JP2011189800A - Hybrid drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower fuel cost by further improving energy efficiency, in a hybrid drive device having an internal combustion engine and a motor generator. <P>SOLUTION: A continuously variable transmission 35 is provided between the engine 20 and the motor generator 36, a first clutch 34 is provided between the engine 20 and the continuously variable transmission 35, and a second clutch 37 is provided between the motor generator 36 and a drive wheel. Based on vehicle speed, each control unit 51-55 cooperatively blocks the first clutch 34 and the second clutch 37, blocks the second clutch 37 while releasing a normal traveling mode at which a vehicle travels by at least the rotational drive of the engine 20, and releasing the first clutch 34, and switches a motor traveling mode at which the vehicle travels by the rotational force of the motor generator 36, and a first inertial traveling mode at which the hybrid vehicle travels by an inertia force by releasing the secure clutch 37. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hybrid drive device having an internal combustion engine and a motor generator.

  Conventionally, low fuel consumption vehicles have been developed by suppressing environmental deterioration such as global warming and energy saving measures. For example, the technique described in Patent Document 1 includes an engine (internal combustion engine) as a drive source, and stops fuel supply to the engine when a constant speed traveling condition is satisfied such that the vehicle travels at a substantially constant speed. As a result, low fuel consumption is achieved. The technique described in Patent Document 1 performs control to switch between normal travel (engine drive) and inertial travel (engine stop) using a preset vehicle speed reference value, thereby ensuring engine stop time. ing.

  In addition, development of hybrid vehicles equipped with an engine and a motor generator as drive sources and capable of realizing lower fuel consumption is in progress. The hybrid vehicle assists the propulsion force of the vehicle by the engine with a motor generator, or at the time of deceleration, drives the motor generator as a generator to collect kinetic energy as electric energy to charge an on-vehicle storage battery (high voltage battery). Control.

  As a hybrid vehicle, for example, a technique described in Patent Document 2 is known. The technique described in Patent Document 2 includes two clutches, and an engine, a first clutch, a motor generator, an automatic transmission having a second clutch, and drive wheels are connected in this order to constitute a hybrid drive system. Then, the driving mode is switched to “engine driving mode”, “motor driving mode”, “motor assist driving mode”, and “traveling power generation mode” by engaging or releasing the first clutch. The second clutch is slip-engaged at the time of switching each travel mode, thereby preventing the engine start shock and the like from being transmitted to the drive wheels.

Japanese Examined Patent Publication No. 62-057530 JP 2007-015679 A

  The technologies described in Patent Document 1 and Patent Document 2 described above are technologies that improve energy efficiency and achieve low fuel consumption. However, in order to improve energy efficiency, the following improvements are described. There is room for. That is, in the technique described in Patent Document 1, the engine is started when the vehicle speed decreases from inertial running, and the decrease in the vehicle speed is compensated by the driving force of the engine. / Stop is repeated. Therefore, since the engine start that requires a lot of fuel is repeated, it becomes possible to realize a lower fuel consumption by improving this point. Further, since the technique described in Patent Document 1 has many opportunities to start the engine, it is not preferable because the engine start sound frequently leaks into the passenger compartment.

  On the other hand, the technique described in Patent Document 2 employs a configuration in which driving wheels are driven via an automatic transmission even in the “motor running mode”. For this reason, even when there is no need for shifting with a motor generator having a wide driving range, it is necessary to supply shifting hydraulic pressure to the automatic transmission. Therefore, by improving this point, it becomes possible to realize lower fuel consumption. In addition, when the shift hydraulic pressure is obtained with the driving force of the engine, the engine cannot be stopped even when the driving force of the engine is not involved in the running of the vehicle. Can be realized.

  An object of the present invention is to provide a hybrid drive apparatus having an internal combustion engine and a motor generator, which can improve energy efficiency and realize low fuel consumption.

  The hybrid drive device of the present invention is a hybrid drive device having an internal combustion engine and a motor generator, the vehicle speed detecting means for detecting the vehicle speed of the vehicle, the control unit to which the vehicle speed signal from the vehicle speed detecting means is input, A transmission provided between the internal combustion engine and the motor generator and configured to change the rotational speed of the internal combustion engine, and provided between the internal combustion engine and the transmission, between the internal combustion engine and the transmission. A first clutch that fastens or releases the power transmission path of the motor, and a second clutch that is provided between the motor generator and the drive wheel, and that fastens or releases the power transmission path between the motor generator and the drive wheel. And the control unit engages both the first clutch and the second clutch based on the vehicle speed. At least a normal travel mode in which the internal combustion engine is driven to rotate, a motor travel mode in which the second clutch is engaged while the first clutch is released and the motor generator is driven to rotate, and the second clutch is operated. The first inertia traveling mode in which the vehicle is opened and travels by inertia force is switched.

  In the hybrid drive device of the present invention, the control unit engages the first clutch with the second clutch released while the first inertia traveling mode is being executed, and drives the internal combustion engine. A second inertia traveling mode in which the on-vehicle power storage unit is charged by the motor generator is executed.

  In the hybrid drive device of the present invention, the control unit alternately executes the second inertia traveling mode and the motor traveling mode when the remaining energy amount of the in-vehicle power storage unit becomes a predetermined value or less. Features.

  In the hybrid drive device of the present invention, the internal combustion engine is started by a starter motor, and the control unit controls a rotation speed of the motor generator and a transmission gear ratio when the first clutch is engaged. The rotational speeds of the input side and output side of the first clutch are synchronized.

  In the hybrid drive device of the present invention, the internal combustion engine is started by the motor generator, and the control unit opens the second clutch when starting the internal combustion engine in the normal traveling mode or the second inertial traveling mode. Then, after the rotational speed of the motor generator is set to substantially zero, the first clutch is engaged to rotationally drive the motor generator.

  According to the hybrid drive device of the present invention, a transmission that changes the rotational speed of the internal combustion engine is provided between the internal combustion engine and the motor generator, and the internal combustion engine and the transmission are between the internal combustion engine and the transmission. A first clutch for fastening or releasing the power transmission path is provided, and a second clutch for fastening or releasing the power transmission path between the motor generator and the drive wheels is provided between the motor generator and the drive wheels. Based on the vehicle speed, both the first clutch and the second clutch are engaged, and at least the normal travel mode in which the vehicle is driven by the rotational drive of the internal combustion engine, the second clutch is engaged while the first clutch is released, and the motor generator rotates. The motor travel mode for traveling by driving and the first inertia travel mode for disengaging the second clutch and causing the vehicle to travel by the inertial force are switched. Obtain. Thereby, the driving force required for traveling of the vehicle can be obtained from the inertial force of the vehicle, the driving force of the motor generator, and the driving force of the internal combustion engine in accordance with the vehicle speed of the vehicle. Since the second clutch is provided closer to the driving wheel (downstream side) than the internal combustion engine, the first clutch, the transmission, and the motor generator, the friction (friction resistance) of the transmission, etc. located upstream from the second clutch. The driving wheel can be smoothly rotated without being affected by the above. Further, it is not necessary to supply the transmission hydraulic pressure to the transmission as before. Therefore, energy efficiency can be further improved and low fuel consumption can be realized.

  According to the hybrid drive device of the present invention, the control unit engages the first clutch with the second clutch released while the first inertia traveling mode is being executed, and drives the internal combustion engine to operate the motor generator. Since the second inertial running mode for charging the in-vehicle power storage unit is executed, the driving force of the internal combustion engine is not transmitted to the driving wheels, and only the motor generator can be efficiently driven as a generator. Further, since the driving force of the internal combustion engine is not transmitted to the drive wheels, the vehicle speed is not decelerated or accelerated, and the vehicle can continue to travel inertia smoothly.

  According to the hybrid drive device of the present invention, the control unit can alternately execute the second inertia traveling mode and the motor traveling mode when the remaining energy amount of the in-vehicle power storage unit becomes a predetermined value or less.

  According to the hybrid drive device of the present invention, the internal combustion engine is started by the starter motor, and the control unit controls the rotational speed of the motor generator and the transmission gear ratio when the first clutch is engaged, Since the rotation speeds of the input side and the output side are synchronized, it is possible to prevent vibrations and the like from occurring when the first clutch is engaged.

  According to the hybrid drive device of the present invention, when the internal combustion engine is started by the motor generator and the control unit starts the internal combustion engine in the normal traveling mode or the second inertia traveling mode, the second clutch is released to open the motor generator. After setting the rotational speed to substantially zero, the first generator can be engaged to rotate the motor generator.

It is a skeleton figure which shows the outline of the hybrid drive device in this invention. It is a circuit diagram which shows the electrical system of the hybrid drive device of FIG. It is a main flowchart figure which shows the operation | movement content of the hybrid drive device of FIG. FIG. 4 is a sub-flowchart diagram illustrating operation details of acceleration control in the main flowchart of FIG. 3. It is a sub flowchart figure which shows the operation | movement content of the deceleration control in the main flowchart of FIG. FIG. 2 is a timing chart showing a specific operation of the hybrid drive device of FIG. 1. FIG. 2 is a timing chart showing the specific operation of the hybrid drive device of FIG. 1 (with air conditioner SW and SOC displayed).

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

  FIG. 1 is a skeleton diagram showing an outline of a hybrid drive apparatus according to the present invention, and FIG. 2 is a circuit diagram showing an electrical system of the hybrid drive apparatus shown in FIG.

  As shown in FIG. 1, the hybrid drive device 10 includes an engine (internal combustion engine) 20 and a drive mechanism 30 and is mounted on the front side of a hybrid vehicle (vehicle) (not shown). The engine 20 includes a crankshaft 21 as an output shaft, one end side (left side in the figure) of the crankshaft 21 is provided inside the engine 20, and the other end side (right side in the figure) of the crankshaft 21 is a drive mechanism 30. It is extended toward the. The engine 20 is provided with a starter motor 22, and the engine 20 can be started by supplying a drive current to rotationally drive the starter motor 22.

  The drive mechanism 30 includes a casing 31 that forms an outline thereof. Inside the casing 31, there are a torque converter 32, a planetary gear mechanism 33, a first clutch 34, a continuously variable transmission (transmission) 35, a motor generator 36, a second clutch 37, a differential gear 38, and front and rear wheel power distribution mechanisms 39. Is provided.

  The torque converter 32 includes a pump impeller 32a and a turbine runner 32b, and a stator 32c is provided between the pump impeller 32a and the turbine runner 32b. Oil having a relatively low viscosity (not shown) circulates inside the torque converter 32, and the inertial force of the oil accompanying the rotation of the pump impeller 32a is transmitted to the turbine runner 32b. The output shaft 32d fixed to the runner 32b rotates. The other end side of the crankshaft 21 is connected to the pump impeller 32a, and the other end side of the output shaft 32d is connected to the sun gear 33a of the planetary gear mechanism 33.

  The planetary gear mechanism 33 includes a sun gear 33a, a plurality of (for example, three) pinion gears 33b, a carrier 33c that supports each pinion gear 33b, and a ring gear 33d. Each pinion gear 33b meshes with the sun gear 33a and rolls around the sun gear 33a. Further, a ring gear 33d is engaged with each pinion gear 33b, and the ring gear 33d rotates around each pinion gear 33b.

  One end side of the carrier 33c is connected to the output shaft 32d via the carrier clutch 34a so as to be fastened or released. The other end of the carrier 33c is connected to the first shaft 35a of the continuously variable transmission 35 so as to be integrally rotatable. The ring gear 33d is connected to the casing 31 via the ring gear clutch 34b so as to be fastened or released. The first clutch 34 is formed by a carrier clutch 34 a and a ring gear clutch 34 b, and the first clutch 34 is provided between the engine 20 and the continuously variable transmission 35. The first clutch 34 fastens or opens a power transmission path between the engine 20 and the continuously variable transmission 35, and a first clutch unit 52a (not shown) having a drive mechanism (not shown) such as an electromagnetic solenoid. 2).

  Here, when both the carrier clutch 34a and the ring gear clutch 34b are released, the shift position of the continuously variable transmission 35 is neutral. Further, when the carrier clutch 34a is engaged and the ring gear clutch 34b is released, the sun gear 33a, each pinion gear 33b, and the carrier 33c rotate integrally, and the shift position of the continuously variable transmission 35 moves forward. On the contrary, when the carrier clutch 34a is released and the ring gear clutch 34b is engaged, the shift position of the continuously variable transmission 35 is reverse.

  The continuously variable transmission 35 is provided between the engine 20 and the motor generator 36 and shifts the rotational speed of the engine 20. The continuously variable transmission 35 includes a primary pulley 40 and a secondary pulley 41, and a chain belt 42 is wound between the pulleys 40 and 41. The primary pulley 40 is provided on the first shaft 35a, and the primary pulley 40 includes a fixed sheave 40a fixed to the first shaft 35a and a movable sheave 40b movable in the axial direction of the first shaft 35a. A primary cylinder 40c is provided on the other end side of the movable sheave 40b, and the movable sheave 40b approaches or separates from the fixed sheave 40a by supplying and discharging hydraulic pressure to and from the primary cylinder 40c. Thereby, the pressing force with respect to the chain belt 42 between the fixed sheave 40a and the movable sheave 40b can be controlled, and the winding diameter of the chain belt 42 with respect to the primary pulley 40 can be changed.

  The continuously variable transmission 35 includes a second shaft 35b parallel to the first shaft 35a, and a secondary pulley 41 is provided on the second shaft 35b. The secondary pulley 41 includes a fixed sheave 41a fixed to the second shaft 35b and a movable sheave 41b movable in the axial direction of the second shaft 35b. A secondary cylinder 41c is provided at one end of the movable sheave 41b, and the pressure applied to the chain belt 42 by the movable sheave 41b is controlled by supplying and discharging hydraulic pressure to and from the secondary cylinder 41c. Thereby, the slip resistance etc. with respect to the secondary pulley 41 of the chain belt 42 are adjusted, and the rotation speed of the 1st shaft 35a and the 2nd shaft 35b can be controlled.

  For example, when the hybrid vehicle starts, the winding diameter of the chain belt 42 with respect to the secondary pulley 41 is increased by increasing the hydraulic pressure in the secondary cylinder 41c. Further, when the hybrid vehicle is traveling at a high speed, the winding diameter of the chain belt 42 with respect to the secondary pulley 41 is reduced by lowering the hydraulic pressure in the secondary cylinder 41c. Here, the hydraulic pressure in the primary cylinder 40c and the secondary cylinder 41c is controlled by a hydraulic drive mechanism (not shown) controlled by the TCU 52 (see FIG. 2).

  A motor generator 36 that functions as a drive motor and a generator is provided on a third shaft 43 provided in parallel with the second shaft 35b. A differential gear 38 is provided on one end side of the third shaft 43, and a pair of left and right front wheels (not shown) as drive wheels are connected to the differential gear 38 via a drive shaft. Further, a fourth shaft 45 is provided on the other end side of the third shaft 43 via a gear mechanism 44. The fourth shaft 45 is provided with left and right driving wheels via a front and rear wheel power distribution mechanism 39 and a drive shaft. A pair of rear wheels (not shown) are connected. That is, the hybrid vehicle in the present embodiment employs a four-wheel drive vehicle in which all wheels are drive wheels. Here, the front and rear wheel power distribution mechanism 39 is configured to optimally distribute torque to each front wheel and each rear wheel, for example, in order to stabilize the traveling state.

  A gear mechanism 46 is provided between the second shaft 35 b and the third shaft 43, and the gear mechanism 46 is fixed to the rotor 36 a of the motor generator 36. A second clutch 37 is provided between the gear mechanism 46 and the third shaft 43, that is, between the motor generator 36 and the front and rear wheels. The second clutch 37 is connected to the motor generator 36 and the third shaft 43 ( The transmission path between the front and rear wheels is fastened or released. Here, the second clutch 37 is controlled by a second clutch unit 52b (see FIG. 2) provided with a drive mechanism (not shown) such as an electromagnetic solenoid.

  As shown in FIG. 2, the hybrid drive device 10 includes a drive circuit 50 as an electrical system. The drive circuit 50 includes an ECU (engine control unit) 51, a TCU (transmission control unit) 52, an inverter 53, a B / TCU (battery control unit) 54, and a HEVCU (hybrid vehicle control unit) 55 as control units in the present invention. I have. Each control unit 51-55 is electrically connected to a CAN communication line (Controller Area Network) 56 constructed in the hybrid vehicle, and exchanges information with each other between the control units 51-55. An accelerator switch 57 is electrically connected to the CAN communication line 56. From the accelerator switch 57, accelerator operation information (detection signal) by the driver is sent to the control units 51 to 55 via the CAN communication line 56.

  The ECU 51 controls a fuel injection device, an ignition device, a throttle valve, and the like (not shown) of the engine 20 to control the operating state of the engine 20. A crank angle sensor 51 a is electrically connected to the ECU 51, and the rotation state of the crankshaft 21 is fed back to the ECU 51. The ECU 51 calculates the fuel injection amount, ignition timing, throttle valve opening, etc. of the engine 20 based on the detection signal input from the crank angle sensor 51a, information transmitted from the CAN communication line 56, etc. The state is controlled.

  The TCU 52 controls the hydraulic drive mechanism (not shown) of the continuously variable transmission 35, the first clutch unit 52a, the second clutch unit 52b, and the like. The TCU 52 includes a first rotation speed sensor 52c that detects the rotation speed of the first shaft 35a of the continuously variable transmission 35, and a second rotation speed that detects the rotation speed of the third shaft 43, that is, the rotation speed (vehicle speed) of the drive wheels. The rotation speed sensor 52d is electrically connected. Here, the 2nd rotation speed sensor 52d comprises the vehicle speed detection means in this invention.

  The TCU 52 is based on detection signals (vehicle speed signals) input from the rotational speed sensors 52c and 52d, information transmitted from the CAN communication line 56, and the like, and the target gear ratio, the target primary cylinder pressure, the target of the continuously variable transmission 35, etc. Calculate secondary cylinder pressure, etc. The gear ratio of the continuously variable transmission 35 and the engagement / release of the clutches 34 and 37 by the clutch units 52a and 52b are controlled.

  The inverter 53 converts the electric power from the in-vehicle power storage unit 58 that is a high-voltage battery into three phases to generate a drive current, and supplies the generated drive current to the motor generator 36. Here, the in-vehicle power storage unit 58 employs a lithium ion secondary battery. A third rotation speed sensor 53 a that detects the rotation speed of the motor generator 36 is electrically connected to the inverter 53, and the rotation state of the motor generator 36 is fed back to the inverter 53. The inverter 53 controls the motor generator 36 based on a detection signal input from the third rotation speed sensor 53a, information transmitted from the CAN communication line 56, and the like.

  The B / TCU 54 calculates the remaining energy (SOC) of the in-vehicle power storage unit 58 and monitors the charge state of the in-vehicle power storage unit 58. Information on the remaining energy amount calculated by the B / TCU 54, information indicating the charging state of the in-vehicle power storage unit 58, and the like are transmitted to the CAN communication line 56 and transmitted to other control units.

  The HEVCU 55 comprehensively controls the entire drive system of the hybrid vehicle, and various information and the like are transmitted to the HEVCU 55 from other control units via the CAN communication line 56. The HEVCU 55 is electrically connected to a mode instruction switch 55a that is turned on and off by the driver, and the mode instruction switch 55a in the present embodiment is a cruise control switch.

  Next, the operation content of the hybrid drive apparatus 10 formed as described above will be described in detail with reference to the drawings.

  3 is a main flowchart showing the operation contents of the hybrid drive apparatus of FIG. 1, FIG. 4 is a sub-flow chart showing the operation contents of acceleration control in the main flowchart of FIG. 3, and FIG. 5 is a deceleration chart in the main flowchart of FIG. Each of the sub-flow charts showing the operation contents of control is shown.

  In hybrid drive device 10 according to the present embodiment, it is a precondition for executing the inertial traveling mode that the hybrid vehicle is in a cruise control (constant speed traveling control) state.

  As shown in FIG. 3, when an ignition switch (not shown) is turned on in step S1, vehicle speed V of the hybrid vehicle is detected in subsequent step S2. Here, the vehicle speed V is obtained from the detection signal of the second rotation speed sensor 52 d that detects the rotation speed of the third shaft 43. However, when the second clutch 37 is in the engaged state, the vehicle speed V can also be obtained from the detection signal of the third rotation speed sensor 53a that detects the rotation speed of the motor generator 36.

  In step S3, it is determined whether or not the vehicle speed V is smaller than the first vehicle speed threshold value V1. If it is determined in step S3 that the vehicle speed V is smaller than the first vehicle speed threshold value V1 (yes determination), the process proceeds to step S20. In step S20, it is assumed that the hybrid vehicle is running normally (cruise control off state), and the cruise control flag F is set to “0”. On the other hand, when it is determined in step S3 that the vehicle speed V is equal to or higher than the first vehicle speed threshold value V1 (no determination), the process proceeds to step S4. Here, the first vehicle speed threshold value V1 constitutes a predetermined vehicle speed in the present invention.

  In step S4, based on the detection signal from the accelerator switch 57 (brake switch (not shown)), whether or not there is an accelerator operation (brake operation) by the driver, that is, whether or not the accelerator pedal (brake pedal) is depressed. Determine whether or not. If it is determined in step S4 that there is an accelerator operation (brake operation) (yes determination), the process proceeds to step S20. On the other hand, if it is determined in step S4 that there is no accelerator operation (brake operation) (no determination), the process proceeds to step S5.

  In step S5, it is determined whether or not the mode instruction switch (cruise control switch) 55a is turned off. If it is determined in step S5 that the mode instruction switch 55a has been turned off (yes determination), the process proceeds to step S20 in order to place the hybrid vehicle in a normal traveling state in the same manner as in steps S3 and S4. When it is determined in step S5 that the mode instruction switch 55a has been turned on (no determination), the process proceeds to step S6 to determine whether or not the cruise control flag F is “1” or more.

  When it is determined in step S6 that the cruise control flag F is smaller than “1” (no determination), it is determined that the cruise control is not being performed in the previous control cycle, and the process proceeds to step S17. In step S17, it is determined whether or not the mode instruction switch 55a is turned on. When it is determined in step S17 that the mode instruction switch 55a is not turned on (no determination), the process proceeds to step S16 and RETURN processing is performed. If it is determined in step S17 that the mode instruction switch 55a has been turned on (yes determination), the process proceeds to step S18, and a second vehicle speed threshold value V2 that is a reference vehicle speed during cruise control is set based on the vehicle speed V. A vehicle speed lower limit value Vmin and a vehicle speed upper limit value Vmax (set vehicle speed range Vmin to Vmax) sandwiching the second vehicle speed threshold value V2 are set. Here, the second vehicle speed threshold value V2 is set to a value larger than the first vehicle speed threshold value V1 (V2> V1).

  In the subsequent step S19, the hybrid vehicle starts cruise control, and sets the cruise control flag F to “1”. Here, the cruise control according to the present embodiment is executed by turning on the mode instruction switch 55a, and is ended by depressing the accelerator pedal (brake pedal) again or turning off the mode instruction switch 55a. .

  If it is determined in step S6 that the cruise control flag F is “1” or more (yes determination), that is, if it is determined that cruise control is being performed, the process proceeds to step S7, where the cruise control flag F is “2”. It is determined whether or not there is. Here, the case where the cruise control flag F is “2” means that the hybrid vehicle does not travel by the driving force of the engine 20 or the motor generator 36 but travels by its own inertia force (glider traveling), That is, it means that it is an inertia traveling mode. The inertia traveling mode referred to here constitutes the first inertia traveling mode in the present invention.

  If it is determined in step S7 that the cruise control flag F is “2” (yes determination), the process proceeds to step S14. If it is determined in step S7 that the cruise control flag F is not "2" (no determination), the routine proceeds to step S8 and normal cruise control is executed. Here, the normal cruise control is a constant speed running mode in which the hybrid vehicle is driven by driving the engine 20, and specifically, both the first clutch 34 and the second clutch 37 are both engaged, and the engine The vehicle speed V is controlled to be maintained at a constant speed by driving 20.

  In the constant speed running mode, the counter process in step S9 and the counter comparison process in step S10 are executed. If it is determined in step S10 that the hybrid vehicle has not traveled for the predetermined time T1 or longer (no determination), the process proceeds to step S16 and RETURN processing is performed. If it is determined in step S10 that the hybrid vehicle has traveled for a predetermined time T1 or more (yes determination), the process proceeds to step S11, the counter value T indicating the travel time is reset (T = 0), and then cruise control is performed in step S12. The flag F is set to “2”.

  In step S13, the inertial running mode, that is, the release of the second clutch 37 and the fuel cut to the engine 20 (engine stop) are executed. Thereafter, the vehicle speed V is compared in steps S14 and S15. When the vehicle speed V is Vmin ≦ V ≦ Vmax, that is, when the vehicle speed V is within the set vehicle speed range Vmin to Vmax (steps S14 and S15). In the case where both are determined to be no), the process proceeds to step S16, where RETURN processing is performed, and the inertial running mode is continuously executed.

  If Vmin> V is satisfied in step S14, that is, if the vehicle speed V deviates from the set vehicle speed range Vmin to Vmax and becomes low (yes determination), the process proceeds to step S22 and the vehicle speed V is set to the set vehicle speed range Vmin to Vmin. Execute acceleration control to keep Vmax. On the other hand, if Vmax <V is established in step S15, that is, if the vehicle speed V deviates from the set vehicle speed range Vmin to Vmax and becomes high (yes determination), the process proceeds to step S21 and the vehicle speed V is set to the set vehicle speed range. Execute deceleration control to keep Vmin to Vmax.

  Next, the acceleration control (subflow) in step S22 will be described with reference to FIG. When acceleration control is executed in step S201, the motor generator 36 is turned on and driven to rotate in the subsequent step S202. Here, the motor generator 36 is rotationally driven based on the detection signal of the second rotation speed sensor 52d and the detection signal of the third rotation speed sensor 53a, and the rotation speed of the motor generator 36 and the rotation speed of each drive wheel are synchronized. .

  In step S203, the second clutch 37 is engaged and the motor generator 36 is rotationally driven (power running drive) under the state where the rotational speed of the motor generator 36 and the rotational speed of each drive wheel are synchronized. Subsequent steps S204 to S206 show the same conditions as steps S3 to S5 in FIG. If at least one of step S204 to step S206 is established (yes determination), the cruise control flag F is set to “0” in step S213, and then the process proceeds to step S211 to end the acceleration control.

  In step S207, it is determined whether or not the vehicle speed V has reached or exceeded the second vehicle speed threshold value V2. If it is determined in step S207 that the vehicle speed V has reached or exceeded the second vehicle speed threshold value V2 (yes determination), the process proceeds to step S212, the counter value K is reset (K = 0), and the acceleration control is terminated in step S211. To do. Here, the counter value K indicates the vehicle speed return time by the power running drive of the motor generator 36. If it is determined in step S207 that the vehicle speed V is smaller than the second vehicle speed threshold value V2 (no determination), timer counting is performed in subsequent steps S208 and S209.

  If it is determined in step S209 that the counter value K is less than the predetermined time K1 (no determination), the process returns to step S204. If it is determined in step S209 that the counter value K is equal to or greater than the predetermined time K1 (yes determination), the vehicle speed V does not return to the second vehicle speed threshold V2 or higher even after the predetermined time K1 has elapsed, and the motor generator It is assumed that the speed increase of the hybrid vehicle cannot be expected only by the power running drive of 36, the cruise control flag F is set to “1” in the subsequent step S210, the process proceeds to step S211 and the acceleration control is terminated.

  Next, the deceleration control (subflow) in step S21 will be described with reference to FIG. When deceleration control is executed in step S301, the motor generator 36 is turned on and driven to rotate in the subsequent step S302. Here, the motor generator 36 is rotationally driven based on the detection signal of the second rotation speed sensor 52d and the detection signal of the third rotation speed sensor 53a, and the rotation speed of the motor generator 36 and the rotation speed of each drive wheel are synchronized. .

  In step S303, the second clutch 37 is engaged under the state where the rotation speed of the motor generator 36 and the rotation speed of each drive wheel are synchronized, and the motor generator 36 is driven as a generator (regenerative drive). . Subsequent steps S304 to S306 indicate the cruise control end determination conditions with the same processing contents as steps S3 to S5 in FIG. If at least one of steps S304 to S306 is established (yes determination), the cruise control flag F is set to “0” in step S313, and then the process proceeds to step S311 to end the deceleration control.

  In step S307, it is determined whether or not the vehicle speed V is equal to or lower than the second vehicle speed threshold value V2. If it is determined in step S307 that the vehicle speed V has become equal to or lower than the second vehicle speed threshold value V2 (yes determination), the process proceeds to step S312 and the counter value K is reset (K = 0), and the deceleration control is terminated in step S311. To do. Here, the counter value K indicates the vehicle speed recovery time by regenerative driving of the motor generator 36. If it is determined in step S307 that the vehicle speed V is greater than the second vehicle speed threshold value V2 (no determination), timer counting is performed in subsequent steps S308 and S309.

  If it is determined in step S309 that the counter value K is less than the predetermined time K1 (no determination), the process returns to step S304. If it is determined in step S309 that the counter value K is greater than or equal to the predetermined time K1 (yes determination), the vehicle speed V does not return to the second vehicle speed threshold V2 or less even after the predetermined time K1 has elapsed, and the motor generator It is assumed that deceleration of the hybrid vehicle cannot be expected with only the 36 regenerative drive, and in subsequent step S310, the cruise control flag F is set to “1”, and the process proceeds to step S311 to end the deceleration control.

  Here, in the acceleration control and the deceleration control shown in FIGS. 4 and 5, when it is difficult to keep the vehicle speed V within the set vehicle speed range Vmin to Vmax due to the power running drive and the regenerative drive of the motor generator 36, step S210 and step S210 are performed. In S310, the cruise control flag F is set to “1”. Therefore, after that, returning to the main flowchart shown in FIG. 3, normal cruise control is executed in step S8.

  In this way, the hybrid drive device 10 executes the inertial running mode as much as possible during cruise control. Further, when the vehicle speed V deviates from the set vehicle speed range Vmin to Vmax, the vehicle speed V is adjusted to be within the set vehicle speed range Vmin to Vmax by the power running drive and the regenerative drive of the motor generator 36. Therefore, the opportunity for starting the engine 20 can be reduced. Further, as a condition for switching to the inertial running mode, as shown in step S9 and step S10 in FIG. 3, since the normal cruise control is performed for a predetermined time T1 or more, the engine 20 is frequently started and stopped repeatedly. It is possible to make it difficult for the driver and passengers to feel uncomfortable and uncomfortable.

  Next, a specific operation of the hybrid drive device 10 will be described in detail with reference to the drawings.

  FIG. 6 is a timing chart showing the specific operation of the hybrid drive apparatus of FIG. 1, and FIG. 7 is a timing chart (showing air conditioner SW, SOC display) showing the specific operation of the hybrid drive apparatus of FIG. Represents each.

[Time (1)-Time (2)]
This shows a case where the hybrid vehicle is running normally and is in an accelerated state. The mode instruction switch 55a is in an off state, and both the first clutch 34 and the second clutch 37 are in an engaged state. The hybrid vehicle is gradually accelerated by the rotational drive (driving force) of only the engine 20. The gear ratio of the continuously variable transmission 35 is controlled in conjunction with the engagement / release of the first clutch 34. In FIG. 7, the air conditioner switch (not shown) is in an on state, and since it has just started accelerating in this state, the remaining energy amount (SOC) of the in-vehicle power storage unit 58 changes in a substantially constant state. Yes. Here, the motor generator 36 can also be rotationally driven to assist the driving force of the engine 20 with both the first clutch 34 and the second clutch 37 engaged. Such a travel mode in which the vehicle travels with at least the driving force of the engine 20 constitutes the normal travel mode in the present invention.

[Time (2)-Time (3)]
This shows a case where the vehicle speed V increases to some extent and the driver turns on the mode instruction switch 55a to execute normal cruise control. At this time, both the first clutch 34 and the second clutch 37 are still engaged. At this time, the engine 20 and the continuously variable transmission 35 are automatically controlled so that the vehicle speed V falls within a set vehicle speed range Vmin to Vmax sandwiching the second vehicle speed threshold value V2.

[Time (3)-Time (4)]
A state in which a predetermined time T1 (time (2) to time (3)) has elapsed from the start of normal cruise control and the vehicle has shifted to the inertia traveling mode (first inertia traveling mode) is shown. Both the first clutch 34 and the second clutch 37 are released, and the fuel cut to the engine 20 (engine stop) is executed. At this time, the gradient of the road surface is flat, but the vehicle speed V gradually decreases due to the running resistance of the hybrid vehicle. In FIG. 7, only the fuel cut is executed without stopping the engine 20, and the engine 20 generates the minimum engine torque necessary for driving the air conditioner. In addition, the SOC of the in-vehicle power storage unit 58 is gradually decreased due to the driving of the air conditioner and other in-vehicle devices.

[Time (4)-Time (5)]
A state in which the vehicle speed V deviates from the set vehicle speed range Vmin to Vmax and falls below the vehicle speed lower limit value Vmin is shown. Here, acceleration control (see FIG. 4) is executed, and the second clutch 37 is engaged in a state where the rotation speed of the motor generator 36 and the rotation speed of each drive wheel are synchronized. Thereafter, the motor generator 36 is driven by powering. The vehicle speed V is increased (returned) by the power running drive of the motor generator 36 and approaches the second vehicle speed threshold value V2. At this time, as shown in FIG. 7, the SOC of the in-vehicle power storage unit 58 is greatly reduced due to the power running driving of the motor generator 36. Here, the 1st clutch 34 is maintaining the open state. Such a travel mode in which the first clutch 34 is disengaged and the second clutch 37 is engaged and travels by powering drive (driving force) of the motor generator 36 constitutes the motor travel mode in the present invention.

[Time (5)-Time (6)]
The state in which the second clutch 37 is released and the motor generator 36 is stopped by the return of the vehicle speed V is shown. As a result, the hybrid vehicle starts inertial running again. In addition, the gradient resistance of the hybrid vehicle decreases during the period from time (5) to time (6), that is, the hybrid vehicle approaches a downhill, and the vehicle speed V gradually increases (accelerates) by traveling on the downhill. In FIG. 7, the air conditioner driving is continued, the SOC of the in-vehicle power storage unit 58 is equal to or lower than a predetermined value (not shown), and so on, with the second clutch 37 being released. The control is switched so that one clutch 34 is engaged and the motor generator 36 is regeneratively driven. Then, the engine torque of the engine 20 is increased, thereby continuing the air-conditioner driving and charging the in-vehicle power storage unit 58, and the SOC gradually increases. Here, the inertial running mode in time (5) to time (6) shown in FIG. 7 constitutes the second inertial running mode in the present invention.

[Time (6)-Time (7)]
The hybrid vehicle travels downhill and enters an acceleration state, and the vehicle speed V deviates from the set vehicle speed range Vmin to Vmax and exceeds the vehicle speed upper limit value Vmax. Here, deceleration control (see FIG. 5) is executed, and the second clutch 37 is engaged in a state where the rotation speed of the motor generator 36 and the rotation speed of each drive wheel are synchronized. Thereafter, the motor generator 36 is regeneratively driven. Accordingly, the vehicle speed V decreases (returns) due to the regenerative drive of the motor generator 36, and approaches the second vehicle speed threshold value V2. In FIG. 7, the air conditioner switch is turned off, and the charging efficiency of the in-vehicle power storage unit 58 is increased. In addition, after time (6), since the air conditioner switch is in an off state, FIGS. 6 and 7 are the same timing chart. Here, the 1st clutch 34 is maintaining the open state. Such a travel mode in which the second clutch 37 is engaged while the first clutch 34 is released and the motor generator 36 travels by regenerative driving (driving force) constitutes the motor travel mode in the present invention.

  As described above, in the time (4) to the time (7), since the SOC of the in-vehicle power storage unit 58 is equal to or lower than a predetermined value (not shown) in the time (5) to the time (6), the motor travel mode (Power running drive), second inertia traveling mode, and motor traveling mode (regenerative drive) are executed alternately.

[Time (7)-Time (8)]
The hybrid vehicle continuously travels on a downhill by coasting and accelerates again. At this time, the second clutch 37 is released, and the engine 20 and the motor generator 36 are stopped. Here, as shown in FIG. 7, the SOC gradually decreases, but this is due to the consumption of a high-voltage battery by driving other in-vehicle devices (for example, power steering pumps, headlights, etc.) other than the air conditioner. Is.

[Time (8)-Time (9)]
The same state as time (6) to time (7) is shown.

[Time (9)-Time (10)]
The vehicle speed V of the hybrid vehicle is stable, the vehicle speed V is within the set vehicle speed range Vmin to Vmax, and the vehicle is returned to normal cruise control. At this time, both the first clutch 34 and the second clutch 37 are engaged. Here, the second clutch 37 is in a pre-engaged state from time (8) to time (9). Therefore, the first clutch 34 is engaged after synchronizing the rotation speed. Yes. That is, the engine 20 is started by the starter motor 22 and driven to rotate at a predetermined engine torque. The engine torque generated by the engine 20 is taken into consideration, and the rotational speed (motor torque) of the motor generator 36 is controlled. The gear ratio (speed ratio) of the step transmission 35 is controlled. Thereafter, the first clutch 34 is moved under a state in which the input side of the first clutch 34, that is, the rotational speed of the output shaft 32d is synchronized with the output side of the first clutch 34, that is, the rotational speed of the first shaft 35a. Conclude. Thereby, the charging operation of the in-vehicle power storage unit 58 by the regenerative drive of the motor generator 36 and the traveling on the uphill of the hybrid vehicle (where the gradient resistance gradually increases) can be performed smoothly.

[Time (10)-Time (11)]
The same state as time (3) to time (4) is shown. However, in FIG. 7, time (3) to time (4) are different in that the air conditioner switch is off and the rotational drive of the engine 20 is stopped.

[After time (11)]
A case is shown in which the normal cruise control is terminated, for example, when the driver performs a brake operation. After time (11), both the first clutch 34 and the second clutch 37 are engaged, and the engine 20 is started, so that the hybrid vehicle enters a normal running state.

  The hybrid drive apparatus 10 according to the present embodiment is configured to start the engine 20 by the starter motor 22 (see FIG. 1). Hereinafter, a case will be described in which the engine 20 is started by the motor generator 36 so that the starter motor 22 can be started less frequently.

  The timing for starting the engine 20 includes the “normal traveling mode” in the time (1) to the time (2) and the “second inertia traveling mode” in the time (5) to the time (6) shown in FIGS. The start time is mentioned. When starting each of these travel modes, first, the second clutch 37 is released, and the rotational speed of the motor generator 36 is made substantially zero under this state. Thereafter, the first clutch 34 is engaged under the state where the rotational speed of the motor generator 36 is substantially zero. Then, the engine 20 is started by driving the motor generator 36 with a predetermined motor torque. Thereby, the starter motor 22 can reduce the start opportunity of the engine 20, and can protect a low voltage battery (12V power source) (not shown), for example. Further, the life of the starter motor 22 can be extended.

  As described above in detail, according to the hybrid drive device 10 according to the present embodiment, the continuously variable transmission 35 that changes the rotational speed of the engine 20 is provided between the engine 20 and the motor generator 36. A first clutch 34 for fastening or releasing a power transmission path between the engine 20 and the continuously variable transmission 35 is provided between the continuously variable transmission 35 and the motor generator 36 between the motor generator 36 and the drive wheels. A second clutch 37 for fastening or releasing a power transmission path with the drive wheels is provided, and the control units 51 to 55 cooperate with each other to connect the first clutch 34 and the second clutch 37 based on the vehicle speed V. Both of them are engaged, and at least the normal traveling mode in which the vehicle is driven by the rotational drive of the engine 20 and the second clutch 37 are engaged while the first clutch 34 is released. Then, the motor traveling mode in which the vehicle is driven by the rotation of the motor generator 36 and the first inertia traveling mode in which the second clutch 37 is disengaged and the hybrid vehicle is driven by the inertial force are switched.

  As a result, the driving force required for traveling of the hybrid vehicle according to the vehicle speed V of the hybrid vehicle can be obtained from the inertial force of the hybrid vehicle, the driving force of the motor generator 36, and the driving force of the engine 20. Since the second clutch 37 is provided closer to the driving wheel (downstream side) than the engine 20, the first clutch 34, the continuously variable transmission 35, and the motor generator 36, the continuously variable transmission located upstream of the second clutch 37. The drive wheels can be smoothly rotated without being affected by the friction (friction resistance) of the machine 35 and the like. Further, it is not necessary to supply the transmission hydraulic pressure to the transmission as before. Therefore, energy efficiency can be further improved and low fuel consumption can be realized.

  Further, according to the hybrid drive apparatus 10 according to the present embodiment, the control units 51 to 55 cooperate with each other under the state in which the second clutch 37 is released during execution of the first inertia traveling mode. Since the second inertia traveling mode in which the first clutch 34 is engaged and the engine 20 is driven to charge the in-vehicle power storage unit 58 with the motor generator 36 is executed, the driving force of the engine 20 is not transmitted to the drive wheels, and the motor Only the generator 36 can be driven efficiently as a generator. Further, since the driving force of the engine 20 is not transmitted to the driving wheels, the vehicle speed V does not decelerate or accelerate, and the hybrid vehicle can continue to travel smoothly and inertially.

  Furthermore, according to the hybrid drive device 10 according to the present embodiment, the control units 51 to 55 cooperate to each other when the remaining energy amount (SOC) of the in-vehicle power storage unit 58 becomes a predetermined value or less. The second inertia traveling mode and the motor traveling mode can be executed alternately.

  Moreover, according to the hybrid drive device 10 according to the present embodiment, the engine 20 is started by the starter motor 22, and each of the control units 51 to 55 cooperates to engage the first clutch 34 when the motor generator is engaged. 36 and the speed ratio of the continuously variable transmission 35 are controlled to synchronize the rotational speeds of the input side and the output side of the first clutch 34, so that vibration or the like is generated when the first clutch 34 is engaged. Can be prevented.

  Furthermore, according to the hybrid drive device 10 according to the present embodiment, the engine 20 is started by the motor generator 36, and the control units 51 to 55 cooperate with each other in the normal traveling mode or the second inertia traveling mode. When the engine is started, the second clutch 37 is disengaged to make the rotation speed of the motor generator 36 substantially zero, and then the first clutch 34 is engaged to drive the motor generator 36 to rotate.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the winding type continuously variable transmission 35 having the chain belt 42 is adopted as the transmission. However, the present invention is not limited to this, and the toroidal continuously variable transmission is used. Other transmissions such as a stepped automatic transmission or the like can also be employed.

  Moreover, in the said embodiment, although the four-wheel drive vehicle in which all the wheels became the drive wheel was shown as an example, this invention is not limited to this, It is applied also to a front-wheel drive vehicle and a rear-wheel drive vehicle. Can do.

10 Hybrid drive 20 Engine (Internal combustion engine)
22 starter motor 34 first clutch 35 continuously variable transmission (transmission)
36 Motor generator 37 Second clutch 51 ECU (control unit)
52 TCU (Control Unit)
52d Second rotational speed sensor (vehicle speed detection means)
53 Inverter (control unit)
54 B / TCU (control unit)
55 HEVCU (control unit)
57 Accelerator switch 58 On-vehicle storage battery
V vehicle speed
V1 First vehicle speed threshold (predetermined vehicle speed)

Claims (5)

A hybrid drive device having an internal combustion engine and a motor generator,
Vehicle speed detecting means for detecting the vehicle speed of the vehicle;
A control unit to which a vehicle speed signal from the vehicle speed detection means is input;
A transmission that is provided between the internal combustion engine and the motor generator and that changes the rotational speed of the internal combustion engine;
A first clutch provided between the internal combustion engine and the transmission for fastening or releasing a power transmission path between the internal combustion engine and the transmission;
A second clutch provided between the motor generator and the drive wheel, for fastening or releasing a power transmission path between the motor generator and the drive wheel;
The control unit is based on the vehicle speed,
A normal travel mode in which both the first clutch and the second clutch are engaged, and the vehicle travels at least by the rotational drive of the internal combustion engine;
A motor travel mode in which the second clutch is engaged while the first clutch is disengaged and the motor generator travels by rotational driving;
A hybrid drive apparatus that switches between a first inertia traveling mode in which the second clutch is released and the vehicle travels by inertia force.   2. The hybrid drive apparatus according to claim 1, wherein the control unit engages the first clutch with the second clutch released while the first inertia traveling mode is being executed, and drives the internal combustion engine. And a second inertial running mode in which the motor generator is used to charge the in-vehicle power storage unit.   3. The hybrid drive device according to claim 2, wherein the control unit alternately executes the second inertia traveling mode and the motor traveling mode when a remaining energy amount of the in-vehicle power storage unit becomes a predetermined value or less. A hybrid drive device characterized by that.   4. The hybrid drive device according to claim 1, wherein the internal combustion engine is started by a starter motor, and the control unit engages with the rotational speed of the motor generator when the first clutch is engaged. A hybrid drive apparatus that controls a transmission ratio of a transmission and synchronizes rotation speeds of an input side and an output side of the first clutch.   4. The hybrid drive apparatus according to claim 1, wherein the internal combustion engine is started by the motor generator, and the control unit starts the internal combustion engine in the normal traveling mode or the second inertia traveling mode. In this case, the hybrid drive apparatus is characterized in that after the second clutch is released and the rotational speed of the motor generator is made substantially zero, the first clutch is engaged and the motor generator is rotationally driven.

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