JPH082129B2 - Suction type magnetic levitation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a suction type magnetic levitation device that constitutes a levitation control system of a magnetic levitation transportation means.

[Conventional technology]

FIG. 2 shows the configuration and operating principle of a conventional attraction type magnetic levitation device that uses both a permanent magnet and an electromagnet.

This device comprises a ferromagnetic track 1, an electromagnet 2 composed of a U-shaped iron core 2a and a coil 2b wound around it, and a permanent magnet 3 fixed to the upper end of the iron core. The levitation is mainly performed by the attractive force of the permanent magnet 3, and the levitation amount is adjusted by the variable attractive force of the electromagnet 2.

However, with such a configuration, the coil of the electromagnet
No matter whether the current flowing through 2b is changed to positive or negative, only a suction force for lifting the vehicle body upward can be generated. This is because when the gear gap G between the track 1 and the permanent magnet 3 is constant, the attractive force is proportional to the square of the magnetic flux density in the gear gap.
That is, assuming that the gear-up magnetic flux density of the permanent magnet 3 is Bo and the gear-up magnetic flux density of the electromagnet 2 is b, the attractive force F generated by the device shown in the figure is represented by F∝ (Bo ± b) ² ≧ 0. Therefore, no matter how the current i (∝b) flowing through the coil 2b is controlled, only the attractive force can be generated, the area of the levitation control that can be performed stably is narrowed, and the control response is also limited. I cannot avoid it.

Therefore, the technique disclosed in Japanese Utility Model Laid-Open No. 60-117601 has been proposed. This is because a permanent magnet that exerts an attractive force on the lower surface of the magnetic rail and two electromagnets that face each other are provided on the upper and lower surfaces of the rail, and the attractive force of the permanent magnet cancels the gravity applied to the vehicle and the bogie. The flying height is controlled by an electromagnet.

[Problems to be Solved by the Invention]

According to the technique disclosed in the above publication, the problems found in the levitation apparatus of FIG. 2 are eliminated, and the power required for levitation control is also reduced. However, the technique of this publication requires an electromagnet and a control device for guidance control.

For example, many small magnetic levitation vehicles that carry articles do not require strict guidance control, unlike a person transport vehicle, and in such cases it is not advisable to add cost to the guidance device. In this regard, the technique disclosed in the above publication has a problem that the device cost is high because the guide electromagnet and the control device are provided, and the operating cost is increased due to the power consumption in the guide control.

The present invention is a suction type magnetic levitation device proposed as a solution to such a problem.

[Means for solving the problem]

In order to eliminate the above-mentioned problems, the present invention has a leg portion on both sides, and one side portion side of the rail is provided above and below a ferromagnetic rail having an H-shaped cross section that exerts an attractive force on the upper and lower surfaces of the leg portion. A pair of electromagnets connected to each other are arranged to face each other, and the upper and lower electromagnets have magnetic pole surfaces at both ends of an iron core projecting toward the rail side and facing the upper and lower surfaces of the leg portion. On each magnetic pole surface of the electromagnet, the total attractive force of the two when the width of each is almost equal to the width of the leg and the gap between the upper and lower electromagnets with respect to the rail is kept at a standard value. Attach a permanent magnet that equals the burdened weight integrally, and further,
The upper and lower electromagnet coils are connected in series or in parallel to form a levitation device.

In this way, the coil current can be adjusted to be positive or negative to generate not only an upward force but also a downward force, as will be described in detail later, and the control region is expanded.

Also, the width of the permanent magnet is almost equal to the width of the leg of the rail, and when the electromagnet laterally shifts with respect to the rail, the permanent magnet also shifts from the leg, and this magnet automatically shifts laterally in an attempt to maintain the original relationship due to the attractive force. Is fixed. Therefore, the guide electromagnet is not required.

〔Example〕

The levitation device 10 shown in FIG. 1 includes a ferromagnetic rail 11 (a rail cross section is H-shaped as shown in the figure), electromagnets 12 and 13 arranged to face each other vertically, and an iron core of a lower electromagnet 12. The permanent magnet 14 fixed on the 12a with the polarity shown in the figure, and the connecting member 15 for mechanically connecting the iron cores 12a, 13a of the pair of electromagnets 12, 13 on the side of one side of the rail are constituent elements, and A pair of electromagnet coils 12b and 13b are connected in series.

The coils 12b and 13b may be connected in parallel, but the permanent magnet 14 has a suction force equal to the burden weight when the gears G ₁ and G ₂ of each electromagnet with respect to the rail 11 have a standard gearup value. Must be adjusted accordingly. Further, the permanent magnets 14 mounted on the magnetic pole surfaces at both ends of the iron core 12a are set to have a width substantially equal to the width of the legs on both sides of the rail for exerting an attractive force, as shown in the figure.

Next, regarding the operation during operation, under the standard gear, the magnetic flux density in the gear G ₁ by the permanent magnet 14 is
o, the magnetic flux density in the gear G ₁ due to the lower electromagnet 12 is b ₁ ,
If the magnetic flux density in the gear G ₂ by the upper electromagnet 13 is b ₂ , then the attractive force F for levitation is F∝ (Bo ± b ₁ ) ² −b ₂ ² = Bo ² ± 2b ₁ · Bo + b ₁ ² −b It is shown by the formula of ₂ ² . Here, assuming that | b ₁ | = | b ₂ | for the simplification of the formula, F ∝Bo ² ± 2b ₁ · Bo Therefore, by changing the positive / negative of the current, the following formula, that is, b ₁ > Bo / When the control satisfying the expression (2) is performed, F becomes a negative force, that is, a downward force, and the levitation control region is expanded compared with the conventional case. Also,
Therefore, the control response is also improved.

Further, when the electromagnet is laterally displaced with respect to the rail, the displacement is corrected by the attractive force of the permanent magnet, so that a special guide control system is unnecessary.

〔effect〕

As described above, according to the present invention, the pair of electromagnets mechanically connected to each other are arranged above and below the ferromagnetic orbit, and the coils of the magnets are connected in series or in parallel and located below the orbit. A permanent magnet is installed on the upper surface of the iron core of the lower electromagnet to balance the attractive force with the weight of the standard gear when it is loaded, so that the current can be adjusted to positive or negative to apply a bidirectional force to the vehicle body. The stable region is widened and the control response is improved. In addition, the width of the permanent magnet is made almost equal to the width of the leg of the rail, and the lateral displacement is automatically corrected by the attractive force of the permanent magnet. Power consumption is also gone.

Also, two electromagnets are required, but the driving power supply, control circuit, and sensors such as the gearup detector need only be one set, so the economic burden is not so strong and the levitation force during standard gearup is Since the permanent magnet bears the burden, it consumes less power during operation.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the device of the present invention as seen from the end face side of a track, and FIG. 2 is a diagram showing a conventional attraction type magnetic levitation device. 10 …… Levitation device, 11 …… Ferromagnetic rail, 12, 13 …… Electromagnet, 12a, 13a …… Iron core, 12b, 13b …… Coil, 14 ……
Permanent magnet, 15 ... Connecting member

Claims (1)

[Claims] 1. A ferromagnetic rail having H-shaped cross sections, which has legs on both sides and exerts an attractive force on the upper and lower surfaces of the legs,
A pair of electromagnets that are connected to each other on one side of the rail are arranged to face each other, and the upper and lower electromagnets have magnetic pole surfaces at both ends of an iron core projecting toward the rail side and are attached to the upper and lower surfaces of the leg portion. When facing each other, the width of each of the lower electromagnets is approximately equal to the width of the leg, and the gap between the upper and lower electromagnets is kept at a standard value with respect to the rail. An attraction type magnetic levitation device in which permanent magnets whose total attraction force is equal to the burden weight are integrally attached, and coils of upper and lower electromagnets are connected in series or in parallel.