JPH0598963A - Cooling fan control device - Google Patents

Abstract

PURPOSE:To minutely determine driving modes of a radiator fan and a condenser fan by combining conditions of a water temperature detected by means of a water temperature sensor and a vehicle speed detected by means of a vehicle speed sensor. CONSTITUTION:Detection values of a water temperature sensor 3, a vehicle speed sensor 22, and the like are input into an engine ECU 21. Not only a water temperature, vehicle speed, but also an A/C operation condition is judged by the engine ECU, and an optimum driving mode is determined and output according to the operation condition of the vehicle, while selecting among OFF, LO(LOW), HI(HIGH) drivings. In respect to output modes of a radiator fan 4 and a condenser fan 5, a common signal is output in the HI and LO drivings, so that a required volume of the engine ECU is saved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a cooling fan provided in a cooling system of an automobile engine and its related equipment, and more specifically, a drive mode depending on a combination condition of vehicle speed and cooling water temperature. The present invention relates to a switching cooling fan control device.

[0002]

2. Description of the Related Art As a cooling system for automobile engines,
The forced circulation water cooling type with a radiator is generally adopted. This radiator is equipped with an electric radiator fan that turns on and off depending on the temperature of the cooling water.
Alternatively, it is controlled so as to switch the drive mode of OFF-LO (LOW) drive-HI (HIGH) drive. In addition, an air conditioner (hereinafter referred to as A / C) is generally installed in an automobile in recent years. In such an A / C installed vehicle, improvement of cooling performance and fan noise during idling,
Radiator fan and A /
The condenser fan for C was drive-controlled as follows.

FIG. 4 is a system diagram showing a conventional cooling fan controller, which is an engine EC for controlling the operation of the engine 1.
A water temperature sensor 3 that detects the water temperature of the cooling water is connected to U2. The water temperature sensor 3 outputs a voltage according to the water temperature, and the engine ECU 2 receiving the output signal from the water temperature sensor 3 determines the warm-up state of the engine 1,
Implement various engine controls.

Further, the radiator fan 4 for cooling the radiator, the condenser fan 5 for cooling the condenser of the A / C and the A / C compressor 6 respectively have a switch 7,
It is connected to the power source 10 via 8 and 9. The switch 7 for turning on / off the radiator fan 4 and the switch 8 for turning on / off the condenser fan 5 are both water temperature switches which are turned on when the temperature of the cooling water becomes a high temperature of a predetermined value or more, and By driving the cooling fan when the water temperature is high, the radiator and the condenser are forcibly cooled to improve the capacity. On the other hand, the switch 9 provided in the circuit of the A / C compressor 6 turns on when the temperature of the cooling water becomes higher than a predetermined value.
It is a water temperature switch that serves as FF and stops the operation of the A / C compressor, and reduces the load on the engine 1 to reduce the load on the radiator as much as possible when the cooling water is at a high temperature. The A / C compressor 6 in the normal state is drive-controlled by an A / C switch (not shown) connected to the engine ECU 2.

The switch 11 connected in parallel with the switch 8 is a pressure switch which is turned on to drive the condenser fan 5 when the amount of the A / C refrigerant is small.

[0006]

According to the conventional cooling fan control device described above, a total of three water temperature switches, one for the radiator fan, one for the condenser fan, and one for the A / C compressor, are required. However, since it is controlled only by the temperature of the cooling water, it is difficult to perform detailed control according to the operating conditions such as vehicle speed. Therefore, in an operating condition in which the cooling fan does not need to be driven, driving the cooling fan consumes unnecessary power. The alternator that supplies this electric power consumes part of the engine output and is driven, which is disadvantageous in improving fuel efficiency and drivability. In addition, the unnecessary operation of the cooling fan is also inconvenient from the viewpoint of noise reduction.

Therefore, an object of the present invention is to switch the drive mode of the cooling fan in accordance with the combination condition of the coolant temperature and the vehicle speed, thereby enabling fine drive control at low cost.

[0008]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and is driven by an electric motor in a control device for a vehicle cooling fan which is driven by using a part of an engine output of a vehicle as a drive source. A cooling fan, a vehicle speed sensor for detecting the traveling speed of the host vehicle, a water temperature sensor for detecting the water temperature of the engine cooling water, and the driving of the cooling fan according to a combination of the vehicle speed and the water temperature detected by the vehicle speed sensor and the water temperature sensor. A cooling fan control device comprising a controller that determines a mode.

[0009]

According to the above-described means, the controller determines the drive mode of the cooling fan according to the combination condition of the conventional cooling water temperature plus the vehicle speed, so that fine drive control can be performed in consideration of the operating condition. Moreover, since the water temperature sensor can continuously detect the water temperature by the voltage signal,
It becomes possible to set a plurality of switching temperatures with one sensor, and the cooling fan and the water temperature switch, which was necessary for the number of set temperatures, are not required.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cooling fan control device according to the present invention will be described with reference to FIGS. Note that FIG. 1 is a system diagram of the cooling fan control device, and the same parts as those of the conventional structure shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the present invention, the engine ECU 21 serving as a controller has a water temperature sensor 3, a vehicle speed sensor 22, an engine rotation speed sensor 23 and an A / C switch (A / CSW).
The detection data of 24 is input, and the engine ECU 21 is configured to determine the drive mode of the radiator fan 4 and the condenser fan 5 by making a determination based on a flowchart described later. Further, the radiator fan 4 and the condenser fan 5 send a control output signal of LO (LOW) drive or HI (HIGH) drive to the engine E.
It receives from the common terminal of CU21, and both fans operate in the same drive mode. The water temperature sensor 3 and FIG.
As the vehicle speed sensor 22, the engine rotation speed sensor 23, and the A / CSW 24, which are not shown in FIG.

Next, the process of determining the drive mode in the engine ECU 21 will be described with reference to the flowchart of FIG. In addition, the numerical values of the water temperature and the vehicle speed used in the following description are examples, and the present invention is not limited thereto. First, determine whether the A / C switch 24 is ON or OFF,
When the A / C switch is ON, that is, when A / C is being used, the A / C refrigerant pressure SW11 is subsequently turned ON-OF.
Judge F. At this time, if the amount of A / C refrigerant is small, A / C
C Refrigerant pressure SW11 is turned on, and the cooling fan drive mode operates at high speed regardless of vehicle speed or water temperature.
It becomes I mode. Also, the A / C refrigerant pressure SW11 is OF
In the case of F, the water temperature of the cooling water is detected. When the water temperature is less than 105 ° C, the low speed operation is in LO mode, and when it is 105 ° C or more, it is in HI mode.

Although the above description is for the case where the A / C is used, next, the A / C switch 24 is turned off,
That is, the case where the A / C is not operated will be described. In this case, the vehicle speed is detected, but the vehicle speed is 45 km / H.
In the low speed range of less than, it is judged whether the water temperature is less than 95 ° C. If it is less than 95 ° C, it is judged that the fan drive is not necessary and the operation is stopped in the OFF mode. Further, it is determined whether the water temperature is less than 105 ° C. When the water temperature at this time is less than 105 ° C, the LO mode is set, but when it is 105 ° C or more, the HI mode is set.

In the medium speed range where the vehicle speed is 45 Km / H or more and less than 80 Km / H, it is judged whether the water temperature is less than 90 ° C., and 9
When the temperature is lower than 0 ° C., it is determined that the water temperature of the cooling water is sufficiently low, and the OFF mode is set. When the temperature is 90 ° C. or higher, it is further determined whether the water temperature is lower than 105 ° C. When the water temperature at this time is less than 105 ° C, the LO mode is set, and the temperature is 105 ° C.
In the above cases, the HI mode is set.

Finally, in a high speed range of 80 km / H or more, it is judged whether the water temperature is less than 105 ° C. If the water temperature is less than 105 ° C, the OFF mode is set, and if it is 105 ° C or more, the HI mode is set. ..

FIG. 3 is a table showing the setting of the operation modes of the cooling fan based on such a flow chart. The operation of the present invention will be described with reference to this table. By adding
It is possible to finely set the drive mode when C is not used. That is, when the A / C switch 24 is ON, there is ON / OFF of the A / C refrigerant pressure SW11 and mode switching by water temperature, but mode switching by vehicle speed difference does not occur. This is because the cooling performance is improved by driving the condenser fan 5, and a part of the output of the engine 1 serves as a driving source of the A / C copressor 6 to increase the load, so that the heat generation amount of the engine 1 is increased and the radiator is increased. This is because the burden on On the other hand, when the A / C is not used, the load on the A / C compressor 6 is reduced, and the heat generation amount of the engine 1 is reduced accordingly. Further, it is not necessary to cool the condenser to improve the cooling performance. In such a situation, since sufficient traveling air can be obtained in the high speed range, the radiator has a high cooling capacity, and forced cooling by a cooling fan is not required when the temperature of the cooling water is lower than 105 ° C., which is relatively low. Next, in the medium speed range, running wind in the high speed range cannot be obtained, but the engine speed is low, and therefore, when the water temperature is as low as less than 90 ° C, forced cooling is not necessary.
Further, the cooling fan is sufficient to operate at a low speed at an intermediate temperature until the water temperature reaches a high temperature of 105 ° C or higher. Further, in the low speed range, although the traveling wind obtained is not small, the heat generation amount of the engine 1 is also small. Therefore, forced cooling is not required at a water temperature of less than 95 ° C., which is slightly higher than the medium speed range, and a cooling fan is sufficient at low speed operation at an intermediate temperature until the water temperature reaches a high temperature of 105 ° C. or higher.

As described above, the operation of the cooling fan is finely stopped or the range of low speed operation is widened to reduce the load of the alternator for supplying electric power to the drive motor of the cooling fan, and the engine output corresponding to that. It also saves fuel required for. Alternatively, since the output corresponding to the reduced load of the alternator can be used for traveling of the vehicle, improvement in drivability can be expected. Also, the cooling fan O
Increasing the driving modes of FF and LO also shortens the time of noise generation by the cooling fan.

By sharing the control drive signal of the radiator fan 4 and the condenser fan 5, the capacity of the engine ECU 21 can be small, and the water temperature switch is not required. It is valid.

In this embodiment, a radiator fan and a condenser fan for A / C were used as cooling fans, but in a vehicle not equipped with A / C, naturally there is no condenser fan. Needless to say, the cooling fan control device of the present invention can be applied to such a case as well, and the A / C switch 24 in the above-described embodiment may be controlled to be turned off.

[0020]

According to the cooling fan control device of the present invention described above, by adding the condition of the vehicle speed to the water temperature, it becomes possible to control the driving of the cooling fan of high performance with a finer degree of fineness, fuel consumption and driver. Effective in improving abilities. In addition, there is an effect that the time when the cooling fan emits noise can be reduced. Further, since the water temperature switch is not required, conventional sensors can be used as they are, and the capacity of the engine ECU can be small, the cost and the vehicle mountability are excellent.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a cooling fan control device according to the present invention.

FIG. 2 is a flowchart showing an example of a process of determining a drive mode in the engine ECU of FIG.

FIG. 3 is a table of drive modes defined based on the flowchart of FIG.

FIG. 4 is a system diagram showing a conventional example.

[Explanation of symbols]

 1 Engine 2,21 Engine ECU 3 Water Temperature Sensor 4 Radiator Fan 5 Condenser Fan 6 A / C Compressor 7,8,9 Switch (Water Temperature SW) 10 Power Supply 11 A / C Refrigerant Pressure Switch 22 Vehicle Speed Sensor 23 Engine Rotation Speed Sensor 24 A / C switch

Claims (1)

[Claims] 1. A cooling fan control device for a vehicle, which is driven by using a part of an engine output of an automobile as a drive source, a cooling fan driven by an electric motor, and a vehicle speed sensor for detecting a traveling speed of the own vehicle. A cooling comprising a water temperature sensor for detecting a water temperature of engine cooling water, and a controller for determining a drive mode of the cooling fan according to a combination condition of the vehicle speed and the water temperature detected by the vehicle speed sensor and the water temperature sensor. Fan controller.