JPS598159B2 - pulse motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse motor drive control system that uses a pulse motor as a drive source and allows smooth rotational driving force to be obtained during continuous rotational driving of the pulse motor.

Generally, a pulse motor is driven and controlled by being supplied with a rectangular waveform pulse signal, and due to its characteristics, it is extremely effective in setting the position of a load body, etc.

However, when it became necessary to have a function that allows a pulse motor to rotate continuously and smoothly in addition to the normal position setting function, conventionally, a damper mechanism, mechanical clutch, etc. were added to the outside of the motor to provide instantaneous drive. It had a buffering function against changes in torque and achieved substantially smooth rotational driving force.

However, in such conventional rotation control means, it is difficult to maintain stable operation due to wear of the above-mentioned mechanism parts, changes in the viscosity of the fluid used in the clutch mechanism, etc., and it is also expensive. Furthermore, since the pulse motor itself, which serves as the drive source, continuously performs step drive using instantaneous starting torque, various inconveniences occur, such as the difficulty of obtaining continuous rotational driving force with a highly accurate constant torque. was.

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1. Smooth rotation control of the I-pulse motor drive signal itself.

This invention provides a drive control system for a pulse motor I that allows smooth rotational drive control.

覐：：：：＝１＝：： １ The principle structure and operation of the present invention will be explained with reference to FIGS. 1 and 2. In FIG. 1, 11 is a motor. , a drive pulse generation unit 12 that generates drive pulses inputs the motor and drive pulses obtained from the drive pulse generation unit 111, and generates a relatively low frequency below a certain frequency during position setting, etc. The input pulse is passed through and output with the same waveform (square wave),
13 is a low-pass filter that transforms an input pulse of a certain frequency or more into a sinusoidal signal waveform and outputs it during smooth continuous rotation drive;
a driver circuit that amplifies the signal that has passed through step 2 to a driving level;
14 is a pulse motor that receives the output of this driver circuit 13 and drives it.

FIG. 2 shows the basic configuration of the low-pass filter 12, where R1, R2, Cl, and C2 are resistors and capacitors with predetermined constants constituting the low-pass filter 12, and AMP is a differential calculation. amplifier, R3, R
4 is a level setting resistor of this operational amplifier AMP.
In such a configuration, the drive pulse generator 11 now generates a signal with a relatively low frequency (for example, for position setting).
When a pulse for driving the motor 1 (with a long period) is output, this pulse is supplied to the low-pass filter 12. However, due to the function of the low-pass filter 12, the input pulse at this time is almost input without being affected by it. The signal is output as it is in the waveform state (square waveform), is supplied to the driver circuit 13, and is amplified into a signal at a driving level.

Therefore, the pulse motor 14 performs normal stepping drive by instantaneous activation in response to an input signal. Further, when the drive pulse generator 11 continuously outputs high-frequency motor drive pulses to continuously drive the pulse motor 14, these pulses are supplied to the low-pass filter 12, and when the CR of the low-pass filter 12 is Due to the charging and discharging action determined by the constant, the high frequency component is cut and the rectangular portion is transformed into a blunted waveform (sine wave shape) and output. Therefore, the pulse motor 14 receives a signal with a drive level approximate to a sine wave and performs smooth rotational driving. When such a pulse motor drive control means is used in a facsimile machine, for example, to set the position of a rotating drum around which a transmitted document or a received recording medium is wound, step drive control using a rectangular wave drive signal is required. When the scanning operation is performed by rotating the drum after the position is set, the scanning operation can be performed with high precision by smooth continuous rotation drive control using a sine wave drive signal. Next, an embodiment of the present invention will be described with reference to FIGS. 3 to 5.

FIG. 3 shows the main structure of the present invention, and the same components as those in FIGS. 1 and 2 are given the same reference numerals and the explanation thereof will be omitted. The configuration shown in FIG. 3 is particularly different from the configuration shown in FIG. A series circuit consisting of a switching transistor Q2 and an auxiliary capacitor C4 is connected in parallel,
A high frequency control signal Vf whose voltage value is linearly varied is supplied from the outside to the gate electrodes of each of the transistors Ql and Q2 to set the resonant frequency of the low-pass filter. By having such a configuration,
Each of the transistors Ql and Q2 is switched according to the value of the control signal f, and the capacitance of the low-pass filter 12 is apparently linearly varied as the number of times the transistors Ql and Q2 are switched, thereby shifting the resonance frequency. . Therefore, when the control signal Vf is fixed, when the input pulse frequency exceeds a certain value, it is transformed into a sine wave, and when the input pulse frequency is fixed, by varying the set value of the control signal Vf, It is possible to perform sinusoidal deformation on any input pulse.
Here, the operation of the configuration shown in FIG. 3 will be explained in detail with reference to FIGS. 4A, b to 5A, a', B, b'. When fixed at a predetermined reference level, the pass filter 12
The characteristics are as shown in Figure a.

At this time, when the drive pulse generator 11 outputs a motor drive pulse that varies from a low frequency to a high frequency as shown in FIG.
As shown in Figure 5a, input pulses with low frequencies are passed through and output with almost the same waveform (square wave), while input pulses with high frequencies are transformed into sinusoidal waveforms and output. be done. The signal that has passed through this low-pass filter 12 is amplified to a drive level signal by a driver circuit 13 and then supplied to a pulse motor 14. Therefore, after a stepping operation at a low frequency, the pulse motor 14 receives a sinusoidal drive signal and shifts to a smooth rotating operation. Furthermore, when the input pulse frequency to the low-pass filter 12 is kept constant and the value of the control signal Vf is changed, the characteristics of the low-pass filter 12 change as shown in FIG. 4b according to the value of the control signal Vf. Therefore, even if the frequency of the motor and drive pulses output from the drive pulse generator 11 is constant, if you want to obtain smooth continuous rotation, you can change the value of the control signal Vf (by increasing the bias voltage). ), a sinusoidal drive pulse signal can be obtained, and thereby the pulse motor 14 can be smoothly controlled in rotation. As detailed above, according to the present invention, a pulse motor is used as a drive source, a low-pass filter is interposed between the drive pulse generator and the pulse motor driver circuit, and the motor 1 is driven by the drive pulse generator. By varying the pulse frequency or the resonance frequency of the low-pass filter, it is possible to control the smooth rotation of the pulse motor at any time, which is inexpensive, easy, and highly accurate without using a mechanical control structure. It is possible to provide a drive control method for a pulse motor that can perform stepping drive and smooth rotational drive control suitable for setting the position of a pulse motor.

[Brief explanation of drawings]

The figure is for explaining one embodiment of this invention.
The figure is a block diagram, Figure 2 is a basic circuit diagram of a low-pass filter, Figure 3 is a circuit diagram of a low-pass filter in one embodiment, and Figures 4A and b are the same diagrams as in Figure 3 above. Characteristic diagram of low-pass filter, Fig. 5 A, a', B, bl
FIG. 2 is a waveform diagram for explaining the operation in one embodiment. 11..., drive pulse generator, 12...
・Low pass filter, 13...driver circuit,
14...Pulse motor.

Claims (1)

[Claims] 1. A pulse motor drive control system comprising a pulse motor, in which drive pulses are supplied to a motor drive circuit via a low-pass filter, characterized in that the pulse motor is equipped with means for varying the resonance frequency of the low-pass filter. Drive control method.