JP2013009511A - Cooling system and cooling fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling system which can more appropriately control a rotation of a cooling blower.SOLUTION: The cooling system for cooling on-vehicle electrical equipment by using a cooling blower 12 includes the cooling blower 12 and a vehicle ECU 10 which outputs a target rotation speed to the cooling blower 12. The cooling blower 12 includes a fan unit 26 having blade members which blow air by being rotated, a motor 24 for rotating/driving the fan unit, a rotation speed sensor 30 for detecting a rotation speed of the motor 24, and a control microcomputer 22 for feedback-controlling the rotating/driving of the motor on the basis of the target rotation speed from the vehicle ECU 10 and an actual rotation speed detected by the rotation speed sensor 30.

Description

  The present invention relates to a cooling blower that cools an in-vehicle electric device, for example, a battery, and a cooling system that cools the electric device using the cooling blower.

  Some electric devices mounted on a vehicle generate a large amount of heat when driven. Such heat may cause deterioration of the electric device or other peripheral electric devices. For example, instead of the engine or in addition to the engine, an electric vehicle or a hybrid vehicle equipped with a traveling motor is equipped with a high-voltage battery that supplies driving power to the traveling motor. Such a high-voltage battery generates heat during charging / discharging and becomes high temperature, and as a result, the battery may deteriorate. In order to prevent the deterioration of the electrical equipment due to such high temperature, the vehicle is usually equipped with a cooling blower for cooling the electrical equipment.

  Normally, the rotation speed of such a cooling blower is controlled by a vehicle ECU (Electronic Control Unit). The vehicle ECU calculates the target rotational speed of the cooling blower necessary for cooling the target device based on the temperature of the cooling target device (for example, a high-voltage battery) or the temperature of the air sucked into the blower. Then, the vehicle ECU calculates and outputs a command rotational speed to be output to the cooling blower based on the obtained target rotational speed and the actual rotational speed output from the cooling blower. That is, conventionally, the rotational speed of the cooling blower has been feedback controlled in the vehicle ECU.

JP 2006-213210 A

  However, normally, the actual rotational speed of the cooling blower is rarely output to the vehicle ECU as it is, and is input to the vehicle ECU through signal conversion such as DA conversion and AD conversion because of passing through several relay devices. . During this signal conversion, errors are accumulated, and the difference between the actual rotational speed input to the vehicle ECU and the actual actual rotational speed may eventually increase. As a result, appropriate feedback control could not be performed, resulting in insufficient rotation or excessive rotation.

  In Patent Document 1, various signals from an intake air temperature sensor, a battery temperature sensor, a vehicle speed sensor, a blower speed sensor for detecting a blower speed of an air conditioner, and the like are processed, and power supply ON / OFF and rotation speed control of the battery cooling fan are processed. A technique for performing is disclosed. However, even in this technique, since the control of the battery cooling blower is performed by the control unit, the above-described problem may occur.

  Therefore, an object of the present invention is to provide a cooling blower and a cooling system that can more appropriately control the rotation of the cooling blower.

  A cooling system according to the present invention is a cooling system that cools an in-vehicle electric device using a cooling blower, the cooling blower that cools the electric device mounted on the vehicle by blowing air, and a target rotation with respect to the cooling blower A vehicle ECU that outputs a number, and the cooling blower includes a fan unit that includes a wing member that blows air by rotating, a motor that rotationally drives the fan unit, and a rotation that detects the number of rotations of the motor And a control unit that feedback-controls the rotational drive of the motor based on the target rotational speed from the vehicle ECU and the actual rotational speed detected by the rotational speed detection means.

  In a preferred aspect, the monitoring unit that AD-converts the analog signal indicating the rotational speed output from the cooling blower and outputs the analog signal to the vehicle ECU, and the actual unit that is provided in the cooling blower and detected by the rotational speed detection means. DA conversion means for DA-converting a digital signal indicating the rotational speed and outputting it to the monitoring unit. In another preferred aspect, the control unit supplies power to the motor when a current value exceeding a second threshold value lower than a second threshold value defined to cut off the power supply to the motor is detected. Switch to current suppression control to suppress the current value.

  Another cooling blower according to the present invention is a cooling blower that cools an on-vehicle electric device by blowing air, a fan unit that includes a wing member that blows air by rotating, a motor that rotationally drives the fan unit, A rotational speed detection means for detecting the rotational speed of the motor; a control section for feedback-controlling the rotational drive of the motor based on the target rotational speed sent from the vehicle ECU and the actual rotational speed detected by the rotational speed detection means; Is provided.

  According to the present invention, since the drive of the motor is feedback controlled by a control microcomputer provided in the cooling blower instead of the vehicle ECU, an error associated with signal conversion can be prevented, and the rotation of the cooling blower can be controlled more appropriately. .

It is a schematic block diagram of the cooling system which is embodiment of this invention. It is a flowchart which shows the flow of the cooling system drive in this embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a cooling system according to an embodiment of the present invention. This cooling system is a cooling system mounted on a vehicle, for example, an electric vehicle or a hybrid vehicle, and is a cooling system for cooling a high-voltage battery (not shown) that supplies electric power to a traveling motor.

  In the present embodiment, the high-voltage battery that supplies power to the traveling motor is targeted for cooling. However, if the electric device is mounted on a vehicle and needs to be cooled, other electric devices such as capacitors and fuels are used. A battery, an inverter, or the like may be a cooling target.

  The cooling system includes a cooling blower 12 that cools a high-voltage battery (an electric device to be cooled) by blowing air, a vehicle ECU 10 that controls driving of an in-vehicle electric device such as the cooling blower 12, and various electric devices that are controlled by the vehicle ECU 10. A monitoring unit 18 that collects the state of the equipment and sends it to the vehicle ECU 10, an auxiliary battery (not shown) that supplies power to the cooling blower 12, and the like are provided.

  The cooling blower 12 cools a high-voltage battery, which is an electrical device to be cooled, by blowing air. The cooling blower 12 includes a fan unit 26, a drive motor 24, a control microcomputer 22, a rotation speed sensor 30, a DA converter 32, and the like. The fan unit 26 is a wing member mechanism that blows air as it rotates. An output shaft of the drive motor 24 is connected to the rotation shaft of the fan unit 26, and air is blown from the fan unit as the drive motor 24 is driven.

  The rotational speed of the drive motor 24 is detected by the rotational speed sensor 30. A digital signal indicating the actual rotational speed output from the rotational speed sensor 30 is output to the control microcomputer 22 and the DA converter 32. As the rotation speed sensor 30, for example, a Hall element, a resolver, an encoder, or the like can be used. The DA converter 32 converts the output from the rotation speed sensor 30, which is a digital signal, into an analog signal (voltage signal) and outputs the analog signal (voltage signal) to the monitoring unit 18.

  The control microcomputer 22 controls the drive of the drive motor 24 based on an instruction from the vehicle ECU 10. The target rotational speed of the drive motor 24 is sent from the vehicle ECU 10 to the control microcomputer 22 as a duty signal. The control microcomputer 22 feedback-controls the drive motor 24 so as to rotate at the target rotational speed. That is, the control microcomputer 22 calculates a command rotation speed according to the difference between the target rotation speed and the actual rotation speed, and controls energization to the drive motor 24 with a duty ratio according to the command rotation speed. Further, the control microcomputer 22 is provided with a memory 28, and failure information and the like are recorded in the memory 28.

  Further, the control microcomputer 22 compares the current value supplied to the drive motor 24 with the first threshold value stored in the memory 28, and changes the feedback control condition according to the comparison result. Will be described in detail later.

  The monitoring unit 18 is a unit that collects information on various electric devices that are controlled by the vehicle ECU 10 including the cooling blower 12 and outputs the information to the vehicle ECU 10. Regarding the control of the cooling blower 12, the monitoring unit 18 converts an analog signal representing the actual rotational speed input from the cooling blower 12 into a digital signal by the AD converter 34 and outputs the digital signal to the vehicle ECU 10. In addition to the actual rotational speed of the cooling blower 12, the monitoring unit 18 also includes the temperature of the high-voltage battery, the temperature of the air sucked by the cooling blower 12 (intake air temperature), the voltage value of the auxiliary battery as a power source, and the like. Collected and sent to the vehicle ECU 10.

  The vehicle ECU 10 controls driving of various electric devices mounted on the vehicle including the cooling blower 12. Specifically, the vehicle ECU 10 controls the state of charge of the high-voltage battery, or controls the rotating electrical machine and various electric devices mounted on the vehicle according to the state of the vehicle.

  The control of the cooling blower 12 will be described. The vehicle ECU 10 calculates a new target rotational speed of the cooling blower 12 based on the temperature of the high voltage battery, the intake air temperature, the voltage value of the auxiliary battery, and the like. Then, a duty ratio signal representing the target rotational speed is output to the cooling blower 12. As described above, the control microcomputer 22 of the cooling blower 12 feedback-controls the drive motor 24 according to the target rotational speed.

  Further, the vehicle ECU 10 also determines whether or not there is an abnormal operation of the cooling blower 12 based on the current target rotational speed, the actual rotational speed sent from the monitoring unit 18, and the like. When an operation abnormality occurs, the vehicle ECU 10 records the values of various parameters at that time in the memory 20 as fault information.

  The operation of the cooling system as described above will be described in comparison with a conventional cooling system. First, a conventional cooling system will be briefly described. The conventional cooling system is not provided with a control microcomputer, and the vehicle ECU directly controls the rotational speed. In other words, the vehicle ECU calculates a command rotation speed based on the calculated target rotation speed and a difference value between the actual rotation speed input from the monitoring unit, and a command duty ratio to drive at the command rotation speed. Was output to the motor drive circuit. That is, conventionally, feedback control has been performed in the vehicle ECU.

  However, the conventional configuration has a problem that an error in the actual rotational speed input to the vehicle ECU is large. That is, in the conventional configuration, the rotational speed of the motor is detected by the rotational speed sensor and then DA-converted by the DA converter provided in the cooling blower. The rotation speed signal converted into the analog signal is input to the monitoring unit. Then, the monitoring unit converts the input rotation speed signal into a digital signal again by the AD converter, and inputs it to the vehicle ECU. As described above, in the conventional configuration, the actual rotational speed is input to the vehicle ECU through DA conversion and AD conversion. However, an error occurs during the signal conversion, and as a result, is input to the vehicle ECU. The problem was that the error in the actual rotational speed was large. As a result, the command rotational speed cannot be calculated properly, and problems such as insufficient rotational speed and excessive rotational speed have occurred. In addition, when the number of rotations is insufficient, naturally, there is a problem that the cooling capacity is insufficient and the electric device cannot be sufficiently cooled. Further, when the rotational speed is excessive, undesirable vibrations and noises may occur.

  Here, if the rotational speed detected by the rotational speed sensor of the cooling blower is directly input to the vehicle ECU without using the monitoring unit, the above problem can be avoided. However, as described above, the vehicle ECU controls the driving of many devices, not limited to the cooling blower. There has been a demand for not increasing the number of signal lines connected to the vehicle ECU as much as possible.

  Therefore, in the present embodiment, in order to appropriately control the rotation speed of the drive motor 24 while preventing an increase in signal lines connected to the vehicle ECU, a control microcomputer 22 is provided, and the control microcomputer 22 performs feedback control. I try to do it. The flow of drive control of the cooling blower 12 in this embodiment will be described with reference to FIG.

  When driving the cooling blower 12, first, the vehicle ECU 10 calculates the target rotational speed (S10). As described above, the target rotational speed is calculated based on the temperature of the high-voltage battery that is the cooling target, the intake air temperature, and the voltage value of the auxiliary battery that supplies power to the cooling battery. The calculated target rotational speed is input to the control microcomputer 22 of the cooling blower 12 as a duty signal corresponding to the rotational speed (S12).

  The control microcomputer 22 feedback-controls the drive motor 24 based on the input target rotational speed and the actual rotational speed output from the rotational speed sensor 30 (S14). That is, the command rotational speed is calculated according to the difference between the target rotational speed and the actual rotational speed, and the energization to the drive motor 24 is controlled with the duty ratio corresponding to the command rotational speed.

  Here, the signal indicating the actual rotational speed input to the control microcomputer 22 is directly input from the rotational speed sensor 30 without being subjected to DA conversion or AD conversion. As a result, an error associated with signal conversion is not included, and the current state of the drive motor 24 is accurately represented. As a result, the rotational speed of the drive motor 24 can be controlled with higher accuracy, and insufficient rotation and excessive rotation can be effectively prevented.

  Also in this embodiment, as in the conventional system, the actual rotational speed detected by the rotational speed sensor 30 is input to the vehicle ECU 10 via the monitoring unit 18 (through DA conversion and AD conversion). However, in the present embodiment, the vehicle ECU 10 uses the actual rotational speed only for determining whether there is an abnormal operation, and does not use it for controlling the rotational speed of the drive motor 24. That is, for example, when the signal representing the actual rotational speed is not input from the monitoring unit 18 or the difference value between the actual rotational speed input from the monitoring unit 18 and the target rotational speed output to the cooling blower 12 is excessive. In this case, it is determined that an operation abnormality has occurred, but the actual rotational speed input from the monitoring unit 18 is not used for calculation of the target rotational speed.

  As is clear from the above description, according to the present embodiment, the cooling blower 12 is provided with the control microcomputer 22 that performs self-feedback control of the rotation of the drive motor 24, and the control microcomputer 22 is provided with the actual rotational speed that is the feedback amount. Enter directly. As a result, it is possible to eliminate the occurrence of errors associated with AD conversion and DA conversion of the actual rotational speed, and as a result, the cooling blower 12 can be driven and controlled more appropriately.

  In the present embodiment, the control content of the drive motor 24 is switched by the current value supplied to the drive motor 24. That is, as described above, the control microcomputer 22 controls the current to be reduced when a current value exceeding the first threshold value D1 recorded in the memory 28 is detected as a current value to be supplied to the drive motor 24. Switch to. This is due to the following reason.

  Conventionally, in a mode in which the control microcomputer 22 is not provided, an excessive current value that may cause a failure of the drive motor 24 or a power supply circuit (not shown) to the drive motor 24, for example, a rated current value of the drive motor 24 When a current value exceeding this value flows, the energization to the drive motor 24 is automatically cut off by the protection circuit provided in the energization circuit. And by having such a structure, it was possible to effectively prevent a failure of the drive motor 24 and the like. However, in the case of only overcurrent countermeasures by such a protection circuit, energization is immediately cut off when an overcurrent value exceeding a threshold value (hereinafter referred to as “second threshold value”) set in the protection circuit is detected. In other words, even if it is a temporary overcurrent, if the second threshold value is exceeded, the energization is immediately interrupted and an error occurs. As a result, there is a problem that errors tend to occur frequently.

  In this embodiment, in order to reduce such a problem, the control microcomputer 22 sets a first threshold value that is lower than the second threshold value, and if a current value exceeding the first threshold value is detected, the current is immediately Switching to current suppression control, which is control to narrow down, is performed. This switching of control is realized, for example, by changing the values of various gains used in the feedback control from values set for normal control to values set for current suppression. The control microcomputer 22 records in the memory 28 as one piece of failure information that a relatively high current value exceeding the first threshold has been detected.

  When the current value exceeds the second threshold value despite the current suppression control, the energization is cut off by the protection circuit. In this case, the driving of the cooling blower 12 is forcibly stopped. In this case, the control microcomputer 22 outputs a signal indicating an error to the vehicle ECU 10 via the monitoring unit 18. The vehicle ECU 10 notifies the user of warning information as appropriate.

  On the other hand, if the current value becomes less than the first threshold as a result of executing the current suppression control, the control is changed to normal control (eg, a gain set for normal control is used as a gain used for control). Thereafter, the cooling blower 12 is continuously driven. Therefore, if the overcurrent is temporary, the driving of the cooling blower 12 is continued without being stopped. In addition, if the state below 1st threshold value and less than 2nd threshold value continues, the drive of the cooling blower 12 by current suppression control will be continued fundamentally. However, if this state continues excessively, for example, a time during which damage to the circuit or the drive motor 24 is estimated, and if it continues, the drive motor 24 is returned to, similarly to the case where the second threshold is exceeded. May be turned off and an error may be output.

  In any case, the control microcomputer 22 is provided in the cooling blower 12 as described above, and the current control is switched to a current suppression control when a relatively high current value is detected although it does not satisfy the second threshold value (current value to cut off the energization). As a result, it is possible to effectively prevent the current value from exceeding the second threshold value, and consequently to reduce the number of occurrences of errors. In the present embodiment, two types of threshold values (first threshold value and second threshold value) used for overcurrent countermeasures are used. In this embodiment, when the second threshold value is exceeded, the energization is forcibly interrupted by the protection circuit, but the energization may be interrupted by control on the control microcomputer 22 side.

  As described above, according to this embodiment, the control microcomputer 22 is provided in the cooling blower 12, and the drive motor 24 is feedback-controlled by the control microcomputer 22. As a result, since the actual rotational speed that does not include an error associated with signal conversion can be used for feedback control as it is, the control accuracy can be further improved. Further, by controlling the drive motor 24 with the control microcomputer 22, it is possible to take measures against overcurrent at a stage before the energization is cut off, and stop driving the cooling blower 12 due to the overcurrent. The occurrence of errors can be reduced.

  DESCRIPTION OF SYMBOLS 10 Vehicle ECU, 12 Cooling blower, 18 Monitoring unit, 20, 28 Memory, 22 Control microcomputer, 24 Drive motor, 26 Fan unit, 30 Speed sensor, 32 DA converter, 34 AD converter.

Claims (4)

A cooling system that cools in-vehicle electrical equipment using a cooling blower,
A cooling blower that cools electrical equipment mounted on the vehicle by blowing air;
A vehicle ECU that outputs a target rotational speed to the cooling blower;
With
The cooling blower is
A fan unit including a wing member that blows air by rotating;
A motor that rotationally drives the fan unit;
A rotational speed detection means for detecting the rotational speed of the motor;
A control unit that feedback-controls the rotational drive of the motor based on the target rotational speed from the vehicle ECU and the actual rotational speed detected by the rotational speed detection means;
A cooling system comprising: The cooling system of claim 1, further comprising:
A monitoring unit that AD-converts an analog signal indicating the rotational speed output from the cooling blower and outputs the analog signal to the vehicle ECU;
DA conversion means that is provided in the cooling blower and DA-converts a digital signal indicating the actual rotational speed detected by the rotational speed detection means and outputs the digital signal to the monitoring unit;
A cooling system comprising: The cooling system according to claim 1 or 2,
The control unit suppresses a current value that suppresses a current value supplied to the motor when a current value that exceeds a second threshold value that is lower than a second threshold value that is defined to cut off the power supply to the motor is detected. A cooling system characterized by switching to control. A cooling blower that cools in-vehicle electrical equipment by blowing air,
A fan unit including a wing member that blows air by rotating;
A motor that rotationally drives the fan unit;
A rotational speed detection means for detecting the rotational speed of the motor;
A control unit that feedback-controls the rotational drive of the motor based on the target rotational speed sent from the vehicle ECU and the actual rotational speed detected by the rotational speed detection means;
A cooling blower comprising:

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