JP2016094111A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle configured so that torque in the vehicle advancement direction acts on a drive shaft by actuation of an internal combustion engine when the hybrid vehicle travels reversely, and capable of dealing with a driver's driving force request and suppressing the cost increase of an electric motor for driving the vehicle.SOLUTION: When there occurs a locked state where a rotary shaft does not rotate even if maximum torque according to a maximum output line 200 in a normal mode is output during reverse travel, a reverse maximum output extension mode is applied. In the reverse maximum output extension mode, a hybrid vehicle can travel reversely with a driving force obtained by increasing maximum torque in the normal mode in accordance with a maximum output line 210. On the other hand, when the locked state does not occur, the driving force in a range in which torque does not exceed the maximum torque according to the maximum output line 200 is set during reverse travel.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a hybrid vehicle, and more specifically, during reverse travel, the driving force for reverse travel in a hybrid vehicle configured so that the torque in the vehicle forward direction acts on the drive shaft by the operation of the internal combustion engine. (Torque) control.

  As one aspect of the hybrid vehicle, a power train configured such that a torque in the vehicle forward direction acts on the drive shaft when the internal combustion engine is operated is disclosed in Japanese Patent Laid-Open No. 2014-040199 (Patent Document 1) and the like. ing. In Patent Document 1, the engine target rotational speed is set on the basis of the accelerator opening and the motor generator temperature during reverse travel accompanied by the operation of the internal combustion engine for battery charging, thereby responding to the accelerator opening requested by the driver. The control for securing the driving force is described.

JP 2014-041099 A

  In a hybrid vehicle such as Patent Document 1, the torque during forward travel may be ensured by the sum of the outputs of the engine and the motor generator (vehicle drive motor). However, during reverse travel, the torque decreases by the engine operation. To do. Therefore, the maximum torque during reverse travel must be ensured by the output torque of the motor generator.

  For this reason, the specs of the vehicle drive motor are determined by the maximum torque secured during reverse travel. Therefore, if the torque during reverse travel is designed excessively, the cost of the vehicle drive motor will increase. On the other hand, in reverse traveling accompanied by climbing obstacles such as steep climbs and steps, it is required to increase the output torque of the vehicle driving motor in response to the driver's accelerator pedal operation.

  The present invention has been made in order to solve such problems, and an object of the present invention is to cause a torque in the vehicle forward direction to act on the drive shaft by the operation of the internal combustion engine during reverse travel. In the configured hybrid vehicle, the driving force (torque) at the time of reverse travel is controlled so as to satisfy both the response to the driving force request from the driver and the suppression of the cost increase of the vehicle driving motor.

  In one aspect of the present invention, a hybrid vehicle includes an internal combustion engine, a vehicle drive motor, a drive shaft, a power transmission mechanism, and a control device. The vehicle driving motor is configured to output a positive rotational torque or a negative rotational torque. The drive shaft rotates in the positive direction when the vehicle moves forward, and rotates in the negative direction when the vehicle moves backward. The power transmission mechanism is configured to transmit the outputs of the internal combustion engine and the vehicle drive motor to the drive shaft. The control device controls the output torque of the vehicle drive motor during reverse travel in accordance with the accelerator operation by the driver. During reverse travel, the power transmission mechanism applies a positive torque to the drive shaft in accordance with the operation of the internal combustion engine, and also acts as a negative rotation torque from the vehicle driving motor as a negative torque with respect to the drive shaft. Configured to let The control device shifts the reverse travel mode from the first mode when there is a state in which the drive shaft does not rotate even when the vehicle drive motor outputs a preset maximum torque in the negative rotation direction during reverse travel. In addition to changing to the second mode, when the reverse travel mode is the second mode, the output of torque in the negative rotation direction exceeding the maximum torque is allowed.

  According to the hybrid vehicle described above, even if the vehicle driving motor outputs the maximum torque in the first mode for special traveling situations such as reverse traveling over obstacles, steps, etc., and steep backward climbing slopes. When a locked state in which the drive shaft does not rotate occurs, reverse traveling with the maximum torque increased can be achieved by applying the second mode. As a result, the vehicle electric motor is designed according to the maximum torque in the first mode, thereby suppressing an increase in cost, and in a driving situation in which a locked state occurs, the vehicle driving force (torque) for backward driving is generated. Can be secured. As a result, the driving force (torque) during reverse travel can be controlled so as to achieve both the response to the driving force request from the driver and the suppression of the cost increase of the vehicle driving motor.

  Preferably, when the reverse travel mode is the first mode, the control device outputs the maximum torque from the vehicle drive motor during one travel from when the travel system is started to when it is stopped. However, if the state where the drive shaft does not rotate exceeds the predetermined period, the reverse travel mode is changed to the second mode.

  In this way, in a driving situation where the locked state occurs even if the accelerator opening degree is almost fully opened, for example, in reverse traveling over obstacles or steps, etc. Correspondingly, the second mode (enlargement mode) can be applied. Thereby, the driving force (torque) in the reverse direction when the accelerator operation is large in the special traveling situation as described above can be ensured.

  Preferably, when the reverse travel mode is the second mode, the control device outputs the maximum torque from the vehicle drive motor during one travel from when the travel system is started to when it is stopped. However, if the state in which the drive shaft does not rotate does not occur exceeds the predetermined number of times, the reverse travel mode is returned from the second mode to the first mode.

  In this way, the second mode (enlarged mode) can be applied by stratifying special users who encounter a traveling situation in which a locked state occurs during backward traveling at a certain frequency.

  According to the present invention, in a hybrid vehicle configured so that the torque in the vehicle forward direction acts on the drive shaft by the operation of the internal combustion engine during reverse travel, the vehicle responds to the drive force request from the driver, and This is to control the driving force (torque) during reverse running so as to achieve both cost reduction of the driving motor.

1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention. It is a collinear diagram of a hybrid vehicle during reverse travel. It is a conceptual diagram explaining the setting map of the drive torque at the time of reverse drive. It is a flowchart which shows the control process for demonstrating the setting process of the reverse torque in reverse drive. It is a mode transition diagram at the time of reverse travel. It is a flowchart explaining the control processing for canceling | expanding expansion mode.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent part in a figure, and the description is not repeated in principle.

(Overall configuration of hybrid vehicle)
FIG. 1 is a block diagram showing a schematic configuration of a hybrid vehicle according to an embodiment of the present invention.

  Referring to FIG. 1, hybrid vehicle 100 includes an engine 10, a first MG (Motor Generator) 20, a second MG 30, a power split device 40, a speed reducer 50, drive wheels 80, and a drive shaft 85. Prepare. Hybrid vehicle 100 further includes an inverter 60, a battery 70, a smoothing capacitor C 1, a converter 90, and an electronic control unit (hereinafter referred to as “ECU”) 150.

  The engine 10 is an internal combustion engine that generates a driving force for rotating a crankshaft by combustion energy generated when an air-fuel mixture sucked into a combustion chamber is combusted. The engine 10 is controlled based on a control signal S4 from the ECU 150.

  First MG 20 and second MG 30 are AC motors, for example, three-phase AC synchronous motors.

  Hybrid vehicle 100 travels by driving force output from at least one of engine 10 and second MG 30. The driving force generated by the engine 10 is divided into two paths by the power split device 40. That is, one is a path transmitted to the drive shaft 85 and the drive wheels 80 via the speed reducer 50, and the other is a path transmitted to the first MG 20. The power split device 40 corresponds to an example of a “power transmission mechanism”.

  Power split device 40 includes a planetary gear including a sun gear SG, a pinion gear PG, a carrier CA, and a ring gear RG. Pinion gear PG engages with sun gear SG and ring gear RG. The carrier CA supports the pinion gear PG so as to be able to rotate, and is connected to the crankshaft of the engine 10. Sun gear SG is coupled to the rotation shaft of first MG 20. Ring gear RG is connected to the rotation shaft of second MG 30 and reduction gear 50.

  First MG 20 operates as a generator using the power of engine 10 transmitted via power split device 40. The electric power generated by the first MG 20 is supplied to the second MG 30 via the inverter 60 and is used as electric power for driving the second MG 30. Further, surplus power that is not used as power for driving the second MG 30 among power generated by the first MG 20 is supplied to the battery 70 via the converter 90 and used as power for charging the battery 70. The power generation amount of first MG 20 is controlled according to the SOC (State of Charge) of battery 70.

  Second MG 30 generates a driving force using at least one of the electric power stored in battery 70 and the electric power generated by first MG 20. Then, the driving force of the second MG 30 is transmitted to the drive shaft 85 and the drive wheels 80 via the speed reducer 50. In FIG. 1, the driving wheel 80 is shown as a front wheel, but the rear wheel may be driven by the second MG 30 instead of or together with the front wheel.

  When the hybrid vehicle 100 is braked, the second MG 30 is driven by the drive wheels 80 via the speed reducer 50 and the drive shaft 85, and the second MG 30 operates as a generator. Thereby, 2nd MG30 functions also as a regenerative brake which converts kinetic energy of vehicles into electric power. The electric power generated by the second MG 30 is stored in the battery 70.

  Inverter 60 includes a first inverter 60-1 and a second inverter 60-2. First inverter 60-1 and second inverter 60-2 are connected to converter 90 in parallel with each other.

  First inverter 60-1 is provided between converter 90 and first MG 20. First inverter 60-1 controls the output of first MG 20 based on control signal S1 from ECU 150. Second inverter 60-2 is provided between converter 90 and second MG 30. Second inverter 60-2 controls the output of second MG 30 based on control signal S2 from ECU 150.

  The battery 70 is typically constituted by a DC secondary battery such as nickel metal hydride or lithium ion. Converter 90 performs voltage conversion between battery 70 and inverter 60. Converter 90 boosts voltage Vb of battery 70 (more precisely, DC voltage VL between positive line PL0 and negative line GL0 for transferring power between converter 90 and battery 70) to increase inverter 60. Output to.

  Smoothing capacitor C1 is connected between positive electrode line PL1 and negative electrode line GL1. The smoothing capacitor C1 smoothes the voltage VH by storing electric charge according to the voltage VH.

  The hybrid vehicle 100 further includes a brake pedal sensor 125, an accelerator pedal sensor 126, a shift position sensor 127, a vehicle speed sensor 129, and rotation angle sensors 131 and 132. Each of these sensors transmits a detection result to ECU 150.

  The brake pedal sensor 125 detects a stroke amount BRK of a brake pedal (not shown) by the driver. The accelerator pedal sensor 126 detects an accelerator opening degree ACC indicating an operation amount of an accelerator pedal (not shown) by the driver. The vehicle speed sensor 129 detects the vehicle speed V of the hybrid vehicle 100 based on the rotational speed of the drive wheels 80 or the drive shaft 85.

  The rotation angle sensor 131 detects the rotor rotation angle θ1 of the first MG 20. The rotation angle sensor 132 detects the rotor rotation angle θ2 of the second MG 30. The rotation angle sensors 131 and 132 are typically constituted by resolvers.

  The shift position sensor 127 detects the shift position SP selected by operating a shift lever (not shown) by the driver. Shift positions selectable by the driver are a neutral position (N position), a parking position (P position) selected during parking, a drive position (D position) selected during forward travel, and an R selected during reverse travel. Includes position. When the R position is selected, the shift range becomes the R range. When the R range is selected, hybrid vehicle 100 is controlled to generate a vehicle driving force (torque) for reverse travel.

  ECU 150 is configured to include a CPU (Central Processing Unit) and a memory (not shown), and is configured to execute arithmetic processing based on detection values by each sensor by software processing according to a map and a program stored in the memory. The Alternatively, at least a part of the ECU may be configured to execute predetermined numerical operation processing and / or logical operation processing by hardware processing using a dedicated electronic circuit or the like. The ECU 150 generates the control signals S1 to S4 described above based on information such as each sensor, and outputs the generated control signals S1 to S4 to each device.

  In hybrid vehicle 100, the ECU 150 executes travel control for performing travel suitable for the vehicle state. For example, when starting the vehicle and traveling at a low speed, the hybrid vehicle 100 travels by the output of the second MG 30 with the engine 10 stopped. During steady running, the engine 10 is started, and the hybrid vehicle 100 runs by the output of the engine 10 and the second MG 30. In particular, the fuel efficiency of the hybrid vehicle 100 is improved by operating the engine 10 at a highly efficient operating point.

(Control of reverse travel)
In hybrid vehicle 100 according to the present embodiment, reverse drive torque (hereinafter also referred to as “reverse torque”) is output as second MG 30 rotates in the negative direction.

  As sun gear SG, carrier CA, and ring gear RG rotate relatively, power split device 40 functions as a differential device. Therefore, the rotational speeds of sun gear SG, carrier CA, and ring gear RG, that is, the rotational speeds of first MG 20, engine 10 and second MG 30, are in a relationship connected by straight lines in the collinear chart as shown in FIG.

  A vertical line Y1 in FIG. 2 indicates the rotational speed of the sun gear SG of the power split device 40, that is, the rotational speed of the first MG 20 (MG1). A vertical line Y2 indicates the rotational speed of the carrier CA of the power split device 40, that is, the rotational speed of the engine 10. Vertical line Y3 indicates the rotation speed of ring gear RG of power split device 40, that is, the rotation speed of second MG 30 (MG2). The intervals between the vertical lines Y1 to Y3 are determined according to the gear ratio of the power split device 40.

  Referring to FIG. 2, in reverse travel with the engine stopped, reverse travel is performed when second MG 30 outputs a negative torque acting in the reverse rotation direction of drive shaft 85 as shown in collinear diagram 195 (dotted line). To do. That is, the second MG 30 corresponds to an example of “a motor for driving a vehicle”.

  The reverse torque Trv of the hybrid vehicle 100 in reverse travel is proportional to the torque Tmg2 (Tmg2 <0) of the second MG 30. Below, reverse torque Trv shall show the torque of a reverse drive direction as a positive value.

  On the other hand, the stop and operation of the engine 10 are also controlled during reverse travel. Even during reverse travel, when the SOC of the battery 70 decreases, reverse travel in which the engine 10 is operated is applied in order to recover the SOC by power generation caused by the operation of the engine 10. Reverse travel with engine operation follows a nomograph 190 indicated by a solid line.

  In reverse travel with engine operation, the engine 10 is controlled to output power for generating the charging power of the battery 70. In general, when the engine for power generation is operated, an operating point (torque × rotational speed) that increases the efficiency of the engine 10 is selected. The first MG 20 outputs negative torque (Tmg1 <0) with respect to the output from the engine 10 to generate power. The generated power is converted into charging power for the battery 70 by the first inverter 60-1. Thus, the battery 70 can be charged by the output of the engine 10 during reverse travel.

  In reverse travel with engine operation, engine direct torque Tep (Tep = −Tmg1 / ρ) according to output torque Tmg1 of first MG 20 is transmitted to ring gear RG (ρ: gear ratio). The engine direct torque Tep corresponds to the torque output to the ring gear RG when the engine 10 is operated at the target rotational speed and the target torque while receiving the reaction force from the engine 10 in the first MG 20.

  As a result, since Tmg1 <0 during reverse travel, the engine direct torque Tep acts on the ring gear RG and the drive shaft 85 as the torque in the forward rotation direction, that is, the vehicle forward direction. For this reason, the reverse torque Trv decreases by | Tep | rather than | Tmg2 |, so that the reverse torque decreases compared to when the engine 10 is stopped.

  Therefore, in the hybrid vehicle 100 shown in FIG. 1, the driving torque cannot be increased by the operation of the engine 10 during reverse travel. For this reason, the maximum torque during reverse travel is ensured by the output of the second MG 30. On the other hand, the driving torque during forward traveling can be ensured by the sum of the engine direct torque Tep accompanying the operation of the engine 10 and the output torque (Tmg2> 0) of the second MG 30.

  Therefore, the specifications of the second MG 30 are determined according to the maximum torque during reverse travel. For this reason, if the maximum torque is excessively designed, the cost of the second MG 30 is increased.

FIG. 3 is a conceptual diagram illustrating a drive torque setting map during reverse travel.
Referring to FIG. 3, the drive torque during reverse travel (hereinafter also referred to as reverse torque Trv) is set according to accelerator opening AC and vehicle speed (reverse travel). The accelerator opening degree AC is shown as a percentage based on a signal from the accelerator pedal sensor 126 with the fully opened state being 100%. As for the reverse torque Trv, the reverse torque is indicated as a positive value. The vehicle speed is detected by a signal from the vehicle speed sensor 129.

  The maximum output line 200 during reverse travel is determined corresponding to the maximum output line of the second MG 30. That is, the maximum torque on the maximum output line 200 corresponds to the torque value when the second MG 30 outputs the maximum torque (negative direction). When accelerator opening degree AC = 100%, reverse torque Trv is set according to maximum output line 200.

  A map for setting the reverse driving force (torque) with respect to the vehicle speed for each accelerator opening AC is determined in advance according to a maximum output line 200 (AC = 100%) and characteristic lines 201-204. Thus, the map of output torque at each accelerator opening is set so that a large driving torque can be obtained at low speeds including when the vehicle starts. When the accelerator opening is maximum, a map is set along the maximum output line 200. At the accelerator opening intermediate between the maximum output line 200 (AC = 100%) and the characteristic lines 201-204 (AC = 80%, 40%, 20%, 0%), the reverse torque Trv is set by linear interpolation of the map value. can do. Further, the output torque Tmg2 of the second MG 30 is set in proportion to the reverse torque Trv thus set.

  Second MG 30 is designed with specifications according to maximum output line 200. Therefore, even if the second MG 30 operates so as to output the torque on the maximum output line 200 continuously for a certain period of time determined by the standard, the physique dimensions and the durability of the parts are prevented so that failure and deterioration of durability do not occur. The sex is designed.

  In the hybrid vehicle according to the present embodiment, the reverse travel mode allows the normal mode in which reverse torque is set according to the normal maximum output line 200 and the torque output exceeding the maximum output line 200 when a predetermined condition is satisfied. , Switched between enlargement mode. That is, the normal mode corresponds to the “first mode”, and the enlargement mode corresponds to the “second mode”.

  In the enlargement mode, reverse torque Trv when accelerator opening degree AC = 100% is set according to maximum output line 210 indicated by a dotted line in FIG. The maximum output line 210 is set in advance so as to output a reverse torque larger than the maximum output line 200 during reverse low-speed traveling with V <Vx as compared with the maximum output line 200. Vx is determined so that a large torque can be secured in response to the start of reverse travel. That is, in the range of V ≧ Vx, the maximum outputs 200 and 210 are the same, and the increase in the maximum torque is suppressed to the minimum.

  FIG. 4 is a flowchart showing a control process for explaining the reverse torque setting process in the reverse travel, and FIG. 5 is a mode transition diagram in the reverse travel. The flowchart shown in FIG. 4 is repeatedly executed by the ECU 150.

  Referring to FIG. 4, ECU 150 clears count value CNT to zero in accordance with the start of the traveling system (so-called Ready ON) in step S100. In the following, it is assumed that one travel (one trip) of the hybrid vehicle 100 is started in response to the start of the travel system and is ended in response to the stop of the travel system (so-called Ready OFF). That is, step S100 is executed in one shot at the start of traveling.

  The driving system is started and stopped by a button and / or pedal operation by the driver. For example, according to the start and stop of the traveling system, power is supplied from the battery 70 by turning on and off a relay (not shown) inserted and connected to the positive line PL1 and / or the negative line GL1 (FIG. 1). Started or ended.

  In step S110, ECU 150 determines whether or not the R range for reverse travel is selected. When the R range is not selected (NO at S110), the reverse torque setting process after step S120 is not executed.

  When the R range is selected (YES in S110), ECU 150 determines whether a locked state is detected in step S120. The locked state is detected when the accelerator opening degree AC is almost fully open (AC = 100%) and the vehicle speed = 0, that is, when the drive wheels 80 (drive shaft 85) are not rotated. For example, when accelerator opening degree AC> Ath and vehicle speed V <ε, step S120 is determined as YES. The predetermined value Ath compared with the accelerator opening degree AC is a predetermined threshold value for detecting that the accelerator opening degree is close to full open. Similarly, the predetermined value ε compared with the vehicle speed V is a predetermined threshold value for detecting that the wheel is stopped.

  ECU 150 counts up count value CNT when a locked state is detected (YES in S120). On the other hand, when the locked state is not detected (NO determination in S120), ECU 150 skips the process of step S130. As a result, the count value CNT increases every time a locked state is detected.

  In step S140, ECU 150 compares count value CNT with determination value Ct. When count value CNT exceeds determination value Ct (when YES is determined in S110), ECU 150 proceeds to step S150 and sets mode flag FLG = 1.

  In step S170, ECU 150 determines whether or not mode flag FLG = 1. When FLG = 1 (when YES is determined in S170), ECU 150 proceeds to step S180 and uses reverse power map 210 at AC = 100% using maximum output line 210 indicated by a dotted line in FIG. Set.

  On the other hand, when FLG = 0 (NO in S170), the process proceeds to step S180, and the reverse torque map at AC = 100% using the maximum output line 200 shown in FIG. Set. That is, the reverse travel in the hybrid vehicle 100 is in a state where the expansion mode is applied when FLG = 1, and is in a state where the normal mode is applied when FLG = 0.

  When count value CNT has not reached determination value Ct (NO determination in S140), ECU 150 advances the process to step S160 to maintain the current value of mode flag FLG. Thereby, the current mode (normal mode or enlargement mode) is maintained. Note that the default value of the mode flag FLG is 0 in order to apply the normal mode.

  Referring to FIG. 5, the reverse travel mode changes from the default normal mode to the expansion mode when a predetermined condition CND1 is satisfied. The condition CND1 is satisfied when step S140 in FIG. 4 is determined as YES. Therefore, when the locked state occurs during a trip exceeding a certain period (the product of the execution cycle of the flowchart in FIG. 4 and the determination value Ct), the expansion mode is applied.

  Note that the processing in steps S120 to S140 determines whether or not the change from the normal mode to the enlargement mode is necessary, and is therefore not executed when the enlargement mode is applied (when FLG = 1 already). Also good. That is, according to the condition CND1 (S120 to S140), when the second MG 30 outputs the maximum torque according to the maximum output line 200 of FIG. 3, the drive wheel 80 (drive shaft 85) does not rotate. In the meantime, the lock state is detected.

  When the enlargement mode is applied, if the predetermined condition CND2 is satisfied, the enlargement mode is canceled and the reverse travel mode returns to the normal mode. On the other hand, the enlargement mode is maintained until a predetermined condition CND2 is satisfied.

  FIG. 6 shows a flowchart for explaining a control process for canceling the enlargement mode.

  Referring to FIG. 6, ECU 150 executes the processing after step S210 in response to the stop (Ready OFF) of the traveling system (when YES is determined in S200). That is, at the end of traveling of hybrid vehicle 100, the processing after step S210 is executed in one shot.

  In step S210, ECU 150 determines whether or not count value CNT that is incremented every time a lock state is detected during the current trip is zero. When the count value CNT is 0, that is, when the locked state is not detected during the trip (YES in S210), the ECU 150 proceeds to step S220 to count up the release count value RCNT. .

  On the other hand, when a locked state is detected during the current trip (NO in S210), ECU 150 proceeds to step S230 and clears release count value RCNT to zero.

  Furthermore, ECU 150 determines in step S240 whether or not release count value RCNT after the end of the current trip exceeds determination value Rt. If the cancellation count value RCNT exceeds the determination value Rt (when YES is determined in S240), the ECU 150 proceeds to step S250 and sets the mode flag FLG to 0. The determination value Rt is set in advance to a predetermined value of 2 or more.

  As a result, when the enlargement mode is applied (FLG = 1), the reverse travel returns to the normal mode again. That is, the condition CND2 in FIG. 5 is satisfied. Note that the normal mode is maintained when the normal mode is applied (FLG = 0).

  If release count value RCNT does not exceed determination value Rt (NO determination in S240), ECU 150 proceeds to step S260 to maintain the current value of mode flag FLG. Thereby, the current mode (normal mode or enlargement mode) is maintained.

  As described above, according to the processing examples in FIGS. 4 and 6, when the locked state in the reverse travel is detected during one trip, the reverse mode is set by applying the expansion mode. On the other hand, once the enlargement mode is applied, the return to the normal mode is not permitted unless the lock state is not detected through a plurality of trips.

  For this reason, a certain frequency is applied to a driving situation in which a locked state is generated even if an operation is performed in which the accelerator opening is almost fully opened, for example, backward traveling over an obstacle or a step, or a steep backward climbing slope. You can stratify the special users you encounter in and apply the magnification mode. Thereby, in the above driving conditions, the reverse driving force (torque) can be appropriately ensured according to the maximum output line 210 (FIG. 3) in which the maximum torque is expanded in response to the accelerator operation by the driver. .

  On the other hand, the reverse torque of the hybrid vehicle 100 is set within a range that does not exceed the maximum output line 200 (FIG. 3) for a user who does not encounter the special driving situation in the reverse traveling as described above. The For this reason, even if it runs using 2nd MG30 designed according to maximum output line 200, failure of 2nd MG30 and a fall of durability do not occur fundamentally.

  As a result, in the hybrid vehicle according to the present embodiment, it is possible to reduce the cost of second MG 30 as compared to the case where second MG 30 is designed according to maximum output line 210 in order to completely cope with a special user. Furthermore, for a special user, it is possible to meet the demand for securing the driving force in the reverse direction by applying a mode for increasing the reverse torque when the accelerator operation is large. Thereby, the driving force (torque) at the time of reverse travel can be controlled so as to achieve both the response to the driving force request from the user and the cost increase suppression of the vehicle driving electric motor (second MG 30).

  It should be noted that the configuration of the power train of the hybrid vehicle is not limited to the illustration in the present embodiment, and will be described in a confirming manner. That is, the reverse torque setting according to the present invention can be commonly applied to a hybrid vehicle having a power train configuration in which the torque in the vehicle forward direction acts on the drive shaft when the internal combustion engine is operated even during reverse travel. It is.

  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.

  10 Engine, 20 1st MG, 30 2nd MG, 40 Power split device, 50 Reducer, 60 Inverter, 60-1 1st inverter, 60-2 2nd inverter, 70 Battery, 80 Drive wheel, 85 Drive shaft, 90 Converter , 100 hybrid vehicle, 125 brake pedal sensor, 126 accelerator pedal sensor, 127 shift position sensor, 129 vehicle speed sensor, 131, 132 rotation angle sensor, 190 nomograph (engine operation), 195 nomograph (engine stop), 200 Maximum output line (normal mode), 210 Maximum output line (enlarged mode), 201-204 characteristic line, AC accelerator opening, C1 smoothing capacitor, CA carrier, CND1, CND2 condition, CNT count value, Ct, Rt judgment value, FLG mode flag, GL , GL1 negative line, PG pinion gear, PL0, PL1 positive line, RCNT release count value, RG ring gear, S1-S4 control signal, SG sun gear, SP shift position, Tep engine direct torque, Tmg1 torque (first MG), Tmg2 torque ( 2nd MG), Trv reverse torque, VL, VH DC voltage.

Claims (3)

An internal combustion engine;
A vehicle driving motor that outputs a positive rotational torque or a negative rotational torque;
A drive shaft that rotates in the positive direction when the vehicle moves forward while rotating in the negative direction when the vehicle moves backward;
A power transmission mechanism for transmitting the output of the internal combustion engine and the vehicle drive motor to the drive shaft;
A control device for controlling the output torque of the motor for driving the vehicle in reverse traveling according to the accelerator operation by the driver,
The power transmission mechanism applies a positive torque to the drive shaft according to the operation of the internal combustion engine during the reverse travel, and applies a negative rotational torque from the vehicle drive motor to the drive shaft. Configured to act as a negative torque,
The controller is
During reverse travel, when the vehicle driving motor outputs a preset maximum torque in the negative rotation direction and the drive shaft does not rotate, the reverse travel mode is changed from the first mode to the first mode. And a hybrid vehicle configured to allow output of torque in the negative rotation direction exceeding the maximum torque when the reverse travel mode is the second mode.   When the reverse drive mode is the first mode, the control device causes the motor for driving the vehicle to output the maximum torque during a single run from when the drive system is started to when it is stopped. 2. The hybrid vehicle according to claim 1, wherein the reverse travel mode is changed to the second mode when a state in which the drive shaft does not rotate even when output is generated exceeds a predetermined period.   When the reverse travel mode is the second mode, the control device outputs the maximum torque from the vehicle drive motor during one travel from when the travel system is started to when it is stopped. 2. The hybrid according to claim 1, wherein if the state where the drive shaft does not rotate does not occur continues for more than a predetermined number of times, the reverse travel mode is returned from the second mode to the first mode. car.

Images