JPS6032581A - Magnetically levitating linear guide - Google Patents

Abstract

PURPOSE:To obtain stable levitating state by modulating the magnetic flux of a permanent magnet by the magnet of an electromagnet, thereby maintaining the gap constant. CONSTITUTION:Even if a variation occurs in a gap 23a, magnetically attracting force is controlled by modulating in gaps 23b, 23c in the magnetic flux 25 of an electromagnet formed of a yoke 21b and a coil 22a by permanent magnets 20a, 20b, thereby maintaining the gaps 23a-23d constant. Thus, the weight of the movable element can be supported by the attracting force of the permanent magnet, thereby obtaining stable levitating state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic levitation guide that supports a movable body against a fixed part in a non-contact state by magnetic force.

[Prior art]

Accordingly, it is common for the inside of the electric pipe to have a structure in which metal contact is made between the water surface and the T-rail F to 1 via a bearing or the like.

As a result, noise, friction, JI noise, etc. are generated, which may be undesirable depending on the application. In addition, although air and oil guides do not have metal contact, they require a lubricating medium, require maintenance of compressors and hydraulic equipment, and are impossible or limited to use in a vacuum or in an atmosphere that requires a high degree of cleanliness. may be done.

As a solution to this problem, magnetic levitation guidance, shown in a perspective view in FIG. 1, has been proposed. That is, in the figure, 1 is a movable body and 2 is a guide.

The movable body 1 has, for example, four electromagnets 3 to 6, whose magnetic pole faces are indicated by diagonal lines, on its upper and lower surfaces, and two electromagnets 7 and 8, whose magnetic pole faces are indicated by diagonal lines, on both sides. This arrangement provides a total of 12 electromagnets. In this case, the electromagnets on the upper and lower surfaces, the left side and the right side are arranged in symmetrical positions, and each electromagnet 3, 4, 5, etc. is connected to a detector 9 ( However, in the figure, only the electromagnet 3 is shown). The coil current of each electromagnet 3, 4, 5, etc. is controlled by the signal from the accompanying detector 9, and the magnetic attraction force at this time supports the movable body 1 with respect to the guide 2 in a non-contact state. However, the gap with the guide 2 is kept constant.

The movable body 1 is configured to be moved in the direction of the movement axis 10 by the driving force of a linear motor (not shown).

According to such a magnetic levitation guide mechanism, the movable body 1 is guided by the
The movable body 1 can be supported in a non-contact manner, thereby eliminating the drawbacks of the guide mechanism using a lubricating body as described above. The symmetrical arrangement increases bearing rigidity, so
Even if a disturbance acts in a direction that is restrained in a non-contact manner by the attractive force of the electromagnet, it is possible to suppress fluctuations in the gap with the guide 2 to a small value.

However, in such magnetic levitation guidance, there are a large number of electromagnets 3, 4, 5, etc., and in order to support the load of the movable body 1, it is necessary to constantly supply current to the electromagnets 3, etc. This method has disadvantages and is inferior in terms of power consumption due to increased power consumption.

[Object and structure of the invention]

Therefore, in order to solve these drawbacks, the present invention supports the weight of the movable body by the attractive force of the permanent magnet, and modulates the magnetic flux of the permanent magnet with the magnetic flux of the electromagnet to maintain a constant gap in order to obtain a stable floating state. The object of the present invention is to provide a magnetic levitation guide using a composite magnet part that can maintain a high temperature.

Embodiments of the present invention will be described in detail below with reference to the drawings.

[Embodiments of the invention]

FIG. 2 is a configuration diagram showing an embodiment of the magnetic levitation guide according to the present invention. In the figure, 11 is a movable body, 12a, 1
2b is a permanent magnet circuit, 13a, 13b, 13c.

13d is a composite magnet part, 14a, 14b, 14e,
14d is a guide rail. Note that the coordinates are y in the vertical direction.
, the horizontal direction is X, and the moving direction of the movable body 11 is 2. θ
.

φ and F are the coordinates of rotation of these axes.

FIG. 3 is a detailed diagram of the above-mentioned permanent magnet circuit 12b.

be. In the same figure, 15 is a gap, 16 is a permanent magnet,
17a and trb are yokes, and 18 is a support portion.

The permanent magnet circuit 12b is attached to the movable body 11 via the support portion 1B, faces the guide rail 14c with a constant gap t15, and is attached to the movable body 110 by magnetic attraction.
It supports the amount of M.

FIG. 4 is a detailed view of the aforementioned composite magnet section.

In the same figure, Ma, 14b are guide rails, 19 is a displacement sensor, 20 is a permanent magnet, 21&, 21b is a yoke,
22a, 22b are coils, 23a, 23b, 23c
, 23d is a gap, 24a and 24b are permanent magnets 20
25 is the magnetic flux generated when current is passed through the coils 22a and 22b. Here, for convenience of explanation, the magnetic poles N and S of the permanent magnet 20 are as shown in the figure, and the magnetic fluxes 24a, 24b, and 25 are in the direction of the arrows.

In such a configuration, the magnetic flux 2 emitted by the permanent magnet 2o
4a passes through the yoke 21b, passes through the gap 23b, passes through the rail 14a, passes through the gap 23&, passes through the yoke 21a, and returns to the permanent magnet 20. Similarly, the magnetic flux 24b is
1b, clearance 23d, guide rail 24b.

It passes through the gap 23c and the yoke 21a. On the other hand, the magnetic flux of the electromagnet consisting of the coils 22a, 22b and the yoke 21b, when current flows through the yoke 21b, the gap 23b, the guide rail 14a, the gap 23a, the yoke 21a, and the gap 2
3C9 guide rail 14b, plow t 23d and yoke 2
Go around with 1b. Now, assume that the movable body 11 is displaced downward for some reason, the gaps 23a and 23b become narrower, and the gaps t23e and 23d become smaller. Then, the displacement sensor 19 detects this, and in accordance with the signal, K current flows through the coils 22a*22b, generating magnetic flux 25 in the direction of the arrow. Like 123B
.

At 23b, the magnetic flux increases to the sum of the magnetic flux 24a of the permanent magnet and the magnetic flux 25 of the electromagnet, and the attractive force increases.

On the other hand, in the gaps 23c and 23d, there is a difference in magnetic flux, and the attractive force decreases. As a result, from the guide rail to the yoke 21&
.

An upward force acts on 21b, and the increased clearance 2
Return 3a + 23b. On the other hand, gap 23a.

Even when 23b becomes smaller, it can be restored by a similar magnetic flux modulation effect, although the direction is reversed.

In this way, the magnetic flux 241L, 24b of the permanent magnet 20 can be modulated by the magnetic flux 25 of the electromagnet.

FIG. 5 is a block diagram showing an example of a control circuit that controls the current flowing through the coil of the electromagnet based on the detection output of the displacement sensor, where 19 corresponds to the displacement sensor 19 shown in FIG. A differentiation circuit 27 that differentiates the output of the sensor 19 is a signal amplifier and a signal adder ( (hereinafter referred to as signal amplifier/adder), 2
8 is a power amplifier that amplifies the output of this signal amplification/adder 27 and controls the coil 22& by the output, and 29 is a detector inserted between the power amplifier 28 and the coil 22& to detect displacement, its speed, and current. It is a resistor, and its output is configured to be fed back to the signal amplification/adder 27.

In this way, by detecting the displacement, its speed, and the current flowing through the coil 22a and feeding it back to the signal amplification/adder 27, the gaps 23a to 23d can be stably maintained at a constant value.

According to such a configuration, the permanent magnet circuit 12a.

12b supports the load of the movable body 11, ideally there is no need to pass current through the coils of the composite magnet parts 13m, 13b, 13c, and 13d in a balanced state. 11 to guide rail 1
4m.

It can be supported in a non-contact state with respect to 14b, 14c, and 14d.

FIG. 6 is a block diagram showing another embodiment of the magnetic levitation guide according to the present invention, and FIG. 7 is a detailed diagram of the composite magnet portion thereof. In Fig. 7, permanent magnet 20m, 20b is 2
It consists of three parts: yokes 21m, 21b, and 21c. The same parts as the other composite magnet parts in FIG. 4 are given the same numbers. In this embodiment as well, even if the gap 23 & etc. change, the permanent magnet 20a.

The magnetic flux 24m of 20b is the magnetic flux 25 of the electromagnet consisting of the yoke 21b and the coil 22a, and the gap 23b and 2
3c to control the magnetic attraction force, and the gap t2
3a to 23d are held constant. In this case, the control circuit is the same as in FIG. Figure 8 shows the permanent magnet circuit 12.
This permanent magnet circuit 12a is the configuration of movable body 11.
The guide rail 14a is attached to the guide rail 14a and faces the middle part of the guide rail 14a with a gap 15 in between.

FIG. 9 shows an embodiment in which an electromagnet is provided to control movement in the horizontal direction. In the figure, 30a.

30b, 30e, 30d are electromagnets, 31a,
Denoted at 31b are displacement sensors, each of which is arranged to face the guide rail 14 & or the guide rail 14Q so as to generate a magnetic force in the horizontal direction. Here, in the above-mentioned FIG. 4, the yoke 21& and the guide rail 14 are
@.

A magnetic attraction force acts between the yoke 211L and the guide rail 1 in the gaps 23a and 23C between the yoke 211L and the guide rail 1.
4a has a function to restore it even if it shifts in the horizontal direction, but since this force is not a controlled force, there is no damping effect, and the frequency is determined by the mass of the movable body 11 and the rigidity of this horizontal restoring force. When an external force of the same frequency is applied, a phenomenon occurs where the vibration becomes large and the vibration is difficult to damp, but this figure is designed to compensate for this. In other words, in FIG. 9, the electromagnet 30a,
30b, 30c, and 30d can control the current by the control circuit shown in FIG. 5 and provide a damping effect.
The stability of movement in the X and φ directions in FIG. 2 can be improved. In this case, in FIG. 9, two displacement sensors 31&, 31b are sufficient to detect the movement in the two directions of
It is preferable to control using a signal obtained from 31b.

〔Effect of the invention〕

As explained above, the magnetic levitation and vertical straight guide according to the present invention can reduce the number of levitation parts that maintain a constant clearance using control electromagnetic force, and also support the weight of the movable body by the magnetic force of the permanent magnet circuit. , an extremely excellent effect can be obtained by providing an economical device.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional magnetic levitation guide, Fig. 2 is a block diagram showing an embodiment of a magnetic levitation guide according to the present invention, Fig. 3 is a diagram of a permanent magnet circuit, and Fig. 4 is a diagram of a composite magnet section. 5 is a block diagram of the control circuit, FIG. 6 is a diagram of another embodiment of the present invention, FIG. 7 is a diagram of a composite magnet section, FIG. 8 is a diagram of a permanent magnet circuit, and FIG. 9 is a diagram of a permanent magnet circuit. It is a figure of the Example which provided the electromagnet in the horizontal direction. 11--Movable body, 12a, 12b--Permanent magnet circuit, 13a, 13b, 13c, 13d...-Composite magnet section, 14a, 14b, 14c, 14d...Guide rail, 16. 20.20a, 20b @-,, permanent magnet, 17a. 17b, 21a, 21b...Yoke, 22 Iris, 22b
...Coil, 19 +31m+31b * @ @
11 displacement, 26...differential circuit, 27...φ
- Signal amplifier and signal adder, 28...power amplifier. Patent applicant Masa Yamakawa Agent, Nippon Telegraph and Telephone Public Corporation

Claims (1)

[Claims] A movable body is provided with at least four composite magnet parts formed by combining a permanent magnet and an electromagnet and adding a displacement sensor to each combination, and a permanent magnet circuit part that generates a magnetic force that supports the load of the movable body. , the magnetic flux of the permanent magnet can be modulated by the magnetic flux of the electromagnet, and the movable body is supported in a non-contact manner with respect to the guide rail by the magnetic force of the permanent magnet circuit and the control magnetic force of the composite magnet section. Magnetic levitation guidance.