JP2013230705A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more certainly start a system on a hybrid vehicle.SOLUTION: When it is determined that an engine is a high temperature state, and a battery voltage VB2 of a low voltage battery is less than prescribed voltage VBref (step S110 and S130), and when the battery voltage VB 2 cannot use the electric power from the high voltage battery, converter output improvement control to control a DC/DC converter is executed, so that relief valve open/close control is performed and the voltage becomes a prescribed voltage VBref that is the lower limit of the voltage range that allows system starting afterwards (step S140). As a result, when a system is turned off, relief valve open/close control can be completely executed, and when booting up the system by ignition on, the system startup can be more certainly performed.

Description

  The present invention relates to a hybrid vehicle, and more specifically, an engine capable of outputting driving power, an electric motor capable of inputting / outputting driving power, a first battery capable of exchanging electric power with the electric motor, A system main relay for connecting to and disconnecting from one battery, a second battery, an operating device that receives power from a second battery voltage system to which the second battery is connected, an electric motor, and a first battery The voltage of the second battery voltage system is adjusted by being connected to the first battery voltage system and the second battery voltage system connected to one battery, and the electric power between the first battery voltage system and the second battery voltage system is adjusted. The system main relay is controlled so that the step-up converter for exchanging and the motor and the first battery are connected when the ignition is turned on. Deployment is a hybrid vehicle and a control means for controlling the system main relay so that the connection between the electric motor and the first battery is released when being turned off.

  Conventionally, as this type of hybrid vehicle, an engine, a motor, an HV battery connected to the motor via a system main relay and supplying a high voltage to the motor, an auxiliary battery supplying electric power to the auxiliary machine, A converter that converts a high-voltage DC voltage of the HV battery into a low-voltage DC voltage and supplies it to the auxiliary battery and each ECU that operates with electric power from the auxiliary battery to control the engine and the motor, and turns off the system It has been proposed that the system main relay is sometimes turned off and the system main relay is turned on when the system is turned on (see, for example, Patent Document 1). In this hybrid vehicle, when a system startup request is made when the system is off, if the auxiliary battery voltage is lower than the minimum reference voltage, which is the voltage at which each ECU can normally start, the system main By starting the system after the converter is controlled so that the auxiliary battery is charged with the electric power from the HV battery by turning on the relay, each ECU is normally operated to start the system.

JP 2001-320807 A

  In the hybrid vehicle described above, if the voltage of the auxiliary battery becomes lower than the voltage at which the system main relay can be normally driven when the system is turned off, the system main relay cannot be turned on. If the system main relay cannot be turned on, the auxiliary battery cannot be charged using the power from the HV battery, and the system cannot be started.

  The main object of the hybrid vehicle of the present invention is to start the system more reliably.

  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
An engine capable of outputting power for traveling, an electric motor capable of outputting power for traveling, a first battery capable of exchanging electric power with the motor, and connection and connection between the electric motor and the first battery Connected to the system main relay, the second battery, the operating device that receives power from the second battery voltage system to which the second battery is connected, the motor, and the first battery. The first battery voltage system and the second battery voltage system are connected to adjust the voltage of the second battery voltage system, and power is exchanged between the first battery voltage system and the second battery voltage system. The system main relay is controlled so that the converter to be connected and the electric motor and the first battery are connected when the ignition is on. Nisshon is a hybrid vehicle and a control means for controlling the system main relay so the connection is released between the first battery and the electric motor when being turned off,
When the ignition is on, the control means satisfies an off-time operation condition in which an off-time operation control is performed to operate the operation device with the power of the second battery when the ignition is off, and the voltage of the second battery Is lower than a second battery voltage drop determination voltage that is predetermined as a voltage capable of starting the system even when the off-time operation control is executed while the ignition is turned off, the voltage of the second battery is Means for controlling the converter to be the second battery voltage drop determination voltage;
This is the gist.

  In the hybrid vehicle of the present invention, the system main relay is controlled so that the electric motor and the first battery are connected when the ignition is on, and between the electric motor and the first battery when the ignition is off. The system main relay is controlled so as to be disconnected. When the ignition is turned on, an off-time operation condition for executing an off-time operation control for operating the operating device with the power of the second battery when the ignition is off is satisfied, and the voltage of the second battery is turned off. Even if the off-time operation control is executed, the voltage of the second battery becomes the second battery voltage drop determination voltage when the voltage is lower than the second battery voltage drop determination voltage that is predetermined as a voltage that can start the system. Control the converter to As a result, the ignition is turned off while the second battery is set to a voltage equal to or higher than the second battery voltage drop determination voltage, and the off-time operation control can be executed while the ignition is turned off. The system can be started more reliably when turned on.

  In such a hybrid vehicle of the present invention, the engine includes a fuel tank, a circulation passage that circulates fuel from the fuel tank to a fuel injection valve of the engine, and a return valve that is provided in the circulation passage and can be opened and closed. The operation device is the return valve, and the off-time operation control controls the return valve so that the return valve is opened and closed while the ignition is turned off. It is also possible to assume that the control is to In this way, the off-time operation control can be executed more reliably when the ignition is turned off, and the system can be started more reliably when the ignition is turned on. In addition, by executing such off-time work control, when the system is turned off with the pressure in the circulation flow path increased, the pressure in the circulation flow path is lowered to suppress the back flow of fuel to the fuel tank. Then, the startability of the engine when the ignition is turned on and the engine is started can be improved. In this case, the off-time operation condition is a condition that the cooling water temperature of the engine is equal to or higher than a predetermined water temperature, a condition that the temperature of lubricating oil for lubricating the engine is equal to or higher than a predetermined oil temperature, Conditions under which the outside air temperature is equal to or higher than a predetermined air temperature, conditions under which the water temperature sensor for detecting the cooling water temperature of the engine is normal, and conditions under which the air intake temperature sensor for detecting the intake air temperature of the engine is normal And at least one of the conditions.

  Further, in the hybrid vehicle of the present invention, a generator, a planetary gear mechanism in which three rotating elements are connected to three axes of a driving shaft connected to an axle, an output shaft of the engine, and a rotating shaft of the generator; The motor has a rotating shaft connected to the drive shaft, and the high-voltage battery can exchange power with the motor and the generator.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22 and a fuel supply device 60. FIG. It is a flowchart which shows an example of the control routine at the time of ignition ON performed by HVECU70 of an Example. It is a flowchart which shows an example of the control routine at the time of the ignition off performed by HVECU70 of an Example. 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 one embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of an engine 22 and a fuel supply device 60. As shown in the figure, the hybrid vehicle 20 of the embodiment uses an engine 22 that outputs power using gasoline or light oil as a fuel, a fuel supply device 60 that supplies fuel from a fuel tank 58 to the engine 22, and lubricating oil. A carrier is connected to a lubrication device 90 for lubricating the engine 22, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 for driving and controlling the engine 22, and a crankshaft 26 of the engine 22, and driving wheels 38a and 38b. A planetary gear 30 in which a ring gear is connected to a drive shaft 36 coupled to a differential gear 37, a motor MG1 configured as, for example, a synchronous generator motor and having a rotor connected to a sun gear of the planetary gear 30, and a synchronous generator motor, for example. The rotor is connected to the drive shaft 36 Motor MG2, motor inverters MG1 and MG2, inverters 41 and 42 for driving motors, and a motor electronic control unit for driving and controlling motors MG1 and MG2 by switching control of switching elements (not shown) of inverters 41 and 42 ( (Hereinafter referred to as “motor ECU”) 40 and a high voltage battery configured as a lithium ion secondary battery having a rated voltage of, for example, 200 V, and exchanges power with motors MG1 and MG2 via system main relay 56 and inverters 41 and 42. 50, a battery electronic control unit (hereinafter referred to as a battery ECU) 52 for managing the high voltage battery 50, and a power line (hereinafter referred to as a low voltage system power line) 54b to which each ECU, auxiliary machine 57a, and the like are connected. Connected lead storage with a rated voltage of 12V, for example The low-voltage system power line 54b is obtained by stepping down power from a low-voltage battery 57b configured as a pond, and a power line (hereinafter referred to as a high-voltage system power line) 54a connecting the inverters 41 and 42 and the high-voltage battery 50. And a hybrid electronic control unit (hereinafter referred to as HVECU) 70 for controlling the entire vehicle.

  As shown in FIG. 2, the engine 22 includes an in-cylinder fuel injection valve 125 that directly injects hydrocarbon-based fuel such as gasoline and light oil into a cylinder, and a port fuel injection valve 126 that injects fuel into an intake port. It is comprised as an internal combustion engine provided with these. The engine 22 is provided with these two types of fuel injection valves 125 and 126, so that the air cleaned by the air cleaner 122 is sucked through the throttle valve 124 and fuel is injected from the port fuel injection valve 126. The mixed air and fuel are mixed, and the mixture is sucked into the combustion chamber via the intake valve 128, and explosively burned by the electric spark from the spark plug 130. The reciprocating motion of the piston 132 pushed down by the energy is applied to the crankshaft. In the same manner as in the port injection drive mode for converting to 26 rotational motion, air is sucked into the combustion chamber, and fuel is injected from the in-cylinder fuel injection valve 125 after the intake stroke or the compression stroke is reached. The crankshaft 26 is rotated by an electric spark caused by explosion. In-cylinder injection drive mode for obtaining movement, and when injecting air into the combustion chamber, fuel is injected from the port fuel injection valve 126 and fuel is injected from the in-cylinder fuel injection valve 125 in the intake stroke and compression stroke, and the crankshaft Operation control is performed in any one of the common injection drive mode for obtaining 26 rotational motions. These drive modes are switched based on the operation state of the engine 22, the operation state required for the engine 22, and the like. Exhaust gas from the engine 22 is discharged to the outside air through a purifier 134 having a three-way catalyst that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). .

  The fuel supply device 60 is configured as a device that supplies the fuel in the fuel tank 58 to the in-cylinder fuel injection valve 125 and the port fuel injection valve 126 of the engine 22, and the fuel in the fuel tank 58 is supplied to the port fuel. An electric fuel pump 62 that supplies the fuel pipe 63 to which the injection valve 126 is connected, and a high-pressure pump 64 that pressurizes the fuel in the fuel pipe 63 and supplies it to the delivery pipe 66 to which the in-cylinder fuel injection valve 125 is connected. And an electromagnetic valve provided in a relief pipe 68 connected to the delivery pipe 66 and the fuel tank 58 and capable of reducing the pressure of the pressurized fuel in the delivery pipe 66 by a differential pressure from the atmospheric pressure. A relief valve 67. The high-pressure pump 64 is a pump that is driven by the power from the engine 22 to pressurize the fuel in the fuel pipe 63. The high-pressure pump 64 is connected to the suction port and opens and closes when the fuel is pressurized. A check valve 64b which is connected to prevent the backflow of fuel and holds the pressure of fuel in the delivery pipe 66 (fuel pressure). As a result, the high pressure pump 64 draws in fuel from the fuel pump 62 when the electromagnetic valve 64a is opened during operation of the engine 22, and operates with power from the engine 22 when the electromagnetic valve 64a is closed. The fuel supplied to the delivery pipe 66 is pressurized by intermittently sending the fuel compressed by the plunger (not shown) to the delivery pipe 66 through the check valve 64b. Note that the relief valve 67 is operated by electric power from the low voltage battery 57b.

  Lubricating device 90 includes an oil pan 92 provided in the lower part of the vehicle, and an oil pump 94 attached to crankshaft 26 of engine 22. The oil pump 94 is driven by the engine 22 and supplies the lubricating oil stored in the oil pan 92 to the engine 22. The lubricating oil supplied to the engine 22 returns to the oil pan 92 via each part of the engine 22.

  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 state of the engine 22, for example, a crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 26, and a water temperature that detects the temperature of cooling water in the engine 22. The cooling water temperature Tw from the sensor 142, the in-cylinder pressure Pin from the pressure sensor 143 installed in the combustion chamber, the intake camshaft for opening and closing the intake valve 128 for intake and exhaust to the combustion chamber, and the exhaust camshaft for opening and closing the exhaust valve The cam position θca from the cam position sensor 144 that detects the rotational position, the throttle opening TH from the throttle valve position sensor 146 that detects the position of the throttle valve 124, and the suction from the air flow meter 148 attached to the intake pipe The air volume Qa, the intake air temperature Ta from the temperature sensor 149 attached to the intake pipe, the catalyst temperature Tc from the temperature sensor attached to the purifier 134, the air-fuel ratio AF from the air-fuel ratio sensor 135a, and the oxygen sensor 135b From an oxygen signal O2, a knock signal Ks from a knock sensor that is attached to the cylinder block and detects vibration caused by the occurrence of knocking, and a fuel pressure sensor 69 that detects the pressure of fuel in the delivery pipe 66 of the fuel supply device 60 The fuel pressure Pf, the oil temperature Toil from the oil temperature sensor 96 that detects the temperature of the lubricating oil of the lubricating device 90, and the like are input via the input port. Further, the engine ECU 24 determines various control signals for driving the engine 22, such as a drive signal to the cylinder fuel injection valve 125, a drive signal to the port fuel injection valve 126, and the position of the throttle valve 124. Drive signal to throttle motor 136 to be adjusted, control signal to ignition coil 138 integrated with igniter, control signal to variable valve timing mechanism 150 capable of changing opening / closing timing of intake valve 128, drive to fuel pump 62 A signal, a drive signal to the electromagnetic valve 64a of the high-pressure pump, a drive signal to the relief valve 67, and the like are output via the output port. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and outputs data related to the operation state of the engine 22 as necessary. The engine ECU 24 calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on the crank position from the crank position sensor 140, and the intake air amount Qa from the air flow meter 148 and the rotational speed of the engine 22. Based on Ne, the volume efficiency (ratio of the volume of air actually sucked in one cycle to the stroke volume per cycle of the engine 22) KL is calculated, or the magnitude or waveform of the knock signal Ks from the knock sensor is calculated. Based on this, a knock intensity Kr indicating the level of occurrence of knocking is calculated. Further, the engine ECU 24 determines whether or not the water temperature sensor 142 is normal based on the cooling water temperature Tw from the water temperature sensor 142 and whether or not the temperature sensor 149 is normal based on the intake air temperature Ta from the temperature sensor 149. Execute such a determination. Whether or not the water temperature sensor 142 and the temperature sensor 149 are normal is determined by, for example, the water temperature even though it is estimated that the engine 22 has been operated for a considerable time and the engine 22 is at a relatively high temperature. Assume that the water temperature sensor 142 and the temperature sensor 149 are abnormal when the cooling water temperature Tw from the sensor 142 and the intake air temperature Ta from the temperature sensor 149 are low.

  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 rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and not shown. A phase current applied to the motors MG1 and MG2 detected by the current sensor is input via the input port, and the motor ECU 40 outputs a switching control signal to switching elements (not shown) of the inverters 41 and 42. It is output through the 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 angular velocities ωm1, ωm2 and the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44. ing.

  The high voltage battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 is connected to a signal necessary for managing the high voltage battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the high voltage battery 50, and an output terminal of the high voltage battery 50. The charging / discharging current from a current sensor (not shown) attached to the high voltage system power line 54, the battery temperature Tb from the temperature sensor 51 attached to the high voltage battery 50, and the like are input. Data regarding the state of the voltage battery 50 is output to the hybrid electronic control unit 70 by communication. Further, the battery ECU 52 calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the high voltage battery 50, or calculates the remaining capacity (SOC) and the battery temperature. Based on Tb, input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the high voltage battery 50, are calculated. The input / output limits Win and Wout of the high voltage battery 50 are set to basic values of the input / output limits Win and Wout based on the battery temperature Tb, and are used for output limitation based on the remaining capacity (SOC) of the high voltage battery 50. The correction coefficient and the input restriction correction coefficient are set, and can be set by multiplying the basic values of the set input / output restrictions Win and Wout by the correction coefficient.

  The HVECU 70 is configured as a microprocessor centered on the CPU 72, and includes, in addition to the CPU 72, a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, an input / output port and a communication port (not shown). . 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, brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, the outside air temperature Ta from the outside air temperature sensor 89, and the terminal of the low voltage battery 57b. The battery voltage VB or the like from the voltage sensor 57d is input through the input port. From the HVECU 70, a drive signal to the system main relay 56, a switching control signal to the DC / DC converter 57c, and the like are output via an output 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 36 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 operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque Tr * 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 the power corresponding to the required power 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. Torque conversion operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that torque is converted by the MG1 and the motor MG2 and output to the drive shaft 36, and the sum of the required power and the power required for charging and discharging the high voltage battery 50 The engine 22 is operated and controlled so that the power suitable for the engine 22 is output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the high-voltage battery 50 is transmitted to the planetary gear 30, the motor MG1, and the motor. The required power is applied to the drive shaft 36 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that the motor MG1 is powered, motor operation 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, etc. There is. 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 required power is output to the drive shaft 36 with the operation of the engine 22. Since there is no substantial difference in control, hereinafter, both can be considered as the engine operation mode.

  In the DC / DC converter 57c, basically, a transistor (not shown) is subjected to switching control so that the voltage VB2 of the low voltage battery 57b is within a predetermined voltage range as a voltage that can sufficiently operate the auxiliary device 59. The Hereinafter, such control is referred to as converter normal control.

  The system main relay 56 is turned on when the ignition is turned on by the ignition signal from the ignition switch 80, and the system main relay 56 is turned off when the vehicle is stopped by the ignition signal from the ignition switch 80. To be controlled. As a result, when the ignition is on, power can be supplied from the high voltage battery 50 to the motors MG1 and MG2, and when the ignition is off, the power supply from the high voltage battery 50 to the motors MG1 and MG2 is cut off.

  Next, it is estimated that the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when the engine 22 is estimated to be hot when the ignition is on, and the engine 22 is hot. The operation when the ignition is turned off in the state of being performed will be described. First, the operation when the ignition is on will be described. FIG. 3 is a flowchart illustrating an example of an ignition-on time control routine executed by the HVECU 70 of the embodiment. The ignition-on-time control routine shown in FIG. 3 is performed at predetermined time intervals (for example, several msec), such as when the operation of the engine 22 is stopped in the ignition-on state, such as when the accelerator pedal 83 is released during traveling. Every time).

  When the ignition on-time control routine is executed, the HVECU 70 first executes a process of inputting the coolant temperature Tw, the oil temperature Toil, the intake air temperature Ta, the outside air temperature Tat from the outside air temperature sensor 89, etc. (step) S100). Here, the cooling water temperature Tw, the oil temperature Toil, and the intake air temperature Ta are detected by the water temperature sensor 142, the oil temperature sensor 96, and the temperature sensor 149, respectively, and are input via the engine ECU 24.

  Subsequently, it is determined whether or not the engine 22 is in a high temperature state (step S110). In the process of step S110, the condition that the cooling water temperature Tw is equal to or higher than the predetermined water temperature Twref, the condition that the oil temperature Toil is equal to or higher than the predetermined oil temperature Toref, the condition that the outside air temperature Tat is equal to or higher than the predetermined temperature Tatref, and the intake air temperature Ta are There are six conditions: a condition that is equal to or higher than a predetermined intake air temperature Taref, a condition that the engine ECU 24 determines that the water temperature sensor 142 is normal, and a condition that the engine ECU 24 determines that the oil temperature sensor 96 is normal. When all the conditions are satisfied, it is determined that the engine 22 is in a high temperature state. Here, the predetermined water temperature Twref, the predetermined oil temperature Toref, the predetermined air temperature Taref, and the predetermined intake air temperature Taref are generated by the vapor generated in the delivery pipe 66 after the operation of the engine 22 is stopped, and fuel from the high pressure pump 64 toward the fuel tank 58. The lower limit of the temperature range in which the startability of the next engine 22 is estimated to decrease due to the reverse flow of the engine 22 is used. For example, the predetermined oil temperature Toref is 60 ° C, 65 ° C, 70 ° C, etc. The predetermined air temperature Taref is 25 ° C, 28 ° C, 30 ° C, such as 105 ° C, 110 ° C, 115 ° C, and the predetermined intake air temperature Taref is 25 ° C, 28 ° C, 30 ° C, etc.

  The determination in step S110 is based on the following reason. If the operation is stopped when the engine 22 is at a relatively high temperature, vapor is generated in the delivery pipe 66 after the operation of the engine 22 is stopped, and the pressure in the delivery pipe 66 rises. The startability of the next engine 22 may deteriorate due to the reverse flow of fuel. In order to suppress such deterioration of the startability of the engine 22, as will be described later, when the engine 22 is at a relatively high temperature, the relief valve 67 is opened and closed when the ignition is turned off to lower the pressure in the delivery pipe 66. Relief valve opening / closing control is executed. The process of step S110 is a process of determining whether or not it is estimated that such relief valve opening / closing control is executed.

  When the engine 22 is not in a high temperature state, converter normal control is executed (step S120), and this routine is terminated. By such processing, the voltage VB2 of the low voltage battery 57b can be made a voltage that can sufficiently operate the auxiliary machine 59.

  When the engine 22 is in a high temperature state, it is subsequently determined whether or not the battery voltage VB2 of the low voltage battery 57b is equal to or higher than a predetermined voltage VBref (step S130). Here, the predetermined voltage VBref uses the lower limit of the voltage range in which the relief valve opening / closing control can be performed when the ignition is off and the power from the high voltage battery 50 cannot be used, or the system can be started thereafter. did. That is, the determination in step S110 is a process for determining whether or not the voltage is sufficient to start the system after the low voltage battery 57b is turned off and the relief valve opening / closing control is performed.

  When the battery voltage VB2 of the low voltage battery 57b is equal to or higher than the predetermined voltage VBref (step S130), it is determined that the battery voltage VB2 of the low voltage battery 57b is sufficiently high and the converter normal control is executed (step S120). When the battery voltage VB2 of the low voltage battery 57b is less than the predetermined voltage VBref (step S100), the converter output up control for controlling the DC / DC converter 57c so that the voltage of the low voltage battery 57b becomes the predetermined voltage VBref Is executed (step S130). By such processing, when the engine 22 is in a high temperature state, the battery voltage of the low voltage battery 57b can be made equal to or higher than the predetermined voltage VBref.

  Subsequently, an operation at the time of ignition off when it is determined in the process of step S110 that the engine 22 is in a high temperature state will be described. FIG. 4 is a flowchart illustrating an example of an ignition-off time control routine executed by the HVECU 70 of the embodiment. This routine is executed when it is determined in step S110 that the engine 22 is in a high temperature state, and then the ignition is switched from ignition on to ignition off by the ignition signal from the ignition switch 80.

  When the ignition-off time control routine is executed, the HVECU 70 transmits a drive signal for the relief valve 67 to the engine ECU 24 so that the relief valve opening / closing control for opening and closing the relief valve 67 and reducing the pressure is executed Nref a predetermined number of times (step) S200, S210), this routine is finished. The engine ECU 24 that has received the drive signal for the relief valve 67 controls the relief valve 67 so that the relief valve 67 opens and closes Nref a predetermined number of times. Here, the predetermined number of times Nref is a predetermined number of times of opening and closing the relief valve 67 that can lower the pressure in the delivery pipe 66 to such an extent that the fuel does not flow backward from the high pressure pump 64 toward the fuel tank 58. It was supposed to be. By such processing, the pressure in the delivery pipe 66 can be reduced, and the back flow of fuel can be suppressed. At this time, since the battery voltage VB2 of the low voltage battery 57b is equal to or higher than the predetermined voltage VBref by the ignition ON control routine illustrated in FIG. 3, the relief valve opening / closing control can be sufficiently executed. Further, the battery voltage VB2 of the low voltage battery 57b is lowered by the relief valve opening / closing control in this way. However, since the battery voltage VB2 of the low voltage battery 57b is equal to or higher than the predetermined voltage VBref before the system is turned off, the low voltage battery 57b. The battery voltage VB2 is a voltage that can perform various processes for starting the system even when the ignition is subsequently turned on to start the system, for example, a process for operating each ECU or a process for turning on the system main relay 56. Is secured. Therefore, the system can be started more reliably.

  According to the hybrid vehicle 20 of the embodiment described above, the converter output up control is executed when the battery voltage VB2 of the low voltage battery 57b is less than the predetermined voltage VBref when it is determined that the engine 22 is in a high temperature state. As a result, when the system is subsequently turned off, the relief valve opening / closing control can be sufficiently performed, and the system can be more reliably started when the ignition is turned on to start the system.

  In the hybrid vehicle 20 of the embodiment, in the process of step S110, the condition that the cooling water temperature Tw is equal to or higher than the predetermined water temperature Twref, the condition that the oil temperature Toil is equal to or higher than the predetermined oil temperature Toref, and the outside temperature Tat is equal to or higher than the predetermined temperature Tatref. There are certain conditions, conditions where the intake air temperature Ta is equal to or higher than the predetermined intake air temperature Taref, conditions where the engine ECU 24 determines that the water temperature sensor 142 is normal, and the engine ECU 24 determines that the oil temperature sensor 96 is normal. However, since it is sufficient to include at least one of these conditions, for example, the cooling water temperature Tw is equal to or higher than the predetermined water temperature Twref. And the condition that the oil temperature Toil is equal to or higher than the predetermined oil temperature Toref and the outside temperature Tat is the predetermined temperature T At least one of a condition that is equal to or higher than tref and a condition that the intake air temperature Ta is equal to or higher than the predetermined intake air temperature Taref, a condition that the engine ECU 24 determines that the water temperature sensor 142 is normal, and an oil temperature sensor 96 that is determined by the engine ECU 24 When at least one of the conditions determined to be normal is satisfied, the engine 22 may be determined to be in a high temperature state, or the condition that the cooling water temperature Tw is equal to or higher than a predetermined water temperature Twref, It may be determined that the engine 22 is in a high temperature state when the condition that the water temperature sensor 142 is determined to be normal by the engine ECU 24 is satisfied. Further, the condition in which the water temperature sensor 142 is determined to be normal by the engine ECU 24 and the condition in which the oil temperature sensor 96 is determined to be normal by the engine ECU 24 may not be considered.

  In the hybrid vehicle 20 of the embodiment, when the ignition is turned on, it is determined that the engine 22 is in a high temperature state in the process of step S110 of the ignition on-time control routine illustrated in FIG. 3, and illustrated in FIG. The relief valve opening / closing control is executed when the ignition is turned off in the process of step S200 of the ignition off control routine. However, in the process of step S200, it is executed when another ignition is turned off instead of the relief valve opening / closing control. As the control is executed, in place of the process of determining that the engine 22 is in the high temperature state in the process of step S110, another control that is executed instead of the relief valve opening / closing control after the ignition is turned off is executed. The condition may be satisfied.

  In the hybrid vehicle 20 of the embodiment, the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. 5, the drive shaft 36 transmits the power from the motor MG2. It may be connected to an axle (an axle connected to the wheels 39a and 39b in FIG. 5) different from the connected axle (the axle to which the 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 connected to the drive wheels 38a and 38b via the planetary gear 30, but is exemplified in the hybrid vehicle 220 of the modification of FIG. As described above, the inner rotor 232 connected to the crankshaft of the engine 22 and the outer rotor 234 connected to the drive shaft 36 that outputs power to the drive wheels 38a and 38b have a part of the power from the engine 22. A counter-rotor motor 230 that transmits power to the drive shaft 36 and converts remaining power into electric power may be provided.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 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 36. However, as illustrated in the hybrid vehicle 320 of the modified example of FIG. 7, the motor MG is attached to the drive shaft 36 connected to the drive wheels 38a and 38b via the transmission 330, and the clutch 329 is attached to the rotation shaft of the motor MG. The power from the engine 22 is output to the drive shaft 36 via the rotation shaft of the motor MG and the transmission 330, and the power from the motor MG is output 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 modification of FIG. 8, the power from the engine 22 is output to the drive shaft 36 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. 8). In other words, any type of hybrid vehicle may be used as long as it includes an engine and an electric motor that inputs and outputs driving power.

  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 “electric motor”, the high voltage battery 50 corresponds to the “first battery”, and the system main relay 56 corresponds to the “system main relay”. The low voltage battery 57b corresponds to the “second battery”, the relief valve 67 corresponds to the “actuating device”, the DC / DC converter 57c corresponds to the “converter”, and the ignition-on control routine of FIG. The HVECU 70 to be executed corresponds to “control means”.

  Here, the “engine” is not limited to the engine 22 that outputs power using gasoline or light oil as a fuel, but any type of engine that can output power for traveling, such as a hydrogen engine. It does not matter. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor as long as it can input and output driving power, such as an induction motor. . The “first battery” is not limited to the high voltage battery 50 configured as a lithium ion secondary battery, and exchanges electric power with an electric motor such as a nickel hydride secondary battery, a nickel cadmium secondary battery, or a lead storage battery. Any type of battery may be used as long as it is possible. The “system main relay” is not limited to the system main relay 56, and any system can be used as long as the connection between the electric motor and the first battery and the disconnection are performed. The “second battery” is not limited to the low voltage battery 57b configured as a lead storage battery, and may be a nickel hydride secondary battery, a nickel cadmium secondary battery, a lithium ion secondary battery, or the like. . The “actuating device” is not limited to the relief valve 67 and may be any device that operates by receiving power from the second battery voltage system to which the second battery is connected. The “converter” is not limited to the DC / DC converter 57c, but is connected to the first battery voltage system and the second battery voltage system connected to the electric motor and the first battery, and is connected to the second battery voltage system. As long as the voltage is adjusted to be equal to or higher than the voltage of the first battery voltage system and power is exchanged between the first battery voltage system and the second battery voltage system, any voltage may be used. The “control means” is not limited to the HVECU which is a single electronic control unit, and may be configured by combining a plurality of electronic control units. As the “control means”, the system main relay 56 is controlled so that the motor MG2 and the high voltage battery 50 are connected when the ignition is on, and between the motor MG2 and the high voltage battery 50 when the ignition is off. When the system main relay 56 is controlled so as to be disconnected or the ignition is on, the engine 22 is in a high temperature state, and the battery voltage VB2 of the low voltage battery 57b is less than the predetermined voltage VBref, the low voltage battery 57b The system main relay is not limited to the one that controls the DC / DC converter 57c so that the voltage VB becomes the predetermined voltage VBref, and the motor and the first battery are connected when the ignition is turned on. Control and turn off the ignition When the system main relay is controlled so that the connection between the electric motor and the first battery is released, or when the ignition is turned on, when the ignition is off, the operation device is operated with the power of the second battery. When the off-time operation condition for executing the operation control is satisfied and the voltage of the second battery is lower than a predetermined second battery voltage drop determination voltage, the voltage of the second battery is higher than the second battery voltage drop determination voltage. Any converter may be used as long as it controls the converter so that the voltage becomes a predetermined determination voltage for completion of charging the second battery voltage.

  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, 420 Hybrid vehicle, 22 engine, 24 electronic control unit for engine (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 39a, 39b Wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 High voltage battery, 51c Temperature sensor, 52 Battery electronic control unit (battery ECU), 54a High voltage system Power line, 54b Low voltage system power line, 56 System main relay, 57a Auxiliary machine, 57b Low voltage battery, 57c DC / DC converter, 58 Fuel tank, 60 Fuel supply device, 62 Fuel pump, 63 Fuel pipe 64 High pressure pump, 64a Solenoid valve, 64b Check valve, 66 Delivery pipe, 67 Relief valve, 68 Relief pipe, 69 Fuel pressure sensor, 70 Hybrid electronic control unit (HVECU), 72 CPU, 74 ROM, 76 RAM, 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, 90 Lubricator, 92 Oil pan, 94 Oil pump, 96 Oil temperature Sensor, 122 Air cleaner, 124 Throttle valve, 125 In-cylinder fuel injection valve, 126 port fuel injection valve, 128 Intake valve, 130 Spark plug, 32 piston, 134 purification device, 135a air-fuel ratio sensor, 135b oxygen sensor, 136, throttle motor, 138 ignition coil, 140 crank position sensor, 142 water temperature sensor, 143 pressure sensor, 144 cam position sensor, 146 throttle valve position sensor, 148 Air flow meter, 149 temperature sensor, 150 variable valve timing mechanism, 230 pair rotor motor, 232 inner rotor, 234 outer rotor, 329 clutch, 330, 430 transmission, MG, MG1, MG2 motor.

Claims (4)

An engine capable of outputting power for traveling, a motor capable of inputting / outputting power for traveling, a first battery capable of exchanging electric power with the motor, connection between the motor and the first battery, and Connected to the system main relay for releasing the connection, the second battery, the operating device that receives power from the second battery voltage system to which the second battery is connected, the electric motor, and the first battery. The first battery voltage system and the second battery voltage system are connected to adjust the voltage of the second battery voltage system to be higher than the voltage of the first battery voltage system, and the first battery voltage system and the second battery voltage system. The converter that exchanges power with the battery voltage system and the motor and the first battery are connected when the ignition is on. A hybrid vehicle comprising: control means for controlling the system main relay to control the system main relay so that the connection between the electric motor and the first battery is released when the ignition is off. ,
When the ignition is on, the control means satisfies an off-time operation condition in which an off-time operation control is performed to operate the operation device with the power of the second battery when the ignition is off, and the voltage of the second battery Is lower than a second battery voltage drop determination voltage that is predetermined as a voltage capable of starting the system even when the off-time operation control is executed while the ignition is turned off, the voltage of the second battery is Means for controlling the converter to be the second battery voltage drop determination voltage;
Hybrid car. The hybrid vehicle according to claim 1,
The engine includes a fuel supply device that includes a fuel tank, a circulation passage that circulates fuel from the fuel tank to a fuel injection valve of the engine, and a return valve that is provided in the circulation passage and can be opened and closed. The actuating device is the return valve, and the off-time operation control is control for controlling the return valve so that the return valve is opened and closed while the ignition is turned off. A hybrid vehicle according to claim 2,
The off-time operation condition includes a condition that a cooling water temperature of the engine is equal to or higher than a predetermined water temperature, a temperature of lubricating oil for lubricating the engine is equal to or higher than a predetermined oil temperature, and an outside air temperature is predetermined. At least one of a condition that is equal to or higher than a predetermined air temperature, a condition that a water temperature sensor for detecting the cooling water temperature of the engine is normal, and a condition that the intake air temperature sensor that detects the intake air temperature of the engine is normal Including hybrid vehicles. A hybrid vehicle according to any one of claims 1 to 3, wherein
A generator,
A planetary gear mechanism in which three rotating elements are connected to three axes of a driving shaft connected to an axle, an output shaft of the engine, and a rotating shaft of the generator;
With
The electric motor has a rotating shaft connected to the driving shaft,
The high-voltage battery is capable of exchanging electric power with the electric motor and the generator.

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