JP2016052223A - Motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor drive device capable of ensuring safety by judging whether power supply can be applied to an AC motor.SOLUTION: The motor drive device includes a pair of connectors 50 for connecting/disconnecting a motor drive wire 33 and an encoder wire 39 at an intermediate position of the wires, so that a power supply side and a driven side where a motor 10 and an encoder part 20 are provided can be electrified and blocked. A controller 30 includes a detection circuit 37 for detecting the presence/absence of a current in a signal processing portion 23 of the encoder part 20. While the paired connectors 50 are set in a disconnection state and the current in the signal processing portion 23 of the encoder part 20 cannot be detected by the detection circuit 37 in spite of power supply from a commercial power source 31 to the controller 30, the controller sets a mode in which power is not supplied to the motor 10 by blocking the motor drive wire 33 in spite of input of a drive switch 35.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor drive device that ensures safety when starting a motor.

  Patent Document 1 discloses a control technique for detecting the abnormality of the motor rotation and stopping the rotation of the motor.

  In Patent Document 1, a control object is a DC servo motor, and a difference between speed detection data obtained from an encoder for detecting rotation of the motor and target speed data is always detected, and this difference is a constant value. When exceeded, it is determined that the rotation is abnormal and the motor is stopped.

  In Patent Document 1, the abnormal rotation is detected not after the motor start command is instantaneous, but after a certain period of time that should be normally rotated after the motor is started. Although an abnormality can also occur at the moment of motor start command, in Patent Document 1, even if there is an error at the moment of motor start command, it is predicted that the steady rotation will occur immediately after a relatively short time, and this is detected by the encoder. It can be dealt with by detecting it, and since the voltage applied to the motor is DC and low voltage, it is considered that there is no problem with abnormality at the moment of motor start command. However, it is needless to say that it is better to deal with the abnormality immediately when the power is turned on for starting the motor even if the applied voltage is low.

  In addition, if the same idea is simplified, it is possible to detect an abnormality only by judging whether or not the motor is rotating after a certain time after the voltage is applied to the motor. Even in the case of driving an AC motor that cannot perform the above-described method, the method for dealing with the DC servo motor described above can be applied.

JP-A-8-237983

  However, when the technique of Patent Document 1 is applied to an AC motor that applies a commercial power source as described above, an abnormality cannot be found until a certain time has elapsed since the motor start command is issued, although it is a short time. In the meantime, the question of human safety remains. Normally, a motor drive line for applying commercial power to an AC motor is a pair of connectors that separates the motor drive line into a controller side on the power supply side and a motor side for the convenience of installation work of the apparatus using the motor. It is connected. In the unforeseen situation where the connector is disconnected and the contact point is exposed after the installation of the device is completed, the operator's finger can be applied immediately to the voltage applied to the AC motor (drive switch input). Touching an abnormal location causes a short circuit of the commercial power supply, which is very dangerous and becomes a big problem.

  In view of such circumstances, even if the motor is an AC motor that receives power from a commercial power supply, the present invention detects an abnormality at the same time as the power is turned on, or detects an abnormality at the same time as the occurrence of a connector disconnection after the power is turned on. Another object of the present invention is to provide a motor drive device that can determine whether or not to supply power to an AC motor and ensure safety.

  A motor driving apparatus according to the present invention includes a controller that has a drive switch and outputs power from a commercial power source when the drive switch is input, a motor that is driven by receiving power from the controller via a motor drive line, and a motor Encoder unit for detecting rotation, a DC power source for driving the encoder unit, an encoder line for connecting the DC power source to the encoder unit, and an encoder signal line for sending an encoder signal as an output signal from the signal processing unit of the encoder unit to the controller And have.

  In such a motor drive device, in the present invention, the motor drive line and the encoder line are provided with a connector that makes a pair for bringing the motor drive line and the encoder line into contact with each other collectively or individually at an intermediate position of these electric wires. The controller has a detection circuit that detects the presence or absence of current in the signal processing unit of the encoder unit, and the paired connectors are in a separated state. When the current in the signal processing unit of the encoder unit cannot be detected by the detection circuit despite the power supply to the controller of the commercial power supply, the motor drive line is cut off regardless of the input of the drive switch, and the motor It is characterized by being configured to be in a mode in which no power is supplied to.

  According to the present invention having such a configuration, when the paired connectors are disconnected and in a separated state, the motor drive line is cut off and the power supply is stopped, so that even when the drive switch is input. The motor does not rotate. As a matter of course, when not only the motor drive line but also the encoder line is disconnected, neither an encoder signal in the encoder unit indicating rotation nor a current for signal processing in the signal processing unit of the encoder unit is generated. In the present invention, the detection circuit of the controller detects a state where no current is generated. Therefore, the controller determines that the current is not present even though the drive switch is in the power-on state, and therefore shifts to the non-connection mode. In the non-connection mode, even if the contact of the connector is exposed due to the disconnection of the connector before or after the input of the drive switch, the motor drive line is cut off and no power is supplied. Accidents such as short circuits are prevented. Therefore, the present invention can be applied to any type of motor regardless of the type of motor, and safety is ensured.

  In the present invention, as described above, the presence or absence of current in the signal processing unit provided in the encoder unit for detecting the rotation of the motor at the time of power supply to the controller or after power supply is detected in the controller. When the current is “None”, the controller shifts to the non-connection mode and disables the power supply to the motor via the motor drive line. Accidents caused by short circuit of commercial power can be prevented.

1 is a schematic configuration diagram of a motor drive device as one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this embodiment, as an example of the present invention, a motor provided in a drive unit for winding and rewinding a screen and a shutter (not shown; hereinafter simply referred to as “screen”) that can move up and down is driven. An apparatus for this will be described.

  FIG. 1 is a schematic configuration diagram of a motor drive device according to the present embodiment. The motor driving device includes a motor 10 for moving the screen up and down, an encoder unit 20 for detecting rotation of the motor 10, and a controller 30 that outputs electric power from the commercial power source and supplies the electric power to the motor 10. ing. In the present embodiment, the case where the motor 10 is an AC single-phase motor driven by a commercial power supply AC100V will be described. However, the type of the motor is not limited to this and may be a motor driven by any power source. The motor 10 is provided at the end of the screen winding shaft. The motor 10 is driven to rotate, and the screen is lifted by winding the screen with the winding shaft. Descend. In the present embodiment, with respect to the rotation direction of the motor 10, the rotation direction that raises the screen is the forward rotation direction, and the rotation direction that lowers the screen is the reverse rotation direction.

  In the present embodiment, the motor 10 stops rotating when the winding (up) or rewinding (down) of the screen is completed. Regarding the rotation angle position of the motor 10, the position at the time when the winding of the screen is completed is called “forward rotation stop position”, and the position at the time when the screen rewinding is completed is called “reverse rotation stop position”. When there is no need to distinguish between them, it is simply referred to as “rotation stop position”. The rotation stop position of the motor 10 can be set in advance.

  For example, the encoder unit 20 generates an encoder signal based on a wheel 21 attached to the shaft of the motor 10, a sensor 22 positioned opposite to the wheel 21, and a detection signal from the sensor 22. And a signal processing unit 23. The wheel 21 is provided with a plurality of sectors in the periphery for encoding by any one of optical, electromagnetic, inductive, capacitive and the like. The sensor 22 is an element that detects the circumferential movement of the sector, and is connected to the signal processing unit 23. The signal processing unit 23 receives the detection signal from the sensor 22 and performs calculations for calculating specifications regarding the rotation of the motor such as the presence / absence of rotation of the motor, the rotation speed, and the rotation angle position, and generates these as encoder signals. To do.

  A controller 30 that controls the rotational drive of the motor 10 is connected to the motor 10. The controller 30 has a motor drive line 33 that connects a commercial power supply 31 of AC 100 V and the motor 10 via a relay 32, and supplies electric power from the commercial power supply 31 to the motor 10 via the motor drive line 33. It is like that. A DC power supply 34 is connected to the motor drive line 33 at a position before the relay 32 (position on the commercial power supply 31 side). The DC power supply 34 receives AC100V of the commercial power supply 31 and receives a DC of a predetermined voltage. Generate voltage. The DC power source 34 is connected to a relay 32, a drive switch 35, an encoder power source 36, a detection circuit 37, and a CPU 38, and the DC power source 34 supplies DC power for driving to these. The state of the DC power supply is indicated by a broken line in FIG.

  The relay 32 is provided at an intermediate position of the motor drive line 33 and allows or interrupts the supply of power from the commercial power supply 31 to the motor 10 according to the open / close state of the switch. As will be described later, the relay 32 receives the control signal from the CPU 38 to switch the open / close state of the switch.

  In FIG. 1, only one switch is shown in the relay 32, but actually, the relay 32 has a plurality of switches, and the motor 10 rotates forward and backward depending on the combination of the open / closed states of the switches. Is possible. Hereinafter, with regard to the open / close states of the plurality of switches of the relay 32, the open / close state for forward rotation of the motor 10 is referred to as “forward rotation connection state”, and the open / close state for reverse rotation of the motor 10 is referred to as “reverse rotation connection state”. When there is no need to distinguish between the two, it is simply referred to as “connection state”. In addition, a state in which all the switches are “open” to stop the motor 10 and power supply to the motor 10 is interrupted is referred to as a “non-connection state”. Regarding the mode of the controller 30, the mode when the relay 32 is in the connected state is referred to as “connected mode”, and the mode when the relay 32 is in the disconnected state is referred to as “non-connected mode”.

  The drive switch 35 is a switch for inputting a moving direction of the screen in response to a button operation by the operator, and includes an upper operation button 35A for raising the screen and a lower operation button 35B for lowering the screen. Have.

  The encoder power source 36 is connected to the signal processing unit 23 of the encoder unit 20 via the encoder line 39 and supplies DC power to the signal processing unit 23.

  The detection circuit 37 is connected to the signal processing unit 23 of the encoder unit 20, detects the presence / absence of current in the signal processing unit 23, and generates a detection signal corresponding to the presence / absence of the current. In this embodiment, when the detection circuit 37 detects a current in the signal processing unit 23, the detection circuit 37 generates a “current detection signal” indicating that the current is “present” and detects the current in the signal processing unit 23. If not, a “current non-detection signal” is generated indicating that the current is “none”.

  In this embodiment, as seen in FIG. 1, the motor drive line 33 and the encoder line 39 are collectively connected and separated by the connector 50 at an intermediate position between these electric wires. By connecting and disconnecting the connector 50, the power source side on which the controller 30 is provided and the driven side on which the motor 10 and the encoder unit 20 are provided can be energized and disconnected. The connector 50 may have a connector for the motor drive line 33 and a connector for the encoder line 39 separately, and each may be capable of contacting and separating.

  The CPU 38 performs control to switch the open / close state of the relay 32 based on the signals from the drive switch 35 and the detection circuit 37 of the controller 30 and the signal processing unit 23 of the encoder unit 20.

  The CPU 38 sets the relay 32 in the forward rotation connection state when the operator presses the upper operation button 35A of the drive switch 35, and sets the relay 32 in the reverse rotation connection state when the lower operation button 35B is pressed.

  The CPU 38 is connected to the signal processing unit 23 of the encoder unit 20 via the encoder signal line 40, and receives an encoder signal from the signal processing unit 23 via the encoder signal line 40. The CPU 38 always acquires information such as the rotational angle position of the motor 10 by receiving the encoder signal, and maintains the rotational connection state of the relay 32 until the motor 10 reaches the rotation stop position. A control signal is transmitted to the relay 32, and when the motor 10 reaches the rotation stop position, a control signal for bringing the relay 32 into a disconnected state is transmitted to the relay 32.

  Further, when the detection signal from the detection circuit 37 is a “current detection signal” in which the current in the signal processing unit 23 is “present”, the CPU 38 drives the motor 10 with the relay 32 connected. Make it possible. On the other hand, when the detection signal from the detection circuit 37 is a “current non-detection signal” indicating that the current in the signal processing unit 23 is “none”, the CPU 38 has operated the drive switch 35 by the operator. However, the relay 32 is brought into a disconnected state. That is, the controller 30 is shifted to the non-connection mode, and power supply to the motor 10 is disabled.

  Hereinafter, the control operation of the relay 32 by the CPU 38 will be described separately for a normal time when the pair of connectors 50 are connected and an abnormal time when the connectors 50 are not connected separately.

<Operation of CPU 38 under normal conditions>
At normal times when the connector 50 is connected and the motor drive device is operable, if the relay 32 is in the connected state, power from the commercial power supply 31 is supplied to the motor 10 via the motor drive line 33. In addition, power from the encoder power source 36 is supplied to the signal processing unit 23 of the encoder unit 20 through the encoder line 39. Therefore, the detection circuit 37 detects a current in the signal processing unit 23 and generates a current detection signal indicating that the current is “present”. Thus, when the CPU 38 receives the current detection signal from the detection circuit 37, the controller 30 shifts to the connection mode. In the connection mode, when the operation buttons 35A and 35B of the drive switch 35 are operated by the operator, the CPU 38 generates a control signal corresponding to the operation, and sets the connection state of the relay 32 to the “forward rotation connection state”. Alternatively, a “reverse rotation connection state” is set. As a result, electric power from the commercial power supply 31 is supplied to the motor 10 via the relay 32 that is in a connected state according to the operation of the operation buttons 35A and 35B, and the motor 10 is rotationally driven.

<Operation of CPU 38 in case of abnormality>
When the connector 50 is disconnected for some reason and is not connected, the motor drive line 33 and the encoder line 39 are not energized at the position of the connector 50, and the motor drive line 33 and the encoder line 39 are not energized. Each contact portion is exposed. At this time, since the detection circuit 37 does not detect the current in the signal processing unit 23, the detection circuit 37 generates a current non-detection signal indicating that the current is “none”. As described above, when the CPU 38 receives the current non-detection signal from the detection circuit 37, the controller 30 shifts to the non-connection mode, and the CPU 38 always generates a control signal for setting the relay 32 in the non-connection state. That is, in this non-connection mode, the relay 32 is already in the non-connection state before the input operation of the drive switch 35. Therefore, even if the operator erroneously inputs the drive switch 35 under this non-connection mode, the relay 32 is not connected and is maintained in the non-connection state. As a result, since no voltage is generated in the connector 50, even if the operator touches the contact portion exposed at the connector 50, the occurrence of an accident is reliably prevented without causing a short circuit of the commercial power supply. can do.

  Also, after the drive switch is turned on, the controller 30 is connected when the connector 50 is inadvertently disconnected for some reason (when an abnormality occurs) during normal operation (normal) of the motor drive device. From the mode to the non-connection mode, the relay 32 in the connected state is switched to the non-connected state, and as a result, the occurrence of an accident such as a short circuit of the commercial power supply is surely prevented.

DESCRIPTION OF SYMBOLS 10 Motor 20 Encoder part 21 Wheel 22 Sensor 20 Encoder part 23 Signal processing part 30 Controller 31 Commercial power supply 32 Relay 33 Motor drive line 35 Drive switch 37 Detection circuit 39 Encoder line 40 Encoder signal line 50 Connector

Claims (2)

A controller that has a drive switch and outputs power from a commercial power source when the drive switch is input; a motor that is driven by receiving power from the controller via a motor drive line; an encoder unit for detecting rotation of the motor; In a motor drive device having a DC power source for driving the encoder unit, an encoder line for connecting the DC power source to the encoder unit, and an encoder signal line for sending an encoder signal as an output signal from the signal processing unit of the encoder unit to the controller,
It has a pair of connectors that connect and separate the motor drive line and encoder line at the middle position of these wires, and the power source side and the driven side where the motor and encoder section are provided can be energized and disconnected And
The controller has a detection circuit for detecting the presence or absence of a current in the signal processing unit of the encoder unit, and the detection circuit is connected to the pair of connectors in a separated state regardless of the power supply to the controller of the commercial power supply. When the current in the signal processing unit of the encoder unit cannot be detected, the motor drive line is cut off regardless of the input of the drive switch, and the power is not supplied to the motor. A motor drive device.   The motor drive device according to claim 1, wherein the motor drive line and the encoder line are connected by a pair of connectors that are contacted and separated together.

Images