JP6056627B2 - Hybrid vehicle travel control device - Google Patents

Description

  The present invention relates to a drive control apparatus for a hybrid vehicle including an engine and an electric motor as driving power sources for traveling, and more particularly to a technique for protecting a storage battery from overcharging during deceleration traveling.

  A hybrid vehicle is well known that includes an engine and an electric motor that function as a driving force source, and a torque converter with a lock-up clutch provided between the engine and the electric motor and driving wheels. For example, this is a hybrid vehicle described in Patent Document 1. In such a hybrid vehicle, at the time of acceleration traveling, at least one of an engine and an electric motor functioning as a driving force source drives a driving wheel via a torque converter to satisfy a driver's required driving force. In addition, during deceleration travel, the regenerative power obtained by the power generation of the motor while rotating the motor with the drive wheels of the vehicle and decelerating with the regenerative braking torque of the motor by engaging the lock-up clutch of the torque converter. The battery is charged.

JP 2007-178000 A JP 2010-143511 A

  By the way, when the conventional hybrid vehicle decelerates, if the remaining charge of the storage battery reaches near the upper limit value, further charging cannot be performed to prevent overcharging, and regenerative braking by the electric motor is continued. Then, there was a case where the storage battery could not be protected.

  On the other hand, Patent Document 2 discloses a control for releasing the lock-up clutch and stopping regeneration by the electric motor when the remaining charge amount of the storage battery reaches near the upper limit during deceleration traveling.

  However, according to such control, the protection of the storage battery is achieved, but the release of the lock-up clutch and the regeneration stop by the electric motor are performed at the same time. There was a problem that a sense of incongruity occurred and drivability was impaired.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is that the drivability of the vehicle is not so great even when it becomes difficult to charge the storage battery during deceleration traveling of the vehicle. An object of the present invention is to provide a travel control device for a hybrid vehicle that is not damaged.

Between where the gist of the present invention for achieving the above object, (a) and an engine and an electric motor, and the engine separating clutch disposed between the engine and the electric motor, the motor and drive wheels Of a hybrid vehicle comprising: a fluid transmission device with a lock-up clutch provided on a storage battery; a storage battery for transferring power to and from the electric motor; and a transmission provided between the fluid transmission device and the drive wheel . a travel control device, when the protection from overcharge of the battery is requested during deceleration engaged lockup clutch released and the fluid power transmission device; (b) engine separating clutch, If accumulating remaining charge on the battery increases above a first judgment value set in advance, it performs a first protection control for releasing the lock-up clutch, during the execution of the first protection control When the remaining charge of the storage battery increases beyond a preset second determination value, in addition to the first protection control, a second protection control for engaging the engine connecting / disconnecting clutch is executed, When the remaining charge of the storage battery increases beyond the third determination value set larger than the second determination value during the execution of the first protection control and the second protection control, the clutch in the transmission is released. The third protection control is to be executed .

In this way, when the remaining charge of the storage battery increases beyond a preset first determination value, the first protection control for releasing the lockup clutch is executed, and the execution of the first protection control is performed. If the remaining charge of said storage battery increases above a second judgment value set in advance, the second protective control engaging the engine separating clutch in addition to the first protection control is performed during Therefore, the drivability of the vehicle is maintained while protecting the storage battery, and the rotation of the electric motor is suppressed by the rotational resistance of the engine to make it difficult to charge the storage battery, so that the storage battery is protected. Further, when the remaining charge amount of the storage battery increases beyond the third determination value set larger than the second determination value during the execution of the first protection control and the second protection control, By executing the third protection control for releasing the clutch, the rotation of the electric motor is suppressed by disconnecting the driving wheel, making it difficult to charge the storage battery, so that the storage battery is protected.

  Here, preferably, as the remaining charge of the storage battery is smaller, the frequency of executing the first protection control is increased than the second protection control as compared to the case where the remaining amount is larger. In this way, the storage battery can be protected without degrading the drivability by releasing the lockup clutch when the remaining charge of the storage battery is small and there is a lot of room for charging.

It is a figure explaining the schematic structure of the hybrid vehicle to which this invention is applied, and is a figure explaining the principal part of the control system in a vehicle. It is a functional block diagram explaining the principal part of the control function of an electronic controller. Flowchart for explaining control for achieving both vehicle drivability and storage battery protection when the main part of the control operation of the electronic control unit is restricted, that is, when charging of the storage battery is restricted by regenerative electric power from the electric motor when the vehicle is decelerated. It is.

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

  FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and a diagram illustrating a main part of a control system for various controls in the vehicle 10. In FIG. 1, a vehicle 10 is a hybrid vehicle including a power transmission device 12, an engine 14 that functions as a driving force source for traveling, and an electric motor MG. In the transmission case 20 as a non-rotating member, the power transmission device 12 includes an engine connecting / disconnecting clutch K0 (hereinafter referred to as a clutch K0), a torque converter 16 with a lockup clutch L / C, A transmission 18 and the like are provided. The power transmission device 12 is connected to a propeller shaft 26 connected to a transmission output shaft 24 that is an output rotating member of the automatic transmission 18, a differential gear 28 connected to the propeller shaft 26, and the differential gear 28. And a pair of axles 30 and the like. The power transmission device 12 configured in this manner is suitably used for, for example, an FR (front engine / rear drive) type vehicle 10. In the power transmission device 12, the power of the engine 14 (the torque and the force are synonymous unless otherwise distinguished) is the engine connection shaft 32 that connects the crankshaft of the engine 14 and the clutch K0 when the clutch K0 is engaged. Are transmitted to the pair of drive wheels 34 through the clutch K0, the torque converter 16, the automatic transmission 18, the propeller shaft 26, the differential gear 28, the pair of axles 30, and the like in order. The electric motor MG is connected to a power transmission path between the clutch K0 and the torque converter 16 in the transmission case 20, and the power of the electric motor MG is driven through the torque converter 16, the automatic transmission 18 and the like sequentially. 34. Thus, the power transmission device 12 constitutes a power transmission path from the engine 14 to the drive wheels 34.

  The torque converter 16 is a fluid transmission device that outputs the power input to the pump impeller 16a through the fluid to output from the turbine impeller 16b. The pump impeller 16a is connected to the engine connecting shaft 32 via the clutch K0 and directly connected to the electric motor MG. The turbine impeller 16 b is directly connected to a transmission input shaft 36 that is an input rotation member of the automatic transmission 18. An oil pump 22 is connected to the pump impeller 16a. The oil pump 22 is rotationally driven by the engine 14 (and / or the electric motor MG), thereby generating a hydraulic pressure for performing a shift control of the automatic transmission 18 and an engagement release control of the clutch K0. This is an oil pump.

  The automatic transmission 18 constitutes a part of a power transmission path between the engine 14 and the electric motor MG and the drive wheels 34, and the power from the driving power source for travel (the engine 14 and the electric motor MG) is directed to the drive wheels 34. A transmission for transmission. The automatic transmission 18 is a known planet in which a plurality of shift stages (gear stages) having different gear ratios (gear ratios) γ (= transmission input rotation speed Nin / transmission output rotation speed Nout) are selectively established. A gear type multi-stage transmission or a known continuously variable transmission whose gear ratio γ is continuously changed continuously. The automatic transmission 18 includes a plurality of friction engagement devices that selectively establish a plurality of gear stages by controlling, for example, a hydraulic actuator by a hydraulic control circuit 40. By selectively engaging the two, a predetermined gear stage (gear ratio) corresponding to the driver's accelerator operation, vehicle speed V, or the like is established. When the vehicle is operated to the parking position or the neutral position, all the friction engagement devices are released, so that the power transmission path in the automatic transmission 18 is released. In FIG. 1, the plurality of friction engagement devices are representatively shown as the clutch CL.

  The electric motor MG is a so-called motor generator that functions as a prime mover, and has a function as a motor that generates mechanical power from electric energy and a function as a generator that generates electric energy from mechanical energy. This motor MG is composed of a permanent magnet type motor (IPM), for example, a three-phase permanent magnet type synchronous motor (IPM) in which a plurality of magnetic poles are formed in a rotor by magnetization and a stator forms a rotating magnetic field. Has been.

  The electric motor MG is connected to the battery unit 52 via a power supply control unit (PCU) 50. The electric motor MG functions as a driving force source for traveling that generates traveling power together with the engine 14 as an alternative to the engine 14 that is a power source. The electric motor MG generates electric energy by regeneration from the power generated by the engine 14 and the driven force input from the driving wheel 34 side, and stores the electric energy in the battery unit 52 via the power supply control unit 50. And so on. The electric motor MG is operatively connected to the pump impeller 16a, and power is transmitted between the electric motor MG and the pump impeller 16a. Therefore, the electric motor MG is connected to the transmission input shaft 36 of the automatic transmission 18 so as to be able to transmit power without using the clutch K0.

  The starter motor SM has a pinion that meshes with a ring gear provided on the crankshaft 32 of the engine 14 on the output shaft, and rotationally drives the engine 14 when the engine 14 is started. Further, a part of the output torque of the engine 14 is converted into electric energy.

  The clutch K0 is, for example, a wet multi-plate hydraulic friction engagement device in which a plurality of friction plates stacked on each other are pressed by a hydraulic actuator. The hydraulic control circuit 40 uses the hydraulic pressure generated by the oil pump 22 as a source pressure. Is engaged and released. In the engagement release control, the torque capacity of the clutch K0 (hereinafter referred to as K0 torque) is changed by adjusting the pressure of a linear solenoid valve or the like in the hydraulic control circuit 40, for example. In the engaged state of the clutch K0, the pump impeller 16a and the engine 14 are integrally rotated via the engine connecting shaft 32. Therefore, the engine 14 and the electric motor MG are indirectly connected via the clutch K0 without differential relative rotation. On the other hand, in the released state of the clutch K0, power transmission between the engine 14 and the pump impeller 16a is interrupted. That is, the engine 14 and the drive wheel 34 are disconnected by releasing the clutch K0. Since the electric motor MG is connected to the pump impeller 16a, the clutch K0 is provided in a power transmission path between the engine 14 and the electric motor MG, and also functions as a clutch that connects and disconnects the power transmission path.

  The power supply control unit 50 compares the inverter unit 54 that controls transmission and reception of electric power related to the operation of the electric motor MG, the boost converter unit 56 disposed between the battery unit 52 and the inverter unit 54, and the comparison on the battery unit 52 side. DC / DC converter 60 that charges auxiliary battery 58 by stepping down the target high voltage to a low voltage of about 12V to 24V, and relay DR that controls electric motor SM for starting by supplying electric power of auxiliary battery 58 And an input capacitor (or filter capacitor) Ci provided between terminals of the boost converter unit 56 on the battery unit 52 side.

  The inverter unit 54 includes, for example, a known switching element, and in response to a command from an electronic control device 90 (particularly, MG_ECU), which will be described later, to obtain the output torque or regenerative torque required for the electric motor MG. The switching operation of the switching element is controlled. Boost converter unit 56 functions as a reactor L, an upper arm 62 (switching element Q1 and diode D1), a lower arm 64 (switching element Q2 and diode D2), and a power storage member that temporarily stores electric power related to the operation of electric motor MG. A smoothing capacitor Cs and a discharge resistor Rd provided in parallel with the smoothing capacitor Cs are provided. The discharge resistor Rd has a sufficiently large resistance value. For example, when the ignition is off, the charge stored in the smoothing capacitor Cs is slowly discharged.

  The battery unit 52 includes, for example, a storage battery 68 that is a chargeable / dischargeable secondary battery such as a lithium ion assembled battery or a nickel hydride assembled battery, and a power control unit 50 according to a command from an electronic control device 90 (particularly, HV_ECU) described later. System relays SR1 and SR2 that open and close the electrical path between the power supply control unit 50 and the power supply control unit 50.

  The vehicle 10 is provided with an electronic control device 90 including a control device for the vehicle 10 related to control of the entire vehicle, for example. The electronic control unit 90 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 90 performs output control of the engine 14, drive control of the motor MG including regeneration control of the motor MG, shift control of the automatic transmission 18, torque capacity control of the clutch K0, and the like. The computer is divided into a hybrid control computer (HV_ECU), a motor control computer (MG_ECU), a shift control computer (AT_ECU), and the like that control the entire vehicle as necessary. The electronic control unit 90 includes various sensors (for example, an engine rotational speed sensor 70, a turbine rotational speed sensor 72, an output shaft rotational speed sensor 74, an electric motor rotational speed sensor 76, an accelerator opening sensor 78, an acceleration sensor 80, a battery sensor 82, Various signals (for example, the engine rotation speed Ne, which is the rotation speed of the engine 14, the turbine rotation speed Nt, that is, the transmission input shaft 36 of the transmission input shaft 36) based on the detection values by the motor rotation phase sensor 84, the motor drive current sensor 86, the lever position sensor 88, etc. Transmission input rotation speed Nin which is the rotation speed, transmission output rotation speed Nout which is the rotation speed of the transmission output shaft 24 corresponding to the vehicle speed V, motor rotation speed Nmg which is the rotation speed of the electric motor MG, vehicle 10 by the driver The accelerator opening θacc corresponding to the required drive amount with respect to the acceleration acting on the vehicle 10 ( Or deceleration) G, charge state (charge capacity) SOC of the storage battery 68, rotation phase θ of the motor MG, drive currents Iu, Iv, Iw to the motor MG, position Ps of the shift lever 89, etc.) The From the electronic control unit 90, various command signals (for example, an engine control command signal Se, an electric motor) are provided to each device (for example, the engine 14, the inverter unit 54, the hydraulic control circuit 40, the battery unit 52, the relay DR, etc.) provided in the vehicle 10. Control command signal Sm, hydraulic control command signal Sp, power control command signal Sbat, start signal Sss, etc.).

  FIG. 2 shows a main part of the control function by the electronic control unit 90, that is, a key of the control function for protecting the storage battery 68 from overcharge during deceleration traveling of a vehicle in which the accelerator opening θacc is zero and the vehicle speed V is equal to or higher than a predetermined value. It is a functional block diagram explaining a part. The electronic control device 90 or the hybrid control unit 92 included therein also functions as a storage battery protection control device that protects the storage battery 68 from overcharging during deceleration traveling.

  In FIG. 2, the hybrid control means included in the HV_ECU, that is, the hybrid control unit 92 includes a function for controlling the driving of the engine 14 and a function for instructing the operation of the electric motor MG. And control of the entire vehicle 10 including hybrid drive control that travels using the power as a driving force source. For example, the hybrid control unit 92 calculates a required drive torque Touttgt as a drive request amount (that is, a driver request amount) for the vehicle 10 by the driver based on the accelerator opening θacc and the vehicle speed V, and transmission loss, auxiliary load, In consideration of the gear ratio γ of the automatic transmission 18, the charging capacity SOC of the storage battery 68, and the like, the output torque of the driving power source (engine 14 and electric motor MG) for obtaining the required driving torque Touttgt is calculated. The hybrid control unit 92 controls the throttle valve opening, the fuel injection amount (fuel supply amount), the ignition timing, and the like so that the calculated output torque (engine torque) Te of the engine 14 is obtained. Se is output. Further, the hybrid control unit 92 outputs a command signal for controlling the electric motor MG to the electric motor control unit 94 to be described later so that the calculated output torque (MG torque) Tmg of the electric motor MG is obtained. The required drive amount includes, in addition to the required drive torque Touttgt [Nm] in the drive wheel 34, the required drive force [N] in the drive wheel 34, the required drive power [W] in the drive wheel 34, and the request in the transmission output shaft 24. The transmission output torque, the required transmission input torque at the transmission input shaft 36, and the like can also be used. Further, the accelerator opening degree θacc [%], the throttle valve opening degree, the intake air amount, or the like can also be used as the required drive amount.

  When the hybrid controller 92 performs motor traveling (EV traveling) using only the electric motor MG as a driving power source for traveling, the clutch K0 is released and the power transmission path between the engine 14 and the torque converter 16 is released. And the MG torque Tmg necessary for EV traveling is output from the electric motor MG by the electric motor control unit 94 described later. On the other hand, the hybrid control unit 92 engages the clutch K0 and engages the engine 14 and the torque converter 16 when performing engine traveling that travels at least using the engine 14 as a driving force source for traveling, that is, hybrid traveling (EHV traveling). The motor control unit 94 outputs the MG torque Tmg as the assist torque from the electric motor MG as needed while outputting the engine torque Te necessary for EHV traveling to the engine 14. In addition, the hybrid control unit 92 basically stops the operation of the engine 14 while releasing the clutch K0 and engages the lockup clutch L / C while the vehicle is decelerating. Regeneration is performed by the directly connected electric motor MG, and the storage battery 68 is charged using the electric power regenerated by the electric motor MG.

  The electric motor control unit 94 controls the inverter unit 54 and the like based on the command signal from the hybrid control unit 92 (that is, based on communication with the hybrid control unit 92) so as to obtain the necessary MG torque Tmg. The motor control command signal Sm to output is output to control the operation of the motor MG as a driving force source or a generator.

  The shift control unit 96 is based on, for example, a predetermined state (shift diagram, shift map; not shown) based on the vehicle state (for example, the actual vehicle speed V and the requested drive amount calculated by the hybrid control unit 92). Then, it is determined whether or not the shift of the automatic transmission 18 should be executed, and a hydraulic control command signal Sp (for example, a shift command value) for obtaining the determined gear stage (gear ratio) is output to the hydraulic control circuit 40. Thus, the automatic transmission control of the automatic transmission 18 is executed.

  Here, the hybrid control unit 92 performs regeneration of the electric motor MG so that the storage battery 68 is protected while giving priority to drivability, instead of causing the electric motor MG to regenerate the vehicle during deceleration traveling. In order to prioritize the protection of the storage battery 68 as the power increases, a first protection control for releasing the lock-up clutch L / C, a second protection control for engaging the clutch K0, according to the remaining charge SOC of the storage battery 68, and The third protection control for releasing the clutch CL in the automatic transmission 18 is selectively executed. Therefore, the hybrid control unit 92 includes a deceleration traveling determination unit 100, a remaining charge determination unit 102, a first protection control unit 104, a second protection control unit 106, and a third protection control unit 108.

  The deceleration traveling determination unit 100 indicates that the accelerator pedal is not operated based on the accelerator opening θacc being zero, and the vehicle is traveling based on the vehicle speed V being equal to or higher than a predetermined value. Is displayed, it is determined that the vehicle is traveling at a reduced speed.

  In the remaining charge determination unit 102, the remaining charge SOC of the storage battery 68 detected based on the actual terminal voltage of the storage battery 68 from the relationship stored in advance is set to a first determination value A1 and a second determination value that are set in advance. It is determined whether or not it is larger than A2 and the third determination value A3. These first determination value A1, second determination value A2, and third determination value A3 are experimentally determined stepwise in advance to protect the storage battery 68 from overcharge and maintain its durability. Yes, the first determination value A1 is a relatively smaller value than the second determination value A2, and the third determination value A3 is a relatively larger value than the second determination value A2. That is, there is a relationship of A1 <A2 <A3. The remaining charge SOC is an amount indicating the state of charge, that is, the ratio (%) of the actual charge capacity to the full charge capacity (100%). The first determination value A1, the second determination value A2, and the third determination value A3 are sequentially determined near the upper limit value of the operation range set in consideration of the durability of the storage battery 68.

  The first protection control unit 104 releases the lock-up clutch L / C when the remaining charge SOC of the storage battery 68 is determined to have increased beyond the first determination value A1 by the remaining charge determination unit 102. 1 Execute protection control. During deceleration traveling with the clutch K0 disengaged and the lockup clutch L / C engaged, the motor MG was directly connected to the drive wheels 34, but the lockup clutch L / C was released. Since the rotation difference of the torque converter 16 is generated and the regeneration (rotation) of the electric motor MG is alleviated, the storage battery 68 is protected. At the same time, the rotational force of the drive wheels 34 is transmitted to the electric motor MG via the torque converter 16, so that the vehicle continues to decelerate and the drivability is not significantly impaired.

  The second protection control unit 106 releases the lockup clutch L / C when it is determined by the remaining charge determination unit 102 that the remaining charge SOC of the storage battery 68 has increased beyond the second determination value A2. In addition to the first protection control, the second protection control for engaging the clutch K0 is executed. By engaging the clutch K0, the crankshaft 32 of the inactive engine 14 and the electric motor MG are connected and the engine 14 is rotated, so that the rotational resistance of the engine 14 is added to the electric motor MG and the Regeneration (rotation) of electric motor MG is suppressed, and storage battery 68 is protected. In addition, since the rotational resistance of the engine 14 is added and the vehicle continues to decelerate, the drivability is not significantly impaired.

  The third protection control unit 108 releases the lockup clutch L / C when it is determined by the remaining charge determination unit 102 that the remaining charge SOC of the storage battery 68 has increased beyond the third determination value A3. In addition to the first protection control and the second protection control for engaging the clutch K0, the third protection control for releasing the clutch CL in the automatic transmission 18 is executed. Since the power transmission path in the automatic transmission 18 is interrupted by releasing the clutch CL in the automatic transmission 18, the drive wheels 34 are disconnected from the engine 14, the electric motor MG, and the torque converter 16. Thereby, regeneration (rotation) of the electric motor MG is stopped and the storage battery 68 is protected. At the same time, the third protection control unit 108 maintains the same deceleration in order to prevent the vehicle from suddenly coming off from the previous deceleration due to the release of the clutch CL in the automatic transmission 18. Thus, a side brake or a wheel brake (not shown) is operated.

  FIG. 3 shows the main part of the control operation of the hybrid control unit 92 of the electronic control unit 90, that is, the storage battery 68 is protected from overcharge during deceleration traveling of the vehicle in which the accelerator opening θacc is zero and the vehicle speed V is equal to or higher than a predetermined value. 5 is a flowchart for explaining a main part of the control operation, and is repeatedly executed with an extremely short cycle time of, for example, about several milliseconds to several tens of milliseconds.

  In FIG. 3, in S1 corresponding to the deceleration traveling determination unit 100, whether or not the vehicle is decelerating is determined based on whether or not the accelerator opening θacc is zero and the vehicle speed V is equal to or greater than a predetermined value. The If the determination in S1 is negative, the present routine is terminated. If the determination is positive, S2 corresponding to the remaining charge determination unit 102 is executed.

  In S2, it is determined whether or not the remaining charge SOC of the storage battery 68 has increased beyond a preset first determination value A1. If the determination in S2 is negative, this routine is terminated. If the determination is positive, in S3 corresponding to the first protection control unit 104, the clutch K0 is released and the lockup clutch L / C is engaged. During the combined deceleration traveling, the lockup clutch L / C is released.

  Next, in S4 corresponding to the remaining charge determination unit 102, it is determined whether or not the remaining charge SOC of the storage battery 68 has increased beyond a preset second determination value A2. If the determination in S4 is negative, this routine is terminated, and the release of the lockup clutch L / C by the first protection control in S3 is continued. However, if the determination in S4 is affirmative, in S5 corresponding to the second protection control unit 106, in addition to the release of the lockup clutch L / C by the first protection control, the clutch K0 is engaged, The engine 14 in the operating state is rotated.

  Next, in S6 corresponding to the remaining charge determination unit 102, it is determined whether or not the remaining charge SOC of the storage battery 68 has increased beyond a preset third determination value A3. If the determination in S6 is negative, this routine is terminated, and the release of the lockup clutch L / C by the first protection control in S3 and the engagement of the clutch K0 by the second protection control in S5 are continued. Is done. However, if the determination in S6 is affirmative, in S7 corresponding to the third protection control unit 108, the lockup clutch L / C is released by the first protection control and the clutch K0 is engaged by the second protection control. In addition, the clutch CL is disengaged and engaged, the power transmission path in the automatic transmission 18 is interrupted, and the drive wheels 34 are disconnected.

  As described above, according to the hybrid control unit (storage battery protection control device) 92 of the electronic control device 90 of this embodiment, the torque converter (fluid transmission device) 16 is locked up according to the remaining charge SOC of the storage battery 68. Since the first protection control for releasing the clutch L / C and the second protection control for engaging the clutch K0 that connects and disconnects between the engine 14 are selected, the drivability of the vehicle is maintained while protecting the storage battery 68. Is done.

  Further, according to the hybrid control unit (storage battery protection control device) 92 of the electronic control device 90 of the present embodiment, the smaller the remaining charge SOC of the storage battery 68, the more the second protection control than the second protection control. 1 Increase the frequency of executing protection control. For this reason, when the remaining charge SOC of the storage battery 68 is small and there is a lot of room for charging, the storage battery 68 can be protected without degrading the drivability by releasing the lockup clutch L / C.

  Further, according to the hybrid control unit (storage battery protection control device) 92 of the electronic control device 90 of the present embodiment, the remaining charge SOC of the storage battery 68 increases during execution of the first protection control, and the second determination value A2 is obtained. If it exceeds the first protection control, the second protection control is executed in addition to the first protection control. Therefore, the first protection control for releasing the lockup clutch L / C and the second protection control for engaging the clutch K0 that connects / disconnects the engine 14 are both executed, so that the rotation of the electric motor MG is caused by the rotational resistance of the engine 14. This makes it difficult to charge the storage battery 68 and protects the storage battery 68.

  In addition, according to the hybrid control unit (storage battery protection control device) 92 of the electronic control device 90 of the present embodiment, the automatic transmission 18 is provided between the torque converter (fluid transmission device) 16 and the drive wheels 34. If the remaining charge SOC of the storage battery 68 further increases and exceeds the third determination value A3 during the execution of the first protection control and the second protection control, the automatic shift is performed by the clutch CL in the automatic transmission 18. The power transmission path in the machine 18 is released. As a result, the storage battery 68 is protected by inhibiting the rotation of the electric motor MG by separating the drive wheels 34 and making it difficult to charge the storage battery 68.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the lockup clutch L / C is released by the first protection control, the clutch K0 is engaged by the second protection control, and the clutch CL is released by the third protection control. Release or engagement includes not only full release or complete engagement, but also a certain degree of slippage.

  In the above-described embodiment, the torque converter 16 is used as the fluid transmission device. However, other fluid transmission devices such as a fluid coupling (fluid coupling) having no torque amplifying action may be used.

  The engine 14 described above is, for example, a gasoline engine that generates power by burning fuel, but may be a diesel engine or other internal combustion engine.

  In the above-described embodiment, the planetary gear type multi-stage automatic transmission 18 is provided in the vehicle 10, but a continuously variable transmission having a forward / reverse switching mechanism or a parallel-shaft always-mesh transmission. It may be. In short, what is necessary is just to have a function of opening a power transmission path by a built-in clutch.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Vehicle 14: Engine 16: Torque converter (fluid transmission)
18: Automatic transmission (transmission)
34: Drive wheel 68: Storage battery 90: Electronic control device (deceleration running control device)
92: Hybrid control unit 100: Deceleration traveling determination unit 102: Remaining charge determination unit 104: First protection control unit 106: Second protection control unit 108: Third protection control unit MG: Electric motor L / C: Lock-up clutch K0 : Engine connecting / disconnecting clutch CL: Clutch in automatic transmission

Claims (2)

An engine and an electric motor, and the engine separating clutch disposed between the engine and the electric motor, a hydraulic power transmission with a lock-up clutch provided between the electric motor and the drive wheels, between said electric motor A travel control device for a hybrid vehicle comprising a storage battery that transmits and receives electric power, and a transmission that is provided between the fluid transmission device and the drive wheel ,
If the protection from overcharge of the battery during deceleration engaged lockup clutch released and the fluid power transmission device the engine separating clutch is requested,
When the remaining charge of the storage battery increases beyond a preset first determination value, the first protection control for releasing the lock-up clutch is executed,
When the remaining charge of the storage battery increases beyond the preset second determination value during the execution of the first protection control, the engine connecting / disconnecting clutch is engaged in addition to the first protection control. 2 Execute protection control,
When the remaining charge of the storage battery increases beyond the third determination value set larger than the second determination value during the execution of the first protection control and the second protection control, the clutch in the transmission A travel control device for a hybrid vehicle, wherein the third protection control for releasing the vehicle is executed .   2. The hybrid vehicle according to claim 1, wherein the lower the remaining charge of the storage battery, the more frequently the first protection control is executed than the second protection control, as compared to a case where the remaining amount is higher. Travel control device.

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