JPH025892B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a radiator cooling fan motor monitoring drive device for a front-wheel drive passenger car.

<Conventional technology and problems> Due to the placement of the engine in FF passenger cars,
The radiator cooling fan (hereinafter referred to as fan) cannot be mechanically driven directly from the engine, so it is electrically driven by a motor. However, if there was a malfunction in the motor's electrical circuit, such as a disconnected connector, a blown fuse, or poor contact, the fan would not operate and the engine would overheat.

In order to solve these problems, a check circuit disclosed in Japanese Utility Model Application Laid-Open No. 55-161019 has been known. However, in the technology disclosed in Utility Model Application Publication No. 55-161019, the alarm is generated based on the logic between the water temperature switch and the actual rotation of the fan motor, so in order to detect the circuit of the fan motor, a detection brush is generally installed separately on the fan motor. It is necessary to install a fan motor, and the fan motor has to be made into a special one, which makes it expensive.
It would also be difficult to improve existing fan motor circuits. In addition, in order to check the fan motor, the fan motor is forcibly operated for a predetermined period of time when the engine is started, so since it is normally normal, there may be an increase in the noise caused by the fan or the power supply voltage is not supplied to the fan motor. It seems that it is difficult to avoid a decrease in engine startability due to this, and power consumption due to the same reason.

Furthermore, even if an abnormality in the fan motor circuit is discovered early, it may not be possible to repair it immediately.
It is inconvenient for the driver to be unable to use the vehicle immediately.

The present invention has been made in response to the above-mentioned conventional technical situation, and can be retrofitted (retrofitted) to an existing fan motor circuit without actually operating the fan motor or making the fan motor special. (improvement), and it is possible to detect an abnormality in the electric circuit of the fan motor when starting the engine, and in the event of an abnormality, the water temperature in the radiator can be detected and the fan motor can be temporarily driven by a separate system. The purpose of the present invention is to provide a fan motor monitoring and driving device that can be used.

<Means for Solving the Problems> The configuration of the fan motor monitoring drive device according to the present invention that achieves the above object includes an ignition switch between the power supply and ground, and a water temperature switch that opens and closes depending on the water temperature of the radiator. and a fan motor operated by the water temperature switch are connected in series, and the fan motor control circuit is connected to the power supply side terminal of the water temperature switch, and the water temperature is determined from the power supply by detecting the voltage of the power supply side terminal. A short-circuit/open detection circuit detects and outputs whether the circuit up to the power supply side terminal of the switch is short-circuited or open, and is connected to the fan motor side terminal of the water temperature switch to detect the voltage of the fan motor side terminal. As a result, there is an open detection circuit that detects whether the circuit from the fan motor side terminal of the water temperature switch to the ground is open and outputs an output, and an open detection circuit that is activated when the ignition switch is on, and detects the short circuit/open circuit. A warning circuit that outputs an output when at least one of the circuit and the open circuit detects an output, and an output signal of the warning circuit is output and it is detected that the water temperature of the radiator exceeds a predetermined temperature. a fan motor drive circuit that drives the fan motor in a separate system from the water temperature switch;
It is characterized by having the following.

<Example> An example of a fan motor monitoring and driving device according to the present invention will be described with reference to the drawings. The figure is a circuit configuration diagram of an embodiment of the present invention.

As shown in the figure, one end of the fan motor 1 is grounded, and the other end is connected to a water temperature switch 2, a fuse 3,
It is connected to the power supply AM via IG switch (ignition switch) 4. The water temperature switch 2 is turned on and off by driving a movable piece 2a whose power supply side terminal X and fan motor side terminal Y are controlled by the water temperature of the radiator. A short-circuit/open detection circuit 5 is connected to the power supply terminal X of the water temperature switch 2 and detects the short-circuit/open state of the X terminal.
An open detection circuit 6 for detecting the open state of the Y terminal is connected to the fan motor side terminal Y. Further, the respective outputs of the short/open detection circuit 5 and the open detection circuit 6 are input to an OR circuit 7, and the output of the OR circuit 7 is input to a set terminal of a flip-flop circuit 8. Q of flip-flop circuit 8
The terminal is connected to the warning lamp 1 via the inverter 9.
0, and the other end of the warning lamp 10 is connected to a power source AM. Warning circuit 18 includes an OR circuit 7 and a flip-flop circuit 8. In addition, the terminal voltage of the sender resistor 11 that drives the water temperature switch 2 that detects the water temperature of the engine radiator, and a specific reference voltage power source 12 that detects the terminal voltage of the sender resistor when the water temperature switch is activated are input. The output of the comparator 13 is input to the NAND circuit 14 along with the output of the Q terminal of the flip-flop circuit 8, and the drive coil 15 of the backup relay 16 is connected to the output of the NAND circuit 14.
It is connected between AM and AM. The fan motor drive circuit 19 includes a comparator 13 and a NAND circuit 14. Furthermore, the drive coil 1 of the backup relay 16
The circuit contacts 16a and 16b which are closed by the bias of 5 are
It is loaded between the IG switch 4 and the fan motor 1 via a fuse 17. According to the fan motor monitoring and driving device according to the present invention, while the IG switch 4 is turned on and the water temperature switch 2 is activated,
If there is an abnormality in the electric circuit of the fan motor, it will be detected and the warning lamp 10 will be lit to notify the driver.In addition, as a backup function, the water temperature switch 2 will be activated along with this abnormality detection signal.
Monitor the voltage of the resistor of the sender and switch the water temperature switch 2.
detects a voltage indicating the operating temperature, energizes the drive coil 15 of the back-up relay 16 based on the two detection signals, connects the fan motor 1 directly to a power source in a separate system, and drives the fan motor 1. death,
This provides a complete fail-safe function that protects the fan motor 1 from not operating due to an abnormality in the electric circuit of the fan motor 1.

In the figure, if there is an abnormality in the circuit between the X terminal of water temperature switch 2 and the power supply, such as a blown fuse or a disconnection of the circuit, or a circuit abnormality such as the X terminal is short-circuited or disconnected, the connection to the The short circuit/open detection circuit 5 detects these abnormalities and outputs “1”.
Input to OR circuit 7. In addition, the open detector 6 connected to the Y terminal is in a state where the Y terminal is grounded by the fan motor 1 or when the water temperature switch 2 is turned on.
If the terminal reaches the power supply potential, it is normal and is not detected, but if the Y terminal is open, the circuit is abnormal and this state is detected. When the Y terminal open circuit detection circuit 6 detects an open circuit, the detection output “1” is input to the OR circuit 7. If the OR circuit 7 is an abnormality detection input, it sets the flip-flop circuit 8, and an output signal appears at the Q terminal, which is inverted by the inverter 9. The output of the inverter 9 becomes 0 potential, and the power supply voltage acts on the warning lamp 10. , lights up to notify you that there is an abnormality in the fan motor circuit. The warning lamp 10 is self-maintained by a flip-flop circuit 8, and the IG switch 4 is connected to the reset terminal.
The OFF signal releases the self-holding state and turns off the light.
Merely detecting an abnormality and turning on the warning lamp does not resolve the abnormality and is insufficient, so the sensor's resistance (R) 11, which detects the water temperature of the engine radiator and drives the water temperature switch 2, Input the terminal voltage of water temperature switch 2.
NAND circuit 1
4, energizes the drive coil 15 of the backup relay 16, and connects the fuse 17 to the IG switch 4.
Backup relay 16 connected via
and the other circuit contact 1 of the back-up relay 16 connected to the fan motor 1.
By short-circuiting 6b with a movable piece and applying a power supply voltage to the fan motor 1 to drive the fan motor 1, it is possible to not only detect a circuit abnormality in the fan motor 1, but also to detect a circuit abnormality in the fan motor 1 using a separate circuit. The motor 1 can be operated to prevent the engine radiator from overheating.

<Effects of the Invention> According to the fan motor monitoring and driving device according to the present invention, the circuit of the fan motor is maintained even after the IG switch is turned on until the water temperature switch is activated, that is, even before the fan motor actually operates at the time of engine start. If there is an abnormality, it will be detected and the driver will be notified of the abnormality in the radiator fan motor circuit.Until the problem is repaired, a separate fan motor drive circuit will automatically shut down the fan if the radiator water temperature exceeds a predetermined temperature. The motor can be activated to prevent the engine from overheating.

As a result, the driver not only knows if there is an abnormality in the fan motor circuit, but also can continue to use the vehicle as usual while the abnormal circuit is being repaired. In this case, the separate fan motor drive circuit operates only when the normal fan motor circuit becomes abnormal, so the durability can be set lower than the normal fan motor circuit, and it is therefore cheaper. In addition, it is possible to prevent engine overheating without increasing abnormalities such as circuit abnormalities causing the fan motor to stop rotating and overcooling the engine. Summer.

Furthermore, since actual operation of the fan motor is not required to detect an abnormality in the fan motor circuit, there is no noise caused by the fan, engine startability does not deteriorate, and there is no wasteful consumption of electric power. Furthermore, since it is determined whether or not there is an abnormality based on the voltage detection of the power supply side terminal of the water temperature switch and the fan motor side terminal, there is no need for a special fan motor, and the fan motor drive of the present invention can be added to the existing fan motor circuit. A monitoring device can be easily attached.

[Brief explanation of drawings]

The figure is a circuit configuration diagram of an embodiment of a fan motor monitoring and driving device according to the present invention. In the drawing, 1 is the fan motor, 2 is the water temperature switch, 3 is the fuse, 4 is the IG switch, 5 is the short circuit/open detection circuit, 6 is the open detection circuit, and 7 is the OR
circuit, 8 is a flip-flop circuit, 9 is an inverter, 10 is a warning lamp, 11 is a transmitter resistor, 12 is a reference voltage power supply, 13 is a comparator, 14 is a NAND circuit, 15 is a backup relay coil, 16 is a backup relay relay, 16
a, 16b are the circuit contacts of the backup relay, 1
7 is a fuse, 18 is a warning circuit, and 19 is a fan motor drive circuit.

Claims (1)

[Scope of Claims] 1. A fan motor in which an ignition switch, a water temperature switch that opens and closes depending on the water temperature of a radiator, and a fan motor operated by the water temperature switch are connected in series between a power source and ground. The control circuit is connected to the power supply terminal of the water temperature switch, and by detecting the voltage of the power supply terminal, detects whether the circuit from the power supply to the power supply terminal of the water temperature switch is short-circuited or open, and outputs the result. A short circuit/open detection circuit is connected to the fan motor side terminal of the water temperature switch, and by detecting the voltage of the fan motor side terminal, it is possible to detect whether the circuit from the fan motor side terminal of the water temperature switch to ground is in an open state. an open detection circuit that detects and outputs an open circuit; and an open detection circuit that is activated when the ignition switch is in an on state, and generates a warning when an output is received from at least one of the short circuit/open detection circuit and the open detection circuit. and a fan motor drive circuit that drives the fan motor in a separate system from the water temperature switch when the output signal of the warning circuit is output and it is detected that the water temperature of the radiator exceeds a predetermined temperature. A fan motor monitoring drive device comprising: