CONTROLDEVICE FOR VEHICLE, CONTROL METHOD FOR VEHICLE, AND METHOD FOR ESTIMATING POWER CONSUMPTION OF COOLING FAN

FIELD OF THE INVENTION

[0001] The present invention relates to a control device for a vehicle which comprises an internal combustion engine, and a cooling device including a cooling fan used for cooling of a device the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan; and to a control method for such a vehicle, and to a method for estimating power consumption of a cooling fan.

BACKGROUND OF THE INVENTION

[0002] To connect a cooling fan which blows air at a radiator used for cooling an internal combustion engine which is mounted to a vehicle to the internal combustion engine via a fluid coupling is disclosed in Japanese Laid-Open Patent Publication Heisei 10-89386. In the structure of such a fluid coupling, a space within a housing is demarcated by a partition plate into a reservoir chamber and a drive chamber which acts as a torque transmission unit. By deformation of a bimetal which is located more to the rear of the vehicle than its radiator according to the temperature of the air after it has passed through the radiator, supply orifices in the partition plate are opened and closed, so that the amount of oil which is supplied from the reservoir chamber into the drive chamber is adjusted. By adjusting the amount of oil supplied from the reservoir chamber into the drive chamber, the torque transmitted by the fluid coupling is varied, so that the rotational speed of the cooling fan is adjusted.

[0003] By the way if, when controlling the operation of an internal combustion

engine, it is arranged to estimate the power consumption of an auxiliary unit which consumes power from the internal combustion engine, and to reflect this in the operational control of the internal combustion engine, then it is possible to perform the operational control of the internal combustion engine in a more appropriate manner. Furthermore, it is possible to enhance the running feeling of the vehicle. In this case, it is also possible to consider using a predetermined value as the power consumption of the auxiliary unit, according to whether or not it is in operation. However, with a vehicle which is equipped with a cooling device which cools the internal combustion engine by transmitting power from the internal combustion engine to the cooling fan via a fluid coupling as described above, the power consumed by the cooling fan varies greatly according to the state of the fluid coupling (i.e. according to the amount of oil which is supplied to its drive chamber). Due to this, if such a predetermined value is used, the accuracy of estimation is decreased. As a result, sometimes it happens that it becomes impossible to control the operation of the internal combustion engine in an appropriate manner, which is undesirable.

DISCLOSURE OF THE INVENTION

[0004] The control device for a vehicle and the method for estimating the power consumption of a cooling fan according to the present invention take it as one of their objects to estimate the power consumption of a cooling fan of a cooling device, the cooling fan being one auxiliary unit which consumes power from the internal combustion engine, in a more accurate manner. Furthermore, the control device for a vehicle according to the present invention takes it as one of its objects to estimate the power consumption of an auxiliary unit which consumes power from the internal combustion engine more accurately, thus performing control of the operation of the internal combustion engine in a more appropriate manner. Moreover, the control device for a vehicle according to the present invention takes it as one of its objects to estimate the power consumption of an auxiliary unit which consumes power from the internal

combustion engine more accurately, thus performing control of the starting of the internal combustion engine in a more appropriate manner.

[0005] The control device for a vehicle and the method for estimating the power consumption of a cooling fan according to the present invention employ the means detailed below for attaining at least a portion of the objective described above.

[0006] A first aspect of the present invention relates, in a vehicle including an internal combustion engine and a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, to a control device for a vehicle. And this control device for a vehicle includes a fan side rotational speed detection means which detects the rotational speed of the fluid coupling on the side of the cooling fan, and a power consumption estimation means which estimates the power consumption of the cooling fan, based at least upon the rotational speed on the side of the cooling fan which has been detected.

[0007] With this first aspect of the present invention, in a vehicle including an internal combustion engine and a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, the power consumption of the cooling fan is estimated based at least upon the rotational speed on the side of the cooling fan. This is based upon the fact that the rotational speed of the cooling fan is adjusted according to the state of the fluid coupling, and upon the fact that the state of the fluid coupling exerts a great influence upon the power consumption of the cooling fan. Due to this, it is possible to make a more accurate estimate of the power consumption of the cooling fan. Here, in the term "device", there is included a heat exchanger which is used for cooling the internal combustion engine, or

a heat exchanger of an air conditioning device, or, in the case of a vehicle which incorporates an electric motor for propulsion, a heat exchanger or the like which is used for cooling an electrical drive system related to this electric motor.

[0008] With this first aspect of the present invention, there may be included an engine side rotational speed detection means which detects the rotational speed of the fluid coupling on the side of the internal combustion engine. Furthermore, it would also be acceptable to arrange for the power consumption estimation means to be a means which estimates the power consumption of the cooling fan, based upon the rotational speed on the side of the cooling fan which has been detected, and upon the rotational speed on the side of the internal combustion engine which has been detected. If this is done, it is possible to estimate the power consumption of the cooling fan yet more accurately.

[0009] A second aspect of the present invention relates, in a vehicle including an internal combustion engine and a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, to a control device for a vehicle. And this control device for a vehicle includes an engine side rotational speed detection means which detects the rotational speed of the fluid coupling on the side of the internal combustion engine, a state estimation means which estimates the state of the fluid coupling, and a power consumption estimation means which estimates the power consumption of the cooling fan, based upon the rotational speed on the side of the internal combustion engine which has been detected, and upon the state of the fluid coupling which has been estimated.

[0010] With this second aspect of the present invention, in a vehicle including an internal combustion engine and a cooling device including a cooling fan used for cooling of a device the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along

with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, the power consumption of the cooling fan is estimated, based upon the rotational speed on the side of the internal combustion engine, and upon the state of the fluid coupling. Due to this, it is based upon the fact that the state of the fluid coupling exerts a great influence upon the power consumption of the cooling fan. Because of this, it is possible to estimate the power consumption of the cooling fan more accurately.

[0011] With this second aspect of the present invention, the state estimation means may include an engine side rotational speed detection means which detects the rotational speed of the fluid coupling on the side of the internal combustion engine, and a fan side rotational speed detection means which detects the rotational speed of the fluid coupling on the side of the cooling fan. And it would also be acceptable to arrange for the means to estimate the state of the fluid coupling, based upon the rotational speed on the side of the internal combustion engine which has been detected, and upon the rotational speed on the side of the cooling fan which has been detected. And it would also be acceptable for the fluid coupling to be made so as to adjust the amount of the viscous fluid which is supplied to the power transmission unit, according to the temperature of the device, and to arrange for the state estimation means to include a temperature detection means which detects the temperature of the device, and to be a means which estimates the state of the fluid coupling based upon the temperature of the device which has been detected. This is done, it is possible to estimate the state of the fluid coupling in a more accurate manner. Here, in the state of the fluid coupling, is included the adjustment state of the amount of the viscous fluid which is supplied to the power transmission unit. [0012] Moreover, with either the first or the second aspect of the present invention, it would be acceptable for the power consumption estimation means to be a means which estimates the power consumption of an auxiliary unit which is driven from and consumes power from the internal combustion engine, and to include an operation control means which controls the operation of the internal combustion engine based upon

the power consumption of the auxiliary unit which has been estimated. By doing this, it is possible to perform operation control of the internal combustion engine in a more accurate manner. With either the first or the second aspect of the present invention, it would also be acceptable to arrange for the operation control means to be a means which controls the operation of the internal combustion engine, so that the power which is lacking based upon the estimation of the power consumption of the auxiliary unit is outputted from the internal combustion engine.

[0013] Furthermore, with this second aspect of the present invention, it would also be acceptable to arrange for the state estimation means to estimate the amount of the viscous fluid which is supplied to the power transmission unit.

[0014] Moreover, with either the first or the second aspect of the present invention, it would also be acceptable to provide an output setting means which sets a target output for the internal combustion engine based upon input to the vehicle. In this case, it would also be acceptable for the operation control means to be a means which controls the operation of the internal combustion engine, so that the power, obtained by integrating the target output of the internal combustion engine which has been set by the output setting means and the power consumption of the auxiliary unit which has been estimated, is outputted by the internal combustion engine.

[0015] With the second aspect of the present invention, it would also be acceptable to arrange for the engine side rotational speed detection means to detect the time rate of change of the rotational speed of the fluid coupling on the side of the internal combustion engine. Moreover, it would also be acceptable to arrange for the fan side rotational speed detection means to detect the time rate of change of the rotational speed of the fluid coupling on the side of the cooling fan. It would also be acceptable to arrange for the power consumption estimation means to estimate the power consumption of the cooling fan, based upon the time rate of change of the rotational speed of the fluid coupling on the side of the internal combustion engine which has been detected, and the time rate of change of the rotational speed of the fluid coupling on the side of the cooling fan which has been detected.

[0016] With the second aspect of the present invention, it would also be acceptable to include a vehicle speed detection means which detects the speed of the vehicle. In this case, it would also be acceptable to arrange for the power consumption estimation means to estimate the power consumption of the cooling fan, based upon the vehicle speed which has been detected, upon the time rate of change of the rotational speed on the side of the internal combustion engine which has been detected, and upon the time rate of change of the rotational speed on the side of the cooling fan which has been detected.

[0017] A third aspect of the present invention is a control device for a vehicle including an internal combustion engine, a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, and a motoring means which is capable of motoring the internal combustion engine, which stops the operation of the internal combustion engine automatically when a predetermined stoppage condition has become effective, and starts the operation of the internal combustion engine automatically when, with the operation of the internal combustion engine stopped, the predetermined starting condition has become effective; and takes, as its gist, a state estimation means which estimates the state of the fluid coupling, and a starting control means which, when the predetermined starting condition has become effective, sets a target torque based upon the state of the fluid coupling which has been estimated, and controls the motoring means and the internal combustion engine, so that the internal combustion engine is motored with the target torque which has been set, and is started.

[0018] With this third aspect of the present invention, it relates to a control device for a vehicle, in a vehicle which includes an internal combustion engine, a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion

engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, and a motoring means which is capable of motoring the internal combustion engine. This control device for a vehicle estimates the state of the fluid coupling, and sets a target torque based upon the state of the fluid coupling which has been estimated and controls the motoring means and the internal combustion engine, so that the internal combustion engine is motored with the target torque which has been set, and is started. Since the state of the fluid coupling is estimated and is reflected in the target torque when motoring the internal combustion engine, accordingly it is possible to perform motoring of the internal combustion engine in an appropriate manner, and to start it, irrespective of the state of the fluid coupling, and thus it is possible to perform starting of the internal combustion engine in an appropriate manner. Here, the state of the fluid coupling includes the adjustment state of the viscous fluid which is supplied to its power transmission unit. [0019] Furthermore, with this third aspect of the present invention, it would alto be acceptable to arrange to stop the operation of the internal combustion engine automatically when a predetermined stoppage condition has become effective, and to start the operation of the internal combustion engine automatically when, with the operation of the internal combustion engine stopped, the predetermined starting condition has become effective.

[0020] And, with this third aspect of the present invention, it would also be acceptable to include a storage means for storing data, and for the state estimation means to include an engine side rotational speed detection means which detects the rotational speed of the fluid coupling on the side of the internal combustion engine, and a fan side rotational speed detection means which detects the rotational speed of the fluid coupling on the side of the cooling fan, and to be a means which, along with estimating the state of the fluid coupling based upon the rotational speed on the side of the internal combustion engine, and upon the rotational speed on the side of the cooling fan, which have been detected during operation of the internal combustion engine, also stores the estimated

state of the fluid coupling in the storage means. Moreover, it would also be acceptable to arrange for the fluid coupling to be so adapted that the amount of the viscous fluid which is'supplied to the power transmission unit is adjusted according to the temperature of the device, and for the state estimation means to include a temperature detection means which detects the temperature of the device, and to be a means which estimates the state of the fluid coupling based upon the temperature which has been detected. If this is done, it is possible to estimate the state of the fluid coupling in a more accurate manner.

[0021] A fourth aspect of the present invention relates, for a vehicle including an internal combustion engine and a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, to a power consumption estimation method for estimating the power consumption of the cooling fan. And the power consumption of the cooling fan is estimated, based upon the rotational- speed on the side of the cooling fan, and upon the rotational speed on the side of the internal combustion engine.

[0022] With this fourth aspect of the present invention, in a vehicle including an internal combustion engine and a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, the power consumption of the cooling fan is estimated, based at least upon the rotational speed of the fluid coupling on the side of the cooling fan. This is based upon the fact that the rotational speed on the side of the cooling fan is adjusted according to the state of the fluid coupling, and upon the fact that the state of the fluid coupling exerts a great influence upon the power consumption of the cooling fan. Due to this, it is possible to estimate the power consumption of the cooling fan in a more accurate manner. Here, in

the term "device", there is included a heat exchanger which is used for cooling the internal combustion engine, or a heat exchanger of an air conditioning device, or, in the case of a vehicle which incorporates an electric motor for propulsion, a heat exchanger or the like which is used for cooling an electrical drive system related to this electric motor. [0023] A fifth aspect of the present invention relates to, for a vehicle including an internal combustion engine and a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, a power consumption estimation method for estimating the power consumption of the cooling fan. And this power consumption estimation method includes a step of detecting the rotational speed of the fluid coupling on the side of the cooling fan, and a step of estimating the power consumption of the cooling fan, based upon the rotational speed on the side of the cooling fan which has been detected.

[0024] A sixth aspect of the present invention relates to, for a vehicle including an internal combustion engine and a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, a power consumption estimation method for estimating the power consumption of the cooling fan. And this power consumption estimation method includes a step of detecting the rotational speed of the fluid coupling on the side of the internal combustion engine, a step of estimating the state of the fluid coupling; and a step of estimating the power consumption of the cooling fan, based upon the rotational speed on the side of the internal combustion engine which has been detected, and upon the state of the fluid coupling which has been detected.

[0025] A seventh aspect of the present invention relates to, for a vehicle

including an internal combustion engine, a cooling device including a cooling fan used for cooling of a device, the cooling fan being one auxiliary unit which is driven along with consuming power from the internal combustion engine, and a fluid coupling which, along with adjusting the amount of a viscous fluid which is supplied to a power transmission unit, also transmits power from the internal combustion engine to the cooling fan, and a motoring means which is capable of motoring the internal combustion engine, a control method for a vehicle. And this control method for a vehicle includes a step of estimating the state of the fluid coupling, a step of, when a predetermined starting condition becomes effective, setting a target torque based upon the state of the fluid coupling which has been estimated; and a step of controlling the motoring means and the internal combustion engine, so that the internal combustion engine is motored with the target torque which has been set, and is started.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The foregoing and further objects, features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein: Fig. 1 is a structural diagram showing the schematic structure of a vehicle as one embodiment of the present invention;

Fig. 2 is a structural diagram showing the schematic structure of a fluid coupling;

Fig. 3 is a flow chart showing an example of a drive control routine which is executed by an electronic control unit of this embodiment;

Fig. 4 is a flow chart showing an example of auxiliary machinery energy consumption estimation processing, which is executed by the electronic control unit of this embodiment;

Fig. 5 is an explanatory figure showing an example of a map for setting fan

energy consumption;

Fig. 6 is a flow chart showing an example of a starting control routine which is executed by the electronic control unit of this embodiment;

Fig. 7 is a flow chart showing an example of a coupling state estimation routine which is executed by the electronic control unit of this embodiment;

Fig. 8 is an explanatory figure showing an example of a map for setting coupling state; and

Fig. 9 is an explanatory figure showing an example of a relationship between pulley rotational speed Np, coupling state F, and fan energy consumption Pf.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Next, the present invention will be explained, using a preferred embodiment of implementation thereof. [0028] Fig. 1 is a structural diagram showing the schematic structure of a vehicle 20, as an embodiment of the present invention. As shown in the figure, this vehicle 20 of the embodiment comprises an engine 22, an automatic transmission 26, a starter motor 28 (shown in the figure as ST), an alternator 36, a battery 38, an auxiliary machine 39, a cooling device 40, and an electronic control unit 70. The engine 22 is an internal combustion engine which outputs power from a hydrocarbon type fuel such as gasoline or light oil or the like. The automatic transmission 26 changes the speed of power which is outputted from a crank shaft 24 of the engine 22 and transmits it to vehicle wheels 34a and 34b via a differential gear 32. The starter motor 28 is made to be capable of motoring the engine 22. The alternator 36 generates electricity using power from the engine 22. The battery 38 can give electrical power to the starter motor 28 and accept electrical power from the alternator 36. The auxiliary unit 39 is driven by electrical power generated by the alternator 36, or by electrical power from the battery 38. The cooling device 40 cools the engine 22 by power from the engine 22, using cooling water. The electronic control unit 70 performs overall control of the vehicle. It should

be understood that, to this vehicle 20 of this embodiment, as auxiliary units which are driven while consuming power from the engine 22, apart from the alternator 36 and the cooling device 40 described above, there are also mounted a power steering device and the compressor of an air conditioner and the like, not shown in the figures. [0029] The cooling device 40 comprises a radiator 42, a water pump 44, and a cooling fan 46. The radiator 42 performs heat exchange between the cooling water of the engine 22 and the external air. The water pump 44 is driven by the power of the engine 22, and circulates the cooling water around a circulation path 43 which connects together the radiator 42 and the engine 22. And the cooling fan 46 is rotationally driven by power inputted from the engine 22, via a fluid coupling 50.

[0030] A pulley 50a is fixed to an input shaft 51 of the fluid coupling 50, and a belt 23 is extended between this pulley 50a and a pulley 22a of the engine 22. By this structure, the fluid coupling 50 is built so as to be able to transmit the power which is inputted from the engine 22 to the cooling fan 46 using a drive fluid (drive oil) such as silicon oil or the like. Fig. 2 is a structural diagram showing the schematic structure of this fluid coupling 50. As shown in this figure, the fluid coupling 50 comprises a housing 54, a disk 56, a partition plate 58, and an actuator unit 60. The cooling fan 46 is fitted upon the outer circumferential edge of the housing 54, which is supported upon the input shaft 51 via a bearing 52 so as to be free to rotate thereupon. And, along with being contained within the housing 54, the disk 56 is fixed upon the end of the input shaft 51, so as to transmit power which has been inputted to the input shaft 51 to the housing 54 using drive oil. The partition plate 58, along with partitioning the space within the housing 54 into a reservoir chamber 61 which stores drive oil and a drive chamber 62 which contains the disk 56, is also formed with supply orifices 58a which can be opened so as to supply drive oil from the reservoir chamber 61 to the drive chamber 62, or can be closed. The actuator unit 60 opens and closes these supply orifices 58a in the partition plate 58.

[0031] The housing 54 comprises a main body portion 54b and a cover portion 54a, and these are connected together by bolts 55. Although this feature is not shown in

the figure, in this housing 54 there are formed passages to circulate the drive oil charged in the drive chamber 62 back to the reservoir chamber 61 by using the rotation of the disk 56.

[0032] Along with concavo-convex ribs 56a being formed upon the outer peripheral portion of the disk 56, similar ribs 63 are also formed upon the inner wall of the cover portion 54a of the housing 54. When the cover portion 54a has been fitted to the main body portion 54b, the ribs 56a of the disk 56 and the ribs 63 of the cover portion 54a mesh into one another with predetermined gaps left between them, whereby a labyrinth groove is formed, which serves as a torque transmission section. Due to this, when the disk 56 is rotated in the state with drive oil being charged into this labyrinth groove, the rotatory torque can be transmitted due to the viscous resistance of the drive oil, and the housing 54 (and the cooling fan 46) can be rotationally driven.

[0033] The actuator unit 60 comprises a bimetal 60a, which is disposed at the front thereof with respect to the direction of forward movement of the vehicle, and at the rear of the radiator 42. The supply orifices 58a in the partition plate 58 are opened and closed along with deformation of this bimetal 60, and thereby it becomes possible to adjust the amount of drive oil which is supplied from the reservoir chamber 61 to the drive chamber 62. In other words, when the temperature of the ambient atmosphere in the vicinity of the bimetal 60a (i.e. the temperature of the wind which has passed through the radiator 42) is low, the supply orifices 58a of the partition plate 58 are closed due to the deformation of the bimetal 60a, and the amount of drive oil which is supplied from the reservoir chamber 61 into the drive chamber 62 becomes smaller. Accordingly, the torque which is transmitted from the disk 56 to the housing 54 becomes smaller. As a result, the rotational speed of the cooling fan 46 becomes lower. On the other hand, when the temperature of the ambient atmosphere in the vicinity of the bimetal 60a becomes high, the supply orifices 58a of the partition plate 58 are opened due to the deformation of the bimetal 60a, and the amount of drive oil which is supplied from the reservoir chamber 61 into the drive chamber 62 becomes larger. Accordingly, the torque which is transmitted from the disk 56 to the housing 54 becomes larger. As a result, the

rotational speed of the cooling fan 46 becomes higher. In this manner, the actuator unit 60 adjusts the rotational speed of the cooling fan 46.

[0034] The belt 23 is also extended between the pulley 22a of the engine 22 and a pulley 36a which is mounted upon the rotation shaft of the alternator 36. Thus, it becomes possible for the alternator 36 to be driven by the power from the engine 22 and to generate electricity. This electrical power which has been generated by the alternator

36 is used for charging up the battery 38, and for driving the auxiliary unit 39.

[0035] The electronic control unit 70 comprises a micro processor, a main portion of which is a CPU 72. And, apart from the CPU 72, the electronic unit 70 comprises a ROM 74 which stores a processing program, a RAM 76 which temporarily stores data, and input ports and output ports not shown in the figure. To this electronic control unit 70, via input ports thereof, there are inputted the engine rotational speed Ne, the fan rotational speed Nf, the shift position SP, the accelerator opening amount Ace, the brake pedal position BP, the vehicle speed V, and the like. The engine rotational speed Ne is detected by a rotational speed sensor 25 which is fitted to the crank shaft 24 of the engine 22. The fan rotational speed Nf is detected by a rotational speed sensor 47 which is fitted to the cooling fan 46. The shift position SP is detected by a shift position sensor 82 which detects the actuation position of a shift lever 81. The accelerator opening amount Ace is detected by an accelerator pedal position sensor 84 which detects the amount by which an accelerator pedal 83 is stepped upon. The brake pedal position BP is detected by a brake pedal position sensor 86 which detects the amount by which a brake pedal 85 is stepped upon. The vehicle speed V is detected by a vehicle speed sensor 88. And from the electronic control unit 70, via output ports thereof, there are outputted a control signal to the engine 22, a control signal for the automatic transmission 26, a drive signal to the starter motor 28, a drive signal to the alternator 36, and the like.

[0036] The basic control (idling stop control) for the vehicle 20 of this embodiment having the above structure will now be explained. When a predetermined stoppage condition is satisfied, such as, with the vehicle being stopped, along with the accelerator pedal 83 not being stepped upon and the accelerator being OFF, also the brake

pedal 85 is being stepped down upon and the brake is in the ON state, and the engine rotational speed Ne is less than or equal to a predetermined rotational speed or the like, then the engine 22 is automatically stopped. When a predetermined starting condition is satisfied, such as the accelerator becoming ON along with the brake being taken OFF, or the like, then the engine 22 is automatically started by the starter motor 28 using the electrical power from the battery 38.

[0037] The operation of the vehicle 20 of this embodiment having the above structure will now be explained. Fig. 3 is a flow chart showing an example of a drive control routine which is executed by the electronic control unit 70 of this embodiment. This routine is executed repeatedly at a predetermined time cycle.

[0038] When this drive control routine is executed, first, data such as the accelerator opening amount Ace from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the engine rotational speed Ne from the rotational speed sensor 25, and the like are inputted by the CPU 72 of the electronic control unit 70 (in a step SlOO). A target throttle opening amount TH* for the engine 22 is set based upon this accelerator opening amount Ace which has been inputted in the step SlOO. Along with this, a target speed ratio γ is set (in a step SIlO) for the automatic transmission 26, based upon the accelerator opening amount Ace and the vehicle speed V.

[0039] Next, the auxiliary unit energy consumption Pa of the auxiliary units which are being driven while consuming power from the engine 22, such as the cooling fan 46 and the alternator 36 and the like, is estimated (in a step S 120). This auxiliary unit energy consumption estimation processing of the step S120 is shown in Fig. 4. As shown in Fig. 4, in this estimation of the auxiliary unit energy consumption Pa, the data which is necessary for the processing is inputted (in a step S 122), such as the engine rotational speed Ne and the fan rotational speed from the rotational speed sensor 47, the energy consumption Px of the auxiliary units which consume power from the engine 22 apart from the cooling fan 46, and the like. A pulley rotational speed Np, which is the rotational speed of the input shaft 51 of the fluid coupling 50 (i.e. of the pulley 50a), is calculated (in a step S 124) by multiplying the engine rotational speed Ne which has been

inputted in the step S 122 by a conversion coefficient (the pulley ratio). And the fan energy consumption Pf, which is the energy consumed by the cooling fan 46, is estimated (in a step S 126), based upon the pulley rotational speed Np which has been calculated in the step S 124 and upon the fan rotational speed Nf which has been inputted. And the auxiliary unit energy consumption Pa is set (in a step S 128) by adding the energy consumption Px which has been inputted to this fan energy consumption Pf which has been estimated in the step S126. Here, the energy consumption Px may be obtained by adding together the energy consumptions of the various auxiliary units. The derivation of the energy consumption of each of the auxiliary units may be performed in the following manner. For example, the electrical power which is being generated by the alternator 36 is detected. Or, for the energy consumption of an auxiliary unit such as the water pump 44, or a power steering device, a compressor of an air conditioner, or the like, a value according to its ON/OFF state and the engine rotational speed Ne may be used. With regard to the fan energy consumption Pf, in this embodiment, the relationship between the pulley rotational speed Np, the fan rotational speed Nf, and the fan energy consumption Pf is obtained in advance and is stored as a map for energy consumption estimation in the ROM 74. In the above, it has been supposed that, when the pulley rotational speed Np and the fan rotational speed Nf are given, the corresponding fan energy consumption Pf is set by derivation from the stored map. An example of such a map for setting the fan energy consumption is shown in Fig. 5. In Fig. 5, the fan energy consumption Pf is estimated based upon the pulley rotational speed Np (the engine rotational speed Ne) and the fan rotational speed Nf. The reason for this is based upon the fact that the fan rotational speed Nf corresponding to the pulley rotational speed Np is governed by the state of the fluid coupling 50 (i.e., by the amount of the drive oil which is being charged into the drive chamber 62 from the reservoir chamber 61), and by the fact that the state of the fluid coupling 50 exert a great influence upon the fan energy consumption Pf.

[0040] When the auxiliary unit energy consumption Pa has been estimated in this manner, the value obtained by dividing the auxiliary unit energy consumption Pa

which has been estimated by the rotational speed Ne of the engine which has been inputted is set as a compensation opening amount THset (in a step S 130). The target throttle opening amount TH* is compensated (in a step S 140) by adding the compensation opening amount THset which is set in the step S 130 to the target throttle opening amount TH*. And, along with drive controlling the engine 22 by this target throttle opening amount TH* which has been compensated in the step S 140, the automatic transmission 26 is drive controlled to a target speed change ratio γ (in a step S 150). And then this routine ends. By doing this, it is possible to perform appropriate drive control of the engine 22, irrespective of the magnitude of the auxiliary unit energy consumption Pa (i.e. of the fan energy consumption Pf). Furthermore, it is possible to enhance the driving feeling of the vehicle. For example, if this kind of control is employed when changing the speed change stage of the automatic transmission 26, then it is possible further to enhance the speed change feeling.

[0041] Next, the operation when a predetermined starting condition becomes effective and the engine 22 is started will be explained. Fig. 6 is a flow chart showing an example of a starting control routine which is executed by the electronic control unit 70 of this embodiment. This routine is executed when a predetermined starting condition becomes effective. When executing this starting control routine, first (in a step S200), the CPU 72 of the electronic control unit 70 inputs the coupling state F, which is the state of the fluid coupling 50 when the engine is operated the previous time. This coupling state F is set as the amount of drive oil which, according to estimation, is charged from the reservoir chamber 61 into the drive chamber 62. The coupling state F may be inputted by reading in a value which is stored in a predetermined region of the RAM 76, and which is estimated by a coupling state estimation routine of which an example is shown in Fig. 7. With the coupling state estimation routine of Fig. 7, first, the engine rotational speed Ne from the rotational speed sensor 25 and the fan rotational speed Nf from the rotational speed sensor 47 are inputted (in a step S202). Then (in a step S204) the pulley rotational speed Np is calculated as the rotational speed of the pulley 50a which is obtained by multiplying the engine rotational speed Ne which is

inputted in the step S202 by a conversion coefficient k. Then the coupling state F is estimated (in a step S206) based upon the pulley rotational speed Np which has been calculated in the step S204 and upon the fan rotational speed Nf. The coupling state F which has been estimated in the step S206 is stored in a predetermined region of the RAM 76 (in a step S208). In this embodiment, for the coupling state F, the relationship between the fan rotational speed Nf and the pulley rotational speed Np, and the coupling state F, is obtained in advance and is stored in the ROM 74 as a map for setting the coupling state. And, when the fan rotational speed Nf and the pulley rotational speed Np are provided, it is arranged to derive and to set the coupling state F which correspond thereto, based upon the map stored in the ROM 74. An example of this map for setting the coupling state is shown in Fig. 8. In the example of Fig. 8, the estimation of the coupling state F is broken down as three states: an ON state in which the supply orifices 58a of the partition plate 58 are approximately fully open, a MID state in which they are half open, and an OFF state in which they are approximately fully closed. And the coupling state F is estimated based upon the fan rotational speed Nf and the pulley rotational speed Np. The reason for this is based upon the fact that, as previously described, the fan rotational speed Nf is adjusted with respect to the pulley rotational speed Np according to the state of the fluid coupling 50 (i.e. according to the amount of drive oil which is charged from the reservoir chamber 61 into the drive chamber 62). [0042] When the coupling state F is inputted in this manner, a target motoring torque Tm* which must be outputted from the starter motor 24 is set (in a step S210) based upon this coupling state F which has been inputted. Here, in this embodiment, the target motoring torque Tm* has a tendency to become larger, the larger is the amount of drive oil which is charged into the drive chamber 62 (in this embodiment, in order, the OFF State, the MID state, and the ON state), which is the coupling state F; and the relationship between the coupling state F and the target motoring torque Tm* is obtained in advance and is stored in the ROM 74 as a map. • When the coupling state F is supplied, it is arranged to derive and to set the corresponding target motoring torque Tm* from the map which is stored in the ROM 74. This is based upon the fact that, the greater is the

amount of drive oil which is charged into the drive chamber 62, the greater does the resistance when motoring the engine 22 with the starter motor 24 become.

[0043] When the target motoring torque Tm* is set, the starter motor 24 is controlled (in a step S220) according to this target motoring torque Tm* which has thus been set. And fuel injection control and ignition control are performed for the engine 22

(in a step S230). After waiting for the engine 22 to fire up (in a step S240), this routine terminates.

[0044] According to the vehicle 20 of this embodiment as explained above, it is possible to estimate the fan energy consumption Pf of the cooling fan 46, based upon the engine rotational speed Ne on the engine 22 side of the fluid coupling 50 (i.e. the pulley rotational speed Np of the pulley 50a) and the fan rotational speed Nf on the cooling fan 46 side of the fluid coupling 50. Moreover, the engine 22 is drive controlled by compensating the target throttle opening amount TH* based upon the fan energy consumption Pf. Due to this, it is possible to perform driving control of the engine 22 in a more appropriate manner, and it is possible further to enhance the driving feeling.

[0045] Furthermore, according to the vehicle 20 of this embodiment, even while the engine 22 is being operated, the coupling state F of the fluid coupling 50 is estimated and stored in the RAM 76. When starting the stopped engine 22 upon the predetermined starting condition becoming effective, the engine 22 is motored with the starter motor whose target motoring torque Tm* is set based upon the estimated coupling state F which is stored in the RAM 76. Accordingly, it is possible to perform the starting of the engine 22 in a more appropriate manner.

[0046] With the vehicle 20 of this embodiment, it is arranged for the estimation of the fan energy consumption Pf to be performed based upon the engine rotational speed Ne (the pulley rotational speed Np) and the fan rotational speed Nf, using the map for setting the fan energy consumption shown in the example of Fig. 5. However, the present invention is not limited to this case; it would also be acceptable to arrange for the fan energy consumption Pf to be estimated by calculation according to an approximation equation, instead of from a map.

[0047] With the vehicle 20 of this embodiment, the fan energy consumption Pf is estimated based upon the engine rotational speed Ne (the pulley rotational speed Np) and the fan rotational speed Nf. However, if the change of the fan energy consumption Pf with respect to change of the engine rotational speed Ne is sufficiently small as to be ignored, as compared to the change of the fan energy consumption Pf with respect to change of the fan rotational speed Nf (refer to Fig. 5), then it is justifiable to estimate the fan energy consumption based only upon the fan rotational speed Nf.

[0048] With the vehicle 20 of this embodiment, the fan energy consumption Pf is estimated based upon the engine rotational speed Ne (the pulley rotational speed Np) and the fan rotational speed Nf. However, it would also be acceptable to arrange for, in addition, the fan energy consumption Pf to be estimated in consideration of the influence due to an inertia force based upon the time rate of change of the engine rotational speed Ne or the time rate of change of the fan rotational speed Nf. Moreover, it would also be acceptable to arrange for the fan energy consumption Pf to be estimated in consideration of the influence of an operating pressure which operates upon the cooling fan 46 due to the wind of motion based upon the vehicle speed V. In such cases, for example, it would be possible to set a compensation coefficient based upon the time rate of change of the engine rotational speed Ne or the time rate of change of the fan rotational speed Nf, or upon the vehicle speed V. And it would be acceptable to arrange to multiply this compensation coefficient which has been set into the fan energy consumption Pf which is based upon the engine rotational speed Ne (the pulley rotational speed Np) and the fan rotational speed Nf.

[0049] With the vehicle 20 of this embodiment, the fan energy consumption Pf is estimated based upon the engine rotational speed Ne (the pulley rotational speed Np) and the fan rotational speed Nf. However, it would also be acceptable to arrange for, along with the coupling state F being estimated, the fan energy consumption Pf to be estimated based upon the coupling state F which has thus been estimated and the engine rotational speed Ne (the pulley rotational speed Np). An example of a relationship between the coupling state F, the pulley rotational speed Np, and the fan energy

consumption Pf is shown in Fig. 9. It should be understood that the coupling state F may be estimated based upon the engine rotational speed Ne (the pulley rotational speed Np) and the fan rotational speed Nf, using the map shown by way of example in Fig. 8. Furthermore, the coupling state F (the amount of the drive oil which is charged into the drive chamber 62) may be adjusted according to the temperature of the ambient atmosphere in the vicinity of the radiator 42. Here, rather than the temperature of the radiator 42, a temperature sensor could be fitted to the rear of the vehicle, and the coupling state F could also be estimated based upon the temperature detected by this temperature sensor. Furthermore, it would also be possible to set and control a control target value based upon the temperature of the ambient atmosphere in the vicinity of a radiator 42 of a type which can control the actuator unit 60 of the fluid coupling 50 with a solenoid or the like. In this case, it would also be possible to estimate the coupling state F based upon this control target value.

[0050] With the vehicle 20 of this embodiment, it is arranged to estimate the coupling state F by dividing it into three cases: an ON state in which the supply orifices 58a of the partition plate 58 are approximately fully open, a MID state in which they are half open, and an OFF state in which they are approximately fully closed. However, it would also be acceptable to arrange to divide the coupling state F into two states, or into four or more states. [0051] With the vehicle 20 of this embodiment, it is arranged to employ the cooling fan 46 which is connected to the engine 22 via the fluid coupling 50 for blowing air through the radiator 42 which is used for cooling the engine 22. However, the present invention is not limited to this case. For example, it would also be acceptable to arrange to employ a cooling fan which is connected to the engine via a fluid coupling for blowing air through a condenser of an air conditioner.

[0052] With the vehicle 20 of this embodiment it is arranged to perform idling stop control, in which, when a predetermined stoppage condition becomes effective, the engine is automatically stopped, and when a predetermined starting condition becomes effective, the engine is automatically started. However, it would also be acceptable to

arrange not to perform this type of idling stop control.

[0053] With the vehicle 20 of this embodiment, it is arranged to transmit the power from the engine 22 to the driving wheels 34a and 34b while changing its speed with the automatic transmission 26. However, it would be possible to apply the present invention to the case of any vehicle which is equipped with a cooling fan 46 which is driven by input of power from an engine 22 via a fluid coupling 50. For example, it would also be acceptable to arrange to apply the present invention to a hybrid automobile which is equipped with both an internal combustion engine and also an electric motor as power sources for propulsion. In this case of applying the present invention to such a hybrid automobile, it would also be acceptable to arrange to apply it to a vehicle in which a cooling fan which is connected via a fluid coupling to an internal combustion engine blows air at a radiator which is used for cooling the electric motor, or an inverter which drives the electric motor.

[0054] Although a preferred implementation of the present invention has been explained above in terms of an embodiment thereof, the present invention is not to be considered as being limited in any way to this type of embodiment; the present invention can, of course, be implemented in various manners within its range, without departing from its scope.

[0055] The present invention can be applied in the vehicle manufacturing industry.