JPH083148Y2 - Motor control device - Google Patents

Description

[Detailed Description of the Invention] <Industrial application field> The present invention relates to a motor control circuit, and in particular, it determines a short circuit abnormality and a motor lock abnormality according to the energization amount, and when the motor lock abnormality occurs, the motor lock state is detected. A technique for enabling recovery from an abnormality.

<Prior Art> In FIG. 2 showing a conventional motor control device, a drive control means A includes a logic circuit 1 for outputting a drive signal for forward rotation of a motor 3 based on a control signal V _IN , and a reverse rotation. And a logic circuit 2 that outputs a drive signal for use with the.

Transistors Tr _{1 to} Tr ₄ are transistors that control the amount of electricity supplied to the motor 3. PNP transistors Tr ₁ and Tr ₃ are emitters connected to the power supply of voltage V _B via the contact of relay RL,
The collectors are connected to the collectors of NPN transistors Tr ₂ and Tr ₄ , respectively, and the bases are connected to the logic circuits 1 and 2 via resistors r ₁ and r ₃ , respectively.
Are connected to the output terminals of the logic circuits 1 and 2, and are turned on, that is, turned on, by inputting a drive signal having a voltage of "0" from the logic circuits 1 and 2, respectively. Transistors Tr ₂ and Tr ₄ have emitters connected to a current detection resistor r ₅ , and have bases connected to the output ends of logic circuits 2 and 1 via resistors r ₂ and r ₄ , respectively. It turns on by inputting a drive signal that is a voltage from 1 to "1". Also, the coil of the motor 3 is connected between the collectors of the transistors Tr ₁ and Tr _{2 and} the collectors of the transistors Tr ₃ and Tr ₄ , and when the transistors Tr ₁ and Tr ₄ are turned on, the motor 3 rotates forward and the transistor Tr ₃ , Reverse rotation occurs when Tr ₂ turns ON.

Abnormality detecting means B, a resistor r ₅ connected between the emitter and ground of the transistor Tr _2, Tr _4, the resistance r ₆ ~r _8, r
₁₃ , and a differential amplifier circuit 14 configured by the operational amplifier 4 and outputting a detection signal by the voltage across the resistor r ₅ ,
Connected sequentially from the power supply of constant voltage V _Z to the ground, resistors r ₉ and r ₁₀ dividing the constant voltage V _Z , and the inverting input terminal connected to the output terminal of the operational amplifier 4, and the resistance r at the non-inverting input terminal. ₉ , a comparator 5 which is connected to the connection point of r ₁₀ to input a reference voltage, and when the output voltage of the operational amplifier 4 becomes equal to or higher than the reference voltage, determines that there is an abnormality and outputs a voltage of “0”.

The flip-flop circuit 6 has a RES terminal and a comparator 5
Connected to the output terminal of the comparator 5, and outputs the voltages of "1" and "0" by the output voltages of "1" and "0" of the comparator 5, respectively. The transistor Tr ₅ has its base connected to the output terminal of the flip-flop circuit 6 via the resistor r ₁₂ , its emitter connected to ground, and its collector connected to the voltage V _B via the coil of the relay RL.
When the voltage of "1" is input from the flip-flop circuit 6 when it is connected to the power source of the relay RL, it is turned on, and a current is passed through the coil of the relay RL connected to the power source and the collector of the transistor Tr ₅ to make the contact of the relay RL. close.

 Next, the operation will be described.

When the power of the device is turned on, the voltage "1" is output from the flip-flop circuit 6, the transistor Tr ₅ is turned on,
The contact of the relay RL is closed and the motor 3 can be energized.

If the motor 3 and the transistor Tr ₁ to Tr ₄ are normal,
The output voltage of the operational amplifier 4 due to the current blood detected by the resistor r ₅ is lower than the reference voltage of the comparator 5, the comparator 5 outputs the voltage “1” to the flip-flop circuit 6, and the flip-flop circuit 6 outputs “1”. continues to output the voltage to the transistor Tr _5, the transistor Tr ₅ will remain oN, and the contacts of the relay RL are closed. When the motor 3 is rotated in the forward direction, the voltage of "0" or "1" is supplied as the drive signal from the logic circuit 1 by the control signal V _IN to the transistor Tr.
₁ , output to Tr _4, and "0" and "1" respectively when rotating in reverse.
Is output to the transistors Tr ₃ and Tr ₂ , and the motor 3 is driven.

In the unlikely event that an abnormality occurs, for example, a motor lock abnormality occurs in which the rotation shaft of the motor 3 is loaded and rotation is blocked, or due to damage of the transistor Tr ₁ or transistor Tr ₂ , or the drive signal Transistor Tr ₁ and transistor Tr ₂ are turned on at the same time due to malfunction.
When such a short circuit abnormality occurs, the current flowing through the coil of the motor 3 increases, the voltage drop of the resistor r ₅ increases, and the output voltage of the operational amplifier 4 becomes higher than the reference voltage of the comparator 5. Since in these cases the comparator 5 outputs the voltage of "0" to the flip-flop circuit 6, the flip-flop circuit 6 outputs a voltage of "0" to the base of the transistor Tr _5, the transistor Tr ₅ is OFF,
No current flows through the coil of relay RL, and the contact of relay RL opens. When the relay RL is opened, the energizing circuit of the motor 3 is disconnected from the power source of the voltage V _B , and the motor 3 and the transistors Tr _{1 to} Tr _{4 are connected.}
Is protected.

<Problems to be solved by the invention> By the way, in the case of short circuit abnormality, transistor damage,
Or the power supply of the voltage V _B will have an adverse effect such as the burnout of the harness used for wiring, so it is necessary to completely shut off the power supply of the voltage V _B , but if the motor lock is abnormal, the motor control device is normal. So, in terms of performance, voltage
It is preferable to allow automatic recovery without turning off V _B. However, in the conventional motor control device, relay RL
Has been turned off, and the device must be turned off and then turned on again to recover.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a motor control device capable of automatically returning when a motor lock abnormality occurs.

<Means for Solving the Problems> Therefore, in the present invention, drive control means for outputting a drive signal for controlling the current to the motor based on the control signal, a power switch for disconnecting the energizing circuit of the motor from the power source, Provided are transistor switch means for controlling the energization amount to the motor based on the drive signal of the drive control means, and abnormality detection means for monitoring the abnormality of the energization circuit by the energization amount of the energization circuit of the motor and detecting the abnormality, In the motor control device configured to stop the energization of the motor when an abnormality is detected, the abnormality detection means sets two predetermined thresholds to the energization amount of the energization circuit of the motor, while the energization amount equal to or more than the short-circuit current threshold value. To detect a short circuit abnormality in the energizing circuit and to detect the amount of current that is less than the threshold for short circuit current and greater than the threshold for motor lock current. And a motor lock abnormality detecting means for detecting a motor lock abnormality, and when the short circuit abnormality detecting means detects an abnormality, a power switch control means for disconnecting the power switch based on the abnormality detection signal. And a shutoff means for stopping the output of the drive signal of the drive control means for a predetermined time based on the abnormality detection signal when the motor lock abnormality detection means detects an abnormality.

<Operation> According to the above configuration, in a normal state, the drive signal of the drive control means causes power to be supplied from the power supply to the motor via the power switch and the transistor switch means, and the motor is driven.

When the energization amount of the energizing circuit is equal to or more than the threshold value for short-circuit current, the short-circuit abnormality detection unit detects a short-circuit abnormality, and the power switch control unit controls the power switch based on the abnormality detection signal of the short-circuit abnormality detection unit. Disconnect the motor energization circuit from the power supply.

When the energization amount of the energizing circuit is equal to or more than the threshold value for the motor lock current and less than the threshold value for the short circuit current, the motor lock abnormality detecting unit detects the motor lock abnormality, and the disconnecting unit remains connected to the power supply circuit of the motor. Stops the output of the drive signal from the drive control means to the transistor switch means for a predetermined time based on the output of the abnormality detection signal of the motor lock abnormality detection means, and the current to the motor is cut off. After a lapse of a predetermined time, a drive signal is output again from the drive control means, and when the cause of the motor lock abnormality is removed when the motor is energized, the normal state can be automatically restored.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings.
The same elements as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 1 showing the present embodiment, in the abnormality detecting means B, resistors r _{9 to} r ₁₁ are sequentially connected from the power source of constant voltage V _Z to the ground, the connection point of resistors r ₉ and r ₁₀ , the resistor r ₁₀ , At the connection point of r ₁₁ , the non-inverting input terminals of the comparator 5 which is the short circuit abnormality detecting means and the comparator 7 which is the motor lock abnormality detecting means are connected to each other, and the comparators 5 and 7 respectively input the reference voltage. There is. Therefore, the reference voltage of the comparator 7 is lower than the reference voltage of the comparator 5. The reference voltages of the comparators 5 and 7 correspond to the short current threshold and the motor lock current threshold, respectively.
The comparator 7 has an inverting input terminal connected to the output terminal of the operational amplifier 4 and outputs a voltage of "0" when the output voltage of the operational amplifier 4 becomes equal to or higher than the reference voltage of the comparator 7.

The output cutoff circuit 8 which is cutoff means is connected to the output end of the comparator 7 at the input end and connected to the terminals of the logic circuits 1 and 2 which are the drive control means at the output end from the output voltage “1” of the comparator 7. When the trailing edge of "0" is input as the abnormality detection signal, the output of the drive signals of the logic circuits 1 and 2 is stopped.

 Next, the operation will be described.

When the power of the device is turned on, the voltage "1" is output from the flip-flop circuit 6, the transistor Tr ₅ is turned on,
The contact of the relay RL is closed and the motor 3 can be energized.
If there is no abnormality, a current of 3 to 4 A normally flows through the energizing circuit of the motor 3 to drive the motor 3.

If a short circuit occurs and a short current of, for example, several tens of amperes flows in the energizing circuit of the motor 3, the voltage drop of the resistor r ₅ increases, so that the output voltage of the operational amplifier 4 is higher than the reference voltage of the comparator 5 as in the conventional case. to become, the comparator 5 outputs the voltage of an abnormality detection signal "0", the flip-flop circuit 6 is a power switch control means provides a voltage of "0", the transistor Tr ₅ is OFF, the power switch The contact of a certain relay RL is opened and the current does not flow in the energizing circuit of the motor 3, so that the energizing circuit of the motor 3 is protected.

When a motor lock abnormality occurs and a current of, for example, 6 to 7 A flows in the energizing circuit of the motor 3, the output voltage of the operational amplifier 4 is lower than the reference voltage of the comparator 5 and higher than the reference voltage of the comparator 7. Therefore, since the comparator 5 outputs the voltage of "1", the relay RL remains closed, and the output voltage of the comparator 7 changes from "1" to "0".
And the abnormality detection signal is output. The output cutoff circuit 8 receives the abnormality detection signal from the logic circuit 1,
The output of the drive signal of 2 is stopped for a predetermined time, and the transistor
All of Tr _{1 to} Tr ₄ are turned off and the motor 3 is de-energized. After a lapse of a predetermined time, the drive signal is output again from the logic circuit 1 or 2, and when the cause of the motor lock abnormality is removed when the motor 3 is energized, the normal state is automatically restored.

With this configuration, when a current of several tens of amperes flows in the energizing circuit due to the failure of the motor control device, the output voltage of the operational amplifier 4 becomes equal to or higher than the reference voltage of the comparator 5, and the short circuit abnormality is detected. At this time, the relay RL is opened as in the conventional case, the energizing circuit of the motor 3 is disconnected from the power source of the voltage V _B , and the energizing circuit of the motor 3 is protected.
When a current of 6 to 7 A flows in the energizing circuit, the operational amplifier 4
Output voltage becomes equal to or higher than the reference voltage of the comparator 7 and lower than the reference voltage of the comparator 5, a motor lock abnormality is detected, and the relay RL is closed and the motor 3 is de-energized. After a lapse of a predetermined time, when the transistors Tr ₁ and Tr ₄ or the transistors Tr ₃ and Tr ₂ are controlled again by the drive signal from the logic circuit 1 or 2 and the motor 3 is energized, the cause of the motor lock abnormality is If removed, it can automatically return to the normal state. Therefore, when an abnormality occurs, you can determine what kind of abnormality is in the open / closed state of the relay RL, and if the motor lock is abnormal, the relay RL is not turned off. You can return.

<Effect of Device> As described above, according to the present invention, when the energization amount equal to or more than the threshold value for the short-circuit current is detected, the power supply switch disconnects the motor supply circuit from the power supply to protect the motor supply circuit. However, above the threshold for motor lock current,
When an energization amount less than the short current threshold is detected,
The cutoff means stops the output of the drive signal of the drive control means to the transistor switch means for a predetermined time, and the motor is de-energized. Then, after a lapse of a predetermined time, a drive signal is output again from the drive control means, and when the cause is removed when the motor is energized, the normal state can be automatically restored. Therefore, when an abnormality occurs, it is possible to distinguish between a short-circuit abnormality and a motor lock abnormality, and in the case of a motor lock abnormality, the cause can be removed to automatically restore the normal state, improving the performance of the motor control device. To do.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment according to the present invention, and FIG. 2 is a conventional circuit diagram. A ... Drive control means, B ... Abnormality detection means, 1, 2 ...
Logic circuit, 3 …… Motor, Tr _{1 to} Tr ₄ …… Transistor,
5, 7 ... Comparator, 6 ... Flip-flop circuit, 8 ... Output cutoff circuit

Claims (1)

[Scope of utility model registration request] 1. A drive control means for outputting a drive signal for controlling a current to the motor based on the control signal, a power switch for disconnecting a power supply circuit of the motor from a power source, and a motor based on the drive signal for the drive control means. Transistor switching means for controlling the energization amount to the motor, and abnormality detection means for monitoring the abnormality of the energizing circuit by the energization amount of the energizing circuit of the motor to detect the abnormality, and energizing the motor is stopped when the abnormality is detected. In the motor control device configured as described above, the abnormality detection unit sets two predetermined thresholds to the energization amount of the energization circuit of the motor, and detects an energization amount equal to or more than the threshold value for short-circuit current to detect a short circuit abnormality of the energization circuit. Short-circuit abnormality detection means for detecting, and a motor lock abnormality detection unit for detecting an energization amount that is less than the short-circuit current threshold value and greater than or equal to the motor lock current threshold value. Data lock abnormality detecting means, and when the short-circuit abnormality detecting means detects an abnormality, the power switch control means disconnects the power switch, and when the motor lock abnormality detecting means detects an abnormality, the abnormality A motor control device comprising: a cutoff unit that stops the output of the drive signal of the drive control unit based on a detection signal for a predetermined time.