JP2565847Y2 - Brushless motor control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a control device for a brushless motor.

(Prior Art) Conventionally, a brushless motor is known in which a rotation speed is controlled in accordance with a duty ratio of a speed control pulse signal and the rotation direction can be controlled in accordance with a polarity signal indicating the rotation direction.

(Problems to be Solved by the Invention) Therefore, this type of motor control circuit requires an instruction member for instructing the rotation direction of the motor and a speed setting member for setting the rotation speed of the motor. But,
Providing such two types of members separately tends to complicate the operation.

An object of the present invention is to enable each setting of the rotation speed and the rotation direction to be performed by a single adjustment member. An object of the present invention is to provide a brushless motor control device with improved operability.

(Means for Solving the Problems) A feature of the present invention for solving the above problems is that a brushless motor is driven in either the forward or reverse direction according to a direction instruction signal at a rotational speed according to a duty ratio of a speed control pulse transmitter. Motor control device for controlling a motor drive circuit for controlling the speed of the motor in a normal direction and a second region for adjusting the speed in a reverse direction within a predetermined adjustment range. A setter for generating an output signal having a level corresponding to a position, a first signal generator for performing the level discrimination in response to the output signal and outputting the direction indication signal, and a first signal generator in response to the output signal; A second control signal outputting a control signal in which the level corresponding to the absolute value of the speed set in the first area and the level corresponding to the absolute value of the speed set in the second area correspond to each other. A signal generator; and a third signal generator which outputs a pulse signal having a duty ratio corresponding to the level of the control signal as the speed control pulse signal in response to the control signal.

(Operation) A control command to the motor drive circuit is issued by operating the setting device. When the control in the normal rotation direction is performed, the first region is used, and a desired rotation speed is set in the first region. On the other hand, when controlling in the reverse direction, the second
The area is used, and a desired rotation speed is set in the second area.

In which region the rotation speed is set is determined by the level discriminating operation of the output signal in the first signal generator, and a direction indicating signal is output based on the result of the determination.

The second signal generator outputs a control signal based on the output signal. The control signal is a signal having characteristics corresponding to the level given to the absolute value of each speed set in the first area and the level given to the absolute value of each speed set in the second area. . Based on this control signal, the third signal generator outputs a speed control pulse signal having a duty ratio corresponding to the rotation speed set in one of the required areas.

The motor drive circuit responds to the direction instruction signal and the speed control pulse signal output by the setting operation of the setting device, and drives the brushless motor in accordance with the conditions set by the setting device.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a motor drive circuit 2 for driving a brushless motor 1 and a control device 20 for controlling the motor drive circuit 2 according to the present invention. The brushless motor 1 is a three-phase motor including armature coils 1a, 1b, and 1c. The motor drive circuit 2 includes a three-phase logic controller 3 integrated into an integrated circuit.
And the brushless motor 1, as shown in FIG.
Transistors 4-9, resistors 10-12, and AND gate
They are connected via known circuits 13 to 15. 3
As the phase logic controller 3, for example, a commercially available dedicated integrated circuit (TA8412P-3, manufactured by Toshiba) can be used. The motor drive circuit 2 configured as described above is known, receives power supply from the DC power supply 16, and controls the rotation direction of the brushless motor 1 in response to a direction instruction signal Sd output from the control device 20, In response to the speed control pulse signal Ss, the rotation speed is controlled according to the duty ratio of the signal Ss.

FIG. 2 shows a detailed circuit diagram of the control device 20 of FIG. The control device 20 has a variable resistor 21, one fixed terminal 21a of the variable resistor 21 is grounded, and the other fixed terminal 21b is connected to the output line 17 of the DC power supply 16. That is, a DC voltage E of a predetermined constant level is applied between the fixed terminals 21a to 21b of the variable resistor 21, and an output voltage signal V corresponding to the adjustment state of the variable resistor 21 is output from the movable terminal 21c. This is the configuration that is output.

In the illustrated embodiment, the variable resistor 21 constitutes a slide type linear operation type setting device 70 as shown in FIG. 3, and its adjustment knob 21d is moved from the position "-H" to the position. It is provided as a setting device for setting the rotation direction and rotation speed of the brushless motor 1 that can be adjusted in the range of “+ H”.

The range in which the position P of the adjustment knob 21d is + L ≦ P ≦ H is an adjustment range for rotating the brushless motor 1 in a predetermined positive direction, and the forward rotation speed is set according to the position. In the illustrated example, the position of + L is the set position of the minimum rotation speed, and the set rotation speed increases as the position is closer to + H, and is set to the maximum rotation speed when P = + H.

On the other hand, the range where the position P of the adjustment knob 21d is −H ≦ P ≦ −L is an adjustment range for rotating the brushless motor 1 in a predetermined negative direction, and the rotational speed of the reverse rotation depends on the position. Is set. In the illustrated example, the position of -L is the set position of the minimum rotation speed, and the set rotation speed increases as the position approaches -H, and is set to the maximum rotation speed when P = -H. In the range of -L <P <+ L, the rotation of the brushless motor 1 is stopped.

FIG. 4 shows how the level of the output voltage signal V changes when the position P of the adjustment knob 21d is changed from -H to + H. As shown in FIG. 4, the level of the output voltage signal V changes linearly with the change of the position P,
When P = + H, the level is E and the position P is -H
If it is at the position C which is just halfway between + H and + H, the level is
The configuration is 1 / 2E.

Returning to FIG. 2, the output voltage signal V is applied to the first signal generator 30.
Has been entered. In the first signal generator 30, 31 is a voltage comparator and 32 to 35 are resistors, which constitute a known level discriminating circuit. The voltage dividing circuit constituted by the resistors 32 and 33 divides the DC voltage E supplied from the DC power supply 16 and supplies a 1/2 E level reference voltage to the negative input terminal of the voltage comparator 31. . On the other hand, the output voltage signal V is applied to its + input terminal. Therefore, when the level of the output voltage signal V is larger than 1 / 2E (C <P ≦ + H), the output level of the voltage comparator 31 is Becomes high level, and when the level of the output voltage signal V is 1 / 2E or less (−H <P ≦ C), the output level of the voltage comparator 31 becomes low level. The output of the voltage comparator 31 is output as a direction instruction signal Sd,
It is input to the phase logic controller 3 (see FIG. 1).

The second signal generator 40 outputs the control signal M having the same level when the speed is set by the variable resistor 21 as a setting device and the absolute value of the set speed is the same. Circuit configuration. Second signal generator 40
In the figure, 41 is an operational amplifier, 42 to 47 are resistors, 48 and 49 are diodes, and the operational amplifier 41 is configured to function as an inverting amplifier. The voltage dividing circuit constituted by the resistors 43 and 44 supplies the voltage of the level of E / 2 to the + input terminal of the operational amplifier 41, and the output voltage signal V is supplied to the-input terminal thereof through the resistor 42. Has been entered. Therefore, when the level of the output voltage signal V is equal to or less than E / 2, that is, −H ≦ P
If ≤C, the output level of the operational amplifier 41 decreases as the level of the output voltage signal V increases. The output voltage signal V is applied to the anode of the diode 49 via the resistor 47, so that the level of the output voltage signal V becomes E /
Until the value reaches 2 (until P = C), the diode 49 is in a reverse bias state.

When the level of the output voltage signal V exceeds E / 2, that is, when the position P is in the range of C <P ≦ + H, the level of the output of the operational amplifier 41 becomes smaller than E / 2.
Are in a reverse bias state, and the diode 49 is in a forward bias state, so that the output voltage signal V is output via the diode 49.

As a result, when the position P changes from -H to + H, the level of the control signal M output from the second signal generator 40 changes as shown in FIG.

The control signal M is input to a third signal generator 50 including a triangular wave generation circuit 51, and is applied to a + input terminal of a voltage comparator 52 to which a triangular wave signal TS from the triangular wave generation circuit 51 is applied to a-input terminal. Have been.

The triangular wave signal TS is a signal that changes between the level of E / 2 and the level of E as shown in FIG.
Therefore, when the level of the control signal M reaches the level m shown in FIG. 6A, the pulse signal shown in FIG. 6B is output from the voltage comparator 52 as the speed control pulse signal Ss. You. As can be seen from FIGS. 6A and 6B, the speed control pulse signal Ss depends on the level of the control signal M.
Will change. In the illustrated embodiment, the duty ratio increases as the level m increases. This speed control pulse signal Ss
Is applied to one input terminal of the AND gate 23 via the resistor 22.

Reference numeral 60 indicates that the inhibition signal IS for closing the AND gate 23 and preventing the speed control pulse signal Ss from being supplied to the motor drive circuit 2 in the range of -L <P <+ L. This is a prohibition circuit for outputting and comprises a voltage comparator 61 and resistors 62 to 67. Voltage comparator 61
The voltage signal VQ of the level Q shown in FIG. 5 is applied to a negative input terminal of a voltage dividing circuit composed of resistors 62 and 63, and an output voltage signal V is applied to a positive input terminal thereof. Has been applied. Therefore, the output of the voltage comparison circuit 61 is -L
Only when <P <+ L, is the low level state. As a result, the AND gate 23 is closed when -L <P <+ L, and the speed control pulse signal Ss is not supplied to the motor drive circuit 2. That is, in this case, the AND gates 13 to 15 are closed, and the rotation of the brushless motor 1 is stopped.

Next, the operation of the control device 20 will be described. Knob 21
If the set position P of d is in the range of + L ≦ P ≦ + H, the first
The level of the direction instruction signal Sd output from the signal generator 30 becomes high, and the three-phase logic controller 3 executes control for rotating the brushless motor 1 in the forward direction in response to this. At this time, the second signal generator 40 outputs a control signal M having a level corresponding to the set rotation speed according to the position P, and outputs a speed control pulse signal Ss having a duty ratio corresponding to the set rotation speed. . The AND gates 13 to 15 of the motor drive circuit 2 are opened and closed in response to the speed control pulse signal Ss, whereby the rotation speed of the brushless motor 1 is determined according to the position of the knob 21d.

On the other hand, in the setting state of -H≤P≤-L, the level of the direction instruction signal Sd is low, and the three-phase logic controller 3 rotates the brushless motor 1 in the reverse direction in response to this. The control to make it perform is performed. The second signal generator 40 outputs a control signal M having a level according to the set position P at this time, and outputs a speed control pulse signal Ss having a duty ratio corresponding to the set rotational speed. Since the power supplied to the brushless motor 1 is controlled according to the duty ratio, the rotation speed of the brushless motor 1 is determined according to the position of the knob 21d.

When the adjustment position P of the knob 21d is in the range of -L <P <+ L, the AND gate 23 is closed by the inhibition signal IS,
The rotation of the brushless motor 1 stops.

As can be seen from the above description, by providing at least a normal rotation direction adjustment region and a reverse rotation adjustment region for a single variable resistor 21, the rotation direction and rotation of the brushless motor 1 can be controlled by a single adjustment member. Each speed can be set, and a control device with extremely excellent operability can be configured.

(Effects of the Invention) According to the present invention, as described above, the setting of the rotation direction and the setting and adjustment of the rotation speed of the brushless motor are extremely performed by a single setting member composed of a variable resistor and other appropriate members. It has advantages such as easy operation and simplification of the configuration of the operation panel.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a control system for drive control of a brushless motor using a control device according to the present invention, and FIG. 2 is a circuit diagram of the control device according to the present invention shown in FIG. FIG. 3 is a circuit diagram showing one embodiment, FIG. 3 is a front view of a setting device including the variable resistor shown in FIG. 2, and FIG. 4 shows a level characteristic of an output voltage signal output from the variable resistor. FIG. 5 is a characteristic diagram showing a level characteristic of a control signal output from the second signal generator of FIG. 2, and FIGS. 6 (a) and 6 (b) are shown in FIG. It is a waveform diagram of the signal of each part. 1 ... brushless motor, 2 ... motor drive circuit, 20 ...
... Control device, 21 ... Variable resistor, 30 ... First signal generator, 40 ... Second signal generator, 50 ... Third signal generator, 70
... Setting device, Sd... Direction instruction signal, Ss... Speed control pulse signal, V... Output voltage signal, M... Control signal.

Claims (1)

(57) [Scope of request for utility model registration] 1. A brushless motor control device for controlling a motor drive circuit for driving a brushless motor in one of forward and reverse directions in accordance with a direction instruction signal at a rotational speed in accordance with a duty ratio of a speed control pulse signal. A setter for generating an output signal of a level corresponding to a desired adjustment position within a predetermined adjustment range including a first area for adjusting the speed in the direction and a second area for adjusting the speed in the reverse direction; and A first signal generator responsive to the output signal to perform the level discrimination and output the direction indication signal;
A second signal generator for outputting a control signal in response to the output signal, wherein a level corresponding to the absolute value of the speed set in the first area and a level corresponding to the absolute value of the speed set in the second area correspond to each other; And a third signal generator for outputting a pulse signal having a duty ratio according to a level of the control signal as the speed control pulse signal in response to the control signal. .