JP6474220B2 - Motor drive device - Google Patents

Description

  The present invention relates to a motor drive device.

  2. Description of the Related Art Conventionally, a motor drive device having a safe torque-off (STO) function that cuts off a drive current supplied to a motor in response to a cut-off signal from the outside is known in order to ensure safety when using the motor. A conventional motor driving device having an STO function is described in, for example, Japanese Patent Application Laid-Open No. 2010-284051.

In the inverter device for motor drive described in JP 2010-284051 A, when a cutoff signal is input from the outside, a switching element (IGBT) of a switching circuit (IGBT bridge circuit) of the inverter device via two cutoff circuits By turning off, the drive signal supplied to the motor is cut off.
JP 2010-284051 A

  In a motor drive device having an STO function, when a shut-off signal is input from the outside and the shut-off signal is released after the drive current to the motor is shut off, the motor is driven again. At this time, if the drive command is continuously input before the drive current is cut off, the behavior of the motor may not be stabilized during the re-drive.

  For example, if the drive command is a high-speed rotation command, the motor is driven suddenly at a high rotational speed from a stopped state, so that a large current flows in the motor or the switching element that supplies the drive current to the motor becomes hot. There is a risk of becoming. If the behavior of the motor is prevented from becoming unstable during re-driving, the safety when using the motor can be further improved.

  An object of the present invention is to provide a technique for improving safety in a motor drive device having an STO function.

An exemplary first invention of the present application is a motor drive device that supplies a drive current to a motor, and includes an inverter unit having a plurality of switching elements that supply a drive current to each phase of the motor, and is input from the outside Based on a drive command, a calculation unit that outputs a drive signal to the switching element, a drive signal blocking unit provided on a signal line of the drive signal between the calculation unit and the inverter unit, and the motor An abnormality detection unit that outputs a detection signal to at least one of the calculation unit and the drive signal blocking unit based on a driving state, and the abnormality detection unit determines that the motor is in an abnormal state the to the arithmetic unit and the drive signal blocking portion, said outputs an abnormality signal as a detection signal, the drive signal blocking portion, the less the emergency stop signal and the abnormal signal When one is input, the signal line of the drive signal is interrupted between the calculation unit and the inverter unit, and the calculation unit is configured to input at least one of the emergency stop signal and the abnormal signal. This is a motor drive device that stops the output of the drive signal.

  According to the exemplary first invention of the present application, safety can be improved in the motor drive device having the STO function.

FIG. 1 is a block diagram showing the configuration of the motor drive device according to the first embodiment. FIG. 2 is a flowchart showing a flow of safe operation in the calculation unit of the motor drive device according to the first embodiment. FIG. 3 is a block diagram illustrating a configuration of a motor driving device according to a modification. FIG. 4 is a block diagram illustrating a configuration of a motor drive device according to a modification. FIG. 5 is a block diagram illustrating a configuration of a motor drive device according to a modification.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
<1-1. Configuration of Motor Drive Device>
First, the configuration of the motor drive device 1 will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a motor drive device 1 according to the first embodiment. The motor driving device 1 is a device for controlling the driving of the motor 9 by supplying a driving current to the motor 9.

  In the present embodiment, the motor 9 to be driven by the motor drive device 1 is a three-phase brushless DC motor. The motor 9 has a stator winding of each phase of U phase, V phase, and W phase. When the drive current S41 is supplied to the stator windings of each phase, torque is generated between the stator and the rotor, and the rotor is rotationally driven. However, the motor to be driven by the motor drive device according to the present invention may be a single-phase motor or a motor with a brush.

  Moreover, the motor 9 of this embodiment is a motor for driving industrial machines, such as a belt conveyor and a chain block. The motor drive device 1 has a safe torque-off (STO) function that cuts off a drive current supplied to the motor 9 in response to an input of an emergency stop command in order to prevent an accident during driving of the industrial machine.

  As shown in FIG. 1, the motor drive device 1 includes an emergency stop command unit 20, a calculation unit 30, an inverter unit 40, and a drive signal blocking unit 50. An emergency stop command S12 is input to the emergency stop command unit 20 from the outside. When the emergency stop command S12 is input, the emergency stop command unit 20 outputs an emergency stop signal S20 to a later-described stop signal input unit 32 of the calculation unit 30 and the drive signal blocking unit 50.

  The calculation unit 30 outputs a drive signal S31 to the inverter unit 40 in accordance with a drive command S11 input from the outside. The calculation unit 30 includes a drive signal generation unit 31, a stop signal input unit 32, and a detection signal input unit 33. In this embodiment, each part of the calculating part 30 is comprised by the microcontroller.

  The drive signal generation unit 31 generates a drive signal S31 that is a PWM signal in accordance with a drive command S11 input from the outside, and outputs the drive signal S31 to the switching circuit 41 described later of the inverter unit 40. The drive signal S31 is three pairs of voltage signals for the three pairs of switching elements included in the switching circuit 41.

  An emergency stop signal S20 is input from the emergency stop command unit 20 to the stop signal input unit 32. When the emergency stop signal S20 is input, the stop signal input unit 32 outputs the first stop signal S32 to the drive signal generation unit 31. Further, when the emergency stop signal S20 is not input, the stop signal input unit 32 stops the output of the first stop signal S32.

  When the first stop signal S32 is input from the stop signal input unit 32 to the drive signal generation unit 31, the drive signal generation unit 31 outputs the drive signal S31 even when the drive command S11 is input. Stop. Thus, the first STO function for cutting off the supply of the drive current S41 to the motor 9 when the emergency stop command S12 is input by the emergency stop command unit 20, the stop signal input unit 32, and the drive signal generation unit 31. Is realized.

  The detection signal S43 is input to the detection signal input unit 33 from an abnormality detection unit 43 described later. When the detection signal S43 input from the abnormality detection unit 43 is a normal signal S431 described later, the detection signal input unit 33 stops outputting the second stop signal S33. On the other hand, when the detection signal S43 input from the abnormality detection unit 43 is an abnormality signal S432 described later, the detection signal input unit 33 outputs the second stop signal S33 to the drive signal generation unit 31. When the second stop signal S33 is input from the detection signal input unit 33 to the drive signal generation unit 31, the drive signal generation unit 31 outputs the drive signal S31 even if the drive command S11 is input. Stop output.

  The inverter unit 40 supplies a drive current S41 to the motor 9 based on the drive signal S31 input from the drive signal generation unit 31. The inverter unit 40 includes a switching circuit 41, a temperature sensor 42, and an abnormality detection unit 43.

  The switching circuit 41 includes a plurality of switching elements that supply a drive current to each phase of the motor 9. The switching circuit 41 of this embodiment has six switching elements. The six switching elements receive one pair (total of three pairs) of drive signals S31 for each of the U phase, V phase, and W phase of the motor 9. The switching circuit 41 switches the drive timing of each switching element and generates a drive current S41. Thereby, rotation of the motor 9 is controlled.

  In the present embodiment, since the motor 9 is a three-phase motor, the number of switching elements included in the switching circuit 41 is six. The motor driving device of the present invention may supply a driving current to a motor having other specifications such as a single phase motor. In this case, the number of switching elements included in the switching circuit 41 varies depending on the type of motor.

  The temperature sensor 42 is a sensor that detects the temperature of the switching circuit 41. The temperature sensor 42 of this embodiment is provided in the same package as the six switching elements of the switching circuit 41. The temperature sensor 42 outputs the detected temperature S 42 of the switching circuit 41 to the abnormality detection unit 43.

  The abnormality detection unit 43 outputs a detection signal S43 to the detection signal input unit 33 of the calculation unit 30 based on the driving state of the motor 9. When the abnormality detection unit 43 determines that the motor 9 is in the normal driving state, the abnormality detection unit 43 outputs the normal signal S431 as the detection signal S43. Further, when the abnormality detection unit 43 determines that the motor 9 is in an abnormal state, the abnormality detection unit 43 outputs an abnormality signal S432 as the detection signal S43.

  As described above, when the abnormality signal S432 is input from the abnormality detection unit 43 to the detection signal input unit 33, the detection signal input unit 33 outputs the second stop signal S33 to the drive signal generation unit 31. When the second stop signal S33 is input from the detection signal input unit 33 to the drive signal generation unit 31, the drive signal generation unit 31 outputs the drive signal S31 even if the drive command S11 is input. Stop output. As described above, the abnormality detection unit 43, the detection signal input unit 33, and the drive signal generation unit 31 realize a protection function that cuts off the supply of the drive current S41 to the motor 9 when the motor 9 is in an abnormal state. .

  When the emergency stop command S12 is canceled after the drive current to the motor 9 is interrupted by the STO function, the motor 9 is driven again. The motor drive device 1 has the above-described protection function, and cuts off the supply of the drive current S41 to the motor 9 when the motor 9 falls into an abnormal state such as sudden acceleration during re-drive. Thereby, the safety | security at the time of the redrive of the motor 9 improves.

  The abnormality detection unit 43 of the present embodiment determines whether the motor 9 is in an abnormal state or a normal drive state based on the temperature S42 detected by the temperature sensor 42. When the temperature S42 is lower than a preset threshold value, the abnormality detection unit 43 determines that the motor 9 is in a normal drive state. At this time, the abnormality detection unit 43 outputs a normal signal S431 having a predetermined voltage value that is not zero. Further, when the temperature S42 is higher than a preset threshold, the abnormality detection unit 43 determines that the motor 9 is in an abnormal state. At this time, the abnormality detection unit 43 outputs an abnormality signal S432 having a predetermined voltage value that is not 0 different from the normal signal S431.

  Thus, when the motor is in the normal driving state, the abnormality detection unit 43 does not stop the output of the detection signal S43 but outputs the normal signal S431. The detection signal input unit 33 outputs the second stop signal S33 to the drive signal generation unit 31 when the detection signal S43 is not input. When the detection signal S43 is not input, the inverter unit 40 including the abnormality detection unit 43 has stopped driving, or the signal line of the detection signal S43 is between the abnormality detection unit 43 or the abnormality detection unit 43 and the detection signal input unit 33. It is assumed that a failure has occurred.

  In such a case, the detection signal input unit 33 outputs the second stop signal S33, so that the drive signal generation unit 31 can be prevented from outputting the drive signal S31 to the inverter unit 40 that is not driven. In addition, the drive signal generation unit 31 outputs the drive signal S31 to the inverter unit 40 while the abnormality detection unit 43 cannot detect the abnormal state, thereby further suppressing the motor from continuing to drive in the abnormal state. it can.

  The detection signal S43 including the normal signal S431 and the abnormal signal S432 may be a current signal instead of a voltage signal. In this case, the normal signal S431 is a signal having a predetermined current value that is not 0, and the abnormal signal S432 is a signal having a predetermined current value that is not 0 different from the normal signal S431.

  The drive signal cut-off unit 50 is a signal cut-off circuit provided on the signal line of the drive signal S31 between the drive signal generation unit 31 of the calculation unit 30 and the switching circuit 41 of the inverter unit 40. When the emergency stop signal S20 is input from the emergency stop command unit 20, the drive signal cutoff unit 50 blocks the signal line of the drive signal S31 between the drive signal generation unit 31 and the switching circuit 41.

  The drive signal blocking unit 50 blocks the signal line of the drive signal S31 in hardware. Therefore, when the emergency stop signal S20 output from the emergency stop command unit 20 is input simultaneously to the stop signal input unit 32 and the drive signal blocking unit 50, the drive signal generation unit 31 outputs the drive signal S31 in software. The drive signal cut-off unit 50 can cut off the signal line of the drive signal S31 faster than the stop. Thereby, compared with the case where the emergency stop signal S20 is input only to the arithmetic unit 30, the supply of the drive current S41 can be stopped more quickly.

  As described above, the emergency stop command unit 20 and the drive signal cut-off unit 50 realize the second STO function that cuts off the supply of the drive current S41 to the motor 9 when the emergency stop command S12 is input.

  In the present embodiment, the detection signal S43 output from the abnormality detection unit 43 is input to the priority port of the microcontroller constituting the calculation unit 30. Thereby, the operation of the calculation unit 30 by the input of the detection signal S43 is prioritized in terms of hardware over all other operations performed by the calculation unit 30. In other words, when the abnormal signal S432 is input as the detection signal S43, the arithmetic unit 30 stops outputting the drive signal S31 in preference to all other operations performed by the arithmetic unit 30. Therefore, when the motor 9 falls into an abnormal state, the motor 9 can be quickly stopped.

<1-2. Operation of the calculation unit>
Next, the operation of the calculation unit 30 will be described with reference to FIG. FIG. 2 is a flowchart showing an operation flow of the calculation unit 30 of the motor drive device 1 when the motor 9 is used.

  As shown in FIG. 2, when the motor drive device 1 is activated, the calculation unit 30 first determines whether or not the drive command S11 is input to the drive signal generation unit 31 (step ST101). If the drive command S11 is off, the process returns to step ST101 again and enters a standby state. Further, when the drive command S11 is turned on, the drive signal generation unit 31 starts calculating and outputting the drive signal S31 (step ST102).

  While outputting the drive signal S31, the calculation unit 30 determines whether or not the emergency stop signal S20 is input to the stop signal input unit 32 (step ST103). When the emergency stop signal S20 is not input to the stop signal input unit 32 in step ST103, the arithmetic unit 30 next determines whether or not the abnormal signal S432 is input to the detection signal input unit 33 (step ST104). ). When the abnormality signal S432 is not input to the detection signal input unit 33 in step ST104, the arithmetic unit 30 subsequently determines whether or not the drive command S11 is input to the drive signal generation unit 31, that is, the drive command S11 is It is determined whether or not it is on (step ST105).

  If the calculation unit 30 determines that the drive command S11 is continuously on in step ST105, the process returns to step ST103. By repeating Step ST103 to Step ST105, the supply of the drive current S41 such as the input of the emergency stop signal S20, the input of the abnormal signal S432, and the end of the drive command should be stopped throughout the output of the drive signal S31. Keep monitoring to see if things happen.

  In step ST105, when the drive command S11 is turned off and the input of the drive command S11 to the drive signal generator 31 is stopped, the drive signal generator 31 stops outputting the drive signal S31 (step ST106). Then, the process returns to step ST101.

  When the emergency stop command S12 is input to the motor drive device 1 while the drive signal S31 is being output, the emergency stop command unit 20 outputs the emergency stop signal S20 to the stop signal input unit 32. Thereby, in step ST103, the calculating part 30 judges that the emergency stop signal S20 was input. In that case, the stop signal input unit 32 outputs the first stop signal S32 to the drive signal generation unit 31, whereby the drive signal generation unit 31 stops outputting the drive signal S31 (step ST107).

  As a result, the drive signal S31 is not input to the switching circuit 41, and the supply of the drive current S41 to the motor 9 is stopped. That is, when the first STO function is activated, the supply of the drive current S41 to the motor 9 is stopped.

  In the present embodiment, the emergency stop command unit 20 outputs the emergency stop signal S20 to the stop signal input unit 32 and simultaneously outputs the emergency stop signal S20 to the drive signal cutoff unit 50. As a result, the second STO function is activated, and the supply of the drive current S41 to the motor 9 is stopped. As described above, the motor drive device 1 of the present embodiment has two STO functions, thereby improving the safety when the motor 9 is used.

  Thereafter, the arithmetic unit 30 determines whether or not the emergency stop signal S20 has been canceled (step ST108). If the emergency stop signal S20 is still input in step ST108, step ST108 is repeated. That is, the arithmetic unit 30 is in a standby state until the emergency stop signal S20 is canceled. And if emergency stop signal S12 is cancelled | released, the calculating part 30 will judge whether drive instruction | command S11 is input (step ST109).

  When the emergency stop signal S12 is canceled, if the drive command S11 is off, the process returns from step ST109 to step ST101. When the emergency stop signal S12 is canceled and the drive command S11 is on, the drive signal generator 31 resumes outputting the drive signal S31 (step ST110). Then, the process returns to step ST103.

  When an abnormality occurs in the motor 9 while the drive signal S31 is being output (in this embodiment, the temperature detected by the temperature sensor 42 is higher than the threshold value), the abnormality detection unit 43 calculates The abnormality signal S432 is output to the unit 30. Thereby, in step ST104, the calculating part 30 judges that abnormal signal S432 was input. At this time, when the detection signal input unit 33 outputs the second stop signal S33 to the drive signal generation unit 31, the drive signal generation unit 31 stops outputting the drive signal S31 and outputs an alarm (step ST111). . When the arithmetic unit 30 outputs an alarm, for example, the operator can recognize the abnormal state of the motor 9 such as an alarm sound or an alarm lamp being lit.

  Thus, in this motor drive device 1, when abnormality occurs in the motor 9, the protection function works. That is, after the driving of the motor 9 is stopped by the STO function, it is possible to suppress the behavior of the motor 9 from becoming unstable during the re-driving by the protection function. Thereby, the safety | security at the time of use of the motor 9 can be improved more.

  When the output of the drive signal S31 is stopped in step ST111, the arithmetic unit 30 determines whether or not the drive command S11 is turned off (step ST112). If the drive command S11 is still input in step ST112, step ST112 is repeated. That is, the arithmetic unit 30 is in a standby state until the drive command S11 is turned off. When the drive command S11 is turned off, the arithmetic unit 30 stops outputting the alarm and resets the alarm (step ST113). Then, the process returns to step ST101.

  When the abnormal signal S432 is input to the calculation unit 30 in steps ST111 to ST113, the calculation unit 30 outputs the drive signal S31 only when the drive command S11 is input again after the drive command S11 is once turned off. Can output. When the abnormal signal S432 is input to the arithmetic unit 30, even if the drive signal S31 is output again in accordance with the drive command S11 input at that time, the motor 9 is likely to be in an abnormal state again. Therefore, after the abnormal signal S432 is input, the drive command S11 is temporarily turned off and input again, thereby preventing the motor 9 from being in an abnormal state after an emergency stop.

  That is, after the driving of the motor 9 is stopped by the STO function, it is possible to further suppress the behavior of the motor 9 from becoming unstable during the re-driving. Thereby, the safety | security at the time of use of the motor 9 can further be improved.

<2. Modification>
As mentioned above, although exemplary embodiment of this invention was described, this invention is not limited to said embodiment.

  FIG. 3 is a block diagram showing a configuration of a motor drive device 1A according to a modification. The motor drive device 1A includes an emergency stop command unit 20A, a calculation unit 30A, an inverter unit 40A, a drive signal blocking unit 50A, and a switch unit 60A.

  In the example of FIG. 3, the switching circuit 41A has a shunt resistor (not shown). A shunt voltage S411A that is a voltage value of a voltage drop in the shunt resistor is input to the abnormality detection unit 43A. Thereby, when the motor current S9A flows from the motor 9A to the shunt resistor, the abnormality detection unit 43A can detect the value of the current flowing through the motor 9A. The abnormality detection unit 43A determines that the motor 9A is in an abnormal state when the shunt voltage S411A exceeds a preset threshold value.

  Note that the inverter unit 40A may have a current sensor instead of the shunt resistor. In this case, the current sensor detects the current value of the motor current S9A and inputs the current value as a signal to the abnormality detection unit 43A. Then, the abnormality detection unit 43A determines that the motor 9A is in an abnormal state when the current value of the motor current S9A detected by the current sensor exceeds a preset threshold value.

  When the abnormality detection unit 43A determines that the motor 9A is in the normal drive state, the abnormality detection unit 43A outputs a normal signal S431A as the detection signal S43A. If the abnormality detection unit 43A determines that the motor 9A is in an abnormal state, the abnormality detection unit 43A outputs an abnormality signal S432A as the detection signal S43A. The normal signal S431A is a voltage signal having a predetermined voltage value that is not 0, and the abnormal signal S432A is a voltage signal having a predetermined voltage value that is greater than the normal signal S431A.

  The switch unit 60A includes an NPN transistor 61A. An emergency stop signal S20A is input from the emergency stop command unit 20A to the base of the transistor 61A. The collector of the transistor 61A is connected to the signal line of the detection signal S43A between the abnormality detection unit 43A and the detection signal input unit 33A of the calculation unit 30A. The emitter of the transistor 61A is grounded.

  When the emergency stop signal S20A is input from the emergency stop command unit 20A to the switch unit 60A, a current flows from the collector to the emitter of the transistor 61A. Thereby, the voltage value of detection signal S43A input into detection signal input part 33A falls. When the emergency stop signal S20A is input to the switch unit 60A in the normal drive state of the motor 9A, the detection signal S43 input to the detection signal input unit 33A is a predetermined voltage lower than the normal signal S431A from the normal signal S431A. It changes to a stop signal S433A having a value.

  When the detection signal input unit 33A determines that the detection signal S43A is the stop signal S433A, the detection signal input unit 33A outputs the second stop signal S33A to the drive signal generation unit 31A. Accordingly, the drive signal generation unit 31A stops the output of the drive signal S31A even when the drive command S11A is input.

  Thus, in the example of FIG. 3, when the emergency stop command S12A is input by the emergency stop command unit 20, the detection signal input unit 33, the abnormality detection unit 43, and the switch unit 60A, the drive current S41A to the motor 9A is changed. A third STO function for cutting off the supply is realized. By having three STO functions, the safety when using the motor 9A can be further improved.

  In the example of FIG. 3, the detection signal S43A is a voltage signal, but the detection signal S43A may be a current signal. In this case, when the emergency stop command S12A is input, the switch unit 60A changes the current value of the detection signal S43A.

  FIG. 4 is a block diagram showing a configuration of a motor drive device 1B according to another modification. The motor drive device 1B includes an emergency stop command unit 20B, a calculation unit 30B, an inverter unit 40B, and a drive signal blocking unit 50B.

  When the abnormality detection unit 43B determines that the motor 9B is in the normal drive state, the abnormality detection unit 43B stops outputting the detection signal S43B. If the abnormality detection unit 43B determines that the motor 9B is in an abnormal state, the abnormality detection unit 43B outputs an abnormality signal S432B as the detection signal S43B to the detection signal input unit 33B and the drive signal blocking unit 50B of the calculation unit 30B. Thus, when the motor 9B is in the normal drive state, the abnormality detection unit 43B stops outputting the detection signal S43B instead of outputting a normal signal having a current value or voltage value other than 0 as the detection signal S43B. May be.

  When the abnormal signal S432B is input to the drive signal cut-off unit 50B, the drive signal cut-off unit 50B is connected to the signal line of the drive signal S31B between the drive signal generation unit 31B of the calculation unit 30B and the switching circuit 41B of the inverter unit 40B. Shut off. Thereby, compared with the case where the abnormal signal S432B is input only to the arithmetic unit 30B, the supply of the drive current S41B to the motor 9B can be more reliably stopped when the motor 9B falls into an abnormal state. That is, the safety when using the motor 9B can be further improved.

  FIG. 5 is a block diagram showing a configuration of a motor drive device 1C according to another modification. The motor drive device 1C includes an emergency stop command unit 20C, a calculation unit 30C, an inverter unit 40C, and a drive signal cutoff unit 50C.

  In the example of FIG. 5, the inverter unit 40C includes a switching circuit 41C, a temperature sensor 42C, an abnormality detection unit 43C, and an inverter cutoff unit 44C. The inverter cutoff unit 44C is provided inside the inverter unit 40C and on the signal line of the drive signal S31C between the drive signal generation unit 31C of the calculation unit 30C and the switching circuit 41C.

  If the abnormality detection unit 43C determines that the motor 9C is in an abnormal state based on the temperature S42C input from the temperature sensor 42C, the detection signal input unit 33C of the calculation unit 30C and the inverter cutoff unit 44C are detected as a detection signal S43. An abnormal signal S432C is output. When the abnormality signal S432C is input from the abnormality detection unit 43C, the inverter cutoff unit 44C blocks the signal line of the drive signal S31C between the drive signal generation unit 31C and the switching circuit 41C. Thereby, when the detection signal S43C is input only to the arithmetic unit 30C, the supply of the drive current S41C to the motor 9C can be stopped more reliably when the motor 9C falls into an abnormal state. That is, the safety when using the motor 9C can be further improved.

  In the above-described embodiment, the emergency stop signal is input to both the calculation unit and the drive signal cutoff unit, so that the two STO functions of the first STO function and the second STO function are realized. However, the present invention is not limited to this. The emergency stop signal may be input to only one of the calculation unit and the drive signal blocking unit. Even in this case, one of the first STO function and the second STO function is realized.

  In the above-described embodiment and modification, the abnormality detection unit outputs a detection signal to at least the calculation unit, but the present invention is not limited to this. The abnormality detection unit may output the detection signal only to the drive signal blocking unit. That is, the abnormality detection unit may output a detection signal to at least one of the calculation unit and the drive signal blocking unit. Thereby, when the motor falls into an abnormal state, the supply of drive current to the motor can be stopped.

  Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

  The present invention can be used for a motor drive device.

1, 1A, 1B, 1C Motor drive unit 9, 9A, 9B, 9C Motor 20, 20A, 20B, 20C Emergency stop command unit 30, 30A, 30B, 30C Calculation unit 31, 31A, 31B, 31C Drive signal generation unit 32 Stop signal input unit 33, 33A, 33B, 33C Detection signal input unit 40, 40A, 40B, 40C Inverter unit 41, 41B, 41C Switching circuit 42, 42C Temperature sensor 43, 43A, 43B, 43C Abnormality detection unit 44C Inverter cutoff unit 50, 50A, 50B, 50C Drive signal cutoff unit 60A Switch unit 61A Transistor S9A Motor current S11, S11A Drive command S12, S12A Emergency stop command S20, S20A Emergency stop signal S31, S31A, S31B, S31C Drive signal S32 First stop signal S33, 33A second stop signal S41, S41A, S41B, S41C drive current S411A shunt voltage S42, S42C Temperature S43, S43A, S43B detection signal S431, S431A normal signal S432, S432A, S432B, S432C abnormal signal S433A stop signal

Claims (10)

A motor driving device for supplying a driving current to a motor,
An inverter unit having a plurality of switching elements for supplying a driving current to each phase of the motor;
Based on a drive command input from the outside, an arithmetic unit that outputs a drive signal to the switching element;
Between the arithmetic unit and the inverter unit, a drive signal blocking unit provided on a signal line of the drive signal,
Based on the driving state of the motor, an abnormality detection unit that outputs a detection signal to at least one of the calculation unit and the drive signal blocking unit;
Have
When the abnormality detection unit determines that the motor is in an abnormal state, the abnormality detection unit outputs an abnormality signal as the detection signal to the calculation unit and the drive signal blocking unit
When at least one of the emergency stop signal and the abnormal signal is input, the drive signal cut-off unit cuts off the signal line of the drive signal between the calculation unit and the inverter unit,
The operation unit stops the output of the drive signal when at least one of the emergency stop signal and the abnormal signal is input.
The motor driving device according to claim 1,
When the abnormal signal is input, the calculation unit stops the output of the drive signal in preference to all other operations performed by the calculation unit. The motor driving device according to claim 1 or 2,
The motor drive device in which the said inverter part has the said abnormality detection part. The motor drive device according to any one of claims 1 to 3,
The abnormality detection unit detects a current value flowing through the motor or a heat generation temperature of the switching element, and outputs the abnormality signal when the detected current value or the heat generation temperature exceeds a preset threshold value. Output motor drive device. The motor drive device according to any one of claims 1 to 4,
When the abnormality detection unit determines that the motor is in a normal driving state, the abnormality detection unit outputs a normal signal as the detection signal,
The normal signal is a signal having a predetermined voltage value that is not 0 or a predetermined current value that is not 0,
The motor drive device, wherein the abnormal signal is a signal having a predetermined non-zero voltage value different from the normal signal or a predetermined non-zero current value different from the normal signal. The motor driving device according to claim 5,
A switch unit connected to a signal line of the detection signal between the abnormality detection unit and the calculation unit;
The switch unit is a motor drive device that changes a current value or a voltage value of the detection signal when the emergency stop signal is input. The motor driving device according to claim 6,
The switch unit is an NPN transistor,
The emergency stop signal is input to the base of the NPN transistor,
A collector of the NPN transistor is connected to a signal line of the detection signal between the abnormality detection unit and the calculation unit,
The emitter of the NPN transistor is grounded,
When the emergency stop signal is input from the emergency stop signal to the NPN transistor, the detection signal becomes a stop signal having a voltage value lower than that of the normal signal.
When the arithmetic unit determines that the detection signal is the stop signal, the operation unit stops outputting the drive signal.
A motor driving device according to any one of claims 1 to 7,
When the abnormal signal is input to the calculation unit, the calculation unit outputs the drive signal only when the drive command is re-input after the drive command is once turned off. . The motor driving device according to any one of claims 1 to 8,
When the abnormality detection unit determines that the motor is in an abnormal state, the inverter unit stops supplying the drive current to the motor. The motor drive device according to claim 9,
The inverter unit is
The motor drive device further comprising an inverter shut-off unit that shuts off the drive signal input from the calculation unit to the switching element when the abnormality detection unit determines that the motor is in an abnormal state.

Images