JP2005069160A - Motor-driven fan control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continue the operation of a fan by forcibly applying a current to a fan driving motor without a motor driving part even if operational abnormality occurs in the motor driving part of the fan driving motor. <P>SOLUTION: On detecting the over temperature, overcurrent, overvoltage and switching operational abnormality of the respective semiconductor switching elements (e.g. FET 25, 26) constituting the output stage, an abnormality detecting part 29 in a motor driving part 20 adapted to drive the respective motors 2, 3 for driving a radiator cooling fan and a capacitor cooling fan in PWM control system supplies abnormal information through a data communication part 22 to a main control part 10. A forced current application control part 14 in the main control part 10 drives the respective relay contacts 412, 413 of a forced current application part 40 in the closed state on receiving the abnormal information to apply battery power supply 4 to the respective motors 2, 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electric fan control device that drives a cooling fan, a blower fan, and the like.

  In a vehicle with an air conditioner, a cooling medium flowing in a condenser and a radiator is cooled by operating two cooling fans. The motor for driving the cooling fan is driven by pulse width modulation control, so that the rotation speed of the motor is continuously varied (see Patent Document 1).

By monitoring the current flowing in the semiconductor switching element that drives the motor and limiting the pulse width in the pulse width modulation control to a constant value, the motor current is limited, or the driving of the semiconductor switching element is stopped. Protection against electric current is achieved (see Patent Document 2).
JP-A-10-2222 Japanese Patent Laid-Open No. 10-8959

  When the driving of the semiconductor switching element is stopped to protect the semiconductor switching element, the operation of the cooling fan is stopped. For this reason, cooling may be insufficient.

  The present invention has been made to solve such problems, and an object of the present invention is to provide an electric fan control device that can continue the operation of a fan even when an abnormality occurs in the operation of a circuit unit that drives a motor. .

  In order to solve the above problems, an electric fan control device according to the present invention controls a motor that drives a fan and a switching operation of one or more semiconductor switching elements based on an operation command supplied from a main control unit. The motor drive unit that controls the power supplied to the motor and supplies abnormality information to the main control unit when an abnormality is detected in the operation state of the semiconductor switching element by the abnormality detection unit, and the motor is forced based on the forced operation command A forced energization unit that energizes and a main control unit that supplies an operation command to the motor drive unit and controls the forced energization unit to a forced energization state or a forced energization state for a certain time when abnormality information is supplied from the motor drive unit With.

  The abnormality detection unit outputs abnormality information when any of overcurrent, overvoltage, and overtemperature of the semiconductor switching element is detected.

  The electric fan control device according to the present invention forcibly energizes the motor by the forcible energization unit when an abnormality is detected in the operation of the motor drive unit that controls the power supplied to the motor based on the operation command. Therefore, even if an abnormality occurs in the operation of the motor drive unit, the operation of the fan can be continued by forcibly driving the motor by the forced energization unit.

  Hereinafter, the best mode for carrying out the invention will be described based on examples.

  FIG. 1 is a block diagram showing an embodiment of an electric fan control device according to the present invention, and shows an electric fan control device of an automotive cooling system. The electric fan control device 1 controls a DC motor (hereinafter referred to as a motor) 2 that drives a radiator cooling fan (not shown) and a DC motor (hereinafter referred to as a motor) 3 that drives a condenser cooling fan (not shown). . The electric fan control device 1 includes a main control unit 10 including an engine electronic control unit (engine ECU), a motor drive unit 20 that drives the motors 2 and 3, and a battery power supply to the motors 2 and 3 and the motor drive unit 20. 4, a power supply relay 31 for supplying power to the motors 2, 3 without using the motor drive unit 20, a battery power supply 4, an ignition switch 5, and fuses 6, 7. Etc.

  When the ignition switch 5 is turned on, the battery power supply 4 is supplied to the main control unit 10 via the fuse 6, and the battery power supply 4 is energized to the excitation winding 311 of the motor power supply relay 31. The contact 312 is driven to the closed state, and the battery power supply 4 is supplied to the motor drive unit 20 via the fuse 7 and the relay contact 312.

  The main control unit 10 includes an engine control unit (not shown), a power supply unit 11, a motor operation command unit 12, a data communication unit 13, and a forced energization control unit 14. An engine control unit (not shown) controls an engine (not shown) based on signals from various sensors 16-19. The power supply unit 11 receives supply of power from the battery power supply 4 to generate a stabilized power supply VC of, for example, 5 volts and supplies it to each circuit unit. The motor operation command unit 12 obtains the required rotational speeds of the motors 2 and 3 based on signals from various sensors (engine coolant temperature sensor 16, vehicle speed sensor 17, refrigerant pressure sensor 18) and air conditioner switch 19 signals. Then, data relating to the required rotation speed is supplied to the motor drive unit 20 via the data communication unit 13. The data communication unit 13 performs, for example, asynchronous data serial communication with the data communication unit 22 on the motor drive unit 20 side.

  The forced energization control unit 14 puts the forced energization unit 40 into a non-operating state in an initial state when the main control unit 10 is powered on. Specifically, energization to the excitation winding 411 of the forced energization relay 41 constituting the forced energization unit 40 is stopped. The forced energization control unit 14 controls the forced energization unit 40 to be in an operating state when abnormality information is supplied from the motor drive unit 20 via the data communication unit 13. Specifically, the excitation winding 411 of the forced energization relay 41 constituting the forced energization unit 40 is energized to drive the relay contacts 412 and 413 to the closed state. When the relay contacts 412 and 413 are closed, the battery power supply 4 is energized to the motors 2 and 3. Therefore, the motors 2 and 3 can be driven without using the motor drive unit 20. The motor operation command unit 12 determines whether to perform forced energization based on the content of the abnormality information, and forcibly drives the motors 2 and 3 via the forced energization control unit 14 and the forced energization unit 40. May be.

  The motor drive unit 20 includes a power supply unit 21, a data communication unit 22, a PWM control unit 23, an output stage drive unit 24, and an FET (field effect transistor) 25 as a semiconductor switching element that drives one of the motors 2. , An FET (field effect transistor) 26 as a semiconductor switching element for driving the other motor 3, temperature sensors 27 and 28 for detecting the temperatures of the FETs 25 and 26, and an output stage including the FETs 25 and 26, respectively. The abnormality detecting unit 29 for detecting the abnormality, the diode 8 for absorbing the counter electromotive voltage of one motor 2, and the diode 9 for absorbing the counter electromotive voltage of the other motor 3. In FIG. 1, a MOS type FET is exemplified as the semiconductor switching element, but a bipolar transistor, an insulated gate bipolar transistor, or the like may be used as the semiconductor switching element.

  The battery power supply 4 is supplied to the motor drive unit 20 and one terminal of each of the motors 2 and 3 via the contacts 712 of the fuse 7 and the power supply relay 31. The power supply unit 21 in the motor drive unit 20 receives supply of power from the battery power supply 4 to generate a stabilized power supply VCC of, for example, 5 volts and supplies it to each circuit unit. The data communication unit 22 performs, for example, asynchronous data serial communication with the data communication unit 13 on the main control unit 10 side.

  The PWM control unit 23 generates and outputs a PWM signal having a duty ratio corresponding to the requested rotation speed based on data relating to the requested rotation speed of the motor supplied from the main control unit 10 via the data communication unit 22. . The output stage driving unit 24 drives the gates of the FETs 25 and 26 based on the PWM signal supplied from the PWM control unit 23. As a result, the FETs 25 and 26 are switching-driven based on the PWM signal, and the power supplied to the motors 2 and 3 is PWM-controlled.

  The abnormality detection unit 29 includes an overvoltage detection unit 291, an overcurrent detection unit 292, an overtemperature detection unit 293, and an operation abnormality detection unit 294. The overvoltage detection unit 291 monitors the voltage supplied to the FETs 25 and 26, and outputs overvoltage detection information when it exceeds a preset allowable voltage. The overvoltage detection unit 291 detects an overvoltage by comparing a voltage obtained by dividing the voltage supplied to each of the FETs 25 and 26 by a resistance voltage dividing circuit with a preset threshold voltage using a comparator or the like. You may do it. The overvoltage detection unit 291 A / D converts the voltage obtained by dividing the voltage supplied to the FETs 25 and 26 by the resistance voltage dividing circuit through the A / D converter, and the A / D converted voltage data. The overvoltage may be determined based on the above.

  The overcurrent detection unit 292 monitors the current (motor current) flowing through the FETs 25 and 26 based on the ON voltage when the FETs 25 and 26 are in the ON state. Output detection information. The current (motor current) flowing through each FET 25, 26 is detected based on the voltage generated at both ends of the current detection resistor by connecting a current detection resistor in series with each FET 25, 26. It may be.

  The overtemperature detection unit 293 monitors the temperature of each FET 25, 26 based on the output of each temperature sensor 27, 28, and outputs overtemperature detection information when it exceeds a preset allowable temperature. The temperature sensors 27 and 28 are provided in the vicinity of the FETs 25 and 26. Each of the temperature sensors 27 and 28 is configured using a heat sensitive resistance element such as a thermistor. Each of the temperature sensors 27 and 28 may be configured by using a diode, and the temperature may be detected from the temperature characteristic of the forward voltage drop of the diode.

  The operation abnormality detector 294 is driven when the ON voltage (drain-source voltage in the ON state) of each of the FETs 25 and 26 when being driven in the ON state exceeds a preset allowable value and in the OFF state. When the drain voltage or leakage current of each of the FETs 25 and 26 is lower than a preset allowable value, operation abnormality information indicating that the switching operation of the switching element is abnormal is output. Further, when the current is detected by the shunt resistor and the allowable value is exceeded, it may be detected and output.

  When any one of overvoltage, overcurrent, overtemperature, and operation abnormality is detected, the abnormality detection unit 29 supplies the abnormality information to the main control unit 10 side via the data communication unit 22 and outputs the abnormality information to the PWM. It supplies to the control part 23. When the abnormality information is supplied, the PWM control unit 23 stops outputting the PWM signal, and drives the FETs 25 and 26 to the off state via the output stage driving unit 24.

  In a normal operation state in which none of overvoltage, overcurrent, overtemperature, and operation abnormality is detected, the abnormality detection unit 29 sends normal information to the main control unit via the data communication unit 22 in a preset cycle (for example, 1 second cycle). Supply to 10 side.

  Next, the operation of the first embodiment will be described. When the ignition switch 5 is turned on, the battery power 4 is supplied to the main controller 10, the relay 31 is driven, and the battery power 4 is supplied to the motor driver 20. The required rotation speed of each of the motors 2 and 3 is obtained by the motor operation command section 12 in the main control section 10, and data (operation command) relating to the requested rotation speed is supplied to the motor drive section 20 via the data communication section 13. . The PWM control unit 23 in the motor drive unit 20 obtains a duty ratio corresponding to the requested rotational speed by referring to a correspondence table between the rotational speed and the duty ratio and generates a PWM signal having a duty ratio corresponding to the requested rotational speed. The FETs 25 and 26 are driven via the output stage drive circuit 24. The duty ratio corresponding to the required rotation speed may be obtained on the motor operation command unit 12 side, and the duty ratio may be supplied to the motor drive unit 20 side. As a result, the motors 2 and 3 are rotated at the required rotational speed, and the cooling fans (not shown) are rotated. Note that when starting the motors 2 and 3, the PWM control unit 23 performs soft start processing that gradually increases the duty ratio of the PWM signal so as to reduce the inrush current at the time of starting the motor. Yes.

  The abnormality detection unit 29 continuously monitors the operation states of the FETs 25 and 26 that drive the motors 2 and 3, and if an overvoltage, overcurrent, overtemperature, or operation abnormality is detected, an abnormality in the output stage is detected. Is supplied to the main control unit 10 via the data communication unit 22.

  FIG. 2 is a flowchart showing a motor forced energization process for an abnormality of the motor drive unit. When the forced energization control unit 14 in the main control unit 10 receives data supplied from the motor drive unit 20 via the data communication unit 13 (step S1), the output of the motor drive unit 20 based on the received data. It is determined whether or not the stage is abnormal (step S2). And when abnormality information is received, the battery power supply 4 is supplied to each motor 2 and 3 via the forced electricity supply part 40 (step S3). As a result, the motors 2 and 3 are forcibly driven without using the motor drive unit 20. Therefore, even if an abnormality occurs in the operation of the motor drive unit 20 while the vehicle is running, the operation of each fan motor can be continued.

  The forced energization control unit 14 may cancel the forced energization state after forcibly energizing the motors 2 and 3 for a predetermined time when the abnormality information is received. For example, if the overtemperature of the FETs 25 and 26 of the motor drive unit 20 is eliminated, the motors 2 and 3 can be driven by the motor drive unit 20. Furthermore, the forced energization control unit 14 may count the number of times of forced energization for a predetermined time, and may continue the forced energization state when the predetermined number of times (for example, 3 times) is reached.

  When normal information is not supplied from the motor drive unit 20 after a predetermined time has elapsed, the forced energization control unit 14 determines that an abnormality has occurred in the operation of the motor drive unit 20 or the data communication unit 13. The motors 2 and 3 may be driven by forced energization via the forced energization unit 40.

  When the motors 2 and 3 are driven by forced energization, the main control unit 10 may cause a display unit (not shown) to display that the motor driving unit 20 has an abnormality. The main control unit 10 may supply abnormality information to a vehicle diagnosis apparatus (not shown) and store the occurrence date and time of the abnormal state of the motor drive unit 20 and the content of the abnormality.

  FIG. 3 is a block diagram showing another embodiment of the electric fan control device according to the present invention. An electric fan control device 50 shown in FIG. 3 is obtained by adding a power cutoff unit 30, a current detection unit 35, and a power cutoff control unit 15 to the electric fan control device 1 shown in FIG.

  In the initial state where the ignition switch 5 is turned on and the battery power 4 is supplied to the main control unit 10, the power cutoff control unit 15 turns on the excitation winding 311 of the motor power supply relay 31 that constitutes the power cutoff unit 30. Control to energized state. As a result, the relay contact 312 is closed, and the battery power supply 4 is supplied to the motors 2 and 3 and the motor drive unit 20.

  The power shut-off control unit 15 is in a state where the current supplied to the motors 2 and 3 and the motor drive unit 20 detected by the current detection unit 35 exceeds a preset allowable value (for example, a large current value associated with motor locking). Is continued for a predetermined time, the power shut-off unit 30 is controlled to be shut off. Specifically, energization to the excitation winding 311 of the motor power supply relay 31 is stopped, the relay contact 312 is opened, and the power supply to the motors 2 and 3 and the motor drive unit 20 is shut off.

  When the abnormality information is supplied from the motor drive unit 20 side, the power cutoff control unit 15 controls the power cutoff unit 30 to be in a cutoff state. When the forced energization controller 14 forcibly energizes each of the motors 2 and 3, the power shutoff controller 15 controls the power interrupter 30 to the energized state and controls the motor current based on the output of the current detector 35. When the state where the supply current to each motor 2 and 3 exceeds a preset allowable value (for example, a large current value associated with the motor lock) continues for a predetermined time, the power shut-off unit 30 is turned off. Control. Therefore, even if the motors 2 and 3 are forcibly energized via the forced energization unit 40, the power supply is cut off if an overcurrent occurs due to a motor lock or motor winding short circuit. can do.

  The current detector 35 uses a current transformer (current transformer) or a configuration that detects a magnetic flux generated by a current. The current detection unit 35 may be configured to include a current detection resistor.

  FIG. 4 is a block diagram showing still another embodiment of the electric fan control device according to the present invention. FIG. 4 shows an example in which the motor drive control device according to the present invention is applied to blower fan control of an automotive air conditioner. An electric fan control device 60 shown in FIG. 4 includes a main control unit 70 including an automatic air conditioner electronic control unit (auto air conditioner ECU), a direct current motor (hereinafter referred to as a motor) 62 that drives a blower fan (not shown), and a motor drive. Unit 80, power shut-off unit 30, and forced energization unit 90.

  A motor operation commanding unit 71 in the main control unit 70 determines a requested rotational speed of the motor 62 for driving the blower fan based on setting conditions of an air conditioner operation panel unit (not shown), and transmits data relating to the requested rotational speed to the data communication unit 72. To the motor drive unit 80. The PWM control unit 81 in the motor driving unit 80 generates a PWM signal having a duty ratio corresponding to the requested rotation speed based on the data regarding the requested rotation speed received via the data communication unit 82, and outputs the output stage driving unit 83. The FET 25 is driven to switch through Thereby, the electric power supplied to the motor 62 is PWM-controlled, and the rotation speed of the motor 62 is controlled.

  The abnormality detection unit 84 continuously monitors the operation state of the FET 25 that drives the motor 62, and the detection units 841, 842, 843, 844 detect overvoltage, overcurrent, overtemperature, and switching operation abnormality. Then, information indicating the abnormality of the output stage (abnormal information) is supplied to the main control unit 70 side via the data communication unit 82.

  Bidirectional serial data communication is performed between the data communication units 72 and 82 by the asynchronous method via the data line (BUS) 100. The communication protocol is compliant with LIN (Local Interconnect Network).

  When the power cutoff control unit 73 in the main control unit 70 receives the abnormality information, the power cutoff unit 30 puts the power cutoff unit 30 into a power supply cutoff state for a predetermined time (for example, several seconds), and then restarts the power supply. The motor operation commanding unit 71 determines that the motor driving unit 80 is in a state where it cannot operate normally when abnormality information is supplied from the motor driving unit 80 side even after the power supply to the motor driving unit 80 is resumed. Then, the forced energization control unit 74 is activated. The forced energization control unit 74 drives the contact point 912 of the relay 91 to a closed state by controlling the excitation winding 911 of the relay 91 constituting the forced energization unit 90 to be in an energized state. As a result, the motor 62 is energized via the contact point 912 of the relay 91 and the motor 62 is driven. The power cut-off unit 73 monitors the motor current based on the output of the current detection unit 35, and controls the power cut-off unit 30 to a cut-off state when a state exceeding a preset allowable value continues for a predetermined time.

  In addition, in each Example, although the example which comprises the forced electricity supply parts 40 and 90 using the relays 41 and 91 was shown, you may comprise the forced electricity supply parts 40 and 90 using a semiconductor switching element.

  In addition, a relay contact or a semiconductor switching element is provided on the upstream side of the power input terminal portion of the motor drive units 20 and 80, and the forced energization is performed to the motors 2 and 62 via the forced energization units 40 and 90. In the state, the power supply to the motor drive units 20 and 80 may be stopped by driving the relay contact or the semiconductor switching element to the OFF state. Thereby, the power consumption in the motor drive units 20 and 80 can be eliminated.

  Further, in the forced energization state, all the connections between the terminals of the motors 2 and 62 and the motor drive units 20 and 80 may be blocked using a plurality of relay contacts or the like. As a result, the motors 2 and 62 can be driven by forced energization without being affected by the operating state on the motor drive units 20 and 80 side.

  Moreover, in each Example, although the structure which transmits / receives various information, such as a driving | operation command and abnormality information, was shown by serial data communication between the main control parts 10 and 70 and the motor drive parts 20 and 80, a voltage signal, Various information may be transmitted and received using a frequency signal, a pulse width signal, or the like.

  In addition, although each Example showed about the electric fan motor control for motor vehicles, the electric fan control apparatus which concerns on this invention is applicable to various uses other than a motor vehicle.

It is a block diagram of an electric fan control device. (Example 1) It is a flowchart of a motor forced energization process. It is a block diagram of an electric fan control device. (Example 2) It is a block diagram of an electric fan control device. Example 3

Explanation of symbols

1, 50, 60 Electric fan control device 2, 3, 62 Motor 4 Battery power supply 10, 70 Main control unit 12, 71 Motor operation command unit 13, 22, 72, 82 Data communication unit 14, 74 Forced energization control unit 15, 73 Power-off control unit 20, 80 Motor drive unit 23, 81 PWM control unit 25, 26 Semiconductor switching element (FET)
27, 28 Temperature sensor 29, 84 Abnormality detection unit 30 Power supply cutoff unit 35 Current detection unit 40, 90 Forced energization unit

Claims (2)

A motor that drives the fan;
Based on the operation command supplied from the main control unit, the switching operation of one or more semiconductor switching elements is controlled to control the power supplied to the motor, and the abnormality detecting unit detects an abnormality in the operation state of the semiconductor switching element. A motor drive unit for supplying abnormality information to the main control unit when detected;
A forced energization section for forcibly energizing the motor;
A main control unit that supplies an operation command to the motor drive unit and controls the forced energization unit to be in a forced energization state or a forced energization state for a predetermined time when abnormality information is supplied from the motor drive unit; An electric fan control device. The electric fan control device according to claim 1, wherein the abnormality detection unit outputs abnormality information when any of overcurrent, overvoltage, and overtemperature of the semiconductor switching element is detected.

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