JP2013043605A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate start of a variable valve timing mechanism when an engine is driven.SOLUTION: When an oil temperature Toil of a lubrication system for the engine is a predetermined temperature threshold Tref or more, the engine, the variable valve timing mechanism and two motors are controlled so that the engine is operated by a driving point based on a required power Pe* corresponding to a required torque Tr* and an operation line for high oil temperature where the engine rotation tends to be higher than a fuel optimal operation line, and the vehicle travels with the required torque Tr*. Thus, even when the hydraulic pressure is not likely to increase by rotary drive of a mechanical pump since the oil viscosity is high due to high temperature when the oil temperature Toil is the temperature threshold Tref or higher, the engine rotation can be increased and locking by a lock pin in the variable valve timing mechanism is easily released. As a result, the variable valve timing mechanism can be easily started when the engine is driven.

Description

  The present invention relates to a hybrid vehicle, and more particularly, an engine, a variable valve timing mechanism attached to the engine, a first motor, a drive shaft connected to an axle, an output shaft of the engine, and a rotation shaft of the first motor. The present invention relates to a hybrid vehicle including a planetary gear in which three rotating elements are connected to the three shafts, a second motor connected to a drive shaft, and a battery.

  Conventionally, in this type of hybrid vehicle, the lock pin is removed from the locking hole by using the hydraulic pressure of the hydraulic oil from the engine and the oil pump that pumps the hydraulic oil as the crankshaft of the engine rotates. The variable valve timing mechanism that can change the valve timing of the intake valve from the most retarded timing, the first motor (MG1), the drive shaft connected to the drive wheels, the crankshaft of the engine, and the rotation of the first motor A planetary gear in which a ring gear, a carrier, and a sun gear are connected to three axes of the shaft, a second motor (MG2) connected to the drive shaft, and a battery that can exchange power with the first and second motors. When the engine is requested to start and the oil temperature is high, the viscosity of the oil is low and the oil pressure is high. In view of this, it has been proposed to start the engine by motoring it by setting the engine ignition start rotation speed to a higher rotation speed than when the oil temperature is not high (see, for example, Patent Document 1). ). In this hybrid vehicle, this ensures that the lock pin of the variable valve timing mechanism is securely removed from the locking hole even when the oil temperature of the hydraulic oil is high, and the valve timing of the intake valve is started after the engine starts. It can be changed smoothly.

JP 2007-153212 A

  In the above-described hybrid vehicle, considering the state in which the lock pin of the variable valve timing mechanism is inserted into the engaging hole during the operation of the engine after the engine is motored and started, the hydraulic oil in this state When the temperature is high, since the engine speed is low, there may be a case where sufficient hydraulic pressure to remove the lock pin from the locking hole cannot be secured.

  The main purpose of the hybrid vehicle of the present invention is to facilitate the operation of the variable valve timing mechanism when the engine is operated.

  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
Opening / closing timing of at least one of the intake valve and the exhaust valve of the engine by releasing the lock by the lock member using the pressure of hydraulic oil from the engine and a pump attached to the engine and driven by the rotation of the engine Variable valve timing mechanism, a first motor, a planetary gear 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 first motor A hybrid vehicle comprising: a second motor connected to the drive shaft; and a battery capable of exchanging electric power with the first motor and the second motor.
The engine is operated at an operation point based on a required power corresponding to a required driving force for traveling and an operation line for efficiency in which a relationship between the rotational speed and torque of the engine is predetermined in order to efficiently operate the engine. Control means for controlling the engine, the variable valve timing mechanism, the first motor, and the second motor so as to travel with the required driving force,
The control means is based on the required power and a high oil temperature operation line in which the engine speed tends to be higher than the efficiency operation line when the temperature of the hydraulic oil is equal to or higher than a predetermined temperature threshold. The engine is operated at an operating point and is controlled to travel with the required driving force.
It is characterized by that.

  In the hybrid vehicle of the present invention, the driving point based on the required power corresponding to the required driving force for traveling and the operation line for efficiency in which the relationship between the engine speed and the torque is predetermined in order to efficiently drive the engine. The engine, the variable valve timing mechanism, the first motor, and the second motor are controlled so that the engine is operated and travels with the required driving force. When the temperature of the hydraulic oil is equal to or higher than a predetermined temperature threshold, the engine is operated at an operating point based on the required power and the high oil temperature operation line in which the engine speed tends to be higher than the efficiency operation line. And control to run with the required driving force. Accordingly, it is possible to easily release the lock by the lock member of the variable valve timing mechanism when the temperature of the hydraulic oil is higher than the temperature threshold. As a result, the variable valve timing mechanism can be easily operated when the engine is operated. Here, the temperature threshold value may be a threshold value that is predetermined as a temperature that is high enough to cause a possibility that the lock by the lock member of the variable valve timing mechanism is not released.

  In such a hybrid vehicle of the present invention, the high oil temperature operation line is an operation line in which the engine speed tends to be higher than the efficiency operation line as the temperature of the hydraulic oil is higher than the temperature threshold. Can also be. In this way, when the temperature of the hydraulic oil is higher than the temperature threshold, it is easy to release the lock by the lock member of the variable valve timing mechanism, and a high oil temperature operation line that is different from the efficiency operation line is used. It is possible to more appropriately adjust the suppression of the decrease in energy efficiency due to the above. As a result, it is possible to achieve both the easy operation of the variable valve timing mechanism when the engine is operated and the suppression of the decrease in energy efficiency.

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 an external configuration diagram showing an external configuration of a variable valve timing mechanism 150. FIG. 2 is a configuration diagram showing an outline of a configuration of a variable valve timing mechanism 150. FIG. It is a block diagram which shows the outline of a structure of the lock pin 154. It is a flowchart which shows an example of the drive control routine performed by the electronic control unit for hybrids 70 of an Example. It is explanatory drawing which shows a mode that an example of the fuel consumption optimal operation line of the engine 22, and target rotational speed Ne * and target torque Te * are set. 4 is an explanatory diagram showing an example of an operation line for high oil temperature of an engine 22. FIG. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification.

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

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the drawing, the hybrid vehicle 20 of the embodiment includes an engine 22 that outputs power using gasoline or light oil as a fuel, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that controls the drive of the engine 22, an engine, and the like. A planetary gear 30 having a carrier connected to the crankshaft 26 and a ring gear connected to a drive shaft 36 connected to drive wheels 38a and 38b via a differential gear 37, and a rotor configured as a synchronous generator motor, for example. Motor MG1 connected to the sun gear of planetary gear 30, motor MG2 configured as, for example, a synchronous generator motor with the rotor connected to drive shaft 36, and motors MG1 and MG2 driven by switching of a plurality of switching elements (not shown). Inverters 41 and 4 And a motor electronic control unit (hereinafter referred to as a motor ECU) 40 that controls driving of the motors MG1 and MG2 by switching control of a plurality of switching elements of the inverters 41 and 42, and a lithium ion secondary battery, for example. A battery 50 that exchanges power with the motors MG1 and MG2 via the inverters 41 and 42, a battery electronic control unit (hereinafter referred to as a battery ECU) 52 that manages the battery 50, and the motors MG1 and MG2 and the inverters 41 and 42 A cooling device 60 for cooling and a hybrid electronic control unit (hereinafter referred to as HVECU) 70 for controlling the entire vehicle are provided.

  The engine 22 includes a variable valve timing mechanism 150 that can continuously change the opening / closing timing VT of the intake valve 128, as shown in the configuration diagrams of FIGS. The variable valve timing mechanism 150 is fixed to the intake camshaft 129 that opens and closes the intake valve 128 and the housing portion 152a fixed to the timing gear 164 connected to the crankshaft 26 via the timing chain 162, as shown in the figure. A vane-type VVT controller 152 including a vane portion 152b and an oil control valve 156 that applies hydraulic pressure to the advance chamber and the retard chamber of the VVT controller 152 are provided, and the advance of the VVT controller 152 is provided via the oil control valve 156. By adjusting the hydraulic pressure applied to the corner chamber and the retard chamber, the vane portion 152b is rotated relative to the housing portion 152a to continuously adjust the angle of the intake camshaft 129 at the opening / closing timing VT of the intake valve 128. To change. In the embodiment, the angle of the intake camshaft 129 at the opening / closing timing VT of the intake valve 128 at which power is efficiently output from the engine 22 is used as a reference angle, and the angle of the intake camshaft 129 is advanced from the reference angle. The engine 22 can be in an operating state in which high torque can be output, and by reducing the angle of the intake camshaft 129, the pressure fluctuation in the cylinder of the engine 22 is reduced to stop or start the operation of the engine 22. It is comprised so that it can be set as the driving | running state suitable for. It is to be noted that increasing the opening / closing timing VT of the intake valve 128, that is, advancing the angle of the intake camshaft 129 is referred to as “advancing”, and delaying the opening / closing timing VT of the intake valve 128, Reducing the angle of the intake camshaft 129 is referred to as “retarding”.

  Further, a lock pin 154 for fixing relative rotation between the housing portion 152a and the vane portion 152b is attached to the vane portion 152b of the VVT controller 152. FIG. 4 is a configuration diagram showing an outline of the configuration of the lock pin 154. As shown in the figure, the lock pin 154 includes a lock pin main body 154a and a spring 154b attached so that the lock pin main body 154a is biased toward the housing portion 152a, and the angle of the intake camshaft 129 is the most retarded angle. When it is positioned, the spring 154b is engaged with the groove 158 formed in the housing portion 152a by the spring force of the spring 154b to fix the vane portion 152b to the housing portion 152a (becomes locked). Further, the lock pin 154 can pull out the lock pin main body 154a fitted in the groove 158 by applying a hydraulic pressure that overcomes the spring force of the spring 154b via the oil passage 159 (can be released from the locked state). It has become. Note that the hydraulic pressure applied to the advance chamber and the retard chamber of the VVT controller 152, the hydraulic pressure for pulling out the lock pin main body 154a from the groove 158, that is, locking by the lock pin 154 at the most retarded position of the intake camshaft 129 is performed. The hydraulic pressure for releasing is based on a lubricating system oil (not shown) that lubricates the engine 22, and this oil is shown when the mechanical pump 170 driven by the rotation of the crankshaft 26 of the engine 22 is driven to rotate. Not supplied from oil pan.

  In the hybrid vehicle 20 of the embodiment, the variable valve timing mechanism 150 is described as being configured to be able to change the opening / closing timing of the intake valve 128. However, in addition to the intake valve 128, or in the intake valve 128, Instead, the opening / closing timing of the exhaust valve of the engine 22 may be changed. In this case, in the variable valve timing mechanism, the angle of the exhaust camshaft at the opening / closing timing of the exhaust valve at which power is efficiently output from the engine 22 is used as a reference angle, and the angle of the exhaust camshaft is set according to the operating state of the engine 22 The angle is retarded or advanced from the reference angle. The lock pin attached to the VVT controller on the exhaust camshaft side is engaged with the groove by the spring force when the angle of the exhaust camshaft is positioned at the most advanced angle, and the mechanical pump 170 is rotated. The locked state can be released by applying the hydraulic pressure of oil supplied by driving.

  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 pressure sensor mounted in the combustion chamber, the in-cylinder pressure Pin from the pressure sensor attached to the combustion chamber, the intake valve 128 for intake and exhaust to the combustion chamber, and the cam position sensor for detecting the rotational position of the camshaft for opening and closing the exhaust valve The cam position (for example, the cam position θca of the intake camshaft 129), the throttle position TP from the throttle valve position sensor that detects the throttle valve position, the intake air amount Qa from the air flow meter attached to the intake pipe, The intake air temperature Ta from the temperature sensor attached to the intake pipe, the air-fuel ratio AF from the air-fuel ratio sensor attached to the exhaust system, the oxygen signal O2 from the oxygen sensor also attached to the exhaust system, and the temperature of oil in the lubrication system The oil temperature Toil from the temperature sensor 151 that detects the engine is input via the input port, and various control signals for driving the engine 22, such as a drive signal to the fuel injection valve, Output port includes a drive signal to the throttle motor that adjusts the position of the throttle valve, a control signal to the ignition coil integrated with the igniter, and a control signal to the variable valve timing mechanism 150 that can change the opening / closing timing of the intake valve 128 It is output via. 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 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.

  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. Further, 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. The torque conversion operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that the torque is converted by the 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 battery 50 is met. Operation of the engine 22 is controlled so that power is output from the engine 22, and all or part of the power output from the engine 22 with charge / discharge of the battery 50 is torque generated by the planetary gear 30, the motor MG1, and the motor MG2. The required power is output to the drive shaft 36 with conversion. Charge-discharge drive mode for driving and controlling the motors MG1 and MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 36. 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, both are hereinafter referred to as the engine operation mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment, particularly the operation when traveling in the engine operation mode will be described. FIG. 5 is a flowchart showing an example of a drive control routine executed by the HVECU 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, first, the CPU of the HVECU 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the oil temperature Toil of the lubricating system oil of the engine 22, and the variable valve. Data required for control, such as a VVT drive request flag F that is set to 1 when a drive request for the timing mechanism 150 is made, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2, and the input and output limits Win and Wout of the battery 50 The input process is executed (step S100). Here, the oil temperature Toil of the lubricating oil of the engine 22 is input from the engine ECU 24 by communication from the temperature detected by the temperature sensor 151. The VVT drive request flag F is set to a value of 1 when a drive request for the variable valve timing mechanism 150 is made to change the opening / closing timing VT of the intake valve 128 by a flag setting routine (not shown), and this drive request is made. When the value is 0, a value set to 0 is input from the engine ECU 24 by communication. Further, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. It was supposed to be. Further, the input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 and the storage ratio SOC of the battery 50 and are input from the battery ECU 52 by communication.

  When the data is input in this way, the required torque Tr * to be output to the drive shaft 36 connected to the drive wheels 38a and 38b as the torque required for the vehicle based on the input accelerator opening Acc and the vehicle speed V, and the engine 22 The required required power Pe * is set (step S110). In the embodiment, the required torque Tr * is determined in advance by storing the relationship among the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in a ROM (not shown) as a required torque setting map, and the accelerator opening Acc and the vehicle speed. When V is given, the corresponding required torque Tr * is derived and set from the stored map. The required power Pe * can be calculated as the sum of the set required torque Tr * multiplied by the rotational speed Nr of the drive shaft 36 and the charge / discharge required power Pb * required by the battery 50 and the loss Loss. The rotational speed Nr of the drive shaft 36 can be obtained by multiplying the vehicle speed V by a conversion factor k (Nr = k · V), or the rotational speed Nm2 of the motor MG2 can be used.

  Subsequently, it is determined whether or not the VVT drive request flag F is 1 (step S120), and it is determined whether or not the input oil temperature Toil is equal to or higher than the temperature threshold Tref (step S130). Here, in the embodiment, the temperature threshold value Tref is variable because the oil viscosity decreases as the oil temperature Toil of the lubricating system of the engine 22 increases, and the oil pressure does not easily increase even when the mechanical pump 170 is driven to rotate. As a temperature that is high enough to cause the possibility that the lock by the lock pin 154 of the valve timing mechanism 150 is not released, a temperature that has been obtained in advance by experiments or the like (for example, 70 ° C., 80 ° C., 90 ° C., etc.) is used.

  When the VVT drive request flag F is 0, or when the VVT drive request flag F is 1 and the oil temperature Toil is less than the temperature threshold Tref, it is determined that the engine 22 is to be operated efficiently, and the engine 22 is to be operated efficiently. Is set as an execution operation line (step S140), and based on the set execution operation line and the required power Pe *, a target rotational speed Ne * as an operation point at which the engine 22 should be operated is set. A target torque Te * is set (step S160). Here, FIG. 6 shows an example of the optimum fuel efficiency operation line of the engine 22 set as the execution operation line, and the setting of the target rotational speed Ne * and the target torque Te *. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained by the intersection of the execution operation line and a curve with a constant required power Pe * (Ne * × Te *).

  Next, using the set target rotational speed Ne *, the rotational speed Nr of the drive shaft 36 (the rotational speed Nm2 of the motor MG2), and the gear ratio ρ of the planetary gear 30, the target rotational speed Nm1 of the motor MG1 is given by the following equation (1). * And the torque of the motor MG1 according to the relational expression (2) in the feedback control for rotating the motor MG1 at the target rotation speed Nm1 * using the calculated target rotation speed Nm1 * and the rotation speed Nm1 of the motor MG1. Command Tm1 * is calculated (step S170).

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

  Further, the torque limits Tmin and Tmax of the motor MG2 calculated by the following expressions (3) and (4) using the input / output limits Win and Wout of the battery 50, the torque command Tm1 * of the motor MG1 and the rotational speed Nm1, A value obtained by limiting the temporary motor torque Tm2tmp as a torque to be output from the motor MG2 calculated by the equation (5) using the required torque Tr *, the torque command Tm1 *, and the gear ratio ρ of the planetary gear 30 by the equation (6). As a torque command Tm2 * of the motor MG2 is set (step S180).

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

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S190), and the drive control routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * performs fuel injection control in the engine 22 such that the engine 22 is operated at an operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as ignition control, opening / closing timing control of the intake valve 128 (control of the variable valve timing mechanism 150 that changes the opening / closing timing according to the operating state of the engine 22 when the value 1 is set in the VVT drive request flag F), etc. Do. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. To do. By such control, the engine 22 is driven while the variable valve timing mechanism 150 is driven efficiently, and travels while outputting the required torque Tr * to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. Can do.

  In steps S120 and S130, when the VVT drive request flag F is 1 and the oil temperature Toil is equal to or higher than the temperature threshold Tref, it is determined that the lock by the lock pin 154 may not be released when the variable valve timing mechanism 150 is driven. Then, one of the high oil temperature operation lines is selected based on the oil temperature Toil and set as the execution operation line (step S150), and the engine 22 is selected based on the set execution operation line and the required power Pe *. The target rotational speed Ne * and the target torque Te * are set as operating points to be operated (step S160), and the target rotational speed Ne * and torque of the motor MG1 are set using the set target rotational speed Ne * of the engine 22. The command Tm1 * is set (step S170), and the requested torque Tr * and the torque command Tm1 * are set. Is used to set the torque command Tm2 * of the motor MG2 within the range of the input / output limits Win and Wout of the battery 50 (step S180), and the target rotational speed Ne * and target torque Te * of the engine 22 and the motors MG1 and MG2 are set. Torque commands Tm1 * and Tm2 * are transmitted to the engine ECU 24 and the motor ECU 40, respectively (step S190), and the drive control routine is terminated.

  FIG. 7 shows an example of an operation line for high oil temperature of the engine 22. In the figure, the fuel efficiency optimum operation line is indicated by a dotted line for comparison. As shown in the figure, the high oil temperature operation line is set to have a tendency that the rotational speed Ne of the engine 22 is higher than the fuel efficiency optimum operation line. In the embodiment, as the oil temperature Toil is higher than the temperature threshold value Tref, A plurality of high oil temperature operation lines (in the example of FIG. 7, the higher the oil temperature Toil is in the order of temperatures T1, T2, T3, the engine 22 in the operation line becomes higher than the fuel efficiency optimal operation line. Three high oil temperature operation lines) are determined so that the number of rotations of the oil increases. In the embodiment, the relationship between the oil temperature Toil and one of a plurality of high oil temperature operation lines corresponding to the oil temperature Toil is such that the lock pin 154 can be unlocked even when the oil temperature Toil is high. A predetermined map is stored in a ROM (not shown) as a relationship in which the number of revolutions of the engine 22 in the high oil temperature operation line is increased, and when the oil temperature Toil is given, the corresponding high oil temperature operation line is derived from the map. By doing so, one of a plurality of high oil temperature operation lines was selected. In this way, the variable valve timing mechanism 150 is requested to be driven, and the oil temperature Toil is higher than the temperature threshold Tref and the hydraulic pressure is not easily increased by the rotational driving of the mechanical pump 170. When there is a possibility that the lock by the lock pin 154 will not be released, the engine 22 is operated at the operation point on the high oil temperature operation line. Can be secured, and the lock pin body 154a in the variable valve timing mechanism 150 can be prevented from being pulled out of the groove 158.

  Therefore, when the abnormality determination of the variable valve timing mechanism 150 is performed when the engine 22 is operated with the driving of the variable valve timing mechanism 150, that is, whether or not the variable valve timing mechanism 150 operates according to the control signal. When determination is made using the cam position θca of the camshaft 129 (when it is determined that it is abnormal to continue the state where the control value and the detection value deviate beyond a predetermined range for a predetermined time), the lock by the lock pin 154 is released. Therefore, it is possible to suppress erroneous determination as abnormal even though the variable valve timing mechanism 150 is normal. If the lock by the lock pin 154 is not released when the engine 22 is operated, for example, at an operation point based on the required power Pe * and the operation line after the engine 22 is started in the locked state by the lock pin 154. When the engine 22 is started to be operated, or when the lock 22 is locked by the lock pin 154 according to the operation state during the operation of the engine 22, the lock is to be released according to the operation state of the engine 22. is there.

  Further, in the hybrid vehicle 20 of the embodiment, since a plurality of high oil temperature operation lines determined so that the rotational speed of the engine 22 is higher as the oil temperature Toil is higher than the temperature threshold value Tref, the lock pin 154 is used. Compared to the one that uses one high oil temperature operation line (for example, the high oil temperature operation line corresponding to the temperature T3 in the example of FIG. 7) that can be reliably unlocked, the engine 22 has an optimum fuel efficiency operation line. The degree of reduction in efficiency (deterioration of fuel consumption) due to driving at a driving point different from the upper driving point can be suppressed.

  According to the hybrid vehicle 20 of the embodiment described above, the optimum fuel efficiency is determined in advance by determining the relationship between the required power Pe * corresponding to the required torque Tr * and the rotational speed of the engine 22 and the torque in order to operate the engine 22 efficiently. The engine 22 is operated at an operation point based on the operation line, and the engine 22, the variable valve timing mechanism 150, and the motors MG1 and MG2 are controlled so as to run with the required torque Tr *. When the oil temperature Toil of the engine 22 is equal to or higher than a predetermined temperature threshold Tref, the engine 22 is operated at an operation point based on the required power Pe * and the high oil temperature operation line in which the engine 22 tends to have a higher rotational speed than the fuel efficiency optimum operation line. Is controlled so as to run with the required torque Tr *. Toil can be easily unlocked by the lock pin 154 of the variable valve timing mechanism 150 at the high temperature above the temperature threshold value Tref. As a result, the variable valve timing mechanism 150 can be easily operated when the engine 22 is operated.

  In the hybrid vehicle 20 of the embodiment, when the oil temperature Toil is equal to or higher than the temperature threshold value Tref, the target rotational speed Ne * and the target torque Te * as operating points of the engine 22 using one of a plurality of high oil temperature operation lines However, when the oil temperature Toil is equal to or higher than the temperature threshold value Tref, the engine 22 is used by using one operation line for high oil temperature that is set in advance so that the rotational speed of the engine 22 becomes higher than the fuel efficiency optimum operation line. It is good also as what sets the driving point of.

  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. 8, 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. 8) different from the connected axle (the axle to which the drive wheels 38a and 38b are connected).

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to “engine”, the variable valve timing mechanism 150 corresponds to “variable valve timing mechanism”, the motor MG1 corresponds to “first motor”, and the planetary gear 30 corresponds to “planetary gear”. The motor MG2 corresponds to the “second motor”, the battery 50 corresponds to the “battery”, and the HVECU 70 and the engine 22 that execute the drive control routine of FIG. 5 are controlled by the target rotational speed Ne * and the target torque Te *. An engine ECU 24 that performs fuel injection control, ignition control, opening / closing timing control of the intake valve 128, etc. so as to be operated at the indicated operating point, and a motor ECU 40 that controls the motors MG1, MG2 with torque commands Tm1 *, Tm2 *. Is a combination of the above and "control means".

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

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

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

  20, 120 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 39a, 39b wheel, 40 motor electronics Control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 52 electronic control unit for battery (battery ECU), 70 electronic control unit for hybrid (HVECU), 80 ignition switch, 81 shift Lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 12 8 intake valve, 129 intake camshaft, 150 variable valve timing mechanism, 151 temperature sensor, 152 VVT controller, 152a housing part, 152b vane part, 154 lock pin, 154a lock pin body, 154b spring, 156 oil control valve, 158 groove 159 oil passage, 162 timing chain, 164 timing gear, 170 mechanical pump, MG1, MG2 motor.

Claims (1)

Opening / closing timing of at least one of the intake valve and the exhaust valve of the engine by releasing the lock by the lock member using the pressure of hydraulic oil from the engine and a pump attached to the engine and driven by the rotation of the engine Variable valve timing mechanism, a first motor, a planetary gear 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 first motor A hybrid vehicle comprising: a second motor connected to the drive shaft; and a battery capable of exchanging electric power with the first motor and the second motor.
The engine is operated at an operation point based on a required power corresponding to a required driving force for traveling and an operation line for efficiency in which a relationship between the rotational speed and torque of the engine is predetermined in order to efficiently operate the engine. Control means for controlling the engine, the variable valve timing mechanism, the first motor, and the second motor so as to travel with the required driving force,
The control means is based on the required power and a high oil temperature operation line in which the engine speed tends to be higher than the efficiency operation line when the temperature of the hydraulic oil is equal to or higher than a predetermined temperature threshold. The engine is operated at an operating point and is controlled to travel with the required driving force.
A hybrid vehicle characterized by that.