JPS6315699A - Pulse motor control system - Google Patents

Abstract

PURPOSE:To reduce vibration, heat and noise generated in a pulse motor substantially by shortening a conducting time of driving pulse at a low-speed rotation. CONSTITUTION:When a control circuit 1 judges that a space control speed is slower than a prescribed one, said circuit accesses a timer controller 11 within a control signal generator 10 together with a timer controller 3 within a driving pulse generator 2. A timer signal outputted from the driving pulse generator 2 becomes a rotational pulse with excitation phases A-D via a counter 6 and a logic 7 and is sent to a driving pulse controller 20. On the other hand, the timer controller 11 receives an output signal of the counter 6, accesses a timer value data table 12 on the basis of said output signal, reads out timer data stored in said table, controls the gate-ON time of gates 21-24 corresponding to the excitation phases A-D via a logic circuit 13 and shortens a conducting time of driving pulse.

Description

[Detailed Description of the Invention] [Summary] In the pulse motor control method, when the voltage applied to the pulse motor is constant and the pulse motor is driven by the rotational torque at constant speed rotation, the rotation speed of the pulse motor is low. (low speed rotation), excessive torque is generated compared to the required rotation torque, which increases the vibration generated in the pulse motor and increases noise. In order to solve this problem, the rotation speed of the pulse motor is increased. When the rotation speed is lower than a predetermined number (low speed rotation), by configuring the pulse motor to shorten the energization time of the drive pulse applied to the pulse motor at that time, it is possible to significantly reduce the vibration and noise applied to the pulse motor. Become.

[Industrial application field]

The present invention relates to a pulse motor control method for a printer.

For example, when controlling the space in an impact printer'ATL using a pulse motor, there are two drive methods for the pulse motor: a constant voltage method and a constant current method. Generally, the constant voltage method is cheaper in structure and easier to control. For,
It is widely used in low-cost printer devices.

In addition, the torque curve of the pulse motor is shown in Figure 7 (B
), when the voltage is constant, the lower the rotation speed, the higher the torque, and the higher the rotation speed (the lower the torque becomes).

On the other hand, in the design, in order to ensure that the torque is the required torque when the rotational speed is high, that is, when the rotation is stable at high speed, when the rotational speed is low (i.e., when rotating at low speed), surplus torque is generated. Become.

It is desired that such a case be dealt with in a simple manner and that efficient space control can be achieved.

[Prior Art] FIG. 5 is a block diagram for explaining a conventional example, FIG. 6 is a diagram for explaining the state of drive pulses, and FIG. 7 is a diagram for explaining the drive torque of a pulse motor.

The block diagram shown in FIG. 5 shows a part of the drive circuit for the pulse motor 9 in the printer device, and its configuration is as follows: a control circuit 1 that controls various processing operations performed internally; A drive pulse generator 2 that generates a plurality of pulses having a predetermined cycle based on a stored timer table; and a counter 6 that switches the excitation phase of the pulse motor 9 to the plurality of pulses output from the drive pulse generator 2. Logic 7 that calculates and determines phase data corresponding to the excitation phase in which pulse motor 9 exists (in this example, phase data for excitation phases A-D, such as drive order) from the counter value of counter 6; The printer 7 includes a driver 8 that applies a drive current to a pulse motor 9 based on the phase data output from the pulse motor 7, and a pulse smoke 9 that serves as a drive source for space control during data printing.

The drive pulse generator 2 is connected to a timer controller 3 that accesses a timer direct data table 4 that stores data that determines the sending time and period of the signal generated from the timer 5, and the timer value data table 4 and the timer 5.
It is equipped with.

In this example, the phase data for the excitation phases A-D of the pulse motor 9 output from the logic 7 described above are shown in FIG. 6(A).
As shown on the upper side, two phases are driven at the same time.
The signal is sent to the driver 8 using a so-called two-phase excitation method.

The driver 8 applies a drive current to the pulse motor 9 based on the phase data for each excitation phase A to D, but the current waveform at this time is the lowest row in FIG. The waveform will be as shown in (showing the waveform).

It should be noted that the phase data for each excitation phase A to D have the same period and on-time (that is, the energization time of the drive current), and are only out of phase. Further, the rotational torque of the pulse motor 9 obtained from the phase data for each of the excitation phases A to D is set at the rotational torque required for constant speed rotation.

FIG. 7(A) shows the rotational speed curve of the pulse motor 9, and FIG. 7(B) shows the relationship between the number of rotations of the pulse motor 9 and the torque.

Normally, as shown in FIG. 7(A), the rotation of the pulse motor 9 changes depending on the acceleration rotation state at the start of rotation, whether it is at high speed (curve with sign (al)) or at low speed (curve with sign (b)). There is a constant speed rotation state.

Furthermore, when the pulse motor 9 rotates at a high speed, as shown by the symbol +al in FIG. 6(B), the energization time and period of the applied current are short (and therefore, the average of the applied current is also small).

On the other hand, at low speeds, as shown by symbol (b) in FIG. 6(B), the application time and cycle of the applied current become longer, and therefore the applied current becomes larger on average.

The timer value data table 4 stores output patterns of pulses of each phase A to D for the pulse motor 9 to reach a predetermined rotation state (ie, constant speed rotation state) within a predetermined time.

Also, the timer value data table 4 is the timer controller 3.
The specified output cover turn is sent out by access from
Control is performed so that the rotational speed curve is as indicated by symbol (al) or symbol (b) shown in the figure (A>).

[Problem that the invention seeks to solve]

As mentioned above, looking at the relationship between the rotational speed and rotational torque of the pulse motor 9 whose rotation is controlled, as shown in FIG. 7(B), when the applied voltage is constant, the lower the rotational speed, the more That is, the lower the rotation speed (or accelerated rotation state), the higher the rotation torque, and the higher the speed rotation (or constant speed rotation state), the lower the rotation torque.

On the other hand, the design rotational torque is generally set as the rotational torque at high speed rotation (or constant speed rotation state) as the required torque.

Therefore, during low speed rotation (or accelerated rotation state), there is a surplus of rotational torque, which causes problems such as increased vibration of the pulse motor 9, increased heat generation, and increased noise during space control. There was a point.

[Means for solving problems]

FIG. 1 shows a block diagram illustrating the invention in detail.

The principle block diagram shown in FIG. 1 is based on the control circuit 1 described in FIG. Drive pulse generator 2. counter 6, logic 7
, driver 8. A drive pulse control means (
A control signal generation means (control signal generation unit) 10 that accesses the drive pulse control unit (drive pulse control unit) 20 and, if the space speed during character data printing is slower than a predetermined speed, the energization time of the drive pulse sent from the logic 7 at that time is controlled. Drive pulse control means (
(drive pulse control section) 20.

[Effect]

When the pulse voltage applied to the pulse smoke 9 is constant and the rotational torque at constant speed rotation is used as the required torque,
When the rotation speed of the pulse motor 9 is lower than a predetermined rotation speed (low speed rotation), a drive pulse control means (drive pulse control unit) 20 controls to shorten the energization time of the drive pulse sent from the logic 7 at that time. By shaping the energization time of the drive pulse sent out from the logic 7 to a predetermined time and shortening the energization time applied to the pulse motor, it is possible to significantly reduce the vibration 2 heat generation and noise generated in the pulse motor. becomes.

〔Example〕

The gist of the present invention will be specifically explained below with reference to embodiments shown in FIGS. 2 to 4.

FIG. 2 is a block diagram explaining the present invention in detail, FIG. 3 is a diagram explaining the control situation in the embodiment of the present invention, and FIG. 4 is a diagram explaining the torque curve in the embodiment of the present invention. . Note that the same reference numerals indicate the same objects throughout the figures.

The control signal generating unit IO of this embodiment controls the gate-on time of the timer controller 11 that accesses the timer value data table 12 and the drive pulse control unit 20. a timer value data table 12 that stores data regarding the sending time of control signals for the 11 operations; and a logic that sends a control signal that controls the gate-on time of the drive pulse controller 20 based on the data sent from the timer value data table 12. The circuit 13 (programmable monostable) is configured.

Further, the drive pulse control section 20 is configured to include gates 21 to 24 corresponding to each phase A to D.

If the control circuit 1 determines that the space control speed is slower than the predetermined speed, it accesses the timer controller 11 in the control signal generator 10 together with the timer controller 3 in the drive pulse generator 2.

The timer signal output from the drive pulse generator 2 is sent to the excitation phase A shown in FIG. 3(A) via the counter 6 and logic 7.
-D rotation pulse is sent to the drive pulse control section 20.

On the other hand, the timer controller 11 takes in the output signal of the counter 6, accesses the timer value data table 12 based on this, reads out the timer data stored therein, and outputs the excitation phase A-D via the logic circuit 13. A signal is sent out to control the gate on time of the gates 21 to 24 corresponding to the gates.

The drive pulse control unit 20 converts the rotation pulses of the excitation phases A to D shown in FIG. Each of the gates 21 to 2 is activated for the energization time determined by the control signal from the logic circuit 13 sent out in synchronization with the rising edge of
4 is opened and the pulse motor 9 is driven via the driver 8.

In the case of the control signal shown in FIG. 3(C), for example, the rising edge of the rotation pulse of the excitation phase A-D is used as a timing signal to stop energizing the preceding phase, and the falling edge is used as a timing signal to start energizing the next phase, which is used to control the pulse motor 9. It is also possible to control the energization time.

Furthermore, when such control is performed, when it is performed in the acceleration state region (slewing region) of the rotational speed curve of the pulse motor 9 shown in FIG. 7(A), when it is performed in the constant speed state, or when it is performed in both states. etc. are possible.

Figure 4 (A) shows the acceleration state area (slewing area)
Figure 4 (B) shows the case where the control is performed in a constant speed state, and normally it is possible to sufficiently achieve the purpose with control in the constant speed state shown in Figure 4 (B). .

The curve shown in the figure is the speed curve (C) shown by the dotted line.
is formed into the speed curve (d) shown by the solid line.

As mentioned above, when the rotational speed of the pulse motor 9 is lower than the predetermined speed, the current energization time for the pulse motor 9 at that time is shortened (by doing so, vibration noise caused by wasted torque is reduced, and the average current value is suppressed). By being
Power saving becomes possible.

〔Effect of the invention〕

According to the present invention as described above, it is possible to significantly reduce vibration 1 heat generation and noise generated in the pulse motor, and there is an effect that power consumption can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram explaining the present invention in detail, FIG. 2 is a block diagram explaining the present invention in detail, FIG. 3 is a diagram explaining the control situation in an embodiment of the present invention, and FIG. 4 is a block diagram explaining the present invention in detail. FIG. 5 is a block diagram explaining the conventional example; FIG. 6 is a diagram explaining the state of drive pulses; FIG. 7 is a diagram explaining the drive torque of the pulse motor. are shown respectively. In the figure, 1 is a control circuit, 2 is a drive pulse generator, and 3.1
1 is the timer controller, 4.12 is the timer value data table, 5 is the timer, 6 is the counter, 7 is the logic, 8 is the driver, 9 is the pulse motor, 1
0 is a control signal generation section, 13 is a logic circuit, 20 is a drive pulse control section, and 21 to 24 are gates. <A) <8) Trees] Figure 5 showing the shift curve in late September for the 11 h゛1 slot L)

Claims (1)

[Scope of Claims] In a printer device that drives a pulse motor (9) with drive pulses of multiple phases, the energization time of the drive voltage applied to the pulse motor (9) is the same as that of the multiple phases to the pulse motor (9). control signal generating means (10) for generating a control signal that is shorter than the energization time from the logic (7) that outputs the drive pulse; pulse control means (20) for controlling the energization time of the drive pulse to be shortened based on the control signal outputted from the control signal generation means (10), and when the rotational speed of the pulse motor is faster than a predetermined speed; ,
The logic (7) to the drive pulse control means (20)
The output from the control signal generation means (10) determines the energization time of the drive pulse input from the drive pulse control means (10).
20) A pulse motor control system characterized in that the pulse motor (9) is driven by shaping during the time when the pulse motor (9) is turned on.