JP2010208541A - Control device of hybrid vehicle, control method, and hybrid vehicle - Google Patents

Abstract

In a hybrid vehicle, vibration during idle operation when a shift position is a neutral position is suppressed.
An ECU includes an engine, a rotating electrical machine, a rotating shaft of the rotating electrical machine, a power split mechanism connected to a rotating shaft of the engine and a driving shaft for driving wheels, an inverter for driving the rotating electrical machine, In a vehicle equipped with a shift lever for changing the travel range, the shift position detected by the step of detecting the shift position of the shift lever selected by the driver (S500) and the step of detecting the shift position is neutral. In response to the step of controlling the engine to stop when the position is changed (YES in S510) (S530), the shift position is changed to the neutral position, and the engine is stopped (YES in S540). To stop the generation of drive force by the rotating electrical machine. It executes a program including a step (S560) for controlling.
[Selection] Figure 5

Description

  The present invention relates to a control device, a control method, and a hybrid vehicle for a hybrid vehicle, and more particularly, to idle vibration prevention control for a hybrid vehicle.

  In a hybrid vehicle using an engine and a rotating electrical machine (motor generator) as power sources, for example, a planetary gear mechanism is mounted, the output shaft of the engine is mounted on the pinion gear, the rotating shaft of the first rotating electrical machine is mounted on the sun gear, and the ring gear is mounted. The rotation shafts of the second rotating electrical machines are coupled to each other via the drive shaft. By this planetary gear mechanism, the output of the engine is divided and transmitted to the drive shaft and the first rotating electrical machine. When starting the vehicle in a stopped state, the vehicle is started by rotating the drive shaft only with the second rotating electrical machine without using the driving force of the engine with poor output efficiency.

  In such a hybrid vehicle, when the shift position is set to the neutral position, the control command for the inverter that drives the rotating electrical machine is cut off in order to prevent unintended driving power of the rotating electrical machine from being transmitted to the drive wheels. There is a case.

  In Japanese Patent Application Laid-Open No. 2008-007045 (Patent Document 1), in the hybrid vehicle as described above, when the engine is driven with the shift position at the stop position (P position), the reverse position (R A technique is disclosed in which engine stop control is started after a predetermined time has elapsed since switching to the N position when operated in the order of position), neutral position (N position), and forward position (D position). .

  According to this technology, when switching from the P or R position to the D position through the N position, when the engine stop control is started and the engine torque is reduced, the torque of the rotating electrical machine is substantially zero. It is suppressed to be controlled. Therefore, the vibration of the gear due to the lower pressing force between the gear to which the output shaft of the engine is coupled and the gear to which the output shaft of the rotating electrical machine is coupled can be suppressed. Can be suppressed.

JP 2008-007045 A JP 2008-094178 A JP-A-10-174208 JP 2007-196757 A

  However, in the above-mentioned patent document 1, only the case where the P position is switched from the P or R position to the D position through the N position is targeted, and the shift position is switched from the P, R or D position to the N position. Is not considered. When the P or R position is switched to the N position, the torque of the rotating electrical machine is substantially zero when the engine is stopped after a predetermined time has elapsed. And the gear to which the output shaft of the rotating electrical machine is coupled, the noise may be generated due to a low pressing force.

  In the hybrid vehicle as described above, the torque of the rotating electrical machine is controlled to be substantially zero at the N position. Therefore, when the engine is stopped, cranking by the rotating electrical machine cannot be performed and the engine cannot be redriven. For this reason, when the engine is being driven at the time of switching the N position, there is a case where control is performed such that the driving state (so-called idle operation) is continued without stopping the engine. In this case, since the torque of the rotating electric machine is substantially zero, the electric power cannot be generated by the rotating electric machine and not only wasteful fuel consumption is caused, but also unnecessary vibrations caused by idle operation of the engine are given to the occupant. become.

  In general, it is known that when an engine has a low load, vibration during idling (idle vibration) becomes relatively large. Therefore, in the state where the torque of the rotating electrical machine is substantially zero and the load on the engine is low as described above, the idle vibration becomes relatively large.

  In particular, in the case of a system that does not have a torque converter between the engine and the drive shaft, the engine rotation fluctuations cannot be absorbed by the fluid in the torque converter, so that the engine is relatively idle compared to the system that has the torque converter. Vibration will increase.

  The present invention has been made to solve such a problem, and an object of the present invention is to suppress idling vibration when a shift position is a neutral position in a hybrid vehicle.

  A control apparatus for a hybrid vehicle according to the present invention includes an engine, a rotating electrical machine, a rotating shaft of the rotating electrical machine, a power split mechanism connected to a rotating shaft of the engine and a driving shaft for driving wheels, and a drive for driving the rotating electrical machine. A vehicle including an inverter and a shift lever for changing a travel range includes a shift detection unit, an engine control unit, and an inverter control unit. The shift detection unit is configured to detect the shift position of the shift lever selected by the driver. The engine control unit is configured to stop the engine when the shift position detected by the shift detection unit changes to the neutral position. Then, the inverter control unit controls the inverter so as to stop the generation of the driving force by the rotating electrical machine in response to the shift position changing to the neutral position and the engine being stopped.

  The hybrid vehicle control method according to the present invention drives an engine, a rotating electrical machine, a rotating shaft of the rotating electrical machine, a power split mechanism connected to a rotating shaft of the engine and a driving shaft for driving wheels, and the rotating electrical machine. In the vehicle provided with the inverter for changing, and the shift lever for changing a driving | running | working range, the step which detects a shift position, the step which controls an engine, and the step which controls an inverter are included. The step of detecting the shift position detects the shift position of the shift lever selected by the driver. The step of controlling the engine controls the engine to stop when the shift position detected by the step of detecting the shift position changes to the neutral position. The step of controlling the inverter controls the inverter to stop the generation of the driving force by the rotating electrical machine in response to the shift position changing to the neutral position and the engine being stopped.

  According to the control apparatus and control method for a hybrid vehicle described above, the engine can be stopped when the shift position changes to the neutral position, and the driving force from the rotating electrical machine is not output after the engine is stopped. Thereby, the idle operation of the engine is stopped when the shift position is the neutral position. Furthermore, the driving force of the rotating electrical machine is output until the engine is stopped, and the pressing force between the gears of the power split mechanism can be maintained even when the engine driving torque is reduced. The vibration of the gear of the split mechanism can be suppressed. As a result, it is possible to suppress idle vibration and abnormal noise that occur when the shift position is set to the neutral position. In addition, fuel consumption can be reduced by stopping the engine, so that fuel efficiency can be improved.

  Preferably, the inverter includes a switching element capable of switching between supply and interruption of electric power to the rotating electrical machine by a gate opening / closing command. And the inverter control part in the control apparatus of a hybrid vehicle controls so that the gate of a switching element may be interrupted | blocked according to a shift position changing to a neutral position and an engine stopping.

  The step of controlling the inverter in the hybrid vehicle control method performs control so that the gate of the switching element is cut off in response to the shift position changing to the neutral position and the engine being stopped.

  By adopting such a configuration, when the shift position becomes the neutral position and the engine is stopped, the gate of the switching element of the inverter is cut off, so that the generation of driving force by the rotating electrical machine can be stopped.

  Alternatively, preferably, the vehicle supplies power to the rotating electrical machine and is connected to the power storage device for storing the power generated by the rotating electrical machine and the power storage device and the inverter. And a power cut-off device configured to cut off input / output. The hybrid vehicle control device is configured to control the power shut-off device so as to shut off input / output of power between the power storage device and the inverter in response to the gate of the switching element being cut off. A shut-off control unit is further included.

  The hybrid vehicle control method further includes a step of shutting off input / output of power by the power cut-off device in response to the gate of the switching element being cut off.

  With such a configuration, when the shift position becomes the neutral position, the engine stops, and the gate of the switching element of the inverter is shut off, the power supply to the inverter can be cut off. In addition, the generation of driving force by the rotating electrical machine can be stopped.

  Preferably, the hybrid vehicle is equipped with the control device described above.

  According to the present invention, in the hybrid vehicle, idle vibration when the shift position is the neutral position can be suppressed.

It is a control block diagram of the whole hybrid vehicle including the control apparatus according to Embodiment 1 of the present invention. FIG. 4 is a diagram for explaining details of circuit configurations of an inverter and a converter in the first embodiment. It is a figure for demonstrating the detail of a power split device in this Embodiment 1. FIG. It is a functional block diagram which shows the control structure for demonstrating engine stop control in this Embodiment 1. FIG. 4 is a flowchart for illustrating details of engine stop control processing in the first embodiment. It is an example of the figure showing the relationship between engine rotational speed and the torque of motor generator MG1 during engine stop process execution. It is a control block diagram of the whole hybrid vehicle including the control apparatus according to Embodiment 2 of the present invention. It is a functional block diagram which shows the control structure for demonstrating engine stop control in this Embodiment 2. FIG. 12 is a flowchart for illustrating details of engine stop control processing in the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[Embodiment 1]
FIG. 1 shows a control block diagram of the entire hybrid vehicle including the control device according to the first embodiment of the present invention. The vehicle to which the control device according to the first embodiment can be applied is not limited to the hybrid vehicle shown in FIG. The control device according to the first embodiment has a hybrid having a mechanism in which a gear coupled to an output shaft of an internal combustion engine (hereinafter referred to as an engine) such as a gasoline engine meshes with a gear coupled to a rotation shaft of a motor generator. Applicable to any vehicle.

  Referring to FIG. 1, hybrid vehicle 100 includes a battery 220 as a power storage device, a converter 242, an inverter 240, motor generators MG1 and MG2 as rotating electric machines, an engine 120, a power split mechanism 200, and an output. Member 140, reduction gear 180, drive shaft 170, drive wheel 160, control device (hereinafter also referred to as ECU (Electronic Control Unit)) 300, shift lever 530, shift position sensor 540, and rotation sensor 500 Is provided. ECU 300 includes an HV-ECU 310 and an engine ECU 320.

  The battery 220 is a power storage element configured to be chargeable / dischargeable. The battery 220 includes a secondary battery such as a lithium ion battery or a nickel metal hydride battery, and a power storage element such as an electric double layer capacitor. Battery 220 is connected to converter 242, supplies DC power to inverter 240 that drives motor generators MG1 and MG2, and stores the electric power generated by motor generators MG1 and MG2.

  Further, battery 220 outputs to battery HV-ECU 310 voltage Vb, current Ib, and temperature Tb of battery 220 detected by a voltage sensor, current sensor, and temperature sensor (not shown).

  Converter 242 boosts DC power output from battery 220 to a voltage required by inverter 240 in accordance with drive command PWC output from HV-ECU 310. Further, converter 242 steps down the regenerative power from inverter 240 to a voltage that can be charged by battery 220 in accordance with drive command PWC output from HV-ECU 310.

  Inverter 240 is a generic description of inverters corresponding to motor generators MG1 and MG2, respectively. The inverter 240 converts the DC power boosted by converter 242 into AC power according to drive command PWI1 output from HV-ECU 310. And the motor generator MG1 is driven. Further, AC power is converted in accordance with drive command PWI2 output from HV-ECU 310, and motor generator MG2 is driven. Further, inverter 240 converts AC power generated by motor generators MG1 and MG2 into DC power and outputs the DC power to converter 242 as regenerative power.

The details of the circuit configuration of the inverter 240 and the converter 242 will be described with reference to FIG.
Referring to FIG. 2, hybrid vehicle 100 detects smoothing capacitor C1 connected between power supply line PL1 and ground line SL, and voltage VL between both ends of smoothing capacitor C1 in addition to the configuration of FIG. Voltage sensor 21 output to ECU 300, smoothing capacitor C2 that smoothes the voltage boosted by converter 242, and voltage sensor 13 that detects voltage VH between terminals of smoothing capacitor C2 and outputs the voltage to ECU 300 are included. Inverter 240 includes an inverter 14 for driving motor generator MG1 and an inverter 22 for driving motor generator MG2.

  Converter 242 includes a reactor L1 having one end connected to power supply line PL1, IGBT elements Q1 and Q2, which are power switching elements connected in series between power supply line PL2 and ground line SL, and IGBT elements Q1 and Q2. Includes diodes D1 and D2 connected in parallel.

  Reactor L1 has the other end connected to the emitter of IGBT element Q1 and the collector of IGBT element Q2. The cathode of diode D1 is connected to the collector of IGBT element Q1, and the anode of diode D1 is connected to the emitter of IGBT element Q1. The cathode of diode D2 is connected to the collector of IGBT element Q2, and the anode of diode D2 is connected to the emitter of IGBT element Q2.

  Inverter 14 receives the boosted voltage from converter 242, and drives motor generator MG1 to start engine 120, for example. Inverter 14 also outputs regenerative power generated by motor generator MG <b> 1 by mechanical power transmitted from engine 120 to converter 242. At this time, converter 242 is controlled by ECU 300 to operate as a step-down circuit.

  Inverter 14 includes a U-phase arm 15, a V-phase arm 16, and a W-phase arm 17. U-phase arm 15, V-phase arm 16, and W-phase arm 17 are connected in parallel between power supply line PL2 and ground line SL.

  U-phase arm 15 includes IGBT elements Q3 and Q4 connected in series between power supply line PL2 and ground line SL, and diodes D3 and D4 connected in parallel with IGBT elements Q3 and Q4, respectively. The cathode of diode D3 is connected to the collector of IGBT element Q3, and the anode of diode D3 is connected to the emitter of IGBT element Q3. The cathode of diode D4 is connected to the collector of IGBT element Q4, and the anode of diode D4 is connected to the emitter of IGBT element Q4.

  V-phase arm 16 includes IGBT elements Q5 and Q6 connected in series between power supply line PL2 and ground line SL, and diodes D5 and D6 connected in parallel with IGBT elements Q5 and Q6, respectively. The cathode of diode D5 is connected to the collector of IGBT element Q5, and the anode of diode D5 is connected to the emitter of IGBT element Q5. The cathode of diode D6 is connected to the collector of IGBT element Q6, and the anode of diode D6 is connected to the emitter of IGBT element Q6.

  W-phase arm 17 includes IGBT elements Q7 and Q8 connected in series between power supply line PL2 and ground line SL, and diodes D7 and D8 connected in parallel with IGBT elements Q7 and Q8, respectively. The cathode of diode D7 is connected to the collector of IGBT element Q7, and the anode of diode D7 is connected to the emitter of IGBT element Q7. The cathode of diode D8 is connected to the collector of IGBT element Q8, and the anode of diode D8 is connected to the emitter of IGBT element Q8.

  The motor generator MG1 is, for example, a three-phase AC motor generator including a rotor in which a permanent magnet is embedded and a stator having a three-phase coil Y-connected at a neutral point, and includes three U, V, and W phases. The coils are each connected at one end to a neutral point. The other end of the U-phase coil is connected to the connection node of IGBT elements Q3 and Q4. The other end of the V-phase coil is connected to a connection node of IGBT elements Q5 and Q6. The other end of the W-phase coil is connected to a connection node of IGBT elements Q7 and Q8.

  Inverter 14 converts the DC power supplied from converter 242 into desired AC power by turning on or off the gate signals of IGBT elements Q3 to Q8 in accordance with drive command PWI1 output from ECU 300. By turning off (blocking) all the gate signals, generation of the driving force of motor generator MG1 can be stopped.

  Hybrid vehicle 100 further includes an inverter 22 connected in parallel to inverter 14 with respect to converter 242.

  Inverter 22 converts the DC voltage output from converter 242 to three-phase AC and outputs the same to motor generator MG2 driving drive wheel 160. Inverter 22 also outputs regenerative power generated by motor generator MG2 to converter 242 in accordance with regenerative braking. At this time, converter 242 is controlled by ECU 300 to operate as a step-down circuit. Although the internal configuration of inverter 22 is not shown, it is similar to inverter 14, and detailed description will not be repeated.

  Referring to FIG. 1 again, motor generators MG1 and MG2 receive the AC power supplied from inverter 240 and generate a rotational driving force. Motor generators MG1 and MG2 receive AC rotational power from the outside and generate regenerative braking force on the vehicle according to a regenerative torque command from HV-ECU 310.

  Motor generators MG1 and MG2 are also coupled to engine 120 via power split mechanism 200. Control is executed by HV-ECU 310 such that the driving force generated by engine 120 and the driving force generated by motor generators MG1, MG2 have an optimal ratio. Alternatively, either one of motor generators MG1 and MG2 may function exclusively as an electric motor, and the other motor generator may function exclusively as a generator. In the first embodiment, it is assumed that motor generator MG1 functions as a generator driven by engine 120, and motor generator MG2 functions as an electric motor that drives drive wheels 160.

  In power split mechanism 200, a planetary gear mechanism (planetary gear) is used to distribute the power of engine 120 to both drive wheel 160 and motor generator MG1 via output member 140.

  The power split mechanism 200 will be further described with reference to FIG. Power split device 200 includes a planetary gear including a sun gear 202, a pinion gear 204, a carrier 206, and a ring gear 208.

  Pinion gear 204 is engaged with sun gear 202 and ring gear 208. The carrier 206 supports the pinion gear 204 so that it can rotate. Sun gear 202 is coupled to the rotation shaft of motor generator MG1. Carrier 206 is connected to a crankshaft (not shown) that is an output shaft of engine 120. Ring gear 208 is connected to the rotation shaft of motor generator MG 2 and reduction gear 180. Thus, when any two rotation directions and rotation speeds of engine 120, motor generator MG1 and motor generator MG2 are determined, the remaining rotation directions and rotation speeds are also forcibly determined.

  The driving force generated by engine 120 and motor generator MG2 is transmitted to driving wheel 160 via output member 140, reduction gear 180, and drive shaft 170.

  Referring again to FIG. 1, shift position sensor 540 detects the position of shift lever 530 and outputs signal POS representing the detection result to HV-ECU 310. The shift lever 530 includes a stop position (P position), a reverse position (R position), a neutral position (N position), and a forward position (D position).

  The rotation sensor 500 detects the rotation speed of the crankshaft that is the output shaft of the engine 120, and outputs the engine rotation speed NE that is a signal representing the detection result to the HV-ECU 310.

  HV-ECU 310 receives input of voltage Vb, current Ib, and temperature Tb from battery 220, and state quantities indicating the state of charge of the battery, for example, remaining capacity (also referred to as SOC (State of Charge)) and charge power upper limit Win. Etc. are calculated.

  HV-ECU 310 receives an engine rotation speed NE detected by rotation sensor 500 and a shift position signal POS representing the position of shift lever 530 detected by shift position sensor 540.

  Further, HV-ECU 310 generates a signal PWC for controlling converter 242 and outputs the signal to converter 242. Further, HV-ECU 310 generates signals PWI 1 and PWI 2 for driving inverter 240, and outputs the generated signals PWI 1 and PWI 2 to inverter 240. In addition, a signal for controlling engine 120 is transmitted to engine ECU 320.

  Although not shown, HV-ECU 310 and engine ECU 320 each include a CPU (Central Processing Unit), a storage device, and an input / output buffer, and perform input of each sensor and output of a control command to each device. At the same time, the hybrid vehicle 100 and each device are controlled. Note that these controls are not limited to software processing, and a part of them can be constructed and processed by dedicated hardware (electronic circuit).

  In FIG. 1, the HV-ECU 310 and the engine ECU 320 are configured as separate control devices. However, the configuration of the ECU is not limited to this, and as shown by a broken line in FIG. It may be configured. Further, some functions of the HV-ECU 310 may be further divided into separate control devices.

  In a hybrid vehicle equipped with a hybrid system as shown in FIG. 1, when a predetermined condition is established for the state of the vehicle, HV-ECU 310 causes motor generator MG2 and The engine 120 is controlled via the engine ECU 320. For example, the predetermined condition is a condition that the SOC of the battery 220 is equal to or greater than a predetermined value. In this way, the hybrid vehicle can be driven only by the motor generator MG2 when the engine 120 is inefficient at the time of starting or at low speed. As a result, the SOC of battery 220 can be reduced (battery 220 can be charged when the vehicle is subsequently stopped).

  Further, during normal traveling, for example, power split mechanism 200 divides the power of engine 120 into two paths, and on the other hand, driving wheels 160 are directly driven, and on the other hand, motor generator MG1 is driven to generate power. At this time, the motor generator MG1 is driven by the generated electric power to assist driving of the driving wheels 160. Further, during high speed traveling, electric power from battery 220 is further supplied to motor generator MG2 to increase the output of motor generator MG2 and drive force is added to drive wheels 160.

  On the other hand, at the time of deceleration, motor generator MG2 driven by drive wheel 160 functions as a generator to perform regenerative power generation, and the recovered regenerative power is stored in battery 220. When the amount of charge of battery 220 decreases and charging is particularly necessary, the output of engine 120 is increased to increase the amount of power generated by motor generator MG1 and the amount of charge for battery 220 is increased.

  Further, the target SOC of the battery 220 is normally set to about 60% so that regenerative energy can be recovered whenever regeneration is performed. Further, the upper limit value and the lower limit value of the SOC are set, for example, with the upper limit value set to 80% and the lower limit value set to 30% in order to suppress the deterioration of the battery of the battery 220. The HV-ECU 310 Motor generators MG1 and MG2 are controlled so as not to exceed the value and the lower limit. In addition, the value quoted here is an example and is not a particularly limited value.

  Further, HV-ECU 310 controls engine 120 and motor generators MG <b> 1 and MG <b> 2 as follows according to the position of shift lever 530.

  When shift lever 530 is in the P position, HV-ECU 310 normally stops engine 120 and motor generators MG1 and MG2. However, when the SOC of battery 220 is lower than the lower limit value, HV-ECU 310 drives engine 120 even in the P position. Motor generator MG1 generates electric power using the power of engine 120 transmitted to motor generator MG1 through power split mechanism 200. The generated electric power is charged in the battery 220.

  When shift lever 530 is in the R position, HV-ECU 310 drives motor generator MG2 so that the hybrid vehicle is moved backward only by the output of motor generator MG2.

  When shift lever 530 is in the D position, HV-ECU 310 drives engine or / and motor generator MG2 to cause the hybrid vehicle to travel forward.

  When shift lever 530 is in the N position, HV-ECU 310 performs control so that generation of driving force by motor generators MG1 and MG2 is stopped in order to set the driving force of the hybrid vehicle to a neutral state.

  In a hybrid vehicle that performs such control, if the engine 120 is stopped when the shift lever 530 is at the N position, the driving force cannot be output from the motor generator MG1, and the engine 120 is restarted due to cranking. Since the engine cannot be driven, when the engine 120 is in a driving state and the position of the shift lever 530 becomes the N position, there is a case where control for continuing driving of the engine 120 is employed. In such a case, vibration (idle vibration) due to idling operation of the stopped engine 120 occurs.

  In addition, when an automatic transmission is adopted as a speed change mechanism in a vehicle equipped only with an engine, a torque converter, which is a power transmission mechanism using fluid, is used. Oil). However, in the hybrid vehicle as shown in FIG. 1, since a power split mechanism using gears is adopted as a speed change mechanism, there are few portions that absorb idle vibration, and compared with a case where an automatic transmission having a torque converter is adopted. The structure is easy to transmit idle vibration.

  In the hybrid vehicle as described above, in the case of the P position where the driving force of the motor generator MG1 can be output, for example, the motor generator MG1 is controlled by driving the motor generator MG1 with a reverse phase torque that cancels idle vibration. By performing vibration control, it is possible to suppress the occurrence of idle vibration. However, at the N position, since the driving force of motor generator MG1 is interrupted as described above, it is difficult to perform such vibration suppression control, so that idle vibration is likely to occur.

  In recent years, high-end vehicles are also equipped with a hybrid system, and the demand for quietness is increasing. Therefore, it is desirable to further suppress idle vibration in the hybrid vehicle.

  Further, at the N position, since the torque of motor generator MG1 is cut off as described above, even if engine 120 is operated, motor generator MG1 cannot generate power, and fuel is wasted. For this reason, it is desirable to stop the idling operation at the N position from the viewpoint of improving fuel efficiency by reducing fuel consumption and protecting the environment.

  Therefore, in the first embodiment, when the shift position is switched to the neutral position, the engine stop is preceded, and the engine stop that shuts off the control commands of motor generators MG1 and MG2 after the engine 120 is stopped. Take control. This engine stop control suppresses idle vibration and reduces fuel consumption.

  FIG. 4 is a functional block diagram showing a control configuration of ECU 300 for explaining the engine stop control in the first embodiment. Each functional block described in the functional block diagram illustrated in FIG. 4 and FIG. 8 described later is realized by hardware or software processing by the ECU 300.

  Referring to FIG. 4, HV-ECU 310 of ECU 300 includes a shift detection unit 400, an engine control unit 410, and an inverter control unit 420.

  The shift detection unit 400 receives a shift position signal POS indicating the shift position from the shift position sensor 540, and detects whether or not the shift position has been switched to the N position. When it is detected that the position has been switched to the N position, the neutral position flag NPFLG indicating that the position is the N position is turned on and output to the engine control unit 410 and the inverter control unit 420.

  At this time, the determination as to whether or not the position has been switched to the N position is made by determining that the shift lever 530 is continuously set to the N position for a predetermined time (for example, 1 second) or longer. This prevents the engine stop control from being executed at unnecessary timing by instantaneously detecting the N position when passing through the N position and switching to another shift position. It is to do.

  Engine control unit 410 receives an input of neutral position flag NPFLG from shift detection unit 400. When it is detected that the neutral position flag NPFLG is on, that is, when the neutral position flag NPFLG is switched to the neutral position, the engine control unit 410 turns on the engine stop signal ESTP and outputs it to the engine ECU 320. In response to this engine stop signal ESTP, engine ECU 320 performs stop control of engine 120 such as stopping fuel injection and stopping ignition in the cylinder.

  Inverter control unit 420 receives input of engine speed NE detected by rotation sensor 500 and neutral position flag NPFLG from shift detection unit 400. Then, when it is detected that the shift position is switched to the N position and engine 120 is stopped, inverter control unit 420 is configured so that the driving force of motor generators MG1 and MG2 is interrupted (that is, inverter 240 Drive commands PWI1 and PWI2 for the inverter 240 are generated and output to the inverter 240 (so that the gate of the switching element is cut off).

  By controlling in this way, idling vibration of the engine 120 can be suppressed by stopping the engine 120 by switching to the N position. Further, by continuing to output the torque of motor generators MG1 and MG2 until engine 120 is stopped, it is possible to prevent a reduction in the pressing force of the gear in power split mechanism 200 when the engine torque is reduced. Can be suppressed.

  FIG. 5 shows a flowchart for explaining details of processing of engine stop control by ECU 300. The flowchart shown in FIG. 5 and FIG. 9 described below is realized by executing a program stored in advance in ECU 300 at a predetermined cycle. Alternatively, for some steps, it is also possible to construct dedicated hardware (electronic circuit) and realize processing.

  Referring to FIG. 5, ECU 300 detects the current shift position based on shift position signal POS from shift position sensor 540 at step (hereinafter, step is abbreviated as S) 500.

  Next, in S510, ECU 300 determines whether or not the shift position has changed from other than N position to N position.

  If the shift position has changed to the N position (YES in S510), it is next determined in S520 whether engine 120 is in operation. Specifically, determination is made based on whether or not the engine rotation speed NE detected by the rotation sensor 500 is lower than a predetermined reference rotation speed.

  If engine 120 is operating (YES in S520), ECU 300 executes an engine stop process in S530. Specifically, the fuel injection to the engine 120 is stopped, and the ignition control is stopped when the ignition to the already injected fuel is completed. Then, until the engine 120 is stopped (that is, until the engine rotational speed NE becomes equal to or lower than a predetermined reference value), it is repeatedly determined whether or not the engine 120 is stopped (S540), and it is detected that the engine 120 has stopped. If so (YES in S540), the process proceeds to S550.

  At this time, as shown in FIG. 6, with the engine stop process, torque that decreases the engine rotation speed is applied to motor generator MG1. As a result, the engine rotation speed NE can quickly pass through the mechanical resonance rotation speed of the engine 120 to shorten the engine stop time.

  On the other hand, if engine 120 is not in operation at S520 (NO at S520), the engine stop process from S530 to S540 is skipped and the process proceeds to 550.

  In S550, ECU 300 determines the neutral range (N range) when the shift position is switched to the N position and engine 120 is stopped.

  Then, in S560, ECU 300 generates drive commands PWI1, PWI2 so as to stop (shut off) the generation of the driving force from motor generators MG1, MG2. Then, the drive commands PWI1 and PWI2 are output to the inverter 240, and the inverter 240 is stopped. Thereafter, the process is returned to the main routine.

  If the shift position has not changed to the N position (NO in S510), the processes from S520 to S560 are not performed, and the process returns to the main routine.

  By performing the processing according to the flowchart as described above, it is possible to suppress idle vibration by the engine 120 at the N position. Furthermore, fuel consumption can be reduced by stopping the engine, so that fuel consumption can be improved.

[Embodiment 2]
In the second embodiment, in addition to the first embodiment, by providing a power cutoff device for cutting off power between battery 220 and converter 242, when the shift position is the N position, the motor generator Control for reliably stopping generation of driving force from MG1 and MG2 will be described.

  FIG. 7 shows a control block diagram of the entire hybrid vehicle including the control device according to the second embodiment of the present invention. 7 has a configuration in which a system relay (hereinafter also referred to as SMR) 222, which is a power interrupt device for interrupting power, is added between the battery 220 and the converter 242 in FIG. In the following description, the description of the same part as in FIG. 1 will not be repeated.

  Referring to FIG. 7, SMR 222 is provided between battery 220 and converter 242, and is connected to battery 220 and converter 242. Then, the SMR 222 switches the power cutoff or transmission according to the cutoff signal SD from the HV-ECU 310. When the cutoff signal SD is on, the contact of the SMR 222 is opened so that the power is cut off. On the other hand, when the cut-off signal SD is off, the contact of the SMR 222 is closed so that power can be input and output.

  FIG. 8 is a functional block diagram showing a control configuration of ECU 300 for explaining the engine stop control in the second embodiment. FIG. 8 is obtained by adding a blocking control unit 430 to the functional block diagram of FIG. 4 in the first embodiment. In the following description, the description of the same part as in FIG. 4 will not be repeated.

  Inverter control unit 420 outputs PWI1 and PWI2 to inverter 240 so that generation of driving force from motor generators MG1 and MG2 is stopped (that is, so as to shut off the gate of the switching element), A gate cutoff signal GS indicating that the gate cutoff has been performed is output to the cutoff control unit 430.

  The cutoff control unit 430 receives the neutral position flag NPFLG from the shift detection unit, the gate cutoff signal GS from the inverter control unit 420, and the engine rotational speed NE from the rotation sensor 500. Then, when detecting that the shift position is switched to the N position, the engine is stopped, and the control command of the inverter 240 is shut off, the shutoff control unit 430 turns on the shutoff signal SD for shutting down the SMR 222. Output to SMR 222.

  FIG. 9 shows a flowchart for explaining details of the engine stop control process by ECU 300 in the second embodiment. FIG. 9 is obtained by adding step S570 to the flowchart of FIG. 5 in the first embodiment. In the following description, the description of the same part as in FIG. 5 will not be repeated.

  In S560, ECU 300 generates drive commands PWI1, PWI2 for inverter 240 so as to stop (shut off) the generation of driving force from motor generators MG1, MG2, and outputs drive commands PWI1, PWI2 to inverter 240. To do. Then, the process proceeds to S570, and ECU 300 outputs a cutoff command SD to SMR 222 in order to cut off the discharge from battery 220.

  Thereby, the contact of SMR 222 is opened, and the supply of power from battery 220 to converter 242 is stopped.

  Although not shown, when the shift position is switched to a position other than the N position, the cutoff signal SD is turned off and the contact of the SMR 222 is closed.

  By performing control according to the above-described processing, it is possible to reliably cut off the generation of driving force from motor generators MG1 and MG2 when the shift position is set to the N position.

  In addition, about the functional block diagram and flowchart mentioned above, it is not essential to provide all the functional blocks and steps described, and it is possible to omit some functional blocks and steps as necessary. Let me make sure.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  13, 21 Voltage sensor, 14, 22, 240 Inverter, 15 U-phase arm, 16 V-phase arm, 17 W-phase arm, 100 Hybrid vehicle, 120 Engine, 140 Output member, 160 Drive wheel, 170 Drive shaft, 180 Reducer , 200 power split mechanism, 202 sun gear, 204 pinion gear, 206 carrier, 208 ring gear, 220 battery, 222 system relay, 242 converter, 300 ECU, 310 HV-ECU, 320 engine ECU, 400 shift detection unit, 410 engine control unit, 420 inverter control unit, 430 shut-off control unit, 500 rotation sensor, 530 shift lever, 540 shift position sensor, C1, C2 smoothing capacitor, D1-D8 diode, L1 reactor , MG1, MG2 motor generator, PL1, PL2 power line, SL ground line.

Claims (7)

A control device for a hybrid vehicle,
The vehicle is
Engine,
Rotating electrical machinery,
A power split mechanism connected to a rotating shaft of the rotating electrical machine, a rotating shaft of the engine and a driving shaft for driving wheels;
An inverter for driving the rotating electrical machine;
With a shift lever for changing the driving range,
The control device includes:
A shift detector configured to detect a shift position of the shift lever selected by the driver;
An engine control unit (410) configured to stop the engine when the shift position detected by the shift detection unit changes to a neutral position;
A hybrid including an inverter control unit for controlling the inverter to stop generating the driving force by the rotating electrical machine in response to the shift position changing to the neutral position and the engine being stopped. Vehicle control device. The inverter is
Including a switching element capable of switching between supply and interruption of power to the rotating electrical machine according to a gate opening / closing command,
2. The hybrid vehicle according to claim 1, wherein the inverter control unit controls the gate of the switching element to be shut off in response to the shift position changing to the neutral position and the engine being stopped. Control device. The vehicle is
A power storage device for supplying power to the rotating electrical machine and storing the power generated by the rotating electrical machine;
A power shut-off device connected to the power storage device and the inverter, and configured to cut off power input / output between the power storage device and the inverter;
The control device includes:
The power supply device further includes a shut-off control unit that controls the power shut-off device to shut off input / output of power between the power storage device and the inverter in response to the gate of the switching element being shut off. The hybrid vehicle control device according to 2.   The hybrid vehicle carrying the hybrid vehicle control apparatus of any one of Claims 1-3. A control method for a hybrid vehicle,
The vehicle is
Engine,
Rotating electrical machinery,
A power split mechanism connected to a rotating shaft of the rotating electrical machine, a rotating shaft of the engine and a driving shaft for driving wheels;
An inverter for driving the rotating electrical machine;
With a shift lever for changing the driving range,
The control method is:
Detecting a shift position of the shift lever selected by the driver;
Controlling the engine to stop the engine when the shift position changes to a neutral position;
Controlling the inverter to stop generating the driving force by the rotating electrical machine in response to the shift position changing to the neutral position and the engine being stopped. . The inverter is
Including a switching element capable of switching between supply and interruption of power to the rotating electrical machine according to a gate opening / closing command,
The step of controlling the inverter is controlled to shut off the gate of the switching element in response to the shift position changing to the neutral position and the engine being stopped. Control method of hybrid vehicle. The vehicle is
A power storage device for supplying power to the rotating electrical machine and storing the power generated by the rotating electrical machine, and provided between the rotating electrical machine and the power storage device, between the power storage device and the rotating electrical machine And a power cut-off device configured to cut off the power input / output of
The control method is:
The hybrid vehicle control method according to claim 6, further comprising a step of interrupting power input / output by the power interrupt device in response to the gate of the switching element being interrupted.

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