JP2007176418A - Vehicle and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sufficient negative pressure while suppressing deterioration of fuel economy, when power from an internal combustion engine is unnecessary, but a negative pressure is necessary to provide braking force such as in deceleration. <P>SOLUTION: If a booster negative pressure Pbst is insufficient when there is no need to output power from an engine, oscillating torque for oscillating the engine within a range of 180 degrees is set in a torque command Tm1* of a motor MG1 (S200), and a throttle valve is opened and closed so as to supply a negative pressure to a brake booster following the oscillation. By this, a sufficient negative pressure can be provided while suppressing deterioration of fuel consumption, and sufficient braking force can be secured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle and a control method thereof, and more particularly to a vehicle equipped with an internal combustion engine having a throttle capable of adjusting an intake air amount and a control method thereof.

Conventionally, in this type of vehicle, when the brake pedal force increases while the engine is automatically stopped during deceleration, the brake booster is negatively driven by driving a motor capable of motoring the engine to idle the engine. One that increases the pressure has been proposed (see, for example, Patent Document 1). In this vehicle, by increasing the brake booster negative pressure in this way, the decrease in deceleration is suppressed while maintaining the engine shutdown state.
JP 2002-173909 A

  In the above-described vehicle, since the engine is motored by the motor, it is necessary to supply power from the battery to the motor. However, sufficient power is supplied depending on the state of the battery such as when the amount of power that can be discharged from the battery is small. It may not be possible. In this case, it is only necessary to start the engine, but driving the engine while decelerating reduces the fuel consumption.

  The vehicle of the present invention and its control method provide sufficient negative pressure while suppressing fuel consumption reduction when power from the internal combustion engine is not required, such as during deceleration, but negative pressure is required to obtain braking force. One of the purposes is to obtain. Another object of the vehicle and the control method thereof according to the present invention is to travel by outputting a required driving force including a braking force.

  The vehicle and the control method thereof according to the present invention employ the following means in order to achieve at least a part of the above-described object.

The vehicle of the present invention
A vehicle equipped with an internal combustion engine having a throttle capable of adjusting the amount of intake air,
A braking force applying means which is connected to the intake system of the internal combustion engine by a pipe line and applies a braking force to the vehicle using a braking request operation by an operator and a negative pressure of the intake system of the internal combustion engine;
Opened when the pressure on the intake system side of the internal combustion engine in the pipeline is smaller than the pressure on the braking force application means side, and the pressure on the intake system side of the internal combustion engine is the braking force application means Opening and closing means for closing when the pressure is greater than the pressure on the side,
An electric motor capable of rotating an output shaft of the internal combustion engine;
The motor is controlled so that the output shaft of the internal combustion engine swings within a predetermined angular range when a predetermined requirement condition for the negative pressure of the intake system of the internal combustion engine is satisfied in a state where power from the internal combustion engine is unnecessary. And a control means for controlling the internal combustion engine so that the throttle is opened and closed in response to the swinging;
It is a summary to provide.

  In the vehicle according to the present invention, the internal combustion engine output shaft swings within a predetermined angular range when a predetermined required condition for the negative pressure of the intake system of the internal combustion engine is satisfied in a state where power from the internal combustion engine is unnecessary. The electric motor capable of rotating the output shaft of the engine is controlled, and the internal combustion engine is controlled so that the throttle capable of adjusting the intake air amount of the internal combustion engine is opened and closed in response to the swing. In other words, the output shaft of the internal combustion engine is swung without rotating by the electric motor to move the piston up and down, and the throttle is opened and closed along with this swing to generate a negative pressure in the intake system of the internal combustion engine, which is controlled. It is supplied to the power applying means. The intake system of the internal combustion engine generates a negative pressure or a positive pressure by opening and closing the piston and opening / closing of the throttle, but the open / close means attached to the pipe line connecting the intake system of the internal combustion engine and the braking force applying means is provided. Opening when the pressure on the intake system side of the internal combustion engine is smaller than the pressure on the braking force applying means side, and closing when the pressure on the intake system side of the internal combustion engine is higher than the pressure on the braking force applying means side, thereby applying the braking force Only negative pressure is supplied to the means side. With this control, power from the internal combustion engine is not required, such as during deceleration travel, without rotating the output shaft of the internal combustion engine, but it is possible to suppress a decrease in fuel consumption when negative pressure is required to obtain braking force. Sufficient negative pressure can be obtained.

  In the vehicle according to the present invention, the predetermined angle range may be an angle range of an intake stroke of a part of the cylinders of the internal combustion engine. The control means is configured such that the throttle is fully closed when the piston of the cylinder in the intake stroke within the predetermined angle range moves to the bottom dead center side, and the throttle when the piston of the cylinder moves to the top dead center side. It can also be a means for controlling so that is fully opened.

  The vehicle according to the present invention further includes required driving force setting means for setting required driving force required for traveling, and a drive source capable of outputting power for traveling, wherein the control means is configured to It may be a means for controlling the internal combustion engine, the electric motor, and the drive source so as to travel with a required drive force. If it carries out like this, it can drive | work with a request | requirement driving force. In this case, the remaining shaft is connected to the three shafts of the output shaft of the internal combustion engine, the axle side, and the rotating shaft of the electric motor, and the remaining shaft is powered based on the power input / output to any two of the three shafts. It is also possible to include a three-axis power input / output means for inputting / outputting.

The vehicle control method of the present invention includes:
A braking force applied to the vehicle using an internal combustion engine having a throttle capable of adjusting the amount of intake air, a braking request operation performed by an operator connected to the intake system of the internal combustion engine and a negative pressure of the intake system of the internal combustion engine A braking force applying means for applying a pressure to the intake system side of the internal combustion engine, and is opened when the pressure on the intake system side of the internal combustion engine in the pipe is smaller than the pressure on the brake force applying means side. A vehicle control method comprising: opening / closing means that closes when the pressure is greater than the pressure on the braking force applying means side; and an electric motor capable of rotating an output shaft of the internal combustion engine,
The motor is controlled so that the output shaft of the internal combustion engine swings within a predetermined angle range when a predetermined requirement condition for the negative pressure of the intake system of the internal combustion engine is satisfied in a state where power from the internal combustion engine is unnecessary. And controlling the internal combustion engine so that the throttle is opened and closed in response to the swing,
It is characterized by that.

  In the vehicle control method of the present invention, when a predetermined requirement condition for the negative pressure of the intake system of the internal combustion engine is satisfied in a state where power from the internal combustion engine is unnecessary, the output shaft of the internal combustion engine swings within a predetermined angle range. The motor that can rotate the output shaft of the internal combustion engine is controlled so that the throttle that can adjust the intake air amount of the internal combustion engine is opened and closed in response to the swing. In other words, the output shaft of the internal combustion engine is swung without rotating by the electric motor to move the piston up and down, and the throttle is opened and closed along with this swing to generate a negative pressure in the intake system of the internal combustion engine, which is controlled. It is supplied to the power applying means. The intake system of the internal combustion engine generates a negative pressure or a positive pressure by opening and closing the piston and opening / closing of the throttle, but the open / close means attached to the pipe line connecting the intake system of the internal combustion engine and the braking force applying means is provided. Opening when the pressure on the intake system side of the internal combustion engine is smaller than the pressure on the braking force applying means side, and closing when the pressure on the intake system side of the internal combustion engine is higher than the pressure on the braking force applying means side, thereby applying the braking force Only negative pressure is supplied to the means side. With this control, power from the internal combustion engine is not required, such as during deceleration travel, without rotating the output shaft of the internal combustion engine, but it is possible to suppress a decrease in fuel consumption when negative pressure is required to obtain braking force. Sufficient negative pressure can be obtained.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, And a hybrid electronic control unit 70 for controlling the entire vehicle.

  The engine 22 is configured as a four-cylinder internal combustion engine capable of outputting power using a hydrocarbon-based fuel such as gasoline or light oil, and is cleaned by an air cleaner 122 attached to an intake pipe 121 as shown in FIG. The sucked air is sucked in through the throttle valve 124 and gasoline is injected from the fuel injection valve 126 provided in each cylinder to mix the sucked air and gasoline, and this mixture is passed through the intake valve 128. The fuel is sucked into the fuel chamber, explosively burned by an electric spark from the spark plug 130, and the reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 23. Exhaust gas from the engine 22 is discharged to the outside air through a purification device (three-way catalyst) 134 that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

  The engine 22 is controlled by an engine electronic control unit (hereinafter referred to as an engine ECU) 24. The engine ECU 24 is configured as a microprocessor centered on the CPU 24a, and includes a ROM 24b that stores a processing program, a RAM 24c that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 24a. . The engine ECU 24 includes signals from various sensors that detect the state of the engine 22, a crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 23, and a water temperature sensor 142 that detects the temperature of cooling water in the engine 22. From the cooling water temperature from the combustion chamber, the in-cylinder pressure Pin from the pressure sensor 143 installed in the combustion chamber, the intake valve 128 that performs intake and exhaust to the combustion chamber, and the cam position sensor 144 that detects the rotational position of the camshaft that opens and closes the exhaust valve Cam position, throttle position from throttle valve position sensor 146 for detecting the position of throttle valve 124, air flow meter signal AF from air flow meter 148 attached to the intake pipe, and temperature sensor also attached to the intake pipe Intake air temperature from 49, the air-fuel ratio AF from an air-fuel ratio sensor 135a, such as oxygen signal from an oxygen sensor 135b is input via the input port. Further, the engine ECU 24 sends various control signals for driving the engine 22, for example, a drive signal to each fuel injection valve 126 provided in each cylinder and a throttle motor 136 for adjusting the position of the throttle valve 124. Drive signal, a control signal to the ignition coil 138 integrated with the igniter, a control signal to the variable valve timing mechanism 150 capable of changing the opening / closing timing of the intake valve 128, 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. .

  Further, a negative pressure pipe 94 for supplying the negative pressure of the intake pipe 121 to the brake booster 90 is branched downstream of the throttle valve 124 of the intake pipe 121 of the engine 22, and the negative pressure pipe 94 includes a brake booster 90. A check valve 96 is attached so that the negative pressure is maintained. The brake booster 90 is configured as a well-known negative pressure servo type brake booster, and the driver applies a force acting on a diaphragm (not shown) due to a differential pressure between the pressure of the outside air and the negative pressure of the intake pipe 121 of the engine 22. In addition to the stepping force of stepping on the brake pedal 85, it acts as a force for pushing a piston (not shown) in the master cylinder 92.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. The battery ECU 52 also 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 battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. From the accelerator pedal position Acc, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the booster negative pressure Pbst from the negative pressure sensor 98 attached to the brake booster 90, and the vehicle speed sensor 88 Vehicle speed V and the like are input through the input port. As described above, the hybrid electronic control unit 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. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, 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 is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution and integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled to be output to each other, and a 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 ring gear shaft 32a. and so on.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when the negative pressure of the brake booster 90 is lowered when the power request to the engine 22 is unnecessary will be described. FIG. 3 is a flowchart showing an example of a drive control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, the CPU 72 of the hybrid electronic control unit 70 first starts from the accelerator pedal position Acc from the accelerator pedal position sensor 84, the brake pedal position BP from the brake pedal position sensor 86, and the vehicle speed sensor 88. Input data necessary for control, such as vehicle speed V, motor speed MG1, MG2 rotation speed Nm1, Nm2, battery 50 input / output limits Win, Wout, booster negative pressure Pbst from negative pressure sensor 98, crank angle CA of crankshaft 26 The process which performs is performed (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. The input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 detected by the temperature sensor 51 and the remaining capacity (SOC) of the battery 50 from the battery ECU 52 by communication. To do. Further, the crank angle CA is input through the engine ECU 24 as a signal from a crank position sensor 140 attached to the crankshaft 26.

  When the data is input in this way, it should be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the input accelerator opening Acc, brake pedal position BP, and vehicle speed V. The required torque Tr * and the required power Pe * required for the engine 22 are set (step S110). In the embodiment, the required torque Tr * is stored in the ROM 74 as a required torque setting map by predetermining the relationship between the accelerator opening Acc, the brake pedal position BP, the vehicle speed V, and the required torque Tr *. When Acc, brake pedal position BP, and vehicle speed V are given, the corresponding required torque Tr * is derived and set from the stored map. FIG. 4 shows an example of the required torque setting map. The required power Pe * can be calculated as the sum of the set required torque Tr * multiplied by the rotational speed Nr of the ring gear shaft 32a and the charge / discharge required power Pb * required by the battery 50 and the loss Loss. The rotation speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by the conversion factor k, or can be obtained by dividing the rotation speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35.

  Next, the set required power Pe * is compared with the threshold value Pref (step S120). In the embodiment, the threshold value Pref is set as a value near the lower limit value of the power range in which the engine 22 can be efficiently operated. When the required power Pe * is equal to or greater than the threshold value Pref, the target rotational speed Ne * and the target torque Te * of the engine 22 are set based on the set required power Pe * (step S130). This setting is performed based on the operation line for efficiently operating the engine 22 and the required power Pe *. FIG. 5 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and a curve with a constant required power Pe * (Ne * × Te *).

  Subsequently, using the target rotational speed Ne * of the engine 22, the rotational speed Nr (Nm2 / Gr) of the ring gear shaft 32a, and the gear ratio ρ of the power distribution and integration mechanism 30, the target rotational speed of the motor MG1 is expressed by the following equation (1). Nm1 * is calculated, and a torque command Tm1 * of the motor MG1 is calculated by the equation (2) based on the calculated target rotational speed Nm1 * and the current rotational speed Nm1 (step S140). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 6 is a collinear diagram showing the dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30. As shown in FIG. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by dividing the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown. Expression (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that torque Te * output from the engine 22 when the engine 22 is normally operated at the operation point of the target rotational speed Ne * and the target torque Te * is transmitted to the ring gear shaft 32a. Torque and torque that the torque Tm2 * output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term.

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

  When the torque command Tm1 * of the motor MG1 is calculated, the power consumption of the motor MG1 obtained by multiplying the input / output limits Win and Wout of the battery 50 and the calculated torque command Tm1 * of the motor MG1 by the current rotational speed Nm1 of the motor MG1 ( The torque limits Tmin and Tmax as upper and lower limits of the torque that may be output from the motor MG2 by dividing the deviation from the (generated power) by the rotation speed Nm2 of the motor MG2 are calculated by the following equations (3) and (4). At the same time (step S210), a temporary motor torque Tm2tmp as a torque to be output from the motor MG2 is calculated by the equation (5) using the required torque Tr *, the torque command Tm1 *, and the gear ratio ρ of the power distribution and integration mechanism 30 ( In step S220), the temporary motor torque Tm2tmp is controlled by the calculated torque limits Tmin and Tmax. Setting the torque command Tm2 * of the motor MG2 to a value (step S230). By setting the torque command Tm2 * of the motor MG2 in this way, the required torque Tr * output to the ring gear shaft 32a as the drive shaft is set as a torque limited within the range of the input / output limits Win and Wout of the battery 50. can do. Equation (5) can be easily derived from the collinear diagram of FIG. 6 described above.

Tmin = (Win-Tm1 * ・ Nm1) / Nm2 (3)
Tmax = (Wout-Tm1 * ・ Nm1) / Nm2 (4)
Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (5)

  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 S240), 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. 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.

  When it is determined in step S120 that the required power Pe * is less than the threshold value Pref, the booster negative pressure Pbst is compared with the threshold value Pbref (step S150). Here, the threshold value Pbref is set as a negative pressure of the brake booster 90 that can generate a sufficient negative pressure with respect to the depression of the brake pedal 85. When the booster negative pressure Pbst is smaller than the threshold value Pbref, that is, when a sufficient negative pressure is ensured, a value 0 is set to the target rotational speed Ne * of the engine 22 to stop the operation of the engine 22, and the target torque A value 0 is set in Te * (step S160), a value 0 is also set in the torque command Tm1 * of the motor MG1 (step S170), and a torque command Tm2 * of the motor MG2 is set by the processing in steps S210 to S230. Then, the target rotational speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are transmitted to the engine ECU 24 and the motor ECU 40 (step S240), and the drive control routine is ended. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * having a value of 0 stops the fuel injection and stops the ignition to stop the operation of the engine 22 when the engine 22 is in operation. When the operation is stopped, the operation stop state is maintained.

  When the booster negative pressure Pbst is larger than the threshold value Pbref in step S510, that is, when the negative pressure is insufficient, a negative pressure request instruction is output to the engine ECU 24 (step S180), and the target rotational speed Ne * of the engine 22 is 0. And a value 0 is also set for the target torque Te * (step S190). Based on the crank angle CA, the swing torque is set to the torque command Tm1 * of the motor MG1 (step S200), the torque command Tm2 * of the motor MG2 is set by the processing of steps S210 to S230, and the target rotational speed Ne *. The target torque Te * and torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the engine ECU 24 and the motor ECU 40 (step S240), and the drive control routine is terminated. The setting of the torque command Tm1 * in step S200 is executed by a swinging torque command setting routine illustrated in FIG. In this routine, first, the crank angle CA is corrected within a range of 180 degrees (step S300), and a crank angle difference ΔCA is calculated as a difference from the previous crank angle CA (step S310). Then, the sign of the crank angle difference ΔCA is determined (step S320), and the corrected crank angle CA is compared with the threshold value Cref1 and the threshold value Cref2 (steps S330 and S340). Here, the threshold Cref1 is set as a relatively small angle (for example, 20 degrees or 30 degrees) within a range of 180 degrees, and the threshold Cref2 is a relatively large angle (for example, 150 degrees or 160 degrees) within a range of 180 degrees. Degree). When the crank angle difference ΔCA is positive and the corrected crank angle CA is less than the threshold value Cref2, the value Tset set as the torque acting in the direction in which the crank angle CA increases is set as the torque command Tm1 * of the motor MG1 (step S350). ) When the corrected crank angle CA is greater than or equal to the threshold value Cref2 even if the crank angle difference ΔCA is positive, the torque command of the motor MG1 is set to a value Tset (−Tset) whose sign is changed so that the torque acts in the direction in which the crank angle CA decreases. Tm1 * is set (step S360). On the other hand, when the crank angle difference ΔCA is negative and the corrected crank angle CA is equal to or greater than the threshold value Cref1, a value Tset (−Tset) whose sign is changed so that the torque acts in a direction in which the crank angle CA decreases is a torque command for the motor MG1. Tm1 * is set (step S370). When the corrected crank angle CA is less than the threshold value Cref1 even if the crank angle difference ΔCA is negative, the value Tset is set to the torque command of the motor MG1 so that the torque acts in the direction in which the crank angle CA increases. Set to Tm1 * (step S380). That is, when the crank angle CA is increasing, a positive torque is set to the torque command Tm1 * until the threshold value Cref2 is exceeded, and after the crank angle CA exceeds the threshold value Cref2, it decreases and then decreases until it exceeds the threshold value Cref1. Is set to the torque command Tm1 *. As a result, the piston 132 in some cylinders of the engine 22 reciprocates at a position below the top dead center and a position above the bottom dead center. Even if such torque for swinging the engine 22 is output from the motor MG1, the torque as the reaction force is canceled by the motor MG2, so that the ring gear shaft 32a as the drive shaft has an input / output limit Win for the battery 50. , Wout can output the required torque Tr *.

  The engine ECU 24 that has received the negative pressure request instruction executes a swing throttle control routine illustrated in FIG. In this routine, first, the crank angle CA is corrected within a range of 180 degrees (step S400), and a crank angle difference ΔCA is calculated as a difference from the previous crank angle CA (step S410). Then, the sign of the crank angle difference ΔCA is determined (step S420). When the crank angle difference ΔCA is positive, the throttle valve 124 is fully opened (step S430), and when the crank angle difference ΔCA is negative, the throttle valve 124 is fully closed. (Step S440). Since the piston 132 moves downward when the crank angle difference ΔCA is negative, the throttle valve 124 is fully closed to apply a negative pressure to the negative pressure pipe 94 side, and when the crank angle difference ΔCA is positive, the piston 132 is moved. Is moving upward, the throttle valve 124 is fully opened so that a large positive pressure does not act on the negative pressure pipe 94 side. In the embodiment, since the check valve 96 is attached to the negative pressure pipe 94, only the negative pressure is supplied to the brake booster 90 side of the negative pressure pipe 94. As described above, when a negative pressure is requested, the piston 132 in some cylinders of the engine 22 reciprocates between a position below the top dead center and a position above the bottom dead center. Is fully closed or fully opened, a sufficient negative pressure can be supplied to the negative pressure tube 94 side.

  According to the hybrid vehicle 20 of the embodiment described above, when the booster negative pressure Pbst is insufficient when power does not need to be output from the engine 22, the engine 22 is swung within a range of 180 degrees and this swing is performed. Accordingly, by opening and closing the throttle valve 124 so as to supply a negative pressure to the negative pressure pipe 94, a sufficient negative pressure can be obtained while suppressing a decrease in fuel consumption. Thereby, sufficient braking force can be ensured. In addition, even when the engine 22 is swung in this way, the torque output to the ring gear shaft 32a due to the swing is canceled by the motor MG2, and therefore the ring gear shaft 32a has an input / output limit Win for the battery 50. , Wout can output the required torque Tr *.

  In the hybrid vehicle 20 of the embodiment, a four-cylinder internal combustion engine is used as the engine 22. However, the engine 22 is not limited to a four-cylinder internal combustion engine, and the engine 22 uses a three-cylinder or less internal combustion engine. Alternatively, an internal combustion engine having five or more cylinders may be used.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is shifted by the reduction gear 35 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. May be connected to an axle (an axle connected to the wheels 64a and 64b in FIG. 9) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 63a and 63b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, but the modified example of FIG. The hybrid vehicle 220 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor motor 230 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  In this way, the present invention is not only applied to a hybrid vehicle, but may be applied to a vehicle not equipped with an electric motor or a generator as long as the engine can be intermittently operated. For example, the present invention can be applied to an automobile in which the engine is automatically stopped by decoupling the engine from the axle side during deceleration.

  Moreover, it is not limited to what is applied to such a motor vehicle, It is good also as what is applied to vehicles other than a motor vehicle, and it is good also as a form of the control method of the internal combustion engine mounted in the vehicle.

  The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.

  The present invention can be used in the vehicle manufacturing industry.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. 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 an example of the map for request | requirement torque setting. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, and target rotational speed Ne * and target torque Te * are set. FIG. 4 is an explanatory diagram showing an example of a collinear diagram for dynamically explaining rotational elements of a power distribution and integration mechanism 30; 7 is a flowchart showing an example of a swinging torque command setting routine executed by the hybrid electronic control unit 70. 4 is a flowchart showing an example of a swing throttle control routine executed by an engine ECU 24. 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.

Explanation of symbols

20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 24a CPU, 24b ROM, 24c RAM, 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control Unit (battery ECU), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b driving wheel, 64a, 64b wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 0 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 Brake booster, 92 Master cylinder, 94 Negative pressure tube, 96 Check valve, 98 Negative pressure sensor, 121 Intake pipe, 122 Air cleaner, 124 Throttle valve, 126 Fuel injection valve, 128 Intake valve, 130 Spark plug, 132 Piston, 134 Purification device, 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, 14 Temperature sensor 150 variable valve timing mechanism. 230 Counter rotor motor, 232 Inner rotor 234 Outer rotor, MG1, MG2 motor.

Claims (6)

A vehicle equipped with an internal combustion engine having a throttle capable of adjusting the amount of intake air,
A braking force applying means which is connected to the intake system of the internal combustion engine by a pipe line and applies a braking force to the vehicle using a braking request operation by an operator and a negative pressure of the intake system of the internal combustion engine;
Opened when the pressure on the intake system side of the internal combustion engine in the pipeline is smaller than the pressure on the braking force application means side, and the pressure on the intake system side of the internal combustion engine is the braking force application means Opening and closing means for closing when the pressure is greater than the pressure on the side,
An electric motor capable of rotating an output shaft of the internal combustion engine;
The motor is controlled so that the output shaft of the internal combustion engine swings within a predetermined angular range when a predetermined requirement condition for the negative pressure of the intake system of the internal combustion engine is satisfied in a state where power from the internal combustion engine is unnecessary. And a control means for controlling the internal combustion engine so that the throttle is opened and closed in response to the swinging;
A vehicle comprising:   The vehicle according to claim 1, wherein the predetermined angle range is within an angle range of an intake stroke of a part of cylinders of the internal combustion engine.   The control means fully closes the throttle when the piston of the cylinder in the intake stroke within the predetermined angle range moves to the bottom dead center side, and fully opens the throttle when the piston of the cylinder moves to the top dead center side. The vehicle according to claim 1 or 2, which is means for controlling to become. A vehicle according to any one of claims 1 to 3,
Required driving force setting means for setting required driving force required for traveling;
A drive source capable of outputting driving power;
With
The said control means is a means which controls the said internal combustion engine, the said electric motor, and the said drive source so that it drive | works with the set said required drive force.   Connected to three shafts of the output shaft of the internal combustion engine, the axle side, and the rotating shaft of the electric motor, and inputs / outputs power to / from the remaining shaft based on power input / output to / from any two of the three shafts The vehicle according to claim 4, further comprising a three-axis power input / output means. A braking force applied to the vehicle using an internal combustion engine having a throttle capable of adjusting the amount of intake air, a braking request operation by an operator connected to the intake system of the internal combustion engine and a negative pressure of the intake system of the internal combustion engine A braking force applying means for applying a pressure to the intake system side of the internal combustion engine, and is opened when the pressure on the intake system side of the internal combustion engine in the pipe is smaller than the pressure on the brake force applying means side. A vehicle control method comprising: opening / closing means that closes when the pressure is larger than the pressure on the braking force applying means side; and an electric motor that can rotate the output shaft of the internal combustion engine,
The motor is controlled so that the output shaft of the internal combustion engine swings within a predetermined angular range when a predetermined required condition for the negative pressure of the intake system of the internal combustion engine is satisfied in a state where power from the internal combustion engine is unnecessary. And controlling the internal combustion engine so that the throttle is opened and closed in response to the swing,
A method for controlling a vehicle.

Images