JP2005033963A - Fan motor control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform appropriate operation control for a detected failure condition by making a control means for integrally controlling a fan motor controller positively detect an operation failure condition of the fan motor. <P>SOLUTION: A microcomputer 2 for control outputs a PWM signal as a control signal to a fan motor control means 3 for performing feed control to the fan motor FM, when a fan motor current value detected by rent detection means 5 reaches a first current value. In the microcomputer 2, control for reducing a duty ratio of the PWM signal is performed to drop feed voltage to the fan motor FM from the fan control means 3, thus performing control for inhibiting fan motor current; and, when the fan motor current suddenly increases and reaches a second current value before reduction control of the PWM signal with the microcomputer 2 for control is executed, a current limiting means 7 immediately opens in hardware, an inflow current into the fan motor control means 3 is inhibited to prevent the fan motor control means 3 from being damaged, resulting in impossible feed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fan motor control device that performs drive control of a fan motor used for ventilation of a combustion device, and more particularly to a technique for accurately detecting an abnormality and improving the reliability of a protection operation when the fan motor is abnormal.

  For example, in a DC fan motor control method, a fan motor control instruction signal is transmitted from a microcomputer to a fan motor control circuit, and a voltage corresponding to the instruction signal is applied to the fan motor. At that time, the current flowing through the fan motor is configured such that a signal converted into a voltage by the current detection unit is fed back to the fan motor control circuit in hardware, and a constant current flows (for example, Patent Document 1). reference.).

JP-A-8-266080

  In addition, as a method of detecting an abnormality of the fan motor, a method of monitoring the rotational speed of the fan motor with a microcomputer and determining that this is out of the predetermined appropriate rotational speed range is a general technique. When it is determined that the fan motor is abnormal, the fan motor operation is stopped under the control of the microcomputer, and this abnormality is reported.

  As described above, the fan motor current actually flowing to the fan motor is merely fed back to the fan motor control circuit in hardware, and the microcomputer indicates that the fan motor current increases due to the abnormality of the fan motor. Is unrecognizable. For this reason, if the current to the fan motor increases due to load fluctuations, the applied voltage to the fan motor is reduced by the operation of the fan motor control circuit based on the current feedback even if there is no danger due to this current increase. If the rotational speed of the motor is outside the range of the appropriate rotational speed, the microcomputer may determine that this is a fan motor abnormality and may stop the fan motor operation.

  The problem of the present invention is that the control means for comprehensively controlling the fan motor control device accurately detects the abnormal operation state of the fan motor and enables proper operation control for the detected abnormal state. It is to improve the reliability as a device.

  In order to solve the above-mentioned problems, the invention according to claim 1 is a control means for comprehensively controlling driving / stopping of the fan motor, and a voltage based on a control signal from the control means is applied to the fan motor. And a fan motor control device for controlling the applied voltage to the fan motor so as to make the fed back applied voltage coincide with the voltage based on the control signal. Current detecting means for detecting the fan motor current to be detected, and the control means for receiving the fan motor current value detected by the current detecting means has a first current value determined in advance as an abnormal fan motor current value exceeding an appropriate range. Non-volatile storage means for storing, and the first electric power stored in the non-volatile storage means are the fan motor current values detected by the current detection means. An abnormality determination unit that determines an abnormal state that has reached a value, and an abnormal-time operation control that changes a control signal to the fan motor control unit so as to reduce the voltage applied to the fan motor based on the abnormality determination by the abnormality determination unit. And means.

  According to a second aspect of the present invention, in the fan motor control device according to the first aspect of the present invention, the fan motor current value flowing through the fan motor is a second current determined in advance as a value larger than the first current value. When the value reaches the value, it operates as a hardware and is provided with a current limiting means for limiting the feedback current to the fan motor control means. Even when the fan motor current value reaches the second current value due to a sudden increase in current before the control signal is changed, the feedback current to the fan motor control means is reduced below the second current value by the current limiting means. It is characterized by being restricted.

  According to a third aspect of the present invention, in the fan motor control device according to the first or second aspect, the abnormal operation control means of the control means has a fan motor current value detected by the current detection means. The control signal to the fan motor control means is changed so as to be lower than the first current value.

  According to a fourth aspect of the present invention, in the fan motor control device according to any one of the first to third aspects, the abnormality determination means determines an abnormal state based on the determination of the abnormal state. An abnormality notifying means for notifying abnormality is provided.

  According to the fan motor control device of the first aspect, the non-volatile storage means for storing the first current value determined in advance as the abnormal fan motor current value exceeding the appropriate range, and the fan motor current detected by the current detection means. An abnormality determination unit that determines an abnormal state in which the value has reached the first current value stored in the nonvolatile storage unit, and a voltage applied to the fan motor is reduced based on the abnormality determination by the abnormality determination unit. Since the control means includes an abnormal operation control means for changing the control signal to the fan motor control means, the fan motor current value detected by the current detection means is used as a reference instead of the rotation speed of the fan motor. It is possible to perform an abnormality determination, and when an abnormality in the fan motor current is determined, the fan voltage is reduced so as to reduce the voltage applied to the fan motor. By changing the control signal to be transmitted to over motor control means, the voltage applied to the fan motor is reduced, it is possible to reduce the fan motor current to the normal range. That is, it is possible to improve the reliability of the device by accurately detecting the operation state of the fan motor and making the fan motor control device capable of appropriate operation control.

  According to the fan motor control device of the second aspect, the fan motor current value flowing through the fan motor reaches a second current value determined in advance as a value larger than the first current value, so that By providing a current limiting means that operates and limits the feedback current to the fan motor control means, the abnormality determination means of the control means makes an abnormality determination, and the control signal to the fan motor control means is changed by the abnormal operation control means. Even if the fan motor current value reaches the second current value due to a sudden increase in current before being performed, the feedback current to the fan motor control means is limited to the second current value or less by the current limiting means, and the fan motor control is performed. It can be effectively avoided that the means is damaged and the fan motor cannot be operated. Thereby, it becomes possible to further improve the reliability as a fan motor control device.

  According to the fan motor control device of the third aspect, the abnormal operation control means of the control means is configured so that the fan motor current value detected by the current detection means falls below the first current value and falls within an appropriate range. Thus, since the control signal to the fan motor control means is changed, it is possible to automatically shift to the proper operation following avoidance of damage due to the fan motor abnormality. Thereby, it becomes possible to further improve the reliability as a fan motor control device.

  According to the fan motor control device of the fourth aspect, since the abnormality notifying means for notifying the abnormality of the fan motor is provided based on the fact that the abnormality determining means determines the abnormal state, when the control means is abnormal It can be notified that the control signal to the fan motor control means has been changed by the intervention of the operation control means. As a result, it is possible to promptly notify the abnormality of the fan motor, and it is possible to prompt appropriate and prompt countermeasures.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration of an embodiment of a fan motor control device of the present invention, which is an example applied to control of a fan motor in a bathroom heating dryer.

  The fan motor control device 1 includes a high voltage unit 1a and a low voltage unit 1b. Since the high voltage unit 1a and the low voltage unit 1b are separated from each other by a GND line, the fan motor control device 1 is used to drive the fan motor FM. The PWM signal (control signal) from the control microcomputer 2 as the control means is transmitted to the fan motor control means 3 by the first photocoupler PC1, and the fan motor control means 3 generates from the commercial AC power supply by this PWM signal. The DC 140V power supply is controlled to be turned on / off, and an arbitrary AC voltage is applied to the fan motor FM.

  The fan motor current supplied to the fan motor FM as described above flows through the current detection resistor 4, and the voltage is amplified by the current detection means 5. In order to transmit the voltage amplified by the current detection means 5 from the high voltage unit 1a to the low voltage unit 1b, the ON duty is changed to a pulse waveform, which is transmitted via the second photocoupler PC2, and in the low voltage unit 1b, The signal is sufficiently integrated to provide an AD input to the control microcomputer 2.

  In the nonvolatile RAM area provided in the control microcomputer 2 that comprehensively controls the operation / stop of the fan motor control device 1, a first current value determined in advance as an abnormal fan motor current value exceeding the appropriate range is stored. When the fan motor current value detected by the current detecting means 5 reaches the first current value, it is determined that the fan motor current value is abnormal and the voltage applied to the fan motor FM is reduced to the fan motor control means 3. The control signal is changed. That is, in the present embodiment, each function as the nonvolatile storage means, the abnormality determination means, and the abnormality automaticity control means is realized by the control microcomputer 2 and its control program.

  Note that the control signal (PWM signal) change control by the operation control means at the time of abnormality of the control means (control microcomputer 2) at the time of abnormality determination is performed by lowering the applied voltage to the fan motor FM to bring the fan motor current to an appropriate range. This includes control for returning and continuing the operation of the fan motor FM, control for stopping the fan motor by stopping the output of the control signal to the fan motor control means 3, and the like.

  For example, the control microcomputer 2 that has detected that the fan motor current has reached the first current value lowers the duty ratio of the PWM signal (lowers the pulse width of the PWM signal), and the fan motor control means 3 sends the fan motor FM. If the voltage applied to is reduced and feedback control based on the value detected by the current detection means 5 is performed so that the detected current value by the current detection means 5 is less than the first current value, the fan motor FM is directly applied. The drive control can be continued, and the reliability as the fan motor control device 1 can be improved.

  On the contrary, in order to give priority to safety, the control microcomputer 2 stops the PWM signal and terminates the voltage application by the fan motor control means 3 to completely stop the operation of the fan motor FM in order to give priority to safety. Anyway. Alternatively, the control may be such that the low speed operation is temporarily performed and then the normal operation is restored. That is, how to specifically set the abnormal operation control performed by the abnormal operation control means after the abnormality determination is within the category of design matters.

  Moreover, at the time of abnormal state determination, the abnormality notification information is transmitted from the remote controller 6 to the information notification device 1c, so that the information notification device 1c notifies that an abnormality has occurred in the fan motor FM. The information alarm device 1c is provided at a position that is easily noticeable, such as a bathroom inner wall away from the housing in which the high-voltage unit 1a and the low-voltage unit 1b are stored. In the mode of notification by the information notification device 1c, character information such as “fan motor abnormality” is displayed on the liquid crystal panel, together with visual notification that is easy to call attention such as blinking of a red lamp.

  Note that the configuration of information notification performed by the control microcomputer 2 is not limited to wireless communication using infrared rays or the like, but can also be wired communication in which a cable is laid up to a location where the information notification device is located, and visual notification. However, the present invention is not limited to this, and sound notification by a speaker may be performed, and visual notification and auditory notification may be performed simultaneously. Alternatively, a warning sound may be output from an information notification terminal that can be carried by a person, or the information notification terminal may be vibrated.

  Further, current limiting means 7 comprising a current limiter circuit is provided in the current feedback path to the fan motor control means 3, and when the fan motor current reaches the second voltage value, the current limiting means 7 is activated, and the fan motor The feedback current to the control means 3 is limited to prevent the circuit constituting the fan motor control means from being broken.

  The second current value at which the current limiting means 7 operates is set to a value slightly higher than the first current value used by the control microcomputer 2 for determining abnormality of the fan motor current, and the fan motor current increases slowly. In this case, the fan motor current is decreased by the control of the control microcomputer 2, and if the fan motor current increases rapidly, the second current value is reached before the control microcomputer 2 performs the control. Then, the current limiting means 7 operates to protect the fan motor control means 3, and then the fan motor current is reduced by the control of the control microcomputer 2. These first current value and second current value may be arbitrarily set according to the setting of the safe range and the dangerous range during normal operation of the fan motor FM, and this is also a category of design matters.

It is a schematic block diagram of the fan motor control apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fan motor control apparatus 1a High voltage | pressure part 1b Low voltage | pressure part 1c Information alarm 2 Control microcomputer 3 Fan motor control means 4 Current detection resistance 5 Current detection means 6 Remote control 7 Current limiting means PC1 1st photocoupler PC2 2nd photocoupler

Claims (4)

A control unit that comprehensively controls the driving / stopping of the fan motor, and a voltage based on a control signal from the control unit is applied to the fan motor, and the applied voltage fed back is matched with a voltage based on the control signal. And a fan motor control means for controlling a voltage applied to the fan motor, and a voltage control type fan motor control device comprising:
A current detecting means for detecting a fan motor current supplied to the fan motor;
Control means for receiving the fan motor current value detected by the current detection means,
Nonvolatile storage means for storing a predetermined first current value as an abnormal fan motor current value exceeding an appropriate range;
An abnormality determination means for determining an abnormal state in which the fan motor current value detected by the current detection means has reached the first current value stored in the nonvolatile storage means;
Based on the abnormality determination by the abnormality determination means, an abnormal-time operation control means for changing a control signal to the fan motor control means so as to reduce the voltage applied to the fan motor;
A fan motor control device comprising: A current that operates as hardware when the current value of the fan motor that flows through the fan motor reaches a predetermined second current value that is larger than the first current value, and that limits the feedback current to the fan motor control means. Provide a limiting means,
The fan motor current value has reached the second current value due to a sudden increase in current before the abnormality determination unit of the control unit performs abnormality determination and the control signal to the fan motor control unit is changed by the abnormal operation control unit. 2. The fan motor control device according to claim 1, wherein the feedback current to the fan motor control unit is limited to a second current value or less by the current limiting unit.   The abnormal operation control means of the control means changes the control signal to the fan motor control means so that the fan motor current value detected by the current detection means falls below the first current value. The fan motor control device according to claim 1 or 2, characterized in that 4. The fan motor according to claim 1, further comprising an abnormality notifying unit that notifies an abnormality of the fan motor based on the abnormality determining unit determining an abnormal state. 5. Control device.

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