JP2013047470A - Fan control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fan control device capable of improving fuel economy while keeping a temperature of an engine within a prescribed range.SOLUTION: The fan control device 20 estimates an operation state of a vehicle from a normal state, a high-load state and an acceleration and deceleration state on the basis of a temperature of an engine cooling liquid inputted via an input part 21, a fuel injection amount, a vehicle speed, an acceleration opening, and an engine rotation speed. Then, the fan control device selects a map corresponding to the operation state which is estimated from a normal map 24a in which a drive amount of the fan 14 with respect to the temperature of the engine cooling liquid is specified, a high-load map 24b, and an acceleration and deceleration map 24c. Then, the fan control device selects the drive amount of the fan 14 from the map corresponding to the estimated operation state on the basis of the temperature of the engine cooling liquid, and operates a target value of the rotation speed of the fan 14.

Description

  The present invention relates to a fan control device that controls the rotational speed of a fan that rotates according to the output of an engine.

  2. Description of the Related Art Conventionally, in a vehicle engine, a fan is generally connected to an output shaft of the engine via a fan clutch in order to increase the cooling efficiency of engine coolant. In such a fan, if the fan is normally operated until cooling of the engine coolant is unnecessary, not only the engine output loss will be increased, but also the temperature of the engine coolant will be excessively lowered, preventing improvement of fuel consumption. It becomes. Therefore, in order to solve such a problem, a fan clutch control method as described in Patent Document 1, for example, has been proposed for the above-described fan control device that controls the rotational speed of the fan.

  In the fan clutch control method described in Patent Document 1, thresholds are set for the engine coolant temperature and the engine oil temperature, and the fan clutch is connected and disconnected depending on whether the measured value of each temperature exceeds the threshold value. Is controlled. According to such a control method, since the fan is driven when the temperature of the engine coolant or the temperature of the engine oil exceeds a threshold value, loss of engine output is suppressed, and each of the engine coolant and the engine oil has a predetermined temperature. It becomes easy to be maintained in range.

JP 2005-3131 A

  On the other hand, the change in the temperature of the engine coolant and the change in the temperature of the engine oil often differ greatly depending on the driving state of the vehicle. In this regard, in the fan clutch control method as described above, since the connection and disconnection of the fan clutch are switched based on the threshold value of the temperature, for example, even when the temperature rises rapidly, the temperature does not become excessively high. In addition, in the predetermined temperature range, the temperature threshold is inevitably set to the low temperature side. Therefore, when the temperature does not increase rapidly, the fan may be driven at a rotational speed higher than required for the engine coolant temperature and the engine oil temperature, thereby improving fuel consumption. There was still room for improvement.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a fan control device capable of improving fuel efficiency while keeping the temperature of an engine within a predetermined range.

  One aspect of the present invention is a fan control device that controls rotation of a fan for cooling a vehicle engine, the driving state estimation unit for estimating the driving state of the vehicle, the temperature of the engine coolant, A storage unit that stores a control map in which the driving amount of the fan is associated with each operation state, the control map corresponding to the operation state estimated by the operation state estimation unit, and the temperature of the engine coolant A rotation speed calculation unit that calculates a rotation speed of the fan from the start, acceleration state, a start / acceleration state in which the vehicle is starting and accelerating, and a temperature of the engine coolant. Any one of a high load state in which the increase is relatively large and a normal state in which the temperature rise in the engine coolant is relatively small is estimated.

  According to one aspect of the present invention, the rotational speed of the fan is set from the control map for each driving state of the vehicle and the temperature of the engine coolant. As a result, it is possible to rotate the fan at a rotational speed commensurate with an increase in the temperature of the engine coolant. Therefore, compared with the case where the fan is driven at a rotational speed higher than the rotational speed required for cooling the engine, the engine output loss due to the driving of the fan is suppressed, and the engine temperature is kept within a predetermined range. It is possible to improve the fuel consumption while maintaining it. In addition, the engine coolant is easily maintained at a high temperature and the engine oil is also easily maintained at a high temperature as compared with the case where the fan is driven at a rotational speed higher than the rotational speed required for cooling the engine. It is also possible to suppress engine output loss due to engine friction.

  Further, in the above-described start / acceleration state where the vehicle starts and accelerates, the temperature of the engine coolant is often sufficiently lower than in other driving states. On the other hand, since such a start / acceleration state is normally in a low speed and high load state, if the driving state is simply estimated according to the load state, even for such a start / acceleration state, The same control map as in the high load state is used. In this regard, in the above-described aspect, separate control maps are used for the start / acceleration state and the high load state. Therefore, the above-described effect becomes more remarkable.

  In one aspect of the present invention, the storage unit includes a high load map that is the control map corresponding to the high load state, a normal map that is the control map corresponding to the normal state, and the start / A start / acceleration map, which is the control map corresponding to the acceleration state, is stored, and the driving amount of the fan is associated with the high load map in a range where the temperature of the engine coolant is equal to or higher than a first set temperature. The normal map is associated with the drive amount of the fan in a range where the temperature of the engine coolant is equal to or higher than a second set temperature higher than the first set temperature.

  According to one aspect of the present invention, in a high load state in which the temperature increase of the engine coolant is relatively large, the engine coolant temperature is higher than in a normal state in which the temperature increase of the engine coolant is relatively small. The fan is driven from a low temperature state. As a result, engine cooling in a high load state and improvement in fuel efficiency in a normal state can be realized with higher probability.

According to one aspect of the present invention, the start / acceleration map corresponds to the same temperature in the fan stop or the high load map and the normal map in the entire range of the temperature of the engine coolant. A drive amount equal to or less than the attached drive amount is set.
In the driving state where the vehicle is starting and accelerating, the temperature of the engine coolant is often sufficiently lower than in other driving states, and it is also an operating state in which engine output is particularly required. . In this regard, according to one aspect of the present invention, in such a start-up / acceleration state, the fan is stopped, or the rotation of the fan is suppressed more than in other operation states, so that the fuel consumption is improved. In addition to being achieved, the loss of engine output due to the drive of the fan is reduced, so it is possible to suppress a reduction in the acceleration performance of the vehicle.

One of the aspects of the present invention is that the operation state estimation unit has a condition that the temperature of the engine coolant is lower than a predetermined temperature when the start / acceleration state is estimated.
According to one aspect of the present invention, the start / acceleration state is estimated on the condition that the temperature of the engine coolant is lower than the predetermined temperature, so that the temperature of the engine coolant is equal to or higher than the predetermined temperature. If so, even if other conditions are satisfied, the driving state is not estimated as the start / acceleration state. As a result, in the start / acceleration map, even if a driving amount is set at which the fan is stopped or the rotation of the fan is suppressed as compared with other operating states, the engine coolant can be stopped or the fan can be prevented from rotating. It is possible to more reliably suppress an excessive increase.

In one aspect of the present invention, the driving state estimation unit estimates the driving state based on the temperature of the engine coolant, the fuel injection amount, the vehicle speed, the accelerator opening, and the engine rotation speed.
According to one aspect of the present invention, the operating state is estimated based on the temperature of the engine coolant, the fuel injection amount, the vehicle speed, the accelerator opening, and the engine rotation speed. Therefore, compared with the mode in which the driving state is estimated by the parameter selected from these parameters, the accuracy regarding the estimation result of the driving state is increased.

The functional block diagram which shows the fan control apparatus in one Embodiment of this invention functionally with the engine provided with the fan used as control object. The graph which shows the mode of the setting of the normal map which the fan control apparatus of the embodiment employ | adopts. The graph which shows the aspect of the setting of the high load map which the fan control apparatus of the embodiment employ | adopts. The flowchart which shows the process sequence of the driving | running state estimation process which the fan control apparatus of the embodiment performs.

Hereinafter, an embodiment embodying a fan control device of the present invention will be described with reference to FIGS.
[Configuration of fan control unit]
As shown in FIG. 1, a fan 14 connected to an output shaft 11 a of the engine 11 via an electronically controlled fan clutch 13 is disposed between the engine 11 and the radiator 12. The connection and disconnection of the fan clutch 13 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 14 and the output shaft 11a of the engine 11 are connected, the rotational force of the output shaft 11a is transmitted to the fan 14, and the fan 14 rotates with the output shaft 11a.

  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.

  A detection signal indicating the current temperature T of the engine coolant (hereinafter referred to as coolant temperature T) is input from the temperature detection sensor 31 to the input unit 21 of the control device 20, and a detection signal indicating the fuel injection amount Q is input. Is input from the fuel injection amount sensor 32 at a predetermined control cycle. Further, a detection signal indicating the accelerator opening degree Ac is input from the accelerator opening degree sensor 33 to the input unit 21, and a detection signal indicating the vehicle speed v of the vehicle on which the engine 11 is mounted is input from the vehicle speed sensor 34. Furthermore, a detection signal indicating the engine speed Ne is input from the engine speed sensor 35 at a predetermined control cycle.

  The main control unit 22 of the control device 20 constitutes an operation state estimation unit, and the coolant temperature T, the fuel injection amount Q, the accelerator opening degree Ac, the vehicle speed v, the engine speed Ne, and the like input to the input unit 21 Based on the five pieces of information, a driving state estimation process for estimating the driving state of the vehicle is executed. Note that the main control unit 22 estimates which of the following three driving states the driving state of the vehicle is.

-Normal state where the engine coolant temperature rise is relatively small-High load state where the engine coolant temperature rise is relatively large-Start or acceleration where the engine is running Acceleration state The storage unit 23 of the control device 20 includes a control map in which the drive ratio R that is the ratio of the fan rotation speed FS that is the rotation speed of the fan 14 to the engine rotation speed Ne and the coolant temperature T is associated with the above-described control map. Each of the three operating states is stored separately. That is, the storage unit 23 stores a normal map 24a corresponding to the normal state, a high load map 24b corresponding to the high load state, and a start / acceleration map 24c corresponding to the start / acceleration state. The drive ratio R set in the control map is a value based on the fan rotation speed FS of the fan 14 when the engine coolant reaches the target temperature, and the operation state described above based on various experimental results and simulation results. This is a value defined for each engine speed Ne.

  As shown in FIG. 2, in the normal map 24a, six different drive ratios R in each of the following six temperature ranges so that the drive ratio R increases stepwise as the coolant temperature T increases. Is set.

Coolant temperature T is less than 90 ° C., which is the second set temperature: Drive ratio R = 0.0%
Coolant temperature T is 90 ° C. or higher and lower than 92 ° C .: Drive ratio R = 32.5%
Coolant temperature T is 92 ° C. or higher and lower than 94 ° C .: Drive ratio R = 45.0%
Coolant temperature T is 94 ° C. or higher and lower than 95 ° C .: Drive ratio R = 60.0%
Coolant temperature T is 95 ° C. or higher and lower than 96 ° C .: Drive ratio R = 90.0%
Coolant temperature T is 96 ° C or higher: Drive ratio R = 100%
As shown in FIG. 3, in the high load map 24b, the five different drive ratios R have the following five temperatures so that the drive ratio R also increases stepwise as the coolant temperature T increases. Set for each of the ranges. Further, in the high load map 24b, the coolant temperature T at which the drive ratio R is greater than 0.0% is lower than that in the normal map 24a, and at the same coolant temperature T, the same drive ratio R as in the normal map 24a. Alternatively, a drive ratio R higher than that of the normal map 24a is set.

Coolant temperature T is less than 89 ° C. which is the first set temperature: drive ratio R = 0.0%
Coolant temperature T is 89 ° C. or higher and lower than 91 ° C .: Drive ratio R = 35.0%
Coolant temperature T is 91 ° C. or higher and lower than 93 ° C .: Drive ratio R = 50.0%
Coolant temperature T is 93 ° C. or higher and lower than 95 ° C .: Drive ratio R = 60.0%
Coolant temperature T is 95 ° C. or higher and lower than 96 ° C .: Drive ratio R = 90.0%
Coolant temperature T is 96 ° C or higher: Drive ratio R = 100%
In the start / acceleration map 24c, the drive ratio R is set to 0.0% regardless of the coolant temperature T.

  The main control unit 22 of the control device 20 selects the drive ratio R as a drive amount selection unit based on the control map of the operation state selected in the operation state estimation process and the coolant temperature T. 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 as a rotation speed calculation unit. Then, the calculated target rotational speed TFS is output to the PWM control unit 25.

  In addition to the target rotational speed TFS, a detection signal indicating the current rotational speed of the fan 14 is input to the PWM control unit 25 at a predetermined control cycle. The PWM control unit 25 calculates a duty ratio by feedback control based on the current rotation speed of the fan 14 and the target rotation speed TFS, and outputs a drive signal based on the calculated duty ratio to the fan clutch 13.

[Operation of fan control unit]
Next, the process procedure of the driving | running state estimation process which the control apparatus 20 performs is demonstrated with reference to FIG. The driving state estimation process is a process for estimating which of the three driving states described above, and is repeatedly executed every predetermined control cycle.

  First, the main control unit 22 compares a first set vehicle speed v1, for example, 20 km / h, with a vehicle speed v, and determines whether or not the vehicle speed v is equal to or higher than the first set vehicle speed v1 (step S11). ). When it is determined that the vehicle speed v is less than the first set vehicle speed v1 (step S11: NO), the main control unit 22 sets a preset first set opening Ac1, for example, 10% and the accelerator opening Ac. In comparison, it is determined whether or not the accelerator opening degree Ac is equal to or greater than the first set opening degree Ac1 (step S12).

  When it is determined that the accelerator opening degree Ac is equal to or greater than the first set opening degree Ac1 (step S12: YES), the main control unit 22 sets the preset third set temperature T3, for example, 93 ° C. and the coolant temperature T. To determine whether the coolant temperature T is equal to or lower than the third set temperature T3 (step S13). When it is determined that the coolant temperature T is equal to or lower than the third set temperature T3 (step S13: YES), the main control unit 22 estimates that the driving state of the vehicle is the start / acceleration state (step S14). Then, a series of processing is completed.

Thus, the main control unit 22 estimates that the vehicle is starting when the following conditions 1 to 3 are satisfied, that is, the driving state is the above-described start / acceleration state.
(Condition 1) The vehicle speed v is less than the first set vehicle speed v1.
(Condition 2) The accelerator opening Ac is equal to or greater than the first set opening Ac1.
(Condition 3) The coolant temperature T is equal to or lower than the third set temperature T3.
On the other hand, when it is determined that the vehicle speed v is equal to or higher than the first set vehicle speed v1 (step S11: YES), and when the accelerator opening Ac is determined to be less than the first set opening Ac1 in step S12 ( Step S12: NO), the main control unit 22 advances the process of Step S15. That is, the main control unit 22 compares a preset rotational speed Ne1, for example, 1300 rpm, with the engine rotational speed Ne, and determines whether or not the engine rotational speed Ne is equal to or lower than the set rotational speed Ne1.

  When it is determined that the engine rotational speed Ne is greater than the set rotational speed Ne1 (step S15: NO), the main control unit 22 sets a second set vehicle speed v2 that is set in advance higher than the first set vehicle speed v1, for example, 50 km / h is compared with the vehicle speed v, and it is determined whether or not the vehicle speed v is equal to or lower than the second set vehicle speed v2 (step S16). When it is determined that the vehicle speed v is equal to or lower than the second set vehicle speed v2 (step S16: YES), the main control unit 22 sets a preset second set opening Ac2, for example, 70% and the accelerator opening Ac. In comparison, it is determined whether or not the accelerator opening degree Ac is equal to or smaller than the second set opening degree Ac2 (step S17). When it is determined that the accelerator opening degree Ac is equal to or less than the second set opening degree Ac2 (step S17: YES), the main control unit 22 advances the process of step S13.

Thus, the main control unit 22 estimates that the vehicle is accelerating when the following conditions 4 to 7 are satisfied, that is, the driving state is the above-described start / acceleration state.
(Condition 4) The engine rotational speed Ne is higher than the set rotational speed Ne1.
(Condition 5) The vehicle speed v is equal to or lower than the second set vehicle speed v2.
(Condition 6) The accelerator opening Ac is equal to or less than the second set opening Ac2.
(Condition 7) The coolant temperature T is equal to or lower than the third set temperature T3.
On the other hand, when it is determined that the engine rotational speed Ne is equal to or lower than the set rotational speed Ne1 (step S15: YES), or when it is determined in step S16 that the vehicle speed v is greater than the second set vehicle speed v2 (step S16). : NO), the main controller 22 advances the process of step S18. Further, when it is determined in step S17 that the accelerator opening degree Ac is larger than the second set opening degree Ac2, or when it is determined in step S13 that the coolant temperature T is larger than the third set temperature T3. (Step S13: NO), the main control unit 22 advances the process of Step S18.

  In step S18, the main control unit 22 compares a preset injection amount Q1, for example, 10 cc / sec, with the fuel injection amount Q, and the state where the fuel injection amount Q is equal to or greater than the set injection amount Q1 is a fixed period. It is determined whether or not FP, for example, continues for 10 seconds or more. When it is determined that the state of the set injection amount Q1 or more continues for a certain period of time FP (step S18: YES), the main control unit 22 compares the vehicle speed v with the first set vehicle speed v1, and the vehicle speed v is It is determined whether or not the vehicle speed is equal to or higher than the first set vehicle speed v1 (step S19).

  When it is determined that the vehicle speed v is equal to or higher than the first set vehicle speed v1 (step S19: YES), the main control unit 22 sets a second set temperature T2 that is set in advance lower than the third set temperature T3, for example, 89 ° C. And the coolant temperature T are compared to determine whether the coolant temperature T is equal to or higher than the second set temperature T2 (step S20). When it is determined that the coolant temperature T is equal to or higher than the second set temperature T2 (step S20: YES), the main control unit 22 estimates the driving state of the vehicle as a high load state (step S21) and continues. Terminate the process.

  On the other hand, when it is determined that the state where the fuel injection amount is equal to or greater than the set injection amount Q1 has not been continued for a certain period of time FP (step S18: NO), it is determined in step S19 that the vehicle speed v is less than the first set vehicle speed v1. If it is found (step S19: NO), the main control unit 22 advances the process of step S22. In step S22, the main control unit 22 determines whether or not the increase width ΔT of the coolant temperature T in the fixed period FP is a preset increase increase ΔT1, for example, 2 ° C. or more.

  When it is determined that the increase width ΔT is equal to or greater than the set increase width ΔT1 (step S22: YES), the main control unit 22 advances the process of step S20. When it is determined that the temperature increase width ΔT is less than the set increase width ΔT1 (step S22: NO), and when the coolant temperature T is less than the first set temperature T1 in step S20 (step S20: NO), the main control unit 22 estimates the driving state of the vehicle as a normal state and ends the series of processes (step S23).

  As described above, the main control unit 22 satisfies the following conditions 8 to 10 or satisfies the following conditions 8 and 9 when the above conditions 1 to 3 are not satisfied and the above conditions 4 to 7 are not satisfied. Assuming that the following conditions 10 and 11 are satisfied, the operating state is estimated to be the high load state. For example, the state in which the coolant temperature T becomes equal to or higher than the first set temperature T1 when the fuel is continuously supplied, the state where the increase ΔT is large during low-speed traveling with the fuel continuously supplied, A state in which the increase width ΔT is large although the fuel is not continuously supplied is estimated as a high load state. And the main control part 22 estimates the driving | running state which does not belong to the said start / acceleration state and the said high load state based on the said conditions 1-condition 11 as a normal state.

(Condition 8) The state in which the fuel injection amount Q is equal to or greater than the set injection amount Q1 continues for a certain period of time FP.
(Condition 9) The vehicle speed v is equal to or higher than the first set vehicle speed v1.
(Condition 10) The coolant temperature T is equal to or higher than the first set temperature T1.
(Condition 11) The increase width ΔT is not less than the set increase width ΔT1.
As described above, the control device 20 determines the operating state of the vehicle equipped with the engine 11 based on the coolant temperature T, the fuel injection amount Q, the accelerator opening degree Ac, the vehicle speed v, the engine speed Ne, and these five pieces of information. presume. Then, the control device 20 determines the drive ratio R based on the control map associated with the estimated operating state and the coolant temperature T. The control device 20 calculates the target rotational speed TFS of the fan 14 based on the determined drive ratio R and the engine rotational speed Ne. Then, the control device 20 controls the fan rotation speed FS by feedback control based on the calculated target rotation speed TFS and the current rotation speed of the fan 14. Thereby, the fan 14 is driven at a rotational speed corresponding to the driving state of the vehicle and the coolant temperature T.

As described above, according to the control device 20 of the present embodiment, the effects listed below can be obtained.
(1) The fan rotation speed FS of the fan 14 is set from the control map for each driving state of the vehicle and the coolant temperature T. As a result, the fan 14 can be rotated at a rotational speed commensurate with the increase in the temperature of the engine coolant. Therefore, as compared with the case where the fan is driven at a rotational speed higher than the rotational speed required for cooling the engine 11, the loss of the engine output due to the driving of the fan 14 is suppressed, and the temperature of the engine 11 is set to a predetermined value. It becomes possible to improve the fuel consumption while keeping within the range.

  (2) In addition, the coolant temperature T is easily maintained at a high temperature and the engine oil is at a high temperature as compared with the case where the fan 14 is driven at a rotational speed higher than the rotational speed required for cooling the engine 11. Since it is easily maintained, loss of engine output due to engine friction can also be suppressed.

  (3) Further, in the start / acceleration state where the vehicle is starting and accelerating, the coolant temperature T is often sufficiently lower than in other driving states. On the other hand, since such a start / acceleration state is normally in a low speed and high load state, if the driving state is simply estimated according to the load state, even for such a start / acceleration state, The same control map as in the high load state is used. In this regard, in the above-described embodiment, different control maps are used for the start / acceleration state and the high load state. Therefore, the above-described effect becomes more remarkable.

  (4) Since the control map corresponding to each operation state is stored in advance, even if the coolant temperature T is the same, the fan rotation speed FS corresponding to the normal state, the high load state, the start / acceleration state Thus, the fan 14 can be rotated.

  (5) Comparing the normal map 24a and the high load map 24b, the fan 14 is driven at a lower temperature in the high load map 24b, and the driving is equal to or higher than the drive ratio R in the normal map 24a even at the same temperature. A ratio R is set. According to such a configuration, it is possible to realize the cooling of the engine 11 in a high load state and the improvement of fuel consumption in a normal state with higher probability.

  (6) In the driving state where the vehicle starts and accelerates, the coolant temperature T is often sufficiently lower than other driving states, and the driving state in which the engine output is particularly required. But there is. In this regard, as described above, since the fan 14 is stopped in the start / acceleration state, it is possible to improve the fuel efficiency and to suppress a decrease in the acceleration performance of the vehicle.

  (7) Moreover, if the coolant temperature T is higher than the third set temperature T3 (step S13: NO), the start / acceleration state is not selected even if the vehicle is accelerating. Therefore, it is possible to prevent the acceleration performance of the vehicle from deteriorating while suppressing the engine coolant from excessively rising due to the stop of the fan 14 at the start / acceleration.

  (8) When the state where the injection amount Q1 is equal to or greater than the set injection amount Q1 continues for a certain period FP, or when the increase width ΔT of the coolant temperature T in the certain period FP is equal to or greater than the set increase width ΔT1, It is estimated to be. By setting such conditions, it is possible to suppress frequent switching of the control map.

In addition, the said embodiment can also be suitably changed and implemented as follows.
The parameter used for the above-described operation state estimation process may be at least one parameter of engine coolant temperature, fuel injection amount, vehicle speed, accelerator opening, and engine speed, and other parameters. May be used.

-In the said driving | running state estimation process, you may omit step S13. Even with such a configuration, it is possible to obtain the effects according to the above (1) to (6).
In the above embodiment, the start / acceleration map may be associated with a drive ratio R equal to or less than the drive ratio R associated with the same coolant temperature T in the high load map and the normal map. That is, when the driving state is estimated to be the start / acceleration state in the driving state estimation process, the rotation of the fan 14 may be suppressed more than the high load state and the normal state. Even in such a configuration, since the rotation of the fan is suppressed as compared with the case where the operation state is a high load state or a normal state, in addition to the effects according to the above (1) to (5), the above (6) It is possible to obtain an effect according to the above.

  In the normal map 24a and the high load map 24b, the drive ratio R may be set so that the fan 14 is driven from the same coolant temperature T. Further, the start temperature at which the fan 14 is driven in the normal map 24a is higher than the start temperature at which the fan 14 is driven in the high load map 24b, and the drive ratio R in the normal map 24a is the high load map 24b. The drive ratio R may be lower. The point is that the fuel consumption can be improved by using the normal map 24a in the normal state. Even with such a configuration, it is possible to obtain the effects according to the above (1) to (4).

  A plurality of control maps may be associated with each operating state. For example, when the control map in the high load state is composed of a first high load map and a second high load map, a threshold is set for the engine speed Ne, and the first high load map and second The high load map may be switched. According to such a configuration, since the engine coolant can be controlled with higher accuracy, further improvement in fuel consumption is expected.

In addition, when a plurality of control maps are associated with each operation state, the drive amount specified in the control map is not limited to the drive ratio R but may be the target rotation speed TFS itself.
The fan 14 is not limited to the one driven by the rotational force of the output shaft 11a of the engine 11 transmitted by the fan clutch 13, but is driven by the electric power generated by the rotation of the output shaft 11a of the engine. An electric fan may be used.

  Ac ... accelerator opening, FP ... fixed period, FS ... fan rotation speed, Ne ... engine rotation speed, Q ... fuel injection amount, R ... drive ratio, TFS ... target rotation speed, T ... coolant temperature, [Delta] T ... increase range , V ... vehicle speed, 11 ... engine, 11a ... output shaft, 12 ... radiator, 13 ... fan clutch, 14 ... fan, 20 ... control device, 21 ... input unit, 22 ... main control unit, 23 ... storage unit, 24a ... Map, 24b ... High load map, 24c ... Start / Acceleration map, 25 ... PWM controller, 31 ... Temperature detection sensor, 32 ... Fuel injection amount sensor, 33 ... Accelerator opening sensor, 34 ... Vehicle speed sensor, 35 ... Engine rotation Speed sensor 36 ... Fan rotation speed detection sensor.

Claims (5)

A fan control device for controlling rotation of a fan for cooling a vehicle engine,
A driving state estimating unit for estimating a driving state of the vehicle;
A storage unit that stores, for each operating state, a control map in which the temperature of the engine coolant and the driving amount of the fan are associated;
A rotation speed calculation unit that calculates the rotation speed of the fan from the control map corresponding to the operation state estimated by the operation state estimation unit and the temperature of the engine coolant;
The operating state estimation unit
A start / acceleration state, which is a driving state in which the vehicle starts and accelerates,
A high load state in which the temperature rise in the engine coolant is a relatively large operating state;
One of the normal states that is an operation state in which the temperature rise in the engine coolant is relatively small is estimated. In the storage unit,
A high load map which is the control map corresponding to the high load state;
A normal map that is the control map corresponding to the normal state;
A start / acceleration map that is the control map corresponding to the start / acceleration state is stored,
In the high load map,
The drive amount of the fan is associated with the temperature of the engine coolant in a range equal to or higher than the first set temperature,
The normal map includes
The fan control device according to claim 1, wherein the drive amount of the fan is associated with a range in which the temperature of the engine coolant is equal to or higher than a second set temperature that is higher than the first set temperature. In the start / acceleration map,
The driving amount less than or equal to the driving amount associated with the same temperature in the high load map and the normal map is set over the entire range of the temperature of the engine coolant. The described fan control device. The operating state estimation unit
The fan control device according to claim 3, wherein the start / acceleration state is estimated on condition that the temperature of the engine coolant is lower than a predetermined temperature. The operating state estimation unit
The fan control device according to any one of claims 1 to 4, wherein the operating state is estimated based on a temperature of an engine coolant, a fuel injection amount, a speed of the vehicle, an accelerator opening, and an engine rotation speed.

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