JP2011201449A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration in the durability of an electric storage device which is loaded on a vehicle.SOLUTION: A power transmission device (1) includes: a motorized differential part (21) which has a differential mechanism (24) and in which a first rotating element of the differential mechanism is connected to a first motor (M1), and a second rotating element of the differential mechanism is connected to an internal combustion engine (10), and a third rotating element of the differential mechanism is connected to a second motor (M2); a stepped speed change part (22); an electric storage device (12); a voltage adjusting means (11) for transferring power among the first motor and the second motor and the electric storage device, and adjusting a voltage; and a control means (30) for controlling the voltage adjusting means to change the voltage when power transfer exceeds the restriction relating to the power transfer during shift due to the execution of the shift of the stepped speed change part when power transfer is restricted.

Description

  The present invention relates to a technical field of a power transmission device that is mounted on a vehicle such as an automobile and includes a continuously variable transmission unit and a stepped transmission unit.

  As this type of device, for example, the condition that the sum of the torques output from the motors MG1 and MG2 to the drive shaft is within the range from zero to the required torque Tr *, and the sum of the electric power input and output from the motors MG1 and MG2. Is within the range of the Win limit, which is the maximum charge power allowed for ensuring and protecting the battery durability, and the Wout limit, which is the maximum discharge power allowed for ensuring and protecting the battery durability, and The torque limit Tmlmin, Tmlmax is within a range that satisfies the condition where the torque of the motor MG2 is within the range from the allowable maximum change amount ΔT having a negative value to the value obtained by adding the allowable maximum change amount ΔT to the previous torque command Tm2 *. To set torque command Tm1 * for motor MG1, and drive required torque Tr * within the range of battery input / output limits Win and Wout An apparatus for setting a torque command Tm2 * of the motor MG2 to be output to a shaft has been proposed (see Patent Document 1).

  Alternatively, when the battery discharge power limit is temporarily relaxed according to the load discharge requirement, the discharge allowable power value is predicted according to the multiplication of the lower limit voltage and the maximum dischargeable current, and the discharge limit is temporarily set. An apparatus has been proposed in which the battery voltage is set in accordance with the maximum dischargeable power that does not decrease below the lower limit voltage even if the relaxation is performed (see Patent Document 2).

  Alternatively, in order to suppress the rotation of the first motor within the predetermined input / output allowable range of the power storage device during the shift of the automatic transmission unit, the sum of the output of the first motor and the output of the second motor is within a predetermined input / output allowable range of the power storage device. There has been proposed a device that generates a cancel torque and keeps the rotational speed of the first electric motor within a predetermined rotational speed range (see Patent Document 3).

  Alternatively, the first rotating element is connected to the first electric motor, the second rotating element is connected to the second electric motor via the transmission shaft, and the third rotating element is connected to the engine, and the rotation transmitted to the transmission shaft. An inertia compensation torque that compensates for fluctuations in rotational speed due to inertia in accordance with the speed change of the transmission, and a first according to the calculated inertia compensation torque. An apparatus for correcting a torque that is a target of an electric motor has been proposed (see Patent Document 4).

JP 2009-248600 A Japanese Patent Laid-Open No. 2007-306771 JP 2009-227097 A JP 2007-118696 A

  In an apparatus such as the background art described above, the electric motor is typically controlled to balance the power balance. However, there is a possibility that the balance of power balance may be lost due to the shift of the transmission. Then, there is a technical problem that the power storage device (battery) may be overpowered and durability of the power storage device may be reduced.

  The present invention has been made in view of the above-described problems, for example, and an object of the present invention is to propose a power transmission device that can suppress a decrease in durability of the power storage device.

  In order to solve the above-described problems, a first power transmission device of the present invention has a differential mechanism, a first rotating element of the differential mechanism is connected to a first motor, and a second of the differential mechanism. An electric differential unit in which a rotating element is connected to an internal combustion engine, a third rotating element of the differential mechanism is connected to a second electric motor, and a differential state of the differential mechanism is controlled by the first electric motor; A stepped transmission unit connected to the electric differential unit, an electric storage that can supply electric power to the first electric motor and the second electric motor, and can be charged by regenerative electric power of the first electric motor and the second electric motor A device is interposed between the first electric motor, the second electric motor, and the power storage device to transfer power between the first electric motor, the second motor, and the power storage device, and to adjust the voltage. Voltage adjustment means and when the power transfer is restricted, Control for controlling the voltage adjusting means to change the voltage when the power transmission / reception exceeds a limit relating to the power transmission / reception during the gear shifting due to execution of the gear shifting of the stepped transmission unit. Means.

  According to the first power transmission device of the present invention, the electric differential section has a differential mechanism, and a first rotating element (for example, a sun gear) of the differential mechanism is connected to the first electric motor, A second rotating element (for example, a planetary carrier) of the differential mechanism is connected to the internal combustion engine, and a third rotating element (for example, a ring gear) of the differential mechanism is connected to the second electric motor. The differential state of the differential mechanism is controlled by the first electric motor.

  For example, a power storage device such as a nickel metal hydride battery or a lithium ion battery can supply power to the first motor and the second motor, and can be charged by regenerative power of the first motor and the second motor.

  For example, a voltage adjusting means such as an inverter is interposed between the first motor and the second motor and the power storage device, performs power transfer between the first motor and the second motor and the power storage device, and adjusts the voltage. Is possible.

  For example, the control means including a memory, a processor, and the like is configured such that when power transmission / reception is restricted, power transmission / reception is related to the power transmission / reception during gear shifting due to execution of gear shifting of the stepped transmission unit. The voltage adjusting means is controlled to change the voltage on condition that the limit is exceeded.

  “When power transfer is restricted” means, for example, when the storage device is restricted in discharging or charging, or the like. The “restriction related to power transfer” means, for example, the upper limit value of the discharge limit when the discharge of the power storage device is restricted, and the upper limit value of the charge limit when the charge of the power storage device is restricted. “The power transfer exceeds the limit related to the power transfer” means, for example, that the power output from the power storage device exceeds the upper limit of the discharge limit when the discharge of the power storage device is limited. When the charging of the device is restricted, it means that the electric power input to the power storage device exceeds the upper limit value of the charging restriction.

  According to the inventor's research, the following matters have been found. That is, generally, the first electric motor and the second electric motor are controlled so as to balance the power balance of the power storage device. However, due to the shift of the stepped transmission unit, for example, if the rotation speed of the second motor changes relatively quickly, the balance of power balance may be lost. Furthermore, for example, if the step-up control or step-down control due to the target torque of the second motor and the shift of the stepped transmission unit are performed at the same time, there is a possibility that the balance of the power balance will be greatly broken. Then, there is a possibility that the power output from the power storage device exceeds the upper limit value of the discharge limit, or the power input to the power storage device exceeds the upper limit value of the charge limit. As a result, the voltage of the power storage device becomes a predetermined value or less or a predetermined value or more, and the durability of the power storage device may be reduced.

  However, in the present invention, when the power transmission / reception is restricted by the control means, the power transmission / reception exceeds the restriction on the power transmission / reception during the gear shifting due to the execution of the shift of the stepped transmission unit. The voltage adjusting means is controlled so as to change the voltage on the condition. Specifically, for example, the voltage adjustment is performed by the control means so that the voltage is changed before the step change of the stepped transmission unit so that the step-up control or the step-down control and the step change transmission unit are not performed at the same time. Means are controlled. Alternatively, the voltage adjusting means is controlled by the control means so as to change the voltage stepwise so that the voltage of the power storage device does not change suddenly.

  For this reason, the fluctuation | variation of the voltage resulting from the gear shift of a stepped transmission part can be suppressed. As a result, it is possible to suppress the voltage of the power storage device from being equal to or lower than the predetermined value or higher than the predetermined value, and it is possible to suppress a decrease in durability of the power storage device.

  In one aspect of the first power transmission device of the present invention, the control means controls the voltage adjusting means so as to change the voltage according to the voltage of the power storage device.

  According to this aspect, since the voltage can be appropriately boosted or lowered, each of the first motor and the second motor can output the target torque.

  In another aspect of the first power transmission device of the present invention, the control means transmits and receives the power during the shift due to the shift being performed when the power transfer is restricted. When the voltage exceeds the limit, the output adjusting means changes the output gradient of at least one of the first electric motor and the second electric motor, and changes the voltage according to the changed output gradient. Control.

  According to this aspect, it is possible to suppress a sudden change in the output of at least one of the first electric motor and the second electric motor. In addition, it is possible to shift the timing of the power balance fluctuation caused by the output fluctuation of at least one of the first motor and the second motor and the power balance fluctuation caused by the voltage change by the voltage adjusting means.

  In this aspect, first, the balance of the power balance is maintained by changing the output gradient of at least one of the first motor and the second motor. If it is difficult to maintain the balance of power balance even if the output gradient of at least one of the first motor and the second motor is changed, the balance of the power balance can be adjusted by changing the voltage using the voltage adjusting means. Maintenance is planned.

  Therefore, “control the voltage adjusting means to change the voltage according to the changed output gradient” means that, for example, when the balance of power balance can be maintained by changing the output gradient, the voltage is When the voltage adjustment means is controlled so as not to change, and when it is difficult to maintain the balance of power balance by changing the output gradient, the voltage adjustment means is changed so as to change the voltage in order to maintain the balance of power balance. Is controlled.

  Note that “changing the output gradient” means changing the change rate of the target (command) torque of at least one of the first motor and the second motor. Specifically, for example, the time constant of fluctuation of the target torque may be changed, or the change rate of the target torque may be changed according to the power limit amount of the power storage device, the power balance margin, the vehicle load, or the like.

  Alternatively, in another aspect of the first power transmission device of the present invention, the control means causes the shift to be performed during the shift due to the shift being performed when the power transfer is restricted. The voltage adjusting means is controlled to change the voltage before the shift on condition that the power transfer exceeds the limit.

  According to this aspect, since the voltage is changed by the voltage adjusting means before the step change of the stepped transmission unit, the rotation speed change of each of the first motor and the second motor due to the shift of the stepped transmission unit, the voltage The timing of the voltage change by the adjusting means can be shifted. As a result, a rapid change in the balance of the power balance can be suppressed, and a decrease in durability of the power storage device can be suppressed.

  In order to solve the above-described problem, the second power transmission device of the present invention has a differential mechanism, the first rotating element of the differential mechanism is connected to the first electric motor, and the second of the differential mechanism An electric differential unit in which a rotating element is connected to an internal combustion engine, a third rotating element of the differential mechanism is connected to a second electric motor, and a differential state of the differential mechanism is controlled by the first electric motor; A stepped transmission unit connected to the electric differential unit, an electric storage that can supply electric power to the first electric motor and the second electric motor, and can be charged by regenerative electric power of the first electric motor and the second electric motor A device is interposed between the first electric motor, the second electric motor, and the power storage device to transfer power between the first electric motor, the second motor, and the power storage device, and to adjust the voltage. Voltage adjustment means and when the power transfer is restricted, The voltage is changed so that the voltage is changed before the shift on condition that the power transfer during the shift exceeds a limit related to the power transfer due to execution of the shift of the stepped transmission unit. Control means for controlling the adjusting means.

  According to the 2nd power transmission device of the present invention, like the 1st power transmission device of the present invention mentioned above, the fall of the endurance of an electrical storage device can be controlled.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a skeleton diagram explaining the composition of the power transmission device concerning a 1st embodiment. It is an operation | movement chart explaining the relationship between the speed change operation | movement in case the stepped transmission part of the power transmission device which concerns on 1st Embodiment is operated, and the action | operation combination of the hydraulic friction engagement apparatus used for it. It is a collinear diagram explaining the relative rotational speed of each gear stage when the power transmission device according to the first embodiment is operated. It is a figure explaining the input-output signal of the electronic controller provided in the power transmission device which concerns on 1st Embodiment. An example of a switching diagram stored in advance and used for determination of the shift state of the stepped transmission unit, which is configured in the same two-dimensional coordinates using the vehicle speed and the output torque as parameters, and switching between engine travel and motor travel It is a figure which illustrates the driving force source switching diagram memorize | stored beforehand which has the boundary line used for determination. It is an example of the shift operation apparatus operated in order to select multiple types of shift positions provided with the shift lever. It is a flowchart explaining the principal part of the shift control operation | movement by the electronic controller which concerns on 1st Embodiment. FIG. 8 is a time chart for explaining a shift control operation shown in the flowchart of FIG. 7. FIG. It is a time chart explaining the gear shift control operation concerning the modification of a 1st embodiment. It is a flowchart explaining the principal part of the shift control operation | movement by the electronic controller which concerns on 2nd Embodiment. It is an example of the map which defines the relationship between a battery power limit value and a rate processing time constant. 11 is a time chart for explaining a shift control operation shown in the flowchart of FIG. 10.

  Embodiments of a power transmission device according to the present invention will be described below with reference to the drawings.

<First Embodiment>
A power transmission device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 8.

(Configuration of power transmission device)
First, the configuration of the power transmission device according to the present embodiment will be described with reference to FIG. FIG. 1 is a skeleton diagram illustrating the configuration of the power transmission device according to the present embodiment. Since the power transmission device is configured symmetrically with respect to its axis, the lower side is omitted in the skeleton diagram of FIG.

  In FIG. 1, a power transmission device 1 has a common shaft in a transmission case 14 (hereinafter referred to as “case 14” as appropriate) as a non-rotating member attached to a vehicle body of a hybrid vehicle on which the power transmission device 1 is mounted. As an input rotation member arranged on the heart and connected directly to the engine (ENG) 10 which is a main power source or indirectly via a pulsation absorbing damper (that is, a vibration damping device) not shown. In the power transmission path between the input shaft 101, the continuously variable transmission 21 connected to the input shaft 101, and the continuously variable transmission 21 and drive wheels (not shown), a transmission member is connected to the continuously variable transmission 21. (I.e., a stepped transmission unit 22 connected in series via a transmission shaft) 102 and an output shaft 103 as an output rotating member that transmits the output of the stepped transmission unit 22 to the subsequent stage. To have. That is, the power transmission device 1 includes a continuously variable transmission unit 21 and a stepped transmission unit 22 provided in series.

  Since the axial dimension of the power transmission device 1 is relatively large, the power transmission device 1 is suitably used for, for example, an FR (Front-engine Rear-drive) type vehicle that is vertically placed in the longitudinal direction of the vehicle. The power transmission device 1 is provided in a power transmission path from the engine 10 to a pair of drive wheels, and the power output from the engine 10 is converted into a differential gear device (that is, a final reduction gear) that constitutes a part of the power transmission path. Machine) (not shown) and a pair of axles, etc., are sequentially transmitted to the pair of drive wheels.

  The engine 10 is a main power source for driving the vehicle, and is constituted by an internal combustion engine such as a gasoline engine or a diesel engine. As shown in FIG. 1, in the power transmission device 1, the engine 10 is directly connected to a continuously variable transmission 21. Here, “directly connected” means that they are connected without using a hydraulic power transmission device such as a torque converter or a fluid coupling. For example, the connection via the pulsation absorbing damper described above is “directly connected”. included.

  The continuously variable transmission 21 includes a planetary gear mechanism 24, a first electric motor M1, and a second electric motor M2. The planetary gear mechanism 24 includes a sun gear S0, a pinion gear, a carrier CA0 that supports the pinion gear so that it can rotate and revolve, and a ring gear R0.

  The first electric motor M1 is provided such that its rotor rotates integrally with the sun gear S0 of the planetary gear mechanism 24. The second electric motor M2 is provided such that its rotor rotates integrally with the ring gear R0 of the planetary gear mechanism 24. The stators of the first electric motor M1 and the second electric motor M2 are connected to the case 14, respectively. Note that the second electric motor M2 may be provided in any portion that constitutes a power transmission path from the transmission member 102 to the drive wheel.

  The first electric motor M1 is an electric motor having at least a generator (power generation) function for generating a reaction force, and the second electric motor M2 is a motor (electric motor) function for outputting a driving force as a driving power source for traveling. Is an electric motor having at least The first electric motor M1 and the second electric motor M2 are preferably so-called motor generators that also have a power generation function.

  In the continuously variable transmission unit 21, the carrier CA0 is connected to the input shaft 101, that is, the engine 10, the sun gear S0 is connected to the first electric motor M1, and the ring gear R0 is connected to the transmission member 102. In the continuously variable transmission 21, the sun gear S0, the carrier CA0, and the ring gear R0 can rotate relative to each other. For this reason, regardless of the rotational speed of the engine 10, the rotational speed of the transmission member 102 continuously changes, that is, a continuously variable transmission state is established.

  The first electric motor M1 and the second electric motor M2 are electrically connected to the power storage device 12 such as a nickel metal hydride battery or a lithium ion battery via the inverter 11. The power storage device 12 can supply power to the first motor M1 and the second motor M2, and can be charged by regenerative power of the first motor M1 and the second motor M2.

  The “engine 10”, “inverter 11”, “continuously variable transmission 21”, “sun gear S0”, “carrier CA0”, and “ring gear R0” according to the present embodiment are the “internal combustion engine” according to the present invention. ”,“ Voltage adjusting means ”,“ electric differential unit ”,“ first rotating element ”,“ second rotating element ”, and“ third rotating element ”.

  The stepped transmission unit 22 includes planetary gear mechanisms 25, 26, and 27. The planetary gear mechanism 25 includes a sun gear S1, a pinion gear, a carrier CA1 that supports the pinion gear so that it can rotate and revolve, and a ring gear R1. The planetary gear mechanism 26 includes a sun gear S2, a pinion gear, a carrier CA2 that supports the pinion gear so that it can rotate and revolve, and a ring gear R2. The planetary gear mechanism 27 includes a sun gear S3, a pinion gear, a carrier CA3 that supports the pinion gear so that it can rotate and revolve, and a ring gear R3.

  In the stepped transmission 22, the sun gears S <b> 1 and S <b> 2 that are integrally connected to each other are selectively connected to the transmission member 102 via the first clutch C <b> 1 and the case 14 via the first brake B <b> 1. To be selectively connected. The carrier CA1 is selectively coupled to the case 14 via the second brake B2. The ring gear R1 and the carriers CA2 and CA3 that are integrally connected to each other are connected to the output shaft 103. The ring gear R2 and the sun gear S3 that are integrally connected to each other are selectively connected to the transmission member 102 via the second clutch C2. Ring gear R3 is selectively coupled to case 14 via third brake B3.

  The first clutch C1, the second clutch C2, the first brake B1, the second brake B2, and the third brake B3 are hydraulic friction engagement devices that are engagement elements often used in known vehicle transmissions. Except for the first brake B1, this is a wet multi-plate type engaging device in which a plurality of friction plates stacked on each other are pressed by a hydraulic actuator, but the first brake B1 is wound around the outer peripheral surface of the rotating drum. In addition, one or two bands have one end constituted by a band brake tightened by a hydraulic actuator, and selectively connect members on both sides in which they are inserted.

  In the stepped transmission 22 configured as described above, for example, as shown in the engagement operation table of FIG. 2, the first clutch C1, the second clutch C2, the first brake B1, the second brake B2, and the second clutch By selectively engaging the three brakes B3, one of the first gear ratio (ie, the first gear) to the fourth gear ratio (ie, the fourth gear), the reverse gear ( In other words, a reverse gear) or neutral is selectively established, and a predetermined gear ratio (that is, input shaft rotational speed / output shaft rotational speed) is obtained for each gear stage.

  As shown in FIG. 2, the first shift gear stage having a gear ratio of, for example, “3.357” is established by the engagement of the first clutch C1 and the third brake B3. As a result of the engagement of the first clutch C1 and the second brake B2, a second transmission gear stage having a gear ratio of, for example, “2.180” is established. With the engagement of the first clutch C1 and the first brake B1, a third transmission gear stage with a gear ratio of, for example, “1.424” is established. As a result of the engagement of the first clutch C1 and the second clutch C2, a fourth transmission gear stage having a gear ratio of, for example, “1.000” is established. Due to the engagement of the first clutch C1 and the third brake B3, a reverse gear for motor traveling with a gear ratio of, for example, “3.209” is established. Due to the engagement of the second clutch C2 and the third brake B3, a reverse gear for engine traveling having a gear ratio of, for example, “3.209” is established. In the neutral (N) state, none of the first clutch C1, the second clutch C2, the first brake B1, the second brake B2, and the third brake B3 is engaged.

  In FIG. 2, the gear ratios of the respective gear speeds adjacent to each other are changed in an equal ratio, which is ideal for the stepped gear shift, and the change ratio between the gear speeds of each gear speed (that is, the gear ratio step). ) Is almost constant. That is, the gear ratio step between the first transmission gear stage and the second transmission gear stage is 1.54, and the gear ratio step between the second transmission gear stage and the third transmission gear stage is 1.53. Yes, the gear ratio step between the third transmission gear stage and the fourth transmission gear stage is 1.42. The overall gear width (that is, the gear ratio step between the first transmission gear stage and the fourth transmission gear stage) is set to a relatively large value of 3.36.

  FIG. 3 is a collinear diagram that can represent on a straight line the relative relationship between the rotational speeds of the rotating elements that are connected in different gear stages. The alignment chart of FIG. 3 shows the relative relationship of the gear ratios of the planetary gear mechanisms 24, 25, 26 and 27 in the horizontal axis direction, and shows the relative rotational speed in the vertical axis direction.

  In FIG. 3, of the two horizontal lines X 1 and X 2, the horizontal line X 1 indicates the rotational speed zero, and the horizontal line X 2 indicates the rotational speed “1.0”, that is, the rotational speed of the transmission member 102. On the other hand, the eight vertical lines, in order from the left, are sun gear S0, carrier CA0, ring gear R0, sun gears S1 and S2 connected to each other, carrier CA1, ring gear R3, ring gear R1 connected to each other, carriers CA2 and CA3, and The relative rotational speed ratios of the sun gear S3 and the ring gear R2 connected to each other are shown.

  The intervals between the vertical lines are determined according to the gear ratios of the planetary gear mechanisms 24, 25, 26 and 27, respectively. That is, as shown in FIG. 3, for each planetary gear mechanism 24, 25, 26 and 27, when the distance between the sun gear and the carrier is 1.000, the distance between the carrier and the ring gear corresponds to ρ. It becomes.

  In FIG. 3, the carrier CA0 of the planetary gear mechanism 24 is connected to the input shaft 101, the sun gear S0 is connected to the first electric motor M1, and the ring gear R0 is connected to the second electric motor M2 and to the transmission member 102. The sun gear S1 of the planetary gear mechanism 25 and the sun gear S2 of the planetary gear mechanism 26 that are integrally connected to each other are selectively connected to the transmission member 102 via the second clutch C2, and the first brake B1 is connected. And selectively coupled to the case 14. The carrier CA1 of the planetary gear mechanism 25 is selectively connected to the case 14 via the second brake B2. The ring gear R3 of the planetary gear mechanism 27 is selectively connected to the case 14 via the third brake B3. The ring gear R1 of the planetary gear mechanism 25, the carrier CA2 of the planetary gear mechanism 26, and the carrier CA3 of the planetary gear mechanism 27 that are integrally connected to each other are connected to the output shaft 103. The ring gear R2 of the planetary gear mechanism 26 and the sun gear S3 of the planetary gear mechanism 27 that are integrally connected to each other are selectively connected to the transmission member 102 via the first clutch C1.

  FIG. 4 shows a signal input to an electronic control unit (ECU) 30 that is a control device for controlling the power transmission device 1 according to the present embodiment and a signal output from the electronic control device 30. Illustrated. The electronic control unit 30 includes a so-called microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output interface, and the like, and has a temporary storage function of the RAM. Performing drive control such as hybrid drive control for the engine 10, the first electric motor M1 and the second electric motor M2, and the shift control for the stepped transmission unit 22 by performing signal processing in accordance with a program stored in advance in the ROM while being used It is.

  The electronic control unit 30 indicates the signal indicating the engine water temperature, the signal indicating the Pb1 oil pressure, the signal indicating the Pb2 oil pressure, the signal indicating the Pc2 oil pressure, and the number of rotations of the first electric motor M1 from the sensors and switches shown in FIG. Signal, signal indicating the rotational speed of the second electric motor M2, signal indicating the engine rotational speed, signal indicating the state of the towing switch, signal for instructing the M mode (manual shift running mode), signal indicating the operation of the air conditioner, output shaft A vehicle speed signal corresponding to the rotational speed of 103, a signal indicating the hydraulic oil temperature of the stepped transmission unit 22, a signal for instructing ECT (Electronic Controlled Transmission), a signal indicating a side brake operation, a signal indicating a foot brake operation, a catalyst temperature , An accelerator opening signal indicating the amount of operation of the accelerator pedal, EV (Electri c Vehicle) switch state signal, snow mode setting signal, vehicle longitudinal acceleration signal, auto cruise travel signal, power mode switch state signal, shift position signal, etc. Supplied respectively.

  On the other hand, the electronic control unit 30 commands the drive signal to the throttle actuator that operates the throttle valve opening, the signal for adjusting the boost pressure, the signal for operating the electric air conditioner, and the ignition timing of the engine 10. An ignition signal to be activated, a signal to command the operation of the first electric motor M1, a signal to command the operation of the second electric motor M2, a signal to control the first power storage device, a signal to control the second power storage device, and a gear ratio indicator to be operated A signal for displaying that it is in the snow mode, a command signal for operating an electromagnetic valve included in the hydraulic control circuit to control the hydraulic actuator of the hydraulic friction engagement device of the stepped transmission unit 22, Signal for operating an ABS (Antilock Break System) actuator to prevent wheel slippage during braking, M mode Is displayed, a signal for operating the electric hydraulic pump that is the hydraulic power source of the hydraulic control circuit, a signal for driving the electric heater, a signal to the computer for cruise control control, etc. are output respectively. The

  The electronic control unit 30 executes automatic transmission control of the continuously variable transmission unit 21 and the stepped transmission unit 22. Here, the automatic shift control of the stepped transmission unit 22 is executed based on the vehicle state indicated by the vehicle speed and the required output torque from the shift diagram as shown in FIG. Is done. At this time, the electronic control unit 30 outputs a command for engaging and / or releasing the engagement device or the like involved in the shift so that the shift stage is achieved according to, for example, the engagement table shown in FIG.

  FIG. 5 shows an example of a switching diagram stored in advance and used for determination of the shift state of the stepped transmission unit, which is composed of two-dimensional coordinates using vehicle speed and output torque as parameters, and engine travel and motor travel. It is a figure which illustrates the driving force source switching diagram memorize | stored previously which has the boundary line used for switching determination with. In FIG. 5, a solid line indicates an upshift line, and a broken line indicates a downshift line.

  The solid line E in FIG. 5 is a paraphrase for switching the driving force source for starting and running the hybrid vehicle (hereinafter referred to as “running” as appropriate) between the engine 10 and the electric motor (for example, the second electric motor M2). For example, so-called engine travel that starts and travels the hybrid vehicle using the engine 10 as a driving power source for travel (hereinafter referred to as “travel” as appropriate), and travels the hybrid vehicle using the second electric motor M2 as a driving power source for travel. This is a boundary line between the engine traveling region and the motor traveling region (shaded portion in FIG. 5) for switching between so-called motor traveling.

  The electronic control unit 30 determines whether the motor traveling region or the engine traveling region is based on the vehicle state indicated by the vehicle speed and the required output torque from the driving force source switching diagram as shown in FIG. 5, for example. Determination is made and motor running or engine running is executed. As is apparent from FIG. 5, the motor running is a relatively low output torque range in which the engine efficiency is generally lower than the high torque range, that is, a low engine torque range, or a relatively low vehicle speed. It is executed in the vehicle speed range, that is, in the low load range. Therefore, normally, the motor start is executed in preference to the engine start. For example, when the vehicle starts, the accelerator pedal is depressed so that the required output torque exceeding the motor travel range in FIG. In such a vehicle state, the engine start is also normally executed.

  FIG. 6 is a diagram illustrating an example of a shift operation device operated to select a plurality of types of shift positions including a shift lever. The shift switching device includes, for example, a shift lever 48 that is disposed beside the driver's seat and is operated to select a plurality of types of shift positions. The shift lever 48 is in a neutral state in which the power transmission path in the power transmission device 1 (stepped transmission 22) is interrupted so that neither of the first clutch C1 and the second clutch C2 is engaged. That is, the neutral position and the parking position “P (parking)” for locking the output shaft 103 of the stepped transmission unit 22, the reverse traveling position “R (reverse)” for reverse traveling, The neutral position “N (neutral)”, the forward automatic shift travel position “D (drive)”, or the forward manual shift travel position “M (manual)” to be in a neutral state where the power transmission path is interrupted is manually operated. It is configured.

(Shift control)
Next, the shift control process executed by the electronic control unit 30 during the traveling of the hybrid vehicle on which the power transmission device 1 configured as described above is mounted will be described with reference to the flowchart of FIG. .

  In FIG. 7, first, the electronic control unit 30 determines whether or not the amount of power of the power storage device 12 is limited (step S101). Specifically, the electronic control unit 30 is in a Win limited state in which the charging power of the power storage device 12 is limited, and is in a Wout limited state in which the discharge power of the power storage device 12 is limited. Determine whether.

  When it is determined that the amount of power of the power storage device 12 is not restricted (step S101: No), the process returns to stop and enters a standby state. That is, until the next processing start time that is uniquely determined by a predetermined cycle is reached, the execution of the processing in step S101 is stopped and a standby state is entered.

  On the other hand, when it is determined that the amount of power of the power storage device 12 is limited (step S101: Yes), the electronic control device 30 determines whether or not a specific shift occurs (step S102). Here, the “specific shift” is a state in which the power transmission / reception balance between the first motor M1 and the second motor M2 is shifted with the shift of the stepped transmission unit 22, and the power cannot be taken in and out of the power storage device 12. This means a gear shift that occurs.

  If it is determined that the specific shift does not occur (step S102: No), the process returns to stop and enters a standby state. On the other hand, when it is determined that a specific shift occurs (step S102: Yes), the electronic control unit 30 determines whether or not the boost switching control occurs simultaneously during the shift of the stepped transmission unit 22 (step S103). .

  When it is determined that the step-up switching control is simultaneously generated during the shift of the stepped transmission unit 22 (step S103: Yes), the electronic control unit 30 is before the shift of the stepped transmission unit 22 (for example, simultaneously with the shift determination). Step-up switching control is performed (that is, the inverter 11 is controlled to increase the voltage) (step S104).

  If the boost switching control affects the inertia phase, the time from the shift determination to the shift signal output may be delayed to delay the execution of the shift, that is, the generation of the inertia phase. Alternatively, the boost switching control may be performed before the shift determination.

  On the other hand, when it is determined that the step-up switching control does not occur simultaneously during the shift of the stepped transmission unit 22 (step S103: No), the electronic control unit 30 performs the shift of the stepped transmission unit 22 (step S105). .

  The “electronic control device 30” according to the present embodiment is an example of the “control unit” according to the present invention. In the present embodiment, a part of the electronic control device 30 for various electronic controls of the hybrid vehicle is used as a part of the power transmission device 1.

  Next, time changes such as the power balance when the above-described shift control process is executed will be described with reference to the time chart of FIG. FIG. 8 is a time chart for explaining the shift control operation shown in the flowchart of FIG. 7, where the stepped transmission unit 22 is caused by the Wout restricted state and the driver of the hybrid vehicle performing the accelerator operation. It is an example of the time chart at the time of downshift.

  In FIG. 8, it is determined whether or not the electric power of the power storage device 12 is restricted by the electronic control device 30 at time t1, the driver operates the accelerator pedal at time t2, and the electronic control device 30 at time t3. It is assumed that the shift determination is made, the shift of the stepped transmission unit 22 is started at time t4, and the shift of the stepped transmission unit 22 is completed at time t5.

  When the driver depresses the accelerator pedal (or increases the depressing amount of the accelerator pedal) at time t2 in FIG. 8, the accelerator opening increases. Thereafter, the number of revolutions of the engine 10 increases in response to the accelerator pedal being depressed.

  Further, due to the downshift of the stepped transmission unit 22, the rotational speed of the second electric motor M2 connected to the input shaft (that is, the transmission member 102) of the stepped transmission unit 22 (that is, MG2 rotational speed). Rises. Further, the hydraulic pressure of the stepped transmission unit 22 is changed from the time when a shift is requested (time t3 in this case) in accordance with predetermined hydraulic control, and the shift of the stepped transmission unit 22 is advanced. Note that “Pb1” and “Pb3” in the transmission hydraulic pressure in FIG. 8 indicate “release pressure” and “engagement pressure”, respectively.

  Here, the torque of the second electric motor M2 (that is, the MG2 torque) is set to a high torque in order to reduce the backlash until the driving force is generated by the inertia torque generated from the change in the rotation speed of the second electric motor M2. . At this time, the power balance of the power storage device 12 (that is, the battery power balance) changes to the discharge side.

  In such a case, normally, the inverter 11 is controlled so as to boost the voltage at the timing when the second electric motor M2 outputs a high torque. Then, since electric power is consumed when boosting starts, the power balance of power storage device 12 changes to the discharge side. If the discharge due to the change in the rotation speed of the second electric motor M2 and the discharge due to the boost by the inverter 11 overlap during the shifting of the stepped transmission unit 22, for example, as shown by a broken line in FIG. The power balance of the power storage device 12 changes greatly. For this reason, there exists a possibility that durability of the electrical storage apparatus 12 may fall.

  However, in the present embodiment, the electronic control unit 30 controls the inverter 11 so as to boost the voltage simultaneously with the shift determination before the step change of the stepped transmission unit 22 (that is, at time t3) (in the inverter boost voltage). (See solid line). For this reason, it is possible to avoid the discharge caused by the boosting by the inverter 11 and the discharge caused by the change in the rotation speed or torque of the second electric motor M2. For this reason, the fall of durability of the electrical storage apparatus 12 can be suppressed.

  The inverter boost voltage in FIG. 8 is calculated from the load factor of the larger load factor of the first motor M1 and the load factor of the second motor M2. Then, the value of the inverter boost voltage becomes the voltage value of each of the first electric motor M1 and the second electric motor M2.

  Note that the voltage boosting by the inverter 11 may be performed after the gear shifting of the stepped transmission unit 22 instead of being performed before the gear shifting of the stepped transmission unit 22.

  By the way, when the amount of power of the power storage device 12 is not limited, even if the power balance of the power storage device 12 becomes unbalanced, the power storage device 12 can absorb the unbalance. The discharge resulting from the change in the rotational speed of M2 and the discharge resulting from the boosting by the inverter 11 may overlap, that is, the shifting of the stepped transmission unit 22 and the boosting control may be performed simultaneously.

  Further, even when the power amount of the power storage device 12 is limited, if the power balance of the power storage device 12 does not become unbalanced, the gear shifting of the stepped transmission unit 22 and the boost control are performed simultaneously. Also good.

<Modification>
Next, a shift control process according to a modification of the present embodiment will be described with reference to the time chart of FIG. FIG. 9 is a time chart for explaining the shift control operation according to the modification of the present embodiment having the same meaning as in FIG. 8, and is caused by the Wout restricted state and the driver of the hybrid vehicle performing the accelerator operation. And it is an example of the time chart at the time of the stepped transmission part 22 downshifting.

  In FIG. 9, it is determined whether or not the electric power of the power storage device 12 is restricted by the electronic control device 30 at time t1, the accelerator pedal is operated by the driver at time t2, and the electronic control device 30 at time t3. It is assumed that the shift determination is made, the shift of the stepped transmission unit 22 is started at time t4, and the shift of the stepped transmission unit 22 is completed at time t5.

  In this modified example, in step S104 shown in FIG. 7, instead of “the electronic control device 30 performs the step-up switching control before the gear change of the stepped transmission unit 22”, “the electronic control device 30 The step-up switching control is executed step by step during the shift of the step transmission unit 22. "

  Specifically, as shown in FIG. 9, the voltage suddenly increases by limiting the load factor of the second electric motor M2 and releasing the limitation stepwise (see the solid line in the MG2 load factor). (Refer to the solid line in the inverter boost voltage).

  By releasing the restriction on the load factor of the second electric motor M2 in stages, it is possible to suppress power consumption at the start of boosting, and thus it is possible to suppress a large change in the power balance of the power storage device 12. For this reason, the fall of durability of the electrical storage apparatus 12 can be suppressed.

  In the shift control process according to the present modification, for example, when the shift request of the stepped transmission unit 22 is requested, it is determined that the boost control is not necessary based on the load factor calculated from the rotation speed and torque of the second electric motor M2. However, even if boost control is necessary due to changes in the rotation speed or torque of the second electric motor M2 due to excessive shifting of the stepped transmission 22 and changes in the accelerator opening or gradient, A decrease in the durability of the device 12 can be suppressed, which is very advantageous in practice.

  Note that the limit of the load factor of the second electric motor M2 may be set as a value such that the power balance of the power storage device 12 is not unbalanced by the shift and boost control of the stepped transmission unit 22, for example.

Second Embodiment
A second embodiment of the power transmission device of the present invention will be described with reference to FIGS. The second embodiment is the same as the configuration of the first embodiment except that the shift control process executed by the electronic control unit 30 is different. Therefore, in the second embodiment, the description overlapping with that of the first embodiment is omitted, and the common portions in the drawings are denoted by the same reference numerals, and only the differences are basically illustrated in FIGS. The description will be given with reference.

(Shift control)
In FIG. 10, first, the electronic control unit 30 determines whether or not the amount of power of the power storage device 12 is limited (step S201). If it is determined that the amount of power of the power storage device 12 is not restricted (step S201: No), the process returns to stop and enters a standby state.

  On the other hand, when it is determined that the amount of power of the power storage device 12 is limited (step S201: Yes), the electronic control device 30 determines whether or not a specific shift occurs (step S202). If it is determined that the specific shift does not occur (step S202: No), the process returns to stop and enters a standby state.

  On the other hand, when it is determined that a specific shift occurs (step S202: Yes), the electronic control unit 30 instructs at least one of the first electric motor M1 and the second electric motor M2 due to the shift of the stepped transmission unit 22. It is determined whether or not the torque changes suddenly (step S203).

  When it is determined that the command torque changes abruptly (step S203: Yes), the electronic control unit 30 performs rate processing on the command torque related to the motor that is determined that the command torque changes suddenly, and performs the rate processing. The commanded torque is output (step S204).

  Here, the rate value related to the rate processing is determined from a map having parameters such as the power limit value (battery power limit value) of the power storage device 12 and the rate processing time constant as shown in FIG. Specifically, for example, when the power of the power storage device 12 is limited, a large time constant is set to suppress a sudden change in the command torque, thereby suppressing the power balance from becoming unbalanced. Further, when the vehicle load change amount is large, the power balance imbalance becomes large, and therefore the time constant is increased. On the other hand, when there is a margin in the power balance, the time constant is lowered.

  FIG. 11 is an example of a map that defines the relationship between the battery power limit value and the rate processing time constant.

  On the other hand, when it is determined that the command torque does not change suddenly (step S203: No), the electronic control unit 30 outputs the command torque as it is (step S205). Even when it is determined that the command torque does not change suddenly, rate processing may be performed in order to balance the power balance of the power storage device 12.

  Next, time changes such as the power balance when the shift control process described above is executed will be described with reference to the time chart of FIG. FIG. 12 is a time chart for explaining the shift control operation shown in the flowchart of FIG. 10, and is an example of a time chart when the Wout limited state and the stepped transmission 22 are upshifted.

  In FIG. 12, it is determined whether or not the electric power of the power storage device 12 is limited by the electronic control device 30 at time t1, a shift determination is performed by the electronic control device 30 at time t2, and the stepped transmission unit at time t3. It is assumed that the shift 22 is started and the shift of the stepped transmission 22 is completed at time t4.

  Here, since the upshift of the stepped transmission unit 22 is performed using the inertia cancel control of the first electric motor M1, the first shift is performed simultaneously with the start of shifting of the stepped transmission unit 22 (that is, the start of the inertia phase). An inertia cancel torque for canceling the inertia of the electric motor M1 is commanded (see the broken line in the MG1 command torque).

  In the present embodiment, when it is determined by the electronic control device 30 that the command torque of the first electric motor M1 changes suddenly, a rate process is performed on the command torque of the first electric motor M1 in accordance with the restriction of the electric energy of the power storage device 12. That is, the output gradient of the first electric motor M1 is changed (see the solid line in the MG1 command torque).

  For this reason, it is possible to suppress the balance of the power balance from being lost due to the sudden change in output of the first electric motor M1. If it is predicted that the balance of power balance will be lost even if the command torque is subjected to rate processing, the electronic control device 30 controls the inverter 11 so as to change the voltage according to the command torque. It is possible to prevent the balance of balance from being lost.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. Is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Power transmission device, 10 ... Engine, 12 ... Power storage device, 21 ... Continuously variable transmission unit, 22 ... Stepped transmission unit, 24, 25, 26, 27 ... Planetary gear mechanism, 30 ... Electronic control unit, M1 ... 1 motor, M2 ... 2nd motor

Claims (5)

A differential mechanism, wherein a first rotating element of the differential mechanism is connected to a first electric motor, a second rotating element of the differential mechanism is connected to an internal combustion engine, and a third rotating element of the differential mechanism is An electric differential unit coupled to a second electric motor, wherein the differential state of the differential mechanism is controlled by the first electric motor;
A stepped transmission connected to the electric differential unit;
A power storage device capable of supplying electric power to the first electric motor and the second electric motor and capable of being charged by regenerative electric power of the first electric motor and the second electric motor;
Voltage adjustment that is interposed between the first electric motor, the second electric motor, and the power storage device, performs power transfer between the first electric motor, the second motor, and the power storage device, and adjusts a voltage. Means,
When the power transmission / reception is restricted, the voltage is changed when the power transmission / reception exceeds the power transmission / reception restriction during the gear shifting due to execution of a shift of the stepped transmission unit. And a control means for controlling the voltage adjusting means so as to change the power transmission device.   2. The power transmission device according to claim 1, wherein the control unit controls the voltage adjusting unit to change the voltage according to a voltage of the power storage device.   The control means, on condition that the power transfer exceeds the limit during the shift due to execution of the shift when the power transfer is limited. The output voltage gradient of at least one of the second electric motors is changed, and the voltage adjusting unit is controlled to change the voltage according to the changed output gradient. The power transmission device described.   When the power transfer exceeds the limit during the shift due to the execution of the shift when the power transfer is limited, the control means supplies the voltage before the shift. The power transmission device according to claim 1, wherein the voltage adjusting unit is controlled to be changed. A differential mechanism, wherein a first rotating element of the differential mechanism is connected to a first electric motor, a second rotating element of the differential mechanism is connected to an internal combustion engine, and a third rotating element of the differential mechanism is An electric differential unit coupled to a second electric motor, wherein the differential state of the differential mechanism is controlled by the first electric motor;
A stepped transmission connected to the electric differential unit;
A power storage device capable of supplying electric power to the first electric motor and the second electric motor and capable of being charged by regenerative electric power of the first electric motor and the second electric motor;
Voltage adjustment that is interposed between the first electric motor, the second electric motor, and the power storage device, performs power transfer between the first electric motor, the second motor, and the power storage device, and adjusts a voltage. Means,
When the power transmission / reception is restricted, the voltage is changed when the power transmission / reception exceeds the power transmission / reception restriction during the gear shifting due to execution of a shift of the stepped transmission unit. And a control means for controlling the voltage adjusting means so as to be changed before the shift.

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