Title:
APPARATUS AND METHOD FOR CONTROLLING COOLING FAN OF VEHICLE
Kind Code:
A1


Abstract:
An apparatus and a method for controlling a cooling fan of a vehicle are capable of preventing a fan motor from being damaged by locking the fan motor in cold weather conditions. The apparatus includes: a fan motor driving the cooling fan; and a controller generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor, where the controller confirms an ignition-off time for which an ignition was turned off when the ignition is turned on, confirms a change rate of an air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and an intake air temperature is present within a predetermined temperature, and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure.



Inventors:
Kim, Yeoung Jun (Suwon, KR)
Park, Man Hee (Suwon, KR)
Kim, Taewan (Suwon, KR)
Oh, Dong Seok (Hwaseong, KR)
Application Number:
15/251211
Publication Date:
06/01/2017
Filing Date:
08/30/2016
Assignee:
Hyundai Motor Company (Seoul, KR)
Primary Class:
International Classes:
B60H1/00; B60H1/32; F01P11/16
View Patent Images:



Primary Examiner:
ARANT, HARRY E
Attorney, Agent or Firm:
Mintz Levin/Special Group (Boston, MA, US)
Claims:
What is claimed is:

1. An apparatus for controlling a cooling fan of a vehicle, the cooling fan being installed in an engine compartment of the vehicle, comprising: a fan motor driving the cooling fan; and a controller generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor, wherein the controller confirms an ignition-off time for which an ignition was turned off when the ignition is turned on, confirms a change rate of an air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and an intake air temperature is present within a predetermined temperature, and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure.

2. The apparatus of claim 1, wherein: the controller confirms a first change rate of the air conditioner refrigerant pressure for a first measurement time, operates the cooling fan through the fan motor by providing the operation signal to the fan motor for a second measurement time, confirms a second change rate of the air conditioner refrigerant pressure for the second measurement time, and stops the operation of the cooling fan depending on the first change rate and the second change rate.

3. The apparatus of claim 2, wherein: the controller calculates a comparison value on the basis of the first change rate and the second change rate, decides whether or not the comparison value is less than or equal to a decision reference, and stops the operation of the cooling fan in the case in which the comparison value is not maintained for a duration in a state in which the comparison value is less than or equal to the decision reference.

4. The apparatus of claim 1, further comprising: a state detector including at least one of: an intake air temperature measurer measuring the intake air temperature, a coolant measurer measuring a coolant temperature, a speed measurer measuring a vehicle speed, and a pressure measurer measuring the air conditioner refrigerant pressure.

5. The apparatus of claim 1, wherein: the controller provides the operation signal to the fan motor and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure for the measurement time, when a compressor is operated and a vehicle speed is 0.

6. The apparatus of claim 1, wherein: the controller turns off a compressor when the intake air temperature is not present within the predetermined temperature, and operates the cooling fan when a coolant temperature is greater than or equal to a reference temperature in a state in which the controller turns off an air conditioner switch.

7. A method for controlling a cooling fan of a vehicle, comprising: confirming, by a controller, an ignition-off time for which an ignition was turned off when the ignition is turned on; deciding, by the controller, whether or not the ignition-off time exceeds a decision-possible time; deciding, by the controller, whether or not an intake air temperature is present within a predetermined temperature when the ignition-off time exceeds the decision-possible time; and locking a fan motor, by the controller, depending on a change rate of an air conditioner refrigerant pressure for a measurement time when the intake air temperature is present within the predetermined temperature.

8. The method of claim 7, wherein the locking of the fan motor includes: confirming a first change rate of the air conditioner refrigerant pressure for a first measurement time; operating the cooling fan for a second measurement time; confirming a second change rate of the air conditioner refrigerant pressure for the second measurement time; and stopping the operation of the cooling fan depending on the first change rate and the second change rate.

9. The method of claim 8, wherein the stopping of the operation of the cooling fan depending on the first change rate and the second change rate includes: calculating a comparison value on the basis of the first change rate and the second change rate; deciding whether or not the comparison value is less than or equal to a decision reference; deciding whether or not the comparison value is maintained for a duration in a state in which the comparison value is less than or equal to the decision reference; and stopping the operation of the cooling fan in the case in which the comparison value is not maintained for the duration.

10. The method of claim 9, wherein the comparison value is calculated through an equation:
C=B/A where C is the comparison value, A is the first change rate, and B is the second change rate.

11. The method of claim 7, wherein the locking of the fan motor depending on the change rate of the air conditioner refrigerant pressure for the measurement time when the intake air temperature is present within the predetermined temperature includes: deciding whether or not a compressor is operated when the intake air temperature is present within the predetermined temperature; deciding whether or not a vehicle speed is 0 when the compressor is operated; and locking the fan motor depending on the change rate of the air conditioner refrigerant pressure for the measurement time when the vehicle speed is 0.

12. The method of claim 7, wherein the deciding of whether or not the intake air temperature is present within the predetermined temperature includes: deciding whether or not the intake air temperature is less than a maximum temperature; and deciding whether or not the intake air temperature is greater than or equal to a minimum temperature when the intake air temperature is less than the maximum temperature.

13. The method of claim 7, wherein, after the deciding of whether or not the intake air temperature is present within the predetermined temperature, further comprising: turning off a compressor when the intake air temperature is not present within the predetermined temperature; measuring a coolant temperature in a state in which an air conditioner switch is turned off; and operating the cooling fan when the coolant temperature is greater than or equal to a reference temperature.

14. A non-transitory computer readable medium containing program instructions executed by a processor, the computer readable medium comprising: program instructions that confirm an ignition-off time for which an ignition was turned off when the ignition is turned on; program instructions that decide whether or not the ignition-off time exceeds a decision-possible time; program instructions that decide whether or not an intake air temperature is present within a predetermined temperature when the ignition-off time exceeds the decision-possible time; and program instructions that lock a fan motor depending on a change rate of an air conditioner refrigerant pressure for a measurement time when the intake air temperature is present within the predetermined temperature.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2015-0167950 filed in the Korean Intellectual Property Office on Nov. 27, 2015, the entire contents of which are incorporated herein by reference.

BACKGROUND

(a) Technical Field

The present invention relates to an apparatus for controlling a cooling fan of a vehicle, and more particularly, to an apparatus and a method for controlling the cooling fan capable of preventing damage to a fan motor by locking the fan motor in cold weather conditions, such as winter.

(b) Description of the Related Art

Since a large amount of heat is generated in an engine of a vehicle, a coolant is circulated in the vicinity of the engine in order to cool the engine, thereby lowering the temperature of the engine. A heated coolant is heat-radiated in a radiator, and a cooling fan is installed in an engine compartment of the vehicle in order to improve a heat radiation effect of the radiator.

The cooling fan maintains a temperature of the coolant in an appropriate condition to prevent overheat of the engine and allow performance of the engine to be optimized. The cooling fan is primarily driven by a motor.

In cold weather conditions, moisture or snow is introduced into the cooling fan, such that freezing of the cooling fan often occurs. Therefore, at the time of the freezing of the cooling fan, the cooling fan is not operated even in a condition in which the cooling fan is turned on.

In such conditions, the cooling fan is not generally operated. However, when a driver presses a defrost button in order to remove fog or frost, an air conditioner is operated, such that an air conditioner refrigerant pressure gradually rises. When the air conditioner refrigerant pressure reaches a predetermined pressure, it arrives at a region in which the cooling fan should be operated. However, the cooling fan is not operated due to locking of the motor caused by the freezing of the cooling fan. In addition, when a locking time becomes long, the motor may be damaged or, in extreme circumstances, a fire may occur in the engine compartment.

When an external temperature sensor is present in the vehicle, it is possible that the cooling fan is not operated at sub-zero temperatures. However, when an external temperature sensor is not mounted in the vehicle, an external temperature may not be checked, such that a control may not be performed to prevent operation of the cooling fan at sub-zero temperatures. In addition, in such a case, the cooling fan is operated in a predetermined condition, such that the cooling fan may be frozen, thereby causing damage to the motor. The damage to the motor generates overheat of the engine, which can result in significant repair costs.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY

The present invention provides an apparatus and a method for controlling a cooling fan of a vehicle capable of locking a fan motor on the basis of an intake air temperature and an air conditioner refrigerant pressure in order to prevent damage to the fan motor in cold weather conditions.

Further, the present invention provides an apparatus and a method for controlling a cooling fan of a vehicle capable of operating the cooling fan in the case in which a coolant temperature is greater than or equal to a reference temperature.

An exemplary embodiment of the present invention provides an apparatus for controlling a cooling fan of a vehicle, the cooling fan being installed in an engine compartment of the vehicle, including: a fan motor driving the cooling fan; and a controller generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor, wherein the controller confirms an ignition-off time for which an ignition was turned off when the ignition is turned on, confirms a change rate of an air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and an intake air temperature is present within a predetermined temperature, and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure.

The confirm a first change rate of the air conditioner refrigerant pressure for a first measurement time, operate the cooling fan through the fan motor by providing the operation signal to the fan motor for a second measurement time, confirm a second change rate of the air conditioner refrigerant pressure for the second measurement time, and stop the operation of the cooling fan depending on the first change rate and the second change rate.

The controller may calculate a comparison value on the basis of the first change rate and the second change rate, decide whether or not the comparison value is less than or equal to a decision reference, and stop the operation of the cooling fan in the case in which the comparison value is not maintained for a duration in a state in which the comparison value is less than or equal to the decision reference.

The apparatus for controlling a cooling fan of a vehicle may further include: a state detector including at least one of an intake air temperature measurer measuring the intake air temperature; a coolant measurer measuring a coolant temperature; a speed measurer measuring a vehicle speed; and a pressure measurer measuring the air conditioner refrigerant pressure.

The controller may provide the operation signal to the fan motor and lock the fan motor depending on the change rate of the air conditioner refrigerant pressure for the measurement time, when a compressor is operated and a vehicle speed is 0.

The controller may turn off a compressor when the intake air temperature is not present within the predetermined temperature, and operate the cooling fan when a coolant temperature is greater than or equal to a reference temperature in a state in which the controller turns off an air conditioner switch.

Another exemplary embodiment of the present invention provides a method for controlling a cooling fan of a vehicle by an apparatus for controlling a cooling fan of a vehicle, including: confirming an ignition-off time for which an ignition was turned off when the ignition is turned on; deciding whether or not the ignition-off time exceeds a decision-possible time; deciding whether or not an intake air temperature is present within a predetermined temperature when the ignition-off time exceeds the decision-possible time; and locking a fan motor depending on a change rate of an air conditioner refrigerant pressure for a measurement time when the intake air temperature is present within the predetermined temperature.

In an exemplary embodiment of the present invention, it is possible to prevent the fan motor from freezing in cold weather conditions, such as winter, and thus prevent damage by stopping operation of the fan motor.

In addition, in the case in which the coolant temperature is greater than or equal to the reference temperature, the cooling fan is operated, thereby making it possible to prevent overheat of the engine.

Other effects that may be obtained or are predicted by an exemplary embodiment of the present invention will be explicitly or implicitly described in a detailed description of the present invention. That is, various effects that are predicted according to an exemplary embodiment of the present invention will be described in the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 2 is a flow chart showing a method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention.

FIG. 3 is an illustrative view showing a control method when an air conditioner switch is turned off in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention.

FIG. 4 is a flow chart showing a method for detecting locking in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention.

FIG. 5 is an illustrative view for describing the method for detecting locking in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention.

FIG. 6 is an illustrative view for describing a first change rate and a second change rate in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms “unit”, “-er”, “-or”, and “module” described in the specification mean units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof.

Further, the control logic of the present invention may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN).

Hereinafter, an operation principle of an apparatus and a method for controlling a cooling fan of a vehicle according to an exemplary embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

However, drawings provided below and a detailed description to be provided below relate to one preferred exemplary embodiment of several exemplary embodiments for effectively describing features of the present invention. Therefore, the present invention is not limited to only the following drawings and description.

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

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

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

The state detector 100 detects information required in order to control the cooling fan 160. The state detector 100 includes an intake air temperature measurer 102, a speed measurer 104, a pressure measurer 106, and a coolant temperature measurer 108.

The intake air temperature measurer 102 measures an intake air temperature, which is a temperature of air introduced into the vehicle, and provides the measured temperature to the controller.

The speed measurer 104 measure a vehicle speed, which is a speed of the vehicle, and provides the measured vehicle speed to the controller.

The pressure measurer 106 measures an air conditioner refrigerant pressure, and provides the measured air conditioner refrigerant pressure to the controller.

The coolant temperature measurer 108 measures a coolant temperature of an engine, and provides the measured coolant temperature to the controller.

The controller 110 controls at least one of the state detector 100, the air conditioner switch 120, the compressor 125, the relay 130, the connector 140, the blower assembly 150, and the cooling fan 160, which are components of the apparatus 50 for controlling a cooling fan of a vehicle, in order to operate or stop the cooling fan 160.

The controller 110 confirms an ignition-off time for which an ignition was turned off when the ignition is turned on. The controller 110 confirms a change rate of the air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and the intake air temperature is present within a predetermined temperature. The controller 110 performs a control to lock or normally operate a fan motor 157 depending on the change rate of the air conditioner refrigerant pressure. A method for controlling the cooling fan 160 in the controller 110 will be described in more detail with reference to FIGS. 2 to 5.

For this purpose, the controller 110 may be implemented by at least one processor operated by a predetermined program, which may be programmed to perform the respective steps of a method for controlling a cooling fan of a vehicle according to an exemplary embodiment of the present invention.

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

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

The relay 130 provides an operation signal to the connector 140 depending on a control of the controller 110.

The connector 140 receives the operation signal from the relay 130 to drive the fan motor 157. To this end, the connector 140 includes a high speed connector 143, a low speed connector 146, and a ground connector 149. The high speed connector 143 is directly connected to the fan motor 157, and the low speed connector 146 is connected to the fan motor 157 through a resistor 153. The ground connector 149 is connected to the fan motor 157 and a ground. Here, the high speed connector 143, the low speed connector 146, and the ground connector 149 may also be formed of a switch. The connector 140 drives the fan motor 157 through the low speed connector 146 and the resistor 153 when it receives a low speed operation signal from the relay 130. In addition, the connector 140 drives the fan motor 157 through the high speed connector 143 when it receives a high speed operation signal from the relay 130.

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

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

The resistor 153 adjusts a speed of the fan motor 157. That is, the larger the resistance value of the resistor 153, the lower the speed at which the fan motor 157 is driven.

The cooling fan 160 is driven by the fan motor 157 included in the blower assembly 150. The cooling fan 160 maintains a temperature of a coolant in an appropriate condition to prevent overheat of the engine and allow performance of the engine to be optimally exhibited.

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

FIG. 2 is a flow chart showing a method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the controller 110 confirms whether or not the ignition is turned on (S210). Here, the controller 110 may confirm whether or not the ignition is turned on by receiving an ignition-on signal from an initial detector (not shown).

The controller 110 confirms the ignition-off time for which the ignition was turned off (S215). That is, the controller 110 may confirm the ignition-off time by counting a time for which the ignition was turned off before the ignition is turned on.

The controller 110 decides whether or not the ignition-off time exceeds the decision-possible time (S220). Here, the decision-possible time may indicate a reference time for deciding that the vehicle is parked in the night, and may be set by a worker or be set through a predefined algorithm (for example, a program or a probability model). For example, the decision-possible time may be six hours.

The reason for deciding whether or not the ignition-off time exceeds the decision-possible time as described above is to confirm that the vehicle was parked in the night. In the case in which the vehicle is parked in the night, it may be assumed that an intake air temperature and an external air temperature are the same as each other. Therefore, damage to the fan motor 157 may be prevented using the intake air temperature without using an external air temperature sensor.

The controller 110 confirms the intake air temperature (S225) when the ignition-off time exceeds the decision-possible time. Here, the intake air temperature may be a temperature measured through the intake air temperature measurer when the ignition of the vehicle is turned off.

The controller 110 decides whether or not the intake air temperature is present within a predetermined temperature (S230). That is, the controller 110 may decide whether or not the intake air temperature is less than or equal to a maximum temperature, and greater than or equal to a minimum temperature. Here, the maximum temperature and the minimum temperature indicate reference temperatures for deciding a temperature at which the cooling fan 160 may be frozen, and may be set by a worker or be set through a predefined algorithm (for example, a program or a probability model). For example, the maximum temperature may be 7° C., and the minimum temperature may be −10° C.

The controller 110 decides whether or not the compressor 125 is operated (S235) when the intake air temperature is present within the predetermined temperature. That is, the controller 110 may decide whether the compressor 125 is in a turn-on state or a turn-off state when the intake air temperature is greater than or equal to the minimum temperature and is less than or equal to the maximum temperature.

The controller 110 decides whether or not a vehicle speed is 0 (S240) when the compressor 125 is operated. That is, the controller 110 confirms the vehicle speed provided from the speed measurer when the compressor 125 is operated. The controller 110 decides whether or not the vehicle speed is 0 to decide whether or not the vehicle is in an idle state. In addition, the controller 110 generates an operation signal for operating the cooling fan 160 when the vehicle speed is 0. Here, the operation signal may be a low speed operation signal for operating the cooling fan 160 at a low speed.

The controller 110 performs locking detection for whether to lock or normally operate the fan motor 157 (S245). A method for detecting locking of the fan motor will be described in detail with reference to FIG. 4.

The controller 110 decides whether or not a locking detection result is normal (S250).

The controller 110 stops an operation of the cooling fan 160 (S255) when the locking detection result is not normal. That is, the controller 110 stops the operation of the cooling fan 160 and stops an operation of the compressor 125 when the locking detection result is locking.

Meanwhile, the controller 110 moves to S275 to operate the cooling fan 160, when the locking detection result is normal. Here, since a method for controlling the cooling fan 160 that is normal is the same as or similar to a method for controlling the cooling fan 160 that is generally used, a detailed description therefor will be omitted.

The controller 110 confirms whether or not the ignition is turned off (S260). That is, the controller 110 may complete the control of the cooling fan when the ignition is turned off.

Meanwhile, the controller 110 confirms the immediately previous state of the cooling fan (S265) when the ignition-off time is less than or equal to the decision-possible time. That is, since the controller 110 may decide that the vehicle is not parked in the night when the ignition-off time is less than or equal to the decision-possible time, a state of the cooling fan 160 that was decided by previously turning on the ignition is confirmed.

The controller 110 decides whether or not the immediately previous state of the cooling fan is normal (S270).

The controller 110 operates the cooling fan 160 (S275) when the immediately previous state of the cooling fan is normal. In addition, the controller 110 may normally drive the cooling fan 160 since it is not severe cold when the intake air temperature exceeds the maximum temperature. Then, the controller 110 may confirm that the ignition is turned off.

Meanwhile, the controller 110 turns off the compressor 125 (S280) when the intake air temperature is less than the minimum temperature.

The controller 110 turns off the air conditioner switch 120 (S285) when the compressor 125 is not operated as a confirmation result in S235, the vehicle speed is not 0 as a decision result in S240, or the controller 110 turns off the compressor 125 in S280.

The controller 110 confirms a coolant temperature (S290). That is, the controller 110 receives the coolant temperature provided from the coolant temperature measurer 108 in order to control the cooling fan 160 and confirms the received coolant temperature, when the air conditioner switch 120 is turned off. The controller 110 decides whether or not the coolant temperature is greater than or equal to a reference temperature.

The controller 110 operates the cooling fan 160 (S295) when the coolant temperature is greater than or equal to the reference temperature. That is, the controller 110 may lower a temperature of the engine by operating the cooling fan 160 when the coolant temperature is greater than or equal to the reference temperature, in order to prevent overheat of the engine. Here, the reference temperature indicates a reference temperature for deciding whether or not the overheat is generated 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 the operation signal to the fan motor 157 through the relay 130 and the connector 140, and operates the cooling fan 160 through the fan motor 157. Here, the operation signal is a high speed operation signal 320. Therefore, the cooling fan 160 is operated at a high speed, thereby making it possible to lower the temperature of the engine.

FIG. 4 is a flow chart showing a method for detecting locking in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention, FIG. 5 is an illustrative view for describing the method for detecting locking in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention, and FIG. 6 is an illustrative view for describing a first change rate and a second change rate in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention.

Referring to FIGS. 4 to 6, the controller 110 confirms a first change rate of the air conditioner refrigerant pressure for a first measurement time (S410). Here, the first measurement time may indicate a time delayed when the operation signal is transmitted from the controller 110 to the fan motor 157 through the relay 130 and the connector 140. The reason for delaying and then transmitting the operation signal in the controller 110 as described above is to prevent bugs from being generated in the relay 130, the connector 140, and the like. Here, as shown in FIG. 5, the first measurement time 510 may be a time from 0 second to a first time. For example, the first time may be 0.5 second.

In other words, the controller 110 receives a first air conditioner refrigerant pressure provided from the pressure measurer 106 at 0 second, and receives a second air conditioner refrigerant pressure provided from the pressure measurer 106 at the first time. The controller 110 calculates the first change rate on the basis of the first air conditioner refrigerant pressure and the second air conditioner refrigerant pressure. Here, the first change rate may be represented by a gradient 610, as shown in FIG. 6.

The controller 110 operates the cooling fan 160 for a second measurement time (S420). In other words, the controller 110 provides the operation signal to the relay 130 at the first time, and the relay 130 provides the operation signal to the connector 140. Here, the operation signal may be a low speed operation signal. The low speed connector 146 of the connector 140 drives the fan motor 157 through the resistor 153 when the low speed operation signal is received. Therefore, the cooling fan 160 may be operated by the fan motor 157.

Here, as shown in FIG. 5, the second measurement time 530 may indicate a time for which the cooling fan 160 is operated, and may be a predetermined value. The second measurement time 530 may be a time from the first time to a 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(S430).

The controller 110 confirms a second change rate of the air conditioner refrigerant pressure for the second measurement time (S440). In other words, the controller 110 receives a third air conditioner refrigerant pressure provided from the pressure measurer 106 at the first time, and receives a fourth air conditioner refrigerant pressure provided from the pressure measurer 106 at the second time. The controller 110 calculates the second change rate on the basis of the third air conditioner refrigerant pressure and the fourth air conditioner refrigerant pressure. Here, the second change rate may be represented by a gradient 630, as shown in FIG. 6.

The controller 110 decides whether or not a total measurement time exceeds a reference time (S450). That is, the controller 110 adds the first measurement time and the second measurement time to each other to generate the total measurement time, and decides whether or not the total measurement time exceeds the reference time.

The controller 110 decides whether or not a comparison value is less than or equal to a decision reference (S460). In detail, the controller 110 calculates the comparison value on the basis of the first change rate and the second change rate. That is, the controller 110 may calculate the comparison value through equation 1.


C=B/A [equation 1]

Here, C may indicate the comparison value, A may indicate the first change rate, and B may indicate the second change rate.

The controller 110 decides whether or not the comparison value is less than or equal to the decision reference (S460). Here, the decision reference is a reference value for deciding whether to normally operate the fan motor 157 or lock the fan motor 157. For example, the decision reference may be 0.7.

The controller 110 decides whether or not the comparison value is maintained for a duration in a state in which the comparison value is less than or equal to the decision reference (S470). For example, the duration may be 2 seconds.

The controller 110 decides that the cooling fan 160 is normal (S480) when the comparison value is maintained for the duration in the state in which the comparison value is less than or equal to the decision reference.

The controller 110 decides that the fan motor 157 is locked (S490) in the case in which the comparison value exceeds the decision reference or the comparison value is not maintained for the duration in the state in which the comparison value is less than or equal to the decision reference.

As described above, the apparatus 50 for controlling a cooling fan of a vehicle according to an exemplary embodiment of the present invention decides whether or not cold weather conditions (e.g., winter) are present on the basis of the intake air temperature of air introduced from the outside into the vehicle when the ignition-off time exceeds the decision-possible time. In cold weather conditions, the apparatus 50 for controlling the cooling fan confirms the change rate of the air conditioner refrigerant pressure to lock the fan motor 157, thereby making it possible to prevent damage to the fan motor.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.





 
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