JPH05227608A - Magnetic levitation carrier - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] In magnetic levitation vehicles,
(EN) Provided is a circuit configuration of a simple and highly reliable control system that softens the shock at the time of adsorption. [Structure] A levitation control circuit 4, an adsorption control circuit 7 that performs adsorption control without using this circuit, and a switching circuit 6 that selectively connects these circuits to the levitation magnet 1. When the attraction command is issued, the levitation control circuit 4 is separated from the levitation magnet 1, and the attraction control circuit 7 is connected to the levitation magnet 1. It is not necessary to stop the function of the constant current or constant voltage control circuit in the levitation control circuit at the time of adsorption, and
It is not necessary to add a control signal for soft suction to the gap signal sent from the gap sensor 3, and the soft suction on the rail 2 is performed by a voltage signal of a predetermined pattern output from the suction control circuit 7 via the power amplifier 5. Can be done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic levitation transport vehicle which is capable of reducing an impact when a vehicle body is attracted to a rail with a simple circuit structure.

[0002]

2. Description of the Related Art In a magnetic levitation transport vehicle, the attraction force of a levitation magnet is increased and the magnet is attracted to a rail when an emergency stop or charging is performed. If the adsorption at this time is suddenly performed, a large impact will be generated, and dust, a car body failure,
This will cause damage to the cargo.

Therefore, a technique for softening the adsorption has been developed. As a concrete example, Japanese Patent Application No. 2-20695
As proposed in No. 6, by adding the gap control signal to the gap sensor signal for feedback control before the levitation control circuit and inputting this to the levitation control circuit, the actual gap is more than the set gap. The gap is corrected by the levitation control circuit by making it appear to be slightly larger, and this operation is continued for a certain period of time to advance the suction, or the gap control target value of the levitation control circuit is gradually decreased to soften the suction. There are things to do.

[0004]

In the magnetic levitation transportation vehicle, it is desirable that the required levitation force be satisfied by the attraction force of the permanent magnet as much as possible by using a composite levitation magnet in which a permanent magnet and an electromagnet are combined. This is because the power consumption for levitation is low. Therefore, in this type of transport vehicle, the levitation control circuit keeps the magnet current at the set value by changing the gap between the levitation magnet and the rail. A voltage control circuit is added, and normally, the set value is set to zero so that the current is supplied to the magnet only when the gap is changed or when the gap is changed and a gap other than the standard value is maintained.

However, since the soft adsorption control described above is performed through the levitation control circuit, the functions of these circuits are not stopped in the case where such a constant current or constant voltage control circuit is added. And adsorption control cannot be executed. Therefore, a method is adopted in which a disconnection circuit is inserted in the feedback circuit for the gap sensor signal and the magnet current (or voltage) signal to cut off the constant current of the above signal or the current to the constant voltage circuit during adsorption control.
In this case, it is necessary to insert a separation circuit in all of the levitation magnets and feedback circuits from the gap sensor, which are usually provided four by four, and an addition circuit for soft adsorption control is also required. There was a problem in terms of reliability because the circuit configuration became complicated and the number of failure factors increased.

An object of the present invention is to enable soft suction with a simple circuit in order to improve the reliability of the levitation control circuit.

[0007]

In order to solve the above-mentioned problems, the present invention provides a floating control circuit to which the above-mentioned constant current or constant voltage control circuit is added, and an adsorption control circuit which operates by receiving an adsorption signal. And a switching circuit that disconnects the levitation control circuit from the levitation magnet in response to the attraction signal and connects the attraction control circuit to the levitation magnet. The attraction control circuit connected during attraction directs the magnet to the levitation magnet. Adopting a device configuration that outputs a voltage signal of a predetermined pan for attracting to the rail.

[0008]

[Function] By providing a switching circuit and separating the levitation control circuit from the levitation magnet at the time of adsorption, it is not necessary to stop the function of the constant current or constant voltage control circuit in the levitation control circuit, and the feedback signal separation circuit, etc. It becomes unnecessary. Also,
Since the suction control is not performed through the levitation control circuit, soft suction can be performed by sending a signal of a predetermined pattern from the suction control circuit without using an adder for the gap control signal or a circuit for reducing the target control value of the gap.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the magnetic levitation transport vehicle of the present invention.

FIG. 1 shows a levitation magnet which is attracted to a ferromagnetic rail 2. This magnet is a composite magnet in which a permanent magnet is attached to the magnetic pole surface of an electromagnet, and one magnet is provided at each of the four corners of the upper part of the vehicle body. A gap sensor 3 is provided on the vehicle body side in the vicinity of each levitation magnet, detects a gap between the rail 2 and the magnet 1, and outputs a signal proportional to the size of the gap to the levitation control circuit 4. .. The levitation control circuit 4 is provided with the above-mentioned constant current or constant voltage control circuit, and here, the levitation control circuit 4 is used to keep the energization current of the magnet at zero when the predetermined gap is maintained. Although not shown in the figure, the detection signal of the magnet current (or voltage) is also fed back to the levitation control circuit 4.

In the figure, 5 is a power amplifier, 6 is a switching circuit, and 7 is an adsorption control circuit. When the switching circuit 6 receives the attraction command and switches, the output of the attraction control circuit 7 is proportionally amplified by the power amplifier 5 and applied to the levitation magnet 1. The adsorption control circuit 7 has a computer 8 and D / A converters 9 as many as the number of magnets, and a voltage signal pattern for soft adsorption is previously input and stored in the computer 8. The pattern signal is output via the D / A converter 9 in response to the attraction command, and simultaneously passes through the circuit 6 that has been switched, and further passes through the power amplifier 5 to the levitation magnet to perform the attraction operation.

FIG. 2 shows an example of the adsorption signal pattern stored in the computer 8. As described above, the levitation control is performed so that the energizing current of the levitation magnet becomes zero during stationary levitation in which a predetermined gap is maintained. That is, when the energizing current is zero, the attraction force 4F ₀ of the four permanent magnets and the load W of the transport vehicle are balanced at a position where a certain gap is maintained, and the transport vehicle is supported only by the attraction force of the permanent magnets. Therefore, assuming that the gap in this state is 3 mm from the attraction characteristic of the permanent magnet shown in FIG. 3, FIG. 4 shows the attraction force characteristic of the composite levitation magnet when the gap is 3 mm. As can be seen, when the current of the electromagnet of the levitation magnet is gradually increased from the state of zero current, the attractive force F of the levitation magnet increases, the balance between the load and the attractive force is lost, and the levitation magnet moves to the rail. It is pulled in the direction of adsorption. Further, as a result, the gap between the rail and the levitation magnet becomes smaller, so that the attractive force of the permanent magnet increases at an accelerating rate.

Therefore, the purpose of soft attraction cannot be achieved by simply passing a current in the direction of increasing the attractive force to the magnet from the state where the magnet current is zero. Therefore, the attraction signal of FIG. 2 is a pattern in which the attraction force increase of the permanent magnet due to the gap reduction is subtracted and the attraction force slightly larger than the weight of the transport vehicle is maintained from the attraction start time to the attraction end time. I am doing it. According to this signal pattern, after the adsorption command is input, a current in the plus direction that strengthens the attraction force momentarily flows to the electromagnet and the adsorption is started. After that, the current in the positive direction is sharply reduced and the current in the negative direction is flown out to cancel the attraction force of the permanent magnet, so the increase in the attraction force of the permanent magnet due to the gap reduction is offset, and the attraction force is slightly larger than the load. The soft adsorption at will be executed.

FIG. 5 shows another embodiment of the adsorption control circuit 7. As described above, soft adsorption can be performed by using the CR time constant circuit 10 instead of the computer and the D / A converter shown in FIG. Reference numeral 11 is a delay circuit that delays the adsorption command and sends it to the CR time constant circuit. For example, when the attraction start timing of the two magnets at the rear of the vehicle body is delayed by using this delay circuit 11, the magnet at the front of the vehicle body is slowly attracted first, and then the magnet at the rear portion of the vehicle body is slowly attracted, so that soft attraction is performed. Will be more effective.

When the floating command is received, the switching circuit 6 returns to the state shown in the figure.

[0016]

As described above, according to the present invention,
Since the switching circuit is used to selectively switch the connection state of the levitation control circuit and the suction control circuit to the levitation magnet, the purpose of soft attraction can be achieved without complicating the circuit configuration and the reliability of the control system. There is an effect that the cost can be improved because the cost can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a suction signal pattern.

FIG. 3 is a diagram showing attraction force characteristics of a permanent magnet.

FIG. 4 is a diagram showing attraction force characteristics under a constant gap of a composite levitation magnet.

FIG. 5 is a diagram showing an outline of another embodiment of the present invention.

[Explanation of symbols]

 1 levitation magnet 2 rail 3 gap sensor 4 levitation control circuit 5 power amplifier 6 switching circuit 7 adsorption control circuit 8 computer 9 D / A converter 10 CR time constant circuit 11 delay circuit

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Claims (1)

[Claims] 1. A levitation control circuit to which a constant current or constant voltage control circuit is added for keeping the current or voltage of the magnet at a set value by changing the gap between the levitation magnet and the rail, and actuated by receiving an adsorption signal. And a switching circuit for disconnecting the levitation control circuit from the levitation magnet in response to the attraction signal and connecting the sorption control circuit to the levitation magnet.The attraction control circuit directs the levitation magnet. A magnetic levitation transport vehicle that outputs a voltage signal of a predetermined pattern that gradually attracts the magnet to the rail.