JP2016117353A - Hybrid vehicle - Google Patents

Abstract

In a hybrid vehicle, comfort at the time of stopping during engine load operation is improved.
A hybrid vehicle includes an engine connected to a drive shaft, a motor generator connected to the drive shaft via a counter gear, and an ECU for controlling the motor generator. The ECU is configured to correct the output torque of the motor generator so as to cancel the torque fluctuation accompanying the stop of the engine when the engine is stopped from the state where the engine and the motor generator are driven. The ECU reduces the correction amount based on the correction amount of the output torque and the output torque of the motor generator before correction. The ECU sets the correction amount to be reduced as the output torque correction amount increases.
[Selection] Figure 1

Description

  The present invention relates to a hybrid vehicle including an internal combustion engine and a rotating electrical machine, and more particularly to control for improving comfort when the internal combustion engine is stopped in the hybrid vehicle.

  A hybrid vehicle that travels using driving force from an engine and a rotating electrical machine (motor generator) is known.

  In such a vehicle, when the vehicle is running using the driving force from the motor generator together with the driving force from the motor generator, a Ready-OFF state is caused by a user's erroneous operation or an abnormality occurs in the engine. The engine may be stopped.

  In Japanese Patent No. 0442335 (Patent Document 1), when such a transient torque fluctuation (decrease) occurs due to engine stop, the torque fluctuation of the motor generator is temporarily increased to cancel the torque fluctuation. A technique for suppressing the deterioration of drivability is disclosed.

Patent No. 0442335 JP 2012-153111 A JP 2000-115911 A JP-A-11-336581

  On the other hand, when the motor generator torque is temporarily increased as described above when the output torque of the motor generator is negative, the output torque of the motor generator may be substantially zero.

  Then, in the gear in the power transmission path from the motor generator to the driving wheel, the pressing force of the tooth surface decreases, and the gear is in a floating state (floating). (Hereinafter also referred to as “tooth rattling sound”) may occur. Such a rattling sound is recognized as noise by the driving user, and thus the comfort may be impaired.

  The present invention has been made to solve such a problem, and an object of the present invention is to improve the comfort of a hybrid vehicle when the engine is stopped during load operation.

  A hybrid vehicle according to the present invention includes an internal combustion engine (engine) coupled to a drive shaft, a rotating electrical machine (motor generator) coupled to the drive shaft via a counter gear, and a control device for controlling the rotating electrical machine. Prepare. The control device corrects the output torque of the rotating electrical machine so as to cancel the torque fluctuation of the rotating electrical machine accompanying the stop of the internal combustion engine when the internal combustion engine is stopped from the state where the internal combustion engine and the rotating electrical machine are driven. Composed. The control device reduces the correction amount based on the correction amount of the output torque and the output torque of the rotating electrical machine before correction. Then, the control device sets the reduction amount of the correction amount to increase as the correction amount increases.

  The torque correction amount of the motor generator for suppressing the torque fluctuation accompanying the engine stop needs to be set larger as the engine output torque before the engine stop is larger. On the other hand, when the output torque of the motor generator before the engine stops is negative, if the above torque correction amount increases, the output torque of the motor generator tends to approach zero, and as a result, rattling noise is likely to occur. For this reason, it is preferable to make the torque correction amount as small as possible from the viewpoint of suppressing the rattling noise. Thus, suppression of torque fluctuation due to engine stop and suppression of generation of rattling noise are in a trade-off relationship with each other. By adopting the configuration as in the present invention, it is possible to moderately reduce torque fluctuations caused by stopping the engine by increasing the output torque of the motor generator and to suppress the occurrence of rattling noise that can be caused by torque correction of the motor generator. It is possible to achieve both.

  ADVANTAGE OF THE INVENTION According to this invention, in the hybrid vehicle, the comfort at the time of the stop in the load operation of an engine can be improved.

1 is a skeleton diagram of a hybrid vehicle according to a first embodiment. FIG. It is a time chart for demonstrating torque correction at the time of an engine stop. It is a figure for demonstrating generation | occurrence | production of the rattling sound by torque correction. It is a figure which shows the relationship between a torque correction factor and a rattling sound. It is a figure for demonstrating the driving force of 2nd MG in case the accelerator pedal operation amount is 0%. It is a figure for demonstrating the relationship between the initial output torque of 2nd MG, and correction of torque correction amount. 4 is a flowchart for illustrating torque correction control executed by an ECU in the first embodiment. FIG. 6 is a skeleton diagram of a hybrid vehicle according to a second embodiment. It is a figure which shows the operation engagement table | surface of the clutch C1 and brake B1 which are included in a transmission. It is an alignment chart in the HV traveling mode when the transmission is on the Lo side. It is an alignment chart in the HV running mode when the transmission is on the Hi side. In Embodiment 2, it is a flowchart for demonstrating the torque correction control performed by ECU. It is a figure for demonstrating the parameter correction of the other gear stage in step S160A.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
(Basic configuration of vehicle)
FIG. 1 is a skeleton diagram showing an overall configuration of a vehicle 1 on which a drive device according to the first embodiment is mounted. The drive device of the vehicle 1 includes an engine 10, a first motor generator (hereinafter referred to as “first MG”) 20, a second motor generator (hereinafter referred to as “second MG”) 30, a first MG, and a second MG. Inverters 25 and 35 for driving, a power distribution device (planetary gear device) 50, a counter shaft (output shaft) 70, a differential device 80, drive wheels 90, and an ECU (Electronic Control Unit) 300 are provided. Including.

  The vehicle 1 is an FF (front engine / front drive) type hybrid vehicle that travels using at least one of the power of the engine 10, the first MG 20, and the second MG 30. The driving method of the vehicle 1 is not limited to the FF method, and may be an FR (front engine / rear drive) method. The vehicle 1 may be a plug-in hybrid vehicle that can charge an in-vehicle battery (not shown) with an external power source.

  The engine 10 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine. Engine 10 is controlled by a control signal DRV from ECU 300.

  The first MG 20 and the second MG 30 are, for example, permanent magnet type synchronous motors including a rotor in which permanent magnets are embedded. The rotation shaft 21 of the first MG 20 is disposed coaxially with the crankshaft of the engine 10. The rotation shaft 31 of the second MG 30 is arranged in parallel with the rotation shaft 21 of the first MG 20. The counter shaft (output shaft) 70 is arranged in parallel with the rotation shaft 21 of the first MG 20 and the rotation shaft 31 of the second MG 30.

  First MG 20 and second MG 30 are driven by inverters 25 and 35, respectively. The inverter 25 is controlled by a control signal PWI1 from the ECU 300, converts DC power from a vehicle battery (not shown) into AC power, and supplies the AC power to the first MG 20. Similarly, inverter 35 is controlled by control signal PWI2 from ECU 300, converts DC power from the battery into AC power, and supplies the AC power to second MG 30. The second MG 30 is also driven by the electric power generated by the first MG 20.

  The power distribution device 50 includes a single pinion type planetary gear mechanism including a sun gear S2, a pinion gear P2, a ring gear R2, and a planetary carrier CA2 (hereinafter also simply referred to as “carrier”). Carrier CA <b> 2 of power distribution device 50 is coupled to the output shaft of engine 10.

  Pinion gear P2 is arranged between sun gear S2 and ring gear R2, and meshes with sun gear S2 and ring gear R2, respectively. Pinion gear P2 is supported by carrier CA2 so as to be capable of rotating and revolving.

  Sun gear S2 is coupled to rotating shaft 21 of first MG 20. A counter drive gear 51 is connected to the ring gear R2. The counter drive gear 51 is an output gear of the power distribution device 50 that rotates integrally with the ring gear R2.

  The rotational speed of the sun gear S2 (that is, the rotational speed of the first MG 20), the rotational speed of the carrier CA2, and the rotational speed of the ring gear R2 are connected in a straight line on the nomograph (that is, if any two rotational speeds are determined) The rotation speed is also determined). Therefore, by adjusting the rotation speed of the first MG 20, the ratio between the rotation speed of the carrier CA2 and the ring gear R2 can be switched steplessly.

  The counter shaft (output shaft) 70 is provided with a counter driven gear 71 and a differential drive gear 72. Counter driven gear 71 meshes with counter drive gear 51 of power distribution device 50. That is, the power of the engine 10 and the first MG 20 is transmitted to the counter shaft (output shaft) 70 via the counter drive gear 51 of the power distribution device 50.

  That is, the rotation of the engine 10 is transmitted to the counter shaft (output shaft) 70 after being shifted in the power distribution device 50.

  Counter driven gear 71 also meshes with reduction gear 32 connected to rotating shaft 31 of second MG 30. That is, the power of the second MG 30 is transmitted to the counter shaft (output shaft) 70 via the reduction gear 32.

  The differential drive gear 72 meshes with the differential ring gear 81 of the differential device 80. The differential device 80 is connected to the left and right drive wheels 90 via left and right drive shafts 82, respectively. That is, the rotation of the counter shaft (output shaft) 70 is transmitted to the left and right drive shafts 82 via the differential device 80.

  ECU 300 includes a CPU (Central Processing Unit), a storage device, and an input / output buffer, all of which are not shown in FIG. 1, and inputs signals from sensors and the like and outputs control signals to each device. 1 and each device are controlled. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  In the hybrid vehicle having such a configuration, when the engine 10 is in a load operation in which at least a part of the driving force is used as the driving force of the driving wheel 90, for example, the ignition switch is turned off by a user's erroneous operation, Alternatively, when a failure occurs in the engine 10, it is necessary to stop the engine 10 immediately. In this case, since the engine 10 is in a load operation until the fuel cut (F / C) is received after receiving the stop instruction, the driving force (torque) transmitted to the drive wheels 90 is suddenly increased when the engine 10 is stopped. To drop. Thereby, the user during driving may feel torque fluctuation (torque shock).

  In order to suppress such torque fluctuation, it is conceivable to increase the output torque of the second MG 30 so as to cancel the decrease in the output torque of the engine 10.

  FIG. 2 shows an outline of such torque correction control. In FIG. 2, when the engine 10 under load operation is stopped at time t1, the torque of the second MG 30 (MG2) is temporarily increased stepwise correspondingly.

  On the other hand, depending on the running state of the vehicle (particularly the state where the output torque of the second MG 30 is negative), when the torque of the second MG 30 is increased as the engine 10 stops, the output torque of the second MG 30 results in a value close to zero. It may become.

  Then, the pressing force of the tooth surface between the reduction gear 32 of the rotating shaft 31 of the second MG 30 and the counter driven gear 71 is reduced, so that the gear is in a floating state, and the tooth surface is contacted again. There is a possibility that a rattling sound will be generated in the lower part of FIG. Such a rattling sound is perceived as noise by the user during driving, and thus may deteriorate comfort.

  In order to reduce the torque shock accompanying the stop of the engine 10, it is effective to correct the torque of the second MG 30 so as to increase, but from the viewpoint of reducing the rattling noise, the amount of increase in torque is reduced. Need to be traded off.

  Therefore, in the first embodiment, torque correction control is executed so that both reduction of torque shock and suppression of rattling noise can be appropriately realized.

  FIG. 3 is a diagram for explaining the reason why the rattling noise is generated in the torque correction control for reducing the torque shock and the torque correction control in the present embodiment in more detail. FIG. 3 is an enlarged view of the torque of the second MG 30 near time t1 in FIG.

  Referring to FIG. 3, when second MG 30, which output negative torque before engine stop, increases torque stepwise as engine 10 stops, the total torque of second MG 30 becomes negative due to the increased torque. Has become positive. In this case, at the points P1 and P2 where the sign of the torque changes, the pressing direction of the tooth surface between the reduction gear 32 of the second MG 30 and the counter driven gear 71 is reversed, so that the opposite side is caused by gear backlash. The tooth surface comes into contact with each other, and a rattling sound is generated.

  This step-like torque correction amount is basically determined according to the torque fluctuation of the engine 10, but this correction amount is reduced as shown by the broken line in FIG. 3 so that the sign of the torque does not change. Then, although the influence of the torque fluctuation due to the engine stop remains somewhat, the occurrence of rattling noise can be suppressed.

  FIG. 4 is a diagram showing an example of a relationship between a torque correction amount reduction rate (hereinafter also referred to as “correction rate”) and noise generated in the power transmission system. Here, the “correction rate” is given as a numerical value from 0 to 1. Correction rate = 1 indicates that the amount of decrease from the torque correction amount is zero, that is, the original torque correction amount remains the same, and correction rate = 0 indicates that the torque correction amount is zero.

  As can be seen from FIG. 4, the noise becomes smaller as the correction factor approaches zero, that is, as the distance DS from the zero Nm line of the final second MG 30 torque increases. In other words, it can be seen that the closer the torque of the second MG 30 is to the zero Nm line, the greater the noise due to the generation of rattling noise. Therefore, from the viewpoint of noise, it is more preferable to make the correction factor close to zero, but setting the correction factor to zero means that no torque is generated that cancels the torque fluctuation caused by the engine stop. The correction factor needs to be an intermediate value between 0 and 1 (for example, 0.2 to 0.7).

  However, such correction of the torque correction amount by considering the rattling noise is not always effective, and varies depending on the state of the output torque of the second MG 30 before the engine is stopped.

  FIG. 5 is a diagram showing the relationship between the vehicle speed and the output torque of the second MG 30 when the accelerator pedal is not depressed. Referring to FIG. 5, when the vehicle speed is relatively low, second MG 30 outputs a positive torque to generate a so-called creep torque, and when the vehicle speed increases, to generate engine brakes in a simulated manner. It is set to output negative torque. Although not shown in FIG. 5, when the vehicle speed is zero (that is, when the vehicle is stopped), the reaction force of the engine 10 is received by the second MG 30, so the torque of the second MG 30 is a negative torque. . Thus, the initial torque of the second MG 30 before performing the torque correction control varies depending on the vehicle speed.

  FIG. 6 is a diagram for explaining the effect of the torque correction control of the present embodiment using the initial torque of the second MG 30. In FIG. 6, (a) in the upper stage shows a case where the initial torque as shown in FIG. 3 is relatively large in the negative direction, that is, a case where the vehicle speed is relatively high. In this case, since the corrected torque becomes close to zero Nm by the torque correction amount that cancels the torque fluctuation, the effect of reducing the rattling noise is exhibited by reducing the torque correction amount.

  On the other hand, when the initial torque of the second MG 30 is relatively small in the negative direction ((b) of FIG. 6), in order to suppress the rattling noise, the reduction amount of the torque correction amount is increased (that is, the correction rate is increased). It is necessary to be small), and the influence of torque fluctuation due to the engine stop is rather large. Therefore, in such a case, priority is given to the reduction of the torque fluctuation accompanying engine stop, permitting generation | occurrence | production of a rattling sound.

  In addition, when the initial torque is positive at a low vehicle speed ((c) in FIG. 6), the torque is always positive even if a torque correction amount that cancels the torque fluctuation is added. Does not occur. Therefore, in such a case, it is preferable that the correction rate is 1 without reducing the torque correction amount.

  As described above, the torque correction amount reduction amount (that is, the correction rate) is set based on the state of the output torque of the second MG 30 and the engine 10 before the engine is stopped.

  FIG. 7 is a flowchart for illustrating torque correction control executed by ECU 300 in the first embodiment. The flowchart shown in FIG. 7 and FIG. 12 described later is realized by calling and executing a program stored in the ECU 300 in advance when a predetermined cycle or a predetermined condition is satisfied. Alternatively, for some steps, it is also possible to construct dedicated hardware (electronic circuit) and realize processing.

  Referring to FIG. 7, ECU 300 determines in step (hereinafter, step is abbreviated as S) 100 whether the current output torque of second MG 30 is relatively large in the negative direction. Specifically, it is determined whether or not the torque of the second MG 30 is smaller than a predetermined value α (<0). If the torque of second MG 30 is smaller than predetermined value α (YES in S100), ECU 300 proceeds to S110 assuming that there is an effect of suppressing rattling noise.

  On the other hand, if the torque of second MG 30 is equal to or greater than predetermined value α (NO in S100), ECU 300 determines that there is no effect of suppressing the rattling sound and skips the subsequent processes for suppressing the rattling sound and ends the process. To do. In this case, a torque correction amount (that is, correction rate = 1) corresponding to the engine output torque before the engine is stopped is used.

  In S110, ECU 300 determines whether engine 10 is currently in a load operation. ECU 300 advances the process to S120 when engine 10 is under load operation (YES at S110), and ends the process when engine 10 is not under load operation (NO at S110).

  Next, ECU 300 determines in S120 whether or not an engine stop instruction has been issued. ECU 300 advances the process to S130 when an engine stop instruction is issued (YES at S120), and ends the process when an engine stop instruction is not issued (NO at S120).

  When an engine stop instruction is issued, ECU 300 sets a torque correction amount of second MG 30 for canceling the torque fluctuation associated with the engine stop based on the current (before the engine stop) engine output torque in S130. This torque correction amount is basically set to be larger as the engine output torque before the engine stops is larger.

  In addition, as described with reference to FIG. 6, ECU 300 suppresses rattling noise in consideration of the current output torque of second MG 30 and the torque correction amount of second MG 30 for canceling the torque fluctuation caused by the engine stop. To set the torque correction factor. The torque correction rate is basically set so that the reduction amount of the correction amount increases as the torque correction amount of the second MG 30 increases.

  Then, ECU 300 calculates the final torque correction amount by multiplying the correction amount and the correction rate.

  Thereafter, in S140, ECU 300 executes an engine stop process using the correction amount calculated in S130. At this time, when the influence of the torque fluctuation is large, the rapid torque fluctuation may be alleviated by limiting the throttle opening amount when the engine is stopped.

  While the engine stop process is being executed, ECU 300 evaluates actual behavior (torque shock) and rattling sound of vehicle 1 from the rotational speed (angular acceleration) and torque fluctuation of second MG 30 (S150). In step S160, ECU 300 updates the control parameters such as the correction rate and the throttle opening amount based on these evaluations, and performs learning control.

  By performing the control according to the above processing, in a hybrid vehicle, when it is necessary to stop the engine quickly during engine load operation, torque fluctuations due to engine stop and reduction of rattling noise are reduced. Considering both, the optimal correction amount of the output torque of the second MG 30 can be determined. As a result, both torque shock and noise can be moderately suppressed, and comfort for the user during driving can be improved.

[Embodiment 2]
In the first embodiment, the case where the torque correction control in the present application is applied to the configuration in which the output shaft of the engine is directly connected to the carrier of the power distribution device has been described.

  In the second embodiment, a case will be described in which torque correction control is applied to a hybrid vehicle having a configuration in which a transmission is provided between an engine and a power distribution device.

  In the hybrid vehicle 1A of FIG. 8, a transmission 40 is provided between the engine 10 and the power distribution device 50 of the hybrid vehicle 1 shown in FIG. 1, and a clutch and a brake (described later) included in the transmission 40 are provided. A hydraulic device for driving is added. In the following description of FIG. 8, description of elements overlapping with FIG. 1 will not be repeated.

  Referring to FIG. 8, transmission 40 is provided between engine 10 and power distribution device 50, changes the rotation of engine 10, and outputs it to power distribution device 50. The transmission 40 includes a single pinion planetary gear mechanism including a sun gear S1, a pinion gear P1, a ring gear R1, and a planetary carrier CA1, a clutch C1, and a brake B1.

  Carrier CA1 is coupled to the crankshaft of engine 10. The pinion gear P1 is disposed between the sun gear S1 and the ring gear R1, and meshes with the sun gear S1 and the ring gear R1, respectively. Pinion gear P1 is supported by carrier CA1 so as to be capable of rotating and revolving.

  The rotational speed of the sun gear S1, the rotational speed of the carrier CA1 (that is, the rotational speed of the engine 10), and the rotational speed of the ring gear R1 are connected in a straight line on the collinear chart as shown in FIGS. If any two rotation speeds are determined, the remaining rotation speed is also determined).

  Ring gear R1 is coupled to carrier CA2 of power distribution device 50 and rotates integrally with carrier CA2.

  The clutch C1 is a hydraulic friction engagement element capable of connecting the sun gear S1 and the carrier CA1. When the clutch C1 is engaged, the sun gear S1 and the carrier CA1 are connected. When the clutch C1 is released, the sun gear S1 and the carrier CA1 are disconnected.

  The brake B1 is a hydraulic friction engagement element that can restrict (lock) the rotation of the sun gear S1. When the brake B1 is engaged, the sun gear S1 is fixed to the gear case (vehicle body), so that the rotation of the sun gear S1 is restricted. When the brake B1 is released, the sun gear S1 is disconnected from the gear case (vehicle body), so that the sun gear S1 is allowed to rotate.

  The speed ratio of the transmission 40 (the ratio between the rotational speed of the carrier CA1 as an input element and the rotational speed of the ring gear R1 as an output element, specifically, the rotational speed of the carrier CA1 / the rotational speed of the ring gear R1) is determined by the clutch C1. And switching according to the combination of engagement and release of the brake B1. When the clutch C1 is engaged and the brake B1 is released, a low gear stage Lo having a gear ratio of 1.0 (directly connected state) is formed. When the clutch C1 is released and the brake B1 is engaged, a high gear stage Hi is formed in which the gear ratio becomes a value smaller than 1.0 (for example, 0.7, so-called overdrive state). Note that when the clutch C1 is engaged and the brake B1 is engaged, the rotation of the sun gear S1 and the carrier CA1 is restricted, so that the rotation of the ring gear R1 is also restricted. In the present embodiment, the case where the transmission 40 switches between two gear stages, the low gear stage Lo and the high gear stage Hi, will be described as an example. However, the transmission apparatus 40 switches between three or more gear stages. It is also possible to change the gear ratio continuously.

  The vehicle 1 </ b> A includes an electric oil pump (hereinafter also referred to as “EOP”) 61, a mechanical oil pump (hereinafter also referred to as “MOP”) 62, and a hydraulic circuit 63 as a configuration for driving the transmission 40.

  The EOP 61 is driven by a motor (hereinafter also referred to as “internal motor”) provided therein, generates hydraulic pressure, and supplies it to the hydraulic circuit 63. The internal motor of EOP 61 is controlled by a control signal from ECU 100. Therefore, the EOP 61 can operate even when the engine 10 is stopped.

  The MOP 62 is driven by the power of the engine 10 to generate hydraulic pressure, and supplies the hydraulic pressure circuit 63 with the hydraulic pressure. Accordingly, when the engine 10 is operated, the MOP 62 is also driven, and when the engine 10 is stopped, the MOP 62 is also stopped.

  The hydraulic circuit 63 includes solenoid valves that respectively adjust the hydraulic pressure supplied to the clutch C1 and the brake B1 of the transmission 40 using the hydraulic pressure supplied from at least one of the EOP 61 and the MOP 62 as a source pressure. The solenoid valves that drive the clutch C1 and the brake B1 in the hydraulic circuit 63 are controlled by control signals PbC and PbB from the ECU 100.

  ECU 300 causes vehicle 1 to travel in “hybrid travel mode (hereinafter referred to as“ HV travel mode ”)” or “motor travel mode (hereinafter referred to as“ EV travel mode ”). The HV travel mode is a control mode in which the vehicle 1 travels with the power of the engine 10 and the second MG 30. The EV travel mode is a control mode in which the engine 10 is stopped and the vehicle 1 is traveled by at least one power of the first MG 20 or the second MG 30 as described above. During the EV travel mode, ECU 300 travels vehicle 1 with the power of the second MG 30 alone and “both motor travel mode” with vehicle 1 traveling with the power of both first MG 20 and second MG 30. Are selectively switched according to a user's required torque or the like.

  FIG. 9 is a diagram showing an operation engagement table of the clutch C1 and the brake B1 of the transmission 40 in each travel mode. In FIG. 9, “C1”, “B1”, “MG1”, and “MG2” indicate the clutch C1, the brake B1, the first MG20, and the second MG30, respectively. The circles (◯) in the C1 and B1 columns indicate “engaged”, the “×” indicates “released”, and the triangle (Δ) indicates either the clutch C1 or the brake B1 during engine braking. Indicates that Further, “G” in the MG1 column and MG2 column indicates that the operation is performed as a generator, and “M” indicates that the operation is performed as a motor.

  In the HV traveling mode, ECU 300 switches the gear ratio of transmission 40 according to the vehicle speed. When the vehicle 1 is moved forward in the medium / low speed range or when the vehicle 1 is moved backward, the ECU 300 forms the low gear stage Lo by engaging the clutch C1 and releasing the brake B1 (see FIG. 10 described later). On the other hand, when the vehicle 1 is advanced in the high speed range, the ECU 300 forms the high gear stage Hi by releasing the clutch C1 and engaging the brake B1 (see FIG. 11 described later). Further, in the HV traveling mode, ECU 300 operates first MG 20 as a generator and operates second MG 30 as a motor.

  In the EV travel mode, the ECU 300 selectively switches between the single motor travel mode and the both motor travel mode as described above. When the vehicle 1 is driven (forward or reverse) in the single motor travel mode, the ECU 300 releases the clutch C1 and releases the brake B1 to place the transmission 40 in a neutral state (a state in which no power is transmitted). When the vehicle 1 is braked in the single motor traveling mode and the engine brake is necessary, the ECU 300 engages one of the clutch C1 and the brake B1. As a result, the rotation of the drive wheel 90 is transmitted to the engine 10, thereby causing a so-called engine brake state in which the engine 10 is rotated. In the single motor traveling mode, ECU 300 operates first MG 20 as a generator and operates second MG 30 as a motor.

  On the other hand, when the vehicle 1 is driven (forward or reverse) in the dual motor travel mode, the ECU 300 engages the clutch C1 and engages the brake B1 to restrict (lock) the rotation of the ring gear R1 of the transmission 40. . Accordingly, the rotation of the carrier CA2 of the power distribution device 50 connected to the ring gear R1 of the transmission 40 is also restricted (locked), so that the carrier CA2 of the power distribution device 50 is maintained in a stopped state. ECU 300 operates first MG 20 and second MG 30 as motors.

  10 and 11 show collinear diagrams in the HV traveling mode (Hi / Lo). 10 and 11, “S1,” “CA1,” and “R1” indicate the sun gear S1, the carrier CA1, and the ring gear R1 of the transmission 40, respectively. “S2,” “CA2,” and “R2” indicate the power distribution devices. 50 sun gear S2, carrier CA2, and ring gear R2 are shown.

  With reference to FIG. 10, the control state when traveling forward at the low gear stage Lo in the HV traveling mode will be described. When the low gear stage Lo is formed, the clutch C1 is engaged and the brake B1 is released. Therefore, the rotation elements S1, CA1, and R1 rotate together. Thereby, the ring gear R1 of the transmission 40 also rotates at the same rotational speed as the carrier CA1, and the rotation of the engine 10 is transmitted from the ring gear R1 to the carrier CA2 of the power distribution device 50 at the same rotational speed. That is, the torque of the engine 10 (hereinafter referred to as “engine torque Te”) input to the carrier CA1 of the transmission 40 is transmitted from the ring gear R1 of the transmission 40 to the carrier CA2 of the power distribution device 50. The torque output from the ring gear R1 (hereinafter referred to as “transmission unit output torque Tr1”) is the same as the engine torque Te (Te = Tr1).

  The rotation of the engine 10 transmitted to the carrier CA2 of the power distribution device 50 is steplessly changed by the rotation speed of the sun gear S2 (rotation speed of the first MG 20) and transmitted to the ring gear R2 of the power distribution device 50. At this time, ECU 300 operates first MG 20 as a generator, and causes torque of first MG 20 (hereinafter referred to as “first MG torque Tm1”) to act in the negative direction. As a result, the first MG torque Tm1 takes charge of the reaction force for transmitting the engine torque Te input to the carrier CA2 to the ring gear R2.

  Engine torque Te transmitted to ring gear R2 (hereinafter referred to as “engine transmission torque Tec”) is transmitted from counter drive gear 51 to counter shaft (output shaft) 70 and acts as a driving force for vehicle 1.

  Further, in the HV traveling mode, ECU 300 operates second MG 30 as a motor. Torque of the second MG 30 (hereinafter referred to as “second MG torque Tm2”) is transmitted from the reduction gear 32 to the counter shaft (output shaft) 70 and acts as a driving force of the vehicle 1. That is, in the HV traveling mode, the vehicle 1 travels using the engine transmission torque Tec and the second MG torque Tm2.

  FIG. 11 illustrates a case where the vehicle is traveling forward at the high gear stage Hi in the HV traveling mode. Since the brake B1 is engaged when the high gear stage Hi is formed, the rotation of the sun gear S1 is restricted. Thus, the rotation of the engine 10 input to the carrier CA1 of the transmission 40 is increased and transmitted from the ring gear R1 of the transmission 40 to the carrier CA2 of the power distribution device 50. Therefore, the transmission output torque Tr1 is smaller than the engine torque Te (Te> Tr1).

  In the hybrid vehicle 1 </ b> A having such a transmission 40, even if the output torque of the engine 10 is the same, the torque transmitted to the carrier CA <b> 2 of the power distribution device 50 varies depending on the gear position of the transmission 40. More specifically, as shown in FIGS. 10 and 11, when the output torque of the engine 10 is the same, the carrier when the high gear stage Hi is selected is greater than the carrier when the low gear stage Lo is selected. The torque transmitted to CA2 increases.

  Therefore, in such a configuration in which the transmission 40 is provided, when the high gear stage Hi is selected, the torque correction amount of the second MG for canceling the torque fluctuation of the engine 10 is greater than that at the low gear stage Lo. growing. Accordingly, it is necessary to increase the torque reduction amount for suppressing the rattling noise.

  Therefore, in the second embodiment, a method is adopted in which control parameters used for torque correction control are stored as different values for the high gear stage Hi and the low gear stage Lo, and the corresponding control parameters are used according to the gear stage.

  FIG. 12 is a flowchart for illustrating torque correction control executed by ECU 300 in the second embodiment. In FIG. 12, steps S125 to S127 are added to the flowchart described in FIG. 7 of the first embodiment, and step S160 is replaced with S160A. In FIG. 12, the description of the same steps as those in FIG. 7 will not be repeated.

  Referring to FIG. 12, when ECU 300 receives an engine stop instruction during load operation of engine 10 (YES in S110) (YES in S120), ECU 300 advances the process to S125 to determine the current speed change device 40. It is determined whether or not the gear position is the high gear stage Hi.

  If the gear position of transmission 40 is high gear stage Hi (YES in S125), the process proceeds to S126, and ECU 300 obtains the control parameter for high gear stage Hi stored in the storage device. The control parameters include, for example, the torque correction amount of the second MG 30 with respect to the engine torque, the torque correction rate for suppressing the rattling noise, the throttle amount of the throttle opening, and the like.

  On the other hand, when the gear position of transmission 40 is low gear stage Lo (NO in S125), the process proceeds to S127, and ECU 300 acquires the control parameter for low gear stage Lo.

  Thereafter, ECU 300 calculates the torque correction amount of second MG 30 using the acquired control parameter (S130), and executes engine stop control (S140).

  Also in the second embodiment, after executing the engine stop control, the actual vehicle behavior and the rattling sound are evaluated (S150), and the learning control of the control parameter is performed based on the evaluation (S160A).

  At this time, as shown in FIG. 13, if the vehicle behavior in one shift stage is known, it is possible to estimate (convert) the vehicle behavior in the other shift stage, and therefore learning control in S160A. In step S150, learning control is also performed based on the evaluation in S150 for the control parameters of the gears that are not currently in use. As a result, the actual behavior can be reflected in the control parameters of the unused gear.

  By performing control according to the above-described processing, even in a hybrid vehicle having a configuration in which a transmission is provided between the engine and the power distribution device, torque fluctuations associated with stopping the engine during load operation, It is possible to improve driving comfort while achieving both the prevention of hitting sound.

  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.

  1, 1A vehicle, 10 engine, 20, 30 motor generator, 21, 31 rotating shaft, 25, 35 inverter, 32 reduction gear, 40 transmission, 50 power distribution device, 51 counter drive gear, 61 EOP, 62 MOP, 63 Hydraulic circuit, 71 counter driven gear, 72 differential drive gear, 80 differential, 81 differential ring gear, 82 drive shaft, 90 drive wheel, 300 ECU, B1 brake, C1 clutch, CA1, CA2 carrier, P1, P2 pinion gear, R1, R2 ring gear, S1, S2 sun gear.

Claims (1)

An internal combustion engine coupled to the drive shaft;
A rotating electrical machine coupled to the drive shaft via a counter gear;
A control device for controlling the rotating electrical machine,
When the internal combustion engine is stopped from a state where the internal combustion engine and the rotary electric machine are driven, the control device is configured to cancel the torque fluctuation of the rotary electric machine accompanying the stop of the internal combustion engine. Configured to correct the output torque,
The control device reduces the correction amount based on the correction amount of the output torque and the output torque of the rotating electric machine before correction,
The control device is a hybrid vehicle in which the reduction amount of the correction amount is set to increase as the correction amount increases.

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