vibrations generated in the train in order to improve riding comfort. , no consideration is given to reducing vibration in the superconducting magnet support structure itself. However, it is essential to consider reducing the vibration of superconducting magnets for the following reasons.

As shown in FIG. 15, a magnetically levitated train has a superconducting magnet 8 on a car body 15, and is propelled and levitated by a propulsion coil 17 and a levitation coil 18 provided on the ground. This principle will be briefly explained.

Magnetic levitation trains are propelled by the principle of linear synchronous motors. That is, for example, when the vehicle body is in the position A in FIG. 17, a current is caused to flow through the propulsion coil 17 on the ground in the direction of the solid arrow. At this time, the vehicle body 15 is propelled by a force in the direction of the arrow in this figure according to Fleming's left-hand rule.

Next, when the vehicle body 15 comes to position B, a current is applied in the direction of the broken line. In other words, for the middle coil in this figure, the direction in which the current flows is switched. Then, the vehicle body 15 receives a force in the direction of the arrow in this figure and moves in the same direction. This repetition allows the vehicle to continue moving in the same direction. This is the driving principle.

Next, the principle of levitation will be explained. When the car body runs according to the principle described here, the levitation coil 1 installed on the ground
8, an induced current is generated. The induced current flows in a direction that cancels the magnetic field created by the superconducting magnet 8 attached to the vehicle body 15. This generates a magnetic repulsion force that causes the vehicle to levitate. This is the principle of levitation.

[0007] As described above, a superconducting magnetically levitated train levitates due to the magnetic force generated by a ground coil installed on the ground and a superconducting magnet. Since the north and south poles of the ground coil alternate, the superconducting magnet moving on the ground coil receives a fluctuating magnetic field caused by the switching between the north and south poles.

[0008] Therefore, a secondary current is induced in the outer tank housing the superconducting magnet. This induced current and the magnetic field of the superconducting magnet generate electromagnetic force according to Fleming's law. This electromagnetic force causes vibrations in the superconducting magnet.

[0009] Since superconducting magnets need to be kept at extremely low temperatures (absolutely 4 degrees Celsius), it is important to suppress vibrations that can cause heat generation and the like. Therefore, it is necessary to provide a low-vibration structure for the superconducting magnet structure itself in a superconducting magnetic levitation train.

0010

[Problems to be Solved by the Invention] However, until now, there have been few inventions that have considered anti-vibration measures for superconducting magnets themselves, and measures to reduce vibration have not necessarily been sufficient. In particular, trains often travel at a constant speed, but when they travel at a constant speed, they receive an electromagnetic excitation force whose basic frequency is determined by the traveling speed and the ground contact interval of the levitation coil on the ground. become.

Furthermore, since the ground coils are installed discretely at equal intervals, they vibrate in a complex manner due to the frequencies of their harmonic components in addition to the above-mentioned fundamental frequency. Therefore, it is necessary to consider a mechanism to reduce vibrations while running at a constant speed.

An object of the present invention is to provide a means for avoiding resonance of the superconducting magnets and preventing heat generation, etc. of the superconducting magnets when a magnetically levitated train using superconducting magnets continues to receive electromagnetic excitation force while running and vibrates greatly. It is about giving.

[0013]

[Means for Solving the Problems] In order to achieve the above object, at least one friction generating body is arranged on the surface of the outer tank of a superconducting magnet, and when the outer tank is not vibrating, the friction generators are in light contact with each other. Or install it with a slight gap. When the outer tank vibrates and deforms when it is attached in this manner, the friction generating bodies rub against each other and friction occurs. Vibration energy is consumed as heat due to friction, and vibrations are damped.

[0014] A vibration damping material is inserted between the friction generating body and the surface of the outer tank, and when the outer tank vibrates and deforms, a relative shift is generated between the friction generating body and the outer tank to damp the vibration. It is also possible to generate strain in the material and cause internal friction due to the strain inside the damping material.

[0015] In another embodiment, a paint containing minute particles of non-magnetic metal is applied to the surface of the outer tank so that when the outer tank vibrates, friction is generated between the metal particles and the paint. Alternatively, it is also effective to provide a structure in which at least one mass-spring system is attached to the surface of the outer tank to generate vibrations in the opposite phase to the vibrations of the outer tank to cancel out the vibrations of the outer tank.

[0016] Magnetic materials cannot be used in the friction generator used in the present invention. This is because the friction generating body remains attracted to the surface of the outer tank due to the strong magnetic force of the superconducting magnet, so that even if the outer tank vibrates, no relative displacement occurs between the outer tank and the friction generating body. Therefore, as friction generating bodies, non-magnetic metal plates such as aluminum and stainless steel, FRP, etc.
A resin plate such as is preferable.

[0017]

[Operation] In this invention, when the outer tank is vibrated and deformed by electromagnetic force, the friction generating bodies come into contact with each other and rub against each other. The friction generated at this time converts the vibrational energy of the outer tank into thermal energy and dissipates it, dampening the vibrations.

[0018] When a damping material is inserted between the friction generator and the outer tank surface, when the outer tank vibrates and deforms, a relative displacement occurs between the friction generator and the outer tank. Distortion occurs in the damping material. Inside the damping material, strain causes friction between the damping material particles, and the friction converts vibrational energy into thermal energy, damping vibrations.

When a paint containing minute particles of non-magnetic metal is applied to the surface of the outer tank, when the outer tank vibrates, friction occurs between the mixed metal particles and the paint, and this friction generates vibration energy. is converted into thermal energy and reduces vibration.

Furthermore, when the natural frequency of the mass-spring system is made to match the frequency of the outer tank, the mass-spring system vibrates in the opposite direction to the vibration direction of the outer tank, and operates to suppress the vibration of the outer tank. do.

[0021]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the invention. A bogie underframe 16 is provided at the bottom of a car body 15 of a magnetically levitated train, and a load supporting structure is attached to this. The bogies of magnetic levitation trains are equipped with superconducting magnets that generate the power to levitate the train and drive it at high speed.

[0022] A propulsion coil 17 and a levitation coil 18 are arranged at a distance from each other on opposite sides of this load supporting structure. These coils are formed on the track side.

[0023] The superconducting magnet has an outer tank 1 in the part that comes into contact with the outside air,
A shield plate 9 that is located between the superconducting magnet 8 and the outer tank 1 and blocks radiant heat from the outside, and a load support 1 that supports the load.
Consists of 0.

A mounting board 4 for mounting the friction generators 2 and 3 is fixed to the outer surface of the outer tank 1. The friction generators 2 and 3 are fitted onto the mounting board 4 with bolts 5.

Both ends of the friction generators 2 and 3 are inclined at an angle θ, and the inclined portions of both ends overlap each other.

[0026] The contact area at both ends is made as large as possible,
Moreover, in order to increase the contact rigidity, the angle θ must be 15~
45 degrees is appropriate. Further, in order to avoid the gap δ between the bolt 5 and the friction generators 2 and 3 being too large and causing no contact, it is appropriate that the gap δ is 0.3 mm or less.

When the outer tank 1 vibrates, the friction generators 2 and 3 rub against each other at both ends, causing friction. This friction converts vibrational energy into thermal energy and absorbs vibrations. By changing the materials of the friction generators 2 and 3, the noise generated by friction can be reduced.

FIG. 2 shows an embodiment in which the friction generator 2 and the friction generator 3 are attached to a mounting substrate 4 by welding. In this case, a slight gap is left between the friction generator 2 and the friction generator 3.

FIG. 3 shows an embodiment in which the friction generators 2 and 3 are attached to the outer tank 1 without using the mounting board 4. Since the inside of the outer tank 1 is in a vacuum, the screw bolt 5 needs to stop midway through the thickness of the outer tank 1.

FIG. 4 shows a trapezoidal projection provided on the surface of the outer tank 1.
This is an embodiment in which a friction generating body 2 is disposed between the protrusions.

FIG. 5 shows an embodiment in which a plurality of trapezoidal projections are provided on the friction generating body 2 and are fitted into trapezoidal projections provided on the surface of the outer tank 1.

FIG. 6 shows an embodiment in which the friction generator 2 is embedded in a groove provided on the surface of the outer tank 1.

FIG. 7 shows an embodiment in which a damping material 6 is inserted between the friction generating body 2 and the outer tank 1. Adhesive is used as the vibration damping material 6, and the viscous damping effect of the adhesive is utilized. For stable adhesion, the thickness of the adhesive layer must be 0.05 mm or more.

When the outer tank 1 vibrates, the friction generator 2 and the outer tank 1
A relative displacement occurs during this time, and shear strain is applied to the adhesive. When strain is applied to the adhesive, friction occurs inside the adhesive, which absorbs vibrational energy as frictional heat.

FIG. 8 shows the friction generating body 2 shown in the embodiment of FIG.
This is an embodiment in which a damping material 6 is inserted between the outer tank 1 and the outer tank 1.

FIG. 9 shows the friction generating body 2 shown in the embodiment of FIG.
This is an embodiment in which a damping material 6 is inserted between 3 and the outer tank 1.

FIG. 10 shows an embodiment in which the surface of the outer tank 1 is coated with a damping paint 7 containing metal particles such as lead. The thickness of the coating layer is greater than or equal to the thickness of the outer tank 1. When the outer tank 1 vibrates, friction occurs between the metal particles and the paint inside the paint, and the vibration energy is absorbed as frictional heat.

Although the vibrations of the outer tank caused by electromagnetic force can be considerably reduced by the embodiments shown in FIGS. 1 to 10, in some cases the vibrations cannot be reduced sufficiently. In such a case, the frequency of the outer tank should be f (Hz)
If the mass 11 of the mass-spring system is m and the spring constant is k, then the natural frequency f0 of the mass-spring system is f0 = (1/
2π)√(k/m).

If the mass m and spring constant k are set so that f0=f, the mass-spring system will vibrate in the opposite direction to the vibration direction of the outer tank, and the inertia will be in the direction of suppressing the vibration of the outer tank 1. The force is applied, and the vibration of the outer tank 1 is reduced.

The mass-spring system should be installed at a location where the vibration of the outer tank 1 is large, that is, at or near the antinode of the vibration. There are usually one or more antinodes of vibration in the outer tank 1, and one or more mass-spring systems are also required.

FIG. 11 shows an example of a mass-spring system using a vibration isolating rubber 12, FIG. 12 shows an example of a mass-spring system using a cantilever plate spring 14, and FIG. 13 shows a mass-spring system using a coil spring 13. - Example used in a spring system FIG. 14 is an example of a mass-spring system using a plate spring 14 supported on both sides.

[0042]

[Effects of the Invention] According to the present invention, since the vibration damping ability of the surface of the outer tank is improved, it is possible to reduce the increase in vibration amplitude caused by the vibration of the outer tank due to electromagnetic force, and the vibrations are quickly reduced. Attenuates the transmission of vibrations to the superconducting magnet. This has the effect of reducing the phenomenon in which the superconducting magnet generates heat due to vibration, the temperature rises, and the superconducting phenomenon is destroyed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 7 is a partial cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 8 is a partial cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 9 is a partial cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 10 is a partial cross-sectional view of a superconducting magnet for a magnetically levitated moving body according to an embodiment of the present invention.

FIG. 11 is a schematic cross-sectional view of essential parts showing an embodiment of the mass-spring system of the present invention.

FIG. 12 is a schematic cross-sectional view of essential parts showing an embodiment of the mass-spring system of the present invention.

FIG. 13 is a schematic cross-sectional view of essential parts showing an embodiment of the mass-spring system of the present invention.

FIG. 14 is a schematic cross-sectional view of essential parts showing an embodiment of the mass-spring system of the present invention.

FIG. 15 is an explanatory cross-sectional view of the main part of the magnetic levitation train.

FIG. 16 is a side view of the main part of the magnetic levitation train.

FIG. 17 is an explanatory diagram showing the principle of levitation of a magnetically levitated train.

FIG. 18 is an explanatory diagram showing the principle of levitation of a magnetically levitated train.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Outer tank, 2... Friction generator, 3... Friction generator, 4... Mounting board, 5... Bolt, 6... Damping material, 7... Damping paint, 8... Superconducting magnet, 11... Mass, 12... Prevention Swing rubber, 13...coil spring, 14...plate spring.

Claims (8)

[Claims] 1. A superconducting magnet for a magnetically levitated vehicle, comprising an outer tank for accommodating at least a superconductor and a load support, characterized in that the outer tank is provided with a magnet having a function of suppressing vibrations. Superconducting magnet for levitated moving objects. 2. A superconducting magnet for a magnetically levitated moving body, wherein the magnet having the function of suppressing vibration according to claim 1 has at least one friction generating body provided in the outer tank. [Claim 3] The friction generating body according to Claim 2 has a thickness of 0.3 mm.
A superconducting magnet for a magnetically levitated vehicle, characterized in that it is attached to the surface of an outer tank or a substrate so that it can move within the following range. 4. The device having the function of suppressing vibrations according to claim 2 is provided with a protrusion or groove on the outer tank, and a friction generating body that follows the shape of the protrusion or groove is disposed in the protrusion or groove. A superconducting magnet for magnetically levitated moving objects. 5. A magnetically levitated moving body according to claim 2, 3 or 4, wherein the friction generating body is a non-magnetic metal plate or a resin plate, and the inclination angle of both ends thereof is 15 to 45 degrees. superconducting magnets. 6. A superconducting magnet for a magnetically levitated moving body having the function of suppressing vibration according to claim 1, wherein a damping material is inserted between the friction generating body and the outer tank. . 7. A superconducting magnet for a magnetically levitated moving body, wherein the magnet having the function of suppressing vibration according to claim 1 has an outer tank coated with a paint having vibration suppressing properties. 8. A superconducting magnet for a magnetically levitated moving body, wherein the magnet having the function of suppressing vibration according to claim 1 is provided with a dynamic damper comprising a mass and a spring attached to the outer tank.