JP2014189081A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To, when a power larger than a power which an engine can output through number-of-rotations limitation is requested, allow a vehicle to travel by suppressing degradation of fuel economy and outputting the requested power.SOLUTION: When a number-of-rotations limit Nelim is imposed on an engine, if a shortage power ΔP obtained by subtracting an engine upper limit power Pelim from a traveling power Pdrv is larger than an output limit Wout of a battery, an opening/closing timing of an intake valve is advanced by a variable valve timing mechanism, and an engine is run at a running point associated with the number-of-rotations limit Nelim and a torque obtained by dividing a difference, which is obtained by subtracting the battery 50 output limit Wout from the traveling power Pdrv, by the number-of-rotations limit Nelim (S190). Control is implemented so that a vehicle can travel by outputting a power equivalent to the output limit Wout from the battery, and outputting the traveling power Pdrv to a driving axle (S200 to S220).

Description

  The present invention relates to a hybrid vehicle, and more particularly, to an engine having a variable valve timing mechanism that changes the opening / closing timing of an intake valve, a first motor capable of generating power, an output shaft of the engine, a rotating shaft of the first motor, and an axle. A planetary gear mechanism in which three rotating elements are connected to a connected drive shaft, a second motor that inputs and outputs driving power, a battery that can exchange power with the first motor and the second motor, Relates to a hybrid vehicle comprising

  Conventionally, in this type of hybrid vehicle, the engine is normally operated at the operating point with the highest operating efficiency with respect to the required power. One that increases the torque so that it can be output and operates the engine has been proposed (see, for example, Patent Document 1). In this hybrid vehicle, the torque is increased by controlling the variable valve timing mechanism according to a map based on the engine speed and torque and changing the opening / closing timing of the intake valve. And by such control, the electric power supply from a battery is suppressed and driving efficiency is improved even when required power is large.

  In addition, when the engine required power, which is the sum of the required travel power input from the accelerator pedal and the required battery charge power, exceeds the best fuel efficiency range of the engine, there is proposed one that limits the required charge power of the battery. (For example, refer to Patent Document 2). In this hybrid vehicle, such control suppresses a reduction in fuel consumption.

Japanese Patent Laid-Open No. 11-117782 JP 2010-184572 A

  However, in the above-described hybrid vehicle, if the engine torque is increased immediately when the engine cannot be driven at the driving point due to the rotational speed limitation due to the required power, the fuel consumption of the vehicle is deteriorated. In the latter hybrid vehicle, when the required travel power input from the accelerator pedal exceeds the engine fuel efficiency best range, even if the required charge power of the battery is limited, it cannot be coped with.

  The hybrid vehicle of the present invention has a main purpose of outputting the requested power while suppressing a decrease in fuel consumption when a power greater than the power that can be output by the engine due to the rotational speed limitation is requested. And

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
Three rotating elements are connected to an engine having a torque increasing mechanism for increasing torque, a first motor capable of generating electricity, an output shaft of the engine, a rotating shaft of the first motor, and a driving shaft connected to an axle. A hybrid vehicle comprising: a planetary gear mechanism; a second motor that inputs and outputs driving power; and a battery that can exchange power with the first motor and the second motor,
On the fuel efficiency priority operation line in which fuel efficiency is given priority in order to output from the engine the traveling power required for traveling of the vehicle while the rotational speed limit for driving the engine at a predetermined rotational speed or less is imposed. When the engine is operated at the time when the engine speed becomes larger than the predetermined engine speed, the engine is operated at an upper limit operation point corresponding to the predetermined engine speed on the fuel consumption priority operation line. When the insufficient power obtained by subtracting the power output from the engine from the driving power when driving is greater than the allowable maximum power that can be output from the battery, the torque increasing mechanism from the engine operating at the predetermined speed The power obtained by subtracting the allowable maximum power from the traveling power with an increase in torque due to Both control means for controlling said engine and said first motor and said second motor so as to run through the traveling power and outputting the maximum allowable power from said battery,
It is characterized by providing.

  In the hybrid vehicle of the present invention, (1) the engine speed is restricted to be operated at a predetermined speed or less, and (2) the power (Pdrv) for traveling required for traveling of the vehicle is engine. When the engine is operated on a fuel efficiency priority operation line that gives priority to fuel efficiency in order to output from the engine, the engine speed becomes a speed greater than the predetermined speed, and (3) the engine is operated in the fuel efficiency priority operation line. Underpower (ΔP = Pdrv-Pelim) obtained by subtracting the power output from the engine (Pelim) from the driving power (Pdrv) when operating at the upper limit operating point corresponding to the above predetermined rotational speed can be output from the battery When the above three conditions are satisfied, the operation is performed at a predetermined rotational speed. The engine outputs a power obtained by subtracting the allowable maximum power (Pbmax) from the traveling power (Pdrv) with an increase in torque by the torque increasing mechanism and outputs the allowable maximum power (Pbmax) from the battery. The engine, the first motor, and the second motor are controlled to run with power (Pdrv). As a result, in order to travel with the power for traveling (Pdrv), the acceleration of battery deterioration is suppressed and the increase in torque by the torque increasing mechanism is minimized, while the power for traveling (Pdrv) is suppressed while suppressing the decrease in fuel consumption. It can drive by.

  Here, as the torque increasing mechanism, a variable valve timing mechanism for changing the opening / closing timing of the intake valve, a supercharger such as a turbocharger or a supercharger, or the like can be used.

  In the hybrid vehicle of the present invention, (1) the engine speed limit is imposed on the engine at a predetermined speed or less, and (2) the driving power (Pdrv) required for driving the vehicle is from the engine. When the engine is operated on a fuel efficiency priority operation line that gives priority to fuel efficiency for output, the engine speed is when the engine speed is greater than the predetermined speed, and (3) the engine Is the insufficient power (ΔP = Pdrv−Pelim) obtained by subtracting the power (Pelim) output from the engine from the driving power (Pdrv) when driving at the upper limit operating point corresponding to the predetermined rotational speed on the fuel consumption priority operation line Is less than the maximum allowable power (Pbmax) that can be output from the battery, the engine is operated at the upper limit operating point and the battery is It may be one that controls the engine and the first motor and the second motor so as to run due to a lack of Li power traveling power and output (ΔP) (Pdrv). By so doing, it is not necessary to increase the torque by the torque increasing mechanism, so that it is possible to suppress a reduction in fuel consumption and to travel with the traveling power (Pdrv).

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. 3 is a flowchart showing an example of a drive control routine in an engine operation mode executed by an HVECU 70. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows a mode that the target rotational speed Ne * and the target torque Te * are set when an example of the optimal fuel consumption line and the maximum torque line and the insufficient power ΔP is a negative value. FIG. 3 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of a power distribution and integration mechanism 30 when traveling with power output from an engine 22; It is explanatory drawing which shows a mode that the target rotational speed Ne * and the target torque Te * are set when an example of the optimal fuel consumption line and the maximum torque line and the insufficient power ΔP is a positive value and is equal to or less than the output limit Wout. It is explanatory drawing which shows a mode that the target rotational speed Ne * and the target torque Te * are set when an example of the optimal fuel efficiency line and the maximum torque line and the insufficient power ΔP is a positive value and larger than the output limit Wout. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment inputs signals from an engine 22 that uses gasoline or light oil as fuel and various sensors that detect the operating state of the engine 22, and also performs fuel injection control and ignition control of the engine 22. , A carrier is connected to an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that performs intake air amount adjustment control, and a crankshaft 26 that serves as an output shaft of the engine 22, and a differential gear 62 is connected to the drive wheels 63a and 63b. A planetary gear 30 in which a ring gear is connected to a drive shaft 32 connected via a motor, a motor MG1 configured as, for example, a synchronous generator motor and a rotor connected to a sun gear of the planetary gear 30, and a motor as a synchronous generator motor, for example. Motor MG having a rotor connected to drive shaft 32 And inverters 41 and 42 for driving the motors MG1 and MG2, and a motor electronic control unit (hereinafter referred to as a motor ECU) for driving and controlling the motors MG1 and MG2 by switching control of switching elements (not shown) of the inverters 41 and 42. 40), a battery 50 configured as, for example, a lithium ion secondary battery and exchanging electric power with the motors MG1 and MG2 via inverters 41 and 42, a voltage between terminals of the battery 50, a charge / discharge current Ib, a battery temperature Tb The shift position SP and the depression amount of the accelerator pedal 83 are detected from a battery electronic control unit (hereinafter referred to as a battery ECU) 52 that manages the battery 50 by using a shift position sensor 82 that detects the position of the shift lever 81. Accelerator pedal The accelerator opening Acc from the position sensor 84, the brake position from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88 and the like are inputted, and the engine ECU 24, the motor ECU 40, the battery ECU 52 and the like. And a hybrid electronic control unit 70 that controls the entire vehicle by communication.

  The engine 22 is configured as an engine capable of outputting power using a hydrocarbon fuel such as gasoline or light oil, for example, and as shown in FIG. 2, the air purified by an air cleaner 122 is sucked through a throttle valve 124. At the same time, gasoline is injected from the fuel injection valve 126 to mix the sucked air and gasoline, the mixture is sucked into the combustion chamber through the intake valve 128, and is explosively burned by an electric spark from the spark plug 130. The reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 26. The exhaust from the engine 22 is discharged to the outside air through a purification device 134 having a purification catalyst (three-way catalyst) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The exhaust gas is supplied to the intake side via an exhaust gas recirculation device 160 (hereinafter referred to as an “EGR (Exhaust Gas Recirculation) system”) 160 that recirculates the exhaust gas to the intake air. The EGR system 160 includes an EGR pipe 162 that is connected to the rear stage of the purification device 134 and supplies exhaust gas to a surge tank on the intake side, and an EGR valve 164 that is disposed in the EGR pipe 162 and is driven by a stepping motor 163. Then, by adjusting the opening degree of the EGR valve 164, the recirculation amount of the exhaust gas as the non-combustion gas is adjusted to recirculate to the intake side. In this way, the engine 22 can suck a mixture of air, exhaust, and gasoline into the combustion chamber. Hereinafter, the recirculation of the exhaust of the engine 22 to the intake side is referred to as EGR, and the amount of the exhaust gas recirculated to the intake side is referred to as an EGR amount Ve.

  The engine ECU 24 is configured as a microprocessor centered on the CPU 24a, and includes a ROM 24b that stores a processing program, a RAM 24c that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 24a. . The engine ECU 24 receives signals from various sensors that detect the state of the engine 22, for example, a crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 26, and a water temperature that detects the temperature of cooling water in the engine 22. The cooling water temperature Tw from the sensor 142, the intake valve 128 that performs intake and exhaust to the combustion chamber, the cam position from the cam position sensor 144 that detects the rotational position of the camshaft that opens and closes the exhaust valve, and the throttle that detects the position of the throttle valve 124 The throttle opening TH from the valve position sensor 146, the intake air amount Qa from the air flow meter 148 attached to the intake pipe, the intake air temperature Ta from the temperature sensor 149 also attached to the intake pipe, and the pressure in the intake pipe are detected. Intake pressure sensor 1 8, the catalyst temperature Tc from the temperature sensor 134 a attached to the purifier 134, the air-fuel ratio AF from the air-fuel ratio sensor 135 a, the oxygen signal O2 from the oxygen sensor 135 b, and the cylinder block for knocking. The knock signal Ks from the knock sensor 159 that detects vibrations generated by the occurrence, the EGR valve opening degree EV from the EGR valve opening degree sensor 165 that detects the opening degree of the EGR valve 164, and the like are input via the input port. Yes. The engine ECU 24 also integrates various control signals for driving the engine 22, such as a drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, and an igniter. The control signal to the ignition coil 138, the control signal to the variable valve timing mechanism 150 that can change the opening / closing timing of the intake valve 128, the drive signal to the stepping motor 163 that adjusts the opening degree of the EGR valve 164, and the like are output. It is output through the port. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and outputs data related to the operation state of the engine 22 as necessary. The engine ECU 24 calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on the crank position from the crank position sensor 140, and the intake air amount Qa from the air flow meter 148 and the rotational speed of the engine 22. The volumetric efficiency (ratio of the volume of air actually sucked in one cycle to the stroke volume per cycle of the engine 22) KL is calculated based on Ne, or the intake air amount Qa from the air flow meter 148 and the EGR valve Based on the EGR valve opening degree EV from the opening degree sensor 165 and the rotational speed Ne of the engine 22, an EGR rate Re as a ratio of the EGR amount Ve to the sum of the EGR amount Ve and the intake air amount Qa of the engine 22 is calculated. Or based on the magnitude and waveform of the knock signal Ks from the knock sensor 159. It is or calculating the knock intensity Kr indicating the occurrence level of knocking.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, such as rotational positions θm1 and θm2 from a rotational position detection sensor for detecting the rotational position of the rotor of the motors MG1 and MG2, and a current sensor (not shown). The detected phase current applied to the motors MG1 and MG2 is input through the input port, and the switching control signal to the inverters 41 and 42 is output from the motor ECU 40 through the output port. . The motor ECU 40 is in communication with the HVECU 70, controls the driving of the motors MG1 and MG2 by a control signal from the HVECU 70, and outputs data related to the operating state of the motors MG1 and MG2 to the HVECU 70 as necessary. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotational position detection sensor.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The battery ECU 52 receives signals necessary for managing the battery 50, for example, an inter-terminal voltage Vb from a voltage sensor (not shown) installed between the terminals of the battery 50 and a power line connected to the output terminal of the battery 50. The charging / discharging current Ib from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor (not shown) attached to the battery 50, and the like are input. Send to. Further, in order to manage the battery 50, the battery ECU 52 is a power storage that is a ratio of the capacity of the electric power that can be discharged from the battery 50 at that time based on the integrated value of the charge / discharge current Ib detected by the current sensor. The ratio SOC is calculated, and the input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limiting limit are set based on the storage ratio SOC of the battery 50. It can be set by setting a correction coefficient and multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU. In addition to the CPU, a ROM that stores processing programs, a RAM that temporarily stores data, and a nonvolatile flash that holds the stored data Equipped with memory, input / output port and communication port. The HVECU 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator opening degree from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. Acc, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

  The hybrid vehicle 20 of the embodiment configured in this way calculates the required torque to be output to the drive shaft 32 based on the accelerator opening Acc and the vehicle speed V corresponding to the amount of depression of the accelerator pedal 83 by the driver. The operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the torque is output to the drive shaft 32. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motor MG1. And the motor MG2 convert the torque and output to the drive shaft 32. The torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 and the power suitable for the sum of the required power and the power required for charging and discharging the battery 50 are obtained. The operation of the engine 22 is controlled so as to be output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the battery 50 is converted by the planetary gear 30, the motor MG1, and the motor MG2. Accordingly, the required power is output to the drive shaft 32. Charge-discharge drive mode for driving and controlling the motor MG1 and the motor MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 32. Both the torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1, MG2 are controlled so that the required power is output to the drive shaft 32 with the operation of the engine 22. Since there is no difference in the control, both are hereinafter referred to as the engine operation mode.

  In the engine operation mode, the hybrid electronic control unit 70 sets the required torque Tr * to be output to the drive shaft 32 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. Then, the set required torque Tr * is multiplied by the rotational speed Nr of the drive shaft 32 (for example, the rotational speed obtained by multiplying the rotational speed Nm2 of the motor MG2 by the conversion factor or the rotational speed obtained by multiplying the vehicle speed V by the conversion factor). And calculating the driving power Pr * required for driving and the charging / discharging required power Pb * of the battery 50 obtained from the calculated driving power Pr * based on the storage ratio SOC of the battery 50 (when discharging from the battery 50) Is set to the required power Pe * as the power to be output from the engine 22 by subtracting The target rotational speed Ne * and the target torque Te * of the engine 22 using an operation line (for example, a fuel efficiency optimum operation line) as a relationship between the rotational speed Ne of the engine 22 and the torque Te that can be output from the engine 22 efficiently And the rotational speed Ne of the engine 22 is within the range of the input / output limits Win and Wout set by the storage ratio SOC of the battery 50 and the temperature of the battery 50 as the maximum power that may charge and discharge the battery 50. A torque command Tm1 * as a torque to be output from the motor MG1 is set by the rotational speed feedback control for achieving the rotational speed Ne *, and when the motor MG1 is driven by the torque command Tm1 *, the planetary gear 30 is used. Torque of the motor MG2 by subtracting the torque acting on the drive shaft 32 from the required torque Tr * Set the decree Tm2 *, the target rotation speed Ne * and the target torque Te * capital transmitted to the engine ECU 24, the torque command Tm1 *, the Tm2 * is sent to the motor ECU 40. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * sets a target EGR rate Re * as a target value for the EGR rate Re based on the target rotational speed Ne * and the target torque Te *. The engine 22 is controlled so that the engine 22 is operated by the target rotational speed Ne * and the target torque Te * (specifically, the intake air amount control for controlling the opening degree of the throttle valve 124 and the fuel injection valve 126). Fuel injection control for controlling the fuel injection amount, ignition control for controlling the ignition timing of the spark plug 130, intake valve timing variable control for controlling the opening / closing timing of the intake valve 128, etc.) and the EGR rate Re is set to the target EGR rate Re EGR control for controlling the opening degree of the EGR valve 164 of the EGR system 160 is performed so as to satisfy *. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. In the engine operation mode, the operation of the engine 22 is stopped when the required power Pe * is less than a preset threshold value Pstop because it is better to stop the operation of the engine 22 in order to operate the engine 22 efficiently. Transition to motor operation mode.

  In the motor operation mode, the hybrid electronic control unit 70 sets the torque command Tm1 * of the motor MG1 to a value of 0 and outputs the required torque Tr * to the drive shaft 32 within the range of the input / output limits Win and Wout of the battery 50. Then, torque command Tm2 * of motor MG2 is set and transmitted to motor ECU 40. Then, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. In the motor operation mode, the engine 22 is started and the engine is operated when the above-mentioned required power Pe * reaches or exceeds a preset threshold value Pstart that it is better to start the engine 22 in order to operate the engine 22 efficiently. Enter mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when the engine 22 is subjected to the rotational speed limit Nelim will be described. FIG. 3 is a flowchart showing an example of a drive control routine in the engine operation mode executed by the HVECU 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, first, the HVECU 70 first determines the accelerator opening degree Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speeds Nm1, Nm2 of the motors MG1, MG2, and the rotational speed of the engine 22. Processing for inputting data necessary for control such as restriction Nelim, input / output restriction Win, Wout of the battery 50 is executed (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensor. To do. Further, the input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 and the storage ratio SOC of the battery 50 and are input from the battery ECU 52 by communication. Further, the engine speed limit Nelim of the engine 22 is set by a rotation speed limit setting routine (not shown). The engine speed limit Nelim of the engine 22 is set due to various factors, and a main factor may be based on the speed limit of the planetary gear 30. In the planetary gear 30, the following equation (1) is satisfied among the gear ratio ρ (the number of teeth of the sun gear / the number of teeth of the ring gear), the rotational speed Ns of the sun gear, the rotational speed Nc of the planetary carrier, and the rotational speed Nr of the ring gear. ) Is established. The rotation speed Nr of the ring gear is a parameter equivalent to the vehicle speed V, and the rotation speed Nc of the planetary carrier is a parameter equivalent to the rotation speed Ne of the engine 22. Since there is a mechanical limit value for the rotation speed Ns of the sun gear, the maximum rotation speed Nc of the planetary carrier changes according to the rotation speed Nr of the ring gear under this limit value, and the rotation speed Nr is 0. Sometimes it is the smallest and increases as the rotational speed Nr increases. For these reasons, the rotational speed limit Nelim of the engine 22 varies with the vehicle speed V.

  Ns = Nc + (Nc−Nr) / ρ (1)

  When the data is input in this way, the required torque Tr * to be output to the drive shaft 32 connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the input accelerator opening Acc and the vehicle speed V and the required travel. A traveling power Pdrv to be set is set (step S110). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. FIG. 4 shows an example of the required torque setting map. The travel power Pdrv can be calculated by multiplying the set required torque Tr * by the rotational speed Nr of the drive shaft 32. The rotational speed Nr of the drive shaft 32 is obtained by multiplying the vehicle speed V by the conversion coefficient kv (Nr = kv · V), or by multiplying the rotational speed Nm2 of the motor MG2 by the conversion coefficient km (Nr = km · Nm2). ).

  Subsequently, using the engine speed limit Nelim and the optimum fuel efficiency line, the power output from the engine 22 when the engine 22 is operated at the engine speed limit Nelim on the optimum fuel efficiency line is calculated as the engine upper limit power Pelim ( Step S120). FIG. 5 is an explanatory diagram showing an example of the optimum fuel consumption line and the maximum torque line and how the target rotational speed Ne * and the target torque Te * are set when the insufficient power ΔP is a negative value. In the figure, the optimal dynamic fuel consumption line is a continuous curve showing the operating point at which the fuel consumption (energy efficiency) is the best with respect to the rotational speed of the engine 22 including the operation of the variable valve timing mechanism 150 and the EGR system 160. The maximum torque line is a continuous curve showing the operating point that outputs the maximum torque with respect to the rotational speed of the engine 22 including the operation of the variable valve timing mechanism 150 and the EGR system 160. The engine upper limit power Pelim is determined when the engine 22 is operated at the operating point of the intersection of the rotational speed limit Nelim and the optimum fuel consumption line, that is, the operating point consisting of the rotational speed limit Nelim and the corresponding torque Telim. This means the power output from. The manner in which the target rotational speed Ne * and the target torque Te * are set when the insufficient power ΔP is a negative value will be described later.

  Next, the engine upper limit power Pelim is subtracted from the driving power Pdrv to calculate the insufficient power ΔP (step S130), and whether or not the insufficient power ΔP is greater than the value 0, that is, the traveling power Pdrv is greater than the engine upper limit power Pelim. It is determined whether it is larger (step S140). When the insufficient power ΔP is 0 or less, that is, when the travel power Pdrv is less than or equal to the engine upper limit power Pelim, the travel power Pdrv is used even when the engine speed limit Nelim is imposed, and the engine 22 is operated on the optimum fuel consumption line. It is determined that the engine 22 can be operated and output from the engine 22, and the engine 22 is required to have a smaller one of the engine power upper limit Pelim obtained by subtracting the charge / discharge required power Pb * from the traveling power Pdrv It is set as the power Pe * (step S160), and the target rotational speed Ne * and the target torque Te * are set as operating points at which the engine 22 should be operated using the set required power Pe * and the optimum fuel consumption line ( Step S170). The setting of the target rotational speed Ne * and the target torque Te * can be obtained as the rotational speed and torque at the operating point at the intersection of the curve with the constant required power Pe * and the optimum fuel consumption line. Considering the case where the charge / discharge required power Pb * is 0, the required power Pe * matches the travel power Pdrv (Pe * = Pdrv), so the target rotational speed Ne * and the target torque Te * are shown in FIG. Then, the traveling power Pdrv can be obtained as an intersection of a constant curve and the optimum fuel consumption line.

  When the target rotational speed Ne * and the target torque Te * are thus set, the following equation (2) is obtained using the target rotational speed Ne * of the engine 22, the rotational speed Nm2 of the motor MG2, and the gear ratio ρ of the power distribution and integration mechanism 30. To calculate the target rotational speed Nm1 * of the motor MG1 and set the torque command Tm1 * of the motor MG1 by the equation (3) based on the calculated target rotational speed Nm1 * and the input rotational speed Nm1 of the motor MG1 (step) S200). Here, Expression (2) is a dynamic relational expression for the rotating elements (sun gear, ring gear, planetary carrier) of the planetary gear 30. FIG. 6 is a collinear diagram showing the dynamic relationship between the rotational speed and torque of the rotating elements (sun gear, ring gear, planetary carrier) of the planetary gear 30 when traveling with the engine 22 outputting power. Show. In the figure, the left S-axis indicates the rotation speed Ns of the sun gear, which is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed Nc of the planetary carrier, which is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the drive shaft 32 which is the rotational speed Nm2 is shown. Equation (2) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate the torque that the torque Tm1 output from the motor MG1 acts on the drive shaft 32 and the torque that the torque Tm2 output from the motor MG2 acts on the drive shaft 32. Expression (3) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (3), “k1” in the second term on the right side is a gain of the proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / ρ (2)
Tm1 * = ρ ・ Te * / (1 + ρ) + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (3)

  Then, the torque command Tm2 * of the motor MG2 is set by adding the torque command Tm1 * set to the required torque Tr * divided by the gear ratio ρ of the planetary gear 30 according to the following equation (4) (step S210). . Equation (4) can be easily derived from the alignment chart of FIG.

  Tm2 * = Tr * + Tm1 * / ρ (4)

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S220), and the drive control routine is terminated. When the engine ECU 24 receives the target rotational speed Ne * and the target torque Te * as operating points on the optimum fuel consumption line, the engine 22 is operated at the operating point indicated by the target rotational speed Ne * and the target torque Te *. Thus, control such as intake air amount control, fuel injection control, ignition control, valve timing control, and EGR control in the engine 22 is performed. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. To do. With such control, the engine 22 can be operated at an operation point on the optimum fuel consumption line, and the travel power Pdrv can be output to the drive shaft 32 to travel.

  When it is determined in step S140 that the insufficient power ΔP is greater than 0, that is, when it is determined that the traveling power Pdrv is greater than the engine upper limit power Pelim, is the insufficient power ΔP less than or equal to the output limit Wout of the battery 50? It is determined whether or not (step S150). When the insufficient power ΔP is equal to or less than the output limit Wout of the battery 50, in order to operate the engine 22 at the speed limit Nelim on the optimum fuel consumption line, the speed limit Nelim is set to the target speed Ne * and the target torque Te *. Is set to a torque upper limit Telim corresponding to the rotational speed limit Nelim on the optimal fuel consumption line (step S180), and the torque command Tm1 * and motor MG2 of the motor MG1 are set using the set target rotational speed Ne * and target torque Te *. Torque designation Tm2 * (steps S200 and S210), the target engine speed Ne * and target torque Te * of the engine 22 are set to the engine ECU 24, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set to the motor. Each of them is transmitted to the ECU 40 (step S220) and the drive control routine To end the routine.

  FIG. 7 is an explanatory diagram showing an example of the optimum fuel consumption line and the maximum torque line and how the target rotational speed Ne * and the target torque Te * are set when the insufficient power ΔP is a positive value and is equal to or less than the output limit Wout. . In the figure, the entire hatched portion of the torque Telim or more including the hatched portion of “ΔP” is the output limit Wout of the battery 50. The rotational speed Ne1 at the operation point at the intersection of the curve with the constant travel power Pdrv and the optimum fuel consumption line is larger than the rotational speed limit Nelim, and the torque Te1 corresponding to the rotational speed limit Nelim with the constant travel power Pdrv is It becomes larger than the torque Telim. The traveling power Pdrv is the product of the rotational speed limit Nelim and the torque Te1 (in FIG. 7, the portion surrounded by the four straight lines x-axis, y-axis, x = Nelim, y = Te1). When operating at the operation point of Nelim and torque Telim, there is a shortage of insufficient power ΔP (the portion hatched as “ΔP” in FIG. 7) obtained by multiplying the torque obtained by subtracting the torque Telim from the torque Te1 by the rotation speed limit Nelim. It will be. Since the insufficient power ΔP is less than or equal to the output limit Wout of the battery 50, if the insufficient power ΔP is output from the battery 50, the vehicle travels by outputting the required torque Tr * to the drive shaft 32. The above-described processing of steps S180 and S200 to S220 is this control. With such control, the engine 22 can be operated at an operation point on the optimum fuel consumption line, and the travel power Pdrv can be output to the drive shaft 32 to travel.

  When it is determined in step S150 that the insufficient power ΔP is larger than the output limit Wout of the battery 50, it is determined that the engine 22 cannot be operated at the operating point on the optimal fuel consumption line under the condition that the rotational speed limit Nelim is imposed. The target rotational speed Ne * is set with the rotational speed limit Nelim, and the target torque Te * is set by the value obtained by subtracting the battery 50 output limit Wout from the traveling power Pdrv and dividing by the rotational speed limit Nelim (step). S190), using the set target rotational speed Ne * and the target torque Te *, a torque command Tm1 * of the motor MG1 and a torque designation Tm2 * of the motor MG2 are set (steps S200 and S210), and the target rotation of the engine 22 is set. For the number Ne * and the target torque Te *, the engine ECU 24 MG1, MG2 of the torque commands Tm1 *, Tm2 * and sends each motor ECU40 for (step S220), and terminates the drive control routine.

  FIG. 8 is an explanatory diagram showing an example of the optimal fuel consumption line and the maximum torque line and how the target rotational speed Ne * and the target torque Te * are set when the insufficient power ΔP is a positive value and larger than the output limit Wout. . In the figure, the entire hatched portion of the torque Telim or more including the hatched portion of “Wout” is the insufficient power ΔP. As in the case where the insufficient power ΔP is a positive value and is less than or equal to the output limit Wout, the rotational speed Ne2 at the operating point at the intersection of the traveling power Pdrv with the constant curve and the optimal fuel consumption line becomes larger than the rotational speed limit Nelim, The torque Te2 corresponding to the rotational speed limit Nelim in a curve with a constant power Pdrv is larger than the torque Telim. The travel power Pdrv is the product of the rotational speed limit Nelim and the torque Te2 (in FIG. 8, the portion surrounded by the four straight lines x-axis, y-axis, x = Nelim, y = Te2). Even if is output, the power is insufficient by the amount corresponding to the lower hatched portion in FIG. Therefore, it is necessary to operate the engine 22 at the operation point of the rotational speed limit Nelim and the torque Te3. This torque Te3 is obtained by dividing the battery power output Pdrv by subtracting the battery 50 output limit Wout by the rotation speed limit Nelim, and therefore coincides with the target torque Te * in step S190. Therefore, in the processes in steps S190 and S200 to S220 described above, the insufficient power ΔP that is insufficient with respect to the traveling power Pdrv when the engine 22 is operated with the rotational speed limit Nelim and the torque Telim is changed from the battery 50 to the output limit Wout. This is covered by the corresponding power and the increased power by setting the torque of the engine 22 to the torque Te3 which is larger than the torque Telim. Here, a method for increasing the torque of the engine 22 can be performed by advancing the opening / closing timing of the intake valve 128 of the variable valve timing mechanism 150. By such control, it is possible to travel by outputting the traveling power Pdrv to the drive shaft 32 while suppressing a decrease in fuel consumption.

  According to the hybrid vehicle 20 of the embodiment described above, the insufficient power ΔP obtained by subtracting the engine upper limit power Pelim from the traveling power Pdrv while the engine speed limit Nelim is imposed on the engine 22 is the output of the battery 50. When the value is larger than the limit Wout, the rotation speed limit Nelim, which is obtained by subtracting the battery 50 output limit Wout from the traveling power Pdrv with the advance timing of the opening / closing timing of the intake valve 128 by the variable valve timing mechanism 150, is divided by the rotation speed limit Nelim. The engine 22 is operated at the operating point consisting of the torque and the power obtained by subtracting the power corresponding to the output limit Wout of the battery 50 from the traveling power Pdrv is output from the engine 22 and the power corresponding to the output limit Wout is output from the battery 50. Is output and the drive shaft 3 Traveling by controlling so as to run by outputting a power Pdrv, it can run by outputting a driving power Pdrv to the drive shaft 32 while suppressing a decrease in fuel economy.

  Further, according to the hybrid vehicle 20 of the embodiment, the insufficient power ΔP obtained by subtracting the engine upper limit power Pelim from the traveling power Pdrv while the engine speed limit Nelim is imposed on the engine 22 is the output limit of the battery 50. When Wout or less, the engine 22 is operated at an operation point consisting of the rotational speed limit Nelim and the torque Telim on the optimum fuel efficiency line, and the insufficient power ΔP is output from the battery 50 and the traveling power Pdrv is output to the drive shaft 32. By controlling the vehicle to travel, the engine 22 can be operated at the operating point on the optimum fuel efficiency line, and the traveling power Pdrv can be output to the drive shaft 32 to travel.

  In the hybrid vehicle 20 of the embodiment, when the insufficient power ΔP is larger than the output limit Wout of the battery 50, the rotational speed limit Nelim and the traveling power Pdrv are accompanied by the advance angle of the opening / closing timing of the intake valve 128 by the variable valve timing mechanism 150. It is assumed that the engine 22 is operated at an operating point consisting of a torque obtained by dividing the battery 50 output limit Wout by the rotation speed limit Nelim, but only the advance timing of the opening / closing timing of the intake valve 128 by the variable valve timing mechanism 150 Instead, the EGR amount Ve in the EGR system 160 may be changed. In an engine equipped with a supercharger such as a turbocharger or a supercharger, the supercharge rate of the supercharger may be increased.

  In the hybrid vehicle 20 of the embodiment, the power from the motor MG2 is output to the drive shaft 32 connected to the drive wheels 63a and 63b. However, as illustrated in the hybrid vehicle 120 of the modification of FIG. The power from MG2 may be output to an axle (an axle connected to wheels 64a and 64b in FIG. 9) different from an axle to which drive shaft 32 is connected (an axle to which drive wheels 63a and 63b are connected). .

  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 embodiment, the engine 22 having the variable valve timing mechanism 150 corresponds to “engine”, the motor MG1 corresponds to “first motor”, the planetary gear 30 corresponds to “planetary gear mechanism”, and the battery 50 corresponds to “battery”. The HVECU 70 that executes the drive control routine of FIG. 3 and the engine ECU 24 and the motor ECU 40 that control the engine 22 and the motors MG1 and MG2 by transmission from the HVECU 70 correspond to “control 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. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. 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.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

  20,120 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 24a CPU, 24b ROM, 24c RAM, 26 crankshaft, 30 planetary gear, 32 drive shaft, 40 motor electronic control unit (motor ECU) , 41, 42 Inverter, 50 Battery, 62 Differential gear, 63a, 63b Drive wheel, 64a, 64b Wheel, 70 Hybrid electronic control unit, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 122 Air cleaner, 124 Throttle valve, 126 Fuel injection valve, 128 Intake valve 130 spark plug, 132 piston, 134 purification device, 134a temperature sensor, 135a air-fuel ratio sensor, 135b oxygen sensor, 136, throttle motor, 138 ignition coil, 140 crank position sensor, 142 water temperature sensor, 144 cam position sensor, 146 throttle valve Position sensor, 148 air flow meter, 149 temperature sensor, 150 variable valve timing mechanism, 159 knock sensor, 160 EGR system, 162 EGR pipe, 163 stepping motor, 164 EGR valve, 165 EGR valve opening sensor, MG1, MG2 motor.

Claims (1)

Three rotating elements are connected to an engine having a torque increasing mechanism for increasing torque, a first motor capable of generating electricity, an output shaft of the engine, a rotating shaft of the first motor, and a driving shaft connected to an axle. A hybrid vehicle comprising: a planetary gear mechanism; a second motor that inputs and outputs driving power; and a battery that can exchange power with the first motor and the second motor,
On the fuel efficiency priority operation line in which fuel efficiency is given priority in order to output from the engine the traveling power required for traveling of the vehicle while the rotational speed limit for driving the engine at a predetermined rotational speed or less is imposed. When the engine is operated at the time when the engine speed becomes larger than the predetermined engine speed, the engine is operated at an upper limit operation point corresponding to the predetermined engine speed on the fuel consumption priority operation line. When the insufficient power obtained by subtracting the power output from the engine from the driving power when driving is greater than the allowable maximum power that can be output from the battery, the torque increasing mechanism from the engine operating at the predetermined speed The power obtained by subtracting the allowable maximum power from the traveling power with an increase in torque due to Both control means for controlling said engine and said first motor and said second motor so as to run through the traveling power and outputting the maximum allowable power from said battery,
A hybrid car with

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