JP2013193533A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration of emission while achieving improvement in fuel consumption, in a hybrid vehicle.SOLUTION: When a hybrid vehicle is in a predetermined post-start state where there is no history that an engine is started after starting of a system, cooling water temperature Tw is lower than a threshold Twref, and an electricity storage rate SOC of a battery is not less than a threshold Sref (S310 to S330), a greater value, as compared to when the vehicle is not in the predetermined post-start state, is set as a start threshold Pstart based on the electricity storage rate SOC (S340). Then, the start threshold Pstart is used to perform control so that the vehicle travels with torque required for traveling accompanying intermittent engine operation outputted to a drive shaft. Thereby, when the engine is first started after starting of the system, a range for load operation of the engine is enlarged, deterioration in fuel consumption caused by engine idling operation is suppressed, and engine warm-up is promptly completed to suppress deterioration of emission.

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle including an internal combustion engine capable of outputting traveling power and an electric motor capable of outputting traveling power.

  Conventionally, in this type of hybrid vehicle, when the motor can be driven, the preheating of the engine by the preheating device or the preparation of the sensor such as the air-fuel ratio sensor is completed based on the coolant temperature of the engine and the state of the air conditioner switch. An engine that starts an engine after a delay time determined based on completion of warm-up of the exhaust gas purification apparatus has been proposed (see, for example, Patent Document 1). In this hybrid vehicle, the engine is started after the delay time has elapsed, so that the engine is started or the operation immediately after the start is efficiently performed.

  Further, when the temperature of the catalyst of the exhaust purification device attached to the exhaust system of the engine is lower than the temperature T1 required for exhaust gas purification during the engine continuous operation, the catalyst warm-up operation is performed, and the catalyst temperature is the temperature T1 and the engine start. When the temperature is between the temperature T2 (> T1) required for exhaust gas purification at the time and the engine is intermittently prohibited, the engine is intermittently operated. When the catalyst temperature is higher than the temperature T2, the engine is intermittently operated. There are also proposals for performing (see, for example, Patent Document 2). In this hybrid vehicle, by performing such control, deterioration of fuel consumption due to catalyst warm-up is suppressed while suppressing deterioration of emissions.

JP 2004-156581 A JP 2010-058745 A

  As described above, in hybrid vehicles, it is considered as one of the important issues how to operate the engine intermittently in order to suppress the deterioration of emissions and the deterioration of fuel consumption due to catalyst warm-up. ing. For example, if the engine intermittent operation is prohibited when the engine coolant temperature is low, the engine idling operation is continued, resulting in a deterioration in fuel consumption, and the engine intermittent operation when the coolant temperature is low. If this is allowed, the catalyst will not function and the emission will be deteriorated.

  The main purpose of the hybrid vehicle of the present invention is to improve the fuel consumption and suppress the deterioration of the emission.

  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
Vehicle required power including an internal combustion engine capable of outputting driving power, an electric motor capable of outputting driving power, a secondary battery capable of exchanging electric power with the motor, and driving power based on accelerator opening In a hybrid vehicle comprising: a control means for controlling the internal combustion engine and the electric motor so as to travel with charging and discharging of the secondary battery by outputting from the internal combustion engine and the electric motor.
The control means has no history of starting the internal combustion engine after system startup, the cooling water temperature of the internal combustion engine is less than a predetermined temperature threshold, and the total charged amount of charge that can be discharged from the secondary battery Is a predetermined threshold value as a starting threshold value for starting the internal combustion engine with respect to the vehicle required power when the internal combustion engine is intermittently operated. It is means for controlling to travel with intermittent operation of the internal combustion engine using a value of power that is larger than when it is not in a state after startup.
It is characterized by that.

  In the hybrid vehicle of the present invention, there is no history of starting the internal combustion engine after the system is started, the cooling water temperature of the internal combustion engine is less than a predetermined temperature threshold, and the total charged amount of charge that can be discharged from the secondary battery Is a predetermined post-startup state in which the power storage ratio is greater than or equal to a predetermined power storage ratio threshold, the predetermined post-startup state is a start threshold for starting the internal combustion engine with respect to the vehicle required power when the internal combustion engine is intermittently operated. Control is performed so as to travel with intermittent operation of the internal combustion engine using a value of power that is greater than when there is not. That is, it is more difficult to start the internal combustion engine when in the predetermined post-start state than when not in the predetermined post-start state. As a result, it is possible to widen the power range of the electric travel that travels by the power from the electric motor without starting the internal combustion engine, and to extend the duration of the electric travel. For this reason, since the power storage ratio of the secondary battery is reduced by electric travel, when the internal combustion engine is subsequently started, the load operating region of the internal combustion engine is increased, and the frequency of idling operation of the internal combustion engine is decreased. As a result, it is possible to suppress deterioration in fuel consumption due to idling operation of the internal combustion engine. In addition, as a result of increasing the frequency of load operation of the internal combustion engine, the amount of heat generated by the internal combustion engine per unit time increases, and the temperature of the cooling water can be quickly increased. As a result, warm-up can be completed quickly, and emission deterioration can be suppressed. As a result, the fuel consumption can be improved and the deterioration of the emission can be suppressed.

  In such a hybrid vehicle of the present invention, the start threshold value used in the state after the predetermined start-up can be a value of power that increases as the power storage ratio increases. In this way, it is possible to make it difficult to start the internal combustion engine as the power storage ratio increases. In this case, the starting threshold value used in the state after the predetermined activation may be a smaller value as the vehicle speed increases. This is based on the fact that when the internal combustion engine is started, load driving is facilitated because the traveling power increases when the vehicle speed is high. In other words, if the internal combustion engine is continuously loaded, the amount of heat generated by the internal combustion engine per unit time increases, the temperature of the cooling water can be quickly raised, the warm-up is completed quickly, and the emission deteriorates. It is because it can suppress.

  In the hybrid vehicle of the present invention, when the internal combustion engine is started in the state after the predetermined start-up, the predetermined start is used as a stop threshold for stopping the operation of the internal combustion engine with respect to the vehicle required power. It can also be a means for controlling to run with intermittent operation of the internal combustion engine using a power value smaller than that in a non-rear state. When a small value is used as the stop threshold, it becomes difficult to stop the operation of the internal combustion engine. For this reason, since it becomes easy to continue the load operation of the internal combustion engine, the temperature of the cooling water can be quickly raised, and the warm-up of the internal combustion engine can be completed quickly to suppress the deterioration of the emission.

  In the hybrid vehicle of the present invention, the temperature threshold is a value that is predetermined as a lower limit value of a temperature range in which exhaust purification by an exhaust purification device attached to the internal combustion engine functions sufficiently, and the power storage ratio The threshold value may be a value set in advance as an upper limit value of a power storage ratio range in which the frequency with which the secondary battery is required to be charged becomes high. In this way, it is possible to more effectively execute improvement in fuel consumption and suppression of deterioration in emissions.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. 5 is a flowchart illustrating an example of an intermittent operation drive control routine executed by an HVECU 70; 5 is a flowchart illustrating an example of a threshold setting routine 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 as an example of a fuel consumption optimal operation line. It is explanatory drawing which shows an example of the map for predetermined state starting threshold value setting after starting. It is explanatory drawing which shows an example of the normal time starting threshold value setting map. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 420 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 drawing, the hybrid vehicle 20 of the embodiment includes an engine 22 that outputs power using gasoline or light oil as a fuel, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that controls the drive of the engine 22, an engine, and the like. A planetary gear 30 having a carrier connected to a crankshaft 26 as an output shaft 22 and a ring gear connected to a drive shaft 32 connected to drive wheels 38a and 38b via a differential gear 37, for example, a synchronous generator motor Then, the motor MG1 whose rotor is connected to the sun gear of the planetary gear 30, a motor MG2 configured as, for example, a synchronous generator motor and whose rotor is connected to the drive shaft 32, and an inverter 41 for driving the motors MG1 and MG2 , 42 and inverters 41, 42 A motor electronic control unit (hereinafter referred to as a motor ECU) 40 for driving and controlling the motors MG1 and MG2 by switching control of the switching elements, a battery 50 configured as, for example, a lithium ion secondary battery, and inverters 41 and 42 Are connected to a power line (hereinafter referred to as a high voltage system power line) 54a and a power line (hereinafter referred to as a battery voltage system power line) 54b to which the battery 50 is connected. Boost converter 55 that exchanges power with voltage system power line 54b, battery electronic control unit (hereinafter referred to as battery ECU) 52 that manages battery 50, and hybrid electronic that controls the entire drive system of the vehicle A control unit (hereinafter referred to as HVECU) 70 That.

  As shown in FIG. 2, the engine 22 sucks air purified by the air cleaner 122 through the throttle valve 124 and injects gasoline from the fuel injection valve 126 to mix the sucked air and gasoline. The air-fuel mixture is sucked into the fuel chamber via 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. Exhaust gas from the engine 22 is sent to the outside air through a purification device 134 having a purification catalyst (three-way catalyst) 134a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). Discharged.

  Although not shown, the engine ECU 24 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 engine ECU 24 detects signals from various sensors that detect the state of the engine 22, for example, the crank position θcr from the crank position sensor 140 that detects the rotational position of the crankshaft 26 and the coolant temperature of the engine 22. The cam position for detecting the coolant temperature Tw from the water temperature sensor 142, the in-cylinder pressure Pin from the pressure sensor attached to the combustion chamber, and the rotational position of the intake valve 128 for intake and exhaust to the combustion chamber and the camshaft for opening and closing the exhaust valve Cam position θca from sensor 144, throttle opening TH from throttle valve position sensor 146 for detecting the position of throttle valve 124, intake air amount Qa from air flow meter 148 attached to the intake pipe, and also attached to the intake pipe Temperature Intake air temperature Ta from the sensor 149, catalyst temperature Tc from the temperature sensor 134b for detecting the temperature of the purification catalyst 134a, air-fuel ratio AF from the air-fuel ratio sensor 135a attached to the exhaust system, and oxygen sensor also attached to the exhaust system An oxygen signal O2 and the like from 135b is input via the input port. 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 and the control signal to the variable valve timing mechanism 150 that can change the opening / closing timing of the intake valve 128 are output via the output port. The engine ECU 24 communicates with the HVECU 70, controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data related to the operating 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 θcr from the crank position sensor 140.

  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, for example, rotational positions θm1 and θm2 from a rotational position detection sensor (not shown) that detects the rotational position of the rotor of the motors MG1 and MG2, and currents (not shown). A phase current applied to the motors MG1 and MG2 detected by the sensor is input via the input port, and a switching control signal to a switching element (not shown) of the inverters 41 and 42 is output from the motor ECU 40. It is output via. 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, 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 HVECU 70 includes a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, an accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, and a depression amount of the brake pedal 85. The brake pedal position BP from the brake pedal position sensor 86 for detecting the vehicle speed, the vehicle speed V from the vehicle speed sensor 88, the EV switch signal SWEV from the EV switch for instructing electric travel, 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.

  In the hybrid vehicle 20 of the embodiment thus configured, the required torque Tr * to be output to the drive shaft 32 is calculated based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver. The engine 22, the motor MG1, and the motor MG2 are controlled to operate so that the traveling power Pdrv corresponding to the required torque Tr * 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 the traveling power Pdrv is output from the engine 22, and all the power output from the engine 22 is transmitted to the planetary gear 30 and the motor MG1. Torque conversion operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that the torque is converted by the motor MG2 and output to the drive shaft 32, and the sum of the power Pdrv for traveling and the power required for charging and discharging the battery 50 The engine 22 is operated and controlled so that the required vehicle power P * is output from the engine 22, and all or part of the power output from the engine 22 with charging and discharging of the battery 50 is transmitted to the planetary gear 30 and the motor MG1. Traveling power is accompanied by torque conversion by the motor MG2. -Charge / discharge operation mode for driving and controlling the motor MG1 and the motor MG2 so that Pdrv is output to the drive shaft 32, operation for stopping the operation of the engine 22 and outputting the traveling power Pdrv from the motor MG2 to the drive shaft 32 There are motor operation modes to be controlled. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22, the motor MG1, and the motor MG2 are controlled so that the traveling power Pdrv is output to the drive shaft 32 with the operation of the engine 22. Since there is no substantial difference in control, both are hereinafter referred to as an engine operation mode.

  In the engine operation mode, the HVECU 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, and the set required torque Multiply Tr * by the rotational speed Nr of the drive shaft 32 (for example, the rotational speed Nm2 of the motor MG2 or the rotational speed obtained by multiplying the vehicle speed V by a conversion factor) to calculate the traveling power Pdrv required for traveling. By adding the charge / discharge request power Pb * (negative value when discharging from the battery 50) and loss (loss) of the battery 50 obtained based on the travel power Pdrv and the storage ratio SOC of the battery 50, the vehicle The requested vehicle power P * is set. Then, the target rotational speed of the engine 22 is obtained by 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 efficiently output the vehicle required power P * from the engine 22. Ne * and target torque Te * are set, and the rotational speed feedback control is performed so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne * within the range of the input / output limits Win and Wout of the battery 50. A torque command Tm1 * as a torque to be output from the motor MG1 is set, and when the motor MG1 is driven by the torque command Tm1 *, the torque acting on the drive shaft 32 via the planetary gear 30 is subtracted from the required torque Tr *. MG2 torque command Tm2 * is set, and the set target rotational speed Ne * and target torque Te * For 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 * performs intake air amount control and fuel injection control of the engine 22 so that the engine 22 is efficiently operated by the target rotational speed Ne * and the target torque Te *. The motor ECU 40 that performs ignition control and 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 HVECU 70 sets a required torque Tr * to be output to the drive shaft 32 based on the accelerator opening Acc and the vehicle speed V, sets a value 0 to the torque command Tm1 * of the motor MG1, and sets the battery 50. The torque command Tm2 * of the motor MG2 is set and transmitted to the motor ECU 40 so that the required torque Tr * is output to the drive shaft 32 within the range of the input / output limits Win, Wout. 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 hybrid vehicle 20 of the embodiment, when the EV switch 89 is turned on, the operation of the engine 22 is continued until the storage ratio SOC of the battery 50 reaches a threshold value that is predetermined as a value sufficient to start the engine 22. When the EV switch 89 is turned off and the EV switch 89 is turned off, the motor 22 is intermittently operated in accordance with the vehicle required power P * required for the vehicle. Travel by mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation until the engine 22 is started for the first time after the system is started will be described. FIG. 3 is a flowchart showing an example of a drive control routine during intermittent operation executed by the CPU 72 of the HVECU 70 when traveling with intermittent operation of the engine 22, and FIG. 4 is a start threshold value used for drive control during intermittent operation. It is a flowchart which shows an example of the threshold value setting routine which sets Pstart. These routines are repeatedly executed every predetermined time (for example, every several msec). For ease of explanation, first, drive control during intermittent operation will be described using the intermittent operation drive control routine of FIG. 3, and then setting of the start threshold value Pstart using the threshold setting routine of FIG. explain.

  When the intermittent operation drive control routine is executed, first, the CPU 72 of the HVECU 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, and the rotational speeds Nm1, Nm2, of the motors MG1, MG2. Processing for inputting data necessary for control, such as input / output limits Win and Wout of battery 50, storage rate SOC, and cooling water temperature Tw, 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 of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. In addition, the storage rate SOC is calculated from the integrated value of the charge / discharge current Ib detected by the current sensor, and is input from the battery ECU 52 by communication. 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 remaining capacity (SOC) of the battery 50 and input from the battery ECU 52 by communication. The recooling water temperature Tw is detected by the water temperature sensor 142 and input from the engine ECU 24 by communication.

  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 38a and 38b as the required torque for the vehicle based on the input accelerator opening Acc and the vehicle speed V and the required for the vehicle. The required vehicle power P * 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. 5 shows an example of the required torque setting map. The vehicle required power P * is required to charge / discharge the battery 50 based on the traveling power Pdrv obtained by multiplying the set required torque Tr * by the rotational speed Nr of the drive shaft 32 and the storage ratio SOC of the battery 50. It can be calculated as the sum of the required charge / discharge power Pb * and the loss Loss. The rotational speed Nr of the drive shaft 32 can be obtained by multiplying the vehicle speed V by a conversion coefficient k (Nr = k · V) or can be obtained as the rotational speed Nm2 of the motor MG2.

  Subsequently, it is determined whether or not the engine 22 is stopped (step S120). When the engine 22 is stopped, the set vehicle required power P * is equal to or higher than a start threshold Pstart for starting the engine 22. It is determined whether or not (step S130). The start threshold value Pstart is set by the threshold value setting routine of FIG. Details of the start threshold value Pstart will be described later.

  If it is determined in step S130 that the vehicle required power P * is less than the start threshold value Pstart, it is determined that there is no output request to the engine 22, and a value 0 is set in the torque command Tm1 * of the motor MG1 (step S140). ), The required torque Tr * is set in the torque command Tm1 * of the motor MG2 (step S150), the set torque commands Tm1 * and Tm2 * are transmitted to the motor ECU 40 (step S160), and this routine is terminated. Upon receiving the torque commands Tm1 * and Tm2 *, the motor ECU 40 switches the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * having the value 0 and the motor MG2 is driven by the torque command Tm2 *. Take control. Thereby, it is possible to travel by outputting the required torque Tr * from the motor MG2 to the drive shaft 32.

  On the other hand, if it is determined in step S130 that the required vehicle power P * is greater than or equal to the start threshold value Pstart, the engine 22 is started (step S170). The engine 22 is started by outputting torque from the motor MG1 to motoring the engine 22 and performing fuel injection and ignition. During this time, drive control acts on the drive shaft 32 by outputting torque from the motor MG1. The sum of the cancel torque for canceling the torque and the required torque Tr * is output from the motor MG2. Since the details of the control at the time of starting the engine 22 do not form the core of the present invention, further explanation is omitted.

  When the engine 22 is started, the engine 22 is operated based on the predetermined fuel consumption optimum operation line and the set vehicle required power P * as an operation line as a relation between the rotational speed Ne of the engine 22 and the torque Te for optimizing the fuel consumption. A target rotational speed Ne * and a target torque Te * are set as operating points to be operated (step S190), and the target rotational speed Ne * of the engine 22, the rotational speed Nm2 of the motor MG2, and the gear ratio ρ of the planetary gear 30 are determined. Using the following equation (1), the target rotational speed Nm1 * of the motor MG1 is calculated and output from the motor MG1 by the formula (2) based on the calculated target rotational speed Nm1 * and the input rotational speed Nm1 of the motor MG1. The power torque command Tm1 * is calculated (step S200). FIG. 6 shows a state where the target rotational speed Ne * and the target torque Te * are set as an example of the fuel efficiency optimum operation line. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the fuel efficiency optimal operation line and a curve with a constant vehicle required power P * (Ne * × Te *). Expression (1) is a relational expression regarding the mechanical rotational speed of the rotating element of the planetary gear 30, and Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is the gain of the proportional term, and “k2” in the third term on the right side is the gain of the integral term. Note that the first term on the right side of the equation (2) is a torque as a reaction force against the torque acting via the planetary gear 30 when the target torque Te * is output from the engine 22.

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

  Subsequently, a value obtained by dividing the torque command Tm1 * set to the required torque Tr * by the gear ratio ρ of the planetary gear 30 is added, and a temporary torque Tm2tmp, which is a temporary value of torque to be output from the motor MG2, is expressed by the following equation (3). (Step S210), and the deviation between the power consumption (generated power) of the motor MG1 obtained by multiplying the input / output limits Win, Wout of the battery 50 and the torque command Tm1 * by the current rotational speed Nm1 of the motor MG1 is calculated. Torque limits Tmin and Tmax as upper and lower limits of the torque that may be output from the motor MG2 by dividing by the rotational speed Nm2 of MG2 are calculated by the following equations (4) and (5) (step S220) and set. Temporary torque Tm2tmp is limited by torque limits Tmin and Tmax according to equation (6), and torque command T of motor MG2 is set. Setting the 2 * (step S230).

Tm2tmp = Tr * + Tm1tmp / ρ (3)
Tmin = (Win-Tm1 * ・ Nm1) / Nm2 (4)
Tmax = (Wout-Tm1 * ・ Nm1) / Nm2 (5)
Tm2 * = max (min (Tm2tmp, Tmax), Tmin) (6)

  The set target rotational speed Ne * and the target torque Te * are transmitted to the engine ECU 24, and the set torque commands Tm1 * and Tm2 * are transmitted to the motor ECU 40 (step S230), and this routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * controls the intake air amount in the engine 22 so that the engine 22 is operated at the operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as fuel injection control and ignition control. 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. As a result, the engine 22 can be efficiently operated within the range of the input / output limits Win and Wout of the battery 50 to output the required torque Tr * to the drive shaft 32 and travel.

  If it is determined in step S120 that the engine 22 is in operation, it is determined whether the vehicle required power P * is less than a stop threshold value Pstop for stopping the operation of the engine 22 (step S180). Here, as the stop threshold value Pstop, a value determined in advance so as to have hysteresis with respect to the start threshold value Pstart is used so that the engine 22 is not frequently started and stopped. If it is determined that the vehicle required power P * is equal to or greater than the stop threshold value Pstop, it is determined that the output request to the engine 22 is continued, and the processing in the engine operation mode, that is, the processing of steps S190 to S230 is executed. This routine ends. On the other hand, when it is determined that the vehicle required power P * is less than the stop threshold value Pstop, the operation of the engine 22 is stopped (step S240), and the processing in the motor operation mode, that is, the processing in steps S140 to S160 is executed. End the routine.

  Next, processing for setting the start threshold value Pstart using the threshold value setting routine of FIG. 4 will be described. When the threshold setting routine is executed, the CPU 72 of the HVECU 70 first inputs data necessary for setting the starting threshold Pstart such as the vehicle speed V from the vehicle speed sensor 88, the storage ratio SOC of the battery 50, and the cooling water temperature Tw. (Step S300), whether or not there is a history of starting the engine 22 after starting the system (Step S310), whether or not the cooling water temperature Tw is less than the threshold value Twref (Step S320), and the storage ratio SOC is equal to or greater than the threshold value Sref (Step S330). The threshold value Twref is determined in advance as a lower limit value of the temperature range of the cooling water that reaches the temperature range in which the purification catalyst 134a of the purification device 134 is activated and functions sufficiently. For example, the threshold value Twref is 45 ° C., 50 ° C., 55 C. etc. can be used. The threshold value Sref is determined in advance as an upper limit value in the range of the power storage ratio SOC at which the frequency at which the battery 50 is requested to be charged is high. For example, 40% or 50% can be used.

  When there is no history of starting the engine 22 after the system is started, the coolant temperature Tw is less than the threshold value Twref, and the power storage rate SOC is equal to or higher than the threshold value Sref, the power storage rate SOC tends to increase as the power storage rate SOC increases. Is set as the start threshold value Pstart (step S340), the routine is terminated, and there is a history of starting the engine 22 after starting the system, the cooling water temperature Tw is equal to or higher than the threshold value Twref, or the storage ratio SOC Is less than the threshold value Sref, that is, when the vehicle is not in the predetermined post-start state, a value that tends to decrease as the vehicle speed V increases and is smaller than the start threshold value Pstart is set as the start threshold value Pstart (step S350). End the routine. Here, the start threshold value Pstart in the state after the predetermined start-up is stored in the ROM 74 as a predetermined post-start-up state start threshold setting map by predetermining the relationship between the power storage ratio SOC and the start threshold value Pstart in the embodiment. When the power storage rate SOC is given, the corresponding start threshold value Pstart is derived from the map. An example of the state startup threshold value setting map after predetermined activation is shown in FIG. As shown in the figure, the start threshold value Pstart is set so as to increase as the power storage rate SOC increases within a range equal to or greater than the threshold value Sref. In addition, in the embodiment, the start threshold value Pstart when not in the predetermined post-start state is determined by storing the relationship between the vehicle speed V and the start threshold value Pstart in advance in the ROM 74 as a normal start threshold value setting map. If so, the corresponding starting threshold value Pstart is derived from the map. An example of the normal start threshold setting map is shown in FIG. As shown in the figure, the starting threshold value Pstart is set so as to decrease as the vehicle speed V increases. “Pmax” in FIG. 7 and FIG. 8 is the maximum value of the starting threshold value Pstart set in the normal starting threshold value setting map. Therefore, the starting threshold value Pstart in the predetermined post-start state is the normal starting threshold value setting. It becomes larger than the starting threshold value Pstart set in the work map. Thus, setting the start threshold value Pstart when in the predetermined post-start state to be larger than the start threshold value Pstart when not in the predetermined post-start state makes it difficult to start the engine 22 until the storage ratio SOC becomes relatively small. Because. That is, the power range of the electric travel that travels with the power from the motor MG2 without starting the engine 22 (the region where the vehicle required power P * is less than the start threshold Pstart) is widened to increase the duration of the electric travel, The engine 22 is started after the storage ratio SOC becomes small. As a result, when the engine 22 is started, a charge request for the battery 50 is generated because the storage ratio SOC is small, and a relatively large charge / discharge request power Pb * is set. Therefore, the engine 22 at the driving power Pdrv is loaded. The area where the vehicle required power P * is greater than or equal to the stop threshold value Pstop is increased, and the frequency of idling operation of the engine 22 is decreased. As a result, it is possible to suppress the deterioration of fuel consumption due to the idling operation of the engine 22. Further, since the frequency of the engine 22 being loaded is increased, the amount of heat generated by the engine 22 per unit time is increased as compared with the idling operation, and the temperature Tw of the cooling water can be quickly increased. As a result, warm-up of the engine 22 and warm-up of the purification catalyst 134a of the purification device 134 can be completed quickly, and emission deterioration can be suppressed.

  According to the hybrid vehicle 20 of the embodiment described above, there is no history of starting the engine 22 after starting the system, the cooling water temperature Tw is less than the threshold value Twref, and the predetermined post-startup state in which the storage ratio SOC is equal to or higher than the threshold value Sref. Is set as a starting threshold value Pstart as compared to when the engine is not in a predetermined post-start state, and the required torque Tr * is increased with intermittent operation of the engine 22 using the starting threshold value Pstart and the stop threshold value Pstop. When the engine 22 is started for the first time after the system is started by controlling to output to the drive shaft 32, the area where the engine 22 is subjected to load operation is enlarged, and deterioration of fuel consumption due to idling operation of the engine 22 is suppressed. can do. Further, since the frequency of load operation of the engine 22 increases, the temperature Tw of the cooling water can be quickly raised, and the warming up of the engine 22 and the purification catalyst 134a of the purification device 134 can be completed quickly. Deterioration of emissions can be suppressed. In addition, since the start threshold value Pstart is set so as to increase as the power storage ratio SOC increases in the state after the predetermined start-up, the engine 22 can be made difficult to start as the power storage ratio SOC increases.

  In the hybrid vehicle 20 of the embodiment, the start threshold value Pstart is set so as to increase as the power storage ratio SOC of the battery 50 increases when the hybrid vehicle 20 is in a predetermined post-startup state, but increases as the power storage ratio SOC of the battery 50 increases. The starting threshold value Pstart may be set so that the vehicle speed V tends to decrease as the vehicle speed V increases. For example, the starting threshold value Pstart derived for the power storage ratio SOC using the map of FIG. 7 is set as the temporary threshold value P1, and the starting threshold value Pstart derived for the vehicle speed V using the map of FIG. A value obtained by dividing the value by setting as a coefficient k and setting a value obtained by multiplying the provisional threshold value P1 and the coefficient k as the starting threshold value Pstart can be considered. Here, when the vehicle speed V increases, the start threshold value Pstart is set so as to decrease as the vehicle speed V increases, and the engine 22 is started because the traveling power Pdrv increases when the vehicle speed V increases. Based on the increased frequency of continuation of load operation. As described above, the frequency of continuation of the load operation of the engine 22 is increased, so that the temperature Tw of the cooling water can be quickly raised, and the engine 22 can be quickly warmed up and the purification catalyst 134a of the purification device 134 can be warmed up quickly. The machine can be completed and the deterioration of emissions can be suppressed.

  In the hybrid vehicle 20 of the embodiment, the start threshold value Pstart is set so as to increase as the power storage ratio SOC of the battery 50 increases when the hybrid vehicle 20 is in a predetermined post-start state. Since it is only necessary to set a starting threshold value Pstart having a larger value than when not in a state, a constant value may be set as the starting threshold value Pstart regardless of the storage ratio SOC.

  In the hybrid vehicle 20 of the embodiment, when the state is in the predetermined post-start state, the driving control is performed by setting a large value as the start threshold value Pstart compared to when not in the predetermined post-start state. When the engine 22 is started in the predetermined post-start state, the drive control may be performed by setting a smaller value as the stop threshold value Pstop than when the engine 22 is not in the predetermined post-start state. This is based on the fact that it is preferable to continue the load operation of the engine 22 for a long time when the engine 22 is started in the state after the predetermined activation. That is, it is difficult to stop the engine 22 by setting a small value as the stop threshold value Pstop and performing drive control. Thereby, the continuation of the load operation of the engine 22 can be lengthened and the temperature Tw of the cooling water can be quickly raised, and the warming up of the engine 22 and the warming up of the purification catalyst 134a of the purification device 134 are completed quickly. This can suppress the deterioration of emissions.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is output to the drive shaft 32. However, as illustrated in the hybrid vehicle 120 of the modification of FIG. 9, the drive shaft 32 is connected to the power of the motor MG2. It may be connected to an axle (an axle connected to the drive wheels 39a and 39b in FIG. 9) different from the other axle (an axle to which the drive wheels 38a and 38b are connected). Further, in the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the drive shaft 32 connected to the drive wheels 38a and 38b via the planetary gear 30, but the hybrid vehicle 220 of the modified example of FIG. As illustrated, an inner rotor 232 connected to the crankshaft of the engine 22 and an outer rotor 234 connected to the drive shaft 32 that outputs power to the drive wheels 38a and 38b, and a part of the power of the engine 22 To the drive shaft 32 and a counter-rotor motor 230 that converts the remaining power into electric power.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 32 connected to the drive wheels 38a and 38b via the planetary gear 30, and the power from the motor MG2 is output to the drive shaft 32. However, as illustrated in the hybrid vehicle 320 of the modified example of FIG. 11, a motor MG is attached to the drive shaft 32 connected to the drive wheels 38a and 38b via the transmission 330, and a clutch 329 is attached to the rotation shaft of the motor MG. The power from the engine 22 is output to the drive shaft 32 via the rotating shaft of the motor MG and the transmission 330, and the power from the motor MG is driven to the drive shaft via the transmission 330. It is good also as what outputs to. Alternatively, as illustrated in the hybrid vehicle 420 of the modified example of FIG. 12, the power from the engine 22 is output to the drive shaft 32 connected to the drive wheels 38a and 38b via the transmission 430 and the power from the motor MG. May be output to an axle different from the axle to which the drive wheels 38a, 38b are connected (the axle connected to the wheels 39a, 39b in FIG. 12). That is, any type of hybrid vehicle may be used as long as it is a type of hybrid vehicle that can be electrically driven.

  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 corresponds to the “internal combustion engine”, the motor MG2 corresponds to the “electric motor”, the battery 50 corresponds to the “secondary battery”, and the HVECU 70, the engine ECU 24, the motor ECU 40, and the battery ECU 52 are “ It corresponds 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), 26 crankshaft, 30 planetary gear, 32 drive shaft, 37 differential gear, 38a, 38b drive wheel, 39a, 39b wheel, 40 motor electronics Control unit (motor ECU), 41, 42 Inverter, 50 battery, 52 Electronic control unit for battery (battery ECU), 70 Electronic control unit for hybrid (HVECU), 80 Ignition switch, 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, 89 EV switch, 122 Air cleaner , 124 throttle valve, 126 fuel injection valve, 128 intake valve, 130 spark plug, 132 piston, 134 purification device, 134a purification catalyst, 134b 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, MG1, MG2 motor.

Claims (5)

Vehicle required power including an internal combustion engine capable of outputting driving power, an electric motor capable of outputting driving power, a secondary battery capable of exchanging electric power with the motor, and driving power based on accelerator opening In a hybrid vehicle comprising: a control means for controlling the internal combustion engine and the electric motor so as to travel with charging and discharging of the secondary battery by outputting from the internal combustion engine and the electric motor.
The control means has no history of starting the internal combustion engine after system startup, the cooling water temperature of the internal combustion engine is less than a predetermined temperature threshold, and the total charged amount of charge that can be discharged from the secondary battery Is a predetermined threshold value as a starting threshold value for starting the internal combustion engine with respect to the vehicle required power when the internal combustion engine is intermittently operated. It is means for controlling to travel with intermittent operation of the internal combustion engine using a value of power that is larger than when it is not in a state after startup.
A hybrid vehicle characterized by that. The hybrid vehicle according to claim 1,
The starting threshold value used in the state after the predetermined activation is a value of power that is larger as the power storage ratio is larger.
A hybrid vehicle characterized by that. A hybrid vehicle according to claim 2,
The hybrid vehicle according to claim 1, wherein the starting threshold value used in the predetermined post-startup state is a smaller value as the vehicle speed is higher. A hybrid vehicle according to any one of claims 1 to 3,
When the internal combustion engine is started in the predetermined post-start state, the control means is set as a stop threshold for stopping the operation of the internal combustion engine with respect to the vehicle required power as compared to when the predetermined post-start state is not set. It is means for controlling to travel with intermittent operation of the internal combustion engine using a small power value.
A hybrid vehicle characterized by that. A hybrid vehicle according to any one of claims 1 to 4,
The temperature threshold is a value determined in advance as a lower limit value of a temperature range in which exhaust gas purification by an exhaust gas purification device attached to the internal combustion engine functions sufficiently,
The power storage ratio threshold is a value predetermined as an upper limit value of a power storage ratio range in which the frequency with which the secondary battery is required to be charged is high.
A hybrid vehicle characterized by that.