KR101786685B1 - Control apparatus and method for cooling fan of vehicle - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a cooling fan control apparatus for a vehicle, and more particularly, to a cooling fan control apparatus and method for a vehicle which can prevent a motor burnout by restricting a fan motor during winter.
To this end, a cooling fan control apparatus for a vehicle according to an embodiment of the present invention generates an operation signal for controlling a cooling fan installed in an engine room of a vehicle, a fan motor for driving the cooling fan, and the cooling fan, Wherein the controller is configured to provide the motor with an air conditioning refrigerant during the measurement time if the startup off time that the startup has been off exceeds the determinable time and the intake air is within the set temperature when the startup is on, The rate of change of the pressure can be confirmed and the fan motor can be constrained according to the change rate of the air conditioner refrigerant pressure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a cooling fan,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a cooling fan control apparatus for a vehicle, and more particularly, to a cooling fan control apparatus and method for a vehicle which can prevent motor burnout by restricting a fan motor during winter.

Generally, a vehicle generates a lot of heat in the engine. If the temperature rises above a certain temperature, there is a danger of explosion. Therefore, the temperature is lowered by circulating cooling water around the engine for cooling. The heated cooling water dissipates heat from the radiator, and a cooling fan is installed in the engine room of the vehicle to enhance the radiating effect of the radiator.

Such a cooling fan keeps the temperature of the cooling water at an appropriate condition, thereby preventing the engine from overheating and optimizing the performance of the engine. The cooling fan is mainly driven by a motor.

In cold regions, water or snow enters the cooling fan, which often causes freezing of the cooling fan. Therefore, when the cooling fan is frozen, it is not operated even under the cooling fan ON condition.

Generally, the cooling fan is not operated in cold regions, but when the driver depresses the defrost button due to mist or frost removal, the air conditioner operates and the refrigerant pressure of the air conditioner rises slightly. When the air conditioner refrigerant pressure reaches a certain level, the cooling fan reaches the operating range, but the cooling fan is not operated due to the motor restriction due to the freezing of the cooling fan. Further, when the restraint time is prolonged, there is a problem that the motor is burned down or, in the worst case, a fire occurs in the engine room.

When there is an outside temperature sensor, it was possible to deactivate the cooling fan at a subzero temperature. However, since the outside temperature can not be checked in a vehicle not equipped with an outside temperature sensor, the cooling fan can not be controlled to operate at a subzero temperature. Also, in the conventional case, when the cooling fan is operated under certain conditions, the cooling fan freezes and motor burnout occurs. This motor burnout causes overheating due to overheating of the engine, resulting in a lot of repair costs.

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

Embodiments of the present invention provide an apparatus and method for controlling a cooling fan for a vehicle capable of restraining a fan motor based on an intake air temperature and an air conditioner refrigerant pressure to prevent motor burnout during the winter season.

The embodiments of the present invention provide a vehicle cooling fan control apparatus and method for operating a cooling fan when the coolant temperature is equal to or higher than a reference temperature.

According to an embodiment of the present invention, a cooling fan installed in an engine room of a vehicle is provided. A fan motor for driving the cooling fan; And a controller for generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor, wherein the controller determines that the start-off time at which the start- And when the intake air temperature is within the set temperature, the change rate of the air conditioner refrigerant pressure during the measurement time is confirmed, and the fan motor is constrained according to the change rate of the air conditioner refrigerant pressure.

Also, the controller confirms a first rate of change of the air-conditioner refrigerant pressure during the first measurement time, and provides the operation signal to the fan motor during a second measurement time to operate the cooling fan through the fan motor, The second rate of change of the refrigerant pressure of the air conditioner during the second measurement time may be checked and the operation of the cooling fan may be stopped according to the first rate of change and the second rate of change.

The controller calculates a contrast value based on the first rate of change and the second rate of change, and determines whether the contrast value is below a criterion. If the contrast value is less than a criterion, The operation of the cooling fan can be stopped when the duration is not maintained.

The cooling fan control device for a vehicle further includes an intake temperature measurement unit for measuring an intake temperature; A water temperature measuring unit for measuring the temperature of the cooling water; A speed measuring unit for measuring a vehicle speed; And a pressure measuring unit for measuring a refrigerant pressure of the air conditioner.

In addition, the controller may provide the operating signal to the fan motor if the compressor is operating and the vehicle speed is zero, and may restrict the fan motor according to the rate of change of the air conditioner refrigerant pressure during the measuring time.

In addition, if the intake air temperature is lower than the minimum temperature, the controller turns off the compressor and the cooling fan is operated when the cooling water temperature is higher than the reference temperature while the air conditioner switch is turned off.

In another embodiment of the present invention, there is provided a method of controlling a cooling fan of a vehicular cooling fan control device, comprising the steps of: confirming a start-off time at which the startup is off when the startup is on; Determining whether the start-up off time exceeds a determinable time; Determining whether the intake air temperature is within a set temperature when the start-up off time exceeds the determinable time; And restricting the fan motor according to the change rate of the air conditioner refrigerant pressure during the measurement time when the intake air temperature is within the set temperature.

The embodiment of the present invention can prevent motor burn-out by restraining the fan motor by icing in the winter season.

Further, since the cooling fan is operated when the coolant temperature is equal to or higher than the temperature temperature, engine overheating due to overheating of the engine can be prevented.

In addition, effects obtainable or predicted by the embodiments of the present invention will be directly or implicitly disclosed in the detailed description of the embodiments of the present invention. That is, various effects to be predicted according to the embodiment of the present invention will be disclosed in the detailed description to be described later.

1 is a block diagram showing a cooling fan control apparatus for a vehicle according to an embodiment of the present invention.
2 is a flowchart illustrating a method of controlling a cooling fan for a vehicle according to an embodiment of the present invention.
3 is a diagram illustrating a method of controlling a cooling fan control method for a vehicle according to an embodiment of the present invention when the air conditioner switch is off.
4 is a flowchart illustrating a constraint detection method in a method for controlling a cooling fan for a vehicle according to an embodiment of the present invention.
5 is a view for explaining a constraint detection method in a cooling fan control method for a vehicle according to an embodiment of the present invention.
FIG. 6 is an exemplary diagram illustrating a first rate of change and a second rate of change in a method for controlling a cooling fan for a vehicle according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an operation principle of an embodiment of a vehicle cooling fan control apparatus and method according to the present invention will be described in detail with reference to the accompanying drawings and description. It should be understood, however, that the drawings and the following detailed description are exemplary and explanatory of various embodiments for effectively illustrating the features of the present invention. Therefore, the present invention should not be limited to the following drawings and descriptions.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The terms used below are defined in consideration of the functions of the present invention, which may vary depending on the user, intention or custom of the operator. Therefore, the definition should be based on the contents throughout the present invention.

In order to efficiently explain the essential technical features of the present invention, the following embodiments will appropriately modify, integrate, or separate terms to be understood by those skilled in the art to which the present invention belongs , And the present invention is by no means thereby limited.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a cooling fan control apparatus for a vehicle according to an embodiment of the present invention.

The vehicle cooling fan control apparatus 50 includes a state detector 100, a controller 110, an air conditioner switch 120, a compressor (compressor) 125, a relay 130, a connector 140, a blower assembly A blower assembly 150, and a cooling fan 160.

The status detector 100 detects information required to control the cooling fan 160. [ The state detector 100 includes an intake air temperature measurement unit 102, a velocity measurement unit 104, a pressure measurement unit 106, and a water temperature measurement unit 108.

The intake air temperature measuring unit 102 measures the intake air temperature, which is the temperature of the air flowing into the inside of the vehicle, and provides it to the controller 110.

The speed measuring unit 104 measures the vehicle speed, which is the speed of the vehicle, and provides the measured vehicle speed to the controller 110. [

The pressure measuring unit 106 measures the pressure of the refrigerant of the air conditioner and provides the measured pressure to the control unit 110.

The water temperature measuring unit 108 measures the cooling water temperature of the engine and provides the measured cooling water temperature to the controller 110. [

The controller 110 controls the status detector 100, the air conditioner switch 120, the compressor 125, the relays 130, and the air conditioner 120, which are components of the cooling fan control device 50 for cooling, to operate or stop the cooling fan 160 ), The connector 140, the blower assembly 150, and the cooling fan 160.

The controller 110 confirms the start-off time at which the startup was off when the startup was turned on. The controller 110 checks the rate of change of the air conditioner refrigerant pressure during the measurement time when the startup off time exceeds the determinable time and the intake air temperature is within the set temperature. The controller 110 controls the fan motor 157 to restrain or operate normally according to the change rate of the air conditioner refrigerant pressure. A method of controlling the cooling fan 160 in the controller 110 will be described in more detail with reference to FIGS. 2 to 5. FIG.

For this purpose, the controller 110 may be implemented with one or more processors operating according to a set program, and the set program may be one programmed to perform each step of the vehicle cooling fan control method according to an embodiment of the present invention have.

The air conditioner switch 120 turns on or off the air conditioner. That is, the air conditioner switch 120 can turn on or off the air conditioner by the driver or the controller 110.

When the air conditioner is turned on by the air conditioner switch 120, the compressor 125 compresses the refrigerant to high temperature and high pressure to operate the air conditioner.

The relay 130 provides an operation signal to the connector 140 under the control of the controller 110. [

The connector 140 receives an operation signal from the relay 130 to drive the fan motor 157. To this end, the connector 140 includes a high speed connection 143, a low speed connection 146, and a ground connection 149. The high speed connection part 143 is directly connected to the fan motor 157 and the low speed connection part 146 is connected to the fan motor 157 through the resistor 153. [ The ground connection 149 is connected to the fan motor 157 and the ground. Here, the high-speed connection unit 143, the low-speed connection unit 146, and the ground connection unit 149 may be composed of switches.

The connector 140 receives the low speed operation signal from the relay 130 and passes through the low speed connection part 146 to the register 153 to drive the fan motor 157. When the high-speed operation signal is received from the relay 130, the connector 140 drives the fan motor 157 through the high-speed connection unit 143.

The blower assembly 150 includes a fan motor 157 and a resistor 153.

The fan motor 157 rotates the blades included in the cooling fan 160 to operate the cooling fan 160.

The register 153 regulates the speed of the fan motor 157. That is, as the resistance value of the resistor 153 becomes larger, the speed of the fan motor 157 is driven at a lower speed.

The cooling fan 160 is driven by a fan motor 157 included in the blower assembly 150. The cooling fan 160 maintains the temperature of the cooling water at an appropriate condition to prevent the engine from overheating and to optimize the performance of the engine.

Hereinafter, a method of controlling the cooling fan 160 in the vehicle according to the embodiment of the present invention will be described with reference to FIGS. 2 to 6. FIG.

2 is a flowchart illustrating a method of controlling a cooling fan for a vehicle according to an embodiment of the present invention.

Referring to FIG. 2, the controller 110 determines whether startup is on (S210). At this time, the controller 110 can receive a start-on signal from an ignition detector (not shown) to check whether the start-up is on.

The controller 110 confirms the startup off time at which the startup is off (S215). That is, the controller 110 can count the time when the start-up is turned off before the start-up is turned on to check the start-off time.

The controller 110 determines whether the startup off time exceeds the determinable time (S220). At this time, the determinable time may indicate the reference time for judging that the vehicle is parked at night, and may be set by an operator or set by a predetermined algorithm (for example, a program and a probability model) . For example, the judging time may be 6 hours.

The reason for determining whether the start-off time exceeds the determinable time is to confirm that the vehicle is parked at night. When the vehicle is parked at night, it can be assumed that the intake temperature is the same as the outside temperature. Therefore, the fan motor 157 can be prevented from being burned down by using the intake temperature without the outside temperature sensor.

When the start-off time exceeds the determinable time, the controller 110 confirms intake-on (S225). At this time, the intake air temperature may be the temperature measured through the intake air temperature measurement unit when the vehicle is turned off.

The controller 110 determines whether the intake air temperature is within the set temperature (S230). That is, the controller 110 can determine whether the intake air temperature is below the maximum temperature or above the minimum temperature. Here, the maximum temperature and the minimum temperature represent a reference temperature for determining the temperature at which the cooling fan 160 can freeze, and may be set by an operator or may be set by a predetermined algorithm (for example, a program and a probability model) Lt; / RTI > For example, the highest temperature may be 7 ° C, and the lowest temperature may be -10 ° C.

The controller 110 determines whether the compressor 125 is operating if the intake air temperature is within the set temperature (S235). That is, the controller 110 can determine whether the compressor 125 is on or off when the intake air temperature is the minimum temperature or more and the temperature is the maximum temperature or less.

If the compressor 125 is operating, the controller 110 determines whether the vehicle speed is zero (S240). That is, when the compressor 125 is in operation, the controller 110 confirms the vehicle speed supplied from the speed measuring unit. The controller 110 determines whether the vehicle is in an idle state by determining whether the vehicle speed is zero. If the vehicle speed is zero, the controller 110 generates an operation signal for operating the cooling fan 160. At this time, the operation signal may be a low-speed operation signal for operating the cooling fan 160 at a low speed.

The controller 110 performs restraint detection on whether the fan motor 157 is restrained or normally operated (S245). This cooling fan constraint detection method will be described in detail with reference to FIG.

The controller 110 determines whether the restraint detection result is normal (S250).

If the result of the constraint detection is not normal, the controller 110 stops the operation of the cooling fan 160 (S255). That is, the controller 110 stops the operation of the cooling fan 160 and stops the operation of the compressor 125 when the restraint detection result is restrained.

On the other hand, if the constraint detection result is normal, the controller 110 goes to step S275 and operates the cooling fan 160. At this time, the method of controlling the normal cooling fan 160 is the same as or similar to the control method of the cooling fan 160 that is generally used, and thus a detailed description thereof will be omitted.

The controller 110 confirms whether the startup is off (S260). That is, the controller 110 can complete the cooling fan control when the startup is off.

On the other hand, if the start-off time is equal to or shorter than the determinable time, the controller 110 confirms the state of the immediately preceding cooling fan (S265). That is, if the start-off time is less than the determinable time, the controller 110 may determine that the vehicle is not parked at night, so that the controller 110 confirms the state of the cooling fan 160 that was previously determined to be turned on.

The controller 110 determines whether the state of the immediately preceding cooling fan is normal (S270).

The controller 110 activates the cooling fan 160 when the immediately preceding cooling fan state is normal (S275). If the intake air temperature exceeds the maximum temperature, the controller 110 can not normally operate the cooling fan 160 because it is not a cold weather. Thereafter, the controller 110 can confirm that the startup is off.

On the other hand, if the intake air temperature is lower than the minimum temperature, the controller 110 turns off the compressor 125 (S280).

The controller 110 determines that the compressor 125 is not operating or the vehicle speed is not 0 as a result of the determination in step S240 or if the controller 110 turns off the compressor 125 in step S280, (Step S285).

The controller 110 confirms the cooling water temperature (S290). That is, the controller 110 receives the cooling water temperature from the water temperature measurement unit 108 to control the cooling fan 160 when the air conditioner switch 120 is turned off, and confirms the supplied cooling water temperature. The controller 110 determines whether the cooling water temperature is equal to or higher than the reference temperature.

The controller 110 activates the cooling fan 160 when the cooling water temperature is equal to or higher than the reference temperature (S295). That is, when the cooling water temperature is higher than the reference temperature, the controller 110 may operate the cooling fan 160 to lower the engine temperature to prevent overheating of the engine. Here, the reference temperature represents a reference temperature for judging that an overheat occurs in the engine, and may be a predetermined value. For example, as shown in FIG. 3, the reference temperature 310 may be 105 ° C.

The controller 110 provides an activation signal to the fan motor 157 via the relay 130 and the connector 140 and operates the cooling fan 160 via the fan motor 157. [ Here, the actuating signal may be the high-speed actuating signal 320. Thus, the cooling fan 160 is operated at a high speed to lower the temperature of the engine.

FIG. 4 is a flowchart illustrating a constraint detection method in a method for controlling a cooling fan for a vehicle according to an embodiment of the present invention. FIG. 5 is a flowchart illustrating a constraint detection method of a vehicle cooling fan control method according to an embodiment of the present invention. And FIG. 6 is an exemplary diagram for explaining a first rate of change and a second rate of change in a method for controlling a cooling fan for a vehicle according to an embodiment of the present invention.

Referring to FIGS. 4 to 6, the controller 110 confirms a first rate of change of the refrigerant pressure during the first measurement time (S410). Here, the first measurement time may indicate a delay time when the controller 110 transmits an operation signal to the fan motor 157 through the relay 130 and the connector 140. The reason why the controller 110 delays the operation signal and transmits the delayed operation signal is to prevent a bug from occurring in the relay 130 and the connector 140. [ At this time, as shown in FIG. 5, the first measurement time 510 may be from 0 second to the first time. For example, the first time may be 0.5 seconds.

In other words, the controller 110 is supplied with the first air-conditioner refrigerant pressure from the pressure measuring unit 106 at a time of 0 seconds, and is supplied with the second air-conditioner refrigerant pressure from the pressure measuring unit 106 at the first time. The controller 110 calculates a first rate of change based on the first air conditioner refrigerant pressure and the second air conditioner refrigerant pressure. Here, the first rate of change may be expressed as a slope 610 as shown in FIG.

The controller 110 activates the cooling fan 160 during the second measurement time (S420). In other words, the controller 110 provides the activation signal to the relay 130 at the first time, and the relay 130 provides the activation signal to the connector 140. [ At this time, the operation signal may be a low-speed operation signal. The low speed connection part 146 of the connector 140 passes through the register 153 to drive the fan motor 157 when the low speed operation signal is received. Thus, the cooling fan 160 can be operated by the fan motor 157.

Here, as shown in FIG. 5, the second measurement time 530 may indicate a time when the cooling fan 160 is operated and may be a predetermined value. The second measurement time 530 may be from the first time to the second time. For example, the second time may be 3.5 seconds.

The controller 110 stops the operation of the cooling fan 160 at the second time (430).

The controller 110 confirms a second rate of change of the air conditioner refrigerant pressure during the second measurement time (S440). In other words, the controller 110 receives the third air-conditioner refrigerant pressure from the pressure measuring unit 106 at the first time and the fourth air-conditioner refrigerant pressure from the pressure measuring unit 106 at the second time. The controller 110 calculates a second rate of change based on the third air conditioner refrigerant pressure and the fourth air conditioner refrigerant pressure. Here, the second rate of change may be expressed as a slope 630 as shown in FIG.

The controller 110 determines whether the total measurement time exceeds the reference time (S450). That is, the controller 110 adds the first measurement time and the second measurement time to generate a total measurement time, and determines whether the total measurement time exceeds the reference time.

The controller 110 determines whether the contrast value is below the criterion of determination (S460). Specifically, the controller 110 calculates a contrast value based on the first rate of change and the second rate of change. That is, the controller 110 can calculate the contrast value through Equation (1).

[Equation 1]

C = B / A

Here, C may represent a contrast value, wherein A represents a first rate of change, and B represents a second rate of change.

The controller 110 determines whether the contrast value is below the determination standard. Here, the criterion is a reference value for judging whether the fan motor 157 is normally operated or restrained. For example, the criterion may be 0.7.

In step S470, the controller 110 determines whether the contrast value is equal to or less than the determination criterion and the duration is maintained from the time when the contrast value becomes less than the criterion. For example, the duration may be 2 seconds.

The controller 110 determines that the cooling fan 160 is normal when the duration is maintained (S480).

If the contrast value exceeds the criterion or the duration can not be maintained, the controller 110 determines that the fan motor 157 is constrained (S490).

As described above, the vehicle cooling fan control apparatus 50 according to the embodiment of the present invention determines whether or not the start-off time exceeds a determinable time based on the intake air flowing from the outside, The fan motor 157 can be restrained, so that motor burnout can be prevented.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

50: Cooling fan control device for vehicle
100: state detector
102: intake air temperature measuring unit
104: speed measuring unit
106: pressure measuring unit
108: Water temperature measuring unit
110:
120: Air conditioning switch
125: Compressor
130: Relay
140: Connector
150: Blower assembly
153: Register
157: Fan motor
160: Cooling fan

Claims (13)

A cooling fan installed in an engine room of a vehicle;
A fan motor for driving the cooling fan; And
A controller for generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor;
, ≪ / RTI &
The controller checks the first rate of change of the air conditioner refrigerant pressure during the first measurement time when the startup off time that the startup has been off exceeds the determinable time and the intake air temperature is within the set temperature when the startup is on Providing the operating signal to the fan motor for a second measurement time to operate the cooling fan through the fan motor to confirm a second rate of change of the refrigerant pressure during the second measurement time, And stopping the operation of the cooling fan according to the second rate of change,
Wherein the determination time indicates a reference time for determining that the vehicle is parked at night, the first measurement time indicates a time from when the startup is turned on to a time before the operation of the cooling fan starts, Wherein the measuring time indicates the time from the start of operation of the cooling fan to the stop of operation of the cooling fan. delete The method according to claim 1,
The controller
Calculating a contrast value based on the first rate of change and the second rate of change, determining whether the contrast value is less than or equal to a criterion, and determining whether the contrast value is less than a criterion, And stops the operation of the cooling fan when the duration is not maintained. The method according to claim 1,
An intake air temperature measuring unit for measuring an intake temperature;
A water temperature measuring unit for measuring the temperature of the cooling water;
A speed measuring unit for measuring a vehicle speed; And
A pressure measuring unit for measuring a refrigerant pressure of the air conditioner;
And a state detector including at least one of the following: < RTI ID = 0.0 > a < / RTI > The method according to claim 1,
The controller
Providing the operating signal to the fan motor when the compressor is in operation and the vehicle speed is zero and restricting the fan motor according to the rate of change of the air conditioner refrigerant pressure during the measuring time. The method according to claim 1,
The controller
Wherein when the intake air temperature is lower than the minimum temperature, the compressor is turned off and the cooling fan is operated when the cooling water temperature is equal to or higher than the reference temperature while the air conditioner switch is turned off. A method for controlling a cooling fan of a vehicular cooling fan control device,
Confirming a start-off time at which the start-up was off when the start-up is on;
Determining whether the start-up off time exceeds a determinable time;
Determining whether the intake air temperature is within a set temperature when the start-up off time exceeds the determinable time;
Confirming a first rate of change of the refrigerant pressure of the air conditioner during a first measurement time if the intake air temperature is within a set temperature;
Operating the cooling fan for a second measurement time;
Confirming a second rate of change of the air conditioner refrigerant pressure during the second measurement time; And
Stopping the operation of the cooling fan according to the first rate of change and the second rate of change;
, ≪ / RTI &
Wherein the determination time indicates a reference time for determining that the vehicle is parked at night, and the first measurement time indicates a time from when the startup is turned on to a time before the operation of the cooling fan starts, Wherein the measuring time is from a starting point of the cooling fan to a stopping point of the cooling fan. delete 8. The method of claim 7,
Stopping the operation of the cooling fan according to the first rate of change and the second rate of change
Calculating a contrast value based on the first rate of change and the second rate of change;
Determining whether the contrast value is below a criterion;
Determining whether a duration is maintained from a time point at which the contrast value is equal to or lower than a determination standard; And
Stopping the operation of the cooling fan when the duration is not maintained;
And a control unit for controlling the cooling fan. 10. The method of claim 9,
The contrast value is calculated through Equation (1)
Equation (1)
C = B / A
ego,
Here, C is a contrast value, A is a first change rate, and B is a second change rate. 8. The method of claim 7,
The step of restricting the fan motor according to the change rate of the air conditioner refrigerant pressure during the measurement time when the intake air temperature is within the set temperature
Determining whether the compressor is operating if the intake air temperature is within a set temperature;
Determining whether the vehicle speed is zero if the compressor is in operation; And
Restricting the fan motor according to a change rate of the air conditioner refrigerant pressure during the measurement time if the vehicle speed is zero;
And a control unit for controlling the cooling fan. 8. The method of claim 7,
Wherein the step of determining whether the intake air temperature is within the predetermined temperature
Determining whether the intake air temperature is lower than a maximum temperature; And
Determining whether the intake air temperature is equal to or lower than a minimum temperature when the intake air temperature is lower than a maximum temperature;
And a control unit for controlling the cooling fan. 8. The method of claim 7,
After the step of determining whether the intake air temperature is within the set temperature
Turning off the compressor if the intake air temperature is below the minimum temperature;
Measuring the temperature of the cooling water while the air conditioner switch is turned off; And
Operating the cooling fan if the cooling water temperature is higher than the reference temperature;
Further comprising the steps of:

Images