JP5758741B2 - Hybrid vehicle and control method of hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle including an internal combustion engine and an electric motor as drive sources.

  Conventionally, a control device for a hybrid vehicle including an electric motor and an internal combustion engine is known (Patent Document 1). When the hybrid vehicle control device detects that the vehicle is traveling on an uphill road that requires a large output when traveling only with the output of the electric motor, the internal combustion engine is started with the output of the electric motor. The control device engages the electric motor and the internal combustion engine by an engagement device such as a clutch at the time of start-up so that the output of the electric motor can be transmitted to the internal combustion engine. The control device increases the electric power supplied from the battery to the electric motor, thereby increasing the driving force for cranking the internal combustion engine (rotating the crankshaft of the internal combustion engine) in addition to the driving force for traveling. Output from the motor.

JP 2007-307995 A

  In general, it is known that the output voltage of a battery decreases due to a decrease in SOC (State of Charge) due to power consumption or the like. In general, the electric motor has a characteristic that the output decreases as the supplied voltage decreases. At this time, by increasing the current supplied to the electric motor, the output of the electric motor can be kept constant even when the supplied voltage decreases. In general, when the load increases rapidly, the battery has a characteristic that the output voltage temporarily decreases until the increased load decreases.

  When the internal combustion engine is started by the electric motor, the electric motor and the internal combustion engine are engaged by the engaging device, and the internal combustion engine is cranked by the output of the electric motor, and the load on the electric motor increases rapidly. As a result, the electric motor needs to keep running and crank the internal combustion engine. Thus, since the output of the electric motor increases rapidly, the electric power output from the battery, that is, the load on the battery is increased rapidly. For this reason, when the internal combustion engine is started, the output voltage of the battery temporarily decreases.

  The decrease in the output voltage is significantly reduced as the output power is increased before the load applied to the battery is rapidly increased. In other words, when the load suddenly increases, the output voltage of the battery decreases significantly as the load applied to the battery increases, that is, as the power to be output from the battery increases. At this time, in order to keep the output of the electric motor constant, it is necessary to increase the current supplied to the electric motor. However, the current that can be output from the battery has a maximum value, and current exceeding this value cannot be supplied from the battery to the electric motor. For this reason, when the current for compensating for the decrease in the output voltage of the battery exceeds the maximum current that can be supplied from the battery, the output of the electric motor decreases.

  However, in the hybrid vehicle control device disclosed in Patent Document 1, there is no description that considers a decrease in the SOC of the battery or a decrease in the output voltage of the battery due to a sudden increase in the load on the battery. For this reason, when the internal combustion engine is started, the output of the electric motor is reduced, so that the driving force for cranking the internal combustion engine is insufficient when the electric motor and the internal combustion engine are engaged by the engagement device. The driving force for running may be reduced, and the driver may feel uncomfortable.

  In view of such circumstances, an object of the present invention is to provide a hybrid vehicle that can start an internal combustion engine without affecting the traveling during traveling by the output of an electric motor.

A first aspect of the present invention includes an internal combustion engine and an electric motor as a prime mover, includes a battery that functions as a power source of the electric motor, and can transmit mechanical power output from the internal combustion engine and the electric motor to a vehicle propulsion shaft. The hybrid vehicle is an engagement device that switches an engagement state between the internal combustion engine and the electric motor, and outputs the output from the battery in comparison with the normal output characteristic of the battery or the normal output characteristic. Control means for controlling in accordance with a limited output characteristic that suppresses the operation , and the control means has stopped the operation of the internal combustion engine, and the engagement between the electric motor and the internal combustion engine by the engagement device is released. When the vehicle is running by the output of the electric motor, the electric motor and the internal combustion engine are engaged by the engagement device, and mechanical power from the electric motor When cranking the serial internal combustion engine, the control output of the battery in accordance with the limited output characteristic, combined with the output required for cranking the output and the internal combustion engine of the motor required for at least the travel of the vehicle The internal combustion engine is cranked and started when the required output is equal to or greater than the maximum output of the electric motor corresponding to the maximum output of the battery controlled by the limited output characteristics. .

  According to the first aspect of the present invention, when the internal combustion engine is cranked during traveling by the output of the electric motor, the electric motor and the internal combustion engine are engaged by the engagement device. Thereby, since the internal combustion engine is cranked by the electric motor, the output of the electric motor increases. However, at this time, the output of the battery is controlled according to the limited output characteristics. That is, at this time, the output is limited to be smaller than the normal output characteristics.

  For this reason, even when the load increases rapidly, the battery can suppress the overall load applied to the battery to be smaller than that in the case of normal output characteristics. Thereby, the fall of the output voltage of a battery is suppressed, and the fall of the output of an electric motor can be suppressed by extension. Therefore, the possibility that the output for cranking the internal combustion engine becomes insufficient when the electric motor and the internal combustion engine are engaged by the engagement device is reduced, and the travel is not affected during the travel by the output of the motor. The internal combustion engine can be started.

A second aspect of the present invention includes an internal combustion engine and an electric motor as a prime mover, a battery that functions as a power source for the electric motor, and can transmit mechanical power output from the internal combustion engine and the electric motor to a vehicle propulsion shaft. In the hybrid vehicle, mechanical power from the output shaft of the internal combustion engine and the output shaft of the electric motor is received by a first input shaft, and the vehicle propulsion shaft is shifted by any one of a plurality of shift stages. A first transmission mechanism capable of transmitting to the vehicle, and mechanical power from the output shaft of the internal combustion engine is received by the second input shaft, and is shifted by one of a plurality of shift stages and transmitted to the vehicle propulsion shaft. A second possible transmission mechanism, a first clutch capable of engaging the output shaft of the internal combustion engine and the first input shaft, and a first clutch capable of engaging the output shaft of the internal combustion engine and the second input shaft. Two clutches, the first transmission mechanism and the And a control means capable of controlling the selection of the gear position in the two-speed transmission mechanism and the engagement state of the first clutch and the second clutch, and the control means outputs the output from the battery to the normal state of the battery. Or a limited output characteristic that suppresses the output as compared with the normal output characteristic, and the control means has stopped the operation of the internal combustion engine, and the first clutch and the second clutch When the engagement between the electric motor and the internal combustion engine is released by releasing the engagement by the clutch and the vehicle is running by the output of the electric motor, the first clutch or the second clutch When the electric motor and the internal combustion engine are engaged with each other by the engagement, and the internal combustion engine is cranked by mechanical power from the electric motor, the limit output characteristics are obeyed. Controlling the output of the battery Te, at least request the output and the internal combustion engine of the motor required for the driving of the vehicle combined with the output required for cranking output is controlled by said limiting output characteristics The internal combustion engine is cranked and started when the maximum output of the electric motor corresponding to the maximum output of the battery is exceeded .

  According to the second aspect of the present invention, when cranking the internal combustion engine during traveling by the output of the electric motor, the electric motor and the internal combustion engine are engaged by the first clutch or the second clutch. At this time, by engaging the internal combustion engine and the first input shaft by the first clutch, the internal combustion engine and the electric motor are engaged via the vehicle propulsion shaft and the second input shaft. Further, the electric motor and the internal combustion engine are engaged by engaging the internal combustion engine and the second input shaft by the second clutch.

  Thereby, since the internal combustion engine is cranked by the electric motor, the output of the electric motor increases. However, at this time, the output of the battery is controlled according to the limited output characteristics. That is, at this time, the output is limited to be smaller than the normal output characteristics.

  For this reason, even when the load increases rapidly, the battery can suppress the overall load applied to the battery to be smaller than that in the case of normal output characteristics. Thereby, the fall of the output voltage of a battery is suppressed, and the fall of the output of an electric motor can be suppressed by extension. Therefore, the possibility that the output for cranking the internal combustion engine by the electric motor when the electric motor and the internal combustion engine are engaged by the first clutch or the second clutch is reduced is reduced. The internal combustion engine can be started without affecting the running.

  In the first and second aspects of the present invention, the control means may start controlling the output of the battery according to the limited output characteristics when the vehicle starts traveling only by the output of the electric motor. preferable. There is a possibility that the output from the battery to the electric motor may rapidly increase due to various external factors such as a sudden increase in the required driving force for the vehicle. In this case, if the output is not limited, the output voltage will drop significantly due to a sudden increase in output (a sudden increase in power consumption), and it will not be possible to increase the current by the required amount. There is a risk that it cannot be maintained. In view of the above, when starting to drive only the output of the motor, the output of the motor as described above can be maintained by starting to control the output of the battery in accordance with the limited output characteristics in advance. The possibility of disappearing is reduced.

  In the first and second aspects of the present invention, it is preferable that the control means predicts a voltage drop caused by the discharge of the battery and cranks and starts the internal combustion engine. Thereby, since the internal combustion engine can be started before the output of the electric motor necessary for traveling is reduced by predicting the voltage drop, the traveling is not affected.

  In the second aspect of the present invention, it is preferable that the control means selects the shift stage so that the output of the electric motor is minimized when cranking the internal combustion engine. As a result, the output for cranking the internal combustion engine is minimized, and the possibility that the output for traveling is reduced can be reduced.

A third aspect of the present invention includes an internal combustion engine and an electric motor as a prime mover, includes a battery that functions as a power source of the electric motor, and can transmit mechanical power output from the internal combustion engine and the electric motor to a vehicle propulsion shaft. A control method for a hybrid vehicle, wherein the hybrid vehicle receives mechanical power from an output shaft of the internal combustion engine and an output shaft of the electric motor by a first input shaft, and is controlled by any one of a plurality of shift stages. The first speed change mechanism capable of shifting and transmitting to the vehicle propulsion shaft and the mechanical power from the output shaft of the internal combustion engine are received by the second input shaft, and the speed is changed by any one of a plurality of speed stages. A second transmission mechanism capable of transmitting to the vehicle propulsion shaft, a first clutch capable of engaging the output shaft of the internal combustion engine and the first input shaft, the output shaft of the internal combustion engine and the second input The second shaft that can be engaged with the shaft And the engagement of the electric motor and the internal combustion engine is released by releasing the engagement by the first clutch and the second clutch, and during traveling by the output of the electric motor, An output limiting process for controlling the output of the battery by changing the normal output characteristic of the battery to a limited output characteristic that suppresses the output compared to the normal output characteristic, and at least the output of the electric motor required for traveling of the vehicle when the output of the internal combustion engine combined with the output required for cranking, the said limited output characteristic by more than the maximum output of the electric motor corresponding to the maximum and becomes the output of the battery being controlled and, A starting process for cranking and starting the internal combustion engine is performed.

  According to the third aspect of the present invention, since the internal combustion engine is started before the output of the electric motor necessary for traveling is reduced by the starting process, the internal combustion engine can be started without affecting the traveling. In addition, since the output of the battery is restricted at the time of starting, a decrease in the output voltage of the battery due to a sudden increase in the load of the battery due to the start of the internal combustion engine is suppressed. Thereby, the fall of the output of an electric motor is suppressed compared with the case of a normal output characteristic. Compared to the normal output characteristics, the overall load on the battery can be reduced.

  Thereby, the fall of the output voltage of a battery is suppressed, and the fall of the output of an electric motor can be suppressed by extension. Therefore, the possibility that the driving force for cranking the internal combustion engine by the output of the electric motor when the electric motor and the internal combustion engine are engaged by the first clutch or the second clutch is reduced is reduced, and the traveling by the driving force of the electric motor is reduced. The internal combustion engine can be started without affecting the traveling.

  Further, when starting the internal combustion engine by the starting process, the output from the battery is already limited by the output limiting process. For this reason, during driving, the normal output characteristic is changed to the limited output characteristic, and the output from the battery to the electric motor is reduced to reduce the output of the electric motor. .

The figure which shows the hybrid vehicle of this embodiment of this invention. The flowchart which shows the process sequence of the control process of the output of the battery which the control apparatus of the hybrid vehicle of this embodiment performs. The figure which shows the characteristic of the output with respect to SOC of a battery. It is a time chart which shows the time change of each parameter by control processing of a control device, (a) shows time change of the output voltage of a battery, and (b) shows the time change of the output of an electric motor. The figure which shows the hybrid vehicle of embodiment different from this embodiment.

  FIG. 1 is a diagram illustrating a hybrid vehicle according to an embodiment of the present invention that is applied to a hybrid vehicle. As shown in FIG. 1, a hybrid vehicle 1 includes an engine 10 as an internal combustion engine, an electric motor 11, a power storage device 2 that exchanges electric power with the electric motor 11, an automatic transmission 31, and an electronic control unit (ECU: Electronic). And a control device 21 comprising a Control Unit).

  The power storage device 2 is a nickel metal hydride battery or a lithium ion battery, and is configured as a rechargeable secondary battery.

  The control device 21 controls the engine 10, the electric motor 11, and the automatic transmission 31. The control device 21 includes a CPU 211 that executes various arithmetic processes, and a storage device (memory) 212 that includes a ROM and a RAM that store various arithmetic programs executed by the CPU 211, various tables, calculation results, and the like. Various electric signals representing the vehicle speed, the amount of operation of the accelerator pedal detected by the accelerator opening sensor 22, the number of revolutions of the engine 10, and the like are input, and a drive signal is output to the outside based on the calculation result and the like.

  The automatic transmission 31 includes an engine output shaft 32 to which the driving force (mechanical power) of the engine 10 is transmitted, and an output gear 33 that outputs power to the left and right front wheels as driving wheels via a differential gear (not shown). And six gear trains G2 to G7 having different gear ratios.

  The automatic transmission 31 also includes a first input shaft 34 that rotatably supports the drive gears 73, 75, and 77 of the odd-numbered gear trains G3, G5, and G7 that establish odd-numbered gears in the gear ratio order. The second input shaft 35 that rotatably supports the drive gears 72, 74, and 76 of the even-numbered gear trains G2, G4, and G6 that establish even-numbered gears in the gear ratio order, and the reverse gear GR. A reverse shaft 36 that freely supports the shaft is provided. The first input shaft 34 is disposed on the same axis as the engine output shaft 32, and the second input shaft 35 and the reverse shaft 36 are disposed in parallel with the first input shaft 34.

  The automatic transmission 31 includes an idle drive gear 80 rotatably supported by the first input shaft 34, a first idle driven gear 81 fixed to the idle shaft 37 and meshing with the idle drive gear 80, and a second An idle gear train GI including a second idle driven gear 82 fixed to the input shaft 35 and a third idle driven gear 83 fixed to the reverse shaft 36 and meshed with the first idle driven gear 81 is provided. The idle shaft 37 is arranged in parallel with the first input shaft 34.

  The automatic transmission 31 includes a first clutch 51 and a second clutch 52 that are hydraulically operated dry friction clutches or wet friction clutches. The first clutch 51 is switchable between an engaged state where the driving force of the engine 10 can be transmitted to the first input shaft 34 and an open state where the transmission is interrupted (a state where the engaged state is released). It is configured. Moreover, the 1st clutch 51 can adjust the driving force which can be transmitted by changing the amount of fastening in an engagement state.

  The second clutch 52 can be switched between an engaged state where the driving force of the engine 10 can be transmitted to the second input shaft 35 and an open state where the transmission is interrupted (a state where the engaged state is released). It is configured. Further, the second clutch 52 can adjust the driving force that can be transmitted by changing the amount of engagement in the engaged state. The engine output shaft 32 is connected to the second input shaft 35 via a first idle driven gear 81 and a second idle driven gear 82.

  Both clutches 51 and 52 are preferably operated by an electric actuator so that the state can be quickly switched. Both clutches 51 and 52 may be operated by a hydraulic actuator.

  In addition, the planetary gear mechanism 15 is disposed in the automatic transmission 31 so as to be coaxial with the engine output shaft 32. The planetary gear mechanism 15 is configured as a single pinion type including a sun gear 16, a ring gear 17, and a carrier 18 that rotatably and revolves a pinion 19 that meshes with the sun gear 16 and the ring gear 17. In this embodiment, the gear ratio of the planetary gear mechanism 15 (the number of teeth of the ring gear 17 / the number of teeth of the sun gear 16) is g.

  The sun gear 16 is fixed to the first input shaft 34. The carrier 18 is connected to the third speed drive gear 73 of the third speed gear train G3. The ring gear 17 is releasably fixed to the transmission case 7 by a lock mechanism 60.

  The lock mechanism 60 includes a brake mechanism that can be switched between a fixed state in which the ring gear 17 is fixed to the transmission case 7 and an open state in which the ring gear 17 is rotatable.

  The lock mechanism 60 is not limited to the synchromesh mechanism, and may be constituted by a dog clutch having no synchronization function, a wet multi-plate brake, a hub brake, a band brake, a one-way clutch, a two-way clutch, or the like. The planetary gear mechanism 15 is not limited to a single pinion type, and includes a sun gear, a ring gear, a carrier that rotatably and revolves a pair of pinions that mesh with each other and one meshes with the sun gear and the other meshes with the ring gear. You may comprise by the double pinion type which consists of. In this case, for example, the sun gear (first element) is fixed to the first input shaft 34, the ring gear (third element) is connected to the third speed drive gear 73 of the third speed gear train G3, and the carrier (second element). May be configured to be releasably fixed to the transmission case 7 by the lock mechanism 60.

  A hollow electric motor 11 is disposed outward of the planetary gear mechanism 15 in the radial direction. In other words, the planetary gear mechanism 15 is disposed inside the hollow electric motor 11. The electric motor 11 includes a stator 12 and a rotor 13.

  The electric motor 11 is controlled via the power drive unit 14 based on an instruction signal from the control device 21. The control device 21 generates the power drive unit 14 in a driving state in which the electric power of the power storage device 2 is consumed to drive the electric motor 11 and the rotational force of the rotor 13 is suppressed, and the generated electric power is transmitted via the power drive unit 14. It switches suitably to the regeneration state which charges the electrical storage apparatus 2.

  A first driven gear 41, a second driven gear 42, and a third driven gear 43 are fixed to the driven shaft 38 that supports the output gear 33. The first driven gear 41 meshes with the second speed drive gear 72 and the third speed drive gear 73. The second driven gear 42 meshes with the fourth speed drive gear 74 and the fifth speed drive gear 75. The third driven gear 43 meshes with the sixth speed drive gear 76 and the seventh speed drive gear 77.

  Thus, the driven gears of the second gear train G2 and the third gear train G3, the driven gear of the fourth gear train G4 and the fifth gear train G5, and the driven gear of the sixth gear train G6 and the seventh gear train G7 are provided. By constituting with one gear 41, 42, 43, respectively, the axial length of the automatic transmission can be shortened, and the mountability to the FF (front wheel drive) type vehicle can be improved.

  A reverse driven gear 44 that meshes with the reverse gear GR is fixed to the first input shaft 34.

  The first input shaft 34 is provided with a first meshing mechanism 61 and a third meshing mechanism 63 configured by a synchromesh mechanism. The first meshing mechanism 61 includes a third speed side connected state in which the third speed drive gear 73 and the first input shaft 34 are connected, and a seventh speed side connected state in which the seventh speed drive gear 77 and the first input shaft 34 are connected. The high-speed drive gear 73, the seventh-speed drive gear 77, and the first input shaft 34 are configured to be freely selectable to be switched to any one of the neutral states. The third meshing mechanism 63 is configured to be switchably selectable between a five-speed side connected state in which the fifth-speed drive gear 75 and the first input shaft 34 are connected, and a neutral state in which this connection is broken.

  The second input shaft 35 is provided with a second meshing mechanism 62 and a fourth meshing mechanism 64 configured by a synchromesh mechanism. The second meshing mechanism 62 includes a second speed side connected state in which the second speed drive gear 72 and the second input shaft 35 are connected, and a sixth speed side connected state in which the sixth speed drive gear 76 and the second input shaft 35 are connected. The high-speed drive gear 72 and the sixth-speed drive gear 76 and the second input shaft 35 are configured to be selectable to be switched to any one of the neutral states in which the connection between the second input shaft 35 is cut off. The fourth meshing mechanism 64 is configured to be switchably selectable between a four-speed side connected state in which the four-speed drive gear 74 and the second input shaft 35 are connected, and a neutral state in which this connection is broken.

  The reverse shaft 36 includes a synchromesh mechanism, and has a reverse meshing mechanism 65 that can be switched between a connected state in which the reverse gear GR and the reverse shaft 36 are connected and a neutral state in which the connection is cut off. Is provided.

  Further, the input shaft 53 of the auxiliary machine 5 is arranged in parallel to the reverse shaft 36. The reverse shaft 36 and the input shaft 53 of the auxiliary machine 5 are coupled via, for example, a belt mechanism 55. In the belt mechanism 55, a reverse sub gear 70 fixed on the first input shaft 34 and a gear 54 fixed on the input shaft 53 are connected via a belt so as to rotate integrally with the reverse gear GR. Configured. The gear 54 and the input shaft 53 of the accessory 5 are connected coaxially via an accessory clutch 56.

  The auxiliary device clutch 56 is a clutch that operates so as to connect or disconnect between the gear 54 and the input shaft 53 of the auxiliary device 5 under the control of the control device 21. In this case, when the auxiliary machine clutch 56 is operated in the connected state, the gear 54 and the input shaft 53 of the auxiliary machine 5 are coupled to rotate integrally. Further, when the auxiliary device clutch 56 is operated in the disconnected state, the coupling between the gear 54 and the input shaft 53 of the auxiliary device 5 by the auxiliary device clutch 56 is released. In this state, power transmission from the first input shaft 34 to the input shaft 53 of the auxiliary machine 5 is interrupted. As described above, the power is transmitted to the input shaft 53 of the auxiliary machine 5 and rotated to transmit the power to the auxiliary machine 5. At this time, the auxiliary machine 5 is an oil pump or a compressor of an air conditioner, and is driven by the transmitted driving force (mechanical power) of the engine 10 or the electric motor 11.

  Here, the first clutch 51 corresponds to the “engagement device” in the first aspect of the present invention, and corresponds to the “first clutch” in the second aspect and the third aspect. The second clutch 52 corresponds to the “engagement device” in the first aspect of the present invention, and corresponds to the “second clutch” in the second aspect and the third aspect. The odd-numbered gear trains G3, G5, and G7 correspond to the “first transmission mechanism” in the second and third aspects of the present invention, and the even-numbered gear trains G2, G4, and G6 correspond to the second and third aspects of the present invention. This corresponds to the “second transmission mechanism” in the third aspect. The drive gear of the even-numbered gear train is pivotally supported or fixed to the input shaft to which the motor 11 is connected, and the drive gear of the odd-numbered gear train is pivotally supported or fixed to the input shaft to which the motor 11 is not connected. May be. The driven shaft 38 corresponds to the “vehicle propulsion shaft” in the present invention. In the hybrid vehicle 1 of the present embodiment, the driven shaft 38 as the vehicle propulsion shaft is configured by one shaft, but the present invention is not limited to this, and the vehicle propulsion shaft may be configured by two shafts.

  Next, the operation of the automatic transmission 31 configured as described above will be described.

  In the automatic transmission 31, the engine 10 can be started using the driving force of the electric motor 11 by engaging the first clutch 51.

  When the first speed is established using the driving force of the engine 10, the ring gear 17 of the planetary gear mechanism 15 is fixed by the lock mechanism 60, and the first clutch 51 is engaged to be engaged. Here, traveling using only the driving force of the engine 10 is referred to as ENG traveling.

  The driving force of the engine 10 is input to the sun gear 16 of the planetary gear mechanism 15 via the engine output shaft 32, the first clutch 51, and the first input shaft 34, and the rotational speed of the engine 10 input to the engine output shaft 32. Is decelerated to 1 / (g + 1) and transmitted to the third-speed drive gear 73 via the carrier 18.

  The driving force transmitted to the third speed drive gear 73 is the gear ratio (the number of teeth of the drive gear / the number of teeth of the driven gear) of the third speed gear train G3 composed of the third speed drive gear 73 and the first driven gear 41. i is shifted to 1 / {i (g + 1)} and output from the output gear 33 via the first driven gear 41 and the driven shaft 38, and the first gear is established.

  In this way, in the automatic transmission 31, the first gear can be established by the planetary gear mechanism 15 and the third gear train, so that a meshing mechanism dedicated to the first gear is not required, thereby shortening the axial length of the automatic transmission. Can be achieved.

  In the first gear, the control device 21 generates power by applying a brake with the electric motor 11 in accordance with the SOC (State Of Charge) of the power storage device 2 and the vehicle is in a decelerating state. Perform deceleration regenerative operation. Further, according to the SOC of the power storage device 2, the electric motor 11 is driven and HEV (Hybrid Electric Vehicle) traveling that assists the driving force of the engine 10, or EV (Electric Vehicle) traveling that travels only by the driving force of the electric motor 11. It can be performed.

  Further, when the vehicle is traveling in EV and the vehicle is allowed to decelerate and the vehicle speed is equal to or higher than a certain speed, the driving force of the electric motor 11 is used by gradually engaging the first clutch 51. Instead, the engine 10 can be started using the kinetic energy of the vehicle.

  In addition, when the control device 21 predicts from the various electric signals such as the vehicle speed and the amount of operation of the accelerator pedal that the upshift to the second gear is performed during traveling at the first gear, the second meshing mechanism 62 is set to 2 A second-speed side connected state in which the high-speed driving gear 72 and the second input shaft 35 are connected or a pre-shift state approaching this state is set.

  When the second speed is established using the driving force of the engine 10, the second meshing mechanism 62 is brought into a second speed side coupling state in which the second speed driving gear 72 and the second input shaft 35 are coupled, and the second clutch 52 is fastened to the engaged state. In this case, the driving force of the engine 10 is output from the output gear 33 via the second clutch 52, the idle gear train GI, the second input shaft 35, the second speed gear train G2, and the driven shaft 38.

  When the control device 21 predicts an upshift at the second speed stage, the first meshing mechanism 61 is connected to the third speed drive state where the third speed drive gear 73 and the first input shaft 34 are connected. The pre-shift state is approaching the state.

  Conversely, when the control device 21 predicts a downshift, the first meshing mechanism 61 is in a neutral state in which the connection between the third speed drive gear 73 and the fifth speed drive gear 75 and the first input shaft 34 is disconnected. To do.

  As a result, an upshift or a downshift can be performed simply by setting the first clutch 51 to the engaged state and the second clutch 52 to the disengaged state, and smoothly switching the shift speed without interrupting the driving force. be able to.

  Even at the second speed, when the vehicle is in a decelerating state, control device 21 performs a deceleration regenerative operation in accordance with the SOC of power storage device 2. When performing the deceleration regenerative operation in the second speed stage, it differs depending on whether the first meshing mechanism 61 is in the third speed side connected state or in the neutral state.

  When the first meshing mechanism 61 is in the third-speed-side connected state, the third-speed drive gear 73 that is rotated by the first driven gear 41 that is rotated by the second-speed drive gear 72 is connected via the first input shaft 34 to the electric motor 11. In order to rotate the rotor 13, the rotation of the rotor 13 is suppressed and braking is applied to generate electricity and perform regeneration.

  When the first meshing mechanism 61 is in the neutral state, the rotational speed of the ring gear 17 is set to “0” by setting the lock mechanism 60 in a fixed state, together with the third speed drive gear 73 meshing with the first driven gear 41. Regeneration is performed by applying a brake by causing the electric motor 11 connected to the sun gear 16 to generate the rotational speed of the rotating carrier 18.

  When HEV traveling is performed at the second speed, for example, the first meshing mechanism 61 is set to the third speed-side connection state where the third speed drive gear 73 and the first input shaft 34 are connected, and the lock mechanism 60 is opened. Thus, the planetary gear mechanism 15 can be made in a state in which the respective elements cannot be rotated relative to each other, and the driving force of the electric motor 11 is transmitted to the output gear 33 via the third-speed gear train G3. Alternatively, the first meshing mechanism 61 is set to the neutral state, the lock mechanism 60 is set to the fixed state, the rotation speed of the ring gear 17 is set to “0”, and the driving force of the motor 11 is transmitted to the first driven gear 41 through the first speed path. This makes it possible to perform HEV traveling at the second gear. In this case, in addition to the driving force of the engine 10 during ENG traveling at the second speed, the driving force of the electric motor 11 is transmitted to the output gear 33 via the first input shaft 34, the third gear train G3, and the driven shaft 38. Is done.

  When the third speed is established using the driving force of the engine 10, the first meshing mechanism 61 is set to the third speed side connected state in which the third speed driving gear 73 and the first input shaft 34 are connected, and the first clutch 51 is fastened to the engaged state. In this case, the driving force of the engine 10 is transmitted to the output gear 33 via the engine output shaft 32, the first clutch 51, the first input shaft 34, the first meshing mechanism 61, and the third speed gear train G3. It is output at the rotation number i.

  At the third speed, the first meshing mechanism 61 is in the third speed side connected state in which the third speed drive gear 73 and the first input shaft 34 are connected. Therefore, the sun gear 16 and the carrier 18 of the planetary gear mechanism 15 Are the same rotation.

  Accordingly, each element of the planetary gear mechanism 15 becomes in a state in which relative rotation is impossible, and if the sun gear 16 is braked by the electric motor 11, deceleration regeneration is performed, and if the driving force is transmitted to the sun gear 16 by the electric motor 11, HEV traveling is performed. Can do. In this case, in addition to the driving force of the engine 10 during ENG traveling at the third speed, the driving force of the electric motor 11 is transmitted to the output gear 33 via the first input shaft 34, the third gear train G3, and the driven shaft 38. Is done.

  Further, the first clutch 51 is released (at this time, the second clutch 52 is already in an open state. If the second clutch 52 is not in an open state, it is in an open state), and only the driving force of the electric motor 11 is used. EV traveling is also possible.

  In the third speed, the control device 21 causes the second meshing mechanism 62 to be connected to the second speed drive gear 72 and the second input when a downshift is predicted based on various electric signals such as the vehicle speed and the accelerator pedal operation amount. When the second-speed side connected state connecting the shaft 35 or the pre-shift state approaching this state is set and an upshift is predicted, the fourth meshing mechanism 64 is connected to the fourth-speed drive gear 74 and the second input shaft 35. It is set as the 4th speed side connection state to connect, or the pre-shift state which approaches this state.

  As a result, it is possible to change the gear position by simply engaging the second clutch 52 and bringing the clutch into the engaged state, and releasing the first clutch 51 and making the gear shift smoothly without interruption of the driving force. Can be done.

  When the fourth speed is established using the driving force of the engine 10, the fourth meshing mechanism 64 is set to the fourth speed side coupling state in which the fourth speed driving gear 74 and the second input shaft 35 are coupled, and the second clutch 52 is fastened to an engaged state. In this case, the driving force of the engine 10 is output from the output gear 33 via the second clutch 52, the idle gear train GI, the second input shaft 35, the fourth speed gear train G4, and the driven shaft 38.

  When the control device 21 predicts a downshift from various electric signals during traveling at the fourth speed stage, the first meshing mechanism 61 is connected to the third speed drive gear 73 and the first input shaft 34 to the third speed. A side-connected state or a pre-shift state approaching this state.

  Conversely, when the control device 21 predicts an upshift from various electrical signals, the third meshing mechanism 63 is connected to the fifth speed drive gear 75 and the first input shaft 34, or the fifth speed connected state, The pre-shift state is approached to this state. As a result, the first clutch 51 can be engaged and engaged, and the second clutch 52 can be disengaged simply by releasing it. Thus, downshifting or upshifting can be performed, and the driving force is not interrupted. It can be done smoothly.

  When performing deceleration regeneration or HEV traveling during traveling at the fourth speed, when the control device 21 predicts a downshift, the first meshing mechanism 61 is connected to the third speed driving gear 73 and the first input shaft 34. It is possible to perform the deceleration regeneration if the brake is applied by the electric motor 11 and the driving force is transmitted, and HEV traveling can be performed if the connected state is the third speed side connected state. In this case, in addition to the driving force of the engine 10 during ENG traveling at the fourth speed, the driving force of the electric motor 11 is transmitted to the output gear 33 via the first input shaft 34, the third gear train G3, and the driven shaft 38. Is done.

  When the control device 21 predicts an upshift, the third meshing mechanism 63 is brought into a fifth speed side connected state in which the fifth speed drive gear 75 and the first input shaft 34 are connected, and if the electric motor 11 applies a brake, deceleration regeneration is performed. If the driving force is transmitted from the electric motor 11, HEV traveling can be performed. In this case, in addition to the driving force of the engine 10 during ENG traveling at the fourth speed, the driving force of the electric motor 11 is transmitted to the output gear 33 via the first input shaft 34, the fifth speed gear train G5, and the driven shaft 38. Is done.

  When the fifth speed stage is established using the driving force of the engine 10, the third meshing mechanism 63 is set in the fifth speed side connected state in which the fifth speed drive gear 75 and the first input shaft 34 are connected. At the fifth speed, since the first clutch 51 is engaged and the engine 10 and the electric motor 11 are directly connected to each other, HEV traveling can be performed by outputting driving force from the electric motor 11. If the electric motor 11 is braked to generate electric power, deceleration regeneration can be performed.

  Note that when EV traveling is performed at the fifth speed, the first clutch 51 may be in an open state (at this time, the second clutch 52 is already in an open state. If the second clutch 52 is not in an open state) Open). Further, the engine 10 can be started by gradually engaging the first clutch 51 during EV traveling at the fifth speed.

  When a downshift from various electrical signals to the fourth speed is predicted during traveling at the fifth speed, the control device 21 causes the fourth meshing mechanism 64 to connect the fourth speed drive gear 74 and the second input shaft 35. When the connected fourth speed side connected state or the pre-shift state approaching this state is set and an upshift is predicted, the second meshing mechanism 62 connects the sixth speed drive gear 76 and the second input shaft 35 6. Let it be a fast-side connected state or a pre-shift state approaching this state.

  As a result, it is possible to change the gear position by simply engaging the second clutch 52 and bringing the clutch into the engaged state, and releasing the first clutch 51 and making the gear shift smoothly without interruption of the driving force. Can be done.

  When the sixth speed is established using the driving force of the engine 10, the second meshing mechanism 62 is brought into a sixth speed connected state in which the sixth speed driving gear 76 and the second input shaft 35 are connected, and the second clutch 52 is fastened to an engaged state. In this case, the driving force of the engine 10 is output from the output gear 33 via the second clutch 52, the idle gear train GI, the second input shaft 35, the sixth speed gear train G6, and the driven shaft 38.

  If the control device 21 predicts a downshift from various electrical signals during traveling at the sixth speed, the third meshing mechanism 63 is connected to the fifth speed drive gear 75 and the first input shaft 34. A side-connected state or a pre-shift state approaching this state.

  Conversely, when the control device 21 predicts an upshift from various electrical signals, the first meshing mechanism 61 is connected to the seventh speed drive gear 77 and the first input shaft 34, or is connected to the seventh speed side. The pre-shift state is approached to this state. As a result, the first clutch 51 can be engaged and engaged, and the second clutch 52 can be disengaged simply by releasing it. Thus, downshifting or upshifting can be performed, and the driving force is not interrupted. It can be done smoothly.

  When performing deceleration regeneration or HEV traveling during traveling at the sixth speed, when the control device 21 predicts a downshift, the third meshing mechanism 63 is connected to the fifth speed driving gear 75 and the first input shaft 34. If the connected state is the fifth-speed side and the brake is applied by the electric motor 11, deceleration regeneration can be performed, and HEV traveling can be performed if the driving force is transmitted. In this case, in addition to the driving force of the engine 10 during ENG traveling at the sixth speed, the driving force of the electric motor 11 is transmitted to the output gear 33 via the first input shaft 34, the fifth gear train G3, and the driven shaft 38. Is done.

  When the control device 21 predicts an upshift, the first meshing mechanism 61 is brought into a seventh-speed connected state in which the seventh-speed drive gear 77 and the first input shaft 34 are connected, and if the brake is applied by the electric motor 11, deceleration regeneration is performed. If the driving force is transmitted from the electric motor 11, HEV traveling can be performed. In this case, in addition to the driving force of the engine 10 during ENG traveling at the sixth speed, the driving force of the electric motor 11 is transmitted to the output gear 33 via the first input shaft 34, the seventh speed gear train G7, and the driven shaft 38. Is done.

  When the seventh speed is established using the driving force of the engine 10, the first meshing mechanism 61 is in a seventh speed side connected state in which the seventh speed drive gear 77 and the first input shaft 34 are connected. At the seventh speed, since the first clutch 51 is engaged and the engine 10 and the electric motor 11 are directly connected, the HEV traveling can be performed if the driving force is output from the electric motor 11. If the electric motor 11 is braked to generate electric power, deceleration regeneration can be performed.

  When EV traveling is performed at the seventh speed, the first clutch 51 may be in an open state (at this time, the second clutch 52 is already in an open state. If the second clutch 52 is not in an open state) Open). Further, the engine 10 can also be started by gradually engaging the first clutch 51 during EV traveling at the seventh speed.

When the downshift from the various electrical signals to the sixth speed is predicted while traveling at the seventh speed, the control device 21 causes the second meshing mechanism 62 to move between the sixth speed drive gear 76 and the second input shaft 35. The connected 6th-speed side connected state or a pre-shifted state approaching this state.
As a result, the downshift to the sixth gear can be smoothly performed without interruption of the driving force.

  When the first reverse speed stage is established using the driving force of the engine 10, the lock mechanism 60 is set in a fixed state, the reverse meshing mechanism 65 is set in a connected state in which the reverse gear GR and the reverse shaft 36 are connected, The clutch 52 is engaged and brought into an engaged state. As a result, the driving force of the engine output shaft 32 moves backward via the second clutch 52, the idle gear train GI, the reverse gear GR, the reverse driven gear 44, the sun gear 16, the carrier 18, the third speed gear train G3, and the driven shaft 38. As the rotation in the direction, it is output from the output gear 33 and the first reverse speed is established.

  At this time, instead of setting the lock mechanism 60 in a fixed state, the third speed stage can be established if the first meshing mechanism 61 is set to the third speed side connected state, and if the first meshing mechanism 61 is set to the seventh speed side connected state. The seventh reverse speed can be established, and the fifth reverse speed can be established if the third meshing mechanism 63 establishes the fifth speed connected state.

  Next, a control process executed by the control device 21 will be described with reference to FIGS.

  FIG. 2 is a flowchart illustrating a control processing procedure executed by the control device 21. The control process of the control device 21 is called and executed every predetermined time (for example, 10 msec).

  First, in the first step ST1, it is determined whether or not the hybrid vehicle 1 is traveling in EV. If it is determined in step ST1 that the hybrid vehicle 1 is not in EV travel (if the determination result in step ST1 is NO), the process proceeds to step ST2.

  In step ST2, the power output from the power storage device 2 is changed so as to be controlled according to the normal output characteristics (hereinafter referred to as “normal output characteristics”) Mn shown in FIG. As shown in FIG. 3, the maximum power supplied from the power storage device 2 is in accordance with the SOC of the current power storage device 2. In FIG. 3, the horizontal axis is SOC (unit: [%], for example), and the vertical axis is output power of the power storage device 2 (unit: [kW], for example). In FIG. 3, the broken line is the normal output characteristic Mn, and the solid line is the SOC-output characteristic (hereinafter referred to as “restricted output characteristic”) Me used when limiting the power output from the power storage device 2. The normal output characteristic Mn is the rated output power of the power storage device 2. Here, the rated output voltage is the maximum output voltage at which the battery can be stably used continuously. That is, when the power supplied from the power storage device 2 is controlled according to the normal output characteristic Mn, the control device 21 does not limit the output of the power storage device 2.

  As shown in FIG. 3, the normal output characteristic Mn and the limited output characteristic Me have higher outputs as the SOC becomes higher. Further, the limited output characteristic Me is set to have a lower output for each SOC than the normal output characteristic Mn. Details of FIG. 3 will be described later.

  If it is determined in step ST1 that the hybrid vehicle 1 is running on EV (if the determination result in step ST1 is YES), the process proceeds to step ST3. In step ST3, it is determined whether or not the throttle opening is fully opened. As described above, the operation amount of the accelerator pedal detected by the accelerator opening sensor 22 is input to the control device 21 as an electrical signal. The control device 21 determines whether or not the throttle opening is fully opened according to the input operation amount of the accelerator pedal. For example, the control device 21 determines that the throttle opening is fully open when the operation amount of the accelerator pedal is depressed by the maximum amount. Note that it is not necessary to determine that the throttle opening is fully open when the operation amount of the accelerator pedal is the maximum amount, for example, that the throttle opening is fully open when the operation amount of the accelerator pedal is greater than or equal to a predetermined amount. You may judge.

  If it is determined in step ST3 that the throttle opening is fully open (if the determination result in step ST3 is YES), the process proceeds to step ST2. If it is determined in step ST3 that the throttle opening is not fully open (if the determination result in step ST3 is NO), the process proceeds to step ST4.

  In step ST4, it changes so that the electric power output from the electrical storage apparatus 2 may be controlled according to the limitation output characteristic Me shown by FIG. When the control device 21 controls the power output from the power storage device 2 according to the limited output characteristic Me, unlike the normal output characteristic Mn, the control device 21 sets a power smaller than the maximum power that can be output from the power storage device 2 as the maximum value. To do. Since the voltage output from the power storage device 2 has a value corresponding to the SOC, by controlling the motor 11 so that the current flowing through the motor 11 is reduced, as a result, the power output from the power storage device 2 is reduced. It is small.

  Next, in step ST5, when starting the engine 10, a gear train is selected so that the output of the electric motor 11 for starting the engine 10 is reduced. When the engine 10 is started by the output of the electric motor 11, the electric motor 11 cranks the engine 10, that is, rotates the crankshaft (not shown) of the engine 10. The output of the electric motor 11 required at this time increases as the rotation speed of the crankshaft of the engine 10 increases.

  Here, when the engine 10 is started by the output of the electric motor 11, the rotation speed of the crankshaft of the engine 10 is determined according to the clutch (first clutch 51 or second clutch 52) to be engaged. The number of revolutions. That is, the rotational speed of the rotating body is the rotational speed of the first input shaft 34 and the engine output shaft 32 when the first clutch 51 is engaged, and the second clutch 52 is engaged. Is the rotational speed of the idle drive gear 80 and the engine output shaft 32.

  Further, after the engine 10 is started, the engine 10 needs to rotate at a rotational speed equal to or higher than the rotational speed (so-called idling rotational speed) for maintaining the operation of the engine 10. That is, when the rotational speed of the engine output shaft 32 (or the first input shaft 34 or the idle gear train GI) rotates at a rotational speed less than the idling rotational speed, the rotational speed of the engine 10 is equal to or higher than the idling rotational speed. Therefore, even if the engine 10 is started, it stops immediately.

  Therefore, the control device 21 ensures that the rotational speed of the engine output shaft 32 (or the first input shaft 34 or the idle drive gear 80) is as small as possible while ensuring the rotational speed equal to or higher than the idling rotational speed. Select to be a gear train.

  Here, the rotational speed of the engine output shaft 32 (or the first input shaft 34 or the idle drive gear 80) changes according to the traveling speed of the hybrid vehicle 1. If the traveling speed is the same, the first input shaft 34 is at the seventh speed out of the odd-numbered speed stages (any one of the first speed stage, the third speed stage, the fifth speed stage, and the seventh speed stage) in the gear ratio order. When traveling, the rotational speed is the smallest, and the rotational speed increases in the order of 7th gear → 5th gear → 3rd gear → 1st gear. Similarly, if the traveling speed is the same, the idle drive gear 80 travels at the sixth speed among the odd-numbered gear positions (any one of the second speed, the fourth speed, and the sixth speed) in the gear ratio order. The number of revolutions becomes the smallest when the engine is running, and the number of revolutions increases in the order of 6th speed → 4th speed → 2nd speed.

  For this reason, the control device 21 determines whether or not the rotational speed of the idle drive gear 80 is equal to or higher than the idling rotational speed when the sixth speed side is in the connected state. Is a candidate. When the rotational speed of the idle drive gear 80 in the sixth speed side connected state is less than the idling rotational speed, the control device 21 determines that the rotational speed of the idle drive gear 80 in the fourth speed side connected state is idling. It is determined whether or not the speed is equal to or higher than the number of revolutions.

  When the rotational speed of the idle drive gear 80 in the 4-speed side connected state is less than the idling rotational speed, the control device 21 determines the rotational speed of the idle drive gear 80 in the 2-speed side connected state. It is determined whether or not it is equal to or higher than the rotational speed. If the rotational speed is equal to or higher than the idling rotational speed, the second gear train G2 is set as a candidate. When the rotational speed of the idle drive gear 80 in the second speed side connected state is less than the idling rotational speed, the control device 21 does not select any of the even-numbered gear trains G2, G4, and G6.

  The control device 21 determines whether or not the current rotational speed of the first input shaft 34 is equal to or higher than the idling rotational speed. If the rotational speed is equal to or higher than the idling rotational speed, the gear train that establishes the currently selected gear position is selected. And In this case, the gear stage established for EV traveling is one of the odd-numbered gear stages in the gear ratio order, that is, one of the first gear, the third gear, the fifth gear, and the seventh gear. It is. For this reason, the gear trains that can be candidates are the gear trains of the currently established shift stages among the odd-numbered gear trains G3, G5, and G7. Further, at the time of this determination, if the current rotation speed of the first input shaft 34 is less than the idling rotation speed, the control device 21 does not select any of the odd-numbered gear trains G3, G5, and G7.

  When the control device 21 selects one of the even-numbered gear trains G2, G4, and G6 and the odd-numbered gear trains G3, G5, and G7 as a candidate based on the above determination, the control device 21 sets the even-numbered gear trains G2, G4, and G6. Of these, the number of rotations of the idle drive gear 80 when the drive gear (72, 74 or 76) of the gear train selected as the candidate is connected to the second input shaft 35 and the odd number gear trains G3, G5, G7 When the drive gear (73, 75 or 77) of the gear train selected as a candidate is connected to the first input shaft 34, the engine 10 is selected as a candidate for the rotational speed of the first input shaft 34 and the smaller rotational speed. Select as the gear train when starting.

  When the control device 21 determines that none of the even-numbered gear trains G2, G4, G6 is a candidate and any one of the odd-numbered gear trains G3, G5, G7 is a candidate, The candidate gear train is selected as the gear train when starting the engine 10 among the number gear trains G3, G5, and G7.

  When the control device 21 determines that any one of the even-numbered gear trains G2, G4, and G6 is a candidate and if any of the odd-numbered gear trains G3, G5, and G7 is not a candidate, The candidate gear train is selected as the gear train when starting the engine 10 among the number gear trains G2, G4, and G6.

  If none of the even-numbered gear trains G2, G4, and G6 and the odd-numbered gear trains G3, G5, and G7 are candidates as determined by the above determination, the control device 21 shifts from the currently established gear position. The gear of the gear stage in which the rotational speed of the first input shaft 34 is equal to or higher than the idling rotational speed when the drive gear of the gear train of the odd-numbered gear stage with the large gear ratio rank is connected to the first input shaft 34. Select a column. For example, when the fifth speed is established at this time, either the third gear stage (G3) or the first gear stage (G3) is selected.

  By the process of step ST5 as described above, the output of the electric motor 11 for starting the engine 10 can be reduced by selecting the gear train when the control device 21 starts the engine 10.

  As described above, when the control device 21 starts the engine 10 in the process of step ST5, the rotational speed when the output of the electric motor 11 is transmitted and the crankshaft of the engine 10 rotates is the so-called idling rotational speed. The gear train having the smallest number of revolutions is selected from the above gear trains (the number of revolutions capable of maintaining the operation of the engine 10). Generally, when rotating a member whose rotation has stopped, it is necessary to generate a larger output from the electric motor as the number of rotations during the rotation is higher. For this reason, when the engine 10 is cranked by the output of the electric motor 11, the gear train having the smallest rotational speed is selected from among the gear trains having the idling rotational speed or higher, and the clutch (first clutch) corresponding to the gear train is selected. By starting the engine 10 with the 51 or the second clutch 52) engaged, the output required by the electric motor 11 can be lowered. Thereby, possibility that the output for driving | running | working will fall can be reduced.

  In step ST6, it is determined whether or not the engine 10 should be started. The control device 21 is the sum of the output of the electric motor 11 necessary for traveling of the hybrid vehicle 1, the output of the electric motor 11 necessary for operating the auxiliary machine 5, and the output of the electric motor 11 necessary for starting the engine 10. Output (hereinafter referred to as “request output”) Pr.

  Here, the control device 21 outputs the output of the electric motor 11 necessary for traveling of the hybrid vehicle 1, the required driving force to the vehicle detected by the accelerator opening sensor 22, the traveling speed of the hybrid vehicle 1, and the automatic transmission 31. Is acquired based on the information of the currently established shift speed. This acquisition may be calculated, or may be referred to a table or the like that is determined in advance through experiments or the like and stored in the memory 212.

  The control device 21 acquires the output of the electric motor 11 necessary for the operation of the auxiliary machine 5 based on the output required for the auxiliary machine 5. For example, if the auxiliary device 5 is an oil pump, the control device 21 obtains an output according to the amount of lubrication, and if the auxiliary device 5 is a compressor of the air conditioner, obtains an output according to the set temperature or the air volume of the air conditioner. This acquisition may be calculated, or may be referred to a table or the like that is determined in advance through experiments or the like and stored in the memory 212.

  The control device 21 outputs the output of the electric motor 11 necessary for starting the engine 10, the torque for rotating the crankshaft of the engine 10, and the number of rotations when rotating the crankshaft (the first input shaft 34 or The rotation speed is calculated based on the number of revolutions of the idle drive gear 80.

  The torque for rotating the crankshaft of the engine 10 is determined by the rotational speed of the crankshaft of the engine 10 and the resistance when the engine 10 is slid. The torque is determined in advance by experiments or the like, and stored in the memory 212 as a table that can be searched based on the number of rotations of the crankshaft of the engine 10 or the like. The rotation speed at this time is the rotation speed of the first input shaft 34 or the idle drive gear 80 when the drive gear of the gear train selected in step ST5 is connected to the first input shaft 34 or the second input shaft 35.

  The required output Pr obtained in this way is the output of the electric motor 11 necessary for sufficiently executing each request (travel of the hybrid vehicle 1, operation of the auxiliary machine 5, and start of the engine 10) to the hybrid vehicle 1. Means. That is, when the output of the electric motor 11 is less than the required output Pr, there is a possibility that the request for the three hybrid vehicles 1 described above cannot be sufficiently executed, such as a decrease in output necessary for travel (a decrease in travel speed). is there.

  Then, in the control device 21, the output Pm of the motor 11 (hereinafter referred to as “motor maximum output”) corresponding to the maximum output of the power storage device 2 when controlled by the limited output characteristic Me is equal to or less than the required output Pr. It is determined whether or not. With this determination, if “Pm ≦ Pr”, the required output Pr is equal to or greater than the current maximum motor output Pm, and therefore it is determined that the engine 10 should be started. Further, as a result of this determination, when “Pm> Pr”, it is determined that the engine 10 should not be started because the required output Pr can be covered by the current motor maximum output Pm. At this time, a decrease in the output voltage of the power storage device 2 can be determined (predicted) by searching from a table obtained in advance through experiments or the like based on the discharge of the battery 2 (decrease in SOC). The motor maximum output Pm is determined by integrating the maximum current that can be output according to the predicted decrease in the output voltage. Determining (predicting) the decrease in the output voltage using a table or the like based on the decrease in the SOC corresponds to “predicting the voltage decrease caused by the battery discharge” in the present invention.

  In the present embodiment, since the determination is performed every predetermined time set to a relatively short time (10 msec), when the required output Pr becomes “Pm = Pr”, that is, “Pm <Pr”. However, in order to give some margin, it may be determined whether or not the sum of the required output Pr and the predetermined value α is larger than the maximum motor output Pm (Pm). <Pr + α). The predetermined value α is changed from “Pm> Pr” in the previous determination to “Pm <Pr” in the current determination due to an increase in the output of the electric motor 11 necessary for traveling due to sudden depression of the accelerator pedal or the like. The value is determined in advance by an experiment or the like as an unacceptable value and stored in the memory 212.

  When it is determined in step ST6 that the engine 10 should be started (when the determination result in step ST6 is YES), the process proceeds to step ST7. In step ST7, the clutch according to the gear train selected in step ST5 is brought into an engaged state among the first clutch 51 and the second clutch 52. That is, the control device 21 brings the first clutch 51 into an engaged state when any one of the odd-numbered gear trains G3, G5, and G7 is selected.

  At this time, if the selected gear train is different from the gear train of the currently established gear stage, the control device 21 connects the drive gear of the selected gear train to the first input shaft 34. In addition, the first engagement mechanism 61, the third engagement mechanism 63, or the lock mechanism 60 is controlled, and the first clutch 51 is engaged.

  Further, when any one of the even-numbered gear trains G2, G4, and G6 is selected, the control device 21 is configured to connect the drive gear of the selected gear train to the second input shaft 35 so as to be connected to the second input shaft 35. While controlling the meshing mechanism 62 or the fourth meshing mechanism 64, the second clutch 52 is brought into an engaged state.

  As a result, the crankshaft of the engine 10 is rotated by the output of the electric motor 11. For this reason, the control device 21 increases the electric power supplied from the power storage device 2 to the electric motor 11 by the electric power for rotating the crankshaft of the engine 10. As a result, the output of the electric motor 11 increases by the amount corresponding to the start of the engine 10, and the engine 10 can be started without affecting the EV running.

  When the process of step ST2 or step ST7 ends, or when it is determined in step ST6 that the engine 10 should not be started (when the determination result of step ST6 is NO), the process of this flowchart is ended.

  As described above, in the present embodiment, the control device 21 controls the power output from the power storage device 2 according to the flowchart of FIG. The control device 21 controls the electric power output from the power storage device 2 according to the limited output characteristics Me during EV traveling or when the engine 10 is to be started, except when the throttle opening is not fully open, and otherwise. The electric power output from the power storage device 2 is controlled according to the normal output characteristic Mn.

  As shown in FIG. 3, the limited output characteristic Me is set to have a lower output for each SOC than the normal output characteristic Mn. In the present embodiment, as described above, the power storage device 2 is composed of a lithium ion battery. In general, it is known that the open voltage (OCV: potential difference between output terminals of a battery) decreases in the lithium ion battery when the SOC decreases.

  Further, such a power storage device 2 has a characteristic that when the load increases rapidly, the output voltage temporarily decreases until the increased load decreases. The decrease in the output voltage is significantly reduced as the output power is increased before the load applied to the power storage device 2 is rapidly increased. In other words, when the load suddenly increases, the output voltage decreases significantly as the load applied to the power storage device 2 increases, that is, as the power output from the power storage device 2 increases.

  In the present embodiment, when both the first clutch 51 and the second clutch 52 are in the released state and the EV is running, the rotation of the crankshaft of the engine 10 is started by the electric motor 11 by the process of step ST7 in FIG. Is done. At this time, since the output of the electric motor 11 increases, it is necessary to supply more electric power from the power storage device 2 to the electric motor 11. As described above, when the engine 10 is started, it is necessary to rotate the crankshaft, so that the load on the power storage device 2 increases rapidly.

  When a large amount of output is supplied from the power storage device 2, a further supply output is required to start the engine 10, and the output voltage of the power storage device 2 temporarily decreases.

  In general, an electric motor has a characteristic that an output decreases when an input voltage decreases. The electric motor 11 of this embodiment also has the same characteristics. Therefore, the control device 21 increases the output current even when the output voltage of the power storage device 2 decreases in order to keep the output of the electric motor 11 constant.

  However, the current that can be output from the power storage device 2 has a maximum value, and a current that exceeds this value cannot be supplied. For this reason, in order to keep the output of the electric motor 11 constant, when the current for compensating for the decrease in the output voltage of the electric storage device 2 exceeds the maximum current that can be supplied from the electric storage device 2, the output of the electric motor 11 Will fall.

  Thus, when the output of the electric motor 11 falls, there exists a possibility that the electric motor maximum output Pm may become less than the request | requirement output Pr according to SOC of the electrical storage apparatus 2 at the present. In this case, the output for EV traveling is lowered by rotating the crankshaft of the engine 10, and the EV traveling is affected, for example, the traveling speed is lowered.

  For this reason, during EV traveling or when the engine 10 should be started, the power output from the power storage device 2 is controlled according to the limited output characteristic Me that reduces the output compared to the normal output characteristic Mn. Leave a margin for the power that can be output. As a result, even when the load of the power storage device 2 suddenly increases due to the start of the engine 10, the output power is kept small before the load suddenly increases. The value of the output voltage of the power storage device 2 is reduced.

  Therefore, even if the output of the electric motor 11 is increased when the required output Pr is increased for starting the engine 10, sufficient electric power can be supplied from the power storage device 2, and the electric motor maximum output Pm is less than the required output Pr. The possibility of becoming can be reduced.

  FIG. 4 is a diagram showing temporal changes of parameters when the engine 10 is started during EV traveling. FIG. 4A shows the change over time of the voltage supplied to the power storage device 2. In FIG. 4B, the solid line is obtained from the electric motor 11 when the electric power output from the power storage device 2 is controlled according to the electric power output device 2, the electric motor maximum output power Pm <b> 1 being the electric motor maximum output, and the dashed line. The required output Pr and the broken line indicate the normal motor maximum output Pm2, which is the maximum motor output when the power output from the power storage device 2 is controlled according to the normal output characteristic Mn.

  Here, the required output Pr (the one-dot chain line in FIG. 4B) is an output obtained by summing up all the outputs of the electric motor 11 necessary for EV traveling, the operation of the auxiliary machine 5 and the start of the engine 10 as described above. It is. 4A and 4B, the horizontal axis represents time, and the vertical axis in FIG. 4A represents the output voltage of the power storage device 2 (unit: [V], for example). The vertical axis represents the output of the electric motor 11 (unit: [kW], for example).

  A time t1 in FIG. 4 indicates a time when the first clutch 51 or the second clutch 52 starts a transition from the disengaged state to the engaged state in order to start the engine 10. Also, time t2 in FIG. 4 indicates the time when the engine 10 has been started. After time t2, the engine 10 is unstable because the rotational speed immediately after starting cannot be kept constant. Therefore, until the rotational speed stabilizes, the engine 10 does not affect running. The first clutch 51 or the second clutch 52 that is in the combined state is opened. Although omitted in FIG. 4, after time t <b> 2, the control device 21 starts HEV running with the first clutch 51 or the second clutch 52 engaged after the engine 10 has stabilized. .

  As shown in FIG. 4, until time t <b> 1, the electric power of the power storage device 2 is consumed by EV traveling and the SOC decreases, so that the voltage supplied to the motor 11 also decreases, and consequently the maximum motor output Pm also decreases. doing. Since the start of the engine 10 is started at the time t1, the output voltage of the power storage device 2 rapidly decreases due to a sudden increase in the load of the power storage device 2. As a result, the motor maximum output Pm also rapidly decreases. At this time, when the electric power output from the power storage device 2 is controlled in accordance with the normal output characteristic Mn, the required output Pr (one-dot chain line in FIG. 4B) is the normal motor maximum output Pm2 (FIG. 4B). (Broken line) is exceeded. Thereby, in order to keep the output of the electric motor 11 constant, the output voltage of the power storage device 2 cannot be compensated for by the increase of the output current, and the output for traveling decreases and affects the EV traveling. .

  However, in the present embodiment, as shown in the flowchart of FIG. 2, during EV traveling, the power output from power storage device 2 is controlled according to the limited output characteristic Me by the process of step ST4. For this reason, even when the load of the power storage device 2 increases rapidly, the decrease in the output voltage of the power storage device 2 is suppressed as compared with the case where control is performed according to the normal output characteristics Mn. For this reason, in the present embodiment, the required output Pr (the one-dot chain line in FIG. 4B) does not exceed the maximum motor output Pm1 at the time of restriction (the solid line in FIG. 4B). Thereby, the engine 10 can be started without the output voltage of the power storage device 2 affecting the EV running.

  Here, when the determination result in step ST1 is YES, the power output from the power storage device 2 is controlled according to the limited output characteristic Me, except when it is determined that the throttle is fully open. When the throttle is fully open, the control device 21 demands a large driving force from the vehicle even during EV traveling, so that the output of the electric motor 11 decreases as in the limited output characteristic Me. That is, in order to attach importance to the driving force of the electric motor 11, the power output from the power storage device 2 is controlled according to the normal output characteristic Mn so as to be the rated output of the power storage device 2. However, the determination in step ST2 may not be performed, and even in this case, the effect that the engine 10 can be started without affecting the EV traveling is obtained.

  Further, the process of the flowchart shown in FIG. 2 is called and executed every predetermined time (for example, 10 msec) set short as described above. For this reason, when the determination result of step ST1 is YES, it is substantially the same as when EV traveling is actually started.

  As described above, when the determination result in step ST1 is YES, in step ST4, the electric power output from the power storage device 2 is controlled according to the limited output characteristic Me. This is equivalent to starting the control of the output of the battery according to the limited output characteristic when starting to travel only with the output of the output, and corresponds to the output limiting process in the third aspect of the present invention.

  When the process of step ST7 is executed, the power output from the power storage device 2 is already controlled according to the limited output characteristic Me by the process of step ST4. This is the first aspect of the present invention, “the operation of the internal combustion engine is stopped, the engagement between the electric motor and the internal combustion engine by the engagement device is released, and the vehicle is output by the output of the electric motor. When running, when the electric motor and the internal combustion engine are engaged by the engagement device and the internal combustion engine is cranked by the mechanical power from the electric motor, the output of the battery according to the limit output characteristics Is controlled, "and in the second aspect," the operation of the internal combustion engine is stopped, and the engagement between the first clutch and the second clutch is released. When the engagement with the internal combustion engine is released and the vehicle is running by the output of the electric motor, the engagement by the first clutch or the second clutch Wherein the electric motor and the internal combustion engine is engaged, when cranking the internal combustion engine by a mechanical power from the motor, the output of the battery is controlled in accordance with the limited output characteristic "particular corresponding.

  Further, the process of step ST5 corresponds to “selecting the shift stage so that the output of the electric motor is minimized when cranking the internal combustion engine” in the second aspect of the present invention.

  In addition, the determination result in step ST6 is YES and the processing in step ST7 is executed. In the present invention, “the control means predicts a voltage drop caused by the discharge of the battery and cranks the internal combustion engine. Corresponds to the starting process in the third aspect of the present invention.

  As described above, in the hybrid vehicle 1 of the present embodiment, the control device 21 stores the electric power according to the limited output characteristic Me, which is a characteristic that the output is lower than the normal output characteristic Mn, instead of the normal output characteristic Mn. The power output from the device 2 is controlled. As a result, the engine 10 can be started without affecting the EV running.

  Further, the configuration of the hybrid vehicle is not limited to that of the present embodiment. For example, the hybrid vehicle may be configured as shown in FIG. A hybrid vehicle 301 shown in FIG. 5 includes an engine 110 as an internal combustion engine, an electric motor 111, a transmission 312, a power storage device 402 as a battery, and a control device 421 as control means. The hybrid vehicle 301 uses an engine 110 and an electric motor 111 as drive sources.

  The power storage device 402 is electrically connected so as to supply electric power to the electric motor 111.

  The output shaft 322 of the engine 110 and the input shaft 342 of the transmission 312 are configured to be connectable / disengageable by a clutch 450 serving as an engagement device. The clutch 450 is a hydraulically operated dry friction clutch or a wet friction clutch. When the clutch 450 is connected, the driving force of the engine 110 is transmitted to the input shaft 342.

  The transmission 312 shifts the rotational speed based on the driving force transmitted to the input shaft 342 and the rotational speed based on the driving force of the electric motor 111 with a set speed ratio, and is driven via the output shaft 352 as a vehicle propulsion shaft. It is transmitted to a wheel (not shown). The transmission 312 may be a stepped transmission or a continuously variable transmission.

  The control device 421 is configured similarly to the control device 21 of the present embodiment. The operation of the engine 110, the electric motor 111, the transmission 312, the power storage device 402, and the like is controlled. In addition, the control device 421 executes a control process (FIG. 2) as in the present embodiment.

  The hybrid vehicle 301 can perform EV traveling when the clutch 450 is disengaged and the electric motor 111 outputs driving force. Further, when starting the engine 110 during EV travel, the engine 110 can be started by transmitting the driving force of the electric motor 111 to the engine 110 with the clutch 450 connected.

  Thus, even when the hybrid vehicle is configured, the control device is configured in the same manner as the control device 21 of the hybrid vehicle 1 of the present embodiment, so that the engine ENG can be started without affecting the EV traveling. The effect which this embodiment shows that it can do can be acquired.

  DESCRIPTION OF SYMBOLS 10 ... Engine (internal combustion engine), 11 ... Electric motor, 1 ... Hybrid vehicle, 2 ... Power storage device (battery), 21 ... Control device (control means), 31 ... Automatic transmission (transmission), 38 ... Driven shaft (vehicle) Propulsion shaft), 34 ... first input shaft, 35 ... second input shaft, 51 ... first clutch (engagement device, first clutch), 52 ... second clutch (engagement device, second clutch), Mn ... Normal output characteristic, Me ... Limited output characteristic, 301 ... Hybrid vehicle (another embodiment), 421 ... Control device (control means), 110 ... Engine (internal combustion engine), 111 ... Electric motor, 312 ... Transmission, 352 ... Vehicle Propulsion shaft, 450 ... clutch (engagement device), 402 ... power storage device (battery).

Claims (6)

A hybrid vehicle having an internal combustion engine and an electric motor as a prime mover, including a battery that functions as a power source for the electric motor, and capable of transmitting mechanical power output from the internal combustion engine and the electric motor to a vehicle propulsion shaft,
An engagement device for switching an engagement state between the internal combustion engine and the electric motor;
Control means for controlling the output from the battery according to a normal output characteristic of the battery or a limited output characteristic that suppresses the output compared to the normal output characteristic;
The control means is such that the operation of the internal combustion engine is stopped, the engagement between the electric motor and the internal combustion engine by the engagement device is released, and the vehicle is running by the output of the electric motor. In addition, when the electric motor and the internal combustion engine are engaged by the engagement device and the internal combustion engine is cranked by mechanical power from the electric motor, the output of the battery is controlled according to the limit output characteristics ,
The required output, which is a combination of at least the output of the electric motor necessary for traveling of the vehicle and the output necessary for cranking the internal combustion engine, becomes the maximum output of the battery controlled by the limited output characteristics. A hybrid vehicle , wherein the internal combustion engine is cranked and started when the corresponding maximum output of the electric motor is exceeded . A hybrid vehicle having an internal combustion engine and an electric motor as a prime mover, including a battery that functions as a power source for the electric motor, and capable of transmitting mechanical power output from the internal combustion engine and the electric motor to a vehicle propulsion shaft,
A first input shaft that receives mechanical power from the output shaft of the internal combustion engine and the output shaft of the electric motor by a first input shaft, and can change the speed by any one of a plurality of shift stages and transmit it to the vehicle propulsion shaft. A transmission mechanism;
A second speed change mechanism capable of receiving mechanical power from the output shaft of the internal combustion engine by a second input shaft, shifting the speed by any one of a plurality of shift stages, and transmitting the speed to the vehicle propulsion shaft;
A first clutch capable of engaging the output shaft of the internal combustion engine and the first input shaft;
A second clutch capable of engaging the output shaft of the internal combustion engine and the second input shaft;
Control means capable of controlling the selection of the gear position in the first transmission mechanism and the second transmission mechanism and the engagement state of the first clutch and the second clutch;
The control means controls the output from the battery in accordance with a normal output characteristic of the battery or a limited output characteristic that suppresses output compared to the normal output characteristic,
In the control means, the operation of the internal combustion engine is stopped, and the engagement between the electric motor and the internal combustion engine is released by releasing the engagement by the first clutch and the second clutch, When the vehicle is running by the output of the electric motor, the electric motor and the internal combustion engine are engaged by engagement by the first clutch or the second clutch, and the internal combustion engine is driven by mechanical power from the electric motor. When cranking the engine, control the output of the battery according to the limited output characteristics ,
The required output, which is a combination of at least the output of the electric motor necessary for traveling of the vehicle and the output necessary for cranking the internal combustion engine, becomes the maximum output of the battery controlled by the limited output characteristics. A hybrid vehicle , wherein the internal combustion engine is cranked and started when the corresponding maximum output of the electric motor is exceeded .   3. The hybrid vehicle according to claim 1, wherein the control unit starts controlling the output of the battery according to the limit output characteristic when the vehicle starts traveling only by the output of the electric motor. 4. A hybrid vehicle characterized by that.   The hybrid vehicle according to any one of claims 1 to 3, wherein the control means predicts a voltage drop caused by discharging of the battery and cranks and starts the internal combustion engine. vehicle.   3. The hybrid vehicle according to claim 2, wherein the control means selects the shift stage so that the output of the electric motor is minimized when cranking the internal combustion engine. A control method for a hybrid vehicle having an internal combustion engine and an electric motor as a prime mover, including a battery that functions as a power source of the electric motor, and capable of transmitting mechanical power output from the internal combustion engine and the electric motor to a vehicle propulsion shaft. ,
The hybrid vehicle
A first input shaft that receives mechanical power from the output shaft of the internal combustion engine and the output shaft of the electric motor by a first input shaft, and can change the speed by any one of a plurality of shift stages and transmit it to the vehicle propulsion shaft. A transmission mechanism;
A second speed change mechanism capable of receiving mechanical power from the output shaft of the internal combustion engine by a second input shaft, shifting the speed by any one of a plurality of shift stages, and transmitting the speed to the vehicle propulsion shaft;
A first clutch capable of engaging the output shaft of the internal combustion engine and the first input shaft;
A second clutch capable of engaging the output shaft of the internal combustion engine and the second input shaft;
The engagement between the first clutch and the second clutch is released to release the engagement between the electric motor and the internal combustion engine, and the normal output characteristics of the battery during traveling by the output of the electric motor. Output limiting process for controlling the output of the battery by changing to a limited output characteristic that suppresses output compared to the normal output characteristic
At least request output and the internal combustion engine of the motor required for the driving of the vehicle combined with the output required for cranking output is maximized become output of the battery being controlled by said limiting output characteristics A control method for a hybrid vehicle, comprising: starting processing for cranking and starting the internal combustion engine when the corresponding maximum output of the electric motor is exceeded.

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