KR20060110554A - A method and apparatus for cooling fan rpm control for heavy equipment - Google Patents

Abstract

An apparatus and a method for controlling cooling fan RPM for heavy construction equipment are provided to actively control cooling fan RPM in accordance with the variation of work environment or work condition. An apparatus for cooling a cooling fan RPM for heavy construction equipment, comprises a cooling fan driving pump(170) for driving a cooling fan(140); a cooling fan driving motor(172) driven by the pump; a controller(150) for controlling cooling fan RPM; and a cooling fan RPM control valve(176) arranged at one side of a hydraulic line(174) for interconnecting the pump and the motor. The cooling fan RPM control valve varies the preset pressure of the hydraulic line in proportion to the current value output from the controller and applied to a pilot pressure chamber(180). A cooling fan RPM coefficient is determined by the maximum value of an engine coolant temperature coefficient of an engine(102), a working oil temperature coefficient of an actuator, a charge air temperature coefficient of an air cooler(130), and an air conditioner operating coefficient of an air conditioner. The current value and optimum cooling fan RPM are determined by the cooling fan RPM coefficient.

Description

Cooling fan speed control device and control method for construction equipment {A method and apparatus for cooling fan rpm control for heavy equipment}

1 is a schematic diagram showing a configuration of a cooling apparatus of a heavy construction equipment according to the prior art.

Figure 2 is a schematic diagram showing the configuration of the cooling fan speed control apparatus of heavy equipment according to a preferred embodiment of the present invention.

3 is a graph showing a functional relationship between an engine coolant temperature coefficient K _ENG of an engine and an actual temperature value T _ENG of an engine coolant according to the present invention.

4 is a graph showing a functional relationship between the charge air temperature coefficient K _CAC of the air cooler and the actual temperature value T _CAC of the charge air according to the present invention.

5 is a graph showing the functional relationship between the hydraulic oil temperature coefficient (K _H ) of the actuator according to the present invention and the actual temperature value (T _H ) of the hydraulic oil.

Figure 6 is a graph showing the characteristics of the air conditioning operating coefficient (K _AIRCON ) according to the operation of the air conditioner according to the present invention.

7 is a graph showing a functional relationship between an output current value Current according to the present invention and the cooling fan rotation speed coefficient K _f .

8 is a graph showing a functional relationship between a cooling fan speed (Fan rpm) and the cooling fan speed coefficient (K _f ) according to the present invention.

9 is a flowchart illustrating a control method of the cooling fan speed according to the present invention.

** Description of Codes for Major Configurations of Drawings **

102: engine 104: engine controller

110: radiator 112: engine coolant temperature detection means

120: oil cooler 122: hydraulic oil temperature detection means

130: charge air cooler 132: charge air temperature detection means

140: cooling fan 150: control unit

160: heat exchanger 170: pump for driving the cooling fan

172: cooling fan drive motor 174: hydraulic line

176: cooling fan speed control valve 178: cavitation prevention valve

180: pilot pressure chamber

The present invention relates to a cooling fan speed control device and a control method of the construction equipment, more specifically, a radiator for preventing the engine from overheating, an oil cooler for preventing the operating oil of various actuators from overheating, combustion sucked into the engine Compared with the coefficients determined by the internal algorithm, the actual temperature values respectively detected from the charge air cooler that cools the temperature of the air and the heat exchanger for adjusting the air inside the cab are output to the relief valve to output the current value to the relief valve. The present invention relates to a cooling fan rotation speed control device and a control method of a heavy construction equipment that actively controls rotation speed according to working conditions and working environment.

In general, heavy construction equipment such as excavators are essentially provided with a cooling device for preventing overheating of the engine and hydraulic fluid in case the engine or the hydraulic oil is overheated due to work and running.

As shown in FIG. 1, the cooling device includes an engine 2, a blower-type cooling fan 10 installed at one side of the engine 2, the cooling fan driving pump 20, and the cooling. A cooling fan driving motor 30 for operating the fan driving pump 20, a radiator 40 installed in front of the cooling fan 10 to cool the engine coolant, and the cooling fan 10. It is configured to include an oil cooler 50 installed in the front to cool the hydraulic oil.

Meanwhile, a relief valve 62 is installed in parallel in the hydraulic line 60 connecting the cooling fan driving motor 30 and the cooling fan driving pump 20, and the relief valve 62 is the hydraulic pressure. A function of limiting the maximum pressure of the hydraulic oil supplied from the cooling fan driving motor 30 to the cooling fan driving pump 20 through the line 60 is performed.

Such a conventional cooling device is irrelevant to the coolant state of the radiator 40 and the hydraulic oil state of the hydraulic machine, and is driven only by the rotation speed of the engine 2, so that the cooling environment of the radiator 40 may be changed. By not actively controlling the rotation speed of the cooling fan, the efficiency of the cooling device is not only degraded, but there is a problem in that fuel consumption is unnecessary.

Therefore, the present invention is derived to solve the problems of the prior art as described above, the object of the present invention is to cool the heavy construction equipment that can control the rotational speed of the cooling fan in accordance with the working environment and working conditions appropriately It is to provide a fan speed control device and a control method.

According to a feature of the present invention for achieving the object as described above, the present invention is an engine, a radiator for cooling the cooling water of the engine, an oil cooler for cooling the operating oil of various actuators, and combustion air sucked into the engine In order to cool the charge air cooler for reducing exhaust gas by reducing the temperature of the engine, the heat exchanger of the outdoor unit installed on one side of the engine for air conditioning in the cab, the engine radiator, the oil cooler, the charge air cooler and the heat exchanger. A cooling device for heavy construction equipment consisting of a cooling fan 140 for generating wind, comprising: a cooling fan driving pump for driving the cooling fan, a cooling fan driving motor driven by the pump, and rotation of the cooling fan. The control unit for controlling the number and is installed on one side of the hydraulic line connecting the pump and the motor, the control unit The output current value is output to the pilot pressure chamber is configured to include a cooling fan speed control valve which can vary the set pressure of the hydraulic line proportionally, the engine coolant temperature coefficient of the engine 102 ( K _ENG ), the operating oil temperature coefficient (K _H ) of the actuator, the charge air temperature coefficient (K _CAC ) of the air cooler 130 and the cooling fan rotation according to the maximum value of the air conditioning operating coefficient (K _AIRCON ) of the air conditioner The number coefficient K _f is determined, and the output current value and the optimal cooling fan speed value are determined by the cooling fan speed coefficient K _f .

Engine coolant temperature detection means installed on one side of the radiator to detect the coolant temperature of the engine, hydraulic oil temperature detection means installed on one side of the oil cooler to detect the hydraulic oil temperature of various actuators, and installed on one side of the charge air cooler It further comprises a charge air temperature detecting means for detecting the temperature of the charge air.

The actual temperature value T _ENG of the engine coolant detected from the temperature detecting means of the engine coolant is directly proportional to the engine coolant temperature coefficient K _ENG , and the engine coolant temperature coefficient K _ENG is equal to "0". "1" is determined between the engine actual temperature value of the cooling water (T _ENG) is the engine cooling water thermometer at 80 ℃ to 90 ℃ (K _ENG) to the engine cooling water thermometer at about 100 ℃ to gradually begins to increase (K _ENG Keeps the maximum value.

The hydraulic oil actual temperature value T _H detected from the hydraulic oil temperature detection means of various actuators is directly proportional to the hydraulic oil temperature coefficient K _H , and the hydraulic oil temperature coefficient K _H is between "0" and "1". It is determined that the actual temperature value of the hydraulic fluid (T _H ) starts to increase gradually around 60 ℃ oil temperature coefficient (K _H ), the hydraulic oil temperature coefficient (K _H ) maintains the maximum value around 90 ℃.

The charge air actual temperature value T _CAC detected from the charge air temperature detection means of the charge air cooler is directly proportional to the charge air temperature coefficient K _CAC , and the charge air temperature coefficient K _CAC is “0. "and" 1 "is determined between the actual temperature value of the charge-air (T _CAC) is 40 ℃ to take up at 50 ℃ be air thermometer (K _CAC) to the air thermometer occupies from 70 ℃ before and after gradually begins to increase ( K _CAC ) maintains the maximum value.

For efficient control of the air conditioner, the optimum value is selected so that the air conditioner operating coefficient (K _AIRCON ) does not become constant, that is, less than 0.5, when the cooling fan is rotated above a certain speed (ON). OFF The air conditioner operating coefficient (K _AIRCON ) is selected as zero.

According to another feature of the invention, the step of calculating the charge air temperature coefficient (K _CAC ) of the air cooler by receiving the actual temperature value (T _CAC ) of the charge air from the charge air temperature detection means of the air cooler, the engine of the engine Calculating the engine coolant temperature coefficient (K _ENG ) of the engine by receiving the actual temperature value (T _ENG ) of the engine coolant from the coolant temperature detection means, and the actual temperature value (T _H) of the hydraulic oil from the hydraulic oil detection means of various actuators. Calculating the hydraulic oil temperature coefficient K _H of the various actuators, determining whether the air conditioner is ON or OFF, and determining that the air conditioner is ON. calculating a work coefficient (K _AIRCON), the air conditioner non-operating (OFF) when it is determined that the air conditioning operation of the step coefficient charge-air temperature and the air cooler to calculate (K _AIRCON) to "0" Number (K _CAC), the engine cooling water temperature coefficient of the engine (K _ENG), number of the working oil temperature coefficient of the various actuators (K _H) and the number of the rotation the greater the maximum cooling fan of the air conditioning operation coefficient (K _AIRCON) of the air conditioner coefficient (K _f) to the decision step, and a cooling-fan speed coefficients (K _f) and the cooling fan properly set in accordance with the revolution speed functional relationship between the output current value (current) is applied to the control valve to the model, and the cooling of Calculating the output current value (Current) to be applied to the cooling fan speed control valve by substituting the fan speed coefficient (K _f ) into the function relation, and cooling fan speed (Fan rpm) according to the output current value. It is configured to include the step of controlling.

The charge air temperature coefficient K _CAC of the air cooler, the engine coolant temperature coefficient K _ENG of the engine, and the actual oil temperature T _H of various actuators are determined between "0" and "1".

The air conditioner operating coefficient K _AIRCON of the air conditioner is determined between "0.5" and "1".

Engine Coolant Temperature (K _ENG) and the actual temperature value of the engine coolant of the engine (T _ENG) is in a proportional relationship, the engine actual cooling water temperature value (T _ENG) the engine cooling water thermometer in a 80 ℃ to 90 ℃ (K _ENG ) starts to increase gradually, and the engine coolant temperature coefficient (K _ENG ) maintains the maximum value around 100 ° C.

The charge air temperature coefficient K _CAC of the air cooler and the actual temperature value T _{CAC of} the charge air are directly proportional to each other, and the actual temperature value T _CAC of the charge air is 40 ° C. to 50 ° C. The number of K _CAC starts to increase, and the charge air temperature coefficient K _CAC maintains the maximum value around 70 ° C.

The hydraulic oil temperature coefficient K _H of the various actuators and the actual temperature value T _{H of} the hydraulic oil are directly proportional to each other, and when the actual temperature value T _H of the hydraulic oil is about 60 ° C., the hydraulic oil temperature coefficient K _H is The fluid temperature coefficient (K _H ) maintains its maximum value at around 90 ° C.

According to the cooling fan rotation speed control device and control method of the construction equipment according to the present invention having such a configuration, it is possible to automatically control the rotation speed of the cooling fan in response to changes in the working environment or working conditions, etc. There is this.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the cooling fan speed control device and control method of the heavy equipment according to the invention having the configuration as described above will be described in detail.

As shown in FIG. 2, the cooling device according to the present invention includes an engine cooler, a radiator 110 for cooling the coolant of the engine 102, and an oil cooler for cooling hydraulic oil of various actuators (not shown). 120 and the charge air cooler 130 for reducing the exhaust gas by reducing the temperature of the combustion air sucked into the engine 102 in accordance with the strengthening exhaust gas regulation as the problem of environmental pollution has recently emerged, and the Control unit 150 for controlling the rotation speed of the cooling fan 140 and the cooling fan 140 for generating wind to cool the engine 102, radiator 110, oil cooler 120 and the charge air cooler 130 It consists of

 Therefore, a blower type cooling fan 140 is installed between the engine 102 and the radiator 110 to rotate by a fan belt (not shown) of the engine 102, and drives the cooling fan 140. The outside air sucked into the engine compartment through the inlet grill is cooled while passing through the radiator 110 and the oil cooler 120 or the charge air cooler 130, and then released into the atmosphere through the outlet grill.

In addition, the heavy equipment may be further provided with an air conditioner for maintaining the air in the cab in the most suitable state according to the purpose. The heat exchanger of the indoor unit is installed inside the cab, but the heat exchanger 160 of the outdoor unit is installed in the engine room so as to be heat-exchanged by the forced air of the cooling fan 140. Therefore, the refrigerant compressed by a compressor (not shown) driven by the power of the engine 102 flows into the condenser, is heat-exchanged by forced air of the cooling fan, and flows back into the compressor through an evaporator. Repeat the process to keep the air in the cab appropriate for your application.

Meanwhile, in order to drive the cooling device, the cooling fan driving pump 170 is connected to the cooling fan driving motor 172 by the hydraulic line 174, and one side of the hydraulic line 174 may change the set pressure. Cooling fan rotation speed control valve 176 is installed, the cavitation prevention valve for preventing the cavitation due to the rotation of the cooling fan drive motor 172 on the other side of the hydraulic line (174) (178) ) Is installed. The cooling fan speed control valve 176 is an electronic proportional control valve or a variable relief valve configured such that one side of the pilot pressure chamber 180 can be variably controlled in proportion to the output current value output from the controller 150. It is composed. Therefore, the relief set pressure of the cooling fan speed control valve 176 is variable in proportion to the output current value of the controller 150.

One side of the radiator 110, the engine coolant temperature detection means 112 for detecting the coolant temperature of the engine is installed, one side of the oil cooler 120 operating oil temperature detection means for detecting the hydraulic oil temperature of the various actuators (122) Is installed, the charge air temperature detecting means 132 for detecting the temperature of the charge air is installed on one side of the charge air cooler 130.

The engine coolant temperature detection unit 112 reports the actual temperature value T _ENG of the engine coolant and the actual temperature value T _CAC of the charge air from the charge air cooler 130, respectively. An engine controller (Engine ECU) 104 that outputs to the controller 150 through a date link is further installed on one side of the engine 102.

Accordingly, the controller 150 receives the actual temperature value T _ENG of the engine coolant and the actual temperature value T _CAC of the charge air from the charge air cooler 130, respectively, in the engine controller 104. The actual temperature value T _H of the hydraulic oil is reported from the oil cooler 120, the operation state of the operation of the air conditioner (ON / OFF) is received, and compared with the reference temperature value set in the controller 150. When the actual temperature value is higher than the reference temperature value, the output current value (Current) proportional thereto is outputted to the pilot pressure chamber 180 of the cooling fan speed control valve 176 to rotate the fan speed 140 (Fan). rpm).

Hereinafter, how to determine the output current value for controlling the rotation speed of the cooling fan 140 will be described in detail.

Preferably, the rotation speed of the cooling fan 140 of the present invention is determined by the following four coefficients. That is, the four coefficients are the engine coolant temperature coefficient K _ENG of the engine 102, the hydraulic oil temperature coefficient K _H of the actuator, the charge air temperature coefficient K _CAC of the air cooler 130, and air conditioning. The air conditioner operating coefficient (K _AIRCON ) of the machine.

3 shows a functional relationship between the engine coolant temperature coefficient K _ENG of the engine 102 and the actual temperature value T _ENG of the engine coolant. According to an embodiment of the invention, the actual temperature value of the engine cooling water (T _ENG) is the engine cooling water thermometer at 80 ℃ to 90 ℃ (K _ENG) to the engine cooling water thermometer at about 100 ℃ to gradually begins to increase (K _ENG ) Maintains the maximum value.

4 shows the relationship between the charge air temperature coefficient K _CAC of the air cooler 130 and the actual temperature value T _CAC of the charge air. According to an embodiment of the present invention, take up the actual temperature value of the air (T _CAC) is occupied can the air thermometer at 40 ℃ to 50 ℃ (K _CAC) gradually begins to increase up before and after the 70 ℃ be air thermometer (K _CAC) Maintains the maximum value.

5 shows a functional relationship between the hydraulic oil temperature coefficient K _H of the actuator and the actual temperature value T _H of the hydraulic oil. According to an embodiment of the invention, the actual temperature value of the fluid (T _H) is 60 ℃ number of working oil thermometer before and after the (K _H) to the working oil thermometer at 90 ℃ to gradually begins to increase (K _H) to maintain the maximum value It has the characteristic to

6 shows a function value indicating the characteristics of the air conditioner operating coefficient K _AIRCON of the air conditioner. According to an embodiment of the present invention, the optimum value is selected so that the air conditioner operating coefficient K _AIRCON does not become a constant value, that is, 0.5 or less at the time of operation (ON) for the efficiency of the air conditioner. Of course, the OFF air conditioner operating coefficient K _AIRCON has a value of zero. Therefore, when the air conditioner is turned on, the rotation speed of the cooling fan 140 rotates at a predetermined speed or more for efficient control of the air conditioner.

As such, the engine coolant temperature coefficient K _ENG of the engine 102, the charge air temperature coefficient K _CAC of the air cooler 130, the hydraulic oil temperature coefficient K _H of the actuator, and the air conditioning operating coefficient of the air conditioner ( K _AIRCON ) must have an appropriate value between 0 and 1 and cannot exceed 1.

Here, in order to control the rotation speed of the cooling fan 140 in an optimal state, in the embodiment of the present invention, the engine coolant temperature coefficient K _ENG of the engine 102 and the charge air temperature coefficient K of the air cooler 130. _CAC ), the maximum value of each of the actuator oil temperature coefficient (K _H ) and the air conditioner operating coefficient (K _AIRCON ) of the air conditioner is determined as the cooling fan rotation coefficient (K _f ).

FIG. 7 shows a functional relationship between an output current value Current and the cooling fan speed factor K _f , and FIG. 8 shows a cooling fan speed Fan rpm and the cooling fan speed factor K _f . It shows a functional relationship.

The cooling fan rotation coefficient (K _f ) and the output current value (Current) are inversely related to each other, and the output current value (Current) and the cooling fan rotation speed (Fan rpm) are inversely related to each other, the cooling fan rotation The number coefficient K _f is directly proportional to the cooling fan rotation speed (Fan rpm). Therefore, when the cooling fan rotational speed coefficient K _f becomes large, the intensity of the output current value decreases, and therefore, the relief pressure of the cooling fan rotational speed control valve 176 becomes high and the rotational speed Fan fan of the cooling fan becomes high. On the contrary, when the cooling fan speed coefficient K _f decreases, the intensity of the output current value increases, and therefore, the relief pressure of the cooling fan speed control valve 176 is lowered, thereby lowering the rotation speed Fan fan of the cooling fan.

Hereinafter, the operation of the cooling fan speed control apparatus of the present invention having the configuration as described above will be described in detail with reference to FIG.

The charge air temperature coefficients K _CAC of the air cooler 130 are received by inputting the actual temperature value T _CAC of the charge air from the charge air temperature detection means 132 of the air cooler 130. "Calculate between (S10).

The engine coolant temperature coefficient K _ENG of the engine 102 is received between "0" and "1" by receiving the actual temperature value T _ENG of the engine coolant from the engine coolant temperature detection means 112 of the engine 102. Calculate in (S20).

The hydraulic oil temperature coefficient T _H of the various actuators is received from the hydraulic oil detecting means 122 of the various actuators and the hydraulic oil temperature coefficient K _H of the various actuators is calculated between “0” and “1” (S30).

It is determined whether the air conditioner is operated (S40), and when it is determined that the air conditioner is operated (ON), the air conditioner operating coefficient K _AIRCON is calculated between "0.5" and "1" (S50). If it is determined that the air conditioner is not operated (OFF), the air conditioner operation coefficient (K _AIRCON ) is calculated as "0" (S60).

The largest maximum of the charge air temperature coefficient (K _CAC ) of the air cooler, the engine coolant temperature coefficient (K _ENG ) of the engine, the hydraulic oil temperature coefficient (K _H ) of the various actuators and the air conditioning operating coefficient (K _AIRCON ) of the air conditioner The value is determined as the cooling fan rotation speed coefficient K _f (S70).

A function relationship between the cooling fan speed coefficient K _f and the output current value Current applied to the cooling fan speed control valve 176 is appropriately set according to the product model as shown in FIG. 7; S80), and calculates an output current value to be applied to the cooling fan speed control valve 176 by substituting the cooling fan speed coefficient K _f into the functional relationship (S90), and as shown in FIG. The cooling fan speed (Fan rpm) is controlled according to the output current value (S100).

Therefore, when the output current value is lowered, the set pressure of the cooling fan speed control valve 176 is increased, and the cooling fan speed (Fan rpm) is increased. Conversely, when the output current value is increased, the set pressure of the cooling fan speed control valve 176 is lowered, and the cooling fan speed (Fan rpm) is reduced.

As described above, according to the configuration of the present invention, the following effects can be expected.

By detecting the operating conditions of the radiator, oil cooler, charge air cooler and heat exchanger and determining the rotation speed of the cooling fan proportionally based on the output current value, it is possible to proactively respond to changes in working environment or working conditions. The rotation speed of the cooling fan is automatically controlled, and therefore, the effect of increasing the cooling efficiency and preventing unnecessary fuel consumption is expected.

Claims (12)

An engine, a radiator for cooling the cooling water of the engine, an oil cooler for cooling the operating oil of various actuators, a charge air cooler for reducing exhaust gas by reducing the temperature of combustion air drawn into the engine, and air in the cab In the cooling device of the heavy construction equipment consisting of a heat exchanger of the outdoor unit installed on one side of the engine for harmonization, a cooling fan 140 for generating wind to cool the engine, radiator, oil cooler, charge air cooler and heat exchanger, A cooling fan driving pump for driving the cooling fan; A cooling fan driving motor driven by the pump, A controller for controlling the rotation speed of the cooling fan; Cooling fan speed control valve is installed on one side of the hydraulic line connecting the pump and the motor, the output current value output from the control unit is applied to the pilot pressure chamber to change the set pressure of the hydraulic line in proportion It is configured to include, The engine coolant temperature coefficient K _ENG of the engine 102, the hydraulic oil temperature coefficient K _H of the actuator, the charge air temperature coefficient K _CAC of the air cooler 130, and the air conditioning operating coefficient of the air conditioner ( The cooling fan speed coefficient K _f is determined by the maximum value of K _AIRCON ), and the output current value and the optimal cooling fan speed value are determined by the cooling fan speed coefficient K _f . Cooling fan speed control device of heavy construction equipment. The method of claim 1, Engine coolant temperature detection means installed on one side of the radiator to detect the coolant temperature of the engine, hydraulic oil temperature detection means installed on one side of the oil cooler to detect the hydraulic oil temperature of various actuators, and installed on one side of the charge air cooler Cooling fan speed control device of the heavy construction equipment, characterized in that it further comprises a charge air temperature detection means for detecting the temperature of the charge air. The method of claim 2, The actual temperature value T _ENG of the engine coolant detected from the temperature detecting means of the engine coolant is directly proportional to the engine coolant temperature coefficient K _ENG , and the engine coolant temperature coefficient K _ENG is equal to "0". "1" is determined between the engine actual temperature value of the cooling water (T _ENG) is the engine cooling water thermometer at 80 ℃ to 90 ℃ (K _ENG) to the engine cooling water thermometer at about 100 ℃ to gradually begins to increase (K _ENG Cooling fan speed control device of the heavy equipment, characterized in that to maintain the maximum value. The method of claim 2, The hydraulic oil actual temperature value T _H detected from the hydraulic oil temperature detection means of various actuators is directly proportional to the hydraulic oil temperature coefficient K _H , and the hydraulic oil temperature coefficient K _H is between "0" and "1". It is determined that the actual temperature value (T _H ) of the hydraulic fluid is characterized by the fact that the hydraulic temperature coefficient (K _H ) gradually increases around 60 ℃, the hydraulic oil temperature coefficient (K _H ) maintains the maximum value around 90 ℃ Cooling fan speed control device of construction equipment. The method of claim 2, The charge air actual temperature value T _CAC detected from the charge air temperature detection means of the charge air cooler is directly proportional to the charge air temperature coefficient K _CAC , and the charge air temperature coefficient K _CAC is “0. "and" 1 "is determined between the actual temperature value of the charge-air (T _CAC) is 40 ℃ to take up at 50 ℃ be air thermometer (K _CAC) to the air thermometer occupies from 70 ℃ before and after gradually begins to increase ( K _CAC ) is a cooling fan speed control device of heavy equipment, characterized in that to maintain the maximum value. The method according to claim 1 or 2, For efficient control of the air conditioner, the optimum value is selected so that the air conditioner operating coefficient (K _AIRCON ) does not become constant, that is, less than 0.5, when the cooling fan is rotated above a certain speed (ON). Cooling fan speed control device for heavy construction equipment, characterized in that the air conditioner operating coefficient (K _AIRCON ) is set to zero. Calculating the charge air temperature coefficient K _CAC of the air cooler by receiving the actual temperature value T _CAC of the charge air from the charge air temperature detection means of the air cooler; Calculating an engine coolant temperature coefficient K _ENG of the engine by receiving an actual temperature value T _ENG of the engine coolant from the engine coolant temperature detection means of the engine; Calculating the hydraulic oil temperature coefficient K _H of the various actuators by receiving the actual temperature value T _H of the hydraulic oil from the hydraulic oil detecting means of the various actuators; Determining whether the air conditioner is operated (ON / OFF); Calculating an air conditioner operation coefficient K _AIRCON when it is determined that the air conditioner is ON; Calculating an air conditioner operating coefficient K _AIRCON as “0” when it is determined that the air conditioner is deactivated (OFF); The largest maximum of the charge air temperature coefficient (K _CAC ) of the air cooler, the engine coolant temperature coefficient (K _ENG ) of the engine, the hydraulic oil temperature coefficient (K _H ) of the various actuators and the air conditioning operating coefficient (K _AIRCON ) of the air conditioner Determining the value as a cooling fan speed coefficient K _f ; The output current value suitably set, and the cooling-fan speed coefficients (K _f) in accordance with the function relationship between the (Current) to a model to be applied to the cooling-fan speed factor (K _f) and the cooling-fan speed control valve Calculating an output current value (Current) to be applied to the cooling fan speed control valve by substituting a functional relationship; Cooling fan speed control method of the heavy construction equipment, characterized in that it comprises a step of controlling the cooling fan speed (Fan rpm) in accordance with the output current value. The method of claim 7, wherein The charge air temperature coefficient K _CAC of the air cooler, the engine coolant temperature coefficient K _ENG of the engine, and the actual oil temperature T _H of various actuators are determined between “0” and “1”. Method for controlling the cooling fan speed of equipment under construction. The method of claim 7, wherein Air conditioner operating coefficient (K _AIRCON ) of the air conditioner is characterized in that the cooling fan speed control method of the heavy equipment of construction, characterized in that determined between "0.5" and "1". The method of claim 7, wherein Engine Coolant Temperature (K _ENG) and the actual temperature value of the engine coolant of the engine (T _ENG) is in a proportional relationship, the engine actual cooling water temperature value (T _ENG) the engine cooling water thermometer in a 80 ℃ to 90 ℃ _(ENG K) is the temperature coefficient engine cooling water at about 100 ℃ to gradually begins to increase (K _ENG) to rotate the cooling fan of the heavy equipment, characterized by maintaining the maximum value control method. The method of claim 7, wherein The charge air temperature coefficient K _CAC of the air cooler and the actual temperature value T _{CAC of} the charge air are directly proportional to each other, and the actual temperature value T _CAC of the charge air is 40 ° C. to 50 ° C. number (K _CAC) gradually begins to increase up to at about 70 ℃ be air thermometer (K _CAC) to rotate the cooling fan of the heavy equipment, characterized by maintaining the maximum value control method. The method of claim 7, wherein The hydraulic oil temperature coefficient K _H of the various actuators and the actual temperature value T _{H of} the hydraulic oil are directly proportional to each other, and when the actual temperature value T _H of the hydraulic oil is about 60 ° C., the hydraulic oil temperature coefficient K _H is A method of controlling the cooling fan speed of heavy equipment in construction, characterized by the fact that the hydraulic oil temperature (K _H ) maintains a maximum value at about 90 ° C.

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