JPH0731126A - Method and apparatus for resetting flat stepping motor from step out - Google Patents

Abstract

PURPOSE:To allow automatic resetting from step-out by providing jet ports opening horizontally in the direction eccentric to the center of a slider oh the side face thereof, and a valve for controlling compressed air supply to the jet ports. CONSTITUTION:A slider 2 is provided with ports 6, 8 for jetting the air horizontally to each side face 21 in predetermined directions at an acute clockwise and counter clockwide inclination angle theta. The jet ports 6, 8 are communicated with an air channel 52 for forming an air bearing 5 between the slider 2 and the stator 1 through control valves 7, 8, respectively. When an abnormal external force acts on the slider 2 to bring about a step-out state, the control valve 7 or 9 is opened to jet compressed air through the jet port 6 or 8. Consequently, rotary force is generated through reaction to rotate the slider 2. When an orthogonal relationship is substantially established with respect to X and Y axes, a self holding state is sustained by the magnetic attraction between the salient pole 13 of the stator 1 and the pole parts of electromagnets of X and Y axes caused by excitation of the electromagnetic drive unit for X axis or Y axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step-out recovery device and method for a mover of a flat step motor.

[0002]

2. Description of the Related Art Conventionally, in equipment for assembling precision machines,
An assembly robot is used that moves accurately between a plurality of working units that perform various assembly operations in a two-dimensional direction. A planar pulse motor that can move in a two-dimensional direction is used to move the assembly robot. (For example, Japanese Utility Model Laid-Open No. 56-120789). This planar pulse motor is, for example, as shown in FIG. 5, an X-axis groove 11 and a Y-axis groove 12 which are parallel to the orthogonal X and Y axes and are provided at equal intervals.
The stator 1 is provided with the grid-shaped convex poles 13 surrounded by. The stator 2 is provided with a slider 2 slidably arranged on the surface of the salient pole 13 with a predetermined gap, and the slider 2 is symmetrically arranged on a straight line Y passing through a predetermined point of symmetry. , The X-axis electromagnetic drive unit 3 that drives the slider 2 in the X direction orthogonal to the straight line Y, and the X axis electromagnetic drive unit 3 that is arranged symmetrically on the straight line X that passes through the symmetry point of the slider 2 and that is orthogonal to the straight line Y and that is orthogonal to the straight line X. A Y-axis electromagnetic drive unit 4 that drives the slider 2 in the Y direction is provided. In order to always maintain a constant gap between the slider 2 and the salient pole 13 of the stator 1, the X-axis groove 11 and the Y-axis groove 12 are filled with resin or the like to form the stator 1 in a flat plate shape, and external compressed air is used. Air passage 5 provided in the slider 2 from the source through the supply port 51
2, the compressed air is ejected from the ejection port 53 into the gap, and the slider 2 is supported by the air bearing 5 formed between the stator 1 and the slider 2. The X-axis electromagnetic drive unit 3 includes two X-axis electromagnets 3 as shown in FIG.
1, 32 are provided, a permanent magnet 33 is provided between the X-axis electromagnets 31 and 32, and a magnetic circuit is formed by the stator 1 and the slider 2. On the magnetic pole surface of one X-axis electromagnet 31,
The magnetic pole portion 31 opposed to the salient pole 13 by being displaced from each other in the X-axis direction by 1/2 pitch of the salient pole 13 of the stator 1.
a and 31b are provided, and magnetic pole portions 32a and 32b are provided on the magnetic pole surface of the other X-axis electromagnet 32 by shifting them by 1/4 pitch from the magnetic pole portions 31a and 31b of the one X-axis electromagnet 31. Similarly, the Y-axis electromagnetic drive unit 4 is provided with two Y-axis electromagnets 41 and 42, a permanent magnet 43 is provided between the Y-axis electromagnets 41 and 42, and a magnetic circuit is formed by the stator 1 and the slider 2. ing. The magnetic pole surface of one Y-axis electromagnet 41 is provided with magnetic pole portions 41a and 41b opposed to the convex pole 13 by being shifted in the Y-axis direction by 1/2 pitch of the pitch of the convex pole 13 of the stator 1, and the other Y On the magnetic pole surface of the shaft electromagnet 42, the magnetic pole portions 41a and 41b of one X-axis electromagnet 41 are provided.
Magnetic pole portions 42a and 42b are provided with a 1/4 pitch shift from the magnetic pole portions. When the slider 2 is moved, by exciting the X-axis electromagnets 31, 32 of the X-axis electromagnetic drive unit 3 and the Y-axis electromagnets 41, 42 of the Y-axis electromagnetic drive unit 4,
Although the magnetic pole moves in every 1/4 pitch of the salient pole 13, the magnetic flux of the magnetic pole having a large area facing the salient pole 13 has the largest magnetic flux, and the magnetic flux has the largest magnetic flux. The respective axis electromagnets are controlled so as to be excited so that the magnetic fluxes of the two magnetic poles displaced from each other are substantially equal.

[0003]

However, in the prior art, when the X-axis electromagnetic drive unit or the Y-axis electromagnetic drive unit is applied with an abnormal external force during movement, or when it is started with an abnormally large load applied. For example, the orthogonal relationship between the stator and the slider may deviate, and the relative relationship between the actual convex pole and each magnetic pole may deviate from the controlled positional relationship and cannot be moved, which is a so-called step-out state. In this step-out state, there is a problem that it is necessary to manually adjust the position of the slider because the normal state cannot be restored even if the excitation of the electromagnet is adjusted. An object of the present invention is to enable a flat step motor to automatically return from a step-out state.

[0004]

In order to solve the above problems, the present invention provides a stator having convex poles provided in a grid pattern at equal pitches along two orthogonal axes, and an air on the surface of the convex poles. X which drives the slider in the directions of the two axes orthogonal to each other by a change in the magnetic attraction force between the slider, which is slidably arranged with a bearing so as to maintain a predetermined gap, and the salient pole.
In a step-out recovery device for a planar step motor including an axial electromagnetic drive unit and a Y-axis electromagnetic drive unit, an injection port opened on a side surface of the slider in a direction eccentric to the center of the slider and in a substantially horizontal direction. And a control valve for supplying / stopping compressed air to the injection port. In the step-out recovery method for the planar step motor, when the slider is out of step, compressed air is jetted from the injection port through the control valve to rotate the slider, the salient pole and the X-axis electromagnetic drive unit, It is a method of maintaining an orthogonal relationship between the convex pole and the X-axis electromagnetic drive unit and the Y-axis electromagnetic drive unit by a magnetic attraction force between the convex pole and the Y-axis electromagnetic drive unit.

[0005]

With the above means, when the slider is out of step, the control valve is opened to inject compressed air from the jet port, and the reaction force produces a rotational force that rotates the slider clockwise or counterclockwise. . When the slider rotates due to the rotational force and approaches an orthogonal relationship with respect to the X and Y axes, the salient poles of the stator and the respective X axis electromagnets and the Y axis generated by the excitation of the X axis electromagnetic drive unit or the Y axis electromagnetic drive unit. Due to the magnetic attraction between the magnetic poles of the electromagnets, the convex poles are automatically aligned with the magnetic poles of the X-axis electromagnets and the Y-axis electromagnets to maintain the self-holding state. Once the self-holding state is maintained, the magnetic attraction force between the convex pole and the magnetic poles of the X-axis electromagnet and the Y-axis electromagnet is larger than the rotational force generated by the injection of compressed air from each injection port, so that the slider is rotated. Stops and the step out condition of the slider is eliminated.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a side sectional view showing an embodiment of the present invention, and FIG. 2 is a bottom view of a slider. In the figure, the slider 2 is provided with two X-axis electromagnetic drive units 3a and 3b and two Y-axis electromagnetic drive units 4a and 4b on the lower surface, and an air passage 52 is provided from an external compressed air source via a supply port 51. The supplied compressed air is ejected from the ejection port 53 provided on the lower surface of the slider 2 facing the stator 1 to eject the stator 1 and the slider 2.
Although the air bearing 5 is formed in the space between and, the basic structure and the moving operation are almost the same as those of the conventional example shown in FIGS. 1 and 2. The points different from the conventional ones are as follows. That is, each side surface 21 (21a, 21b, 21 of the slider 2
c, 21d) in a certain direction, for example, at a certain inclination angle θ that is an acute angle in the counterclockwise direction as shown in FIG. 3,
And an injection port 6 (6a, 6) for injecting air in a substantially horizontal direction
b, 6c, 6d), and each injection port 6 is connected via a control valve 7 to an air passage 52 for forming an air bearing 5 between the slider 2 and the stator 1. Also, each side 2
1, an injection port 8 (8a, 8b, 8c, 8d) for injecting air in a horizontal direction is provided in a direction opposite to the injection port 6, for example, as shown in FIG. Each injection port 6 communicates with the air passage 52 via a control valve 9. Now, for example, an abnormal external force acts on the slider 2 to cause the slider 2 to move to the stator 1 as shown in FIG. 3 or 4.
When it is displaced to a position inclined with respect to the X and Y axes, that is, when the so-called orthogonal relationship is deviated, the control valve 7 or 9 is opened to inject the compressed air from the ejection port 6 or 8.
The reaction force causes a clockwise or counterclockwise rotation force to rotate the slider 2. When the slider 2 approaches an orthogonal relationship with respect to the X and Y axes, the X axis electromagnetic drive unit 3a,
3b or the Y-axis electromagnetic drive units 4a, 4b and the salient poles 13 of the stator 1 and the respective X-axis electromagnets, Y generated by the excitation.
Due to the magnetic attraction between the magnetic poles of the axial electromagnets, the convex poles 13 and the magnetic poles of the X-axis electromagnets and the Y-axis electromagnets are automatically aligned to maintain the self-holding state. Once the self-holding state is maintained, the magnetic attraction force between the salient pole 13 and the magnetic poles of the X-axis electromagnet and the Y-axis electromagnet is larger than the rotational force due to the jet of compressed air from each jet port. Is stopped, and the step-out state of the slider 2 is eliminated. In the above embodiment, an example was described in which the injection port was inclined at an acute angle with respect to the side surface of the slider, but the direction of the injection port was a direction eccentric to the center of the slider, and a rotation moment was applied to the slider. Anything can be used as long as it is generated. Further, the compressed air source supplied to the injection port is not limited to the common one with the compressed air source of the air bearing, and may be independent from each other.

[0007]

As described above, according to the present invention, the step-out condition is automatically canceled by rotating the slider by the injection of compressed air, so that the step-out recovery work does not require any manpower and the plane This has the effect of enabling unmanned operation of the step motor.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing a surface of a slider according to an embodiment of the present invention that faces a stator.

FIG. 3 is a plan sectional view taken along the line AA in FIG. 1 of the embodiment of the present invention.

4 is a plan sectional view taken along the line BB in FIG. 1 of the embodiment of the present invention. FIG.

FIG. 5 is a perspective view showing a conventional example.

FIG. 6 is a side sectional view showing a conventional example.

[Explanation of symbols]

1 stator, 13 convex pole, 2 slider, 21 (21
a, 21b, 21c, 21d) side face, 3 (3a, 3
B) X-axis electromagnetic drive unit, 4 (4a, 4b) Y-axis electromagnetic drive unit, 5 air bearings, 51 supply port, 52
Air passage, 53 jets, 6 (6a, 6b, 6c, 6d)
Injection port, 7 control valve, 8 (8a, 8b, 8c, 8d)
Injection port, 9 control valve

Claims (2)

[Claims] 1. A stator having convex poles provided in a grid pattern at equal pitches along two orthogonal axes, and an air bearing is slidably arranged on the surface of the convex poles by an air bearing. X for driving the slider in the directions of the two orthogonal axes by the change of the magnetic attraction force between the slider and the convex pole.
In a step-out recovery device for a planar step motor including an axial electromagnetic drive unit and a Y-axis electromagnetic drive unit, an injection port opened on a side surface of the slider in a direction eccentric to the center of the slider and in a substantially horizontal direction. And a step-out recovery device for a planar step motor, which is provided with a control valve for supplying / stopping compressed air to the injection port. 2. The method of using the device according to claim 1, wherein the side surface of the slider is an eccentric opening with respect to the center of the slider, and the opening is substantially horizontal. A control valve for supplying and stopping compressed air is provided, and when the slider is out of step, compressed air is ejected from the ejection port via the control valve to rotate the slider, the salient pole and the X-axis electromagnetic drive unit. And the magnetic attraction between the Y-axis electromagnetic drive unit and the Y-axis electromagnetic drive unit
A step-out recovery method for a planar stepping motor, which maintains an orthogonal relationship between an axial electromagnetic drive unit and a Y-axis electromagnetic drive unit.