JP6091887B2 - Fan control device - Google Patents

Description

  The technology of the present disclosure relates to a fan control device that controls rotation of a fan that is connected to an output shaft of an engine and sends outside air to a radiator and a condenser.

  2. Description of the Related Art Conventionally, a vehicle engine has been provided with a fan that sends outside air to a radiator through which a coolant that cools the engine circulates. This fan is connected to the output shaft of the engine via an electronically controlled fan clutch, as in Patent Document 1, for example, and the connection state with the output shaft is controlled in accordance with various information related to the operating state of the engine. The The rotational speed of the fan is controlled so as to be closer to the rotational speed of the output shaft as the operating state requires cooling of the coolant.

JP-A-2005-214155

  By the way, in recent years, a vehicle that cools the radiator and the condenser with one fan by disposing a condenser that cools the air-conditioning refrigerant in front of the radiator has also become widespread. When the above-described fan is applied to such a vehicle, even if the cooling is turned on immediately after the cold start of the engine, it is difficult to obtain sufficient cooling performance due to insufficient cooling of the air-conditioning refrigerant.

  An object of the technology of the present disclosure is to provide a fan control device that can suppress insufficient cooling of a refrigerant for air conditioning in a fan control device that controls a fan that cools a radiator and a condenser.

A fan control device that solves the above problems includes an acquisition unit that acquires information about whether or not coolant for cooling an engine is flowing into a radiator, a temperature related to a vehicle interior temperature, a vehicle speed, and an outside air temperature, and the acquisition And a controller that controls rotation of a fan connected to an output shaft of the engine via an electronically controlled fan clutch using information acquired by the engine, and the fan cools the coolant External air is sent to a radiator and a condenser that cools the air-conditioning refrigerant, and the controller is configured to rotate the fan so that the coolant does not flow into the radiator and relates to the vehicle interior temperature. The temperature is equal to or higher than a set temperature, and the vehicle speed is equal to or lower than a set speed, and when the condition is satisfied, the vehicle speed exceeds the set speed. With rotating the fan as the condition is satisfied until a speed greater than zero is selected from the control map the associated for each outside air temperature as said set speed.

According to this configuration, even when the engine does not flow into the radiator and the vehicle speed is equal to or lower than the set speed, the fan rotates if the temperature related to the vehicle interior temperature is equal to or higher than the set temperature. The outside air is sent to the condenser. As a result, insufficient cooling of the air conditioning refrigerant can be suppressed even immediately after the cold start of the engine.
Further, after the condition is established, the fan rotates until the vehicle speed exceeds the set speed. That is, the fan rotates at least during the period from when the engine starts to when the vehicle starts. As a result, the lack of cooling of the air-conditioning refrigerant during the period is suppressed with a high probability.

In this fan control device, the acquisition unit acquires the temperature of the cooling liquid, and the control unit includes a temperature of the cooling liquid and a thermostat that allows the cooling liquid to flow into the radiator in a valve-open state. It is preferable to compare with the valve opening temperature and determine that the cooling liquid does not flow into the radiator when the temperature of the cooling liquid is equal to or lower than the valve opening temperature.

  According to this configuration, if the temperature related to the vehicle interior temperature is equal to or higher than the set temperature and the vehicle speed is equal to or lower than the set speed, the fan rotates as long as the temperature of the coolant does not exceed the valve opening temperature of the thermostat. As a result, insufficient cooling of the air-conditioning refrigerant can be suppressed even when the engine is warmed up.

In this fan control device, it is preferable that the temperature relating to the vehicle interior temperature is an outside air temperature.
Even if the in-vehicle temperature is the same, the higher the outside air temperature, the higher the possibility that the cooling will be used immediately after boarding, and the lower the outside air temperature, the lower the possibility that the cooling will be used immediately after boarding. That is, in predicting the use frequency of cooling, it is preferable to use the outside air temperature as an index rather than the inside temperature. According to the above configuration, since the fan rotates using the outside air temperature as one index, the engine output required for the rotation of the fan can be effectively used.

The functional block diagram which functionally shows the fan control apparatus in this indication with the engine provided with the fan used as control object. The flowchart which shows the process sequence of the fan drive process which a fan control apparatus performs.

Hereinafter, with reference to FIG.1 and FIG.2, one Embodiment of the fan control apparatus in this indication is described.
As shown in FIG. 1, the engine 11 and the radiator 12 are connected to each other by a flow path 13 through which a coolant that cools the engine 11 flows. A thermostat 14 that opens when the coolant temperature Tc, which is the temperature of the coolant, exceeds the valve opening temperature Tvth, is disposed upstream of the radiator 12 in the flow path 13. In addition, a pump 16 connected to the thermostat 14 by the bypass flow path 15 is disposed on the downstream side of the radiator 12 in the flow path 13 while supplying the coolant to the engine 11. The coolant is supplied to the engine 11 by the pump 16 to cool the engine 11. The temperature rises as the engine 11 is cooled, and then flows into the thermostat 14.

  When the coolant temperature Tc is equal to or lower than the valve opening temperature Tvth, the coolant flowing into the thermostat 14 is sent to the pump 16 through the bypass channel 15 without opening the thermostat 14. On the other hand, when the coolant temperature Tc exceeds the valve opening temperature Tvth, the thermostat 14 is opened and sent to the pump 16 through the radiator 12. The valve opening temperature Tvth of the thermostat 14 is a temperature that is estimated to be the completion of warming up of the engine 11, and is set to 82 ° C. in this embodiment.

  A condenser 17 that cools the air-conditioning refrigerant compressed by a compressor (not shown) is disposed on the opposite side of the engine 11 with respect to the radiator 12. On the other hand, on the engine 11 side with respect to the radiator 12, a fan 19 connected to the output shaft 11a of the engine 11 via an electronically controlled fan clutch 18 is disposed. The connection and disconnection of the fan clutch 18 are PWM controlled (Pulse Width Modulation) by a fan control device 20 (hereinafter simply referred to as the control device 20). And while the fan 19 and the output shaft 11a of the engine 11 are connected, the rotational force of the output shaft 11a is transmitted to the fan 19, and the fan 19 rotates with the output shaft 11a. As the fan 19 rotates, outside air is sent to the condenser 17, and outside air that has passed through the condenser 17 is sent to the radiator 12.

  The control device 20 is configured by a CPU (not shown), a ROM storing various control programs and various data, a RAM storing various data temporarily, and the like, and performs various processes based on the various control programs stored in the ROM. Run.

  The input unit 21 of the control device 20 has a signal indicating the coolant temperature Tc from the coolant temperature sensor 31, a signal indicating the outside air temperature Ta from the outside air temperature sensor 32, a signal indicating the vehicle speed V of the vehicle from the vehicle speed sensor 33, and the like. A signal is input at a predetermined control cycle. Further, the input unit 21 includes a signal indicating the fuel injection amount Qf from the fuel injection control unit 34, a signal indicating the accelerator opening degree Ac from the accelerator opening sensor 35, a signal indicating the engine rotation speed Ne from the engine rotation speed sensor 36, These signals are input at a predetermined control cycle. The control device 20 grasps the driving state of the vehicle based on these signals, and executes a fan driving process for controlling the rotation of the fan 19 according to the grasped driving state.

  The main control unit 22 of the control device 20 acquires the various types of information described above through the input unit 21 as an acquisition unit. When the predetermined conditions based on the coolant temperature Tc, the outside air temperature Ta, and the vehicle speed V are satisfied, the main control unit 22 determines that the operation state of the vehicle is in an air conditioning priority state that prioritizes cooling of the air conditioning refrigerant. . And the main control part 22 performs the air-conditioning priority process which controls the fan 19 to the rotational speed according to the air-conditioning priority state.

On the other hand, when the predetermined condition is not satisfied, the main control unit 22 determines that the driving state of the vehicle is in a fuel consumption priority state that prioritizes fuel consumption. And the main control part 22 performs the fuel consumption priority process which controls the fan 19 to the rotational speed according to the fuel consumption priority state. In the fuel efficiency priority process, the main control unit 22 determines the vehicle operating state based on the coolant temperature Tc, the vehicle speed V, the fuel injection amount Qf, the accelerator opening degree Ac, and the engine rotational speed Ne acquired through the input unit 21 as follows. The fan clutch 18 is controlled after selecting from the three operating states shown in FIG.
・ Normal state where the coolant temperature rise is relatively small ・ High load state where the coolant temperature rise is relatively large ・ Starting acceleration state where the vehicle is starting or accelerating

  In the storage unit 23 of the control device 20, a control map in which a drive ratio R that is a ratio of the fan rotation speed FS to the engine rotation speed Ne is defined is stored for each operation state.

  The air-conditioning priority map 24 corresponding to the air-conditioning priority state defines a drive ratio R (= 100%) indicating that the fan 19 and the output shaft 11a are maintained in a connected state so that cooling of the condenser 17 is prioritized. Yes.

  In the normal map 25 corresponding to the normal state and the high load map 26 corresponding to the high load state, a drive ratio R is defined for each coolant temperature Tc. In the normal map 25 and the high load map 26, the drive ratio R (= 0) indicating that the fan 19 and the output shaft 11a are maintained in the disconnected state in the range where the coolant temperature Tc is lower than the valve opening temperature Tvth of the thermostat 14. %). The normal map 25 and the high load map 26 define a drive ratio R that increases stepwise as the coolant temperature Tc rises in a range where the coolant temperature Tc is equal to or higher than the valve opening temperature Tvth. In the high load map 26, a drive ratio R that is equal to or higher than the drive ratio R defined in the normal map 25 is defined for the same coolant temperature Tc.

  The start acceleration map 27 corresponding to the start acceleration state defines a drive ratio R (= 0%) indicating that the fan 19 and the output shaft 11a are maintained in a disconnected state in order to give priority to vehicle acceleration. .

  The main control unit 22 selects a control map corresponding to the driving state of the vehicle from the storage unit 23, and selects the drive ratio R based on the selected control map. Then, the main control unit 22 calculates a target rotation speed TFS that is a target value of the fan rotation speed FS based on the drive ratio R and the engine rotation speed Ne selected by the main control unit 22, and the calculated target The rotational speed TFS is output to the PWM control unit 28.

  In addition to the target rotation speed TFS, the PWM control unit 28 receives a signal indicating the current rotation speed of the fan 19 from the fan rotation speed sensor 37 at a predetermined control cycle. The PWM control unit 28 calculates a duty ratio by feedback control based on the current rotation speed of the fan 19 and the target rotation speed TFS, and outputs a drive signal based on the calculated duty ratio to the fan clutch 18.

With reference to FIG. 2, a processing procedure of the fan drive processing executed by the control device 20 will be described. This fan driving process is repeatedly executed.
First, in step S11, the main control unit 22 acquires various information including the coolant temperature Tc, the outside air temperature Ta, the vehicle speed V, the fuel injection amount Qf, the accelerator opening degree Ac, and the engine speed Ne through the input unit 21. .

  In the next step S12, the main controller 22 compares the valve opening temperature Tvth of the thermostat 14, for example, 82 ° C. with the coolant temperature Tc, and determines whether or not the coolant temperature Tc is equal to or lower than the valve opening temperature Tvth. to decide.

  When the coolant temperature Tc is equal to or lower than the valve opening temperature Tvth (step S11: YES), the main control unit 22 compares the preset temperature Tath, for example, 20 ° C. with the outside air temperature Ta to determine the outside air temperature. It is determined whether Ta is equal to or higher than the set temperature Tath (step S13).

  When the outside air temperature Ta is equal to or higher than the set temperature Tath (step S13: YES), the main control unit 22 compares the preset set speed Vth, for example, 0 km / h with the vehicle speed V, and the vehicle speed V is set. It is determined whether or not the speed is equal to or less than Vth (step S14).

When the vehicle speed V is equal to or lower than the set speed Vth (step S14: YES), the main control unit 22 determines that the driving state of the vehicle is in the air conditioning priority state, and executes the air conditioning priority process (step S15). . That is, the control device 20 executes the air conditioning priority process when the following conditions 1, 2, and 3 are satisfied.
(Condition 1) Coolant does not flow into the radiator 12.
(Condition 2) The outside air temperature Ta is equal to or higher than the set temperature Tath.
(Condition 3) The vehicle speed V is equal to or lower than the set speed Vth.

  In the air conditioning priority process of step S15, the main control unit 22 selects the air conditioning priority map 24 as a control map, thereby maintaining the fan 19 and the output shaft 11a in the connected state at a drive ratio R = 100% and the fan clutch 18. Drive.

  In the next step S16, the main control unit 22 again acquires various information including the vehicle speed V through the input unit 21, and proceeds to the process of step S14. That is, the main control unit 22 continues to execute the air conditioning priority process until the vehicle speed V exceeding the set speed Vth is acquired in the process of step S16.

  On the other hand, when the coolant temperature Tc exceeds the valve opening temperature Tvth (step S12: NO), when the outside air temperature Ta is lower than the set temperature Tath (step S13: NO), the vehicle speed V exceeds the set speed Vth. If so (step S14: NO), the main control unit 22 executes the process of step S17. In step S17, the main control unit 22 determines that the driving state of the vehicle is in the fuel consumption priority state, and executes the fuel consumption priority process.

  In the fuel efficiency priority process of step S17, the main control unit 22 selects the driving state of the vehicle from the normal state, the high load state, and the start acceleration state based on the latest various information. Then, the main control unit 22 drives the fan clutch 18 at a drive ratio R selected based on the control map corresponding to the selected operating state and the coolant temperature Tc, and ends the series of processes.

Next, the operation of the above-described fan control device 20 will be described.
The control device 20 described above drives the fan 19 to send outside air to the condenser 17 when the above conditions 1 to 3 are satisfied. That is, the control device 20 drives the fan 19 if the condition 2 and the condition 3 are satisfied even if the condition 1 in which the fan 19 is not driven is satisfied in the normal map 25 and the high load map 26. Therefore, even if the cooling is used immediately after the engine 11 is started, particularly immediately after the engine 11 is cold started, if the outside air temperature Ta is equal to or higher than the set temperature Tath, the cooling performance of the air conditioning refrigerant can be suppressed. Can be prevented from decreasing.

  Moreover, the control device that controls the air conditioner is generally a control device different from the control device 20. And the control apparatus 20 rotates the fan 19 when the said conditions 1-3 are satisfied. That is, the control device 20 drives the fan 19 independently of the control device that controls the air conditioner. Therefore, since it is not necessary to electrically connect the control device 20 that controls the air conditioner and the control device 20, the fan control system is not complicated in order to suppress insufficient cooling of the air conditioning refrigerant.

  Further, in the control device 20, since the fan 19 rotates even when the coolant temperature Tc is equal to or lower than the valve opening temperature Tvth of the thermostat 14, the cooling of the air conditioning refrigerant is suppressed from being insufficiently cooled even when the engine 11 is warmed up.

  Here, in the condition 2, it is also possible to condition the vehicle interior temperature Ti instead of the outside air temperature Ta. However, even if the in-vehicle temperature Ti is the same, the higher the outside air temperature Ta, the higher the possibility that the cooling will be used immediately after boarding, and the lower the outside air temperature Ta, the lower the possibility that the cooling will be used immediately after boarding. Become. Therefore, in predicting the cooling use frequency, it is preferable to use the outside air temperature Ta as an index rather than the inside temperature Ti. That is, by setting the outside air temperature Ta as one of the execution conditions of the air conditioning priority process, the engine output required for the rotation of the fan 19 can be effectively used.

  By the way, when the vehicle is traveling, the condenser 17 is cooled by the traveling wind. Therefore, even if the conditions 1 and 2 are satisfied, insufficient cooling of the air-conditioning refrigerant may be sufficiently suppressed only by cooling with the traveling wind. Even if the fan 19 is rotated in such a case, the amount of fuel consumption is increased by the amount of rotation of the fan 19.

  In this regard, in the control device 20, since the set speed Vth is 0 km / h, the fan 19 is driven only when the condenser 17 is not cooled by the traveling wind. As a result, it is possible to suppress an increase in fuel consumption accompanying driving of the fan 19 while suppressing insufficient cooling of the air conditioning refrigerant.

  Further, in the fan drive process, the fan 19 and the output shaft 11a are continuously connected unless the vehicle speed V exceeding the set speed Vth is acquired in the re-acquisition of various information (step S16). That is, if the conditions 1 to 3 are satisfied, the fan 19 rotates at least during the period from the start of the engine 11 to the start of the vehicle. Therefore, the lack of cooling of the air-conditioning refrigerant during the period is suppressed with a high probability.

As described above, according to the fan control device 20 of the present embodiment, the effects listed below can be obtained.
(1) Since the fan 19 is driven when the conditions 1 to 3 are satisfied, insufficient cooling of the air-conditioning refrigerant is suppressed even when the engine 11 is cold started.

  (2) The control device 20 drives the fan 19 independently of the control device that controls the air conditioner. Therefore, the fan control system is not complicated in order to suppress insufficient cooling of the air conditioning refrigerant.

(3) Since the fan 19 rotates even when the coolant temperature Tc is equal to or lower than the valve opening temperature Tvth, insufficient cooling of the air conditioning refrigerant is suppressed even when the engine 11 is warmed up.
(4) Since the outside air temperature Ta is set as one of the conditions under which the air conditioning priority process is executed, the engine output required for the rotation of the fan 19 is effectively used to suppress insufficient cooling of the air conditioning refrigerant. It becomes easy to be done.

(5) Since the set speed Vth is 0 km / h, it is possible to suppress an increase in fuel consumption accompanying driving of the fan 19 while suppressing insufficient cooling of the air conditioning refrigerant.
(6) Insufficient cooling of the air-conditioning refrigerant during the period from the start of the engine 11 to the start of the vehicle is suppressed with a high probability.

(7) In the air conditioning priority process, since the fan 19 and the output shaft 11a are continuously connected, insufficient cooling of the air conditioning refrigerant is efficiently suppressed.
In addition, the said embodiment can also be suitably changed and implemented as follows.
In the fan driving process, after the process of acquiring various information again (step S16), the process may proceed to step S12. That is, the air-conditioning priority process may be continued when the re-acquired various information satisfies all of the conditions 1 to 3.

  In the air conditioning priority process, the fan 19 and the output shaft 11a are connected with the drive ratio R according to the situation at that time, not limited to the mode in which the fan 19 and the output shaft 11a are connected at the drive ratio R = 100%. May be. For example, a control map for air conditioning priority processing in which different drive ratios R are defined may be stored in the storage unit 23, and the control maps may be selected according to the outside air temperature Ta. According to such a configuration, over-rotation of the fan 19 in suppressing insufficient cooling of the air-conditioning refrigerant can be suppressed. That is, an increase in fuel consumption due to the rotation of the fan 19 is suppressed.

In condition 3, the set speed Vth is not limited to a speed that is regarded as a stopped state such as 0 km / h, and may be a vehicle speed immediately after starting, such as 5 km / h or 10 km / h.
Moreover, it is preferable that the set speed Vth is a speed at which the insufficient cooling of the air-conditioning refrigerant is resolved by the traveling wind. Therefore, for example, the configuration may be such that the set speed Vth is selected according to the outside air temperature Ta by storing in the storage unit 23 a control map in which the set speed Vth is associated with each outside air temperature Ta. .

  The temperature related to the vehicle interior temperature is not limited to the outside air temperature Ta, but may be the vehicle interior temperature Ti, or may be a temperature based on the outside air temperature Ta and the vehicle interior temperature Ti.

  The condition 1 only needs to be that the coolant does not flow into the radiator 12, and the detection method is not limited to the coolant temperature Tc. For example, when an electronically controlled thermostat is used, the inflow of the coolant to the radiator 12 may be determined based on an open / close signal for the thermostat. Further, for example, when a flow rate sensor for measuring the flow rate of the coolant with respect to the radiator 12 is mounted, the inflow of the coolant to the radiator 12 may be determined based on a detection signal of the flow rate sensor.

  DESCRIPTION OF SYMBOLS 11 ... Engine, 11a ... Output shaft, 12 ... Radiator, 13 ... Flow path, 14 ... Thermostat, 15 ... Bypass flow path, 16 ... Pump, 17 ... Condenser, 18 ... Fan clutch, 19 ... Fan, 20 ... Fan control device , 21 ... input section, 22 ... main control section, 23 ... storage section, 24 ... air conditioning priority map, 25 ... map, 26 ... high load map, 27 ... start acceleration map, 28 ... PWM control section, 31 ... coolant temperature Sensors: 32 ... Outside air temperature sensor, 33 ... Vehicle speed sensor, 34 ... Fuel injection control unit, 35 ... Accelerator opening sensor, 36 ... Engine speed sensor, 37 ... Fan speed sensor.

Claims (3)

An acquisition unit that acquires information about whether or not coolant for cooling the engine flows into the radiator, a temperature related to the interior temperature, a vehicle speed, and an outside air temperature ;
A controller for controlling rotation of a fan connected to the output shaft of the engine via an electronically controlled fan clutch using the information acquired by the acquisition unit;
The fan sends outside air to a radiator that cools the coolant and a condenser that cools the refrigerant for air conditioning.
As a condition for rotating the fan, the control unit may
The coolant does not flow into the radiator, and
The temperature related to the vehicle interior temperature is equal to or higher than a set temperature; and
The vehicle speed is equal to or lower than a set speed;
When the condition is satisfied, the fan is rotated as the condition is satisfied until the vehicle speed exceeds the set speed, and a speed greater than 0 corresponds to the outside air temperature as the set speed. A fan control device that selects the set speed from the attached control map . The acquisition unit acquires the temperature of the coolant,
The control unit compares the temperature of the coolant with a valve opening temperature of a thermostat that allows the coolant to flow into the radiator when the valve is open, and the temperature of the coolant is equal to or lower than the valve opening temperature. The fan control device according to claim 1, wherein it is determined that the coolant does not flow into the radiator. Fan controller according to claim 1 or 2 temperature for the interior temperature is ambient temperature.

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