JPH0628504B2 - Non-contact type actuator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a non-contact type actuator suitable for use in semiconductors that are resistant to dust, biotechnology-related factories, and the like.

(Prior Art) Conventionally, a direct drive type transport device using a linear pulse motor (hereinafter, referred to as LPM) has been developed.
This type of prior art is described, for example, in Editors and Publishers "The Institute of Electrical Engineers", "Linear Motors and Their Applications," pages 124-127.

However, in this transfer device, the transfer part including the work is LPM
It is designed to be supported by mechanical linear bearings separately from. That is, the LPM employs a mechanical structure that gives only the thrust required to move the transport unit.

(Problems to be Solved by the Invention) As described above, the transport apparatus using the LPM has the following problems because it has a mechanical bearing.

(1) Mechanical frictional contact cannot be avoided, and dust is generated from this frictional contact part.

(2) In a vacuum, it evaporates to lubricating oil, polluting the atmosphere and causing bearing burnout.

(3) Noise and vibration are generated from the friction contact part.

(4) High precision positioning is difficult because it has mechanical contact parts.

The present invention eliminates the above-mentioned problems, and magnetically levitates and propels a mover by a magnetic force between a compactly constructed stator and mover, and moreover, a mover having an actuating portion can smoothly move back and forth directly. An object is to provide a driven non-contact actuator.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a non-contact actuator, comprising: (a) a plurality of teeth aligned in one direction at each tip and having a predetermined spacing. Which has a core member provided with at least four pole pieces, the propulsion guide magnetic poles being excited by the propulsion guide coils respectively wound on the pole pieces, and adjacent to the propulsion guide magnetic poles. A linear motor magnetic pole in which a suction magnetic pole excited by a suction coil wound on a core member so as to excite two of the pole pieces to the same pole is integrated; and (b) the linear motor magnetic pole. A stator having an auxiliary electromagnet having magnetic poles that act to generate a magnetic field;
(c) A tooth row aligned with a constant pitch is formed on the surface of the stator facing the tooth surface of the linear motor magnetic pole, and has a surface facing the magnetic pole of the auxiliary electromagnet and one end A mover having an actuating portion extending axially from
(d) a plurality of displacement detection means for detecting relative displacement between the stator and the mover, and (e) adjusting a gap between the stator and the mover based on a detection value from the displacement detection means. Then
In addition, a control means for propelling the mover in a magnetically levitated state is provided.

(Operation) According to the present invention, the mover having the operating portion is held in a non-contact state by the magnetic force of the attraction magnetic pole in the linear motor magnetic pole, and is moved by the magnetic force of the propulsion guide magnetic pole in the linear motor magnetic pole. The child propels, and the actuating part moves forward and backward. Also,
The magnetic force of the auxiliary electromagnet cooperates with the magnetic pole of the linear motor to control the attitude and propulsion of the mover.

Further, in the attitude control of the mover, the displacement state of the mover is monitored by the electronic control unit via the displacement detection means, and the attraction pole in the linear motor magnetic pole and the auxiliary electromagnet are respectively monitored according to the displacement state. The excitation current is adjusted so that it can be smoothly performed.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 to 3.

In the figure, 1 is a fixed frame, 2, 2a to 2d, 2a 'to 2d' are linear motor magnetic poles fixed to this fixed frame, 3, 3a to
Reference numeral 3c is an auxiliary electromagnet. The magnetic poles of the linear motor and the auxiliary electromagnet are attached to the fixed frame 1 to form a stator. Reference numeral 4 is a mover, 5 is a rod which is an operation portion integrally formed with the mover 4, 6, 6a to 6c, 7, 7a
7c is a displacement detector, and A is a control means. Further, 8 is an electronic control device, 8-1 is a CPU (central processing unit), 8-
2 is a memory, 8-3 is an input interface, 8-4 is an I / O interface, 8-5 is an MDI (manual data input) device, 9 is a drive circuit, 10 is a power supply, 11 is a reference plane for displacement detection (target). ).

Next, the outline of the structure and operation of this actuator will be described.

(1) Movable element 4 with non-contact state of movable element having rod
Will be supported in a non-contact state. That is, as shown in the drawing, the mover 4 has linear motor magnetic poles 2a to 2d and 2a 'to 2 arranged to face the upper and lower surfaces of the mover 4, respectively.
It is attracted by the magnetic force of the attraction magnetic pole d'and is held in a non-contact state. Further, auxiliary electromagnets 3a to 3c are arranged to control the attitude of the mover 4 in the horizontal plane.

(2) Propulsion of mover having rod The linear motor magnetic poles 2a to 2d and 2a 'to 2d' have propulsion guide magnetic poles for propelling the mover 4, and the magnetic poles are excited to move the mover. 4 steps up.

(3) Attitude Control of Movable Element Having Rod The attitude of the movable element 4 is controlled by adjusting the exciting currents of the attraction magnetic pole and the auxiliary electromagnet in the magnetic pole of the linear motor on which the magnetic force acts on the movable element 4. That is, positioning is performed by adjusting the exciting current of the attraction magnetic pole in the linear motor magnetic pole so that the flat plate-shaped mover 4 becomes horizontal. After that, the exciting current of the auxiliary electromagnets arranged on both side surfaces of the mover 4 is adjusted to adjust the lateral direction to a predetermined position. The distance between the mover 4, the magnetic pole for attraction, and the auxiliary electromagnet is detected by the displacement detector, and an appropriate attitude control is performed by the electronic control unit.

Hereinafter, one embodiment of the present invention will be sequentially described.

As shown in FIG. 1 and FIG. 2, a plurality of tooth rows aligned with a certain pitch are formed on a mover 4 having a rod (hereinafter referred to as a mover). In order to magnetically attract the movable element 4 to bring it into a non-contact state and to propel it, the linear motor magnetic pole 2 is provided at a position with a certain distance from the movable element 4. In this linear motor magnetic pole 2, a suction coil of the mover 4 is wound around the base of the core member 21, and a propulsion guide coil is wound around the tip thereof. That is, the attraction magnetic pole for magnetically attracting the mover 4 for non-contact support and the magnetic pole for propulsion guidance for magnetically propelling the mover 4 are integrated. That is, it is constructed by stacking ferromagnetic materials such as electromagnetic steel plates punched in a concatenated shape having a concave shape, and suction coils 26 and 27 (see FIG. 2) on the outer periphery of each concave portion of the core member 21.
Are wound so that the polarities are opposite to each other. This core member
Each tip of 21 comprises a first pole piece, a second pole piece, a third pole piece and a fourth pole piece, and each pole piece has a propulsion guide coil 28,
29, 30, 31 are wound, the first magnetic pole 22, the second magnetic pole 23, the third
A magnetic pole 24 and a fourth magnetic pole 25 (see FIG. 4 (a)) are formed. The pitch of the teeth provided on these magnetic poles 22, 23, 24, 25 is the same as the pitch of the teeth of the mover 4, but the pitch of the magnetic pole teeth is deviated. On the other hand, the second magnetic pole 23 has a 1/2 pitch, and the third magnetic pole 24 has a 1/4 pitch.
The pitch and the fourth magnetic pole 25 are arranged so as to be displaced by 3/4 pitch relative to the pitch of the teeth of the mover 4.

Next, the operation of this magnetic pole of the linear motor will be described with reference to FIG.

(1) When an electric current in the direction of the arrow shown in the drawing (to be the positive direction) is passed only through the suction coils 26, 27, a magnetomotive force is generated, and a magnetic flux flows as shown in FIG. 4 (a).

(2) When a current is applied only to the propulsion guide coils 28 and 29 that excite the first magnetic pole 22 and the second magnetic pole 23, a magnetomotive force is generated, and FIG.
Magnetic flux flows as shown in (b). When a current is passed in the negative direction, the direction of magnetomotive force is reversed, and the magnetic flux also flows in the opposite direction. The same applies to the propulsion guide coils 30 and 31 that excite the third magnetic pole 24 and the fourth magnetic pole 25.

Here, a certain constant current Ic is passed through the suction coils 26 and 27. That is, the magnetomotive force shown in FIG. 4 (a) is generated to flow the magnetic flux, and at the same time, the propulsion guide coil 28,
When a positive current Ia is applied to 29, the magnetomotive forces of the current Ic and the current Ia are strengthened in the first magnetic pole 22, while the magnetomotive forces of the current Ic and the current Ia are canceled in the second magnetic pole 23, so that the mover 4 moves. A stable restoring force is generated at the position shown in Fig. 4 (b).
That is, an attempt is made to stabilize the position such that the convex portions of the teeth of the first magnetic pole 22 and the convex portions of the teeth of the mover 4 coincide with each other.

Next, when the current Ia is set to zero and the current Ib is set to positive, magnetic flux tends to flow through the third magnetic pole 24, and thrust is generated in the mover 4 so that the mover 4 stabilizes at the position shown in FIG. The child 4 steps by 1/4 pitch.

Next, if the current Ib is made zero and the current Ia is made negative, the second
Since the magnetomotive force with respect to the magnetic pole 23 is strengthened and the magnetic flux flows, the step advances by 1/4 pitch.

In this way, Ia (positive) → Ib (positive) → Ia (negative)
→ By switching the currents of the propulsion guide coils 28, 29 and 30, 31 such as Ib (negative), the mover 4 steps in steps of ¼ pitch.

As described above, the linear motor magnetic poles 2 are arranged on both sides of the mover 4, and the linear motor magnetic poles 2 arranged on both sides of the mover 4 with respect to the moving direction of the mover 4. If they are excited in line symmetry evenly, even if an imbalance of the magnetic forces of the first magnetic pole 22 to the fourth magnetic pole 25 of the linear motor magnetic pole 2 occurs, this is canceled out and the characteristics are symmetrical around the reference point. As a result, the mover 4 is smoothly moved.

With such a configuration, non-contact support of the mover and propulsion of the mover can be achieved by a compact linear motor magnetic pole, and a conventional mechanical bearing mechanism such as a rolling bearing can be completely abolished.

Next, the attitude control of the mover will be described.

As shown in FIGS. 1 and 3, the plate-shaped mover 4 is provided.
Four linear motor magnetic poles 2a-2
d, similarly, four linear motor magnetic poles 2a 'to 2d' are fixed below the mover 4 so as to face each other with a predetermined gap. Auxiliary electromagnets 3a, 3b and 3c are arranged on the sides of the mover 4, respectively. This auxiliary electromagnet regulates the lateral position of the mover 4.

The following definitions are made here. As shown in FIG. 5, the rod direction of the mover 4 is the Z direction, the transverse direction of the mover 4 orthogonal to this is the Y direction, and the directions orthogonal to these Z and Y directions are the X directions. . Therefore, the rotation about the Z-axis is the roll Φ, the rotation about the Y-axis is the pitch θ, and the rotation about the X-axis is yaw ψ.

Here, the control of the roll Φ of the mover 4 can be performed by adjusting the exciting current between the linear motor magnetic poles 2a and 2b, 2c and 2d about the Z axis. That is, this adjustment state is based on the displacement detectors 6a, 6b and 6a, 6c.
The electronic control unit 8 adjusts the exciting current of each magnetic pole of the linear motor based on the detected value. Also,
Similarly, the pitch θ of the mover 4 can be controlled by adjusting the exciting currents between the linear motor magnetic poles 2a and 2c and the linear motor magnetic poles 2b and 2d centering on the Y axis. Further, the yaw ψ control of the mover 4 is performed by the auxiliary electromagnet 3 centered on the X axis.
This can be done by adjusting the exciting current between a, 3b and 3c.

Next, as described above, the control of the propulsion in the Z direction is performed by the generation of the magnetomotive force in the propulsion guide coil of the linear motor magnetic pole.

Next, attitude control during propulsion of the non-contact actuator will be described.

In general, the attractive force F of the electromagnet when magnetically levitating the mover is F (I, D) = K (I ² / D ² ) ... (1) F: magnetic attractive force, I: electromagnet exciting current, It is expressed as D: magnetic pole gap, K: proportional constant.

Therefore, in the control using the magnetic attraction force, since the above equation (1) is generally nonlinear, each constant is linearized around the reference value to perform the first-order approximation for control. That is,
The steady attractive force F ₀ is determined, the gap setting value D ₀ is determined, the exciting current I _{0 of the} electromagnet required at that time is obtained from the above equation (1), and the change from the reference value at this time is F = F ₀ + (ΔF D = D ₀ + ΔD I = I ₀ + ΔI), the above equation (1) is Taylor-expanded and linear approximation is performed. F (I, D) = F (I ₀ + ΔI, D ₀ + ΔD) = F ₀ + (2KI ₀ / D ₀ ² ) ΔI − (2KI ₀ ² / D ₀ ³ ) ΔD, and excluding the stationary component, ΔF = (2KI ₀ / D ₀ ² ) ΔI − (2KI ₀ ² / D ₀ ³ ) ΔD ... (2), and control is performed based on this equation (2). This control is generally a method in which the gap of the magnetic pole is detected by a gap detector, and the difference from the set value is set as ΔD, and this ΔD is fed back to the manipulated variable ΔI through a compensation circuit.

At this time, as a compensation circuit, for example, proportional-derivative (PD)
Circuits and proportional-integral-derivative (PID) circuits are used.

Further, when there are a large number of electromagnets and detectors, respectively, a multi-input multi-output control method is used.

Further, the block diagram of the gap control with the addition of the compensation element using the above equation (2) is as shown in FIG. Here, M is the equivalent mass of the magnetically levitated movable body K _d = 2KI ₀ ² / D ₀ ³ D _i = 2KI ₀ / D ₀ ² , the compensation circuit 92 is composed of PD or PID, and the disturbance a is blocked. When the gap b of the gap detector is changed by being added to 91, this change amount is fed back to the input side of the block 91 via the compensation circuit 92 and the block 93.

With such a control system, one electromagnet with two electromagnets
As shown in FIG. 16, when two electromagnets 122 and gap detectors 101 and 102 are provided on the fixed body 121 and the mover 124 is magnetically levitated, the circuit configuration as shown in FIG. 17 is adopted. Here, 101 and 102 are gap detectors, 103 is a vertical displacement converter, 104 is a rotational displacement converter, 105 and 106 are compensation circuits, and 10
7 and 108 are distributors, 109 and 110 are addition points, 111 and 112 are drive amplifiers, and 113 and 114 are electromagnets.

As an example of a control method for controlling the two degrees of freedom (two degrees of freedom only on the paper surface) based on the detected values of the gaps from the gap detectors 101 and 102, the compensation circuits 105 and 106 shown in FIG. If a PD circuit is used for, as shown in FIG.
Since the position of the center of gravity G of the magnetic levitation mover shifts, the two electromagnets need to generate a large force in order to maintain the set gap between the two electromagnets.

In the case of the PD control shown in FIG. 18, a steady deviation (inclination) occurs in order to generate different forces on the left and right sides. In other words, because of this inclination, it is possible to obtain a current difference that is a gain times the error with respect to the setting gap, that is, a force difference.

Further, in order to eliminate this steady-state deviation (slope), if control is performed using a proportional-differential-integral circuit for the compensation circuits 105 and 106 shown in FIG. 17, the mover 12 as shown in FIG.
No. 4 can control without tilt while keeping the setting gap. That is, when the control system has an integral element,
When the center of gravity approaches the magnetic pole, the load that the magnetic pole should support increases. Therefore, the gap of the electromagnet is widened. Then, the integrating element gradually integrates the error so that the error in the gap becomes zero. The drive amplifier then uses its integral element output to increase the coil current. The coil current continues to increase until the integrated output becomes constant at a certain value, that is, the error becomes zero. In this way, in a control system that includes an integral element, "increase of load → expansion of gap → integration of error → increase of current → restoration of gap"
It is commonly used because it can be controlled.

However, since the integral element is included, there arises a problem that the response to external disturbance force is deteriorated.

Further, in the embodiment of the present invention, the mover does not have an active magnetic pole but has a magnetic pole on the fixed side,
In such a configuration, the load carried by each magnetic pole changes due to the movement of the center of gravity of the mover. When moving at high speed, the frequency at which the load changes increases. Generally, the steady deviation can be eliminated by adding an integral element to the servo system.
Since integration time is required, high frequency characteristics cannot be expected. Furthermore, it tends to be unstable due to signal delay.

When the non-contact type actuator of the present invention is driven, the center of gravity of the mover moves without fail and the supporting load of each magnetic pole changes. Therefore, in the present invention, this load change is preliminarily taken, and the magnetic attraction force change equal to the load change is applied to the linear motor magnetic pole by using the gravity center movement information. This center-of-gravity movement information is stable because there is no delay such as when using an integral element. Further, in this actuator, since the magnetic poles for propulsion and the magnetic poles for attraction are integrated, if the position of the center of gravity of the mover in the initial stage of levitation is known, the subsequent movement is performed by the integrated magnetic pole of the linear motor. Can also be known from the input amount to the magnetic pole of the linear motor without a detector (provided that the load does not change much).

Therefore, in this embodiment, as shown in FIGS. 13 and 14, a position detector for detecting the position of the center of gravity of the mover.
79 is provided, the center-of-gravity position calculator 80 calculates the center-of-gravity position from the position information, and the addition points 82 and 83 are added via the distributor 81.
To the respective electromagnets 86 and 87, smooth and stable levitation control can be performed. In addition,
Here, 71 and 72 are gap detectors, 73 is a levitation displacement converter, 74 is a propulsion displacement converter, 75 and 76 are compensation circuits, 77 and 78 are distributors, and 84 and 85 are drive amplifiers.

In this way, a method for calculating the force to be supported by the electromagnet based on the position of the center of gravity of the mover, calculating the exciting current of each electromagnet, and controlling the exciting current value of the electromagnet in addition to the drive amplifier is adopted.

As the position detector, it is possible to employ various means such as a photoelectric encoder that reads a mark that changes corresponding to the position attached to the mover.

When controlling the rod-type actuator of the above-mentioned embodiment of the present invention by using such a mover attitude control means, four suction devices are used based on the center-of-gravity position information from the center-of-gravity position calculator. Calculate the suction force that the magnetic pole should suck,
By distributing the exciting current to each of the four magnetic poles for attraction,
The attitude of the rod type actuator can be controlled.

Further, the control of the mover will be sequentially described.

First, when the center of gravity G (see FIG. 3) exists at the origin, in this state, the magnetic poles of the linear motor and the auxiliary electromagnet are excited so that the magnetic forces acting on the mover 4 are balanced. Apply current. The state of the exciting current at this origin is stored in the memory 8-2 of the electronic control unit 8.
That is, each of the linear motor magnetic poles 2a to 2d and 2a 'to 2
The attracting magnetic pole d'and the exciting currents of the auxiliary electromagnets 3a to 3c are read from the input interface 8-3 of the electronic control unit 8 and stored in the memory 8-2 to be used as initial values. Therefore, when an exciting current is applied to the propulsion guide coil of the magnetic poles of the linear motor, the mover 4 steps and the rod 5 propels. At this time, a microstep voltage (described in detail later) is applied to the propulsion guide coil.

Here, as shown in FIG. 3, displacement detectors 6a to 6c for detecting displacement in the X direction and displacement detectors 7a to 7c for detecting displacement in the Y direction are arranged. Note that the number of displacement detectors is not limited to this number and can be increased. Also, this arrangement can be changed appropriately.

Then, when the rod 5 propels and the mover 4 moves, the displacement detectors 6a to 6c move the mover 4 in the X direction along with the movement.
The displacement detectors 7a to 7c monitor the gap between the movable element 4 in the Y direction and the gap between the movable element 4 and the detectors. The suction force of the stator is adjusted.

That is, in position control in the X direction, the displacement detectors 6a to 6c fixed above the mover 4 detect the gap in the X direction of the mover 4 and eliminate the deviation from the reference value when the deviation occurs. This is performed by adjusting the exciting current of the suction coil of the linear motor magnetic pole.

Next, the position control in the Y direction is performed by adjusting the exciting currents of the auxiliary electromagnets 3a, 3b, 3c provided on the side surface of the mover 4. That is, when the displacement detectors 7a to 7c detect the gap between the side surface of the mover 4 and the electromagnet, and a deviation from the reference value occurs,
The position control in the Y direction is performed by adjusting the exciting currents of the auxiliary electromagnets 3a to 3c so as to eliminate the deviation.

The position in the Z direction is stored in advance as the origin position, and the amount of displacement can be recognized and the position of the mover 4 can be controlled by the number of pulses applied to the magnetic pole of the linear motor from this position.

Further, the mover can be controlled as follows.

First, the origin position of the mover 4 is determined by a dog switch or the like, and the mover 4 is non-contact supported at this position. That is, the drive circuit 9 is previously attached to the linear motor magnetic pole and the auxiliary electromagnet.
An exciting current is caused to flow through the movable element 4 to bring it into a non-contact state.

Next, in the non-contact state, the detected value from each displacement detector is read into the electronic control unit 8 through the input interface 8-3, and the read value and the reference value of each displacement detector (become a reference. The air gap value) is compared, and the exciting current value of the suction coil in each magnetic pole of the linear motor is adjusted in the drive circuit 9 via the I / O interface 8-4 so that the deviation becomes zero.

By thus performing the feedback control, it is possible to smoothly perform the attitude control of the mover.

Next, the micro step drive of the mover will be described.

Here, the micro-step drive is a method in which two-phase currents having a 90 ° phase shift are applied to two windings of a magnetic pole of a linear motor to drive as a synchronous motor. For example, the propulsion currents Ia and Ib of the mover 4 are used. To supply a waveform as shown in FIG. FIG. 7 is a block diagram of a microstep drive system, in which 41 is a ring counter and 42 and 43 are ROs.
M, 44 and 45 are D / A converters, 46 and 47 are drive amplifiers, and the linear motor magnetic pole 2 is provided after the drive amplifiers 46 and 47.
Are connected.

The drive circuit for the suction coils 26 and 27 is omitted here.

As shown in this figure, when the movement command value is input to the ring counter 41, the waveform data stored in the ROMs 42 and 43, that is, the sine and cosine values are read out, and the D / A converters 44 and 45 are read. The analog amount is driven via the drive amplifier 46, 47
Is input to and amplified by the propulsion guidance coils 28, 29, 30,
Added to 31. In the waveform, the ratio between the A phase and the B phase is determined by the electrical angle position (time), which is output according to the electrical angle position to move the mover 4. When a voltage amplifier is used as the drive amplifier, passive diping can be expected. With this configuration, the mover 4 can move smoothly and can be positioned at a minute distance.

By the way, since this actuator drives the mover in a non-contact state, the mechanical diping with respect to the movement of the mover is very small. Therefore, even if the micro step drive is performed, some vibration is accompanied. To suppress this vibration, the following configuration is used.

The phase of the plurality of linear motor magnetic poles arranged in the propulsion direction with respect to the teeth of the mover 4 is shifted from each other by π / 4. That is, at some point, the linear motor magnetic poles 2a, 2
In the propulsion guide coil b, the linear motor magnetic pole 2 is used so as to generate the magnetomotive force shown in FIG. 8 (a).
In the propulsion guide coils c and 2d, the respective linear motor magnetic poles are arranged so as to generate a magnetomotive force as shown in FIG. 8 (b).

Thus, the position of the magnetic pole of the linear motor is π / 4 in electrical angle.
If they are shifted, the thrust and diping characteristics will be uniform,
Compared with the case of the in-phase arrangement, the diping becomes larger and smooth driving becomes possible. That is, it is possible to improve the resolution and reduce the vibration.

In the above, the case of the micro step drive has been described.
The pattern is as shown. That is, when the motor magnetic pole I (linear motor magnetic pole 2a or 2b) is one-phase excited, the motor magnetic pole II (linear motor magnetic pole 2c or 2d) is two-phase excited, and vice versa.

Here, plus and minus in the table are polarities of the coil voltage (or current) at the time of bipolar driving of the step motor.

As described above, damping can be performed by shifting the excitation phase not only in the micro step drive but also in the case of a normal step motor.

According to the above description, the case where the phases of the linear motor magnetic poles 2c and 2d are advanced by π / 4 with respect to the linear motor magnetic poles 2a and 2b has been described.
a / 2b, the linear motor magnetic poles 2c, 2d are π /
It may be delayed by four. In this case, it is the same as the moving direction of the mover is changed. Furthermore, n × π / 4 (n =
1,3,5,7) Even if it is advanced or delayed, the above-described effects can be obtained. That is, one is 2
In the case of phase excitation, it is advisable to make the other one phase excitation.

Next, one embodiment of the position closed loop control of this non-contact rod type actuator will be described with reference to FIG.

Here, a traveling direction position detector is provided. Then, the linear motor magnetic pole and the traveling direction position detector are supported and fixed by the fixed frame. Further, the drive circuit for the suction coils 26, 27, the gap detector, the gap control circuit, etc. are omitted.

In the figure, 51 is a deviation counter for outputting an error between the current position and the movement command value, 52 is a D / A converter, 53 is a controller including a PID controller, 54 is a code discriminator, and the phase is advanced. Delay, that is, output a plus or minus signal. 55 is an absolute value circuit and 56 is a phase output device, which is normally fixed at 90 °. 57 is a phase adder / subtractor, 58 and 59 are ROMs, 60 and 61 are D / A converters, 62 and 63 are multipliers, 64,
Reference numeral 65 is a drive amplifier, and 66 is a traveling direction position detector, which detects the phase of the mover 4 with respect to the teeth. The waveform is output as, for example, a sine wave or a cosine waveform. 67 is a position converter, for example, an R / D (resolver / digital) converter, which outputs the current phase output to the phase adder / subtractor 57 and outputs the speed output to the addition point 68 to form a speed loop. . The position converter 67 also outputs a current position signal to the deviation counter 51 to form a position loop.

With this configuration, in the case of open loop control, it is possible to prevent out-of-step that easily falls.

In the above embodiment, four magnetic poles of the linear motor are arranged on the upper side and four on the lower side with the mover sandwiched therebetween, and tooth rows are formed on the surfaces of the movable pieces facing each other. Although three auxiliary electromagnets are arranged in the
These structures can be variously modified depending on the weight and shape of the mover. For example, (1) As shown in FIG. 11, as the constitution of the stator side, one linear motor magnetic pole 2e is provided on the upper side, and a total of four auxiliary electromagnets 3g to 3j are provided on the lower side. A total of three auxiliary electromagnets 3d to 3f are arranged on one side. A tooth row is formed only on the upper surface of the mover 4. Although not shown, two or three linear motor magnetic poles may be arranged on the upper side. Further, the number and arrangement of the linear motor magnetic poles or auxiliary electromagnets arranged on the lower side can be designed arbitrarily.

(2) As shown in the twelfth example, two linear motor magnetic poles 2f and 2g are provided on the upper side of the mover 4 in the traveling direction, and two linear motor magnetic poles 2h and 2i are laterally provided on the lower side. A total of three auxiliary electromagnets 3d to 3f are arranged laterally, and tooth rows are formed on both upper and lower surfaces of the mover 4. Although not shown, one or three elements are provided above the mover 4.
It is possible to provide individual linear motor magnetic poles,
The number and arrangement of the linear motor magnetic poles or auxiliary electromagnets on the lower side can be appropriately designed.

Further, the operating portion provided on the mover is not limited to the rod, and can be modified into various shapes.

Further, although the example of the digital control means is shown in the above-mentioned embodiment, the conventional PID adjustment can be performed by using an analog circuit.

The present invention is not limited to the above embodiment,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described in detail above, according to the present invention, in the non-contact actuator, at least four teeth each having a plurality of teeth aligned in one direction at each tip are installed at predetermined intervals. A pole member provided with a pole piece, and a propulsion guide magnetic pole excited by a propulsion guide coil wound around the pole piece, and two of the pole pieces adjacent to the propulsion guide magnetic pole. It has a linear motor magnetic pole integrated with a magnetic pole for attraction which is excited by an attraction coil wound around a core member so as to be excited to a pole, and a magnetic pole which cooperates with the linear motor magnetic pole to generate a magnetic field. A stator provided with an auxiliary electromagnet, and a tooth row aligned with a constant pitch is formed on a surface of the stator facing the tooth surface of the linear motor magnetic pole, and a surface facing the magnetic pole of the auxiliary electromagnet. And from one end A mover having an actuating portion extending in the axial direction, a plurality of displacement detecting means for detecting relative displacement between the stator and the mover, and the stator and the movable body based on detection values from the displacement detecting means. Since the gap between the children is adjusted and the control means for propulsing the mover in the magnetically levitated state is provided, (1) the mover having the operating portion can be propelled in a non-contact state, The control is also extremely smooth.

(2) The actuating part is provided on the mover and constitutes a direct drive type actuator, and the structure is simple and compact.

(3) It is not necessary to connect a wire for supplying electricity to the mover, the mover does not pull the wire, and the mover moves smoothly.

(4) To drive, it is only necessary to provide a tooth row on the mover, and the propulsion guide coil and suction coil are provided on the stator side, so the heat generated by the coil is effective due to heat conduction on the stator side. It can be absorbed by and does not cause a temperature rise in the operating part.

(5) No dust is generated because no mechanical bearing is required.

It can also be used in vacuum.

No noise or vibration from the drive source.

Highly accurate positioning is possible.

No maintenance such as refueling is required.

As described above, the present invention has various advantages and is particularly suitable for use in a harsh environment such as a high vacuum atmosphere such as a dust-free semiconductor factory, a biotechnology-related factory, or a space factory. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a non-contact rod type actuator showing an embodiment of the present invention, FIG.
FIG. 4 is an overall configuration diagram thereof, FIG. 4 is an operation explanatory diagram of a linear motor magnetic pole, FIG. 5 is an explanatory diagram of an operation direction of a mover, FIGS. 6 and 8 are microstep drive current waveform diagrams, and FIG. Is a microstep drive system configuration diagram, FIG. 9 is an excitation sequence diagram, FIG. 10 is a closed loop control system configuration diagram,
11 and 12 are layout diagrams of an electromagnetic device showing another embodiment,
FIG. 13 is an explanatory diagram of a mover control having a center of gravity position detecting means, FIG. 14 is a block diagram of the mover control, FIG. 15 is a block diagram of general gap control, and FIGS. 16 and 18 are general. 17 is an explanatory diagram of PD control of the mover, FIG. 17 is a block diagram of general mover control, and FIG. 19 is an explanatory view of PID control of the general mover. 1 ... Fixed frame, 2, 2a-2d, 2a'-2d '... Linear motor magnetic pole, 3, 3a-3c ... Auxiliary electromagnet, 4 ...
... mover, 5 ... rod, 6, 6a to 6c, 7, 7a to
7c ... displacement detector, 8 ... electronic control device, 9 ... driving circuit, 10 ... power supply, 11 ... reference plane, 21 ... core member, 22 ...
… First magnetic pole, 23 …… Second magnetic pole, 24 …… Third magnetic pole, 25 ……
4th magnetic pole, 26, 27 ... Suction coil, 28-31 ... Propulsion guide coil.

Claims (10)

[Claims] 1. A core member having at least four pole pieces, each of which has a plurality of teeth aligned in one direction and is installed at a predetermined interval at each tip, and is wound on each pole piece. A propulsion guiding magnetic pole excited by a rotating propulsion guiding coil and a suction coil wound around a core member so as to excite two of the pole pieces to the same pole adjacent to the propulsion guiding magnetic pole. A linear motor magnetic pole integrated with a suction magnetic pole excited by (b) an auxiliary electromagnet having a magnetic pole that cooperates with the linear motor magnetic pole to generate a magnetic field; A tooth row aligned with a constant pitch is formed on the surface of the stator facing the tooth surface of the linear motor magnetic pole, and has a surface facing the magnetic pole of the auxiliary electromagnet and is axially oriented from one end. A mover having an extending operating part, and (d) a space between the stator and the mover. A plurality of displacement detecting means for detecting relative displacement, (e) adjusting the gap between the stator and the movable element based on the detection value from the displacement detecting means, and in the magnetically levitated state of the movable element. A non-contact type actuator, comprising: a control unit that performs propulsion. 2. The gap control means for adjusting the gap between the stator and the mover by changing the exciting current of the suction coil on the basis of the detection value from the displacement detection means, and the control means. The non-contact actuator according to claim 1, further comprising a propulsion control unit that changes the current to propel the mover in a magnetically levitated state. 3. The non-contact actuator according to claim 1, wherein the magnetic poles of the linear motor are arranged on both sides of the movable element. 4. The linear motor magnetic poles arranged on both sides of the mover are arranged so as to be uniformly excited in line symmetry with respect to the propelling direction of the mover. The non-contact type actuator according to item 3. 5. A means for supplying a sine-wave current and a cosine-wave current to the propulsion guide coil, and performing micro-step drive by the current flowing in each of these phases. The non-contact type actuator according to item 1. 6. A means for detecting the displacement of the mover in the traveling direction by the displacement detecting means during the micro-step driving, and performing a closed loop control based on the detected value so as to obtain a constant excitation advance angle. The non-contact actuator according to claim 5, characterized in that: 7. An arrangement according to claim 1, wherein each of the magnetic poles of the linear motors arranged in the traveling direction of the mover is arranged so as to shift each excitation phase by π / 4. Contact actuator. 8. The displacement detecting means detects states of vertical movement, lateral movement, yawing, pitching and rolling,
The non-contact actuator according to claim 1, further comprising means for controlling the mover to a preset position by the control means based on the detected value. 9. The control means detects a barycentric position of the mover, a means for storing the detected barycentric position, and the barycentric position and displacement of the stator are integrated to obtain an absolute position. A center of gravity position control means for calculating an attraction force of each magnetic pole for supporting the center of gravity from each magnetic pole from the absolute position information and adjusting an exciting current of each magnetic pole so as to match the calculated value. The non-contact type actuator according to claim 1. 10. The control means holds the gap of each magnetic pole at a predetermined value at the start of control of the mover, detects the exciting current of each magnetic pole in this state, and acts on each magnetic pole from the current value. 10. The non-contact actuator according to claim 9, further comprising means for calculating a suction force and detecting the position of the center of gravity of the mover based on the suction force.