JP6063896B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle.

  Patent Document 1 discloses a hybrid vehicle having at least an electric motor as a drive source, an engine, and a generator connected to the engine. The hybrid vehicle of Patent Document 1 stops engine operation by stopping at least one of fuel supply and ignition operation, and stops rotation due to the inertia of the engine accompanying the operation of the engine operation stop means. And a generator control means for operating the generator as an electric motor. In this hybrid type vehicle, the generator control means operates the generator connected to the engine as an electric motor to forcibly stop the rotation due to the inertia of the engine. For this reason, since the inertial rotation time of the engine is significantly shortened, the time for generating unpleasant noise and vibration associated with the inertial rotation is shortened, and the comfort and running feeling of the vehicle are improved.

  Patent Document 2 discloses a hybrid vehicle including an engine, a belt-type continuously variable transmission mechanism, a low brake or a high clutch, a motor / generator, left and right drive tires, and an integrated controller. In this hybrid vehicle, a low brake or a high clutch is disposed at a position downstream of the belt type continuously variable transmission mechanism, and power transmission is interrupted by opening the low brake or the high clutch. The motor / generator is disposed at a position downstream of the low brake or the high clutch, and is used for driving and regeneration. The integrated controller, which is a control device for the hybrid vehicle, decelerates the gear ratio of the belt-type continuously variable transmission mechanism to the low side after releasing the low brake or high clutch when requesting deceleration to stop fuel injection to the engine. Time control is performed. Further, the integrated controller prepares for the transition to the reacceleration request by delaying the decrease in the engine speed during the deceleration request.

Japanese Patent No. 30625567 JP2013-086649A

  An internal combustion engine as a drive source, a generator connected to the internal combustion engine, a transmission provided on the output side of the internal combustion engine, and an oil pump for providing a hydraulic pressure for changing a transmission gear ratio of the transmission In such a vehicle, when the drive of the internal combustion engine is stopped and the rotational speed of the internal combustion engine decreases due to the regenerative operation of the generator, control is performed so that the transmission is on the low gear side, that is, the gear ratio is increased. If the gear ratio of the transmission remains small without controlling the gear ratio, the inertia moment on the output side of the transmission when the internal combustion engine is restarted is too large, and the internal mechanism of the transmission slips and is normal. May not work. For this reason, as the rotational speed of the internal combustion engine decreases, the transmission is controlled to increase the transmission ratio using the hydraulic pressure from the oil pump. However, the mechanical oil is operated by the rotational power of the internal combustion engine. In the case of a pump, if the rotational speed of the internal combustion engine drops below a predetermined value, sufficient oil pressure is not provided from the oil pump to the transmission, and the transmission gear ratio cannot be changed. Thus, in the vehicle, the internal combustion engine may be restarted while the transmission gear ratio is not changed to the desired gear ratio when the internal combustion engine is stopped.

  The object of the present invention is to sufficiently prepare the state of the transmission for restarting the internal combustion engine when the rotational speed of the internal combustion engine is reduced by stopping the drive of the internal combustion engine and regenerating the generator. It is providing the control apparatus of the hybrid vehicle which can be performed in the next.

In order to achieve the above object, the invention described in claim 1
An internal combustion engine (for example, an internal combustion engine 109 in an embodiment described later);
A generator (for example, a generator 111 in an embodiment described later) for generating electric power by the rotational power of the internal combustion engine;
An electric motor driven by power supply from at least one of a capacitor and the generator (for example, an electric motor 107 in an embodiment described later);
A power connection / disconnection mechanism (for example, a lock-up clutch 119 in an embodiment described later) for connecting / disconnecting a power transmission path from the internal combustion engine to a drive wheel (for example, a drive wheel 129 in an embodiment described later);
A transmission for transmitting rotational power from the internal combustion engine to the drive wheels at a predetermined changeable gear ratio (for example, transmission 115 in an embodiment described later);
A mechanical oil pump (for example, a mechanical oil pump 117 in an embodiment to be described later) that operates by rotational power from the internal combustion engine and provides the transmission with a hydraulic pressure for changing the transmission gear ratio; With
A control device for a hybrid vehicle that travels by power from at least one of the electric motor and the internal combustion engine (for example, a management ECU 125 in an embodiment described later),
A torque control unit (for example, a torque control unit 157 in an embodiment described later) for controlling the torque of the generator driven by inertial rotation of the internal combustion engine when the driving of the internal combustion engine is stopped;
A gear ratio control unit (for example, a gear ratio control unit 151 in an embodiment described later) that controls the gear ratio of the transmission to be a target gear ratio when driving of the internal combustion engine is stopped;
A control method determination unit that determines any of a plurality of methods as a control method by the torque control unit until the transmission of the internal combustion engine is stopped and the transmission gear ratio reaches the target gear ratio. (For example, a control method determination unit 153 in an embodiment described later),
In the plurality of systems, the oil pump holds the oil pressure necessary to change the transmission gear ratio until the transmission gear ratio reaches the target gear ratio under the control of the gear ratio control unit. The torque of the generator is controlled so that the rotational speed of the internal combustion engine is maintained above a possible threshold value,
Among the plurality of systems, the amount of regeneration by the generator until the transmission gear ratio reaches the target transmission gear ratio is different.

The invention according to claim 2 is the invention according to claim 1,
The control method determination unit includes the plurality of methods.
While the drive of the internal combustion engine is stopped and the transmission gear ratio shifts to the target transmission gear ratio, the transmission gear ratio is determined based on the rotational speed of the internal combustion engine and the transmission gear ratio. A method in which the regenerative amount by the generator until the target speed ratio is reached is determined as a control method by the torque control unit.

In the invention according to claim 3, in the invention according to claim 1 or 2,
The plurality of methods include
When the rotational speed of the internal combustion engine is reduced to the threshold before the transmission gear ratio reaches the target gear ratio, a storage battery charged with regenerative energy by the generator (for example, an embodiment described later) A first method of maintaining the rotational speed of the internal combustion engine at or above the threshold by the driving torque of the generator by supplying power from the battery 101)
If the rotational speed of the internal combustion engine decreases to the threshold before the transmission gear ratio reaches the target gear ratio, the transmission gear ratio before the target gear ratio is reached. A second method for controlling the generator torque to be substantially zero;
Contains
The control method determination unit determines one of the first method and the second method as a control method by the torque control unit.

In the invention according to claim 4, in the invention according to claim 3,
When the rotational speed of the internal combustion engine decreases to the threshold value when the torque control unit is controlling the torque of the generator based on the second method, the control method determining unit is configured to perform the first method. Switch to.

The invention according to claim 5 is the invention according to any one of claims 1 to 4,
The generator that acts as a load of the internal combustion engine while the rotational speed of the internal combustion engine is decreasing based on the rotational speed of the internal combustion engine and the transmission gear ratio, and the states of the internal combustion engine and the transmission A control torque calculation unit (for example, a control torque calculation unit 155 in an embodiment described later).

According to the first to fifth aspects of the invention, when the rotational speed of the internal combustion engine is reduced by the regenerative drive of the generator after the drive of the internal combustion engine is stopped, the torque of the generator is controlled by the torque control unit. Thus, it is possible to sufficiently prepare the state of the transmission for restarting the internal combustion engine. For this reason, when the internal combustion engine is stopped, the transmission is changed to a gear ratio suitable for the next start of the internal combustion engine. That is, when the internal combustion engine is started next time, an excessive moment of inertia is not applied to the output side of the transmission, and the transmission is not hindered.
In addition, since the control method by the torque control unit includes a plurality of methods in which the amount of regeneration by the generator until the transmission gear ratio reaches the target gear ratio is different, the transmission gear ratio becomes the target gear ratio. A method that can perform more regeneration by the generator until it reaches is selected. For this reason, the regeneration by the generator until the gear ratio reaches the target gear ratio can be maximized.

  According to the invention of claim 4, the transmission gear ratio can be reliably changed to the target gear ratio.

It is a block diagram which shows the internal structure of series / parallel HEV. It is the figure which showed roughly the principal part of the drive system in the hybrid vehicle shown in FIG. It is a figure which shows the transition between each drive state and driving mode in a hybrid vehicle at the time of (a) EV driving mode, (b) series driving mode, (c) engine driving mode, and (d) parallel driving mode. It is a figure which shows the drive state of a hybrid vehicle when it switches from series drive mode to EV drive mode. It is a block diagram which shows the internal structure of management ECU. (A) is a graph which shows an example of the time change of the rotation speed Ne of the internal combustion engine which changes according to the torque of the generator controlled based on the 1st system, and the said control, (b) It is a graph which shows an example of the time change of the rotation speed Ne of the internal combustion engine which changes according to the torque of the generator controlled based on 2 systems, and the said control. It is a flowchart which shows the operation | movement at the time of the control system determination part of management ECU determining a control system. It is a figure which respectively shows the area | region where the 1st system is selected, and the area | region where the 2nd system is selected on the map of the rotation speed Ne of an internal combustion engine, and the transmission gear ratio Ract. It is a flowchart which shows operation | movement of management ECU when the drive of an internal combustion engine is stopped. It is a flowchart which shows operation | movement of management ECU when the drive of an internal combustion engine is stopped. It is a flowchart which shows operation | movement of management ECU when the drive of an internal combustion engine is stopped. 12 is a flowchart showing a subroutine of steps S111 and S131 by the control torque calculation unit shown in FIGS.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A HEV (Hybrid Electrical Vehicle) includes an electric motor and an internal combustion engine, and travels by the driving force of the electric motor and / or the internal combustion engine according to the traveling state of the vehicle. There are two types of HEVs: a series method and a parallel method. The series-type HEV travels by the power of the electric motor. The internal combustion engine is used only for power generation, and the electric power generated by the power generator by the power of the internal combustion engine is charged in the capacitor or supplied to the electric motor.

  There are two series-type HEV driving modes: “EV driving mode” and “ECVT driving mode”. In the EV travel mode, HEV travels by the driving force of an electric motor that is driven by power supply from a capacitor. At this time, the internal combustion engine is not driven. In the ECVT travel mode, the HEV travels by the driving force of an electric motor that is driven by the supply of power from both the power storage device and the generator or the supply of power from only the generator. At this time, the internal combustion engine is driven for power generation in the generator.

  The parallel HEV travels by the driving force of one or both of the electric motor and the internal combustion engine. In particular, a mode in which a parallel HEV travels using only the driving force of the internal combustion engine is referred to as an “overdrive (OD) travel mode”.

  A series / parallel HEV in which both the above systems are combined is also known. In this method, the driving force transmission system is switched between the series method and the parallel method by opening or closing (engaging / disconnecting) the clutch according to the running state of the vehicle. In particular, the clutch is disengaged during low-to-medium speed acceleration traveling and is configured as a series system, and the clutch is engaged during medium-to-high speed steady traveling (cruise traveling) to form a parallel structure.

  FIG. 1 is a block diagram showing the internal configuration of a series / parallel HEV. As shown in FIG. 1, a series / parallel HEV (hereinafter referred to as “hybrid vehicle”) includes a battery (BATT) 101, a converter (CONV) 103, a first inverter (first INV) 105, an electric motor ( Mot) 107, internal combustion engine (ENG) 109, generator (GEN) 111, second inverter (second INV) 113, transmission (T / M) 115, mechanical oil pump (MOP) 117, , A lock-up clutch 119, an engine temperature sensor 121, a rotation speed sensor 123, an oil temperature sensor 124, and a management ECU 125. In FIG. 1, dotted arrows indicate value data, solid arrows indicate control signals including instruction contents, and double arrows indicate power transmission.

  The storage battery 101 has a plurality of storage cells connected in series, and supplies a high voltage of, for example, 100 to 200V. The storage cell is, for example, a lithium ion battery or a nickel metal hydride battery. Converter 103 boosts or steps down the DC output voltage of battery 101 while maintaining DC. The first inverter 105 converts a DC voltage into an AC voltage and supplies a three-phase current to the electric motor 107. Further, the first inverter 105 converts the AC voltage input during the regenerative operation of the electric motor 107 into a DC voltage and charges the battery 101.

  The electric motor 107 generates power for running the hybrid vehicle. Torque generated by the electric motor 107 is transmitted to the drive wheels 129 via the drive shaft 127. In addition, the electric motor 107 operates as a generator during regenerative braking, and the electric power generated by the electric motor 107 is charged in the capacitor 101.

  The internal combustion engine 109 is used only to drive the generator 111 when the hybrid vehicle travels in series with the lock-up clutch 119 opened. However, when the lock-up clutch 119 is engaged, the output of the internal combustion engine 109 is transmitted to the drive wheels 129 via the transmission 115, the lock-up clutch 119 and the drive shaft 127 as mechanical energy for the hybrid vehicle to travel. Is done.

  The generator 111 is driven by the power of the internal combustion engine 109 to generate electric power. The electric power generated by the generator 111 is charged in the battery 101 or supplied to the electric motor 107 via the second inverter 113 and the first inverter 105. The generator 111 generates rotational power when starting the internal combustion engine 109. The second inverter 113 converts the AC voltage generated by the generator 111 into a DC voltage. The electric power converted by the second inverter 113 is charged in the battery 101 or supplied to the electric motor 107 via the first inverter 105.

  The transmission 115 is a continuously variable transmission that can change the gear ratio steplessly. The transmission 115 converts the driving force from the internal combustion engine 109 into a rotation speed and torque at a set transmission gear ratio, and transmits them to the drive shaft 127. The change of the gear ratio in the transmission 115 is performed by the hydraulic pressure obtained from the mechanical oil pump 117. A mechanical oil pump (hereinafter simply referred to as an “oil pump”) 117 is operated by the rotational power of the internal combustion engine 109 or the drive shaft 127, and provides the transmission 115 with hydraulic pressure for changing the gear ratio in the transmission 115. And provides hydraulic pressure for the lock-up clutch 119 to operate. The lock-up clutch 119 connects and disconnects the driving force transmission path from the internal combustion engine 109 to the driving wheels 129 based on an instruction from the management ECU 125. The connection / disconnection operation of the transmission path by the lock-up clutch 119 is also performed by the hydraulic pressure obtained from the oil pump 117.

  The engine temperature sensor 121 measures the temperature of the internal combustion engine 109 (hereinafter referred to as “engine temperature”) Teng. A signal indicating the engine temperature Teng measured by the engine temperature sensor 121 is sent to the management ECU 125. The rotational speed sensor 123 detects the rotational speed Ne of the internal combustion engine 109. A signal indicating the rotational speed Ne detected by the rotational speed sensor 123 is sent to the management ECU 125. The oil temperature sensor 124 measures the temperature Ttm of the hydraulic oil provided from the oil pump 117 in order to change the gear ratio of the transmission 115. A signal indicating the temperature Ttm of the hydraulic oil measured by the oil temperature sensor 124 is sent to the management ECU 125.

  The management ECU 125 performs control of the electric motor 107, the internal combustion engine 109, the generator 111, and the transmission 115, connection / disconnection of the clutch 119, switching of a travel mode described below, and the like. Details of the management ECU 125 will be described later.

  FIG. 2 is a diagram schematically showing the main part of the drive system in the hybrid vehicle shown in FIG. Also, FIG. 3 shows transitions between driving states and travel modes when the hybrid vehicle is in (a) EV travel mode, (b) series travel mode, (c) engine travel mode, and (d) parallel travel mode. FIG.

  In the hybrid vehicle in the EV travel mode, as shown in FIG. 3A, the lockup clutch 119 is released and the internal combustion engine 109 is stopped. The hybrid vehicle travels by the driving force of the electric motor 107 that is driven by the power supply from the battery 101.

  In the hybrid vehicle in the series travel mode, as shown in FIG. 3B, the lockup clutch 119 is released, and the electric motor 107 outputs the required driving force based on the accelerator pedal opening (AP opening), the vehicle speed, and the like. The internal combustion engine 109 is operated to supply possible power. The hybrid vehicle travels by the driving force of the electric motor 107 that is driven by the power supply from the generator 111. In the hybrid vehicle in the series travel mode, the internal combustion engine 109 is driven at the operating point on the BSFC (Brake Specific Fuel Consumption) bottom line, and the surplus electric power is reduced as indicated by the one-dot chain line in FIG. The battery 101 may be charged. In addition, when the electric power obtained by driving the internal combustion engine 109 at the operating point on the BSFC bottom line is less than the required driving force, in addition to the power supply from the generator 111, two points are shown in FIG. As indicated by a chain line, auxiliary power from the battery 101 may be supplied to the electric motor 107.

  In the hybrid vehicle in the engine travel mode, as shown in FIG. 3C, the lockup clutch 119 is engaged, and the hybrid vehicle travels with the driving force of the internal combustion engine 109. When traveling in the engine travel mode, the rotor of the electric motor 107 and the rotor of the generator 111 are rotated along with the driving of the internal combustion engine 109. However, the management ECU 125 performs zero current control so that the generator 111 is in a no-load state. In the hybrid vehicle in the engine running mode, the internal combustion engine 109 is driven at the operating point on the BSFC bottom line, and is generated by the electric motor 107 driven as a generator, as indicated by a one-dot chain line in FIG. The stored power may be charged in the battery 101.

  In the hybrid vehicle in the parallel travel mode, as shown in FIG. 3D, the lockup clutch 119 is engaged, and the hybrid vehicle travels by the driving force of both the internal combustion engine 109 and the electric motor 107. When traveling in the parallel travel mode, the rotor of the generator 111 is rotated along with the drive of the internal combustion engine 109. However, the management ECU 125 performs zero current control so that the generator 111 is in a no-load state.

  Which of the travel modes described above is selected is determined by the management ECU 125 based on the AP opening, the vehicle speed, and the like. The EV travel mode shown in FIG. 3A is selected when the hybrid vehicle is traveling at low speed cruise (steady travel), at low speed acceleration, or at medium speed. Also, the engine travel mode shown in FIG. 3C is selected during medium speed acceleration travel or high speed cruise travel. Further, the parallel traveling mode shown in FIG. 3D is selected during high-speed acceleration traveling.

  The series travel mode shown in FIG. 3B is a vehicle speed at which the EV travel mode can be selected, and the remaining capacity (SOC: State of Charge) of the battery 101 is very low. It is selected when the vehicle speed is so low that the lockup clutch 119 cannot be engaged by hydraulic pressure. Therefore, for example, even when the SOC of the battery 101 is very low, the engine travel mode is selected and the series travel mode is selected when the vehicle speed is such that the oil pump 117 can provide hydraulic pressure capable of engaging the lockup clutch 119. Not.

  FIG. 4 is a diagram illustrating a driving state of the hybrid vehicle when the engine traveling mode or the parallel traveling mode is switched to the EV traveling mode. As shown in FIG. 4, when the driving of the internal combustion engine 109 is stopped in accordance with switching from the engine travel mode or the parallel travel mode to the EV travel mode, the internal combustion engine 109 rotates inertially. As a result, the generator 111 is driven. At this time, the torque of the generator 111 is controlled, and the regenerative energy obtained by the generator 111 is charged in the capacitor 101.

  The management ECU 125 stops the driving of the internal combustion engine 109 and switches from the “engine traveling mode” or “parallel traveling mode” to the “EV traveling mode”, and the torque of the generator 111 driven by inertial rotation of the internal combustion engine 109 To control. Hereinafter, the control performed by the management ECU 125 will be described.

  FIG. 5 is a block diagram showing an internal configuration of the management ECU 125. As shown in FIG. 5, the management ECU 125 includes a transmission ratio control unit 151, a control method determination unit 153, a control torque calculation unit 155, and a torque control unit 157. The gear ratio control unit 151 controls the gear ratio (ratio) Ract of the transmission 115 to be the target gear ratio Rtgt when the driving of the internal combustion engine 109 is stopped. Note that the gear ratio Ract in the transmission 115 is changed by the hydraulic pressure obtained from the mechanical oil pump 117. The control method determination unit 153 determines the torque control method of the generator 111 until the drive of the internal combustion engine 109 is stopped and the speed ratio Ract of the transmission 115 reaches the target speed ratio Rtgt. In the present embodiment, the first method and the second method can be used as the torque control method of the generator 111. The control method determination unit 153 determines the torque control method of the generator 111 by selecting either the first method or the second method. The control torque calculation unit 155 calculates the torque of the generator 111 that acts as a load on the internal combustion engine 109 while the rotational speed Ne of the internal combustion engine 109 is decreasing. The torque control unit 157 controls the torque of the generator 111 based on the control method determined by the control method determining unit 153 when the driving of the internal combustion engine 109 is stopped. Note that the magnitude of the torque of the generator 111 is controlled by the frequency of the switching control in the second inverter 113.

  Hereinafter, the first method and the second method, which are control methods that can be selected by the torque control unit 157, will be described. FIG. 6A is a graph showing an example of the temporal change of the torque of the generator 111 controlled based on the first method and the rotational speed Ne of the internal combustion engine 109 that changes according to the control. FIG. 6B is a graph showing an example of the temporal change of the torque of the generator 111 controlled based on the second method and the rotational speed Ne of the internal combustion engine 109 that changes according to the control. 6A and 6B, the transmission gear ratio Ract of the transmission 115 is controlled to change from the time 0 to the target transmission gear ratio Rtgt.

  In the first method, as shown in FIG. 6A, when the driving of the internal combustion engine 109 is stopped, the generator 111 is configured so that the torque calculated by the control torque calculation unit 155 serves as a load of the internal combustion engine 109. The load torque is controlled. The torque control of the generator 111 at this time is referred to as “plus torque control”. In the first method, when the rotational speed Ne of the internal combustion engine 109 decreases to the first threshold value th1 before the transmission gear ratio Ract of the transmission 115 reaches the target transmission gear ratio Rtgt, the generator 111 is turned on. 109 is driven, and the driving torque of the generator 111 is controlled so that the rotational speed Ne of the internal combustion engine 109 does not become less than the first threshold value th1. The torque control of the generator 111 at this time is referred to as “minus torque control”. The negative torque control is performed until the transmission gear ratio Ract of the transmission 115 reaches the target transmission gear ratio Rtgt. The first threshold th1 is the number of revolutions of the internal combustion engine 109 at which the oil pump 117 can provide the hydraulic pressure at which the transmission 115 can change the speed ratio Ract. It may be a variable value corresponding to the inertia and friction.

  In the second method, as shown in FIG. 6B, when the driving of the internal combustion engine 109 is stopped, the generator 111 is operated so as to act as a load of the internal combustion engine 109 with the torque calculated by the control torque calculation unit 155. Plus torque control. In the second method, when the speed Ne of the internal combustion engine 109 decreases to the second threshold value th2 before the speed ratio Ract of the transmission 115 reaches the target speed ratio Rtgt, the torque of the generator 111 is increased. Controlled to be zero. The torque control of the generator 111 at this time is referred to as “zero torque control”. The second threshold th2 is higher than the first threshold th1. The zero torque control is performed until the speed ratio Ract of the transmission 115 reaches the target speed ratio Rtgt or until the rotational speed Ne of the internal combustion engine 109 decreases to the first threshold value th1. However, when the rotational speed Ne of the internal combustion engine 109 decreases to the first threshold value th1 during the zero torque control, the torque control unit 157 causes the generator to prevent the rotational speed Ne of the internal combustion engine 109 from becoming less than the first threshold value th1. By controlling the driving torque of 111, minus torque control similar to the first method is performed.

  Regardless of whether the control method is the first method or the second method, the torque control unit 157 increases the power of the generator 111 with a predetermined torque after the speed ratio Ract of the transmission 115 reaches the target speed ratio Rtgt. Perform torque control.

  Next, a control method determination method by the control method determination unit 153 will be described. FIG. 7 is a flowchart showing an operation when the control method determination unit 153 determines the control method. As shown in FIG. 7, the control method determination unit 153 determines that the speed ratio Ract is a target based on the current speed ratio Ract of the transmission 115, the target speed ratio Rtgt, and the change speed Vratio of the speed ratio Ract in the transmission 115. A time (shift time Tratio) until the speed ratio Rtgt is reached is calculated (step S11). Next, the control method determination unit 153 sets the inertia I upstream of the lockup clutch 119, that is, the inertia I of the internal combustion engine 109, the inertia Ieng of the internal combustion engine 109, the inertia Itm of the transmission 115, the inertia Igen of the generator 111, And other inertia Ietc (step S13). The inertia Itm of the transmission 115 is calculated based on the gear ratio Ract of the transmission 115.

  Next, the control method determination unit 153 sets the friction F upstream of the lockup clutch 119, that is, the internal combustion engine 109 side friction Feng, the internal combustion engine 109 friction Feng, the transmission 115 friction Ftm, the generator 111 friction Fgen, And other friction Fetc are calculated (step S15). Note that the friction Feng of the internal combustion engine 109 is calculated based on the rotational speed Ne of the internal combustion engine 109 and the engine temperature Teng. Further, the friction Ftm of the transmission 115 is calculated based on the temperature Ttm of the hydraulic oil of the oil pump 117. Further, the other friction Fetc is calculated based on the rotational speed Ne of the internal combustion engine 109.

  Next, the control method determination unit 153 uses the first method to reduce the rotational speed Ne of the internal combustion engine 109 to the first threshold th1 with the shift time Tratio. Is calculated based on the shift time Tratio, the inertia I calculated in step S203, the friction F calculated in step S205, the rotational speed Ne, and the first threshold value th1, and the shift time Tratio is calculated by the second method. The regenerative amount P2reg obtained by the regenerative operation of the generator 111 when the rotational speed Ne of the internal combustion engine 109 is reduced to the first threshold th1 is calculated in the shift time Tratio, the inertia I calculated in step S203, and in step S205. Calculation is made based on the friction F, the rotational speed Ne, the first threshold value th1, and the second threshold value th2 (step S17).

  Finally, the control method determination unit 153 compares the regeneration amount P1reg calculated in step S17 with the regeneration amount P2reg (step S19), and if P1reg ≧ P2reg, determines the first method (step S21), and P1reg < If it is P2reg, the second method is determined (step S23).

  FIG. 8 is a diagram showing a plurality of regions on a map of the rotational speed Ne of the internal combustion engine 109 and the speed ratio Ract of the transmission 115. The target speed ratio Rtgt is set on the low gear side shown in FIG. Whether the control method determination unit 153 determines the first method or the second method is determined based on the operating point determined from the rotational speed Ne of the internal combustion engine 109 and the gear ratio Ract of the transmission 115 (hereinafter simply referred to as “operation”). It depends on which area on the map shown in FIG.

  In the present embodiment, when the operating point belongs to the first region 201 shown in FIG. 8, that is, the region on the low gear side and the high rotation high gear side, the control method determination unit 153 performs the procedure shown in FIG. Determined by the method. When the operating point belongs to the first region 201, if the transmission 115 is on the low gear side, the time required until the transmission gear ratio Ract of the transmission 115 reaches the target gear ratio Rtgt is short. If it is high, it takes time to decrease to the threshold values th1 and th2. Therefore, it is possible to secure time for changing the gear ratio Ract of the transmission 115. That is, the first region 201 is a region where the torque control unit 157 is unlikely to perform minus torque control even when the torque control of the generator 11 is performed by the first method. As a result, when the operating point belongs to the first region 201, when the torque control of the generator 111 by the first method is performed, the regeneration by the generator 111 until the speed ratio Ract reaches the target speed ratio Rtgt is maximized. Likely to do.

  On the other hand, when the operating point belongs to the second area 203 shown in FIG. 8, that is, the area on the high gear side, when the control method determining unit 153 performs the procedure shown in FIG. When the operating point belongs to the second region 203, if the transmission 115 is on the high gear side, it takes time until the transmission gear ratio Ract of the transmission 115 reaches the target transmission gear ratio Rtgt. Therefore, the transmission gear ratio Ract is equal to the target transmission gear ratio Rtgt. There is a high possibility that the rotational speed Ne reaches the threshold value th1 before reaching. Therefore, when the operating point belongs to the second region 203, when the torque control of the generator 111 according to the second method is performed as compared with the first method, the generator until the speed ratio Ract reaches the target speed ratio Rtgt. There is a high possibility that the regeneration by 111 will be maximized.

  When the operating point belongs to the third region 205 shown in FIG. 8, that is, the region on the low-rotation high-gear side, when the control method determining unit 153 performs the procedure shown in FIG. When the operating point belongs to the third region 205, it is very likely that the rotational speed Ne reaches the threshold value th1 before the speed ratio Ract reaches the target speed ratio Rtgt. In this case, even if the torque control by the second method is performed, it is highly likely that the negative torque control is performed after the zero torque control is performed. Therefore, when the operating point belongs to the third region 205, the generator 111 by the first method When torque control is performed, there is a high possibility that regeneration by the generator 111 until the speed ratio Ract reaches the target speed ratio Rtgt is maximized.

  In the above description, the control method determination unit 153 determines the torque control method of the generator 111 as either the first method or the second method by performing the procedure shown in FIG. Using the map shown, the first method may be determined when the operating point belongs to the first region 201 or the third region 205, and the second method may be determined when the operating point belongs to the second region 203.

  9 to 11 are flowcharts showing the operation of the management ECU 125 when the driving of the internal combustion engine 109 is stopped. As shown in FIGS. 9 to 11, the management ECU 125 determines whether or not the driving of the internal combustion engine 109 is stopped when the hybrid vehicle travel mode is switched from the engine travel mode or the parallel travel mode to the EV travel mode. (Step S101), and when the driving of the internal combustion engine 109 is stopped, the process proceeds to step S103. In step S103, the control method determination unit 153 performs the procedure shown in FIG. 7 and determines the torque control method of the generator 111. It is determined whether the control method determined in step S103 is the first method or the second method (step S105). If the control method is the first method, the process proceeds to step S111 shown in FIG. The process proceeds to step S131.

  In step S111 shown in FIG. 10, the control torque calculation unit 155 calculates the torque of the generator 111 that acts as a load on the internal combustion engine 109 while the rotational speed Ne of the internal combustion engine 109 is decreasing. Next, the torque control unit 157 performs plus torque control of the generator 111 so that the torque calculated in step S111 is obtained, and the transmission ratio control unit 151 causes the transmission ratio Ract of the transmission 115 to become the target transmission ratio Rtgt. Control (step S113). Next, the torque control unit 157 determines whether the speed ratio Ract has become larger than the target speed ratio Rtgt (Ract> Rtgt) (step S115). If Ract> Rtgt, the process proceeds to step S117, where Ract ≦ Rtgt If so, the process proceeds to step S119. In step S117, the torque control unit 157 performs plus torque control of the generator 111.

  In step S119, the torque control unit 157 determines whether the rotational speed Ne of the internal combustion engine 109 has decreased to the first threshold value th1 or less (Ne ≦ th1). If Ne ≦ th1, the process proceeds to step S121. If> th1, the process returns to step S103. In step S121, the torque control unit 157 performs minus torque control of the generator 111 so that the rotational speed Ne of the internal combustion engine 109 does not become less than the first threshold th1, and drives the internal combustion engine 109 by the generator 111. . Next, the torque control unit 157 determines whether the speed ratio Ract has become larger than the target speed ratio Rtgt (Ract> Rtgt) (step S123). If Ract> Rtgt, the process proceeds to step S117, where Ract ≦ Rtgt If so, the process returns to step S121.

  In step S131 shown in FIG. 11, the control torque calculation unit 155 calculates the torque of the generator 111 that acts as a load on the internal combustion engine 109 while the rotational speed Ne of the internal combustion engine 109 is decreasing. Next, the torque control unit 157 performs positive torque control of the generator 111 so that the torque calculated in step S131 is obtained, and the transmission ratio control unit 151 causes the transmission ratio Ract of the transmission 115 to become the target transmission ratio Rtgt. Control is performed (step S133). Next, the torque control unit 157 determines whether the speed ratio Ract has become larger than the target speed ratio Rtgt (Ract> Rtgt) (step S135). If Ract> Rtgt, the process proceeds to step S137, where Ract ≦ Rtgt If so, the process proceeds to step S139. In step S137, the torque control unit 157 performs plus torque control of the generator 111.

  In step S139, the torque control unit 157 determines whether the rotational speed Ne of the internal combustion engine 109 has decreased to a second threshold value th2 or less (Ne ≦ th2). If Ne ≦ th2, the process proceeds to step S141. If> th2, the process proceeds to step S137. In step S141, the torque control unit 157 performs zero torque control of the generator 111 so that the torque of the generator 111 becomes zero. Next, the torque control unit 157 determines whether the rotational speed Ne of the internal combustion engine 109 has decreased to a first threshold value th1 or less (Ne ≦ th1). If Ne ≦ th1, the process proceeds to step S145, where Ne> If it is th1, the process proceeds to step S147. In step S145, the torque control unit 157 switches the torque control method of the generator 111 to the first method so that the rotational speed Ne of the internal combustion engine 109 does not become less than the first threshold th1, and the negative torque of the generator 111 is reduced. Take control. Next, the torque control unit 157 determines whether the speed ratio Ract has become larger than the target speed ratio Rtgt (Ract> Rtgt) (step S147). If Ract> Rtgt, the process proceeds to step S137, where Ract ≦ Rtgt If so, the process returns to step S139.

  FIG. 12 is a flowchart showing a subroutine of steps S111 and S131 by the control torque calculation unit 155 shown in FIGS. As shown in FIG. 12, the control torque calculation unit 155 determines the torque Tcal of the generator 111 that reduces the rotational speed Ne of the internal combustion engine 109 to the first threshold th1 by the shift time Tratio, the shift time Tratio, step S203. Calculation is performed based on the calculated inertia I, the friction F calculated in step S205, the rotational speed Ne, and the first threshold value th1 (step S201). Next, the control torque calculation unit 155 uses the larger of the torque Tcal calculated in step S201 and the maximum torque Tgenmax in the generator 111 as the load of the internal combustion engine 109 while the rotational speed Ne of the internal combustion engine 109 is decreasing. Derived as the torque T of the working generator 111 (step S203).

  As described above, according to the present embodiment, when the driving of the internal combustion engine 109 is stopped, the rotational speed Ne of the internal combustion engine 109 becomes the threshold value before the speed ratio Ract reaches the target speed ratio Rtgt. Even when it reaches th1, the rotational speed Ne is maintained at the threshold value th1 or more until the speed ratio Ract reaches the target speed ratio Rtgt. Since the gear ratio Ract of the transmission 115 can be changed if the rotational speed Ne is equal to or greater than the threshold th1, the transmission 115 is changed to a gear ratio suitable for the next start of the internal combustion engine 109 when the internal combustion engine 109 is stopped. It will be in the state. That is, when the internal combustion engine 109 is started next time, an excessive moment of inertia is not applied to the output side of the transmission 115, and the transmission 115 is not hindered.

  Further, it is possible to select the torque control method of the generator 111 when the drive of the internal combustion engine 109 is stopped and the rotational speed of the internal combustion engine 109 decreases, and the transmission gear ratio Ract of the transmission 115 becomes the target transmission gear ratio Rtgt. A method capable of performing more regeneration by the generator 111 until it reaches is selected. That is, depending on the state of the internal combustion engine 109 and the state of the transmission 115, the method in which the regeneration amount by the generator 111 until the speed ratio Ract of the transmission 115 reaches the target speed ratio Rtgt is larger is selected at any time. .

  In the second method described above, the generator 111 starts from the time when the rotational speed Ne of the internal combustion engine 109 decreases to the second threshold value th2, which is a stage before reaching the first threshold value th1. However, the zero torque control may be started from a point of time before the time when the rotational speed Ne is expected to reach the first threshold value th1.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

101 Battery (BATT)
103 Converter (CONV)
105 1st inverter (1st INV)
107 Electric motor (Mot)
109 Internal combustion engine (ENG)
111 Generator (GEN)
113 Second inverter (second INV)
115 Transmission (T / M)
117 Mechanical oil pump 119 Lock-up clutch 121 Engine temperature sensor 123 Speed sensor 124 Oil temperature sensor 125 Management ECU
127 Drive shaft 129 Drive wheel 151 Gear ratio control unit 153 Control method determination unit 155 Control torque calculation unit 157 Torque control unit

Claims (5)

An internal combustion engine;
A generator for generating electric power by the rotational power of the internal combustion engine;
An electric motor driven by power supply from at least one of a capacitor and the generator;
A power connection / disconnection mechanism for connecting / disconnecting a power transmission path from the internal combustion engine to the drive wheels;
A transmission for transmitting rotational power from the internal combustion engine to the drive wheels at a predetermined changeable gear ratio;
A mechanical oil pump that operates by rotational power from the internal combustion engine and provides the transmission with a hydraulic pressure for changing the transmission gear ratio;
A control device for a hybrid vehicle that travels by power from at least one of the electric motor and the internal combustion engine,
A torque control unit that controls the torque of the generator driven by inertial rotation of the internal combustion engine when driving of the internal combustion engine is stopped;
A gear ratio control unit that controls the gear ratio of the transmission to be a target gear ratio when driving of the internal combustion engine is stopped;
A control method determination unit that determines any of a plurality of methods as a control method by the torque control unit until the transmission of the internal combustion engine is stopped and the transmission gear ratio reaches the target gear ratio. And comprising
In the plurality of systems, the oil pump holds the oil pressure necessary to change the transmission gear ratio until the transmission gear ratio reaches the target gear ratio under the control of the gear ratio control unit. The torque of the generator is controlled so that the rotational speed of the internal combustion engine is maintained above a possible threshold value,
The hybrid vehicle control device in which the amount of regeneration by the generator differs until the transmission gear ratio reaches the target transmission gear ratio among the plurality of systems. The hybrid vehicle control device according to claim 1,
The control method determination unit includes the plurality of methods.
While the drive of the internal combustion engine is stopped and the transmission gear ratio shifts to the target transmission gear ratio, the transmission gear ratio is determined based on the rotational speed of the internal combustion engine and the transmission gear ratio. A hybrid vehicle control device that determines, as a control method by the torque control unit, a method in which the regeneration amount by the generator until the target speed ratio is reached is maximized. The hybrid vehicle control device according to claim 1 or 2,
The plurality of methods include
When the rotational speed of the internal combustion engine decreases to the threshold before the transmission gear ratio reaches the target gear ratio, the power generation by power supply from a capacitor charged with regenerative energy by the generator is performed. A first method of maintaining the rotational speed of the internal combustion engine at or above the threshold value by a driving torque of the machine;
If the rotational speed of the internal combustion engine decreases to the threshold before the transmission gear ratio reaches the target gear ratio, the transmission gear ratio before the target gear ratio is reached. A second method for controlling the generator torque to be substantially zero;
Contains
The control method determination unit is a hybrid vehicle control device that determines one of the first method and the second method as a control method by the torque control unit. A control device for a hybrid vehicle according to claim 3,
When the rotational speed of the internal combustion engine decreases to the threshold value when the torque control unit is controlling the torque of the generator based on the second method, the control method determining unit is configured to perform the first method. A hybrid vehicle control device that switches to A control device for a hybrid vehicle according to any one of claims 1 to 4,
The generator that acts as a load of the internal combustion engine while the rotational speed of the internal combustion engine is decreasing based on the rotational speed of the internal combustion engine and the transmission gear ratio, and the states of the internal combustion engine and the transmission The control apparatus of the hybrid vehicle provided with the control torque calculation part which calculates the torque of.

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