JP2018103739A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle capable of avoiding excessive EV travelling and improving fuel economy.SOLUTION: An ECU of a hybrid vehicle stores a past travelling condition, and restricts EV travelling (Step S33) in which travelling is performed by the power of an ISG in a state that an operation of an engine is stopped based on the past travelling condition (Steps S31 and S32). The ECU restricts the EV travelling based on an experience vehicle speed (Step S31), which is a vehicle speed experienced in the past. The ECU restricts the EV travelling based on the number of times of EV experiences (Step S32), which is the number of times of the EV travelling performed in the past.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a hybrid vehicle.

  A conventional hybrid vehicle described in Patent Document 1 is known. The hybrid vehicle described in Patent Document 1 applies rotational driving force from the electric motor to the output shaft or axle of the internal combustion engine when the vehicle travels on the coast. In addition, the hybrid vehicle described in Patent Document 1 determines the magnitude of the output of the motor or whether to apply the rotational driving force from the motor during coasting, the speed of the vehicle, the deceleration of the vehicle or the slope of the road surface, The change is made in accordance with at least one of the transmission gear ratios interposed between the output shaft and the axle of the internal combustion engine.

  According to the hybrid vehicle described in Patent Literature 1, energy efficiency during coasting can be further improved, and drivability can be improved.

JP 2006-094161 A

  However, the one described in Patent Document 1 does not determine whether or not to apply the rotational driving force from the electric motor in consideration of the fuel efficiency, and the fuel efficiency is deteriorated by excessively performing the assist or EV traveling by the electric motor. There was a fear.

  The present invention has been made paying attention to the above-described problems, and an object of the present invention is to provide a hybrid vehicle that can avoid excessive EV travel and improve fuel efficiency.

  The present invention is an internal combustion engine, a motor generator connected to the output shaft of the internal combustion engine, having an electric function for generating power to be transmitted to the output shaft, and a power generation function for generating power by the power transmitted from the output shaft, A hybrid vehicle including a control unit that controls the internal combustion engine and the motor generator, the vehicle including a traveling state detection unit that detects a traveling state of the vehicle, the control unit stores the past traveling state, EV travel that travels with the power of the motor generator in a state where the operation of the internal combustion engine is stopped is limited based on the past travel state.

  As described above, according to the present invention, excessive EV traveling can be avoided, and fuel consumption can be improved.

FIG. 1 is a configuration diagram of a hybrid vehicle according to an embodiment of the present invention. FIG. 2 is a flowchart for explaining the operation of calculating the experience vehicle speed by the ECU of the hybrid vehicle according to the embodiment of the present invention. FIG. 3 is a flowchart for explaining the operation of calculating the number of EV experiences by the ECU of the hybrid vehicle according to one embodiment of the present invention. FIG. 4 is a flowchart for explaining the operation of limiting the EV traveling based on the conditions including the experience vehicle speed and the number of EV experiences by the ECU of the hybrid vehicle according to the embodiment of the present invention.

  A hybrid vehicle according to an embodiment of the present invention includes an internal combustion engine, an electric function that is coupled to an output shaft of the internal combustion engine, generates power to be transmitted to the output shaft, and a power generation function that generates power by the power transmitted from the output shaft And a control unit that controls the internal combustion engine and the motor generator. The hybrid vehicle includes a traveling state detection unit that detects a traveling state of the vehicle, and the control unit stores the past traveling state. Then, the EV traveling that travels by the power of the motor generator while the operation of the internal combustion engine is stopped is limited based on the past traveling state. Thereby, the hybrid vehicle which concerns on one embodiment of this invention can avoid excessive EV driving | running | working and can improve a fuel consumption.

  Hereinafter, a hybrid vehicle according to an embodiment of the present invention will be described with reference to the drawings. 1 to 4 are diagrams illustrating a hybrid vehicle according to an embodiment of the present invention.

  As shown in FIG. 1, the hybrid vehicle 10 includes an engine 20, a transmission 30, wheels 12, and an ECU (Electronic Control Unit) 50 that comprehensively controls the hybrid vehicle 10. The engine 20 in the present embodiment constitutes an internal combustion engine in the present invention. The ECU 50 in this embodiment constitutes a control unit in the present invention.

  The engine 20 is formed with a plurality of cylinders. In this embodiment, the engine 20 is configured to perform a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke for each cylinder. The engine 20 is provided with an intake pipe 22 for introducing air into a combustion chamber (not shown).

  A throttle valve 23 is provided in the intake pipe 22, and the throttle valve 23 adjusts the amount of air passing through the intake pipe 22 (intake amount). The throttle valve 23 is an electronically controlled throttle valve that is opened and closed by a motor (not shown). The throttle valve 23 is electrically connected to the ECU 50, and the throttle valve opening degree is controlled by the ECU 50.

  The engine 20 is provided with an injector 24 for injecting fuel into a combustion chamber via an intake port (not shown) and a spark plug 25 for igniting an air-fuel mixture in the combustion chamber for each cylinder. The injector 24 and the spark plug 25 are electrically connected to the ECU 50. The ECU 50 controls the fuel injection amount and fuel injection timing of the injector 24 and the ignition timing and discharge amount of the spark plug 25.

  The engine 20 is provided with a crank angle sensor 27. The crank angle sensor 27 detects the engine speed based on the rotational position of the crankshaft 20A and transmits a detection signal to the ECU 50.

  The transmission 30 shifts the rotation transmitted from the engine 20 and drives the wheels 12 via the drive shaft 11. The transmission 30 includes a torque converter, a speed change mechanism, and a differential mechanism (not shown).

  The torque converter performs torque amplification by converting the rotation transmitted from the engine 20 into torque by the action of the working fluid. The torque converter is provided with a lockup clutch (not shown). When the lockup clutch is released, power is transmitted between the engine 20 and the speed change mechanism via the working fluid. When the lockup clutch is engaged, power is directly transmitted between the engine 20 and the speed change mechanism via the lockup clutch.

  The transmission mechanism is composed of CVT (Continuously Variable Transmission), and automatically performs a variable transmission steplessly by a set of pulleys around which a metal belt is wound. The ECU 50 controls the change of the gear ratio in the transmission 30 and the engagement or disengagement of the lockup clutch.

  Note that the speed change mechanism may be an automatic transmission (so-called step AT) that performs a step change using a planetary gear mechanism. The differential mechanism is connected to the left and right drive shafts 11 and transmits the power shifted by the speed change mechanism to the left and right drive shafts 11 so as to be differentially rotatable.

The transmission 30 may be an AMT (Automated Manual Transmission). The AMT is an automatic transmission that automatically shifts by adding an actuator to a manual transmission having a parallel shaft gear mechanism. When the transmission 30 is an AMT, the transmission 30 is provided with a dry single-plate clutch instead of the torque converter.
The transmission 30 may be a DCT (Dual Clutch Transmission). DCT is a kind of stepped automatic transmission, has two gears, and each has a clutch.

  The hybrid vehicle 10 includes an accelerator opening sensor 13A. The accelerator opening sensor 13A detects an operation amount of the accelerator pedal 13 (hereinafter simply referred to as “accelerator opening”), and transmits a detection signal to the ECU 50. .

  The hybrid vehicle 10 includes a brake stroke sensor 14 </ b> A. The brake stroke sensor 14 </ b> A detects an operation amount of the brake pedal 14 (hereinafter simply referred to as “brake stroke”) and transmits a detection signal to the ECU 50.

  The hybrid vehicle 10 includes a vehicle speed sensor 12 </ b> A. The vehicle speed sensor 12 </ b> A detects a vehicle speed based on the rotational speed of the wheels 12 and transmits a detection signal to the ECU 50. The vehicle speed sensor 12A constitutes a traveling state detection unit in the present invention. The detection signal of the vehicle speed sensor 12A is used when the slip ratio of each wheel 12 with respect to the vehicle speed is calculated in the ECU 50 or another controller.

  The hybrid vehicle 10 includes a starter 26. The starter 26 includes a motor (not shown) and a pinion gear fixed to the rotation shaft of the motor. On the other hand, a disc-shaped drive plate is fixed to one end of the crankshaft 20A of the engine 20, and a ring gear is provided on the outer periphery of the drive plate. The starter 26 drives the motor in response to a command from the ECU 50, and meshes the pinion gear with the ring gear to rotate the ring gear, thereby starting the engine 20. As described above, the starter 26 starts the engine 20 through the gear mechanism including the pinion gear and the ring gear.

  The hybrid vehicle 10 includes an ISG (Integrated Starter Generator) 40. The ISG 40 is a rotating electrical machine that integrates a starter that starts the engine 20 and a generator that generates electric power. The ISG 40 has a function of a generator that generates power by power from the outside and a function of an electric motor that generates power when power is supplied.

  The ISG 40 is connected to the engine 20 via a winding transmission mechanism including a pulley 41, a crank pulley 21, and a belt 42, and transmits power to and from the engine 20. More specifically, the ISG 40 includes a rotating shaft 40A, and a pulley 41 is fixed to the rotating shaft 40A. A crank pulley 21 is fixed to the other end portion of the crankshaft 20 </ b> A of the engine 20. A belt 42 is stretched around the crank pulley 21 and the pulley 41. A sprocket and a chain can also be used as the winding transmission mechanism.

  The ISG 40 is driven as an electric motor to rotate the crankshaft 20A and start the engine 20. Here, the hybrid vehicle 10 of this embodiment includes an ISG 40 and a starter 26 as a starting device for the engine 20. The starter 26 is mainly used for cold start of the engine 20 based on the start operation of the driver, and the ISG 40 is mainly used for restart of the engine 20 from the idling stop.

  Although the ISG 40 can start the engine 20 cold, the hybrid vehicle 10 includes a starter 26 for reliable cold start of the engine 20. For example, the cold start of the engine 20 may be difficult with the power of the ISG 40 due to an increase in the viscosity of the lubricating oil in winter in a cold region, or the ISG 40 may fail. In consideration of such a case, the hybrid vehicle 10 includes both the ISG 40 and the starter 26 as starting devices.

  The power generated by the power running of the ISG 40 is transmitted to the wheels 12 via the crankshaft 20A of the engine 20, the transmission 30, and the drive shaft 11.

  The rotation of the wheel 12 is transmitted to the ISG 40 via the drive shaft 11, the transmission 30, and the crankshaft 20 </ b> A of the engine 20, and used for regeneration (power generation) in the ISG 40.

  As described above, the ISG 40 has an electric function for generating power to be transmitted to the crankshaft 20A of the engine 20 and a power generation function for generating power by the power transmitted from the crankshaft 20A. The crankshaft 20A constitutes an output shaft in the present invention. The ISG 40 constitutes a motor generator in the present invention.

  Therefore, the hybrid vehicle 10 can realize not only traveling by the power (engine torque) of the engine 20 (hereinafter also referred to as engine traveling) but also traveling that assists the engine 20 by the power (motor torque) of the ISG 40.

  Furthermore, the hybrid vehicle 10 can travel only with the power of the ISG 40 (hereinafter also referred to as EV traveling) in a state where fuel injection to the engine 20 is stopped. During EV travel, the engine 20 is rotated by the ISG 40.

  As described above, the hybrid vehicle 10 constitutes a parallel hybrid system that can travel using at least one of the power of the engine 20 and the power of the ISG 40.

  The hybrid vehicle 10 includes a lead battery 71 as a first power source and a Li battery 72 as a second power source. The lead battery 71 and the Li battery 72 are rechargeable secondary batteries. In the lead battery 71 and the Li battery 72, the number of cells and the like are set so as to generate an output voltage of about 12V.

  The lead battery 71 is a lead storage battery using lead as an electrode. The Li battery 72 is composed of a lithium ion secondary battery that discharges and charges when lithium ions move between the positive electrode and the negative electrode.

  Compared with the Li battery 72, the lead battery 71 has a characteristic capable of discharging a larger current for a short time.

  Compared to the lead battery 71, the Li battery 72 has a characteristic capable of repeating charging / discharging more times. Further, the Li battery 72 has a characteristic that it can be charged in a shorter time than the lead battery 71. Further, the Li battery 72 has a characteristic of higher output and higher energy density than the lead battery 71.

  The lead battery 71 is provided with a charge state detection unit 71A. The charge state detection unit 71A detects the inter-terminal voltage, the ambient temperature, and the input / output current of the lead battery 71, and outputs a detection signal to the ECU 50. The ECU 50 detects the state of charge based on the voltage between terminals of the lead battery 71, the ambient temperature, and the input / output current.

  The Li battery 72 is provided with a charge state detection unit 72A. The charge state detection unit 72A detects the inter-terminal voltage, the ambient temperature, and the input / output current of the Li battery 72, and outputs a detection signal to the ECU 50. The ECU 50 detects the state of charge based on the voltage between the terminals of the Li battery 72, the ambient temperature, and the input / output current. The state of charge (SOC) of the lead battery 71 and the Li battery 72 is managed by the ECU 50.

  The hybrid vehicle 10 includes a lead battery load 16 and a Li battery load 17 as electric loads.

  The lead battery load 16 is an electric load to which power is mainly supplied from the lead battery 71. The lead battery load 16 includes a stability control device that prevents the vehicle from skidding, an electric power steering control device (not shown) that electrically assists the operating force of the steering wheel, a headlight, a blower fan, and the like. The lead battery load 16 includes, for example, a wiper (not shown) and an electric cooling fan that blows cooling air to a radiator (not shown). The lead battery load 16 is an electric load that consumes more electric power than the Li battery load 17 or an electric load that is temporarily used.

  The Li battery load 17 is an electric load to which power is mainly supplied from the Li battery 72. The Li battery load 17 also includes lamps and meters of an instrument panel (not shown) and a car navigation system. The Li battery load 17 is an electric load that consumes less power than the lead battery load 16.

  The hybrid vehicle 10 includes a switching unit 60 that switches the power supply state among the lead battery 71, the Li battery 72, the lead battery load 16, the Li battery load 17, and the ISG 40. The switching unit 60 includes a mechanical relay, a semiconductor relay (also referred to as SSR: Solid State Relay), or the like, and is controlled by the ECU 50.

  Power cables 61, 62, 63, 64 are connected to the switching unit 60. The power cable 61 connects the switching unit 60, the lead battery 71, the lead battery load 16, and the starter 26 in parallel. The power cable 62 connects the switching unit 60 and the Li battery. The power cable 63 is connected to the switching unit 60 and the Li battery load 17. The power cable 64 connects the switching unit 60 and the ISG 40.

  Therefore, the lead battery load 16 and the starter 26 are constantly supplied with power from the lead battery 71. On the other hand, the power supply state is switched to the Li battery load 17 so that power is supplied from at least one of the Li battery 72 or the lead battery 71. Further, the power supply state is switched to the ISG 40 so that power is supplied from one of the Li battery 72 and the lead battery 71.

  The ECU 50 is a computer that includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, an input port, and an output port. It is composed of units.

  The ROM of this computer unit stores programs for causing the computer unit to function as the ECU 50, along with various constants, various maps, and the like. That is, when the CPU executes a program stored in the ROM using the RAM as a work area, these computer units function as the ECU 50 in this embodiment.

  Various sensors including the crank angle sensor 27, the accelerator opening sensor 13A, the brake stroke sensor 14A, the vehicle speed sensor 12A, and the charge state detection units 71A and 72A are connected to the input port of the ECU 50.

  Various control objects including various devices such as the throttle valve 23, the injector 24, the spark plug 25, the switching unit 60, the ISG 40, and the starter 26 are connected to the output port of the ECU 50. The ECU 50 controls various control objects based on information obtained from various sensors.

  The ECU 50 performs idling stop control that automatically stops and restarts the engine 20. In the idling stop control, the ECU 50 stops the engine 20 when the stop condition is satisfied, and restarts the engine 20 when the restart condition is satisfied during the stop. Moreover, ECU50 implements EV driving | running | working, when predetermined EV permission conditions are satisfied.

  In the present embodiment, in addition to this EV permission condition, EV travel is limited by setting additional EV permission conditions related to past travel conditions, and deterioration of fuel consumption due to excessive EV traveling is avoided. . Hereinafter, the operation of the ECU 50 regarding the additional EV permission condition will be described.

  In the present embodiment, the ECU 50 stores the past traveling situation and limits the EV traveling based on the past traveling situation.

  Specifically, the ECU 50 limits the EV traveling based on the experience vehicle speed that is the vehicle speed that has changed in the past. Moreover, ECU50 restrict | limits EV driving | running | working based on the frequency | count of EV experience which is the frequency | count which implemented EV driving | running in the past.

  When starting from a state where the operation of the engine 20 is stopped due to idling stop, the ECU 50 permits EV traveling regardless of past traveling conditions.

  The operation of calculating the experience vehicle speed by the ECU 50 will be described with reference to the flowchart shown in FIG.

  In FIG. 2, in step S1, the ECU 50 determines whether the engine is stopped due to idling stop or the vehicle speed is 0 km / h.

  If the engine is stopped in step S1 or if the vehicle speed is 0 km / h, the ECU 50 sets the experienced vehicle speed to 0 km / h in step S5 and ends the current operation.

  If the engine is not stopped in step S1 and the vehicle speed is not 0 km / h, the ECU 50 determines in step S2 whether or not the current vehicle speed (shown as current vehicle speed in the figure) is equal to or higher than the current experience vehicle speed. judge.

  If the current vehicle speed is less than the current experienced vehicle speed in step S2, the ECU 50 maintains the experienced vehicle speed at the current experienced vehicle speed (that is, the previous value) in step S3, and ends the current operation.

  If the current vehicle speed is greater than or equal to the current experienced vehicle speed in step S2, the ECU 50 updates the experienced vehicle speed to the current vehicle speed in step S4 and ends the current operation.

  Thus, the ECU 50 updates the experienced vehicle speed to the current vehicle speed when the current vehicle speed is equal to or higher than the current experienced vehicle speed (previous value of the experienced vehicle speed), and otherwise sets the experienced vehicle speed to the previous value. Hold on.

  The operation of calculating the number of EV experiences by the ECU 50 will be described with reference to the flowchart shown in FIG.

  In FIG. 3, in step S11, the ECU 50 determines whether the engine is stopped due to idling stop or whether the vehicle speed is equal to or higher than a predetermined threshold (40 km / h as an example).

  If the engine is not stopped in step S11 and the vehicle speed is less than the threshold value, the ECU 50 determines in step S12 whether or not EV traveling (simply indicated as EV in the figure) has ended.

  When the EV travel ends in step S12, the ECU 50 counts up the number of EV experiences.

  If the EV travel has not ended in step S12, the ECU 50 holds the EV experience count at the previous value in step S13.

  If the engine is stopped in step S11 or the vehicle speed is equal to or higher than the threshold value, the ECU 50 resets the EV experience count to 0 in step S15 and ends the current operation.

  Thus, the ECU 50 counts up the number of EV experiences at the end of EV travel. However, the ECU 50 resets the number of EV experiences to 0 when the engine 20 is stopped due to idling stop or when the vehicle speed becomes equal to or higher than a predetermined threshold (40 km / h in FIG. 3).

  The EV traveling restriction operation by the ECU 50 will be described with reference to the flowchart shown in FIG.

  4, in step S31, the ECU 50 determines whether the experience vehicle speed calculated in FIG. 2 is equal to or higher than a predetermined threshold value (40 km / h as an example) or the engine is stopped due to idling stop. The ECU 50 determines YES in step S31 when any of these conditions is satisfied. The ECU 50 repeats step S31 until it is determined YES.

  If the determination in step S31 is YES, the ECU 50 determines whether or not the number of EV experiences calculated in FIG. 3 is equal to or less than a predetermined threshold (one time as an example). The ECU 50 determines YES in step S32 when the condition of the number of EV experiences is satisfied. The ECU 50 repeats step S32 until it is determined YES.

  If the determination in step S32 is YES, the ECU 50 repeats the determination in step S33 as to whether or not the other EV permission conditions are satisfied. , Simply referred to as EV).

  Here, the vehicle state determined as YES in each of step S31 and step S32 corresponds to a state where electric power is generated by traveling and this electric power is not consumed by EV traveling. In other words, the ECU 50 permits the EV traveling immediately after accumulating electric power by regeneration and when other EV permission conditions are satisfied in step S33.

  Further, as described above, when the ECU 50 starts from a state where the operation of the engine 20 is stopped due to idling stop, the ECU 50 permits EV traveling regardless of past traveling conditions.

  Therefore, the ECU 50 limits the EV travel so that the EV travel is permitted immediately after accumulating electric power during regeneration or only at the time of starting. By limiting EV travel in this way, power shortage and increase in power generation due to excessive EV travel can be suppressed, and fuel consumption can be improved.

  As described above, the hybrid vehicle 10 according to the present embodiment includes the vehicle speed sensor 12A as a traveling state detection unit that detects the traveling state of the vehicle.

  Then, the ECU 50 stores the detected past traveling situation, and restricts EV traveling that is driven by the power of the ISG 40 in a state where the operation of the engine 20 is stopped based on the past traveling situation.

  Thereby, it can be determined based on the past driving situation that the electric power required for carrying out EV driving is not stored in the lead battery 71 or the Li battery 72, and EV driving can be restricted.

  As a result, excessive EV traveling can be avoided and fuel consumption can be improved.

  Further, in the hybrid vehicle 10 according to the present embodiment, the vehicle speed sensor 12A detects the vehicle speed as the traveling state.

  And ECU50 restrict | limits EV driving | running | working based on the experience vehicle speed which is the vehicle speed which changed in the past.

  Thereby, it can be determined based on the experience vehicle speed whether the electric power required for implementation of EV driving | running is accumulate | stored in the lead battery 71 or the Li battery 72, and EV driving | running | working can be restrict | limited.

  As a result, excessive EV traveling can be avoided and fuel consumption can be improved.

  Further, in the hybrid vehicle 10 according to the present embodiment, the ECU 50 limits the EV travel based on the number of EV experiences that is the number of times EV travel has been performed in the past.

  Thereby, it can be determined based on the number of EV experiences whether or not the electric power required for carrying out the EV traveling is accumulated in the lead battery 71 or the Li battery 72, and the EV traveling can be restricted.

  As a result, excessive EV traveling can be avoided and fuel consumption can be improved.

  Further, in the hybrid vehicle 10 according to the present embodiment, the ECU 50 permits EV traveling regardless of past traveling conditions when the engine 20 starts from a state where the operation of the engine 20 is stopped due to idling stop.

  As a result, the EV travel can be realized by the driver when starting from the idling stop, and the drive feeling can be improved.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

10 Hybrid vehicle 12A Vehicle speed sensor (traveling condition detection unit)
20 engine (internal combustion engine)
40 ISG (Motor Generator)
50 ECU (control unit)

Claims (4)

An internal combustion engine;
A motor generator coupled to the output shaft of the internal combustion engine and having an electric function for generating power to be transmitted to the output shaft and a power generation function for generating power by the power transmitted from the output shaft;
A control unit that controls the internal combustion engine and the motor generator,
A traveling state detection unit that detects the traveling state of the vehicle,
The controller is
Memorize the past driving situation,
A hybrid vehicle that restricts EV traveling that is driven by the power of the motor generator in a state where the operation of the internal combustion engine is stopped, based on the past traveling state. The traveling state detection unit detects a vehicle speed as the traveling state,
The controller is
The hybrid vehicle according to claim 1, wherein the EV traveling is limited based on an experienced vehicle speed that is a vehicle speed that has changed in the past. The controller is
The hybrid vehicle according to claim 1, wherein the EV traveling is limited based on the number of EV experiences that is the number of times the EV traveling has been performed in the past. The controller is
When starting from a state where the operation of the internal combustion engine is stopped by idling stop,
The hybrid vehicle according to any one of claims 1 to 3, wherein the EV traveling is permitted regardless of the past traveling state.