JP2007306752A - Motor drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive device wherein speed command voltage for a motor can be supplied externally and speed control can be stabilized over a wide range. <P>SOLUTION: The motor drive device includes a waveform generating means 31, incorporated in or integrated with a motor 1 having a moving member and three-phase drive windings for generating a waveform signal for driving the motor 1 with phase timing, based on a moving member position detection signal; a drive means 32 for supplying the three-phase drive windings with drive voltage or drive current, based on the waveform signal; and a motor control terminal 10, to which a control signal Vsp is inputted. The control signal Vsp is inputted from equipment 6 where the motor is to be mounted, and servo computation for controlling the speed of the motor 1 to a desired value is carried out by the equipment 6 mounted with the motor. The control signal Vsp is a signal, based on the result of servo computation carried out by the equipment 6 mounted with the motor, and the magnitude of the drive voltage or drive current for the three-phase drive windings from the drive means 32 can be controlled by the control signal Vsp. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor driving device used in a printer, a copying machine, a scanner, a fax machine, or a combination of these equipped with a paper feed motor, a scanner motor or the like in a driving system.

  In recent years, motors used in printers, copiers, scanners, fax machines, or composite devices thereof have become uneven in response to a wide range of rotational speed requirements of the motors as the functions of the devices become more advanced and multifunctional. Improvements in accuracy and responsiveness at startup have been strongly desired.

  In motor drive systems, PWM (pulse width modulation) has generally been used to drive the motor at a variable speed. PWM is a method of controlling the amount of power supplied to the motor by changing the ratio of the on time and off time of the transistor connected to the drive winding of the motor. As a result, the PWM can drive the motor at a variable speed, and has recently been used for driving a motor used in the above-described printer, copier, scanner, fax machine, or a composite device thereof. .

  Various types of motor drive devices mounted on these devices have been proposed in the past, such as the one shown in FIG.

  2 includes a motor 100, three-phase drive windings 110, 130, and 150, and an inverter 200 connected to the three-phase drive windings 110, 130, and 150. The inverter 200 includes power transistors 210, 220, and 230. , 240, 250, 260. Further, the ratio of ON / OFF switching time of the power transistors 210, 220, 230, 240, 250, 260 is controlled by PWM, and the motor driving means 300 for controlling the amount of power supplied to the motor 100, and the rotation of the motor 100 The rotational speed detection 400 for detecting the speed, the FG signal having a frequency proportional to the rotational speed of the motor 100 output from the rotational speed detection 400, and the speed reference signal to the motor 100 are input, and the speed error signal is output. A rotation speed error detection 700 and an error amplifier 800 that amplifies the speed error signal output from the rotation speed error detection 700 are provided. The inverter 200, the motor driving means 300, the rotation speed detection 400, and the rotation speed error detection 700 are provided. The error amplifier 800 is built in the motor 100 having the three-phase drive windings 110, 130, and 150. Is a motor driving apparatus that is configured on a printed circuit board 900 are integrated.

  The three-phase drive windings 110, 130, and 150 of the motor 100 are connected to the power transistors 210, 220, 230, 240, 250, and 260 of the inverter 200, and the rotation speed detection 400 detects the rotation speed of the motor 100 and rotates the rotation. An FG signal having a frequency proportional to the speed is output. The rotation speed error detection 700 receives an FG signal and a speed reference signal as a command signal for a desired set rotation speed, and an output thereof is connected to an input of the error amplifier 800. The output of the error amplifier 800 is connected to the input of the motor driving means 300, and the output of the motor driving means 300 is connected to the inverter 200 power transistors 210, 220, 230, 240, 250, 260.

  Next, a driving method of the motor driving device in FIG. 2 will be described below.

The rotational speed of the motor 100 is detected by the rotational speed detection 400, and the rotational speed detection 400 outputs an FG signal having a frequency proportional to the rotational speed of the motor 100 to the rotational speed error detection 700. The rotation speed error detection 700 detects a speed error by comparing the FG signal output from the rotation speed detection 400 with a speed reference signal serving as a command signal for a desired set rotation speed, and outputs a speed error signal. The error amplifier 800 receives the speed error signal output from the rotational speed error detection 700 and outputs a voltage command Vsp, which is a motor drive control command amplified by the error amplifier 800, to the motor drive means 300. The motor driving means 300 outputs an on / off switching control command to the gate electrodes of the power transistors 210, 220, 230, 240, 250, 260 of the inverter 200 according to the voltage command Vsp by PWM. As a result, power corresponding to the magnitude of the voltage command Vsp is also supplied to the three-phase drive windings 110, 130, and 150 of the motor 100, and the motor is controlled to have a predetermined rotational speed (see, for example, Patent Document 1). ).
JP-A-8-266078

    However, when the motor driving device according to the prior art includes an error amplifier having a circuit configuration as shown in FIG. 3, when the motor is used at a variable speed, depending on the command rotational speed, sufficient accuracy such as rotational unevenness may be obtained. Speed characteristics may not be obtained.

  First, the circuit configuration of the error amplifier of FIG. 3 will be described.

  In the error amplifier of FIG. 3, reference numeral 70 denotes an amplifier, and one of its inputs is connected to a bias power supply 71. Resistors 72, 73, 74 and a capacitor 75 are connected to the other input. A capacitor 76 is connected in series with the resistor 72, and the other end of the capacitor 76 is connected to the output of the amplifier 70. The capacitor 75 is connected in parallel to the resistor 72 and the capacitor 76 connected in series.

  A speed error signal terminal or a phase error signal terminal, which is an input terminal of the error amplifier in FIG. 3, is a terminal to which a signal output from the rotation speed error detection 700 in FIG. 2 is input. (The phase error signal terminal is used to detect the phase error of the motor and perform phase control.) The error signal input to the terminal depends on the speed error between the FG signal and the speed reference signal or the amount of phase error. This is a pulse signal for an acceleration or deceleration command of a wide range, and is detected for each cycle of the FG signal. The pulse signal of the acceleration / deceleration signal is a pulse signal having a reverse polarity with respect to the reference voltage Vref of the amplifier 70 determined by the bias power supply 71.

  3 outputs a voltage command Vsp for controlling the amount of power supplied to the motor 100, and the output is input to the motor driving means 300 in FIG.

  3, the resistors 72, 73 and 74 are resistors for setting an error amplification factor, the capacitor 76 is an integrating capacitor, and the capacitor 75 is a high-pass filter capacitor. is there. These circuit constants are related to speed control, and affect the stability of the rotational speed, such as the starting characteristics of the motor or the accuracy of rotation unevenness.

  That is, in order to stabilize the rotation speed of the motor, it is necessary to appropriately set the circuit constants of the resistors 72, 73, 74 and the capacitors 75, 76. However, in order to set the circuit constant so that the stabilization of the rotation speed is optimum, the circuit constant must be appropriately changed according to conditions such as the motor specifications and the rotation speed.

In the motor drive device of FIG. 2 having the error amplifier of FIG. 3, if the rotational speed to be used is a constant and fixed rotational speed, the error amplifier resistors 72, so that the speed characteristics are optimized at the rotational speed. The circuit constants 73 and 74 and capacitors 75 and 76 can be designed. However, when the speed is controlled by changing the rotational speed with the same motor drive device, the error amplifier circuit constants are not set so that the speed characteristics are optimized at the rotational speed, so the accuracy of rotational unevenness etc. May have declined.

  Therefore, when the motor is used with the rotation speed changed in the motor driving apparatus shown in FIG. 2 having the error amplifier shown in FIG. 3, the circuit constants of the error amplifier should be designed so as to improve the rotation unevenness accuracy at high speed rotation, for example. For example, if the circuit constant of the error amplifier is designed so that the rotation unevenness accuracy is reduced at low speed rotation and the rotation unevenness accuracy is improved at low speed rotation, the rotation unevenness accuracy may not be optimal at high speed rotation.

  In addition, in order to support multiple command rotation speeds, it has multiple error amplifiers designed with circuit constants so that the speed characteristics are optimized at each rotation speed, and an appropriate error amplifier is selected according to the command rotation speed. By doing so, there is a method for obtaining a stable speed characteristic even at a variable speed, but the circuit scale becomes large, leading to an increase in the number of elements, and an increase in cost.

  In order to solve the above-mentioned problems, a motor driving device of the present invention is built in or integrated in a motor having a mover and a three-phase drive winding, and a waveform signal for driving the motor is used as a position detection signal of the mover. Waveform generating means for generating at a phase timing based on, a drive means for supplying a drive voltage or drive current to the three-phase drive winding based on the waveform signal, and a motor control terminal to which a control signal is input, The control signal is input from a device on which the motor is mounted, the servo calculation for controlling the speed of the motor to a desired value is performed by the device, and the control signal is a signal based on the result of the servo calculation performed by the device. And the magnitude of the drive voltage or drive current of the three-phase drive winding by the drive means can be controlled by the control signal.

  According to the motor driving device of the present invention, the motor control device has a motor control terminal to which a signal serving as a control command for the drive voltage or drive current of the three-phase drive winding is input from the device on which the motor is mounted to the drive means. I am doing.

  This enables stable speed control even over a wide range of rotational speeds by inputting a signal that is a control command for the magnitude of the drive voltage or drive current of the three-phase drive winding from the device on which the motor is mounted. Since variable speed can be achieved even without control, motor control with a higher degree of freedom is possible.

  Furthermore, the number of elements can be reduced by omitting the motor speed control function such as rotational speed error detection and error amplifier from the motor drive device, leading to cost reduction of the motor drive device.

  The motor drive device of the present invention is built in or integrated with a motor having a mover and a three-phase drive winding, and generates a waveform signal for driving the motor at a phase timing based on a position detection signal of the mover. Waveform generation means, drive means for supplying a drive voltage or drive current to the three-phase drive winding based on the waveform signal, and a motor control terminal to which a control signal is input, the control signal being mounted on the motor The servo calculation for controlling the motor speed to a desired value is performed by the device, and the control signal is a signal based on the result of the servo calculation performed by the device. The drive means or the drive current of the three-phase drive winding can be controlled by the drive means.

  This enables stable speed control even over a wide range of rotational speeds by inputting a signal that is a control command for the magnitude of the drive voltage or drive current of the three-phase drive winding from the device on which the motor is mounted. Since variable speed can be achieved even without control, motor control with a higher degree of freedom is possible.

  Furthermore, the number of elements can be reduced by omitting the motor speed control function such as rotational speed error detection and error amplifier from the motor drive device, leading to cost reduction of the motor drive device.

  FIG. 1 is a schematic view of a motor drive device of the present invention.

  In FIG. 1, the three-phase drive windings 11, 13, and 15 of the motor 1 are connected to an inverter 20. The inverter 20 includes power transistors 21, 22, 23, 24, 25, and 26. The power transistors 21 and 22 are connected in series between the power supply terminals of the DC power supply 5, and the series connection point is connected to the drive winding 11 of the motor 1. Connecting. Similarly, the power transistors 23 and 24 are connected in series between the power supply terminals of the DC power supply 5, the series connection point is connected to the drive winding 13 of the motor 1, and the power transistors 25 and 26 are connected between the power supply terminals of the DC power supply 5. The series connection point is connected to the drive winding 15 of the motor 1. The rotational speed detection 4 for detecting the rotational speed of the motor 1 generates an FG signal having a frequency proportional to the rotational speed of the motor 1 and is a servo arithmetic unit for controlling the speed of the motor provided in the device 6 on which the motor is mounted. Connect to terminal 9 which is the output terminal to 60. The terminal 10 is used to control the speed of the motor provided in the device 6 on which the motor is mounted, with the voltage command Vsp serving as a control command for the magnitude of the drive voltage applied to the three-phase drive windings 11, 13, 15 of the motor 1. It is a terminal that is input from the servo arithmetic unit 60 that controls the motor, and is connected to the motor driving means 30. The motor drive means 30 comprises a waveform generation means 31 and a PWM 32 for generating a control command for supplying a drive voltage to the three-phase drive windings 11, 13 and 15. The waveform generation means 32 receives a CS signal that is a rotational position detection signal of the motor 1 and outputs a WF signal that is a waveform generation signal. The PWM 32 receives the WF signal and the voltage command Vsp from the servo arithmetic unit 60 that controls the speed of the motor provided in the device 6 on which the motor is mounted, and receives power transistors 21, 22, 23, 24, 25, A control signal is output to 26 gate electrodes. Further, the inverter 20, the motor driving means 30, and the rotation speed detection 4 are configured on a printed circuit board 2 built in or integrated in the motor 1, and are formed of a monolithic integrated circuit.

  In the motor driving device configured as described above, a specific driving method will be described below.

In FIG. 1, in order to drive the motor 1, a voltage command Vsp serving as a control command for the magnitude of the drive voltage to the three-phase drive windings 11, 13, 15 is provided in the device 6 on which the motor is mounted. It is input to the motor drive means 30 through the input terminal 10 from the servo calculator 60 that controls the motor speed control. Here, the servo calculator 60 has a servo calculation function for controlling the motor speed to a desired value, and the voltage command Vsp is a signal based on the result of the servo calculation. The motor driving unit 30 includes a waveform generation unit 31 and a PWM 32. The waveform generation unit 31 generates a waveform generation signal at a phase timing based on a CS signal that is a position detection signal of the motor 1. The PWM 32 is based on the WF signal generated by the waveform generating means 31 and the voltage command Vsp input from the servo calculator 60 that controls the speed of the motor provided in the device 6 on which the motor is mounted. A control command is output to the gate electrodes of the transistors 21, 22, 23, 24, 25, and 26, a drive voltage is supplied to the three-phase drive winding, and the rotation speed of the motor 1 is controlled. The PWM 32 controls the amount of power supplied to the motor 1 by changing the ratio of the on-time and off-time of the power transistors 21, 22, 23, 24, 25, 26 of the inverter 20 connected to the three-phase drive winding of the motor 1. is doing. For example, when the rotational speed of the motor 1 is increased, the PWM 32 increases the on-time ratio of the power transistors 21, 22, 23, 24, 25, and 26 by increasing the voltage level of the voltage command Vsp. Control is performed to decrease the ratio, the amount of power supplied to the three-phase drive winding of the motor 1 is increased, and the rotation speed of the motor 1 can be increased.

  Here, when the rotational speed of the motor 1 is increased, the ratio of the on-time of the power transistors 21, 22, 23, 24, 25, 26 is decreased by decreasing the voltage level of the voltage command Vsp contrary to the above. The purpose of the present invention is to increase the amount of electric power supplied to the three-phase drive winding of the motor 1 and increase the rotational speed of the motor 1 by controlling so as to decrease the off-time ratio. It does not deviate.

  Although the motor driving means 30 of the present embodiment has been described as a driving means for supplying a driving voltage to the three-phase driving windings 11, 13, and 15, the motor driving means 30 is connected to the three-phase driving windings 11, 13, and 15. Even if it is a drive means which supplies a drive current, it does not interfere.

  The rotational speed of the motor 1 is detected by the rotational speed detection 4. The rotation speed detection 4 outputs an FG signal having a frequency proportional to the rotation speed of the motor 1 and outputs it to an output terminal 9 connected to the rotation speed detection 4. If the output terminal 9 is connected to a servo calculator 60 provided in the device 6 on which the motor is mounted, a speed error is detected by servo calculation from the FG signal, and a motor drive control command is based on the speed error. A voltage command Vsp can be generated.

  In the conventional motor driving apparatus having servo circuits such as the rotation speed error detection 700 and the error amplifier 800 described with reference to FIGS. 2 and 3, the circuit constant for setting the control method or the stability of the servo is the motor driving apparatus. Fixed internally. For this reason, speed control with good servo characteristics can be obtained at a certain rotation speed, but it is difficult to ensure stable speed control with high accuracy at a wide range of different rotation speeds. It was. However, like the motor drive device of the present invention, the servo calculation function is left to the device 6 on which the motor outside the motor drive device is mounted, and the voltage command Vsp that is a motor drive control command is provided on the device 6 on which the motor is mounted. The following characteristics can be obtained by enabling generation from the servo arithmetic unit 60 or the like that controls the speed control of the motor.

  First, if the servo calculator 60 included in the device 6 on which the motor of FIG. 1 is mounted is replaced with the same one as the rotation speed error detection 700 and the error amplifier 800 of FIG. Equivalent motor speed control is possible. When the motor rotation speed is changed and used at different rotation speeds, the servo calculator 60 included in the device 6 on which the motor is mounted has an appropriate servo calculation so that the speed characteristics are optimized at the rotation speeds. If processing is set, highly accurate and stable speed control can be ensured. That is, stable speed control is possible over a wide range of rotation speeds.

  Further, in the configuration shown in FIG. 2 of the conventional example, the voltage command Vsp, which is a motor drive control command, is generated by the speed reference signal and the FG signal, so that the motor speed control is not controlled regardless of these signals. I can't handle it. However, in the motor driving device of the present invention, since the motor speed control command can be performed by external input, the motor speed control can be handled uncontrolled regardless of the speed reference signal or the FG signal, and the motor with a higher degree of freedom. Control can be performed.

  In addition, by entrusting the motor speed control function to the device 6 on which the external motor is mounted, the circuit scale can be reduced, the number of elements required for speed control can be reduced, and the cost of the motor drive device can be reduced. Can do.

  The motor driving device of the present invention is useful for a motor for driving a printer, a copying machine, a scanner, a fax machine, or a combination of these.

1 is a schematic diagram of a motor drive device according to a first embodiment of the present invention. Schematic diagram of motor drive device in conventional example Schematic of the error amplifier provided in the motor drive device in the conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Printed circuit board 4 Rotation speed detection 6 Equipment in which motor is mounted 10 Voltage command Vsp input terminal 11, 13, 15 Three-phase drive winding 20 Inverter 21, 22, 23, 24, 25, 26 Power transistor 30 Motor drive Means 31 Waveform generation means 32 PWM
60 Servo computing unit of equipment equipped with motor

Claims (2)

Waveform generating means that is built in or integrated with a motor having a mover and a three-phase drive winding, and that generates a waveform signal for driving the motor at a phase timing based on a position detection signal of the mover, and the waveform signal Driving means for supplying a driving voltage or a driving current to the three-phase driving winding, and a motor control terminal to which a control signal is input, the control signal is input from a device on which the motor is mounted, The servo calculation for controlling the motor speed to a desired value is performed by the device, and the control signal is a signal based on the result of the servo calculation performed by the device, and the three-phase by the driving means is generated by the control signal. A motor drive device capable of controlling the magnitude of the drive voltage or drive current of the drive winding. 2. The motor driving apparatus according to claim 1, wherein the device on which the motor is mounted is a printer, a copier, a scanner, a fax machine, or a combination of these.