JPH10336990A - Oscillatory motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oscillatory motor in which positional control can be performed accurately regardless of temperature variation in the working environment while minimizing the total manufacturing cost. SOLUTION: The oscillatory motor comprises a rotor 3 and fixed coils 4, 5 for oscillating the rotor 3. A magnetic sensor SH1 is disposed in the circumferential center of the fixed coil 4 at a lower part on the outside thereof and a magnetic sensor SH2 having detection characteristics similar to those of the magnetic sensor SH1 is disposed while being spaced apart by an angle θtherefrom in the circumferential direction. A temperature correction circuit determines the difference of output voltage from both magnetic sensor and corrects the output voltage from the magnetic sensor SH1 based on the difference thus determined. A control circuit compares the correction voltage with a target value and controls conduction of the fixed coils 4, 5 such that the output voltages are matched each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing motor capable of controlling the rotation angle of a rotor within a predetermined range.

[0002]

2. Description of the Related Art Conventionally, a rocking motor of this type is known as shown in FIG. The oscillating motor includes a rotor 3 rotatably supported by bearings 1 and 2, and fixed coils 4, 5, which are arranged around the rotor 3 with an air gap therebetween and include air-core coils for oscillating the rotor 3. It is composed of The rotor 3 includes a shaft 6 and two magnets 7 and 8 attached to the shaft 6, and both ends of the shaft 6 are rotatably supported by bearings 1 and 2. The fixed coils 4 and 5 are arranged around the magnets 7 and 8 so that the magnetic flux is directed toward the center of the rotor 3. Since the fixed coils 4 and 5 are arranged along the circumferential direction of the outer peripheral surfaces of the magnets 7 and 8 each having a cylindrical shape as a whole, they are each formed in an arc shape as shown in FIG. Fixed coil 4
As shown in FIG. 6, a magnetic sensor SH for detecting the positions of the magnets 7 and 8 (rotation angle of the rotor 1)
1 is arranged. The magnetic sensor SH1 includes a Hall element that converts a magnetic flux into a voltage. The detection voltage of the magnetic sensor SH1 is supplied to the control circuit 10, as shown in FIG. The control circuit 10 includes the fixed coil 4
And a coil drive circuit 12 for driving the fixed coil 5 are connected.

[0003] Next, the operation of the conventional rocking motor configured as described above will be described. Now, the magnetic sensor SH1
Is input to the control circuit 10, the control circuit 1
0 compares the detected voltage with a target voltage corresponding to the target position of the rotor 3 and controls the coil drive circuits 11 and 12 so that the detected voltage matches the target voltage. That is,
The control circuit 10 outputs to the coil drive circuits 11 and 12 a command value such that the detected voltage matches the target voltage. Then, the coil drive circuits 11 and 12 supply a drive current according to the command value to the fixed coils 4 and 5. As a result, torque is generated in the magnets 7 and 8, and the rotor 3 rotates, and the rotor 3 is positioned at the target position.

[0004]

As described above, in the conventional oscillating motor, the position of the rotor 3 is detected by one magnetic sensor SH1 composed of a Hall element, and the detected position is corrected by a change in environmental temperature. Did not. For this reason, in the conventional swing motor, when the temperature of the use environment changes, the characteristics of the magnets 7 and 8 and the magnetic sensor SH1 change, and it is not possible to detect the accurate position of the rotor 3 from the detection voltage of the magnetic sensor SH1. is there. Therefore, in order to correct such inconvenience, a temperature sensor is separately arranged near the oscillating motor, and the detection position of the rotor 3 (correction of the detection voltage of the magnetic sensor) is corrected based on the temperature detected by the temperature sensor. Techniques for performing are known. However, when the temperature sensor is arranged near the rocking motor and the correction is performed in this way, there is a difference between the temperature inside the rocking motor and the environmental temperature.
However, there is a problem that the accuracy of the correction of the detection position is low, and the production cost increases because the temperature sensor is separately arranged.

Accordingly, an object of the present invention is to provide a rocking motor capable of performing high-precision position control even when there is a temperature change in a use environment and minimizing the overall manufacturing cost. And

[0006]

In order to achieve this object, the present invention provides a magnet 7, comprising at least two poles in the radial direction.
8 and a rotatable rotor 3, and coils (fixed coils 4 and 5, a rotor 3) for swinging a rotor having at least two rotors arranged at predetermined intervals around the rotor 3 with a gap therebetween. A first sensor (magnetic sensor SH1) that is disposed around and detects the position of the rotor, and a second sensor (magnetic sensor SH1) that is disposed at a position circumferentially away from the position where the first sensor is disposed and detects the position of the rotor 3. A magnetic sensor SH2), and a correction means (temperature correction circuit 21) for calculating the difference between the detection value of the first sensor and the detection value of the second sensor at an arbitrary temperature to correct the detection value of the first sensor. , So that the correction detection value corrected by the correction means becomes the target position of the rotor 3.
Control means (control circuit 1) for controlling the current supplied to the coil;
0). As described above, in the present invention, in addition to the first sensor, the second sensor having the same function as the first sensor is provided, and the difference between the detection values of the two sensors is arithmetically processed to correct the temperature of the detection value of the first sensor. I did it. Therefore, according to the present invention, the position can be controlled with high accuracy even when the temperature of the use environment changes, and the overall manufacturing cost can be minimized.

Further, the present invention has a magnet having at least two poles in a radial direction, a rotatable rotor, and at least two magnets spaced around the rotor by a predetermined distance from the magnet with a gap therebetween. A coil for oscillating the rotor arranged in
A first sensor disposed around the rotor to detect the position of the rotor, control means for controlling a current supplied to the coil so that a value detected by the first sensor is a target position of the rotor, and a first sensor And a second sensor that is disposed at a position circumferentially distant from the arrangement position of the second sensor and detects a position of the rotor, and calculates a difference between a value detected by the first sensor and a value of the second sensor at an arbitrary temperature. And a correcting means for correcting the target value. As described above, in the present invention, in addition to the first sensor, the second sensor having the same function as the first sensor is provided, and the difference between the detection values of the two sensors is calculated, and the control means uses the target for the control. The value was corrected for temperature. For this reason, according to the present invention, high-precision position control can be performed even when there is a temperature change in the use environment, and the overall manufacturing cost can be minimized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a swing motor according to this embodiment. FIG. 2 is a block diagram showing an electrical configuration of this embodiment. FIG. 3 is a block diagram showing a detailed configuration of the temperature compensation circuit. In the swing motor according to this embodiment, FIG.
As shown in FIG. 3, the magnetic sensor SH
1 is arranged. Further, a magnetic sensor SH2 for temperature correction is arranged at a position separated by an angle θ in the circumferential direction from the arrangement position of the magnetic sensor SH1. Magnetic sensor S
H1 and the magnetic sensor SH2 are, for example, Hall sensors that output a voltage corresponding to the strength of the magnetic flux of the magnets 7 and 8,
As shown in FIG. 5, the output characteristics (detection characteristics) are the same, and the detection characteristics change depending on the temperature of the use environment. The other configuration of the mechanical portion of this embodiment is the same as that of the conventional device shown in FIG. 6, and therefore, the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

As shown in FIG. 2, when an output voltage of the magnetic sensor SH1 and an output voltage of the magnetic sensor SH2 are input, a difference between the two voltages is obtained. A temperature correction circuit 21 that corrects the temperature of the output voltage of the magnetic sensor SH1 based on the difference is provided. The voltage corrected by the temperature correction circuit 21 is input to the control circuit 10. The control circuit 10 includes:
A coil drive circuit 11 for supplying a drive current to the fixed coil 4,
A coil drive circuit 12 that supplies a drive current to the fixed coil 5 is connected.

Next, a detailed configuration of the temperature correction circuit 21 will be described with reference to FIG. This temperature compensation circuit 21
Is composed of a subtractor 23, a divider 24, and a K-times amplifier 25, as shown in FIG. The subtractor 23 subtracts (subtracts) the output voltage V0 of the magnetic sensor SH1 from the output voltage V2 of the magnetic sensor SH2. The divider 24 subtracts the output voltage V0 of the magnetic sensor 23 from the output value (V2
−V0) to obtain V0 / (V2−V0). The K-times amplifier 25 outputs the output value V0 /
(V2−V0) is multiplied by K, and the correction voltage value V1 = V0 × K /
(V2−V0) is obtained. The details of the operations of these units will be described later.

Next, the operation of the embodiment having such a configuration will be described with reference to the drawings. When the output voltage of the magnetic sensor SH1 and the output voltage of the magnetic sensor SH2 are input to the temperature correction circuit 21, the temperature correction circuit 21
The difference between the two voltages is determined, and the temperature of the output voltage of the magnetic sensor SH1 is corrected based on the determined difference. That is, the temperature correction circuit 21 corrects the temperature of the output voltage of the magnetic sensor SH1 according to the temperature change of the usage environment at that time, and outputs the corrected voltage to the control circuit 10. Control circuit 10
Compares the input correction voltage with a target voltage corresponding to a target position of the rotor 3 and controls the coil drive circuits 11 and 12 so that the correction voltage matches the target voltage. That is, the control circuit 10 outputs to the coil drive circuits 11 and 12 a command value such that the correction voltage matches the target voltage. Then, the coil drive circuits 11 and 12 supply a drive current according to the command value to the fixed coils 4 and 5. As a result, torque is generated in the magnets 7 and 8, and the rotor 3 rotates, and the rotor 3 is positioned at the target position.

Next, the temperature correction of the temperature correction circuit 21 will be described with reference to FIGS. In this description,
The magnetic sensor SH1 and the magnetic sensor SH2 have the same detection characteristics (output characteristics) as shown in FIG. A straight line A in FIG. 5 shows detection characteristics when the temperature of the use environment is a normal temperature (for example, 20 ° C.), and a straight line B in FIG.
Indicates detection characteristics when the temperature of the use environment is abnormal (for example, 80 ° C.). Now, as shown in FIG. 4, if the magnets 7 and 8 are in a position rotated clockwise by an angle φ1 from the reference position and the temperature of the use environment is 80 ° C.,
The output voltage of the magnetic sensor SH1 becomes V0 as shown in FIG. 5, and the output voltage of the magnetic sensor SH2 becomes V2 as shown in FIG. Here, the control circuit 10 is configured to perform control using the output voltage of the magnetic sensor SH1 when the temperature of the use environment is the normal temperature (20 ° C.). Therefore, the voltage required for control of the control circuit 10 is the voltage V1 at the time of normal temperature (20 ° C.). This voltage V1
Is the output voltage V0 of the magnetic sensor SH1 and the magnetic sensor S when the temperature of the use environment is abnormal (for example, 80 ° C.).
Since it is obtained from the output voltage V2 of H2, how to obtain it will be described with reference to FIG.

Now, in FIG. 5, when considering a right triangle abc having the straight line B as the hypotenuse, the base ab has a constant value even if the gradient of the straight line B changes. This is the magnetic sensor SH1
And the magnetic sensor SH2 are physically fixed at an angle θ. On the other hand, since the gradient of the straight line B changes depending on the use environment temperature, the length of the vertical side bc of the right triangle abc changes according to this change, and this length is the difference between the output voltage V2 and the output voltage V0 ( V2−V0). Next, considering a right triangle efg having the straight line A as a hypotenuse, the base ef is equal to the length of the base ab of the right triangle abc. On the other hand, since the gradient of the straight line A is known,
The length of the vertical side fg of the right triangle efg can be set to K with a constant value. From the above, the triangle oha and the triangle ab
c has a similar shape, and the triangle ohe and the triangle efg have a similar shape. Therefore, the following equation (1) holds. K / (V2−V0) = V1 / V0 (1) When this equation (1) is obtained for V1, the following equation (2) is obtained. V1 = V0 × K / (V2-V0) (2)

Therefore, the temperature correction circuit 21 shown in FIG. 3 performs an arithmetic process for obtaining the correction voltage V1 of the equation (2) based on the output voltage V0 of the magnetic sensor SH1 and the output voltage V2 of the magnetic sensor SH2. That is, the subtractor 23 subtracts the output voltage V0 of the magnetic sensor SH1 from the output voltage V2 of the magnetic sensor SH2, and the subtraction value (V2−V0).
Is output. Next, the divider 24 controls the magnetic sensor SH1
Is divided by its subtracted value (V2−V0),
The divided value V0 / (V2−V0) is output. The K-times amplifier 25 multiplies the division value V0 / (V2-V0) by K,
The correction voltage V1 = V0 × K / (V2−V0) is set to the control circuit 1
Output to 0.

As described above, in this embodiment, a magnetic sensor SH2 for temperature correction is provided in addition to the magnetic sensor SH1 similar to the conventional one, and the temperature correction circuit 21 obtains the difference between the two output voltages. The temperature of the output voltage of the magnetic sensor SH1 is corrected in accordance with the condition (1), so that high-precision position control can be performed even when the temperature of the use environment changes. Further, in this embodiment, it is not necessary to separately provide a temperature sensor for temperature correction, and only the magnetic sensor SH2 similar to the conventional magnetic sensor SH1 composed of a Hall sensor needs to be added. Can be minimized.
Further, in this embodiment, the additional magnetic sensor SH
2 is composed of a Hall sensor and is small, so that there is an advantage that the size of the swing motor can be maintained at the same size as the conventional one.

In the above embodiment, the magnetic sensor SH1
The case has been described in which the output voltage V0 is temperature-corrected by the temperature correction circuit 21 and the temperature-corrected voltage V1 is input to the control circuit 10. However, the present invention provides a magnetic sensor SH1.
Is directly input to the control circuit 10 without temperature correction, and the target voltage VS corresponding to the target position of the rotor 3 of the control circuit 10 is output from the output voltage V0 of the magnetic sensor SH1.
And the output voltage V2 of the magnetic sensor SH2. In this case, the temperature correction circuit obtains a difference (V2−V0) between the output voltage V0 of the magnetic sensor SH1 and the output voltage V2 of the magnetic sensor SH2, and divides the difference (V2−V0) by the above K. (V2-V0)
/ K is calculated, and the calculated value (V2-
V0) / K.

[0017]

As described above, according to the present invention, the first
A second sensor having the same function as the first sensor is provided in addition to the sensor, a difference between the detection positions of the two sensors is obtained, and the detection position of the first sensor is temperature-corrected based on the obtained difference. For this reason, according to the present invention, high-precision position control can be performed even when there is a temperature change in the use environment, and the overall manufacturing cost can be minimized.

In the present invention, in addition to the first sensor, the first sensor
A second sensor having the same function as the sensor is provided, a difference between the detection positions of the two sensors is obtained, and the target position used by the control means for control is temperature-corrected based on the obtained difference. For this reason, according to the present invention, high-precision position control can be performed even when there is a temperature change in the use environment, and the overall manufacturing cost can be minimized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a mechanical configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of the embodiment.

FIG. 3 is a block diagram illustrating a configuration of a temperature correction circuit.

FIG. 4 is an explanatory diagram illustrating an arrangement relationship between a rotor and a magnetic sensor.

FIG. 5 is a diagram illustrating an example of detection characteristics of a magnetic sensor and explaining temperature correction.

FIG. 6 is a perspective view of a conventional device.

FIG. 7 is a block diagram of a conventional device.

[Explanation of symbols]

 SH1, SH2 Magnetic sensor 3 Rotor 4, 5 Fixed coil 7, 8 Magnet 10 Control circuit 11, 12 Coil drive circuit 21 Temperature correction circuit 23 Subtractor 24 Divider 25 K amplifier

Claims (2)

[Claims] 1. A rotor having a magnet having at least two poles in a radial direction, and a coil for oscillating a rotor having at least two magnets arranged at predetermined intervals relative to the magnet with an air gap around the rotor. A first sensor arranged around the rotor and detecting the position of the rotor; and a second sensor arranged at a position circumferentially distant from the arrangement position of the first sensor and detecting the position of the rotor. The detection value of the first sensor at an arbitrary temperature and the second sensor
Correction means for calculating the difference between the detection value of the sensor and the temperature of the detection value of the first sensor, and the coil so that the correction detection value corrected by the correction means becomes a target position of the rotor. And a control means for controlling a current supplied to the oscillating motor. 2. A rotor having a magnet having at least two poles in a radial direction, and a coil for oscillating a rotor having at least two magnets arranged at predetermined intervals relative to the magnet with an air gap around the rotor. A first sensor arranged around the rotor and detecting the position of the rotor; and a current supplied to the coil so that a detection value of the first sensor becomes a target position (command position) of the rotor. Control means for controlling; a second sensor arranged in a circumferential direction apart from an arrangement position of the first sensor to detect a position of the rotor; a detection value of the first sensor at an arbitrary temperature; 2
And a correcting means for calculating the difference between the detected value and the sensor value to correct the target value (command value).