JP2008121609A - Vehicle and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve fuel economy in addition to securing necessary vehicle dynamic characteristics when instruction to give priority to fuel economy is issued. <P>SOLUTION: Fuel cut of an engine is suspended and fuel supply to the engine is resumed (S150, S170) if vehicle speed V becomes less than a threshold Vref2 smaller than a threshold Vref1 which is for a condition where an economical switch is turned on, under a condition where the economical switch is turned on when an accelerator is off. Consequently, duration of fuel cut of the engine 22 can be extended, and fuel economy can be improved more with keeping vehicle dynamic characteristics while vehicle dynamic characteristics are slightly dropped sometimes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle and a control method thereof, and more particularly, to a vehicle equipped with an internal combustion engine that outputs driving power and a control method thereof.

Conventionally, as this type of vehicle, there has been proposed a vehicle that changes the engine speed of fuel return according to the duration of clutch-off or neutral when stopping fuel to the engine during deceleration (for example, Patent Documents). 1). In this vehicle, the engine speed at the time of fuel return is set to 700 rpm when the clutch-off duration is less than 1 second, and is set to 900 rpm when the clutch-off duration exceeds 1 second, so that the clutch-off at the time of shift change is reduced. It improves fuel efficiency during short periods of time and prevents engine stalls when clutch-off and neutral durations are long.
Japanese Patent Laid-Open No. 5-231214

  By controlling the number of revolutions of fuel return to the engine that has stopped the fuel so that the above-mentioned vehicle can be cited as an example, it is possible to improve the fuel consumption and suppress the deterioration of the dynamic characteristics of the vehicle. However, there is a case where it is desired to improve the fuel consumption even with a slight decrease in the dynamic characteristics of the vehicle. From such a request, some vehicles are provided with a switch or the like for instructing priority on fuel efficiency, and it is desired to improve the fuel efficiency after ensuring the necessary dynamic characteristics of the vehicle.

  An object of the vehicle and its control method of the present invention is to improve the fuel consumption after securing the dynamic characteristics of the vehicle necessary when the fuel efficiency priority instruction is given.

  The vehicle and the control method thereof according to the present invention employ the following means in order to achieve the above-described object.

The first vehicle of the present invention is
A vehicle equipped with an internal combustion engine that outputs driving power,
A fuel efficiency priority instruction switch for instructing fuel efficiency priority;
Vehicle speed detection means for detecting the vehicle speed;
The internal combustion engine is configured such that when the accelerator is off, the fuel supply of the internal combustion engine is stopped when a predetermined fuel cut condition including a condition that the detected vehicle speed is equal to or higher than the vehicle speed based on the state of the fuel consumption priority instruction switch is satisfied. An accelerator off-time control means for controlling the engine and controlling the internal combustion engine to start the fuel supply when the predetermined fuel cut condition is not satisfied in a state where the fuel supply of the internal combustion engine is stopped;
It is a summary to provide.

  In the first vehicle of the present invention, when the accelerator is off, the fuel supply of the internal combustion engine is stopped when a predetermined fuel cut condition including a condition that the vehicle speed is equal to or higher than the vehicle speed based on the state of the fuel consumption priority instruction switch is satisfied. The internal combustion engine is controlled so that the fuel supply is started when a predetermined fuel cut condition is not satisfied. Thus, fuel cut can be executed according to the state of the fuel efficiency priority instruction switch, and fuel supply to the internal combustion engine can be started. That is, it is possible to improve the fuel efficiency while ensuring the necessary vehicle dynamic characteristics when the fuel efficiency priority instruction is given.

  In the first vehicle of the present invention, the accelerator-off time control means determines that the detected fuel speed is equal to or higher than the first vehicle speed when the fuel consumption priority instruction switch is off when the accelerator is off. The internal combustion engine is controlled so that the fuel supply to the internal combustion engine is stopped and started, and the detected vehicle speed is the first vehicle speed when the fuel efficiency priority instruction switch is on when the accelerator is off. It is a means for controlling the internal combustion engine so that the fuel supply of the internal combustion engine is stopped and started using one of the predetermined fuel cut conditions as a condition that the speed is smaller than the second vehicle speed. You can also. The first vehicle of the present invention further comprises continuously variable transmission means for continuously changing the power on the output shaft side of the internal combustion engine and outputting the power to the axle side, wherein the accelerator-off time control means is provided when the accelerator is off. It can also be means for controlling the continuously variable transmission means so that the internal combustion engine rotates at a predetermined rotational speed.

The second vehicle of the present invention is
A vehicle equipped with an internal combustion engine that outputs driving power,
A fuel efficiency priority instruction switch for instructing fuel efficiency priority;
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
When the accelerator is off, the fuel supply of the internal combustion engine is stopped when a predetermined fuel cut condition including a condition that the detected rotational speed is equal to or higher than the rotational speed based on the state of the fuel consumption priority instruction switch is satisfied. Accelerator-off time control means for controlling the internal combustion engine and controlling the internal combustion engine to start fuel supply when the predetermined fuel cut condition is not satisfied in a state where the fuel supply of the internal combustion engine is stopped. When,
It is a summary to provide.

  In the second vehicle of the present invention, when the accelerator is off, the internal combustion engine is operated when a predetermined fuel cut condition including a condition that the rotational speed of the internal combustion engine is equal to or higher than the rotational speed based on the state of the fuel efficiency priority instruction switch is satisfied. The internal combustion engine is controlled so that the fuel supply is stopped, and then the internal combustion engine is controlled to start the fuel supply when a predetermined fuel cut condition is not satisfied. Thus, fuel cut can be executed according to the state of the fuel consumption priority instruction switch and fuel supply to the internal combustion engine can be started. That is, it is possible to improve the fuel efficiency while ensuring the necessary vehicle dynamic characteristics when the fuel efficiency priority instruction is given.

  In such a second vehicle of the present invention, the accelerator-off time control means sets the predetermined fuel as a condition that the detected rotational speed is equal to or higher than the first rotational speed when the fuel consumption priority instruction switch is off when the accelerator is off. The internal combustion engine is controlled so that the fuel supply to the internal combustion engine is stopped and started as one of the cutting conditions. When the fuel consumption priority instruction switch is on when the accelerator is off, the detected rotational speed is Means for controlling the internal combustion engine so that the fuel supply to the internal combustion engine is stopped and started using one of the predetermined fuel cut conditions that is equal to or higher than a second rotational speed smaller than the first rotational speed; It can also be. The second vehicle of the present invention may further include stepped transmission means for shifting the power on the output shaft side of the internal combustion engine in a stepped manner and outputting it to the axle side.

The first vehicle control method of the present invention comprises:
A vehicle control method comprising: an internal combustion engine that outputs power for traveling; and a fuel efficiency priority instruction switch that instructs fuel efficiency priority,
The internal combustion engine is configured such that when the fuel efficiency priority instruction switch is off when the accelerator is off, the fuel supply of the internal combustion engine is stopped when a first fuel cut condition including a condition that the vehicle speed is equal to or higher than the first vehicle speed is satisfied. And controlling the internal combustion engine to start fuel supply when the first fuel cut condition is not established in a state where the fuel supply of the internal combustion engine is stopped, and the fuel consumption priority is given when the accelerator is off. The internal combustion engine is configured such that when the instruction switch is on, the fuel supply of the internal combustion engine is stopped when a second fuel cut condition including a condition that the vehicle speed is equal to or higher than a second vehicle speed that is smaller than the first vehicle speed is satisfied. The internal combustion engine so that the fuel supply is started when the second fuel cut condition is not established in a state where the fuel supply of the internal combustion engine is stopped. To control,
It is characterized by that.

  In the first vehicle control method of the present invention, when the fuel efficiency priority instruction switch is off when the accelerator is off, the internal combustion engine is satisfied when the first fuel cut condition including the condition that the vehicle speed is equal to or higher than the first vehicle speed is satisfied. The internal combustion engine is controlled so that the fuel supply is stopped, and then the internal combustion engine is controlled to start the fuel supply when the first fuel cut condition is not satisfied. On the other hand, when the fuel consumption priority instruction switch is on when the accelerator is off, the fuel supply to the internal combustion engine is stopped when the second fuel cut condition is satisfied, including the condition that the vehicle speed is equal to or higher than the second vehicle speed, which is smaller than the first vehicle speed. The internal combustion engine is controlled so that the fuel supply is started when the second fuel cut condition is not satisfied. Thus, fuel cut can be executed according to the state of the fuel efficiency priority instruction switch, and fuel supply to the internal combustion engine can be started. That is, it is possible to improve the fuel efficiency while ensuring the necessary vehicle dynamic characteristics when the fuel efficiency priority instruction is given.

The second vehicle control method of the present invention comprises:
A vehicle control method comprising: an internal combustion engine that outputs power for traveling; and a fuel efficiency priority instruction switch that instructs fuel efficiency priority,
When the fuel efficiency priority instruction switch is off when the accelerator is off, the fuel supply to the internal combustion engine is stopped when a first fuel cut condition including a condition that the rotational speed of the internal combustion engine is equal to or higher than the first rotational speed is satisfied. Controlling the internal combustion engine and controlling the internal combustion engine to start fuel supply when the first fuel cut condition is not satisfied in a state where the fuel supply of the internal combustion engine is stopped. When the fuel efficiency priority instruction switch is on when the accelerator is off, the internal combustion engine satisfies a second fuel cut condition including a condition that the rotational speed of the internal combustion engine is equal to or higher than a second rotational speed that is smaller than the first rotational speed. The internal combustion engine is controlled so that the fuel supply of the engine is stopped, and the second fuel cut condition is not satisfied in a state where the fuel supply of the internal combustion engine is stopped. Controlling the internal combustion engine to start fuel supply in,
It is characterized by that.

  In the second vehicle control method of the present invention, the first fuel cut condition including the condition that the rotational speed of the internal combustion engine is equal to or higher than the first rotational speed is satisfied when the fuel consumption priority instruction switch is off when the accelerator is off. The internal combustion engine is controlled so that the fuel supply to the internal combustion engine is stopped when the engine is running, and then the internal combustion engine is controlled to start the fuel supply when the first fuel cut condition is not satisfied. On the other hand, when the fuel efficiency priority instruction switch is on when the accelerator is off, the internal combustion engine has a second fuel cut condition that includes a condition that the rotational speed of the internal combustion engine is equal to or higher than the second rotational speed smaller than the first rotational speed. The internal combustion engine is controlled to stop the fuel supply, and then the internal combustion engine is controlled to start the fuel supply when the second fuel cut condition is not satisfied. Thus, fuel cut can be executed according to the state of the fuel efficiency priority instruction switch, and fuel supply to the internal combustion engine can be started. That is, it is possible to improve the fuel efficiency while ensuring the necessary vehicle dynamic characteristics when the fuel efficiency priority instruction is given.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of an automobile 20 as a first embodiment of the present invention. As shown in the figure, the automobile 20 of the first embodiment includes an engine 22 that is driven by injection control and ignition control of fuel such as gasoline and light oil by an engine electronic control unit (hereinafter referred to as engine ECU) 26, Steplessly controlled by an automatic transmission electronic control unit (hereinafter referred to as ATECU) 32 connected to a crankshaft 24 of the engine 22 and a drive shaft 34 coupled to drive wheels 38a and 38b via a differential gear 36. And an automatic continuously variable transmission 30 that can change the speed of the vehicle, and a vehicle electronic control unit 60 that controls the entire vehicle. The engine ECU 26 also calculates the rotational speed Ne of the engine 22 based on the crank position input from the crank position sensor 23 that detects the rotational position of the crankshaft 24 of the engine 22. The automatic continuously variable transmission 30 includes a torque converter with a lock-up mechanism and a continuously variable transmission. The continuously variable transmission includes, for example, a belt-type CVT (Continuously Variable Transmission). ing.

  The vehicular electronic control unit 60 is configured as a microprocessor centered on a CPU 62. In addition to the CPU 62, a ROM 64 that stores a processing program, a RAM 66 that temporarily stores data, and a timer 68 that measures time. And an input / output port and a communication port (not shown). The vehicle electronic control unit 60 includes an ignition signal from an ignition switch 70, a shift position SP from a shift position sensor 72 that detects the operation position of the shift lever 71, and an accelerator pedal position sensor 74 that detects the amount of depression of the accelerator pedal 73. The accelerator opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 76 for detecting the depression amount of the brake pedal 75, the vehicle speed V from the vehicle speed sensor 78, and the vehicle fuel efficiency of the vehicle attached to the vicinity of the driver's seat. The eco switch signal ESW from the eco switch 79 is input through the input port. The vehicle electronic control unit 60 is connected to the engine ECU 26 and the ATECU 32 via a communication port, and exchanges various control signals and data with the engine ECU 26 and the ATECU 32.

  Next, the operation of the automobile 20 of the first embodiment configured as described above will be described. FIG. 2 is a flowchart showing an example of an accelerator-off time control routine executed by the vehicle electronic control unit 60 of the first embodiment when the accelerator pedal 73 that has been depressed is turned off. This routine is repeatedly executed at predetermined time intervals (for example, every several milliseconds) while the accelerator is off. In the automobile 20 of the first embodiment, when the accelerator is off, the speed ratio of the automatic continuously variable transmission 30 is such that the rotational speed Ne of the engine 22 gradually decreases from about 1300 rpm and rotates at 1000 rpm, depending on the vehicle speed. The so-called coast control to be controlled is executed.

  When the accelerator off-time control routine is executed, the CPU 62 of the vehicle electronic control unit 60 first inputs data necessary for control such as the eco switch signal ESW from the eco switch 79 and the vehicle speed V from the vehicle speed sensor 78 ( Step S100), it is determined whether the input eco-switch signal ESW is on or off (Step S110). When the eco switch signal ESW is OFF, that is, when the driver is not instructing to give priority to fuel consumption, the vehicle speed V is compared with the threshold value Vref1 (step S120). When the vehicle speed V is equal to or higher than the threshold value Vref1, other fuels are compared. The fuel to the engine 22 is cut on the condition that the cutting condition is satisfied (step S130), and this routine is terminated. When the vehicle speed V is less than the threshold value Vref1, fuel is injected into the engine 22 ( Step S140), this routine is finished. Here, the threshold value Vref1 is set as a vehicle speed at which the fuel cut to the engine 22 is stopped and the fuel is supplied to the engine 22 when the eco switch 79 is turned off, for example, 20 km / h or 15 km. / H or the like can be used. Therefore, when the accelerator is turned off at a relatively high speed, the fuel cut of the engine 22 is performed. Thereafter, when the vehicle speed V reaches less than the threshold value Vref1, the fuel cut of the engine 22 is stopped and fuel injection to the engine 22 is performed. Resumed. Further, as the fuel cut condition, in addition to the above-described vehicle speed V being equal to or higher than the threshold value Vref1, the warm-up of the engine 22 has been completed, and the catalyst warm-up of the purification device attached to the exhaust pipe of the engine 22 Can be mentioned. The fuel cut is performed by transmitting a fuel cut control signal to the engine ECU 26 and executing it based on the control signal received by the engine ECU 26.

  On the other hand, when it is determined in step S110 that the eco switch signal ESW is on, it is determined that the driver gives an instruction to give priority to fuel consumption, and the vehicle speed V is compared with a threshold value Vref2 that is smaller than the threshold value Vref1 (step S150). When the vehicle speed V is equal to or higher than the threshold value Vref2, the fuel to the engine 22 is cut on condition that other fuel cut conditions are satisfied (step S160). When the vehicle speed V is determined to be less than the threshold value Vref2, the engine 22 Is injected (step S170), and this routine is terminated. Here, the threshold value Vref2 is set as a vehicle speed at which fuel cut to the engine 22 is stopped and fuel is supplied to the engine 22 when the eco switch 79 is on, and the eco switch 79 is off. For example, a smaller value such as 5 km / h or 10 km / h is used than the threshold value Vref1 at the time of being set. In this way, by reducing the vehicle speed at which the fuel cut to the engine 22 is stopped and the fuel supply is resumed when the eco switch 79 is on, compared to when the eco switch 79 is off. The fuel cut duration of the engine 22 can be extended, and the fuel consumption of the vehicle can be further improved.

  FIG. 3 is an explanatory diagram illustrating an example of a temporal change in the vehicle speed V and the fuel cut state of the engine 22 when the accelerator is off. As shown in the drawing, when the eco switch 79 is off, the fuel cut is turned off at time T2, but when the eco switch 79 is on, the fuel cut is turned off at time T3 later than time T2. That is, when the eco switch 79 is on, the fuel consumption is improved by delaying the time during which the fuel cut is turned off.

  According to the automobile 20 of the first embodiment described above, when the eco switch 79 is turned on when the accelerator is off, the vehicle speed at which the fuel cut of the engine 22 is stopped and the fuel supply to the engine 22 is resumed is set to the eco switch 79. Since the vehicle speed is smaller than when the engine is off, the fuel cut duration of the engine 22 can be lengthened, and the vehicle dynamic characteristics may be slightly reduced. The fuel consumption of the vehicle can be further improved after securing.

  In the automobile 20 of the first embodiment, the automatic continuously variable transmission 30 is configured by a torque converter with a lock-up mechanism and a belt type CVT, but a toroidal continuously variable transmission instead of the belt type CVT. It is good also as what comprises. In addition, a transmission other than the continuously variable transmission may be used as long as the rotation speed of the engine 22 is adjusted when the accelerator is off.

  Next, an automobile 20B according to a second embodiment of the present invention will be described. FIG. 4 is a configuration diagram showing an outline of the configuration of the automobile 20B of the second embodiment. As shown in FIGS. 4 and 1, the automobile 20B according to the second embodiment has an automatic continuously variable transmission 30B as the automatic continuously variable transmission 30B of the automobile 20 according to the first embodiment. The hardware configuration is the same as that of the automobile 20 of the first embodiment except that the ATECU 32 that controls the ATECU 32B is used to control the automatic stepped transmission 30B. Therefore, in order to abbreviate | omit duplicate description, about the structure same as the structure of the motor vehicle 20 of 1st Example among the structures of the motor vehicle 20B of 2nd Example, the same code | symbol is attached | subjected and the detailed description is Omitted. The automatic stepped transmission 30B mounted on the automobile 20B of the second embodiment is composed of a torque converter with a lock-up clutch and a stepped transmission, and examples of the stepped transmission include 4th speed and 5th speed. It is configured as a transmission.

  In the automobile 20B of the second embodiment configured as described above, when the accelerator pedal 73 that has been depressed is turned off, an accelerator-off time control routine illustrated in FIG. 5 is executed. This routine is repeatedly executed at predetermined time intervals (for example, every several milliseconds) while the accelerator is off. In the automobile 20B of the second embodiment, when the accelerator is off, the lockup of the torque converter is released when the rotational speed Ne of the engine 22 reaches a rotational speed slightly higher than the idle rotational speed (for example, 600 rpm).

  When the accelerator off time control routine is executed, the CPU 62 of the vehicle electronic control unit 60 first inputs data necessary for control such as the eco switch signal ESW from the eco switch 79 and the rotational speed Ne of the engine 22 (step S200), it is determined whether the input eco-switch signal ESW is on or off (step S210). Here, the rotation speed Ne of the engine 22 is calculated based on the crank position from the crank position sensor 23 and is input from the engine ECU 26 by communication. When the eco switch signal ESW is off, that is, when the driver is not giving an instruction to give priority to fuel consumption, the engine speed Ne is compared with the threshold value Nref1 (step S220), and the engine speed Ne is greater than or equal to the threshold value Nref1. Sometimes the fuel to the engine 22 is cut on the condition that other fuel cut conditions are satisfied (step S230), and this routine is terminated. When the rotational speed Ne of the engine 22 is less than the threshold value Nref1, the engine 22 is cut. Fuel injection is performed (step S240), and this routine is terminated. Here, the threshold value Nref1 is set as the rotational speed of the engine 22 that stops the fuel cut to the engine 22 and supplies the fuel to the engine 22 when the eco switch 79 is turned off, for example, 1800 rpm Or 1700 rpm can be used. Therefore, when the accelerator is turned off at a relatively high speed, the fuel cut of the engine 22 is performed. Thereafter, when the rotational speed Ne of the engine 22 reaches less than the threshold value Nref1, the fuel cut of the engine 22 is stopped and the engine 22 is cut. The fuel injection is resumed. Further, as the fuel cut condition, in addition to the above-described engine speed Ne being equal to or higher than the threshold value Nref1, the engine 22 has been warmed up, or a purification device attached to the exhaust pipe of the engine 22 It can be mentioned that the catalyst warm-up is complete. The fuel cut is performed by transmitting a fuel cut control signal to the engine ECU 26 and executing it based on the control signal received by the engine ECU 26.

  On the other hand, when it is determined in step S210 that the eco switch signal ESW is on, it is determined that the driver is giving an instruction to give priority to fuel consumption, and the rotational speed Ne of the engine 22 is compared with a threshold value Nref2 smaller than the threshold value Nref1 ( In step S250, when the rotational speed Ne is equal to or greater than the threshold value Nref2, the fuel to the engine 22 is cut on condition that another fuel cut condition is satisfied (step S260), and it is determined that the rotational speed Ne is less than the threshold value Nref2. If so, fuel is injected into the engine 22 (step S270), and this routine is terminated. Here, the threshold value Nref2 is set as the rotational speed of the engine 22 that stops fuel cut to the engine 22 and supplies fuel to the engine 22 when the eco switch 79 is on. For example, a value smaller than the threshold value Nref1 when 79 is turned off is, for example, about 400 prm or 500 rpm. Thus, when the eco switch 79 is turned on, the engine 22 that stops the fuel cut and restarts the fuel supply to the engine 22 is compared with the rotation speed of the engine 22 when the eco switch 79 is turned off. By reducing it, the duration of fuel cut of the engine 22 can be lengthened, and the fuel consumption of the vehicle can be further improved.

  FIG. 6 is an explanatory diagram showing an example of a change over time in the rotational speed Ne of the engine 22 and the fuel cut state of the engine 22 when the accelerator is off. As shown in the drawing, when the eco switch 79 is off, the fuel cut is turned off at time T2, but when the eco switch 79 is on, the fuel cut is turned off at time T3 later than time T2. That is, when the eco switch 79 is on, the fuel consumption is improved by delaying the time during which the fuel cut is turned off.

  According to the automobile 20B of the second embodiment described above, when the eco-switch 79 is on when the accelerator is off, the engine 22 is stopped at the fuel cut and the fuel supply to the engine 22 is resumed. Since the engine speed is smaller than that when the eco-switch 79 is turned off, the fuel cut duration of the engine 22 can be lengthened, and the dynamic characteristics of the vehicle may be slightly reduced. The fuel consumption of the vehicle can be further improved while ensuring the dynamic characteristics of the vehicle.

  In the automobile 20B of the second embodiment, the automatic stepped transmission 30B is mounted. However, a manual stepped transmission that shifts by a driver's shift operation may be mounted.

  In the embodiments, the best mode for carrying out the invention has been described as applied to the automobiles 20 and 20B. However, the invention is not limited to the automobiles 20 and 20B, and may be applied to vehicles other than automobiles. It is good also as a form of the control method of vehicles including a car.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the first embodiment, the engine 22 corresponds to an “internal combustion engine”, the eco switch 79 corresponds to a “fuel efficiency priority instruction switch”, the vehicle speed sensor 78 corresponds to “vehicle speed detection means”, and the eco switch 79 corresponds to an accelerator off state. Depending on the on / off state of the vehicle, the vehicle speed V is equal to or higher than the threshold value Vref1 and the threshold value Vref2, and the conditions such as the warming up of the engine 22 being completed and the catalyst warming up of the purification device being completed are satisfied. Step S120 of the accelerator-off time control routine of FIG. 2 that executes fuel cut of the engine 22 when the vehicle is running, and then resumes fuel supply to the engine 22 when the vehicle speed V reaches less than the threshold value Vref1 or the threshold value Vref2. The vehicular electronic control unit 60 that executes the process of S170 corresponds to “accelerator-off time control means”. The automatic continuously variable transmission 30 corresponds to “a continuously variable transmission means”. In the second embodiment, the engine 22 corresponds to an “internal combustion engine”, the eco switch 79 corresponds to a “fuel consumption priority instruction switch”, and the engine 22 is controlled based on the crank position sensor 23 and the crank position from the crank position sensor 23. The engine ECU 26 that calculates the rotational speed Ne corresponds to “rotational speed detection means”. When the accelerator is off, the rotational speed Ne of the engine 22 is greater than or equal to the threshold value Nref1 or the threshold value Nref2 depending on the on / off state of the eco switch 79. The fuel cut of the engine 22 is executed when conditions such as the warm-up of the engine 22 being completed and the catalyst warm-up of the purifier are completed, and then the rotational speed of the engine 22 is performed. When Ne reaches a threshold value Nref1 or less than a threshold value Nref2, fuel supply to the engine 22 is resumed. That a vehicle electronic control unit 60 executing the processing in steps S220~S270 of accelerator-off control routine of FIG. 5 corresponds to the "accelerator-off time control means". The automatic stepped transmission 30B corresponds to “stepped transmission means”. The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in the vehicle manufacturing industry.

It is a block diagram which shows the outline of a structure of the motor vehicle 20 as 1st Example of this invention. It is a flowchart which shows an example of the control routine at the time of the accelerator OFF performed by the vehicle electronic control unit 60 of 1st Example. It is explanatory drawing which shows an example of the time change of the vehicle speed V at the time of accelerator off, and the fuel cut state of the engine 22. FIG. It is a block diagram which shows the outline of a structure of the motor vehicle 20B of 2nd Example. It is a flowchart which shows an example of the control routine at the time of accelerator off performed by the vehicle electronic control unit 60 of 2nd Example. It is explanatory drawing which shows an example of the time change of the rotation speed Ne of the engine 22 at the time of an accelerator off, and the fuel cut state of the engine 22. FIG.

Explanation of symbols

  20, 20B Automobile, 22 Engine, 23 Crank position sensor, 24 Crankshaft, 26 Electronic control unit for engine (engine ECU), 30 Automatic continuously variable transmission, 30B Automatic stepped transmission, 32, 32B Electronic control for automatic transmission Unit (ATECU), 34 drive shaft, 36 differential gear, 38a, 38b drive wheel, 60 vehicle electronic control unit, 62 CPU, 64 ROM, 66 RAM, 68 timer, 70 ignition switch, 71 shift lever, 72 shift position sensor 73 Accelerator pedal, 74 Accelerator pedal position sensor, 75 Brake pedal, 76 Brake pedal position sensor, 78 Vehicle speed sensor, 79 Eco switch.

Claims (8)

A vehicle equipped with an internal combustion engine that outputs driving power,
A fuel efficiency priority instruction switch for instructing fuel efficiency priority;
Vehicle speed detection means for detecting the vehicle speed;
The internal combustion engine is configured such that when the accelerator is off, the fuel supply of the internal combustion engine is stopped when a predetermined fuel cut condition including a condition that the detected vehicle speed is equal to or higher than the vehicle speed based on the state of the fuel consumption priority instruction switch is satisfied. An accelerator off-time control means for controlling the engine and controlling the internal combustion engine to start the fuel supply when the predetermined fuel cut condition is not satisfied in a state where the fuel supply of the internal combustion engine is stopped;
A vehicle comprising:   The accelerator-off time control means uses the condition that the detected vehicle speed is equal to or higher than the first vehicle speed when the fuel consumption priority instruction switch is off when the accelerator is off as one of the predetermined fuel cut conditions. The internal combustion engine is controlled so that fuel supply is stopped and started, and the condition that the detected vehicle speed is equal to or higher than the second vehicle speed, which is smaller than the first vehicle speed, when the fuel consumption priority instruction switch is on when the accelerator is off. 2. The vehicle according to claim 1, wherein the vehicle is a means for controlling the internal combustion engine so that the fuel supply to the internal combustion engine is stopped and started using one of the predetermined fuel cut conditions. The vehicle according to claim 1 or 2,
Continuously variable transmission means for steplessly shifting the power on the output shaft side of the internal combustion engine and outputting it to the axle side;
The accelerator-off time control means is means for controlling the continuously variable transmission means so that the internal combustion engine rotates at a predetermined rotational speed when the accelerator is off.
vehicle. A vehicle equipped with an internal combustion engine that outputs driving power,
A fuel efficiency priority instruction switch for instructing fuel efficiency priority;
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
When the accelerator is off, the fuel supply of the internal combustion engine is stopped when a predetermined fuel cut condition including a condition that the detected rotational speed is equal to or higher than the rotational speed based on the state of the fuel consumption priority instruction switch is satisfied. Accelerator-off time control means for controlling the internal combustion engine and controlling the internal combustion engine to start fuel supply when the predetermined fuel cut condition is not satisfied in a state where the fuel supply of the internal combustion engine is stopped. When,
A vehicle comprising:   The accelerator off-time control means uses the condition that the detected rotational speed is equal to or higher than the first rotational speed when the fuel consumption priority instruction switch is off when the accelerator is off as one of the predetermined fuel cut conditions. The internal combustion engine is controlled so that the fuel supply of the engine is stopped and started. When the fuel efficiency priority instruction switch is on when the accelerator is off, the detected rotational speed is a second rotational speed that is smaller than the first rotational speed. 5. The vehicle according to claim 4, wherein said vehicle is means for controlling said internal combustion engine so that fuel supply to said internal combustion engine is stopped and started using one of said predetermined fuel cut conditions.   The vehicle according to claim 4 or 5, further comprising a stepped transmission means for shifting the power on the output shaft side of the internal combustion engine in a stepped manner and outputting it to the axle side. A vehicle control method comprising: an internal combustion engine that outputs power for traveling; and a fuel efficiency priority instruction switch that instructs fuel efficiency priority,
The internal combustion engine is configured such that when the fuel efficiency priority instruction switch is off when the accelerator is off, the fuel supply of the internal combustion engine is stopped when a first fuel cut condition including a condition that the vehicle speed is equal to or higher than the first vehicle speed is satisfied. And controlling the internal combustion engine to start fuel supply when the first fuel cut condition is not established in a state where the fuel supply of the internal combustion engine is stopped, and the fuel consumption priority is given when the accelerator is off. The internal combustion engine is configured such that when the instruction switch is on, the fuel supply of the internal combustion engine is stopped when a second fuel cut condition including a condition that the vehicle speed is equal to or higher than a second vehicle speed that is smaller than the first vehicle speed is satisfied. The internal combustion engine so that the fuel supply is started when the second fuel cut condition is not established in a state where the fuel supply of the internal combustion engine is stopped. To control,
A method for controlling a vehicle. A vehicle control method comprising: an internal combustion engine that outputs power for traveling; and a fuel efficiency priority instruction switch that instructs fuel efficiency priority,
When the fuel efficiency priority instruction switch is off when the accelerator is off, the fuel supply to the internal combustion engine is stopped when a first fuel cut condition including a condition that the rotational speed of the internal combustion engine is equal to or higher than the first rotational speed is satisfied. Controlling the internal combustion engine and controlling the internal combustion engine to start fuel supply when the first fuel cut condition is not satisfied in a state where the fuel supply of the internal combustion engine is stopped. When the fuel efficiency priority instruction switch is on when the accelerator is off, the internal combustion engine satisfies a second fuel cut condition including a condition that the rotational speed of the internal combustion engine is equal to or higher than a second rotational speed that is smaller than the first rotational speed. The internal combustion engine is controlled so that the fuel supply of the engine is stopped, and the second fuel cut condition is not satisfied in a state where the fuel supply of the internal combustion engine is stopped. Controlling the internal combustion engine to start fuel supply in,
A method for controlling a vehicle.

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