JPH0263085B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a dual sensor system for controlling a cooling fan of cooling water, which is mainly suitable for motorcycles. (Prior Art) A cooling fan control system as shown in FIG. 1 is known. A cooling fan 12 that cools a radiator 11 for cooling water of the engine is driven by a motor 13. The motor 13 is electrically connected to a battery 14, and a relay 15 is provided in the middle. relay 15
is turned on (connected) by its relay coil 16,
The relay coil 16 is connected to a water temperature sensor 17 that detects the temperature of the cooling water. The water temperature sensor 17 is set to turn on when the temperature reaches a predetermined temperature, and when the water temperature sensor 17 turns on, current flows through the relay coil 16, turning on the relay 15, and the cooling fan 12 is driven by the motor 13. It is becoming more and more common. However, the above configuration has the following problems. That is, if the predetermined temperature is set high, overheating may occur when the engine is stopped immediately after driving. Therefore, if the predetermined temperature is set low, the operating rate of the cooling fan will increase, causing a problem that the battery power will be exhausted during low-speed driving when the engine has low power generation capacity. Therefore, in motorcycles and the like equipped with electric cooling fans, it becomes necessary to increase the power generating capacity of the generator, which inevitably leads to an increase in weight and cost. (Purpose of the invention) By detecting the engine oil temperature, the operating temperature of the cooling fan can be automatically changed according to the engine condition, thereby suppressing unnecessary fan operation and reducing battery load. do. Furthermore, this eliminates the need to increase the size of the generator, thereby reducing weight and cost. (Structure of the Invention) The present invention includes a battery, a high water temperature sensor that detects a temperature higher than a high set temperature of engine cooling water,
In a dual sensor system for cooling fan control equipped with a low water temperature sensor that detects a temperature higher than a low set temperature, a first circuit, a second circuit, and a third circuit are connected between the battery and the ground. The first circuit includes a normally open fan switch whose one end is connected to the battery, and a cooling fan drive motor whose one end is connected to the other end of the fan switch, The circuit includes a switch control mechanism whose one end is connected to the battery to control opening and closing of the fan switch, a sensor switch whose other end is connected to a connection terminal, and a sensor switch which controls the height of the sensor switch. a fourth circuit that connects a fixed contact for a water temperature sensor and the high water temperature sensor; a fifth circuit that connects a fixed contact for a low water temperature sensor of the sensor switch and the low water temperature sensor; The circuit of
An ignition switch, one end of which is connected to the battery, and one end of which is connected to the other end of the ignition switch, connects the connection terminal of the sensor switch to the fixed contact for the high water temperature sensor and the fixed contact for the low water temperature sensor. The ignition switch is equipped with a switch switching mechanism that is selectively connected to one of the contacts, and an engine temperature sensor that has one end connected to the other end of the switch switching mechanism. When closed, the switch switching mechanism connects the connection terminal of the sensor switch to the high water temperature sensor fixed contact,
When the ignition switch is open or when the engine temperature sensor detects a temperature higher than the set temperature in the hydraulic oil of the engine, the switch switching mechanism connects the connection terminal of the sensor switch to the low water temperature sensor. This is a dual sensor system for cooling fan control that is set to be connected to a fixed contact. (Example) In FIG. 2, a cooling fan 21 for cooling a radiator 20 is fixed to the output shaft of a motor 22. The motor 22 is electrically connected to the battery 24 via a relay 25 (an example of a fan switch) of a first circuit 23 . first circuit 2
3 is a series circuit formed between the battery 24 and the ground 19, one end of the relay 25 is connected to the other end of the battery 24, and the other end of the relay 25 is connected to one end of the motor 22. . relay 25
is turned ON (connected) and OFF (disconnected) by its relay coil 26 (an example of a switch control mechanism). The relay coil 26 is provided in the middle of a second circuit 27 provided between the battery 24 and the ground 19.
One end of the relay coil 26 is branched from between the battery 24 and the relay 25, and the other end of the relay coil 26 is connected to the relay 28.
(an example of a sensor switch). The relay 28 is a relay coil 3 of a third circuit 35 provided between the battery 24 and the ground 19.
6 (an example of a switch switching mechanism), the connection terminal A is switched to be connected to either the fixed contact B for the high water temperature sensor or the fixed contact C for the low water temperature sensor. The fixed contact B for the high water temperature sensor is connected to the fourth circuit 2.
9 to the high water temperature sensor 31. Further, the low water temperature sensor fixed contact C is connected to the low water temperature sensor 32 by a fifth circuit 30. When the relay coil 36 is energized, the relay 28 connects the connection terminal A to the fixed contact B for the high water temperature sensor, and connects the second circuit 27 and the fourth circuit 2.
9 is switched to the state where it is connected, and the relay coil 36
When the current is turned off, the connection terminal A is automatically connected to the fixed contact C for the low water temperature sensor, and the second circuit 2 is connected.
7 and the fifth circuit 30 are connected again. The high water temperature sensor 31 and the low water temperature sensor 32 are in direct contact with cooling water in a water jacket of an engine (not shown), and are capable of detecting the temperature of the cooling water. Here, the high water temperature sensor 31 is set to turn on when the water temperature is 110 degrees or higher (an example of a high set temperature), and the low water temperature sensor 32 is set to turn on when the water temperature is 97 degrees (an example of a low set temperature).
It is set to turn ON if the above is reached. The third circuit 35 has one end connected to the battery 24 and the other end connected to the ground 19 as described above. Between battery 24 and earth 19,
Relay coil 36 of relay 28 is connected. One end of the relay coil 36 is connected to the other end of an ignition switch 37, and the other end of the relay coil 36 is connected to an oil temperature sensor 39 (an example of an engine temperature sensor). Further, a circuit 40 branching from the third circuit 35 between the relay coil 36 and the ignition switch 37 is connected to an ignition coil (not shown). The oil temperature sensor 39 is designed to detect the oil temperature by directly contacting the engine's hydraulic oil.
It is set to turn off when the temperature exceeds 120 degrees. Next, the operation will be explained. First, the ignition switch 37 is turned on to start the engine, and then, for example, in the case of a motorcycle, the vehicle enters a running state. <Driving at low speed> In this case, the engine speed is low and the temperature of the hydraulic oil is low (for example, less than 120 degrees). Therefore, the oil temperature sensor 39 is in the ON state, the relay coil 36 is energized, and the connection terminal A of the relay 28 is connected to the fixed contact B for the high water temperature sensor.
is in a state where the second circuit 27 and the fourth circuit 29 are connected. As a result, the high water temperature sensor 31 whose set temperature is 110 degrees acts on the relay coil 26. When the water temperature rises to 110 degrees or more, the high water temperature sensor 31, which was previously in the OFF state, turns on.
Then, the relay coil 26 is energized. As a result, the relay 25 is turned ON, and the battery 2 is discharged from the motor 22.
4 is connected and the cooling fan 21 rotates, thereby cooling the cooling water in the radiator 20. When the cooling water is cooled down to less than 110 degrees, the high water temperature sensor 31 is turned OFF, power to the relay coil 26 is stopped, and the relay 25 is turned off.
Turn off. If the vehicle continues to travel at low speed, automatic control is repeated with the set temperature high, so the operating rate of the cooling fan 21 decreases and no more power is consumed than necessary. <Immediately after driving at low speed> When the ignition switch 37 is turned OFF to stop the engine, the power supply to the relay coil 36 is stopped and the connection terminal A of the relay 28 is connected to the fixed contact C for the low water temperature sensor, so the relay 28 is switched to connect the second circuit 27 and the fifth circuit 30. As a result, relay coil 26
In contrast, the low water temperature sensor 32 whose set temperature is 97 degrees operates. Therefore, even after the engine is stopped, as long as the temperature of the cooling water is 97 degrees or higher, the low water temperature sensor 32 is turned on, turning on the relay 25, and turning on the cooling fan 21.
continues to rotate to reliably cool the cooling water in the radiator 20. When the temperature of the cooling water becomes less than 97 degrees, the low water temperature sensor 32 turns OFF and the cooling fan 21
stops. <While driving at high speed> The engine speed is high and the temperature of the hydraulic oil is high (for example, over 120 degrees). Therefore, oil temperature sensor 3
9 is in the OFF state, and the relay coil 36 is no longer energized. Therefore, connection terminal A of relay 28
is connected to the fixed contact C for the low water temperature sensor, so the relay 28 is connected to the second circuit 27 and the fifth circuit 3.
0 is connected. As a result, the low water temperature sensor 32 whose set temperature is 97 degrees acts on the relay coil 26. When the water temperature rises and exceeds 97 degrees,
Low water temperature sensor 32 that had been in the OFF state until then
is turned on, and the relay coil 26 is energized. This turns on the relay 25, connects the battery 24 to the motor 22, and rotates the cooling fan 21, thereby cooling the cooling water in the radiator 20. If the cooling water cools down to less than 97 degrees,
The low water temperature sensor 32 is turned off, power to the relay coil 26 is stopped, and the relay 25 is turned off.
Turn off. If the vehicle continues to drive at high speeds, automatic control is repeated at a low set temperature, ensuring that the cooling water is maintained at a relatively low temperature at all times. <Immediately after driving at high speed> When the ignition switch 37 is turned off to stop the engine, the power supply to the relay coil 36 is stopped, but in this case, the oil temperature is 120°C from the beginning.
℃ or higher, the oil temperature sensor 39 is activated from the beginning.
It is OFF, and there is no change in the state of relay 28.
Therefore, even after the engine has stopped, while the coolant temperature is 97 degrees or higher, the low water temperature sensor 32 is in the ON state and the relay 25 is turned ON, and the cooling fan 21 continues to rotate to ensure that the coolant in the radiator 20 is flowing. Cool to When the temperature of the cooling water becomes less than 97 degrees, the low water temperature sensor 32 is turned off and the cooling fan 21 is stopped. The above operation is shown in the table below.

[Table] (Effects of the invention) (a) Since the operating temperature setting of the cooling fan can be automatically changed according to the engine condition, unnecessary fan operation can be suppressed and the load on the battery can be reduced. . (b) It also eliminates the need for larger generators;
It becomes possible to reduce weight and cost. (c) Connect the first circuit and the second circuit between the battery and ground.
The first circuit includes a normally open fan switch whose one end is connected to the battery, and a cooling fan drive circuit whose one end is connected to the other end of the fan switch. The second circuit includes a switch control mechanism whose one end is connected to the battery to control opening and closing of the fan switch, and a sensor switch whose connection terminal is connected to the other end of the switch control mechanism. , a fourth circuit that connects the high water temperature sensor fixed contact of the sensor switch and the high water temperature sensor, and a fifth circuit that connects the low water temperature sensor fixed contact of the sensor switch and the low water temperature sensor. The third circuit includes an ignition switch, one end of which is connected to the battery, and one end of which is connected to the other end of the ignition switch, and the third circuit connects the connection terminal of the sensor switch to the high water temperature sensor. A switch switching mechanism selectively connected to either the fixed contact or the fixed contact for the low water temperature sensor, and an engine temperature sensor having one end connected to the other end of the switch switching mechanism, When the ignition switch is closed, the switch switching mechanism connects the connection terminal of the sensor switch to the high water temperature sensor fixed contact, and when the ignition switch is open, the switch switching mechanism connects the connection terminal of the sensor switch to the high water temperature sensor fixed contact. The switch switching mechanism is set to connect the connection terminal of the sensor switch to the fixed contact for the low water temperature sensor when the engine temperature sensor detects a temperature higher than the set temperature in the engine hydraulic oil. Even if the ignition switch is shut off immediately after driving at low or high speeds, the cooling fan continues to rotate as long as the engine is at a high temperature, allowing the cooling water in the radiator to be reliably cooled. Therefore, the cooling fan can be operated as and when required. (d) Since an engine temperature sensor is used to detect the oil temperature of the engine, it is possible to directly and reliably detect the heat load state of the engine. In addition, since the temperature sensor can be constructed with a simple electric circuit, it can be provided with an inexpensive structure.
Moreover, reliability is also increased. Also, since it uses an engine temperature sensor,
For example, even if the temperature of various parts of the engine increases while driving at low speeds, such as immediately after driving at high speeds or when driving on a hill, the sensor can be switched to a low water temperature sensor without depending on the vehicle speed, and a sufficient cooling effect can be obtained. . Therefore, from this point of view, the cooling fan can be operated as and when required, and the engine can be cooled without waste. (Another Embodiment) (a) The electric circuit is not limited to the above configuration, and may be configured using, for example, a thyristor, or may be configured using a logic circuit such as a NAND circuit. (b) When using an oil temperature sensor 39 that turns on at 120 degrees or higher, the switching direction of the relay 28 may be reversed. (c) The engine temperature sensor may be, for example, a thermistor embedded in the cylinder block. (d) High water temperature sensor 31 and low water temperature sensor 32
For example, it may be configured to detect the wall temperature of a water jacket. (e) Of course, the high temperature setting is not limited to 110 degrees, and the low temperature setting is not limited to 97 degrees, and may be set arbitrarily as appropriate.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram of a conventional cooling fan control system, and FIG. 2 is a layout diagram of a dual sensor system for cooling fan control according to the present invention. 19...Earth, 21...Cooling fan, 22
... Cooling fan drive motor, 23 ... First circuit, 24 ... Battery, 25 ... Relay (an example of a fan switch), 26 ... Relay coil (an example of a switch control mechanism), 27 ... Second circuit, 28... Relay (an example of a sensor switch), A... Connection terminal, B... Fixed contact for high water temperature sensor, C... Fixed contact for low water temperature sensor, 2
9...Fourth circuit, 30...Fifth circuit, 31...
...High water temperature sensor, 32...Low water temperature sensor, 3
5...Third circuit, 36...Relay coil (an example of a switch switching mechanism), 37...Ignition switch, 39...Oil temperature sensor (an example of an engine temperature sensor).

Claims (1)

[Claims] 1. In a dual sensor system for cooling fan control that includes a battery, a high water temperature sensor that detects a temperature of the engine coolant that is higher than a high set temperature, and a low water temperature sensor that detects a temperature that is higher than a low set temperature, the battery and the A first circuit, a second circuit, and a third circuit are provided between the ground and the first circuit, and the first circuit includes a normally open fan switch whose one end is connected to the battery, and a fan switch. a cooling fan drive motor, one end of which is connected to the other end; the second circuit includes a switch control mechanism, one end of which is connected to the battery, that controls opening and closing of the fan switch; A sensor switch to which a connection terminal is connected to the other end of the mechanism, a fourth circuit connecting the high water temperature sensor fixed contact of the sensor switch to the high water temperature sensor, and a low water temperature sensor fixed contact of the sensor switch. a fifth circuit connecting the contact and the low water temperature sensor; the third circuit includes an ignition switch having one end connected to the battery;
a switch switching mechanism having one end connected to the other end of the ignition switch and selectively connecting the connection terminal of the sensor switch to either the high water temperature sensor fixed contact or the low water temperature sensor fixed contact; and an engine temperature sensor whose one end is connected to the other end of the switch switching mechanism, and when the ignition switch is closed, the switch switching mechanism controls the sensor switch. The above connection terminal is connected to the fixed contact for the high water temperature sensor, and when the above ignition switch is open or the above engine temperature sensor detects a temperature higher than the set temperature in the engine hydraulic oil, the above switch switching mechanism is activated. A dual sensor system for controlling a cooling fan, characterized in that the connection terminal of the sensor switch is connected to the fixed contact for the low water temperature sensor.