JP2008120295A - Vehicle and control method thereof - Google Patents

Abstract

A good relationship between fuel efficiency of a vehicle and air conditioning of a passenger compartment in response to a fuel efficiency priority instruction is ensured.
When the eco-switch is turned on when the accelerator is off, the load (duty ratio) of the compressor of the air conditioner is set to 100% during the engine fuel cut (S250), and the vehicle speed V Is less than the threshold value Vref4 that is smaller than the threshold value Vref3 when the eco switch is off, the compressor load (duty ratio) of the air conditioner is set to 0% (S260). As a result, it is possible to lengthen the duration for which the load (duty ratio) of the compressor is 100% as compared with when the eco switch is off, and more kinetic energy of the vehicle can be stored in the refrigeration cycle. . As a result, although the comfort in the air conditioning of the passenger compartment may be slightly impaired, the fuel consumption of the vehicle can be improved.
[Selection] Figure 2

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, a vehicle that operates a compressor of a vehicle cooling device while cutting fuel to an engine during deceleration of the vehicle has been proposed (see, for example, Patent Document 1). In this vehicle, a part of the kinetic energy during cutting of fuel to the engine is regenerated by operating the compressor, thereby improving the fuel efficiency of the vehicle.
JP 2003-165331 A

  As an example of the above-mentioned vehicle, the fuel efficiency of the vehicle can be improved by driving the air conditioner while the fuel to the engine is cut, but in some cases, The passenger compartment may be overcooled. This is good when the occupant wants to prioritize fuel economy over air conditioning in the occupant room, but not when the passengers want comfort in the passenger compartment. Further, although it is necessary for the vehicle to improve the fuel consumption and to ensure good dynamic characteristics of the vehicle, 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. In view of these demands, some vehicles are provided with a switch for instructing priority on fuel efficiency, and a good relationship between passenger compartment comfort, vehicle dynamics, and fuel efficiency is desired.

  One object of the vehicle and its control method of the present invention is to ensure a good relationship between the fuel consumption of the vehicle and the air conditioning of the passenger compartment in response to the fuel efficiency priority instruction. Another object of the vehicle and the control method thereof according to the present invention is to improve the fuel efficiency while ensuring the necessary vehicle dynamic characteristics 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 at least a part of the above-described object.

The vehicle of the present invention
A vehicle equipped with an internal combustion engine that outputs driving power,
An air conditioner for air conditioning the passenger compartment using the power of the output shaft of the internal combustion engine;
A fuel efficiency priority instruction switch for instructing fuel efficiency priority;
When the accelerator is off, the internal combustion engine is controlled so that the fuel supply to the internal combustion engine is stopped when a predetermined fuel cut condition is satisfied, and the predetermined fuel cut condition is maintained while the fuel supply to the internal combustion engine is stopped. The internal combustion engine is controlled to start fuel supply when a fuel cut condition is not established, and the fuel consumption priority instruction switch is within the range where the fuel supply of the internal combustion engine is stopped based on the state of the fuel consumption priority instruction switch. An accelerator-off time control means for controlling the air conditioner so that the air conditioner operates at a predetermined load;
It is a summary to provide.

  In the vehicle of the present invention, when the accelerator is off, the internal combustion engine is controlled so that the fuel supply of the internal combustion engine is stopped when the predetermined fuel cut condition is satisfied, and then the predetermined fuel cut condition is not satisfied. The internal combustion engine is controlled so that the fuel supply is started. Then, the air conditioner is controlled so that the air conditioner operates at a predetermined load based on the state of the fuel efficiency priority instruction switch within the range where the fuel supply of the internal combustion engine is stopped. Thereby, the relationship between the improvement of the fuel consumption of the vehicle and the air conditioning of the passenger compartment can be changed according to the state of the fuel consumption priority instruction switch, and the favorable relationship between the fuel consumption of the vehicle and the air conditioning of the passenger compartment with respect to the fuel consumption priority indication Can be secured.

  In such a vehicle of the present invention, the accelerator-off time control means is configured such that the time during which the air conditioner operates at the predetermined load is greater when the fuel efficiency priority instruction switch is on than when the fuel efficiency priority instruction switch is off. It can also be a means for controlling the air conditioner to be long. In this way, by turning on the fuel efficiency priority instruction switch, the fuel efficiency of the vehicle can be improved although the comfort of the passenger compartment is slightly impaired.

  The vehicle according to the present invention further includes vehicle speed detecting means for detecting a vehicle speed, wherein the accelerator-off time control means is configured to detect when the detected vehicle speed is less than the first vehicle speed when the fuel consumption priority instruction switch is off. The air conditioner is controlled to stop operating at the predetermined load, and when the fuel consumption priority instruction switch is on, the detected vehicle speed is less than the second vehicle speed which is less than the first vehicle speed. The air conditioner may be a means for controlling the air conditioner to stop operating at the predetermined load. If it carries out like this, it can stop operating an air-conditioner with predetermined load using vehicle speed.

  In the vehicle of the present invention in which the air conditioner stops operating at a predetermined load based on the vehicle speed, the accelerator-off time control means is detected when the fuel consumption priority instruction switch is off when the accelerator is off. 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 as a condition that the vehicle speed is equal to or higher than a third vehicle speed smaller than the first vehicle speed; The fuel supply of the internal combustion engine is performed by using, as one of the predetermined fuel cut conditions, a condition that the detected vehicle speed is equal to or higher than a fourth vehicle speed that is smaller than the second vehicle speed when the fuel efficiency priority instruction switch is on when the accelerator is off. The internal combustion engine may be controlled to be stopped and started. If it carries out like this, a fuel cut can be performed according to the state of a fuel consumption priority instruction | indication switch, and the fuel supply to an 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.

  Further, in the vehicle of the present invention in which the air conditioner is stopped from operating at a predetermined load based on the vehicle speed, the continuously variable power is output to the axle side by continuously changing the power on the output shaft side of the internal combustion engine. The accelerator-off-time control means may be 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.

  The vehicle according to the present invention further includes a rotational speed detection means for detecting the rotational speed of the internal combustion engine, and the accelerator-off time control means is configured such that the detected rotational speed is a first rotational speed when the fuel consumption priority instruction switch is off. The air conditioner is controlled to stop operating at the predetermined load when it reaches less than the predetermined load, and when the fuel consumption priority instruction switch is on, the detected rotational speed is the first rotational speed. The air conditioner may be a means for controlling the air conditioner to stop operating at the predetermined load when it reaches a smaller second rotation speed. If it carries out like this, it can stop operating an air conditioner with a predetermined load using the number of rotations of an internal-combustion engine.

  In the vehicle of the present invention in which the air conditioner is stopped from operating at a predetermined load based on the rotational speed of the internal combustion engine, the accelerator-off time control means is configured such that when the fuel consumption priority instruction switch is off when the accelerator is off. The fuel supply to the internal combustion engine is stopped and started by using, as one of the predetermined fuel cut conditions, a condition in which the detected rotational speed is equal to or higher than a third rotational speed that is smaller than the first rotational speed. One of the predetermined fuel cut conditions is a condition in which the internal combustion engine is controlled, and when the fuel consumption priority instruction switch is on when the accelerator is off, the detected rotational speed is equal to or higher than a fourth rotational speed that is smaller than the second rotational speed. It can also be used as means for controlling the internal combustion engine so that the fuel supply to the internal combustion engine is stopped and started. If it carries out like this, a fuel cut can be performed according to the state of a fuel consumption priority instruction | indication switch, and the fuel supply to an 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.

  Further, in the vehicle of the present invention in which the air conditioner is stopped from operating at a predetermined load based on the rotational speed of the internal combustion engine, the power on the output shaft side of the internal combustion engine is shifted stepwise to the axle side. A stepped transmission means for outputting may be provided.

The vehicle control method of the present invention includes:
A vehicle control method comprising: an internal combustion engine that outputs power for traveling; an air conditioner that performs air conditioning of a passenger compartment using power of an output shaft of the internal combustion engine; and a fuel efficiency priority instruction switch that instructs fuel efficiency priority Because
When the accelerator is off, the internal combustion engine is controlled so that the fuel supply to the internal combustion engine is stopped when a predetermined fuel cut condition is satisfied, and the predetermined fuel cut condition is maintained while the fuel supply to the internal combustion engine is stopped. The internal combustion engine is controlled to start fuel supply when a fuel cut condition is not established, and the fuel consumption priority instruction switch is turned on within a range where the fuel supply of the internal combustion engine is stopped. Controlling the air conditioner so that it takes a longer time for the air conditioner to operate at a predetermined load than when the priority instruction switch is off;
It is characterized by that.

  In the vehicle control method of the present invention, when the accelerator is off, the internal combustion engine is controlled so that the fuel supply of the internal combustion engine is stopped when the predetermined fuel cut condition is satisfied, and then the predetermined fuel cut condition is satisfied. The internal combustion engine is controlled to start the fuel supply when it is not established. When the fuel consumption priority instruction switch is on within the range where the fuel supply of the internal combustion engine is stopped, the time during which the air conditioner operates at a predetermined load is longer than when the fuel consumption priority instruction switch is off. Control the air conditioner. As a result, when the fuel efficiency priority instruction switch is on, the vehicle fuel efficiency can be improved, although the comfort of the passenger compartment is slightly impaired as compared to when the fuel efficiency priority instruction switch is off. As a result, it is possible to ensure a good relationship between the fuel consumption of the vehicle and the air conditioning of the passenger compartment with respect to the fuel efficiency priority instruction.

  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. An automatic continuously variable transmission 30 that can change the speed of the vehicle, an air conditioner 50 that performs air conditioning of the passenger compartment 21, 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 air conditioner 50 includes a compressor 52 attached to the crankshaft 24 of the engine 22 via a belt 28 via a clutch 53, a refrigeration cycle 51 including a condenser, an expansion valve, and an evaporator (not shown), and heat generated by the evaporator of the refrigeration cycle 51. A blower 54 for blowing the air cooled by the exchange to the air outlet 21a of the passenger compartment 21, an operation panel 55 attached to the passenger compartment 21, and an air conditioning electronic control unit (hereinafter referred to as an air conditioning ECU) for controlling the entire apparatus. 58. The air conditioning ECU 58 includes a blower switch signal BSW from a blower switch 56a which is attached to the operation panel 55 and operates on / off of cooling, and a set temperature switch 56b which is also attached to the operation panel 55 and sets the temperature in the passenger compartment 21. Set temperature T *, a passenger room temperature Tin that is attached to the operation panel 55 and detects a temperature in the passenger compartment 21 is input, and the air conditioning ECU 58 drives the compressor 52 and the clutch 53. A signal is being output. The air conditioning ECU 58 drives and controls the compressor 52 and the blower 54 so that the passenger room temperature Tin becomes the set temperature T * based on the input signal. Further, the air conditioning ECU 58 communicates with the vehicle electronic control unit 60, and transmits data related to the state of the air conditioner 50 to the vehicle electronic control unit 60 and controls from the vehicle electronic control unit 60 as necessary. Receive a signal.

  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, the ATECU 32, and the air conditioning ECU 58 via a communication port, and exchanges various control signals and data with the engine ECU 26, the ATECU 32, and the air conditioning ECU 58.

  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 giving an instruction to give priority to fuel consumption, the vehicle speed V is compared with the threshold value Vref3 (step S120). When the vehicle speed V is equal to or higher than the threshold value Vref3, other fuels are compared. Fuel for the engine 22 is cut on condition that the cutting condition is satisfied (step S130). Here, the threshold value Vref3 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. Further, as the fuel cut condition, in addition to the above-described vehicle speed V being equal to or higher than the threshold value Vref3, 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. In the accelerator off time control routine of FIG. 2, the fuel cut condition other than the vehicle speed V is assumed to be satisfied. 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. Subsequently, the vehicle speed V is compared with a threshold value Vref1 larger than the threshold value Vref3 (step S140). When the vehicle speed V is equal to or higher than the threshold value Vref1, the clutch 53 is not connected and the load (duty ratio) of the compressor 52 of the air conditioner 50 is connected. ) Is set to 100% (step S150), this routine is terminated. When the vehicle speed V is less than the threshold value Vref1, the clutch 53 is turned off and the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 0% (step S160). This routine ends. Here, the threshold value Vref1 is a threshold value for determining whether or not to end the operation of increasing the load on the compressor 52 when the eco switch 79 is turned off. For example, the threshold value Vref1 is 25 km / h or 20 km / h. Etc. can be used. If the load on the compressor 52 is increased while the fuel cut of the engine 22 is being performed in this way, a part of the kinetic energy of the vehicle can be stored in the refrigeration cycle 51 of the air conditioner 50, so that the entire vehicle As a result, fuel consumption can be improved. To change the load (duty ratio) of the compressor 52 to 100% or 0%, the control signal is transmitted to the air conditioning ECU 58, and the clutch 53 and the compressor 52 are driven based on the control signal received by the air conditioning ECU 58. It is done by. If it is determined in step S120 that the vehicle speed V is less than the threshold value Vref3, fuel is injected into the engine 22 (step S170), and this routine is terminated. With the above processing, when the accelerator is turned off at a relatively high speed, the fuel cut of the engine 22 is performed. When the vehicle speed V reaches less than the threshold value Vref3, the fuel cut of the engine 22 is stopped and the fuel is injected into the engine 22. Is resumed. During the fuel cut of the engine 22, the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 100% until the vehicle speed V becomes less than the threshold value Vref1 larger than the threshold value Vref3 at which the fuel cut is stopped.

  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 Vref4 that is smaller than the threshold value Vref3 (step S220). When the vehicle speed V is equal to or higher than the threshold value Vref4, the fuel to the engine 22 is cut on condition that other fuel cut conditions are satisfied (step S230). Here, the threshold value Vref4 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 Vref3. 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. Subsequently, the vehicle speed V is compared with a threshold value Vref2 smaller than the threshold value Vref1 (step S240). When the vehicle speed V is equal to or higher than the threshold value Vref2, the clutch 53 is not connected and the load (duty ratio) of the compressor 52 of the air conditioner 50 is connected. ) Is set to 100% (step S250), and this routine is terminated. When the vehicle speed V is less than the threshold value Vref2, the clutch 53 is turned off and the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 0% (step S260). This routine ends. Here, the threshold value Vref2 is a threshold value for determining whether or not to end the operation of increasing the load of the compressor 52 when the eco switch 79 is on, and the eco switch 79 is off. For example, a value smaller than the threshold value Vref1 such as 5 km / h or 10 km / h is used. Thus, by reducing the vehicle speed at which the operation of increasing the load of the compressor 52 when the eco switch 79 is turned on is smaller than when the eco switch 79 is turned off, the compressor 52 The driving time can be increased by setting the load (duty ratio) to 100%, and more of the kinetic energy of the vehicle can be stored in the refrigeration cycle. As a result, the fuel consumption of the vehicle can be further improved. If it is determined in step S220 that the vehicle speed V is less than the threshold value Vref4, fuel is injected into the engine 22 (step S270), and this routine is terminated. By the above processing, when the accelerator is turned off at a relatively high speed, the fuel cut of the engine 22 is performed, and when the vehicle speed V reaches the threshold value Vref4 which is smaller than the threshold value Vref3, the fuel cut of the engine 22 is stopped and the engine 22 is stopped. The fuel injection to is resumed. During the fuel cut of the engine 22, the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 100% until the vehicle speed V becomes less than the threshold value Vref2 that is smaller than the threshold value Vref1. Thereby, when the eco switch 79 is turned on, the comfort in the air conditioning of the passenger compartment 21 may be slightly impaired, but the fuel efficiency of the vehicle can be improved.

  FIG. 3 is an explanatory diagram showing an example of a temporal change in the vehicle speed V when the accelerator is off, the fuel cut state of the engine 22, and the load (duty ratio) of the compressor 52 of the air conditioner 50. As shown in the figure, when the eco switch 79 is off, the load (duty ratio) of the compressor 52 is set to 0% at time T2 and the fuel cut is turned off at time T4. However, when the eco switch 79 is on, it is later than the time T2. At time T3, the load (duty ratio) of the compressor 52 is set to 0%, and the fuel cut is turned off at time T5 later than time T4. That is, when the eco switch 79 is on, both the time for setting the load (duty ratio) of the compressor 52 to 0% and the time for turning off the fuel cut are delayed, and fuel efficiency can be improved accordingly.

  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 load on the compressor 52 of the air conditioner 50 is increased during the fuel cut of the engine 22. Since the vehicle speed at which the operation is stopped is set to a lower vehicle speed than when the eco switch 79 is off when the accelerator is off, the duration of the operation to increase the load on the compressor 52 can be lengthened. More kinetic energy can be stored in the refrigeration cycle. As a result, the comfort in the air conditioning of the passenger compartment 21 may be slightly impaired, but the fuel efficiency of the vehicle can be improved. That is, it is possible to ensure a good relationship between the fuel consumption of the vehicle and the air conditioning of the passenger compartment in response to the fuel efficiency priority instruction. Moreover, when the eco switch 79 is 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 smaller than when the eco switch 79 is off. Since the vehicle speed is set, the fuel cut duration of the engine 22 can be lengthened and the vehicle dynamic characteristics may be slightly reduced, but the vehicle fuel efficiency can be further improved. That is, it is possible to ensure a good relationship between the vehicle dynamic characteristics in response to the fuel efficiency priority instruction, the vehicle fuel efficiency, and the passenger compartment air conditioning.

  In the automobile 20 of the first embodiment, when the eco switch 79 is turned on when the accelerator is off, the eco switch 79 sets the vehicle speed (threshold Vref4) at which the fuel cut of the engine 22 is stopped and the fuel supply to the engine 22 is resumed. Although the vehicle speed is lower than the vehicle speed (threshold value Vref3) when it is turned off, the fuel cut of the engine 22 is stopped at the same vehicle speed (for example, the threshold value Vref3) regardless of whether the eco switch 79 is turned on or off, and fuel is supplied to the engine 22. The supply may be resumed.

  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 S300), it is determined whether the input eco-switch signal ESW is on or off (step S310). 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 Nref3 (step S320), and the engine speed Ne is equal to or greater than the threshold value Nref3. Sometimes, fuel to the engine 22 is cut on condition that other fuel cut conditions are satisfied (step S330). Here, the threshold value Nref3 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. As the fuel cut condition, as described in the first embodiment, in addition to the above-described engine speed Ne being equal to or higher than the threshold value Nref3, the engine 22 has been warmed up or the engine 22 It can be mentioned that the catalyst warm-up of the purification device attached to the exhaust pipe is completed. In the accelerator-off control routine of FIG. 5, the description will be made on the assumption that such fuel cut conditions other than the rotational speed Ne of the engine 22 are satisfied. Subsequently, the rotational speed Ne of the engine 22 is compared with a threshold value Nref1 greater than the threshold value Nref3 (step S340). When the rotational speed Ne is equal to or greater than the threshold value Nref1, the clutch 53 is connected when not connected, and the compressor 52 of the air conditioner 50 is connected. The load (duty ratio) is set to 100% (step S350), and this routine is terminated. When the rotational speed Ne is less than the threshold value Nref1, the clutch 53 is turned off and the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 0%. (Step S360), and this routine ends. Here, the threshold value Nref1 is a threshold value for determining whether or not to end the operation of increasing the load of the compressor 52 when the eco switch 79 is turned off. For example, 2000 rpm or 1900 rpm is used. Can do. If the load on the compressor 52 is increased while the fuel cut of the engine 22 is being performed in this way, a part of the kinetic energy of the vehicle can be stored in the refrigeration cycle 51 of the air conditioner 50, so that the entire vehicle As a result, fuel consumption can be improved. If it is determined in step S320 that the rotational speed Ne of the engine 22 is less than the threshold value Nref3, fuel is injected into the engine 22 (step S370), and this routine is terminated. With the above processing, when the accelerator is turned off at a relatively high speed, the fuel cut of the engine 22 is performed, and when the rotational speed Ne of the engine 22 reaches less than the threshold value Nref3, the fuel cut of the engine 22 is stopped and the engine 22 is cut off. The fuel injection to is resumed. During the fuel cut of the engine 22, the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 100% until the rotational speed Ne of the engine 22 becomes less than the threshold value Nref1 larger than the threshold value Nref3 for stopping the fuel cut. .

  On the other hand, when it is determined in step S310 that the eco switch signal ESW is on, it is determined that the driver is giving an instruction to give priority to fuel efficiency, and the rotational speed Ne of the engine 22 is compared with a threshold value Nref4 that is smaller than the threshold value Nref3 ( In step S420), when the rotational speed Ne is equal to or greater than the threshold value Nref4, the fuel to the engine 22 is cut on condition that another fuel cut condition is satisfied (step S430). Here, the threshold value Nref4 is set as the rotational speed of the engine 22 that stops the fuel cut to the engine 22 and supplies fuel to the engine 22 when the eco switch 79 is turned on. For example, a value smaller than the threshold value Nref3 when 79 is turned off is 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. Subsequently, the rotational speed Ne of the engine 22 is compared with a threshold value Nref2 smaller than the threshold value Nref1 (step S440). When the rotational speed Ne is equal to or greater than the threshold value Nref2, the clutch 53 is connected when it is not connected, and the compressor 52 of the air conditioner 50 is connected. The load (duty ratio) is set to 100% (step S450), and this routine is terminated. When the rotational speed Ne is less than the threshold value Nref2, the clutch 53 is turned off and the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 0%. (Step S460), and this routine ends. Here, the threshold value Nref2 is a threshold value for determining whether or not to end the operation of increasing the load on the compressor 52 when the eco switch 79 is on, and the eco switch 79 is off. For example, a value smaller than the threshold value Nref1 by about 400 rpm or 500 rpm is used. In this way, by reducing the rotational speed of the engine 22 that ends the operation of increasing the load of the compressor 52 when the eco switch 79 is on, compared to when the eco switch 79 is off. Further, the driving duration time can be increased by setting the load (duty ratio) of the compressor 52 to 100%, and more kinetic energy of the vehicle can be stored in the refrigeration cycle. As a result, the fuel consumption of the vehicle can be further improved. When it is determined in step S420 that the rotational speed Ne of the engine 22 is less than the threshold value Nref4, fuel is injected into the engine 22 (step S470), and this routine is terminated. With the above processing, when the accelerator is turned off at a relatively high speed, the fuel cut of the engine 22 is performed, and when the rotational speed Ne of the engine 22 becomes less than the threshold value Nref4 smaller than the threshold value Nref3, the fuel cut of the engine 22 is stopped. Thus, fuel injection into the engine 22 is resumed. During the fuel cut of the engine 22, the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 100% until the rotational speed Ne of the engine 22 reaches a value less than the threshold value Nref2 smaller than the threshold value Nref1. Thereby, when the eco switch 79 is turned on, the comfort in the air conditioning of the passenger compartment 21 may be slightly impaired, but the fuel efficiency of the vehicle can be improved.

  FIG. 6 is an explanatory diagram showing an example of a change over time in the rotational speed Ne of the engine 22 when the accelerator is off, the fuel cut state of the engine 22, and the load (duty ratio) of the compressor 52 of the air conditioner 50. As shown in the figure, when the eco switch 79 is off, the load (duty ratio) of the compressor 52 is set to 0% at time T2 and the fuel cut is turned off at time T4. However, when the eco switch 79 is on, it is later than the time T2. At time T3, the load (duty ratio) of the compressor 52 is set to 0%, and the fuel cut is turned off at time T5 later than time T4. That is, when the eco switch 79 is on, both the time for setting the load (duty ratio) of the compressor 52 to 0% and the time for turning off the fuel cut are delayed, and fuel efficiency can be improved accordingly.

  According to the automobile 20B of the second embodiment described above, when the eco switch 79 is turned on when the accelerator is off, the load on the compressor 52 of the air conditioner 50 during the fuel cut of the engine 22 is increased. Since the rotational speed of the engine 22 that stops the operation is set to a smaller rotational speed than when the eco switch 79 is off when the accelerator is off, the duration of the operation that increases the load on the compressor 52 is lengthened. And more of the kinetic energy of the vehicle can be stored in the refrigeration cycle. As a result, the comfort in the air conditioning of the passenger compartment 21 may be slightly impaired, but the fuel efficiency of the vehicle can be improved. That is, it is possible to ensure a good relationship between the fuel consumption of the vehicle and the air conditioning of the passenger compartment in response to the fuel efficiency priority instruction. Moreover, when the eco switch 79 is turned on when the accelerator is off, the fuel cut of the engine 22 is stopped and the fuel supply to the engine 22 is resumed. When the eco switch 79 is turned off, Since the engine speed is smaller than that of the engine 22, the fuel cut duration of the engine 22 can be lengthened, and the vehicle dynamic characteristics can be slightly reduced, but the vehicle fuel efficiency can be further improved. That is, it is possible to ensure a good relationship between the vehicle dynamic characteristics in response to the fuel efficiency priority instruction, the vehicle fuel efficiency, and the passenger compartment air conditioning.

  In the automobile 20B of the second embodiment, when the eco switch 79 is turned on when the accelerator is off, the engine 22 is stopped when the fuel cut is stopped and the fuel supply to the engine 22 is resumed (threshold Nref4). Although the engine speed is smaller than the engine speed (threshold value Nref3) when the eco switch 79 is turned off, the engine is operated at the same engine speed (eg, threshold value Vref3) regardless of whether the eco switch 79 is on or off. The fuel cut at 22 may be stopped and the fuel supply to the engine 22 may be resumed.

  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 automobile 20 of the first embodiment and the automobile 20B of the second embodiment, the load (duty ratio) of the compressor of the air conditioner is set to 100% while the engine fuel is being cut, and then the vehicle speed V is a threshold value. The compressor load (duty ratio) of the air conditioner is assumed to be 0% when Vref3 or the threshold value Vref4 is reached, but the compressor load (duty ratio) is not limited to 100% and 0%. Instead, various values can be used, such as 90% or 80% instead of 100%, or 5% or 10% instead of 0%.

  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 air conditioner 50 corresponds to an “air conditioner”, the eco switch 79 corresponds to a “fuel efficiency priority instruction switch”, and the vehicle speed V is a threshold value when the accelerator is off. The fuel cut of the engine 22 is executed when a condition such as Vref3 or the threshold value Vref4 or more and the warming up of the engine 22 being completed or the catalyst warming up of the purification device being completed is satisfied. At the same time, the processing of steps S120, S130, S170, S220, S230, and S270 of the accelerator-off time control routine of FIG. 2 that resumes fuel supply to the engine 22 when the vehicle speed V reaches the threshold value Vref3 or less than the threshold value Vref4. And when the fuel cut of the engine 22 is being performed, the air conditioner 50 is turned on or off according to the on / off state of the eco switch 79. The vehicle electronic control unit 60 that executes the processing of steps S140 to S160 and S240 to S260 of the accelerator off-time control routine of FIG. 2 for setting the load (duty ratio) of the presser 52 to 100% or 0% is shown in FIG. It corresponds to “control means”. The vehicle speed sensor 78 corresponds to “vehicle speed detection means”, and the automatic continuously variable transmission 30 corresponds to “continuously variable transmission means”. In the second embodiment, the engine 22 corresponds to an “internal combustion engine”, the air conditioner 50 corresponds to an “air conditioner”, the eco switch 79 corresponds to a “fuel efficiency priority instruction switch”, and the engine 22 rotates when the accelerator is off. When the number Ne is equal to or greater than the threshold value Nref3 or the threshold value Nref4 and the conditions such as the warming up of the engine 22 being completed and the catalyst warming up of the purifier being completed are satisfied, the fuel of the engine 22 Steps S320, S330, and S370 of the accelerator-off time control routine of FIG. 5 that executes the cut and then restarts the fuel supply to the engine 22 when the rotational speed Ne of the engine 22 reaches the threshold value Nref3 or less than the threshold value Nref4. , S420, S430, S470, and the eco switch 7 in the state where the fuel cut of the engine 22 is performed. For the vehicle to execute the processing of steps S340 to S360 and S440 to S460 of the accelerator off time control routine of FIG. 5 in which the load (duty ratio) of the compressor 52 of the air conditioner 50 is set to 100% or 0% according to the on / off state The electronic control unit 60 corresponds to “accelerator off time control means”. Further, the engine ECU 26 that calculates the rotational speed Ne of the engine 22 based on the crank position from the crank position sensor 23 and the crank position sensor 23 corresponds to “rotational speed detection means”, and the automatic stepped transmission 30B includes “existence”. Corresponds to a “step shifting 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, the fuel cut state of the engine 22, and the load (duty ratio) of the compressor 52 of the air conditioner 50. 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, the state of the fuel cut of the engine 22, and the load (duty ratio) of the compressor 52 of the air conditioner 50.

Explanation of symbols

  20, 20B Automobile, 21 Passenger compartment, 21a Outlet, 22 Engine, 23 Crank position sensor, 24 Crankshaft, 26 Engine electronic control unit (engine ECU), 28 Belt, 30 Automatic continuously variable transmission, 30B Automatic stepped Transmission, 32, 32B Automatic transmission electronic control unit (ATECU), 34 Drive shaft, 36 Differential gear, 38a, 38b Drive wheel, 50 Air conditioner, 51 Refrigeration cycle, 52 Compressor, 53 Clutch, 54 Blower, 55 Operation panel 56a Blower switch, 56b Set temperature switch, 56c Temperature sensor, 58 Air conditioning electronic control unit (air conditioning ECU), 60 Vehicle electronic control unit, 62 CPU, 64 ROM, 66 RAM, 68 Thailand 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 (9)

A vehicle equipped with an internal combustion engine that outputs driving power,
An air conditioner for air conditioning the passenger compartment using the power of the output shaft of the internal combustion engine;
A fuel efficiency priority instruction switch for instructing fuel efficiency priority;
When the accelerator is off, the internal combustion engine is controlled so that the fuel supply to the internal combustion engine is stopped when a predetermined fuel cut condition is satisfied, and the predetermined fuel cut condition is maintained while the fuel supply to the internal combustion engine is stopped. The internal combustion engine is controlled to start fuel supply when a fuel cut condition is not established, and the fuel consumption priority instruction switch is within the range where the fuel supply of the internal combustion engine is stopped based on the state of the fuel consumption priority instruction switch. An accelerator-off time control means for controlling the air conditioner so that the air conditioner operates at a predetermined load;
A vehicle comprising:   The accelerator-off-time control means controls the air conditioner so that the time during which the air conditioner operates at the predetermined load is longer when the fuel efficiency priority instruction switch is on than when the fuel efficiency priority instruction switch is off. 2. The vehicle according to claim 1, which is means for controlling. The vehicle according to claim 1 or 2,
Vehicle speed detection means for detecting the vehicle speed,
The accelerator-off-time control means is configured to stop the air conditioner from operating at the predetermined load when the detected vehicle speed is less than the first vehicle speed when the fuel efficiency priority instruction switch is off. When the fuel consumption priority instruction switch is on, the air conditioner stops operating at the predetermined load when the detected vehicle speed is less than the second vehicle speed which is smaller than the first vehicle speed. Means for controlling the air conditioner,
vehicle.   The accelerator-off-time control means uses, as one of the predetermined fuel cut conditions, a condition that the detected vehicle speed is equal to or higher than a third vehicle speed that is smaller than the first vehicle speed when the fuel consumption priority instruction switch is off when the accelerator is off. And controlling the internal combustion engine to stop and start the fuel supply of the internal combustion engine, and when the fuel consumption priority instruction switch is on when the accelerator is off, the detected vehicle speed is lower than the second vehicle speed. 4. The vehicle according to claim 3, 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 as a condition equal to or higher than a vehicle speed. The vehicle according to claim 3 or 4,
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. The vehicle according to claim 1 or 2,
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
The accelerator-off time control means is configured to stop the air conditioner from operating at the predetermined load when the detected speed is less than the first speed when the fuel efficiency priority instruction switch is off. The air conditioner is operated at the predetermined load when the air conditioner is controlled, and when the fuel consumption priority instruction switch is on, the detected rotation speed is less than a second rotation speed smaller than the first rotation speed. Means for controlling the air conditioner to stop doing,
vehicle.   The accelerator-off time control means sets a condition that the detected speed is equal to or greater than a third speed smaller than the first speed when the fuel efficiency 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 when the fuel efficiency priority instruction switch is on when the accelerator is off, the detected rotational speed is the second rotation. A means for controlling the internal combustion engine to stop and start the fuel supply of the internal combustion engine using a condition that is equal to or higher than a fourth rotation speed smaller than a number as one of the predetermined fuel cut conditions. 6. The vehicle according to 6.   The vehicle according to claim 6 or 7, further comprising 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; an air conditioner that performs air conditioning of a passenger compartment using power of an output shaft of the internal combustion engine; and a fuel efficiency priority instruction switch that instructs fuel efficiency priority Because
When the accelerator is off, the internal combustion engine is controlled so that the fuel supply to the internal combustion engine is stopped when a predetermined fuel cut condition is satisfied, and the predetermined fuel cut condition is maintained while the fuel supply to the internal combustion engine is stopped. The internal combustion engine is controlled to start fuel supply when a fuel cut condition is not established, and the fuel consumption priority instruction switch is turned on within a range where the fuel supply of the internal combustion engine is stopped. Controlling the air conditioner so that it takes a longer time for the air conditioner to operate at a predetermined load than when the priority instruction switch is off;
A method for controlling a vehicle.

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