JP2001268960A - Rotation controller for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation controller for motor that is relatively simply constituted and is capable of driving a motor by PWM. SOLUTION: The rotation controller 20 for motor is provided with IC 21 for drive that energizes the driving coil 14 of the motor, a frequency signal generating portion 22 that outputs a frequency signal FG corresponding to the rotation of the motor, and IC 23 for control that controls the IC 14 for drive according to the frequency signal FG. The IC 23 for control is provided with a frequency-voltage conversion circuit 231 that converts the frequency signal FG into a voltage, and a comparator 232 that compares an output voltage F/V from the frequency-voltage conversion circuit 231 with a preset voltage V0. According to a control signal CTL outputted from the comparator 232, the rotation controller switches between state in which a motor current is let through and state in which the motor current is interrupted, and thereby limiter- controls the rotational speed of the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor rotation control device. More specifically, the present invention relates to a motor rotation control device that detects the rotation speed of a motor and controls the rotation speed of the motor based on the detection result.

[0002]

2. Description of the Related Art As a drive control system of a brushless motor, a three-phase 120 ° switching energization system is known. Conventionally, in a motor rotation control device employing this method, a Hall element and a power generation pattern for generating a frequency signal are formed in a portion facing the rotor, and the Hall element and the power generation pattern are generated as the rotor rotates. A change in magnetic pole is detected, and a speed detection signal corresponding to the change is output. Here, a control IC and a drive IC are used as the rotation control device. The control IC detects the timing at which the speed detection signal output from the Hall element and the power generation pattern crosses zero, and detects the current rotation speed. And outputs a control signal to the driving IC based on the monitoring result. As a result, the drive IC controls the motor current level output to the drive coil to rotate the motor at a constant speed.

[0003]

In this type of field, it is widely known that if a PWM system is used for a motor, a regenerative current can be efficiently used and power saving can be achieved. In this method, the driving current level is changed in accordance with the rotation speed of the motor and the motor is rotated at a constant speed, so that such a PWM method cannot be performed.

[0004] In view of such problems, an object of the present invention is to provide a motor rotation control device that can drive a motor by a PWM method with a relatively simple configuration.

[0005]

According to the present invention, there is provided a driving circuit for energizing a driving coil of a motor, frequency signal generating means for outputting a frequency signal corresponding to rotation of the motor, In a motor rotation control device having a control unit for controlling the drive circuit based on a signal, the control unit includes a frequency-voltage conversion unit for converting the frequency signal into a voltage, and a voltage from the frequency-voltage conversion unit. Comparing means for comparing the output with the set voltage, and switching between a state in which the motor is driven and a state in which the driving is stopped by controlling the driving circuit based on a result of comparison by the comparing means. I do.

In the present invention, for example, the control means may switch between a state in which the drive circuit is energized to the drive coil and a state in which the energization is stopped by driving the motor and a state in which the drive is stopped. Switch to.

In the present invention, when the motor rotates, the frequency signal generating means generates a frequency signal corresponding to the rotation of the motor, and this frequency signal is converted into a voltage by the frequency-voltage converting means, and then the frequency signal is converted by the comparing means. Is output to
In this comparing means, the voltage obtained by converting the frequency signal is compared with the set voltage. For example, if it is determined that the voltage is higher than the set voltage, the current motor speed is higher than the target speed. The circuit stops driving the motor. Such a stop is performed until the voltage output from the frequency-voltage conversion means becomes lower than the set voltage in the comparison means. On the other hand, if the comparing means determines that the voltage obtained by converting the frequency signal is lower than the set voltage, the current motor speed is lower than the target speed. Is driven. Such driving is performed in the comparing means until the voltage output from the frequency-voltage converting means becomes higher than the set voltage. Therefore, the motor is switched between a state in which it is driven according to the rotational speed and a state in which the drive is stopped, so that the rotational speed is limited within a certain speed range.

As described above, according to the present invention, the motor is switched between a state in which the drive coil is energized and a state in which the energization is stopped in accordance with the rotational speed.
Since driving can be performed under the same conditions as in the method, power saving can be achieved. In addition, the rotation of the motor can be controlled with a simple circuit configuration using the frequency-voltage conversion means and the comparison means without using a conventional complicated control circuit.

Further, since both the frequency-to-voltage conversion means and the comparison means can be constituted by general circuits, a general-purpose circuit in which both the frequency-to-voltage conversion means and the comparison means are constructed in one semiconductor device. Semiconductor device can be used. In such a configuration, the setting circuit for supplying the set voltage to the semiconductor device may be provided outside the semiconductor device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, with reference to the drawings, a description will be given of a rotation control device of a three-phase motor according to each embodiment to which the present invention is applied. In the rotation control device to which the present invention is applied, the drive circuit and the like are the same as those of the conventional drive IC.
In the following description,
The configuration and operation of the control IC, which is a feature of the present invention, will be mainly described.

FIG. 1 is a configuration diagram of a pump motor to which the present invention is applied. FIG. 2 is a block diagram showing the overall configuration of the motor rotation control device. FIG. 3 is a block diagram showing a configuration of a control IC (control means) used in the rotation control device. FIG. 4 is a graph showing a relationship between a frequency signal and an output voltage in a frequency-voltage conversion circuit (frequency-voltage conversion means) configured in the control IC. FIGS. 5A and 5B show changes in signals output from the frequency-voltage converter and the comparator (comparing means) when the rotation speed of the motor increases in this rotation control device. FIG. 4 is a waveform diagram and a waveform diagram showing a change in a signal output from a frequency-voltage converter and a comparator (comparing means) when the rotation speed of the motor decreases. FIG. 6 is an explanatory diagram showing the waveform of the motor current when the motor is accelerated and decelerated by the rotation control device of the present embodiment.

In FIG. 1, a motor 1 is for a pump, for example, and a rotor 12 is arranged in a motor case 11 in a pump case 101. The rotor 12 has a drive magnet 13. On the bottom side of the pump case 101, a stator 15 having three-phase drive coils 14 is arranged.
, And faces the drive magnet 13 of the rotor 12. The stator 15 is disposed integrally with the motor board 16,
A drive IC 21 and a control IC 23 described later with reference to FIGS. 2 and 3 are mounted on the motor board 16. A cable 17 is connected to the motor board 16. A relay connector 18 is connected to the cable 17, and various power supply voltages and a set voltage V0 described later with reference to FIGS. 2 and 3 are supplied to the motor board 16 via the relay connector 18 and the cable 17. Have been.

In the motor 1 configured as described above, the entire configuration of the rotation control device 2 is generally represented as shown in FIG. In FIG. 2, the rotation control device 20 includes 3
A driving IC 21 having a driving circuit for supplying a motor current to the phase driving coils 14 (W, V, U); a frequency signal generator 22 for outputting a frequency signal FG corresponding to the rotation of the motor; Driving IC 21 based on signal FG
And a control IC 23 for controlling the control. Also,
The motor rotation control device 20 includes a setting circuit 24 that outputs a set voltage V0 corresponding to the target speed.

In this embodiment, the frequency signal generator 22
Detects, for example, a change in magnetic pole accompanying rotation of the rotor at a position facing the rotor, and outputs a corresponding frequency signal F
G is output. In the present embodiment, the signal generated by the power generation pattern 221 for generating a frequency signal is converted into a pulse signal (frequency signal FG) as described later with reference to FIGS. 5A and 5B in the driving IC 21. Later, control IC2
Output to 3. The input section of the frequency signal FG to the driving IC 21, the common wiring COM to the driving coil 14,
Various electric elements such as resistors, capacitors, diodes and the like are connected to the wirings for the respective drive coils 14 as necessary. Omitted.

As shown in FIG. 3, the control IC 23 includes:
The frequency signal F generated by the frequency signal generator 22 described above.
A frequency-voltage conversion circuit 231 for converting G into a voltage and a comparator 232 for comparing a voltage output from the frequency-voltage conversion circuit 231 with a set voltage V0 are configured. Here, the setting voltage V0 output from the setting circuit 24 and the output voltage F / V of the frequency-voltage conversion circuit 231 are input to the comparator 232, and the output from the comparator 232 is used as the control signal CTL. It is output to the driving IC 21.
In the present embodiment, the setting circuit 24 has a configuration in which the DC voltage of +5 V is divided by the resistors 241 and 242. It should be noted that, for the control IC 23, if necessary,
Various electric elements such as a resistor and a capacitor are connected to the circuit, but the electric symbols are shown in the drawings, and the description is omitted.

In addition, as shown in FIG. 4, the frequency-voltage conversion circuit 231 has three types of frequency-voltage conversion circuits. As shown in FIG. The output voltage F / V has a characteristic of increasing linearly.

In the rotation control device 20 configured as described above, when the control signal CTL is at a high logic level, the drive IC 21 applies a motor current to the drive coil 14 to drive the motor, When CTL is at the low logic level, the motor current is stopped from being supplied to the drive coil 14 to stop driving the motor.

Therefore, as shown in FIG. 5A, while the motor is accelerating, the frequency of the frequency signal FG rises, so that the voltage level of the output signal F / V from the frequency-voltage conversion circuit 231 changes. Going up. Where frequency-
When the level of the output voltage F / V from the voltage conversion circuit 231 is lower than the set voltage V0, the voltage of the control signal CTL output from the comparator 232 is at a high logic level.
A constant motor current is continuously output from the drive IC 21 to the drive coil 14. Therefore, while the motor is being driven, the rotation speed of the motor increases.

However, when the level of the output voltage F / V from the frequency-voltage conversion circuit 231 becomes higher than the set voltage V0, the voltage of the control signal CTL output from the comparator 232 becomes a low logic level. Then, the supply of the motor current from the driving IC 21 to the driving coil 14 is stopped.
As a result, the driving of the motor is stopped, and thereafter, FIG.
As shown in (B), the rotation speed of the motor decreases.

During the deceleration of such a motor, FIG.
As shown in (4), the frequency of the frequency signal FG decreases, so that the level of the output voltage F / V from the frequency-voltage conversion circuit 231 decreases. While the level of the output voltage F / V from the frequency-voltage conversion circuit 231 is higher than the set voltage V0, the voltage of the control signal CTL output from the comparator 232 is at a low logic level. Then, the supply of the motor current to the drive coil 14 is stopped. However, when the level of the output voltage F / V from the frequency-voltage conversion circuit 231 becomes lower than the set voltage V0, the control signal CT output from the comparator 232
Since the voltage of L becomes the high logic level, the supply of the motor current from the driving IC 21 to the driving coil 14 is restarted. Therefore, since the driving of the motor is restarted, FIG.
As shown in (A), the rotation speed of the motor increases.

As described above, the motor rotation control device 20 according to the present embodiment generates the frequency signal FG corresponding to the rotation of the motor, converts the frequency signal FG into a voltage, and then generates the frequency signal FG and the set voltage V0. Are switched between a state in which the motor is driven (energized state) and a state in which the drive is stopped (state in which energization is stopped) according to the level. Therefore, the rotation speed of the motor is controlled to a limit within a certain range. Therefore, in the present embodiment, as shown in FIG. 6, driving is performed under the same conditions as in the PWM method in which the state is switched between the energized state and the energized state, and power saving can be achieved. Moreover, the frequency-voltage conversion circuit 231 and the comparator 2 can be used without using a conventional complicated control circuit.
It is possible to control the rotation of the motor with a simple circuit configuration using the H.32, and if the frequency-voltage conversion circuit 231 and the comparator 232 are used, both can be configured by a general circuit. Therefore, a general-purpose IC in which both circuits are configured in one IC can be used as the control IC 23.

If a hysteresis comparator is used as the comparator 232, hunting can be prevented. Further, the frequency signal FG may use an FG magnet or a signal using an FG circuit pattern.

[0023]

As described above, in the motor rotation control device according to the present invention, the frequency signal generating means generates a frequency signal corresponding to the rotation of the motor, and the frequency signal is converted into the voltage by the frequency-voltage converting means. After the conversion, this voltage is compared with the set voltage by the comparing means,
The state where the motor is driven by the height (powered state)
And a state in which driving is stopped (a state in which energization is stopped). Therefore, the rotation speed of the motor is controlled within a certain range. Further, since the motor is driven in the same manner as when driven by the PWM method, power saving can be achieved. In addition, the rotation of the motor can be controlled with a simple circuit configuration using a frequency-voltage conversion circuit and a comparator without using a conventional complicated control circuit, and the frequency-voltage conversion circuit and the comparator can be controlled. In this case, since all of them can be configured by a general circuit, a general-purpose IC in which both circuits are configured in one IC can be used as a control IC.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a pump motor to which the present invention is applied.

FIG. 2 is a block diagram showing an overall configuration of a motor rotation control device to which the present invention is applied.

FIG. 3 is a control IC used in the rotation control device shown in FIG. 2;
FIG. 3 is a block diagram illustrating a configuration of (control means).

FIG. 4 is a graph showing a relationship between a frequency signal and an output voltage in a frequency-voltage conversion circuit (frequency-voltage conversion means) configured in the control IC shown in FIG. 3;

FIGS. 5A and 5B are diagrams respectively showing a case where a frequency-voltage conversion unit and a comparator (comparing means) are used when the rotation speed of the motor increases in the motor rotation control device to which the present invention is applied. A waveform diagram showing changes in the output signal,
FIG. 6 is a waveform diagram showing changes in signals output from a frequency-voltage conversion unit and a comparator (comparing means) when the rotation speed of the motor decreases.

FIG. 6 is an explanatory diagram showing a waveform of a motor current when the motor is accelerated and decelerated by the rotation control device to which the present invention is applied.

[Explanation of symbols]

Reference Signs List 1 motor 11 motor case 12 rotor 13 drive magnet 14 drive coil 15 stator 16 motor board 21 drive IC (drive circuit) 22 frequency signal generator (frequency signal generator) 23 control IC (control means) 24 setting circuit 221 frequency Power generation pattern for signal generation 231 Frequency-voltage conversion circuit (frequency-voltage conversion means) 232 Comparator (comparison means) CTL control signal FG frequency signal F / V Output voltage of frequency-voltage conversion circuit V0 Set voltage

Claims (3)

[Claims] 1. A drive circuit for energizing a drive coil of a motor, frequency signal generating means for outputting a frequency signal according to rotation of the motor, and control means for controlling the drive circuit based on the frequency signal. In the rotation control device for a motor having, the control means includes a frequency-voltage conversion means for converting the frequency signal into a voltage, and a comparison means for comparing a voltage output from the frequency-voltage conversion means with a set voltage, A rotation control device for a motor, wherein the control circuit controls the drive circuit based on the comparison result by the comparison means to switch between a state in which the motor is driven and a state in which the drive is stopped. 2. The control device according to claim 1, wherein the control unit switches between a state in which the drive circuit energizes the drive coil and a state in which the energization is stopped, thereby switching the state in which the motor is driven and the drive. A motor rotation control device for switching to a stopped state. 3. The semiconductor device according to claim 1, wherein the frequency-voltage conversion unit and the comparison unit are configured in one semiconductor device, and the setting circuit that supplies the set voltage to the semiconductor device is the semiconductor device. A rotation control device for a motor, wherein the rotation control device is configured outside the motor.