JPS58133185A - Magnetic floating guidance device - Google Patents

Abstract

PURPOSE:To simplify the constitution and to perform highly accurate positioning at a high speed, by constituting the guidance device, which supports a movable body in a completely frictionless state, by combining a plurality of electromagnets and displacement sensors. CONSTITUTION:A tubular space 25 is formed by a reference surface 22 of a member 21 comrising a magnetic body and second and third reference surfaces 24a and 24b of members 23a and 23b. The movable body 20 is housed in said space 25 so that the body 20 can be freely moved. The minimum of six electromagnets 31-36 and the minimum of five displacement sensors are provided in the movable body 20. The electromagnets 31-36 are excited in response to the outputs of the displacement sensors, and the amounts of the gaps between the reference surfaces 22, 24a, and 24b and the movable body 20 are kept constant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a guide for use in accurately positioning a recording head, etc. with respect to a recording medium in a magnetic disk, etc., and for accurately positioning and moving a workpiece or processing tool. This is a modification of the device.

In such conventional guide devices, in order to make the movement of the moving object smooth, it is necessary to reduce the frictional force between the moving object and the support mechanism as much as possible. mechanisms are commonly used.

However, when using hydraulic or pneumatic pressure, a pump or compressor is required, as well as piping, making maintenance and inspection of these difficult. While the use of hydraulic pressure requires extreme caution, the work is carried out in a vacuum, which poses problems such as the inability to use pneumatic pressure.
There is a growing demand for guidance devices that do not rely on hydraulic or pneumatic pressure.

As a countermeasure to this problem, a hunting bearing guide device as shown in FIG. 1 is first considered.

That is, a cubic movable body 3 is housed as a moving body in a space 1 of a support body 2 made of a magnetic material having a cylindrical space 1 having a square cross section, and four electromagnets are placed on each of the upper and lower surfaces of the cube-shaped movable body 3. 4 to 1, etc., and two electromagnets 8 and 114 are provided on each side of the movable body 3, and these act on the inner surface of the space 1 and the suction force to keep the movable body 3 in a floating state, while at the same time providing magnets to various places. A displacement sensor 10 etc. is provided, which detects the amount of gap between the movable body 3 and the inner surface of the space 1, and controls the attraction force of each electromagnet 4 to S etc. according to the detected force of the displacement sensor K, and 1 and the movable body 3 is always kept constant, the movable body 3 may be driven in the direction of the axis 11 by a linear motor or the like not shown in the figure.

However, in the case of the configuration shown in Fig. 1, a total of 12 electromagnets 4 to 9, etc. are required, and there are four inner surfaces forming space 1, making it difficult to manufacture them accurately. will occur.

The present invention completely satisfies the conventional demands and also provides:
The present invention aims to fundamentally eliminate the drawbacks in FIG. 1, and provides an extremely effective magnetic levitation guide device that uses at least six electromagnets to achieve the same functionality as in FIG.

Hereinafter, the present invention will be explained in detail with reference to FIG. 2 showing an embodiment.

FIG. 2 is a perspective view, FIG. 3 is a plan view of the movable body 20 in FIG. 2, FIG. 4 is a sectional view taken along A-B or CD in FIG. 3, and FIG. This is a sectional view taken along the line E-F, showing the inner first reference surface 22 of the member 21 made of a magnetic material such as a soft magnetic material, and members 23m and 21 that intersect with this at equal angles.
The second reference surface 24m and the third reference surface 24b on the inner surface side of b form a cylindrical space 25 with one side open on the upper surface side and linearly extended.
．． 23m and 23bK form a reference body 26.

On the other hand, the movable body 20, which is movably accommodated in the space 25 and has opposing surfaces 21 and 281 to 211 (l) facing each of the reference surfaces 22.24m and 24b, has a movable body 20 that is movable on both sides of the central part of the beam. Electromagnet 31 facing the first reference plane 22
．． 32'' is provided for each one, and a second reference plane 24m and a third reference plane 24 are provided at each symmetrical part on both sides of one movable body 20.
Electromagnets 33 to 36 facing b are provided in K pieces each and in the same number on both sides.

In addition, a displacement sensor 31 facing the first reference plane 22 is provided at a part of the movable body 20 that is deviated from the central part of the lower surface of the movable body 20. The surfaces 288-28dK are provided with displacement sensors 38-41 facing the first, second and third reference surfaces 24M, 24b in the vicinity of the electromagnets 33-3B. 24b is detected.

Therefore, each electromagnet 31 to 36 is excited according to the detected force of the displacement sensors 37 to 41, and each reference plane 22.24a, 2
4b and the movable body 20 is kept constant, the movable body 20 floats into the space 25 due to the suction force, and the movable body 20 is driven by a near motor or the like (not shown in the figure). From what I do, I stay on the axis 51 in Figure 2,
The movable body 20 can freely move under a frictionless condition.

Originally, due to the balance with the weight of the movable body 20, the movable body 20 would levitate with just the electromagnet ss~3@, but
As shown in FIGS. 4 and 5, when the movable body 20 oscillates about the intersection 54 that is an extension of the center lines 52 and 53 of the electromagnets s3 to s36, the electromagnets 33 to 36 alone cannot prevent the oscillation. In order to prevent this, the attractive force of the electromagnets 311 and 32 corresponding to the detection force of the displacement sensor 37 is met, and the movable body 20 floats in an idle state.
A considerable amount of acceleration is applied by driving a near motor, etc.
If an acceleration greater than gravitational acceleration is applied from below,
Although there is a possibility that the movable body 20 may shift upward from the specified position, it is possible to control the attractive force of the electromagnets 31 to 36 according to the detected force of the displacement sensors 37 to 41. .24m, the amount of clearance in each direction between 24b and the movable body 20 can be kept constant, and the movable body 20 can be maintained at a specified position.

6 and 7 are sectional views corresponding to FIGS. 4 and 5 when the vertical relationship is reversed, the cross-sectional shape of the space 25 is changed, and side surfaces 61a and 61b are provided. , it is possible to obtain results exactly similar to those shown in FIGS.

In other words, the object to be supported by the movable body 20 can be installed in any direction depending on the direction in which it is engaged with the movable body 20! can be determined.

Figure 8 is a block diagram of an electric circuit that excites the coils 311 to asa of the electromagnets 31 to 311 according to the detected force of the displacement sensors 31 to 41, and keeps each gap constant. The circuit between the electromagnet 33 and the coil 331 is illustrated.

That is, the detection force of the displacement sensor 38 is
According to 1, the outputs of the differentiating circuit 62 and the level discrimination circuit 63 are added together, amplified, and then sent to the power amplifier 6.
4), its DC output causes the coil 3 to
3M is excited.

Further, the detected force of the displacement sensor 38 is also applied to a differential circuit 82, and the excitation state is controlled in response to sudden changes in the detected force.

In addition to the current, the current flowing to the coil 1 changes depending on the temperature rise* of the coil 83, so it is connected to the series resistor 8.
5, the p DC component is removed by the level discrimination circuit 68, and only the change is applied to the summing amplifier 61.

However, the configuration shown in FIG. 8 can be freely selected in various ways based on known techniques depending on the conditions.

Therefore, according to the configurations shown in FIGS. 2 to 7, at least 6
31 to 36 electromagnets, the lowest! 54js displacement sensors s7 to 41, the movable body 2 is in a completely frictionless state.
0 is obtained, no hydraulic pressure, pneumatic pressure, etc. are required, and three reference planes 22, 24m, 2 are provided.
Since the purpose can be achieved only with reference body 2
6 is extremely easy to manufacture, the whole can be manufactured at low cost, the driving energy of the movable body 20 is small), and the time required for moving the movable body 20 is reduced, resulting in high speed and Highly accurate positioning control is achieved.

In addition, the displacement sensors 31 to 41 may be of any type as long as they detect the gap amount based on eddy currents, changes in capacitance, etc., and may be commercially available as gap sensors, micro-kyss, non-contact displacement detectors, etc. Just use what you have.

However, the number of electromagnets 31 to 3 may be increased depending on the conditions, but in this case, there is no need to increase the number of displacement sensors 37 to 41. Alternatively, the detection power from a plurality of things may be used after being processed by calculation.

Further, the shape of the movable body 20 and the cross-sectional shape of the space 25 are as follows.
The present invention can be modified in various ways as long as it satisfies the above-mentioned conditions.

According to the above explanation, it is clear that according to the present invention, a floating guide device that does not use hydraulic pressure or pneumatic pressure can be obtained with a simple and inexpensive structure, and high-speed and high-precision positioning control can be achieved. Therefore, remarkable effects can be obtained as a guide device for various food applications.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a conventional example, Fig. 2 and subsequent figures show embodiments of the present invention, Fig. 2 is a perspective view of the entire configuration, Fig. 3 is a plan view of the movable body, and Fig. 4 is a A-B or C-D that can be spelled out in a diagram
5 is a sectional view taken along line E-F in FIG. 3, FIGS. 6 and 7 are sectional views corresponding to FIGS. 4 and 5 showing other embodiments, and FIG. 8 is a sectional view corresponding to FIGS. FIG. 2 is a block diagram of an electric circuit. 20... Movable body, 22e... First reference plane, 24a
... i12 reference surface, 24b ... third reference surface, 2
5...Space, 26...Reference body, 271281~
28d @ @ @ Opposing surface, 31 to 316-... Electromagnet, 31 to 41-... Displacement sensor. Patent Applicant Nippon Telegraph and Telephone Public Corporation Agent Masaki Yamakawa Figure 3 Figure 4 28b, 28d Figure 5 Figure 7 @

Claims (1)

[Claims] a reference body made of a magnetic material forming a linear cylindrical space with one side open and having a length of Kg by a first reference plane and second and third reference planes that intersect at equal angles with the wrinkled first reference plane; A movable body housed in a movable manner in a space, an electromagnet facing the first reference plane provided on both sides of the cough movable body, and facing the first reference plane provided on the movable body. a displacement sensor, an equal number of electromagnets each facing the second and third reference planes provided at symmetrical parts on both sides of the movable body, and electromagnets each provided in the vicinity of the electromagnets, respectively. A magnetic levitation guide device patented as comprising second and third reference planes and an equal number of opposing displacement sensors.