JP2003023792A - Fan motor for blowing provided with self-diagnostic function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fan motor providing self-diagnostic function for estimating operating life time, after the fan motor for blowing is installed and stopping the operation, before the motor is stopped due to generation of fault. SOLUTION: A current waveform of a stator coil is detected, and this is then compared with a stationary waveform stored in a storage device. If a change in the waveform exceeding the reference value is detected, a signal is sent to a power feeding control circuit to stop the operation of fan motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower fan motor, and more particularly, to a self-diagnosis function of comparing a current value during operation by storing a current value of a winding in a microcomputer and a memory element provided in the microcomputer. Regarding what to prepare.

[0002]

2. Description of the Related Art Conventionally, a stator having a stator winding, a rotor rotatably rotatably supported so as to face the stator winding via a gap, and having a permanent magnet and a fan, and the rotor. The rotor has a Hall element for detecting the magnetic pole position of the child permanent magnet, and an energization control circuit controlled by the output voltage of the Hall element, and the rotor is energized by the energization control circuit. The fan motor for blower, which is configured to obtain rotation in a predetermined direction and also includes a microcomputer for controlling the operation, has been put to practical use. The blower fan motor is an important component, for example, provided in the housing of the electronic device and releasing heat inside the housing to ensure safe operation of the electronic device. It is no exaggeration to say that the life of the fan motor controls the life of the electronic device.

[0003]

However, it is difficult to predict the life of the blower fan motor, and at present, the results of continuous operation tests on many samples by the manufacturer indicate that
You are just getting the estimated life. Therefore, it is equipped with a self-diagnosis function that can grasp the change of the winding current waveform with the passage of time from the continuous operation test data and judge that the life has reached when the current waveform changes by a predetermined amount from the reference value in the mounted state. The advent of fan motors for blowing air was desired.

[0004]

A blower fan motor that uses a practical brushless DC motor as a drive source is in a continuous rotation state while the electronic device is powered on because of its mounting. The main factor related to the life is the bearing, and the deterioration of the bearing appears in the change in the winding current.

A blower fan motor having a self-diagnosis function according to the present invention includes a stator having a stator winding, a rotor rotatably supported so as to face the stator winding through a gap, and a permanent magnet. And a fan, a hall element for detecting a magnetic pole position of the rotor permanent magnet, and an energization control circuit controlled by obtaining an output voltage of the hall element. A fan motor for blower configured to obtain rotation of a rotor in a predetermined direction by energizing a stator winding, which also includes a microcomputer for controlling the operation of the fan motor. ,
A current signal processing circuit, a storage element for previously processing and storing a steady-state current value, and a comparison circuit for comparing the steady-state current value stored in the storage element with the operating current value When the abnormal current value is detected by the occasional comparison in the comparison circuit, the fan motor is stopped. The current signal processing circuit generates a zero timing signal from the output voltage of the Hall element, a time axis signal generation circuit, a sampling circuit, and an A / D that converts an instantaneous value corresponding to the time axis into a digital value. A conversion circuit is provided, and the current signal processing circuit and the comparison circuit are configured to operate according to a program written in an attached microcomputer.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings.

[0007]

1 is a block diagram of a control circuit used in a fan motor for blown air according to the present invention, in which 1 is a Hall element,
2 is a microcomputer, 3 is an energization control circuit, 4 is a current detection circuit,
Reference numeral 5 is a stator winding, and 6 is a storage element. The Hall element 1 detects the magnetic pole position of the permanent magnet of the rotor and sends it to the energization control signal generator 2-1 of the microcomputer 2, and sends the signal of the energization control signal generator 2-1 to the energization control circuit 3. The output of the energization control circuit 3 is sent to the stator winding 5 via the current detection circuit 4, and the current controlled by the output of the Hall element 1 flows through the stator winding 5 to rotate the rotor and operate as a fan motor. To do.

The current in the stator winding 5 differs depending on the individual, and it is difficult to judge the current change during long-term operation by comparing the effective values thereof. Therefore, the current waveform is detected, and the change in the steady state is detected. By comparing with the value, it is easy to determine the current change.

The current detection circuit 4 is composed of a resistance element, and the voltage drop thereof is sent as a current signal to the current signal processing circuit 2-2 of the microcomputer 2.

The structure of the current signal processing circuit 2-2 is shown in FIG. In FIG. 2, reference numeral 10 is a circuit for receiving the output voltage of the Hall element and a zero timing generation circuit, 11 is a current detection circuit, and 12 is a current detection circuit.
Is a sampling circuit, 13 is a sampling timing signal generation circuit, 14 is an A / D conversion circuit, 15 is a signal comparison circuit, and 16 is a storage device.

The operation of the current signal processing circuit 2-2 shown in FIG.
It is captured in 2, and detected by the sampling timing signal 13 and sent to the A / D conversion circuit 14 to be converted into a sequence of digital signals corresponding to the sampling timing. The zero timing of sampling is based on the zero timing signal 10.

The digital value of the current value sent from the A / D conversion circuit 14, the digital value of the storage device 16 and the zero timing signal 10 are input to the comparison circuit 15, and the A
The digital value of the current value sent from the A / D conversion circuit 14 and the digital value of the storage device 16 are compared based on the zero timing signal 10, and the detected current value and the storage value of the storage device 16 are stored. The normal value is compared, and when it exceeds a predetermined reference value, the comparison circuit 15 sends an energization stop signal to the energization control circuit to stop the fan motor.

Further, the current signal processing circuit shown in FIG. 2 is adapted to operate according to a preset control program stored in the microcomputer 2. The operation of the control program will be described with reference to the flowchart shown in FIG. Based on the zero timing of the timing pulse signal 10 synchronized with the signal of the Hall element 1, the generated signal of the sampling signal generation circuit 13 and the current value fetched from the current detection circuit 11 are input to the sampling circuit 12, and the current The value is sampled with reference to the zero timing of the timing pulse signal 10, sent to the A / D conversion circuit 14 to be converted into digital data, and sent to the comparison circuit 15, while the reference value of the current stored in the storage element 16 Is sent to the comparison circuit 15 in synchronization with the signal of the sampling signal generation circuit 13,
The current value is compared with the digital value of the current, and the current value is compared with the reference value. When the reference value of the life judgment set in the comparison circuit 15 is exceeded, the comparison circuit 15 causes the energization control circuit of the microcomputer 2 A command to stop energization is sent to the fan motor to stop it.

Since there are individual differences in the current waveform of the stator winding, the reference value for life judgment is set with a certain width.

[0015]

Since the fan motor for blower having the self-diagnosis function according to the present invention is configured as described above, the current waveform is compared with the waveform held in the storage device, and the current value exceeds the predetermined reference value. When the change occurs, the fan motor can be stopped, so that the fan motor can be replaced before the life of the fan motor expires, and the life of the mounted electronic device can be extended.

[Brief description of drawings]

FIG. 1 is a block diagram of a fan motor control circuit according to the present invention.

FIG. 2 is a block diagram of a current signal processing circuit of a fan motor according to the present invention.

FIG. 3 is a flow chart showing processing in the microcomputer of the current signal processing circuit of the fan motor according to the present invention.

[Explanation of symbols]

1 Hall element 2 microcomputer 2-1 Microcomputer energization signal generation circuit 2-2 Microcomputer current signal processing circuit 3 energization control circuit 4 Current detection circuit 5 Stator winding 6 storage device 10 Zero timing signal generation circuit 11 Signal converted from current to voltage 12 Sampling circuit 13 Sampling timing signal generation circuit 14 A / D conversion circuit 15 Comparison circuit 16 storage

Claims (3)

[Claims] 1. A stator having a stator winding, a rotor rotatably rotatably supported so as to face the stator winding via a gap, and having a permanent magnet and a fan, and the rotor permanent magnet. A Hall element for detecting the magnetic pole position of the rotor, and an energization control circuit that is controlled by obtaining the output voltage of the Hall element, and by energizing the stator winding by the energization control circuit, A blower fan motor configured to obtain rotation in a predetermined direction, which also includes a microcomputer for controlling the operation, and a winding current detection circuit,
A current signal processing circuit, a storage element for previously processing and storing a steady-state current value, and a comparison circuit for comparing the steady-state current value stored in the storage element with the operating current value A fan motor for blower having a self-diagnosis function, which is configured to stop the fan motor when an abnormal current value is detected by an occasional comparison in the comparison circuit. 2. The current signal processing circuit receives an output voltage of a hall element, generates a zero timing circuit, a time axis signal generation circuit, a sampling circuit, and converts an instantaneous value corresponding to the time axis into a digital value. A storage element having a / D conversion circuit and processing and storing a steady-state current value, and a comparison circuit for comparing the steady-state current value stored in the storage element with the operating current value. The comparison circuit is also configured to stop the fan motor when an abnormal current value is detected by comparing waveforms at any time with the zero timing as a base point.
An air blower fan motor having the self-diagnosis function described in 1. 3. The current signal processing circuit and the comparison circuit are configured to operate according to a program written in a microcomputer provided side by side.
Alternatively, a blower fan motor having the self-diagnosis function described in 2.