JP2000220453A - Cooling fan control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the life of a fan motor by providing a PTC heater for heating a thermostat for regulating the quantity of cooling water carried to a radiator, and ON-operating the fan motor when the temperature of cooling water is not lower than a set water temperature in the ON-operation of the PTC heater. SOLUTION: In an ECU 44 having detecting means for detecting atmospheric pressure, throttle opening, engine rotating speed, intake air temperature, cooling water temperature, and ON/OFF state, etc., of air conditioner, and inputting the output signals thereof, the traveling state of a vehicle or the operating state of an internal combustion engine 2 is judged, and a PTC heater 40 is ON/OFF-controlled on the basis of the judgment result. When it is judged that the temperature of the cooling water in the ON-operation of the PTC heater 40 is a set water temperature or higher, a fan motor 24 is controlled to be ON. When a climbing state is judged, the internal combustion engine is in thermally damaged state, or the throttle opening is a prescribed opening or more, the fan motor 24 is ON.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling fan control device for a vehicle, and more particularly to a vehicle cooling fan control device, which can improve power performance, improve cooling performance, extend the life of a fan motor, and improve fuel efficiency. The present invention relates to a cooling fan control device for a vehicle that can perform the following.

[0002]

2. Description of the Related Art In a water-cooled internal combustion engine mounted on a vehicle, the amount of cooling water to a radiator is adjusted by a thermostat in accordance with the temperature of the cooling water in order to maintain the cooling water at a constant temperature. The thermostat opens and closes a valve body in accordance with the temperature of the cooling water with a built-in wax or the like, and adjusts the amount of the cooling water flowing to the radiator.

Some of the thermostats include a PTC heater that is turned on and off. A thermostat equipped with a PTC heater can turn on the PTC heater to warm wax and the like, thereby opening the valve body greatly, flowing a large amount of cooling water to the radiator, and lowering the temperature of the cooling water.

As such a thermostat, there is one disclosed in Japanese Patent Application Laid-Open No. 9-303147. What is disclosed in this publication is to provide an electric resistance heating element in a constant temperature control valve, and to heat the mixed wax by the resistance heating element to increase the volume, thereby setting the temperature level of the switching valve to at least two different temperature levels. Is to switch to.

[0005] The cooling water flowing to the radiator is:
It is cooled by heat exchange with outside air and traveling wind, and is cooled by cooling air of a radiator fan driven by a fan motor.

A cooling fan control device for controlling a fan motor of such a cooling fan is disclosed in Japanese Utility Model Laid-Open No. 60-13 / 1985.
Nos. 7116, 58-75007, 61-36122, and 3-70811.

Japanese Unexamined Utility Model Publication No. 60-137116 discloses that a temperature switch is installed at a plurality of portions of an engine having different temperature rising characteristics, and at least one of the temperature switches has reached a temperature limit at the time of heating. Is detected, the cooling fan is driven, and when it is detected that all the temperature switches have reached the temperature-lowering limit temperature, the cooling fan is stopped.

Japanese Unexamined Utility Model Application Publication No. 58-75007 discloses a heater unit that uses a heater core controlled by a manual switch to generate hot air through a heater core and introduces the hot air into a vehicle interior. In a vehicle equipped with a circuit, a circuit for activating a heater fan when a temperature of a cooling water exceeds a predetermined value and a thermoswitch is activated, and prevents a warm air from a heater core from being introduced into a vehicle compartment when the heater fan is not activated. Means are provided.

A cooling water temperature control apparatus disclosed in Japanese Utility Model Laid-Open Publication No. 61-36122 has a main radiator, a sub radiator, an electric fan for a sub radiator, and a preheating heater for preheating cooling water to a heater core. The drive of the sub-radiator electric fan is controlled by the cooling water temperature.

Japanese Unexamined Patent Publication No. 3-70811 discloses a heater use condition determining means for determining a room heater use condition based on a temperature-related parameter, and a blower fan blowing amount of the room heater when the room heater use condition is satisfied. A cooling fan drive control temperature setting means for setting a cooling fan drive control temperature of the radiator in accordance with the cooling fan drive control temperature, and outputting a cooling fan drive signal based on a temperature-related parameter and an operation state parameter based on the set cooling fan drive control temperature. And a cooling fan drive determining means for determining whether or not the cooling fan is driven.

[0011]

The cooling fan control device drives the cooling fan by turning on the fan motor in a state where a large amount of cooling water flows through the radiator by turning on the PTC heater of the thermostat. By doing so, it is possible to obtain a larger water temperature drop (ΔT), thereby improving the power performance and the cooling performance.

However, if control is performed so that the fan motor is turned on in all the states where the PTC heater is turned on, there is a disadvantage that the life of the fan motor is shortened, and there is a possibility that fuel efficiency may be deteriorated.

Therefore, recently, there has been a demand for a cooling fan control device capable of improving the power performance and the cooling performance, extending the life of the fan motor, and improving the fuel efficiency.

[0014]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a thermostat for adjusting the amount of cooling water flowing to a radiator in accordance with the temperature of cooling water for an internal combustion engine mounted on a vehicle in order to eliminate the above-mentioned disadvantages. PTC that is turned on and off to operate by heating this thermostat
Providing a heater, providing a fan motor for driving a cooling fan of the radiator, determining at least one of a running state of the vehicle and an operating state of the internal combustion engine, and turning on the PTC heater based on the determination result. A control means is provided for controlling the fan motor to be turned on when the temperature of the cooling water during the cooling operation is equal to or higher than a set water temperature.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cooling fan control device according to the present invention provides a cooling fan control device for controlling the temperature of cooling water when a PTC heater is turned on based on at least one determination result of a running state of a vehicle and an operating state of an internal combustion engine. Is higher than the set water temperature,
By controlling the fan motor of the cooling fan to be turned on, the PTC heater is not turned on in all the states where the PTC heater is turned on.
When the heater is turned on, the fan motor can be turned on only when the importance and the effect are high.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show an embodiment of the present invention. In FIG. 2, reference numeral 2 denotes an internal combustion engine mounted on a vehicle (not shown). The internal combustion engine 2 has a cylinder block 4, a cylinder head 6, and an oil pan 8.
The internal combustion engine 2 has a block-side water jacket 10 provided on the cylinder block 4 and a head-side water jacket 12 provided on the cylinder head 6.

A radiator 1 is provided in front of the internal combustion engine 2.
4 are installed. The radiator 14 includes a core 16, an upper tank 18, and a lower tank 20. Core part 1
6, a cooling fan 2 for cooling the radiator 14 is provided.
2 are provided. The cooling fan 22 is driven by a fan motor 24. The fan motor 24 is turned on by the fan motor power supply. The upper tank 18
Is connected to the head side water jacket 12 by an inlet hose 26. The lower tank 20
Is connected to the block side water jacket 10 by an outlet hose 28.

One end of a bypass hose 30 is connected to the inlet hose 26 near the connection portion with the head side water jacket 12. Bypass hose 3
The other end of 0 is provided so as to be in contact with the vicinity of a connection portion of the outlet hose 28 with the block-side water jacket 10. A thermostat 32 is provided at a portion of the inlet hose 26 to which the bypass hose 30 is connected.

The thermostat 32 opens and closes a valve body 38 by a wax 36 incorporated in a housing 34, and the inlet hose 26 of the head-side water jacket 12.
And the degree of opening with respect to the bypass hose 28 are adjusted. Thereby, the thermostat 32 adjusts the amount of the cooling water flowing to the radiator 10 according to the temperature of the cooling water of the internal combustion engine 2, and optimizes the temperature of the cooling water in the internal combustion engine 2.

The thermostat 32 has a wax 36.
Is provided with a PTC heater 40 for heating the PTC heater. When the PTC heater 40 is supplied with PTC power and is turned on, the resistance value of the PTC heater 40 increases as the temperature increases. The thermostat 32 heats the wax 36 by turning on the PTC heater 40 to connect the valve body 38 to the inlet hose 26.
Side, the cooling water temperature is lowered by flowing a large amount of cooling water to the radiator 14 side.

The fan motor 24 of the cooling fan 22 and the PTC heater 40 of the thermostat 32 are connected to control means 44 of a cooling fan control unit 42.
The control means 44 includes an atmospheric pressure sensor 46 for detecting an atmospheric pressure PA, a vehicle speed sensor 48 for detecting a vehicle speed SPD, a throttle sensor 50 for detecting a throttle opening TA, and an engine speed NE (crank angle). Engine speed sensor (crank angle sensor) 52 and intake air temperature TH
A, an intake air temperature sensor 54 for detecting A, and a cooling water temperature THW.
And a battery 58 for supplying power VB.

Further, the control means 44 inputs an ON signal for idling operation of the internal combustion engine 2 so that the idle switch 6
0, an air conditioner switch 62 for inputting a signal when an air conditioner A / T (not shown) is turned on, and an ignition switch 64 for inputting a signal when an ignition key (not shown) is turned on. It is provided.

The control means 44 receives these various signals, determines the running state of the vehicle and / or the operating state of the internal combustion engine 2, and controls the PTC heater 40 to turn on and off based on the determination result. In addition, when at least one of the running state of the vehicle and the operating state of the internal combustion engine 2 is determined, and the temperature of the cooling water when the PTC heater 40 is turned on based on the determination result is equal to or higher than the set water temperature Is controlled so that the fan motor 24 is turned on.

The control means 44 controls the PTC heater 40 to be turned on when it is determined that the vehicle is running and / or the internal combustion engine 2 is running uphill.

The determination of the uphill state is performed based on the flowchart of FIG. When the program starts (step 100), first, the current engine speed NE (r) is constantly obtained at a constant cycle R (ms) from the map STMAP of the hill determination throttle opening STA in FIG.
pm) and the vehicle speed SPD (Km / h), the slope opening determination throttle opening STA (deg) is obtained, and as the slope determination condition, the throttle opening TA ≧ the slope determination throttle opening ST
It is determined whether or not A has continued for a predetermined time H (sec) (step 102).

If the determination (step 102) is YES, it is determined that the vehicle is going uphill and the flag 1 is set (step 104). On the other hand, if this determination (step 102) is NO, it is determined whether or not the flag is currently 1 (step 208). This determination (step 106) is YES
In the case of, the condition for canceling the uphill determination is that the throttle opening TA <the uphill determination throttle opening STA is equal to the predetermined time I (s
ec) It is determined whether or not the processing has been continued (step 108).

If the determination (step 108) is YES, it is determined whether the idle switch 60 is on (step 110). This judgment (step 110) is Y
In the case of ES and when the determination (step 106) is NO, it is determined that the vehicle is in the uphill state, and the flag 1 is set (step 104).

On the other hand, if the judgment (step 106) is NO
In the case of (1) and when the determination (step 110) is NO, it is determined that the vehicle is not in the uphill state, and the flag is set to 0 (step 112). When the ignition switch 64 is turned off, the uphill determination is cleared.

The reason why the PTC heater 40 is constantly turned on when it is determined that the vehicle is climbing a hill is that power performance is most required when climbing a hill and that cooling performance is severe. Even in cold weather, the engine speed NE and the engine load are high when climbing a hill, so that sufficient heater capacity can be ensured, and the PTC heater 40 does not need to be turned off.

The control means 44 controls the PTC heater 40 to be turned on when the heat damage state is determined as the running state of the vehicle and / or the operating state of the internal combustion engine 2.

The determination of the heat damage state is performed based on the flowchart of FIG. When the program starts (step 200), the vehicle speed SPD <the set vehicle speed J (Km /
h) is determined (step 202). If this determination (step 202) is YES, the intake air temperature TH
It is determined whether or not A ≧ set intake air temperature K (° C.) (step 204). If this determination (step 204) is YES, it is determined that the apparatus is in the heat damage state, and flag 1 is set (step 2).
06).

On the other hand, if the judgment (step 202) is NO
In this case, it is determined whether or not the intake air temperature THA ≧ the set intake air temperature L (° C.) (step 208). Here, the set intake air temperatures K and L have a relationship of K> L. If the determination (step 208) is YES, it is determined that the apparatus is in a heat damage state,
Flag 1 is set (step 206). On the other hand, if the determination (step 208) is NO, it is determined that the vehicle is not in the heat damage state, and the flag is set to 0 (step 210).

If the determination (step 204) is NO
, The air conditioner switch 62 is on and the vehicle speed S
It is determined whether or not PD <set vehicle speed S (Km / h) (step 212). If this determination (step 212) is YES, it is determined that a heat damage has occurred, and the flag 1 is set (step 206). If the determination (step 212) is NO, it is determined that the state is not the heat damage state, and the flag is set to 0 (step 210). When the ignition switch 64 is turned off, the heat damage determination is cleared.

As described above, the PTC heater 40 is always turned on when it is determined that the heat damage has occurred. In the thermostat 32, the set temperature for the operation of the wax 36 is basically raised. In case of heat damage, PTC heater 4
This is because if 0 remains off, the cooling capacity will be insufficient. Further, since the valve opening temperature at the time of the ON operation of the PTC heater 40 becomes lower than the conventional temperature, the cooling capacity is improved by continuing the PTC heater 40 to the ON operation.

Further, when the control means 44 determines a low temperature state as the running state of the vehicle and / or the operating state of the internal combustion engine 2, the control means 44 removes the PTC state except the uphill state and the heat damage state.
Control is performed to turn off the heater 40.

The determination of the low temperature state is based on the intake air temperature THA ≦
When it is the set intake air temperature N (° C.), it is determined to be in a low temperature state,
Flag 1 is set. Intake air temperature THA ≦ set intake air temperature N
If not (° C.), if the intake air temperature THA> the set intake air temperature N (° C.) and the vehicle speed SPD ≧ the set vehicle speed P (Km / h) has continued for a predetermined time Q (sec), it is determined that the vehicle is not in a low temperature state. , Flag 0. The intake air temperature THA> set intake air temperature N (° C.) and vehicle speed SPD ≧ set vehicle speed P (Km
/ H) does not continue for a predetermined time Q (sec), the current flag is continued as it is. When the ignition switch 64 is turned off, the low temperature determination is cleared and the flag becomes 0.

As described above, the PTC heater 40 is always turned off in the low temperature state except for the uphill state and the heat damage state, because the heater performance is more important than the power performance at the low temperature. It is.

Further, the control means 44 determines whether the running state of the vehicle and / or the operation state of the internal combustion engine 2 is in a high altitude state and removes the PTC heater 4 except for the low temperature state.
0 is turned on.

This high altitude state is determined based on the atmospheric pressure PA <the set atmospheric pressure B (mmHg). In a high altitude state, the PTC heater 40 is always turned on except in a low temperature state, because the output of the internal combustion engine 2 is reduced at a high altitude,
This is because the power performance is ensured by turning on the PTC heater 40.

The control means 44 controls the PTC heater 40 when it determines that the vehicle is running and / or the idling operation state as the operation state of the internal combustion engine 2 except for an uphill state, a heat damage state, and an altitude state. Control to operate off.

This idle operation state is determined when the idle switch 60 is on. In the idling operation state, basically, the PTC heater 40 is turned off to reduce fuel consumption and vibration. When the temperature of the cooling water rises, the atomization of the fuel is promoted to stabilize the combustion, so that the rotation speed can be reduced and the fuel efficiency can be greatly reduced. On the other hand, in an uphill state, a heat damage state, and a high altitude state, the PTC heater 40 is turned on to improve the cooling performance and the power performance at the time of starting.

Further, the control means 44 controls to turn on the PTC heater 40 except for the low-temperature state, when the high-speed running state is determined as the running state of the vehicle and / or the operating state of the internal combustion engine 2.

This high-speed running state is determined by vehicle speed SPD> set vehicle speed C (Km / h). In the high-speed running state, the PTC heater 40 is always turned on except in a low-temperature state, because power performance is required at a high speed, and it is necessary to lower the temperature of the cooling water. Since the engine speed NE and the engine load are high,
This is because the friction loss, pumping loss, and cooling loss of the internal combustion engine 2 become relatively small. For this reason, in high-speed running, even if the temperature of the cooling water is raised, the effect of reducing fuel consumption is small, so that the temperature of the cooling water is lowered to avoid occurrence of hunting of the water temperature.

Further, when the control means 44 determines that the traveling state of the vehicle and / or the driving state of the internal combustion engine 2 is a general road traveling state, the throttle opening TA is set to a predetermined throttle opening F except for a low temperature state. (Deg) or more, that is, throttle opening degree TA ≧ set throttle opening degree F (de
In g), the PTC heater 40 is turned on.

The general road traveling state is the low-side set vehicle speed D.
(Km / h) ≦ vehicle speed SPD ≦ higher set vehicle speed C (Km / h
h). When the vehicle is traveling on a general road, the PTC heater 40 is turned off in order to place more importance on fuel consumption performance than power performance when the vehicle is running smoothly on a general traffic flow. When accelerating, power performance is required,
The PTC heater 40 is turned on. However, since it takes several seconds from when the PTC heater 40 is turned on to when the temperature of the cooling water starts to decrease, the torque of the internal combustion engine 2 does not improve immediately after the accelerator pedal is depressed.

The control means 44 turns off the PTC heater 40 except for the uphill state, the heat damage state and the high altitude state, when the running state of the vehicle and / or the running state of the internal combustion engine 2 is determined to be the city running state. Control to work.

In this city running, vehicle speed SPD <set vehicle speed D
(Km / h). In city driving conditions,
This is because if the control such as the above-mentioned general road running is performed, the PTC heater 40 is frequently turned on and off, and hunting occurs in the temperature of the cooling water. This is because, in most cases, it is within several seconds, and during this time, the temperature of the cooling water does not decrease even if the PTC heater 40 is turned on.

Further, the control means 44 controls the temperature T of the cooling water.
Upper limit value A (° C) and lower limit value G (° C) as limit values for HW
Is set, and a guard based on this limit value is provided to control the PTC heater 40 to turn on and off. That is, when the water temperature THW ≧ the upper limit value A (° C.), the PTC heater 40 is turned on in any case. On the other hand, the water temperature THW
<Lower limit G (° C), PTC in any case
The heater 40 is turned off.

As described above, the provision of the guard for the water temperature THW based on the limit value is performed depending on the running conditions of the vehicle, even if the temperature of the cooling water rises abnormally, when the PTC heater 40 does not turn on, or when the cooling water is turned on. This is because there is a possibility that the PTC heater 40 may not be turned off in spite of the fact that the temperature is sufficiently low.

When the heater switch 66 of the heater (not shown) and the blower switch 68 of the blower (not shown) are connected,
When the switch 6 is on and the blower switch 68 is on, it is determined that the vehicle is running and / or the internal combustion engine 2 is operating at a low temperature.

This low temperature state is determined as a low temperature state when the heater switch 66 is on and the blower switch 68 is on, and is set to the flag 1. When the heater switch 66 is not on, the low temperature state is determined. And set the flag to 0.

The PTC heater 40 by the control means 44
Is performed based on the flowchart of FIG.

When the program is started (step 300), the control means 44 firstly sets a condition that the water temperature THW ≧ the upper limit value A
It is determined whether or not this is the case (step 302). If the determination (step 302) is YES, the PTC heater 40 is turned on (step 304).

On the other hand, this determination (step 302) is NO
In the case of, it is determined that the vehicle is in the uphill state, and it is determined whether the flag is 1 (step 306). If this determination (step 306) is YES, it is determined whether or not water temperature THW ≧ lower limit value G (step 308). If the determination (step 308) is YES, the PTC heater 40 is turned on (step 304). This judgment (step 3
If 08) is NO, the PTC heater 40 is turned off (step 310).

If the judgment (step 306) is NO, it is judged that a heat damage state has occurred and it is judged whether or not the flag is 1 (step 312). This judgment (step 31)
If 2) is YES, the judgment (step 308)
Move to

If the judgment (step 312) is NO, it is judged that the temperature is low, and it is judged whether or not the flag is 1 (step 314). This judgment (step 31)
If 4) is YES, the PTC heater 40 is turned off (step 310).

If the determination (step 314) is NO, it is determined whether or not the atmospheric pressure PA <the set atmospheric pressure B (3).
16). If this determination (step 316) is YES, the process proceeds to the determination (step 308).

If the determination (step 316) is NO, it is determined whether the idle switch 60 is on (step 318). This judgment (step 318)
Is YES, the PTC heater 40 is turned off (step 310).

If the determination (step 318) is NO, it is determined whether the vehicle speed SPD is greater than the set vehicle speed C (step 320). If the determination (step 320) is YES, the process proceeds to the determination (step 308).

If the determination (step 320) is NO, it is determined whether the low-side set vehicle speed D ≦ the vehicle speed SPD ≦ the high-side set vehicle speed C (step 322). If this determination (step 322) is YES, the throttle opening degree TA ≦≦
It is determined whether or not the throttle opening F is set (step 32).
4). If this determination (step 324) is YES, the process proceeds to the determination (step 308).

When the judgment (step 322) is NO and when the judgment (step 324) is NO, P
The TC heater 40 is turned off (step 310).

As described above, the control means 44 determines the running state of the vehicle and / or the operating state of the internal combustion engine 2 and turns on and off the PTC heater 40 based on the result of this determination, thereby making the PTC heater 40 Unnecessary ON / OFF operation is reduced, hunting is prevented from occurring in the temperature of the cooling water, the durability of the PTC heater 40 is improved, and the temperature of the cooling water is properly maintained, and various performances are improved. Can be improved.

That is, when climbing a hill, the PTC heater 40 is turned on to improve the power performance and the cooling performance. In the event of heat damage, the PTC heater 40 is turned on to improve the cooling performance. The PTC heater 40 is turned off to improve the heater performance.
The power performance is improved by turning on the heater 40, and during idle operation, the PTC heater 40 is turned off to improve fuel efficiency. During high-speed driving, the PTC heater 40 is turned on to improve power performance and improve cooling performance. Hunting is reduced at the temperature of the vehicle.
The power performance is improved by turning on the TC heater 40, the PTC heater 40 is turned off during steady driving to improve fuel efficiency, and the hunting occurs in the temperature of the cooling water by turning off the PTC heater 40 during city driving. The PTC heater 40 can be reliably turned on and off by providing a guard based on a limit value for the temperature of the cooling water.

The cooling fan control unit 42 determines at least one of the running state of the vehicle and the operating state of the internal combustion engine 2 by the control means 44, and turns on the PTC heater 40 based on the determination result. When the temperature of the cooling water is higher than the set water temperature, the fan motor 24 is controlled to be turned on.

When the control means 44 of this embodiment determines that the vehicle is traveling uphill, the internal combustion engine 2
When it is determined that the vehicle is in the heat damage state as the operating state, it is also determined that the vehicle speed is in the set vehicle speed range as the running state of the vehicle and that the throttle opening is not less than the set throttle opening as the operating state of the internal combustion engine 2. In such a case, the fan motor 24 is controlled to be turned on.

Next, the fan motor 2
Control 4 will be described with reference to FIG.

When the program starts (step 400), the control means 44 determines that the vehicle is in the uphill state by the uphill determination shown in FIGS. 4 and 5, and determines whether or not the flag is 1 (step 402). This judgment (Step 40)
If 2) is YES, the PTC heater 40 is turned on (step 404), and it is determined whether or not the water temperature THW ≧ the set water temperature T (step 406).

If the determination (step 406) is YES, the fan motor 24 is turned on (408).
If this determination (step 406) is NO, the water temperature T
It is determined whether or not HW <set water temperature U (step 41)
0). The set water temperatures T and U have a relationship of U ≦ THW <T. This is a hysteresis of the condition for turning on the fan motor 24.

If the determination (step 410) is YES, the fan motor 24 is turned off (step 4).
12). If this determination (step 410) is NO, it is determined whether the fan motor 24 is currently on (step 414).

If the judgment (step 414) is YES, the process shifts to the above-mentioned processing (step 408). If this determination (step 414) is NO, the fan motor 24 is turned off (step 412).

On the other hand, if the judgment (step 402) is NO
In the case of (1), the heat damage is determined by the heat damage determination shown in FIG. 6 and it is determined whether or not the flag is 1 (step 416). If this determination (step 416) is YES, the process proceeds to the above-described processing (step 404). If this determination (step 416) is NO, the low side setting vehicle speed D ≦ the vehicle speed SPD ≦ the high side setting vehicle speed C is determined by the general road traveling determination shown in (step 322) and (step 324) of FIG. It is determined whether or not the throttle opening TA ≦ the set throttle opening F (step 418).

If the determination (step 418) is YES, the process shifts to the processing (step 404). If this determination (step 418) is NO, the fan motor 24 is turned off (step 412).

As described above, the cooling fan controller 42
Determines at least one of the running state of the vehicle and the operating state of the internal combustion engine 2, and based on the result of the determination, determines whether the temperature THW of the cooling water when the PTC heater 40 is turned on is equal to or higher than the set water temperature T. In some cases, control is performed to turn on the fan motor 24 of the cooling fan 22.

That is, the cooling fan control unit 42
When the temperature THW of the cooling water is equal to or higher than the set water temperature T in the uphill state in which the C heater 44 is on, the heat damage state, and the traveling state on a general road, the fan motor 24 is turned on to activate the cooling fan 22. By driving, the fan motor 24 is not turned on in all of the states in which the PTC heater 40 is turned on. In the state in which the PTC heater 40 is turned on, the above-described uphill state, which is a state of high importance and high effect, is performed. The fan motor 24 can be turned on only in the heat damage state and the general road running state.

Therefore, the cooling fan controller 42
Is the fan motor 24 when the PTC heater 40 is turned on.
By turning on, a larger water temperature drop (△
T) can be obtained, whereby the power performance and the cooling performance can be improved.

The cooling fan control device 42
The fan motor 24 is not turned on in all the states where the TC heater 40 is turned on, and the fan motor 24 is turned on only in a state of high importance and high effect. It can improve fuel economy.

In this embodiment, the on / off operation of the fan motor 24 of the radiator 14 is controlled. However, for example, when a vehicle is equipped with an air conditioner A / T, a condenser fan for driving a condenser fan is provided. The on / off operation of the motor can be controlled, and when the vehicle is equipped with a heater, the on / off operation of the blower motor that drives the blower can also be controlled.

Therefore, the cooling fan controller 42
When a plurality of cooling fans are provided, each fan motor can be independently controlled according to the running state of the vehicle and the operating state of the internal combustion engine 2.

In the above-described embodiment, the cooling fan control device 42 exemplifies the uphill state, the heat damage state, and the general road running state as the state of high importance and high effect of turning on the fan motor 24. Alternatively, the fan motor 24 can be turned on when restarting the warm-up operation or during traffic congestion at high temperatures. Further, when the fan motor 24 is turned on, the fan motor 24 is controlled to rotate at a rotational speed set stepwise according to the temperature of the cooling water.
Can be appropriately driven. Furthermore, the fan motor 24 sets the set temperature T for the ON operation to be high, and controls so that the number of revolutions at the time of the ON operation is increased.
A large amount of cooling air with a large temperature difference can be supplied by the high-speed cooling fan 22, and a larger water temperature drop (ΔT) can be obtained, whereby power performance and cooling performance can be improved.

[0080]

As described above, the cooling fan control device according to the present invention does not turn on the fan motor in all the states where the PTC heater is turned on, but has the importance and the effect when the PTC heater is turned on. The fan motor can be turned on only in the high state.

For this reason, this cooling fan control device
By turning on the fan motor when the TC heater is turned on, a larger water temperature drop can be obtained,
Thereby, power performance and cooling performance can be improved. In addition, the cooling fan control device does not turn on the fan motor in all the states where the PTC heater is turned on, but turns on the fan motor only in the state of high importance and effect, so that the fan motor is turned on. The durability of the motor can be improved, and the fuel efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a flowchart of control of a cooling fan control device according to the present invention.

FIG. 2 is a system configuration diagram of a cooling fan control device.

FIG. 3 is a flowchart of control of a PTC heater.

FIG. 4 is a flowchart for determining a climbing state;

FIG. 5 is a diagram for setting an uphill determination throttle opening when determining uphill conditions.

FIG. 6 is a flowchart for determining a heat damage state.

[Explanation of symbols]

 2 Internal combustion engine 14 Radiator 22 Cooling fan 24 Fan motor 32 Thermostat 40 PTC heater 42 Cooling fan controller 44 Control means

Claims (4)

[Claims] 1. A thermostat for adjusting the amount of cooling water flowing to a radiator according to the temperature of cooling water of an internal combustion engine mounted on a vehicle is provided, and the thermostat is turned on and off so as to operate by heating the thermostat. Provide PTC heater,
Providing a fan motor for driving a cooling fan of the radiator, determining at least one of a running state of the vehicle and an operating state of the internal combustion engine, and turning on the PTC heater based on a result of the determination. A control means for controlling to turn on the fan motor when the temperature of the cooling water is equal to or higher than a set water temperature. 2. The control unit according to claim 1, wherein the control unit controls the fan motor to be turned on when it is determined that the vehicle is traveling uphill. Vehicle cooling fan control device. 3. The control unit according to claim 1, wherein the control unit controls the fan motor to be turned on when it is determined that the operating state of the internal combustion engine is a heat damage state. 4. The cooling fan control device for a vehicle according to claim 1. 4. The controller according to claim 1, wherein the control means determines that the vehicle speed is within a set vehicle speed range as a running state of the vehicle and the throttle opening is equal to or greater than the set throttle opening as an operating state of the internal combustion engine. 2. A control means for controlling a motor to be turned on.
4. The cooling fan control device for a vehicle according to claim 1.