JPS62275926A - System for controlling magnetically levitating slider - Google Patents

Abstract

PURPOSE:To ensure a necessary gap by overlapping magnetic fluxes of an electromagnet and a permanent magnet when a magnetically levitating system of zero power one needs a static load by which the gap between the permanent magnet and a rail is mode smaller than a limited one. CONSTITUTION:A leg block 30 of a guide rail 20 is fixed on a base 10 and a stator 23 of an induction type linear motor is disposed on the central portion of the guide rail 20. On the other hand, a slider 40 has vertical plates 41, 42 on both sides of guide rail 20 and horizontal plates 43, 44 and 45, 46 extending inward from the upper and lower portions of said vertical plates. The horizontal plates 45, 46 are provided with a permanent magnet 63 constituting magnets 60, 60 for a magnetic bearing, cores 61, 62 and coils 65, 64. The magnet 60 for magnetic bearing is provided with a position sensor 1 to detect a gap between the upper surface 66 of an electromagnet and a guide surface 67 at the underside of guide rail 20. When a static load is needed which narrows the gap by a predetermined value or more, current is supplied to the coils 65, 64 to produce magnetic fluxes laid on those of the magnet 63. Thus, a necessary gap is held to prevent the magnet from contact with the rail.

Description

[Detailed description of the invention] 3. Detailed description of the invention Corporate soil - dust and dirt field The present invention relates to a control method for a magnetically levitated slider.

In order to maintain the power consumption of the conventional control type magnetic bearing, an electromagnet and a permanent magnet are used together, and the permanent magnet takes charge of the static load. This is done by force control, and static load fluctuations are achieved using the so-called zero-power magnetic method, which takes advantage of the fact that the attraction force increases as the gap between the permanent magnet and the rail becomes smaller, and balances the attraction force by changing the gap. Bearings are used in spindles for space equipment, etc.

It is easy to apply the above method to a magnetically levitated slider. However, with this method, for example, when a large static load is applied, the gap between the magnet and the rail becomes too small.
When traveling, there is a risk that the magnet may come into contact with the rail due to poor machining accuracy of the rail.

Also, the relationship between the gap p between the magnets and the attractive force F is F=/β
It changes with When the base 4S gap is p, the amount of change Δp in the suction force due to each change in the gap Δρ is expressed by the following equation.

If p is large enough for Δρ, the second term in equation 0 can be ignored, but as p becomes smaller, the influence of the second term increases, and a small change in the gap will cause a large change in the suction force. , the disadvantage is that the control system tends to become unstable.

The control system for the magnetically levitated slider of the present invention consists of a position sensor, an electromagnet, and a permanent magnet, and the static load is borne by the attractive force of the permanent magnet. In a control method for a magnetically levitated slider using zero-power magnetic levitation, which holds the load by controlling the electromagnetic force of an electromagnet, changes in the gap between the permanent magnet and the rail generate an attractive force that balances the static load. For static loads that require a limited range and an attractive force that exceeds this gap range, the magnetic flux of the electromagnet is added to the magnetic flux of the permanent magnet to control the attractive force, and the static load increases. 1.The structure is such that the permanent magnet does not approach the rail beyond a certain gap.

1. Since Rimiku limits the output of the integral element, FIiIQ, the permanent magnet does not approach the rail beyond a certain gap.

Accordingly, FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a sectional view in the direction of movement of the magnetic #-1 slider, and FIG.
Each figure shows a circuit diagram of the zero power system of the present invention, which includes a limiter and an integral element.

In FIG. 1, A is an adder, and a position setting voltage is applied to this adder A. A phase compensation circuit B stabilizes this feedback system and compensates the output of the adder A to obtain the necessary frequency characteristics. The output of the phase compensation circuit B is power amplified by the voltage and current of the next stage and the power amplification amount 1i4%c, and is positive-feedbacked to the adder A via the 81-minute element E and the limiter 4.
It is input to a power/force converter consisting of an electromagnet. The output converted into force by the power/force converter acts on the control object G, so that the displacement is expressed as η. As shown in FIG. 3, the Rimiku J is specifically composed of Zener diodes A and B connected in parallel with each other in opposite phases. The Zener diode serves as a limiter for either A or B depending on the polarity of the integral element output when the rail and magnet are close to each other.
If both are provided, there is no need to recognize the polarity.As the gap becomes smaller, an electromagnet will add an attractive force, which acts as an element that destabilizes the control system. This is a loop of the gap characteristic H of the magnet that is positively fed back to the addition point F from the displacement output in FIG.

The displacement output is negatively fed back to the adder A via the displacement voltage converter I.

In FIG. 2, a guide rail 20
A leg block 30 is fixed, and a stator 23 of an induction linear motor is arranged at the center of the guide rail 20.

On the other hand, the slider 40 includes vertical plates 41.42 arranged on both sides of the guide rail 20, an upper horizontal plate 43.44 and a lower horizontal plate 45.46 extending from above and below the vertical plate 41.42 to the guide rail 20. It is equipped with And stator 23
The upper horizontal plates 43, 44 are connected to each other by a secondary conductor 47 which faces the stator 23 and constitutes the linear motor. The upper surface of the secondary conductor 47 is covered with a bullet 49 while maintaining a gap 48, and a plurality of electric circuit boards 50 are arranged in the gap 48.

Magnetic bearing magnets 60 and 60 are provided on both sides of the lower horizontal plate 45 and 46 of the slider 40. This magnetic bearing magnet 60 is composed of a permanent magnet 63, a core 61.62 made of soft magnetic material sandwiching the permanent magnet 63, and wires 65 and 64 that wind the core 61.62. . As shown in the figure, the magnetic bearing magnets 60 and 60 are provided with the position sensor [1].
, ■ detects the gap between the upper surface 66 of the electromagnet and the lower surface of the guide rail 20, that is, the guide surface 67.

The control system of the slider consists of a position sensor, an electromagnet, and a permanent magnet, and the static load is handled by the attractive force of the permanent magnet.The dynamic load is handled by the electromagnetic force of the electromagnet. In the control method of a magnetically levitated slider that uses a V-ropower one-way magnetic levitation system that controls force and holds the load,
The range of change in the gap between the permanent magnet and the rail that generates an attractive force that balances the static load is limited, and the attractive force that exceeds this gap range is limited. The magnetic flux is added to the magnetic flux to control the attractive force, and the static load is increased so that the permanent magnet does not approach the rail beyond a certain gap.

Therefore, even when a large static load is applied, for example, the necessary clearance is ensured, and there is no risk of the magnet coming into contact with the rail due to vibrations during running or machining accuracy in the system configuration, etc. A stable control system can be achieved.

[Brief explanation of the drawing]

FIG. 1 shows a block diagram of an embodiment of the present invention, FIG. 2 shows a sectional view in the direction of movement of a magnetically levitated slider, and FIG. 3 shows a circuit diagram of the main parts of the invention. A... Adder, B... Phase compensation circuit, C... Voltage current and power amplifier circuit, D... Power/force converter, E
... Integral element, F... Addition point, G... Control symmetry,
11...Gap characteristics, ■...Displacement voltage converter (position sensor), J...Limiter-0 Patent applicant NCH Nis Toyo Hairing Co., Ltd.

Claims (1)

[Claims] (1) Utilizes zero-power magnetic levitation, which consists of a position sensor, an electromagnet, and a permanent magnet, and uses the static load by the attraction force of the permanent magnet, and the dynamic load by controlling the electromagnetic force of the electromagnet to hold the load. In the control method of the magnetically levitated slider, the range of change in the gap between the permanent magnet and the rail that generates an attractive force that balances the static load is limited, and for static loads that require an attractive force that exceeds this gap range, A magnetically levitated slider characterized by being equipped with a mechanism that controls the attractive force by adding the magnetic flux of the electromagnet to the magnetic flux of the permanent magnet, and prevents the permanent magnet from approaching the rail beyond a certain gap in response to an increase in static load. control method.