JP6220159B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device including an engine and a motor generator.

  In recent years, hybrid vehicles including an engine and a motor generator have been developed. In such a hybrid vehicle, in order to charge a battery that supplies electric power to the motor generator, not only the motor generator generates electric power during running or braking, but also the motor generator generates electric power as necessary even when the vehicle is stopped. (See Patent Document 1).

JP 2003-235110 A

  When the motor generator is caused to generate power when the vehicle is stopped, the output clutch that transmits power to the drive wheels is released in order to maintain the stopped state. For this reason, at the time of power generation by the motor generator, the input side of the output clutch rotates in conjunction with the motor speed, while the output side of the output clutch stops with the drive wheels. Such a difference in the number of revolutions before and after the output clutch is a factor that reduces the responsiveness when the vehicle starts thereafter.

  That is, it is necessary to fasten the output clutch when the vehicle starts, but it is difficult to quickly fasten the output clutch when a large rotational speed difference occurs before and after the output clutch. Also, if the output clutch is to be quickly engaged without sufficiently synchronizing the rotational speeds before and after the output clutch, a large engagement shock is generated at the time of engagement.

  An object of the present invention is to fasten and smoothly fasten the output clutch.

A vehicle control device according to the present invention is a vehicle control device including an engine and a motor generator, and includes a lock-up clutch that is controlled in an engaged state and a released state, and is provided between the engine and the motor generator. A torque converter, a power transmission path that connects the torque converter and the motor generator, an output clutch that is provided between the power transmission path and the drive wheel, and is controlled in an engaged state and a released state, An output clutch is controlled to a released state, the motor generator is rotated by the engine, and the motor generator is controlled to a first regenerative state. Control to a large second regeneration state and reduce the rotational speed of the power transmission path to Possess a start control unit that controls the clutch engagement state, and the power generation control section, when controlling the motor generator to the first regenerative state, controls the lock-up clutch engagement state, the starting The control unit controls the motor generator to the second regenerative state after starting the release control of the lockup clutch when controlling the output clutch to the engaged state .

  According to the present invention, the motor generator is controlled to the second regenerative state where the regenerative torque is larger than that of the first regenerative state, and the output clutch is controlled to be in the engaged state by reducing the rotational speed of the power transmission path. Fast and smooth fastening is possible.

It is the schematic which shows the control apparatus for vehicles which is one embodiment of this invention. It is the schematic which shows the structure of the control apparatus for vehicles. It is a flowchart which shows an example of the execution procedure of vehicle start control. It is a timing chart which shows an example of the execution procedure of vehicle start control. (A)-(c) is the schematic which shows the operation state of the power unit until it performs creep driving | running | working via vehicle start control from a stop electric power generation mode.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a vehicle control apparatus 10 according to an embodiment of the present invention. As shown in FIG. 1, the vehicle control device 10 includes a power unit 13 including an engine 11 and a motor generator 12 as power sources. The power unit 13 is provided with a continuously variable transmission 14, and the continuously variable transmission 14 is provided with a primary pulley 15 and a secondary pulley 16. The engine 11 is connected to one side of the primary pulley 15 via an input clutch 17 and a torque converter 18. On the other hand, the motor generator 12 is connected to the other side of the primary pulley 15 via a rotor shaft 19. A drive wheel output shaft 21 is connected to the secondary pulley 16 via an output clutch 20. Drive wheels 23 are connected to the drive wheel output shaft 21 via a differential mechanism 22. Further, an integrated starter generator (ISG) 25 that also functions as a starter motor is connected to the crankshaft 24 of the engine 11 via a drive belt 26.

  The torque converter 18 includes a pump impeller 31 connected to the crankshaft 24 via a front cover 30, and a turbine runner 33 that faces the pump impeller 31 and is connected to the turbine shaft 32. Further, the torque converter 18 incorporates a lockup clutch 35 having a clutch plate 34. The clutch plate 34 is provided so as to be movable in the axial direction with respect to the turbine hub 36 connected to the turbine shaft 32. An apply chamber 37 is defined on the turbine runner 33 side of the clutch plate 34, and a release chamber 38 is defined on the front cover 30 side of the clutch plate 34. By supplying the operating oil to the apply chamber 37 and discharging the operating oil from the release chamber 38, the lockup clutch 35 can be controlled to be in the engaged state. On the other hand, by supplying the hydraulic oil to the release chamber 38 and discharging the hydraulic oil from the apply chamber 37, the lock-up clutch 35 can be controlled to the released state.

  The continuously variable transmission 14 has a primary shaft 42 connected to the rotor shaft 19 of the motor generator 12 and a secondary shaft 43 parallel to the primary shaft 42. A primary pulley 15 is provided on the primary shaft 42, and a primary chamber 44 is defined on the back side of the primary pulley 15. A secondary pulley 16 is provided on the secondary shaft 43, and a secondary chamber 45 is defined on the back side of the secondary pulley 16. Further, a drive chain 46 is wound around the primary pulley 15 and the secondary pulley 16. By adjusting the primary pressure supplied to the primary chamber 44 and the secondary pressure supplied to the secondary chamber 45, the pulley groove width can be changed and the winding diameter of the drive chain 46 can be changed. Thereby, continuously variable transmission from the primary shaft 42 to the secondary shaft 43 is possible.

  The torque converter 18 and the motor generator 12 are connected via a power transmission path 50 including the input clutch 17, the continuously variable transmission 14, the rotor shaft 19, and the like. The power transmission path 50 means a power transmission path 50 that connects the torque converter 18 and the motor generator 12, that is, a power transmission element group or a power transmission element. Further, an output clutch 20 is provided between the continuously variable transmission 14 and the drive wheels 23, that is, between the power transmission path 50 and the drive wheels 23, which is controlled in an engaged state and a released state. The output clutch 20 includes a clutch hub 51 connected to the secondary shaft 43 and a clutch drum 52 connected to the drive wheel output shaft 21. A friction plate 53 is attached to the clutch hub 51, and a friction plate 54 facing the friction plate 53 is attached to the clutch drum 52. A piston 55 is incorporated in the clutch drum 52, and a fastening oil chamber 56 is defined on the back side of the piston 55.

  By supplying hydraulic oil to the fastening oil chamber 56, the piston 55 can be moved in the fastening direction to press the friction plates 53 and 54 together, and the output clutch 20 can be switched to the fastening state. On the other hand, by discharging the hydraulic oil from the fastening oil chamber 56, the pressing of the friction plates 53 and 54 can be released, and the output clutch 20 can be switched to the released state. Further, by adjusting the clutch pressure supplied to the fastening oil chamber 56, the output clutch 20 can be controlled to the slip state. That is, by adjusting the clutch pressure supplied to the fastening oil chamber 56, the torque capacity of the output clutch 20 can be freely adjusted. The output clutch 20 functions as a so-called fuse clutch, and in the situation where excessive torque is transmitted from the drive wheels 23 toward the continuously variable transmission 14, the output clutch 20 is slipped to cause the continuously variable transmission 14 to slip. It is possible to protect.

  Next, supply of hydraulic oil to the continuously variable transmission 14, the torque converter 18, the input clutch 17, the output clutch 20, and the like will be described. As shown in FIG. 1, in order to supply hydraulic oil to the continuously variable transmission 14 or the like, the power unit 13 is electrically driven by a mechanical pump 60 that is rotated by a primary shaft 42 or the like and an electric motor 61 that is rotated by an electric motor 61. A pump 62 is provided. Further, the power unit 13 is provided with a valve unit 63 composed of a plurality of electromagnetic valves and oil passages in order to control the supply destination and pressure of the hydraulic oil.

  The mechanical pump 60 is connected to the primary shaft 42 via a chain mechanism 65 having a one-way clutch 64. The one-way clutch 64 transmits power to the mechanical pump 60 from the primary shaft 42 that rotates in the forward direction, while blocking power transmission in the opposite direction. Furthermore, the mechanical pump 60 is connected to a hollow shaft 68 fixed to the torque converter 18 via a chain mechanism 67 having a one-way clutch 66. The one-way clutch 66 transmits power to the mechanical pump 60 from the hollow shaft 68 that rotates in the forward direction, while blocking power transmission in the opposite direction. That is, when the primary shaft 42 rotates faster than the hollow shaft 68, the mechanical pump 60 is driven by the primary shaft 42 on the motor generator 12 side, while when the hollow shaft 68 rotates faster than the primary shaft 42. The mechanical pump 60 is driven by the hollow shaft 68 on the engine 11 side. The forward rotation direction of the primary shaft 42 is the rotation direction of the primary shaft 42 during forward travel. The forward rotation direction of the hollow shaft 68 is the rotation direction of the crankshaft 24 when the engine 11 is driven.

  Thus, the mechanical pump 60 has a structure driven by the primary shaft 42 on the motor generator 12 side and a structure driven by the hollow shaft 68 on the engine 11 side. As a result, in the parallel travel mode described later, the mechanical pump 60 can be driven by the engine 11, and hydraulic oil can be supplied from the mechanical pump 60 to the valve unit 63. Also, in the motor travel mode described later, the mechanical pump 60 can be driven by the primary shaft 42 when the vehicle travels with the primary shaft 42 rotating. In the motor travel mode, when the rotational speed of the primary shaft 42 falls below a predetermined threshold as the vehicle speed decreases, the electric pump 62 is driven to compensate for the decrease in the discharge pressure of the mechanical pump 60. In addition, when the vehicle is stopped in the motor travel mode, the driving state of the electric pump 62 is continued. However, when the vehicle speed increases and the rotation speed of the primary shaft 42 exceeds a predetermined threshold, Since the discharge pressure of the mechanical pump 60 is restored, the electric pump 62 is stopped.

  The vehicle control device 10 has a motor travel mode in which the input clutch 17 is released, the output clutch 20 is engaged, the engine 11 is stopped, and the motor generator 12 is driven as the travel mode. Further, the vehicle control device 10 has a parallel travel mode in which the input clutch 17 and the output clutch 20 are engaged and the engine 11 and the motor generator 12 are driven as the travel mode. Furthermore, the vehicle control device 10 includes a stop power generation mode in which the motor generator 12 is driven to generate power using the engine 11 when the vehicle is stopped. As the vehicle state in which the stop power generation mode is executed, for example, the vehicle is stopped under the state where the forward travel range (D range) is selected, and the charge state of the high voltage battery 69 connected to the motor generator 12 is A vehicle state in which the SOC falls below a predetermined lower limit value can be mentioned. When this stop power generation mode is executed, the input clutch 17 is controlled to be engaged, and the output clutch 20 is controlled to be released. As described above, since the output clutch 20 is released, the motor generator 12 can be driven to generate power by the engine 11 while maintaining the stopped state.

  Hereinafter, vehicle start control for fastening the output clutch 20 from the stop power generation mode will be described. FIG. 2 is a schematic diagram showing the configuration of the vehicle control device 10. 2, the same members as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 2, the vehicle control device 10 includes a control system 70 for the power unit 13. The vehicle control device 10 is provided with a control unit 71 that functions as a power generation control unit and a start control unit. The control unit 71 detects an engine rotation sensor 73 that detects the rotation speed of the engine 11 (hereinafter referred to as the engine rotation speed Ne) and a rotation speed of the motor generator 12 (hereinafter described as the motor rotation speed Nm). A motor rotation sensor 74 and an output shaft rotation sensor 75 for detecting the rotation speed of the drive wheel output shaft 21 (hereinafter referred to as output shaft rotation speed Nout) are connected. The control unit 71 includes a turbine rotation sensor 76 that detects the rotation speed of the turbine shaft 32, a primary rotation sensor 77 that detects the rotation speed of the primary shaft 42, and a rotation speed of the secondary shaft 43 (hereinafter referred to as secondary rotation speed Ns). ) Is connected to the secondary rotation sensor 78. The control unit 71 includes an inhibitor switch 79 for detecting the operation state of a select lever (not shown) by the driver, an accelerator sensor 80 for detecting an operation state of an accelerator pedal (not shown) by the driver, and an operation state of a brake pedal (not shown) by the driver. Is connected to a brake sensor 81. The control unit 71 is connected to a battery sensor 82 that detects charge / discharge current, voltage, and the like of the high voltage battery 69.

  The control unit 71 is connected to a throttle valve or an injector (not shown) that controls the engine 11, and the engine speed and engine torque are controlled by a control signal from the control unit 71. The control unit 71 is connected to an inverter 72 that controls the motor generator 12, and the motor rotation speed and motor torque are controlled by a control signal from the control unit 71. Furthermore, the control unit 71 is connected to a valve unit 63 that controls the lock-up clutch 35, the input clutch 17, the output clutch 20, and the like, and the clutches 17, 20, and 35 are engaged and released by a control signal from the control unit 71. Controlled by the state. The control unit 71 includes a CPU that calculates control signals and the like, a ROM that stores control programs, arithmetic expressions and map data, and a RAM that temporarily stores data.

  Then, the execution procedure of vehicle start control is demonstrated along a flowchart. FIG. 3 is a flowchart showing an example of an execution procedure of vehicle start control. As shown in FIG. 3, in step S <b> 1, a stop power generation mode in which the motor generator 12 is driven to generate power by the engine 11 is executed. In the stop power generation mode, the engine 11 is driven to rotate at a predetermined target torque by the idle-up control, and the motor generator 12 is controlled to a first regeneration state in which a predetermined regeneration torque is output, that is, a first power generation state. At this time, in order to transmit engine power to the motor generator 12, the input clutch 17 and the lock-up clutch 35 are controlled to be engaged. Further, the output clutch 20 is controlled to be in a disengaged state in order to keep the drive wheels 23 in a stopped state. The idle-up control of the engine 11 is a control for increasing the engine speed Ne from the idling state toward a predetermined target speed. The regenerative torque is a motor torque that acts in the opposite direction to the power running torque, that is, a motor torque that acts in a direction that reduces the rotational speed of the motor generator 12.

  In step S2, it is determined whether or not a stop power generation mode end condition is satisfied. An example of the stop condition in the stop / start mode is a case where a brake pedal depression operation is released. If it is determined in step S2 that the depression of the brake pedal has been released, that is, if it is determined that the stop power generation mode end condition has been established, the process proceeds to step S3, and the release control of the lockup clutch 35 is started. The In the subsequent step S4, the motor generator 12 is controlled to the second regeneration state, that is, the second power generation state in which the regeneration torque is larger than that in the first regeneration state. In this way, the release control of the lockup clutch 35 is started and the regenerative torque of the motor generator 12 is increased, so that the power transmission path 50 is braked by the motor generator 12 while the slip amount of the torque converter 18 is increased. Is possible. That is, the motor generator 12 is regeneratively braked, and the rotational speed of the primary shaft 42 and the secondary shaft 43 constituting the power transmission path 50 is quickly decreased by exceeding the decreasing speed of the engine rotational speed Ne and decreasing the motor rotational speed Nm. I am letting.

  In step S5, a rotational speed difference ΔC1 before and after the lockup clutch 35 is calculated, and in step S6, it is determined whether the rotational speed difference ΔC1 exceeds a predetermined threshold value α. If it is determined in step S6 that the rotational speed difference ΔC1 is equal to or smaller than the threshold value α, the process returns to step S3, and the release control of the lockup clutch 35 is continued. On the other hand, if it is determined in step S6 that the rotational speed difference ΔC1 exceeds the threshold value α, that is, if it is determined that the lock-up clutch 35 is controlled to the released state, the process proceeds to step S7 and the output clutch 20 is engaged. Control begins.

  When the engagement control of the output clutch 20 is started in step S7, the rotational speed difference ΔC2 before and after the output clutch 20 is calculated in step S8, and in step S9, the rotational speed difference ΔC2 becomes equal to or less than a predetermined threshold value β. It is determined whether or not. In step S9, when it is determined that the rotation speed difference ΔC2 exceeds the threshold value β, the process returns to step S7, and the engagement control of the output clutch 20 is continued. On the other hand, if it is determined in step S9 that the rotational speed difference ΔC2 is equal to or less than the threshold value β, that is, if it is determined that the output clutch 20 is controlled to the engaged state, the process proceeds to step S10, where Traveling in the travel mode is started.

  Thus, in the vehicle start control from the stop power generation mode, the lockup clutch 35 is released and the regenerative torque of the motor generator 12 is increased, so that the rotational speeds before and after the output clutch can be quickly synchronized. It becomes possible. That is, by regeneratively braking the motor generator 12 while slipping the torque converter 18, it is possible to reduce the motor rotational speed Nm beyond the decreasing speed of the engine rotational speed Ne. Thereby, the rotational speed of the secondary shaft 43 on the upstream side of the output clutch 20 can be quickly reduced, and the output clutch 20 can be quickly engaged from the stop power generation mode. In addition, since the rotation speeds before and after the output clutch can be quickly synchronized, the engagement shock of the output clutch 20 can be suppressed.

  Subsequently, the execution procedure of the vehicle start control will be described with reference to a timing chart. FIG. 4 is a timing chart showing an example of an execution procedure of vehicle start control. FIGS. 5A to 5C are schematic views showing the operation state of the power unit 13 from the stop power generation mode to creep running through vehicle start control. In addition, the thick line arrow described in FIGS. 5A to 5C indicates the transmission path of the engine torque and the motor torque. As described above, the vehicle state when the vehicle start control is started is a state in which the stop power generation mode is executed. That is, as shown in FIG. 5 (a), the engine 11 is in a state where the engine speed Ne is increased by the idle-up control, and the motor generator 12 is in a state controlled to the first regeneration state. Further, as shown in FIG. 5 (a), the input clutch 17 and the lockup clutch 35 are engaged, and the output clutch 20 is released.

  As shown in FIG. 4, in the stop power generation mode, the motor generator 12 is controlled to the first regeneration state in which the first regeneration torque Tm1 is output. When the stop power generation mode end condition is satisfied by releasing the brake pedal or the like, release control of the lockup clutch 35 is started (reference numeral X1). Then, when the torque capacity of the lockup clutch 35 decreases, the regenerative torque increase control in the motor generator 12 is started (reference X2), and the motor generator 12 is controlled toward the second regenerative state in which the second regenerative torque Tm2 is output. Is done. That is, the target motor rotation speed TNm of the motor generator 12 is reduced, and the regenerative torque of the motor generator 12 is increased so that the motor rotation speed Nm converges to the decreasing target motor rotation speed TNm.

  Then, when the lock-up clutch 35 is controlled to the released state (reference X3), the engagement control of the output clutch 20 is started (reference X4). When the engagement control of the output clutch 20 is started, the torque capacity of the output clutch 20 is gradually increased based on the rotational speed difference before and after the output clutch, that is, the rotational speed difference between the secondary rotational speed Ns and the output shaft rotational speed Nout. At the same time, the regenerative torque of the motor generator 12 is gradually reduced. When the secondary rotational speed Ns converges with respect to the output shaft rotational speed Nout (symbol X5), the torque capacity of the output clutch 20 is rapidly increased and the output clutch 20 is engaged. As a result, the vehicle can be started in the parallel traveling mode or the motor traveling mode.

  As described above, by starting the release control of the lock-up clutch 35 and then increasing the regenerative torque of the motor generator 12, as shown in FIG. The generator 12 is regeneratively braked. Accordingly, the rotational speed of the power transmission path 50 can be quickly reduced without increasing the torque capacity of the output clutch 20, and the rotational speed before and after the output clutch can be quickly synchronized. Therefore, the output clutch 20 can be quickly and smoothly engaged, and the vehicle can be quickly started from the stop power generation mode as shown in FIG. That is, as shown in FIG. 4, by increasing the regenerative torque of the motor generator 12, the motor rotation speed Nm can be decreased beyond the decrease speed of the engine rotation speed Ne, and the secondary rotation speed Ns can be output to the output shaft. It becomes possible to quickly decrease toward several Nout. Thereby, it becomes possible to fasten the output clutch 20 quickly and smoothly.

  On the other hand, when the regenerative torque of the motor generator 12 is maintained, the power transmission path 50 cannot be actively decelerated, so that it is difficult to quickly reduce the rotational speed difference before and after the output clutch. Therefore, as shown by the broken line Z in FIG. 4, when the output clutch 20 is to be fastened, it is necessary to rapidly increase the torque capacity of the output clutch 20, and as a result, the acceleration of the vehicle is greatly fluctuated. .

  Further, as indicated by reference numeral X6 in FIG. 4, the output torque of the motor generator 12 is adjusted even after the output clutch 20 is engaged. As a result, it is possible to freely adjust the acceleration when shifting from the stop power generation mode to the travel mode, and it is possible to improve vehicle quality. In the case shown in FIG. 4, the output torque of the motor generator 12 is controlled to 0 when executing the travel mode. However, the present invention is not limited to this, and the power generator torque is output from the motor generator 12. Also good. Further, in the case shown in FIG. 5 (c), the engine 11 is kept creeping while being maintained in an idling state. However, the present invention is not limited to this, and the engine torque and motor are controlled according to the driver's accelerator operation or the like. Torque (power running torque) may be increased. Further, as shown in FIG. 5B, when the motor generator 12 is regeneratively braked, it is desirable to control the engine 11 to an idling state in order to quickly reduce the rotational speed of the power transmission path 50.

  In the above description, the regenerative torque of the motor generator 12 is increased after the release control of the lockup clutch 35 is started. However, the present invention is not limited to this, and the lockup clutch 35 is maintained in the engaged state. The regenerative torque of the motor generator 12 may be increased. In order to quickly synchronize the rotational speeds before and after the output clutch, it is desirable to disconnect the engine 11 from the power transmission path 50 by releasing the lockup clutch 35. However, even when the lock-up clutch 35 is maintained in the engaged state, the rotational speed of the secondary shaft 43 and the like constituting the power transmission path 50 can be quickly reduced by increasing the regenerative torque of the motor generator 12. It becomes possible.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. In the above description, the power generation mode is executed when the vehicle is stopped. However, the present invention is not limited to this. For example, the power generation mode may be executed in an extremely low vehicle speed region immediately before the vehicle stops. Even when the vehicle start control is executed from such a power generation mode, the present invention can be effectively applied. In the above description, a hydraulic clutch that is hydraulically controlled is used as the output clutch 20, but the present invention is not limited to this, and an electromagnetic clutch that is controlled using electromagnetic force may be used as the output clutch 20. .

  In the illustrated case, the speed change mechanism is incorporated in the power unit 13, but the present invention is not limited to this, and the speed change mechanism may be reduced from the power unit 13. Further, in the illustrated case, the chain drive type continuously variable transmission 14 is used as the speed change mechanism, but the present invention is not limited to this, and even a belt drive type or traction drive type continuously variable transmission may be used. It may be a planetary gear type or parallel shaft type automatic transmission.

DESCRIPTION OF SYMBOLS 10 Vehicle control apparatus 11 Engine 12 Motor generator 20 Output clutch 23 Drive wheel 35 Lockup clutch 50 Power transmission path 71 Control unit (power generation control part, start control part)

Claims (1)

A vehicle control device including an engine and a motor generator,
A torque converter provided between the engine and the motor generator , comprising a lock-up clutch that is controlled in an engaged state and a released state ;
A power transmission path connecting the torque converter and the motor generator;
An output clutch which is provided between the power transmission path and the drive wheel and is controlled in an engaged state and a released state;
A power generation control unit that controls the output clutch to a disengaged state, rotationally drives the motor generator by the engine, and controls the motor generator to a first regeneration state;
A start control unit that controls the motor generator to a second regenerative state having a larger regenerative torque than the first regenerative state, and controls the output clutch to be in an engaged state by reducing a rotational speed of the power transmission path;
I have a,
The power generation control unit controls the lock-up clutch to an engaged state when controlling the motor generator to the first regeneration state,
The start control unit controls the motor generator to the second regeneration state after starting the release control of the lockup clutch when the output clutch is controlled to be engaged.
Vehicle control device.

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