JP2014189080A - Hybrid car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid car in which starting of an engine is more appropriately determined in accordance with a travelling state of the car.SOLUTION: The hybrid car, when power Pv required by the car is equal to the threshold Pref1 or more and less than the threshold Pref2, calculates an excess integrated value Pov as an integrated value obtained by subtracting the threshold Pref 1 from the power Pv required by the car (S130); sets the threshold Pj for determination that has a tendency to become larger as car speed V becomes higher and a tendency to become larger as the power accumulation ratio SOC of a battery becomes larger (step S150); and when the excess integrated value Pov reaches the threshold Pj for determination or more, determines that an engine should be started (S170 and S190). This allows determination on starting of the engine to be more appropriately performed in accordance with the car speed V and the power accumulation ratio SOC of the battery.

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle equipped with an engine, a motor, and a battery.

  Conventionally, this type of hybrid vehicle integrates the engine start request degree obtained by fuzzy determination based on the motor required power and the accelerator opening change rate when the motor is operated independently (EV travel mode). There has been proposed an apparatus that determines that there is an engine start request when the value is higher than a predetermined threshold (see, for example, Patent Document 1). In this hybrid vehicle, an engine start request is determined by the above-described method, thereby preventing unnecessary operation of the engine and enabling more accurate control based on the driver's will.

International Publication No. 2011/078189

  However, in the above-described hybrid vehicle, the engine start request is determined when the integral value of the engine start request level is higher than a predetermined threshold value. Therefore, depending on the traveling state of the vehicle, the engine start determination may be incompatible. Occurs. For example, when the vehicle is traveling at a relatively high vehicle speed, since the power required for traveling is large, the integral value of the engine start request level easily exceeds the threshold value, and unnecessary engine start is performed. End up. In addition, a complicated calculation such as the use of fuzzy determination for calculating the engine start request degree results in an increase in calculation load.

  The main purpose of the hybrid vehicle of the present invention is to determine the start of the engine more appropriately according to the running state of the vehicle.

  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
A hybrid vehicle equipped with an engine, a motor, and a battery capable of exchanging electric power with the motor,
When a request parameter related to a travel request by a driver is greater than or equal to a predetermined value during motor travel that travels with power from the motor while the engine is stopped, a threshold value for determination is set to increase as the vehicle speed increases. A start determination means for determining start of the engine when an integration parameter that is integrated when the required parameter is equal to or greater than the predetermined value reaches a threshold for determination;
It is characterized by providing.

  In the hybrid vehicle of the present invention, when the request parameter related to the travel request by the driver during motor travel is greater than or equal to a predetermined value, the determination threshold is set such that the higher the vehicle speed is, the greater the request parameter is. When the integration parameter integrated at this time reaches or exceeds the determination threshold, engine start is determined. Since the engine start is determined using the determination threshold value that increases as the vehicle speed increases, the engine start can be made in accordance with the running state of the vehicle, and a more appropriate engine start determination can be made. Can be done.

  Here, as the required parameters, for example, the accelerator opening, the required driving force based on the accelerator opening, the required driving force based on the accelerator opening and the vehicle speed, and the driving based on the rotation speed and the required driving force based on the vehicle speed. Vehicle required power as the sum of power, power for traveling and power required for charging / discharging of the battery can be used. As the integration parameter, for example, an integration amount of a difference between the request parameter and a predetermined value, an elapsed time after the request parameter reaches a predetermined value or more, and the like can be used.

  In such a hybrid vehicle of the present invention, the integration parameter is a parameter that is added when the required parameter is equal to or greater than the predetermined value, and is subtracted within a range up to 0 when the required parameter is less than the predetermined value. It can also be. In this way, since it is considered when the required parameter is less than the predetermined value, the engine start can be determined more appropriately.

  Further, in the hybrid vehicle of the present invention, the start determination means is a means for setting the determination threshold value so as to increase as the storage ratio, which is the ratio of the storage capacity to the total capacity of the battery, increases. You can also. If it carries out like this, the engine starting can be determined more appropriately in consideration of the storage ratio of the battery.

  Furthermore, in the hybrid vehicle of the present invention, the start determination unit may be a unit that sets a value of 0 to the determination threshold when the temperature of the battery is equal to or higher than a predetermined temperature. In this way, the engine can be started quickly when the temperature of the battery is equal to or higher than the predetermined temperature.

  Alternatively, in the hybrid vehicle of the present invention, the start determination means may be configured such that the integrated parameter is less than the determination threshold when the required parameter reaches a second predetermined value greater than the predetermined value while the motor is running. Can also be means for determining the start of the engine. In this way, the engine can be started immediately when the required parameter is larger than the second predetermined value.

  The hybrid vehicle of the present invention only needs to be equipped with an engine, a motor, and a battery capable of exchanging electric power with the motor. For example, the engine, a motor for power generation, an output shaft of the engine, and power generation Planetary gear mechanism in which three rotating elements are connected to a rotating shaft of a motor for driving and a driving shaft connected to an axle, a driving motor connected to the driving shaft, and a power generation motor and a driving motor for exchanging electric power Connected to the engine, a transmission connected to the output shaft of the engine via a clutch and connected to the drive shaft connected to the axle, and connected to the input shaft or output shaft of the transmission A drive motor, a configuration including a battery that exchanges power with the drive motor, an engine, a generator attached to the output shaft of the engine, and an axle. And motors, and configuration and a battery for performing a generator or a motor and the power exchange, it is possible to use various configurations.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 5 is a flowchart showing an example of an engine start determination processing routine executed by an HVECU 70. It is explanatory drawing which shows an example of the relationship between the vehicle speed V and the threshold value for determination Pj. It is explanatory drawing which shows an example of the relationship between the electrical storage ratio SOC of a battery, and the threshold value for determination Pj. It is explanatory drawing which shows an example of the time change of the vehicle request | requirement power Pv and the excess integration value Pov. 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.

  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 FIG. 1, the hybrid vehicle 20 of the embodiment includes an engine 22 that outputs power using gasoline, light oil, or the like as a fuel, and an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that drives and controls the engine 22. A planetary gear 30 in which a carrier is connected to the crankshaft 26 of the engine 22 and a ring gear is connected to a drive shaft 36 connected to the front wheels 38a and 38b via a differential gear 37, and is configured as, for example, a synchronous generator motor and rotates. A motor MG1 whose child is connected to the sun gear of the planetary gear 30, a motor MG2 configured as, for example, a synchronous generator motor and having a rotor connected to the drive shaft 36, and inverters 41 and 42 for driving the motors MG1 and MG2. Configured as, for example, a lithium ion secondary battery The battery 50 is connected to a power line to which the inverters 41 and 42 are connected (hereinafter referred to as a drive voltage system power line 54a) and a power line to which the battery 50 is connected (hereinafter referred to as a battery voltage system power line 54b). Boost converter that adjusts voltage VH of drive voltage system power line 54a in a range not less than voltage VL of battery voltage system power line 54b, and exchanges power between drive voltage system power line 54a and battery voltage system power line 54b 55, a motor electronic control unit (hereinafter referred to as a motor ECU) 40 that controls the drive of the motors MG1 and MG2 and controls the boost converter 55 by controlling the inverters 41 and 42, and a battery electronic that manages the battery 50 A control unit (hereinafter referred to as a battery ECU) 52 and the entire vehicle Gosuru hybrid electronic control unit (hereinafter, referred to HVECU) includes a 70.

  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 receives signals from various sensors that detect the operating state of the engine 22, for example, a water temperature sensor that detects the crank position θcr from the crank position sensor that detects the rotational position of the crankshaft 26 and the coolant temperature of the engine 22. From the cam position sensor for detecting the cooling water temperature Tw from the cylinder, the in-cylinder pressure Pin from the pressure sensor installed in the combustion chamber, the rotational position of the intake valve for intake and exhaust to the combustion chamber and the camshaft for opening and closing the exhaust valve Position θca, throttle position TP from a throttle valve position sensor that detects the position of the throttle valve, intake air amount Qa from an air flow meter attached to the intake pipe, intake air temperature Ta from a temperature sensor also attached to the intake pipe, Installed in the exhaust system The air-fuel ratio AF from the air-fuel ratio sensor and the oxygen signal O2 from the oxygen sensor attached to the exhaust system are input via the input port, and the engine ECU 24 is for driving the engine 22. Various control signals, such as the drive signal to the fuel injection valve, the drive signal to the throttle motor that adjusts the throttle valve position, the control signal to the ignition coil integrated with the igniter, and the opening / closing timing of the intake valve can be changed A control signal to the variable valve timing mechanism is output via the output port. The engine ECU 24 is in communication 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 operation state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26.

  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). The phase current applied to the motors MG1 and MG2 detected by the sensor, the drive voltage system voltage VH from the voltage sensor (not shown) attached to the drive voltage system power line 54a and the battery voltage system power line 54b (not shown) The battery voltage system voltage VL or the like from the voltage sensor is input via the input port. From the motor ECU 40, the switching control signal to the switching elements of the inverters 41 and 42 and the switching control signal to the switching element of the boost converter 55 are input. Etc. are output via 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, 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 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 a required torque to be output to the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount 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 36. 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. The motor MG2 converts the torque of the motor MG1 and the motor MG2 so that the motor MG1 and the motor MG2 are driven and controlled, and the power suitable for the sum of the required power and the power required for charging and discharging the battery 50 is 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 36. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled, and motor operation mode (EV travel mode) in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the drive shaft 36. and so on. 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 36 with the operation of the engine 22. Since there is no difference in the control, hereinafter, both are collectively referred to as an engine operation mode (HV travel mode).

  In the engine operation mode (HV travel mode), the HVECU 70 sets the required torque Tr * to be output to the drive shaft 36 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 36 (for example, the rotational speed obtained by multiplying the rotational speed Nm2 of the motor MG2 by the conversion coefficient or the rotational speed obtained by multiplying the vehicle speed V by the conversion coefficient). 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 a required vehicle power Pv required for the vehicle, and the required vehicle power Pv is efficiently set to the engine 22. A target rotational speed Ne * and a target torque Te * of the engine 22 are set using an operation line (for example, a fuel efficiency optimal operation line) as a relationship between the rotational speed Ne of the engine 22 and the torque Te that can be output from The rotational speed Ne of the engine 22 is set to the target rotational speed Ne * 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 be charged / discharged. The torque command Tm1 * as the torque to be output from the motor MG1 is set by the rotational speed feedback control so that the motor MG1 is driven, and when the motor MG1 is driven by the torque command Tm1 *, it is applied to the drive shaft 36 via the planetary gear 30. The torque command Tm2 * of the motor MG2 is set by subtracting the acting torque from the required torque Tr *, For 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, and the like. 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 motor operation mode (EV travel mode), the HVECU 70 sets the required torque Tr *, the travel power Pr *, and the vehicle required power Pv as in the engine operation mode, and sets the torque command Tm1 * of the motor MG1 to 0. 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 36 within the range of the input / output limits Win and Wout of the battery 50. 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 *.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when determining the start of the engine 22 when traveling in the motor operation mode (EV travel mode) will be described. FIG. 2 is a flowchart showing an example of an engine start determination process routine executed by the HVECU 70. This routine is repeatedly executed at predetermined time intervals (for example, every several tens of msec) while traveling in the motor operation mode (EV travel mode).

  When the engine start determination processing routine is executed, the HVECU 70 is first required for determination of engine start such as the vehicle required power Pv, the vehicle speed V from the vehicle speed sensor 88, the temperature Tb of the battery 50, and the storage ratio SOC of the battery 50. A process of inputting data is executed (step S100). Here, the vehicle required power Pv is input as set by a drive control routine (not shown) by the method described in the drive control in the engine operation mode and the motor operation mode described above. The temperature Tb and the storage rate SOC of the battery 50 are input from the battery ECU 52 by communication.

  Next, the input vehicle request power Pv is compared with the threshold value Pref1 and the threshold value Pref2 (steps S110 and S120). The threshold value Pref1 is predetermined as a threshold value for determining that the engine 22 should be started soon. The threshold value Pref2 is determined in advance as a value larger than the threshold value Pref1 as a threshold value for determining that the engine 22 should be started immediately. Therefore, when the vehicle required power Pv is equal to or greater than the threshold value Pref2, it is determined that the engine 22 should be started immediately, the value 1 is set to the engine start flag Fstart (step S190), and the excess integrated value Pov is initialized to the value 0. (Step S200), this routine is finished. Here, the excess integrated value Pov is a parameter integrated in this routine.

  When the vehicle required power Pv is greater than or equal to the threshold value Pref1 but less than the threshold value Pref2, the vehicle required power Pv is subtracted from the threshold value Pref1, that is, the excess excess value Pov is subtracted from the vehicle required power Pv to the threshold value Pref1. A new excess integrated value Pov is calculated by adding the values (step S130), and it is determined whether or not the temperature Tb of the battery 50 is lower than a predetermined temperature Tbref (step S140). Here, the predetermined temperature Tbref is predetermined as a temperature that is somewhat lower than the allowable upper limit temperature of the battery 50. When the temperature Tb of the battery 50 is lower than the predetermined temperature Tbref, the determination threshold value Pj is set based on the vehicle speed V and the storage ratio SOC of the battery 50 (step S150), and the excess integrated value Pov and the determination threshold value Pj are set. In comparison (step S170), when the excess integrated value Pov is less than the determination threshold value Pj, it is determined that the engine 22 should not be started yet, and this routine is ended. When the excess integration value Pov is greater than or equal to the determination threshold value Pj Then, it is determined that the engine 22 should be started, the value 1 is set to the engine start flag Fstart (step S190), the excess integrated value Pov is initialized to the value 0 (step S200), and this routine is finished. Here, in the embodiment, the determination threshold value Pj previously stores the relationship between the vehicle speed V, the power storage ratio SOC, and the determination threshold value Pj as a determination threshold setting map, and the vehicle speed V and the power storage ratio SOC are determined as follows. When given, it is set by deriving a corresponding determination threshold value Pj from the map. FIG. 3 shows an example of the relationship between the vehicle speed V and the determination threshold value Pj, and FIG. 4 shows an example of the relationship between the power storage ratio SOC and the determination threshold value Pj. As shown in FIG. 3, the relationship between the vehicle speed V and the determination threshold value Pj is a relationship in which the determination threshold value Pj tends to increase as the vehicle speed V increases, and the relationship between the storage ratio SOC and the determination threshold value Pj is As shown in FIG. 4, there is a relationship in which the determination threshold value Pj tends to increase as the power storage ratio SOC increases. As described above, by determining the start of the engine 22 using the determination threshold value Pj according to the vehicle speed V and the storage ratio SOC of the battery 50, the determination of the start of the engine 22 can be performed more appropriately.

  If it is determined in step S140 that the temperature Tb of the battery 50 is equal to or higher than the predetermined temperature Tbref, the determination threshold value Pj is set to 0 (step S160), and the excess integrated value Pov is compared with the determination threshold value Pj ( Step S170). At this time, since the determination threshold value Pj is set to a value of 0 and the excess integrated value Pov is greater than or equal to the value 0, the excess integrated value Pov is determined to be greater than or equal to the determination threshold value Pj and the engine 22 is started. The engine start flag Fstart is set to 1 (step S190), the excess integrated value Pov is initialized to 0 (step S200), and this routine is terminated. Thus, when the temperature Tb of the battery 50 is equal to or higher than the predetermined temperature Tbref, the engine 22 can be quickly started to reduce the load on the battery 50, and further increase in the temperature Tb of the battery 50 can be suppressed. The fact that the excess integrated value Pov is 0 or more will be described later.

  If it is determined in step S110 that the vehicle required power Pv is less than the threshold value Pref1, it is determined that starting of the engine 22 is not necessary, and the sum of the vehicle request power Pv and the threshold value Pref1 subtracted (ie, the excess integrated value so far) A value obtained by adding a value obtained by subtracting the threshold value Pref1 from the vehicle required power Pv to Pov to calculate a new excess integrated value Pov) and a value 0 is set as the excess integrated value Pov (step S180). This routine ends. In this case, since the sum of the vehicle required power Pv minus the threshold value Pref1 is a negative value obtained by subtracting the threshold value Pref1 from the vehicle required power Pv, the threshold value from the vehicle required power Pv is increased to the threshold value. The new excess integrated value Pov is calculated by subtracting the absolute value of the value obtained by subtracting Pref1. Then, by setting the larger one of the new excess integration value Pov and the value 0 calculated in this way as the excess integration value Pov, the excess integration value Pov does not become a negative value, that is, the value 0 or more. It is.

  FIG. 5 is an explanatory diagram illustrating an example of a temporal change in the vehicle required power Pv and the excess integrated value Pov in the hybrid vehicle 20 according to the embodiment. In the figure, the solid line represents the time change of the vehicle required power Pv and the excess integrated value Pov when the amount of depression of the accelerator pedal 83 is severe, and the one-dot chain line represents the vehicle required power when the accelerator pedal 83 is depressed relatively large. It is a time change of Pv and the excess integrated value Pov, and a two-dot chain line is a time change of the vehicle required power Pv and the excess integrated value Pov when the accelerator pedal 83 is depressed to an intermediate level. When the change in the amount of depression of the accelerator pedal 83 is severe (solid line), the excess integrated value Pov increases from the time T11 when the vehicle required power Pv becomes equal to or greater than the threshold value Pref1, but immediately thereafter, the vehicle required power is returned by the return of the accelerator pedal 83. Pv becomes less than the threshold value Pref1, and the excess integrated value Pov becomes 0 without reaching the determination threshold value Pj. The excess integrated value Pov again increases from time T12 when the vehicle required power Pv becomes equal to or greater than the threshold value Pref1, but the vehicle required power Pv becomes less than the threshold value Pref1 by the return of the accelerator pedal 83, and the excess integrated value Pov is the threshold value for judgment Pj. The value becomes 0 without reaching. In the case of this solid line, the engine 22 is not started. When the accelerator pedal 83 is depressed relatively large (dashed line), the excess integrated value Pov increases from time T21 when the vehicle required power Pv becomes equal to or greater than the threshold value Pref1, but the excess integrated value Pov reaches the determination threshold value Pj. The engine 22 is started at time T22 when the previous vehicle required power Pv becomes equal to or greater than the threshold value Pref2, and the excess integrated value Pov is initialized (value 0). When the accelerator pedal 83 is depressed moderately (two-point difference line), the excess integrated value Pov increases from time T31 when the vehicle required power Pv becomes equal to or greater than the threshold value Pref1, and the excess integrated value Pov becomes equal to or greater than the determination threshold value Pj. At time T32, the engine 22 is started, and the excess integrated value Pov is initialized (value 0).

  According to the hybrid vehicle 20 of the embodiment described above, when the vehicle required power Pv is greater than or equal to the threshold value Pref1 and less than the threshold value Pref2 while traveling in the motor operation mode (EV travel mode), the vehicle required power Pv is determined. The excess integrated value Pov, which is the integrated value of the value obtained by subtracting the threshold value Pref1, has reached or exceeded the determination threshold value Pj set to increase as the vehicle speed V increases and to increase as the storage ratio SOC of the battery 50 increases. When it is determined that the engine 22 should be started sometimes, the determination of the start of the engine 22 can be made more appropriately according to the vehicle speed V and the power storage ratio SOC. In addition, when the vehicle required power Pv is equal to or greater than the threshold value Pref2, it is determined that the engine 22 should be started immediately, so that a delay in starting the engine 22 can be suppressed. Further, when the temperature Tb of the battery 50 is equal to or higher than the predetermined temperature Tbref, by setting the value 0 for the determination threshold value Pj, the engine 22 is quickly started to reduce the load of the battery 50, and the temperature Tb of the battery 50 is further increased. The rise can be suppressed.

  In the hybrid vehicle 20 of the embodiment, the determination threshold value Pj is set based on the vehicle speed V and the storage rate SOC of the battery 50. However, the determination threshold value Pj is set based only on the vehicle speed V without using the storage rate SOC. It may be set.

  In the hybrid vehicle 20 of the embodiment, when the temperature Tb of the battery 50 is equal to or higher than the predetermined temperature Tbref, the determination threshold value Pj is set to 0. However, the determination threshold value Pj is not set based on the temperature Tb of the battery 50. It may be a thing.

  In the hybrid vehicle 20 of the embodiment, when the vehicle required power Pv is less than the threshold value Pref1, a new excess obtained by subtracting the absolute value of the vehicle required power Pv minus the threshold value Pref1 from the previous excess integrated value Pov. The larger of the integrated value Pov and the value 0 is set as the excess integrated value Pov, but the excess integrated value Pov may be initialized to the value 0.

  In the hybrid vehicle 20 of the embodiment, when the vehicle required power Pv is greater than or equal to the threshold value Pref1 and less than the threshold value Pref2, the excess integrated value Pov that is the integrated value of the vehicle required power Pv minus the threshold value Pref1 is the vehicle speed V or the battery 50. It is determined that the engine 22 should be started when the determination threshold Pj corresponding to the storage ratio SOC is reached or more. However, instead of the vehicle required power Pv, the accelerator opening Acc, the required torque Tr *, and the driving When a parameter such as power Pdrv is within the range of two thresholds, and when the integrated value of the parameter obtained by subtracting the lower threshold reaches a threshold for determination according to the vehicle speed V or the storage ratio SOC of the battery 50 It may be determined that the engine 22 should be started.

  In the hybrid vehicle 20 of the embodiment, when the vehicle required power Pv is greater than or equal to the threshold value Pref1 and less than the threshold value Pref2, the excess integrated value Pov that is the integrated value of the vehicle required power Pv minus the threshold value Pref1 is the vehicle speed V or the battery 50. It is determined that the engine 22 should be started when the determination threshold value Pj corresponding to the storage ratio SOC is reached, but instead of the excess integrated value Pov, the vehicle required power Pv has reached the threshold value Pref1 or more. It may be determined that the engine 22 should be started when the elapsed time reaches a determination threshold value or more according to the vehicle speed V or the storage ratio SOC of the battery 50.

  In the hybrid vehicle 20 of the embodiment, the power from the motor MG2 is output to the drive shaft 36 connected to the drive wheels 63a and 63b. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. The power from MG2 may be output to an axle (an axle connected to wheels 39a and 39b in FIG. 6) different from an axle to which drive shaft 36 is connected (an axle to which drive wheels 38a and 38b are connected). .

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 via the planetary gear 30 and the power from the motor MG2 is output to the drive shaft 36. However, the hybrid of the modified example of FIG. As exemplified in the automobile 220, the motor MG is attached to the drive shaft connected to the drive wheels 38a and 38b via the transmission 230, and the engine 22 is connected to the rotation shaft of the motor MG via the clutch 229. The power from the engine 22 may be output to the drive shaft via the rotation shaft of the motor MG and the transmission 230, and the power from the motor MG may be output to the drive shaft via the transmission 230. Further, as illustrated in the hybrid vehicle 320 of the modification of FIG. 8, the power from the engine 22 is output to the axle connected to the drive wheels 38a and 38b via the transmission 330 and the power from the motor MG is driven. It is good also as what outputs to the axle different from the axle connected to wheel 38a, 38b (the axle connected to wheel 39a, 39b in FIG. 8).

  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 “engine”, the motor MG2 corresponds to the “motor”, the battery 50 corresponds to the “battery”, and the HVECU 70 that executes the engine start determination processing routine of FIG. It corresponds to “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, 220, 320 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 383a, 38b drive wheel, 39a, 39b wheel, 40 electronic control unit for motor (motor ECU), 41, 42 inverter, 50 battery, 70 electronic control unit for hybrid, 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, 229 clutch, 230, 330 transmission, MG, MG1, MG2 motor.

Claims (6)

A hybrid vehicle equipped with an engine, a motor, and a battery capable of exchanging electric power with the motor,
When a request parameter related to a travel request by a driver is greater than or equal to a predetermined value during motor travel that travels with power from the motor while the engine is stopped, a threshold value for determination is set to increase as the vehicle speed increases. A start determination means for determining start of the engine when an integration parameter that is integrated when the required parameter is equal to or greater than the predetermined value reaches a threshold for determination;
A hybrid vehicle comprising: The hybrid vehicle according to claim 1,
The integration parameter is a parameter that is added when the required parameter is greater than or equal to the predetermined value, and subtracted within a range of up to a value of 0 when the required parameter is less than the predetermined value.
Hybrid car. A hybrid vehicle according to claim 1 or 2,
The start determination unit is a unit that sets the determination threshold in such a manner that the larger the power storage ratio that is the ratio of the power storage capacity to the total capacity of the battery, the larger the power storage ratio.
Hybrid car. A hybrid vehicle according to any one of claims 1 to 3,
The start determination unit is a unit that sets a value of 0 to the determination threshold when the temperature of the battery is equal to or higher than a predetermined temperature.
Hybrid car. A hybrid vehicle according to any one of claims 1 to 4,
The start determination means determines the start of the engine even when the integrated parameter is less than the determination threshold when the required parameter reaches a second predetermined value greater than the predetermined value while the motor is running. Is,
Hybrid car. A hybrid vehicle according to any one of claims 1 to 5,
The required parameter is a vehicle required power based on a power required for traveling,
The integration parameter is an integration amount obtained by integrating the difference between the vehicle required power and the predetermined value.
Hybrid car.

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