JP2009096326A - Driving control device for oil pump unit and hybrid car equipped with the driving control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving control device of an oil pump unit, capable of reducing surplus oil supply to a power transmission mechanism, for the oil pump unit equipped with a mechanical oil pump and an electric oil pump, and a hybrid car equipped with the driving control device. <P>SOLUTION: This driving control device of the oil pump unit is configured to calculate oil required supply required for a power transmission mechanism from a vehicle speed, the output torque of a second motor generator and an oil temperature, and to calculate oil supply supplied from a mechanical oil pump MOP to the power transmission mechanism from the number of revolution of engine, oil temperature and oil pressure or the like, and to calculate oil under-supply quantity by subtracting oil supply from the oil required supply, and to control the number of revolution of an electric oil pump EOP so that oil discharge corrected so as to be increased in quantity only by correction quantity based on an oil temperature and an oil pressure or the like with respect to the oil under-supply quantity. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drive control device for an oil pump unit provided with a mechanical oil pump and an electric oil pump for supplying oil (such as hydraulic oil) to a power transmission mechanism provided in a hybrid vehicle or the like. The present invention also relates to a hybrid vehicle equipped with the drive control device for the oil pump unit. In particular, the present invention relates to a measure for optimizing the amount of oil supplied to the power transmission mechanism.

  For example, as disclosed in Patent Document 1 below, a hybrid drive device for a vehicle uses an internal combustion engine such as a gasoline engine or a diesel engine and an electric device such as a motor or a motor / generator as power sources. It is common. Further, there are various combinations of the internal combustion engine and the electric device, and the number of electric devices used is not limited to one, and there are some that use a plurality of electric devices.

  As one using two electric devices, for example, one disclosed in Patent Document 2 below is known. In this patent document, an engine and a first motor / generator are connected to each other via a power distribution mechanism including a single pinion type planetary gear mechanism. Further, torque is transmitted from the power distribution mechanism to the output member, and a second motor / generator is connected to the output member via a speed change mechanism (reduction mechanism). Thus, the output torque of the second motor / generator is added to the output member as so-called assist torque. Further, the speed change mechanism is constituted by a planetary gear mechanism that can select a direct connection state or a deceleration state by switching engagement / release of a friction engagement element (brake).

  A vehicle equipped with this type of hybrid drive system uses only an engine drive mode that drives only the engine and a motor / generator by controlling the drive / stop of the engine and motor / generator based on various conditions. The driving can be switched between a motor driving mode in which the motor / generator is driven as an electric motor and an engine / motor driving mode in which both the engine and the motor / generator are driven. Thereby, improvement of fuel consumption, reduction of noise, reduction of exhaust gas, and the like can be achieved. Further, by controlling the second motor / generator to the power running state or the regenerative state, a positive torque can be applied to the output member or a negative torque can be applied to the output member. Further, since the deceleration state can be set by the speed change mechanism, the second motor / generator can be reduced in torque or reduced in size.

By the way, in this type of hybrid vehicle, the engine is stopped in order to improve fuel consumption and reduce exhaust gas while traveling in the motor drive mode or when stopping at a signal or the like. When the engine is stopped, the mechanical oil pump that has been operated by the driving force of the engine is also stopped, and oil pressure for engaging the friction engagement elements of the transmission mechanism cannot be secured. In addition, there is a possibility that each part of the power transmission mechanism including the transmission mechanism cannot be sufficiently lubricated or cooled. For this reason, this type of hybrid vehicle is provided with an electric oil pump operable by an electric motor. In other words, even when the engine is stopped, the electric oil pump is driven to supply oil (ATF) to the power transmission mechanism, to ensure the hydraulic pressure for engaging the friction engagement elements, and to transmit power. Each part of the mechanism is sufficiently lubricated and cooled.
Japanese Patent Laid-Open No. 2004-256063 JP-A-2005-207304 JP 2003-240110 A JP 2001-80390 A

  As a conventional control of a general electric oil pump, one that switches ON / OFF in conjunction with driving / stopping of an engine and one that variably controls the rotation speed of an electric oil pump are known. For example, in the case where the rotational speed of the electric oil pump is variably controlled, when both the mechanical oil pump and the electric oil pump are driven, the engine speed rapidly decreases as the driver releases the accelerator operation. In other words, even if the oil discharge rate of the mechanical oil pump decreases rapidly, the electric oil pump speed is set high so that a sufficient amount of oil can be supplied to the power transmission mechanism. It was.

  Specifically, the rotational speed of the electric oil pump is controlled in accordance with a command map (a map for setting the rotational speed of the electric oil pump) stored in advance in the ECU. By setting the rotational speed of the electric oil pump to be high, it was set so as not to hinder the operation of the power transmission mechanism even when the oil discharge amount of the mechanical oil pump rapidly decreased.

  For this reason, the electric oil pump is controlled such that the actual oil supply amount is larger than the minimum necessary oil supply amount as a whole of the power transmission mechanism, and the excessive oil supply amount is continuously maintained. It was in a state.

  Thus, in the situation where the electric oil pump is driven more than necessary and the oil supply amount is excessive, not only wasteful energy loss (electric energy loss) in the electric oil pump increases, but also power transmission. Excessive oil inside the mechanism may greatly increase the stirring resistance of various rotating bodies (gears, motor rotors, etc.), leading to a decrease in output torque output to the drive wheels.

  The above problems are not only in the oil pump unit mounted on the hybrid vehicle, but also in a vehicle that uses only the engine as a drive source and performs idling stop control (see Patent Document 3 and Patent Document 4). It can happen as well. In other words, this type of vehicle also uses an electric oil pump to ensure hydraulic pressure while the engine is stopped by idling stop control. In this case, the electric oil pump is driven more than necessary and the oil supply amount is excessive. Could lead to a situation.

  Note that in Patent Document 1 and Patent Document 2 described above, the electric oil pump is driven and controlled so that the oil supply amount as a whole of the power transmission mechanism is not excessive or insufficient with respect to the oil supply amount from the mechanical oil pump. However, the specific method of the control content is not clear and is still insufficient in terms of practicality, and the specific method has been required.

  The present invention has been made in view of such a point, and an object of the present invention is to supply excess oil to a power transmission mechanism with respect to an oil pump unit including a mechanical oil pump and an electric oil pump. An object of the present invention is to provide an oil pump unit drive control device capable of reducing the amount and a hybrid vehicle equipped with the drive control device.

-Solving principle-
The solution principle of the present invention taken to achieve the above object is to subtract the amount of oil supplied to the power transmission mechanism from the mechanical oil pump from the amount of oil currently required for the power transmission mechanism. Thus, the shortage amount of the supply oil is calculated, and the electric oil pump is controlled so as to compensate only for this shortage amount. As a result, oil can be supplied to the power transmission mechanism without excess or deficiency.

-Solution-
Specifically, the present invention provides a power transmission mechanism for transmitting a driving force to drive wheels, in which an oil pump unit is constituted by a mechanical oil pump driven by an internal combustion engine and an electric oil pump driven by an electric motor. On the other hand, it is assumed that the oil pump unit drive control device supplies oil from the oil pump unit. The drive control device for the oil pump unit is provided with necessary supply amount recognition means, oil supply amount detection means, supply oil shortage calculation means, and electric oil pump control means. The required supply amount recognizing means obtains the required oil supply amount required for the power transmission mechanism. The oil supply amount detection means detects the oil supply amount supplied from the mechanical oil pump to the power transmission mechanism when the internal combustion engine is driven. The supply oil shortage calculating means subtracts the oil supply amount from the mechanical oil pump detected by the oil supply amount detection means from the oil required supply amount obtained by the required supply amount recognition means, Whether or not the supply oil is insufficient is determined. If the supply oil is insufficient, the supply oil shortage is calculated. When the supply oil shortage amount calculation means determines that the supply oil shortage amount is insufficient, the electric oil pump control means generates an oil amount substantially equal to the calculated supply oil shortage amount from the electric oil pump. The rotational speed of the electric oil pump is controlled so as to be supplied to the power transmission mechanism.

  Due to this specific matter, the total amount of the oil supply amount currently supplied from the mechanical oil pump to the power transmission mechanism and the oil supply amount from the electric oil pump to the power transmission mechanism controlled by the electric oil pump control means Is obtained as an amount substantially equal to the required oil supply amount currently required for the power transmission mechanism. In other words, the electric oil pump is controlled so that oil can be supplied to the power transmission mechanism without excess or deficiency, and the situation where excessive oil supply operation is continuously maintained in the power transmission mechanism is avoided. Can do. For this reason, useless energy loss (electric energy loss) in the electric oil pump is eliminated, and excess oil in the power transmission mechanism greatly increases the stirring resistance of various rotating bodies (gears, motor rotors, etc.). It is possible to avoid such a situation that the output torque output to the drive wheels is reduced.

  Moreover, the following is mentioned as a specific structure of the said required supply amount recognition means. In other words, the required oil supply amount is obtained by adding the corrected oil amount, which increases as the temperature of the oil supplied to the power transmission mechanism increases, to the required reference oil supply amount that is determined according to the running state of the vehicle. The necessary supply amount recognition means is configured to calculate.

  If the oil temperature is high, the viscosity of the oil will be low, and the amount of leakage in the hydraulic path leading to the power transmission mechanism or inside the power transmission mechanism may increase. It is necessary to increase the required oil supply. Therefore, by calculating the amount increased by the amount of leakage as the required oil supply amount, the oil supply amount supplied from the mechanical oil pump to the power transmission mechanism and the power transmission mechanism from the electric oil pump It is possible to obtain the total amount of the oil supply amount supplied to the engine with high accuracy as an amount substantially corresponding to the required oil supply amount required for the power transmission mechanism.

  Moreover, the following is mentioned as a specific structure of the said oil supply amount detection means. In other words, by subtracting the correction oil amount, which becomes larger as the oil discharge temperature is higher and the oil discharge pressure is higher, from the oil discharge amount of the mechanical oil pump obtained based on the rotational speed of the internal combustion engine. The oil supply amount detection means is configured to calculate the amount of oil supplied from the mechanical oil pump to the power transmission mechanism.

  The higher the oil discharge temperature and the higher the oil discharge pressure, the greater the amount of leakage along the hydraulic path from the mechanical oil pump to the power transmission mechanism. The amount of oil supplied to the power transmission mechanism is reduced by this amount of leakage. For this reason, the amount reduced by this amount of leakage is calculated as the amount of oil that has reached the power transmission mechanism from the mechanical oil pump, so that the amount of oil that has reached this power transmission mechanism can be accurately recognized. Is possible.

  Further, the specific configuration of the electric oil pump control means includes the following. In other words, the amount of oil obtained by adding the corrected oil amount that becomes larger as the oil discharge temperature is higher and the oil discharge pressure is higher to the supply oil shortage amount calculated by the supply oil shortage amount calculation means. The electric oil pump control means is configured to control the rotational speed of the electric oil pump so that is discharged from the electric oil pump.

  The higher the oil discharge temperature from the electric oil pump and the higher the oil discharge pressure, the greater the amount of leakage in the hydraulic path from the electric oil pump to the power transmission mechanism. In order to supply the amount of oil corresponding to the shortage amount of supplied oil to the power transmission mechanism, it is necessary to increase the discharge amount from the electric oil pump by this amount of leakage. By controlling the electric oil pump in consideration of the leakage amount in this way, the oil supply amount supplied from the mechanical oil pump to the power transmission mechanism and the oil supply supplied from the electric oil pump to the power transmission mechanism The total amount with the amount can be obtained with high accuracy as an amount that substantially matches the required oil supply amount currently required for the power transmission mechanism.

  Moreover, the following are also mentioned as another solution means for achieving said objective. First, an oil pump unit is constituted by a mechanical oil pump driven by an internal combustion engine and an electric oil pump driven by an electric motor, and the above oil pump is used for a power transmission mechanism for transmitting a driving force to driving wheels. Assume a drive control device for an oil pump unit that supplies oil from the unit. The oil supply amount supplied to the power transmission mechanism from the mechanical oil pump in the driving state of the internal combustion engine is subtracted from the required oil supply amount required for the power transmission mechanism to the drive control device of the oil pump unit. The number of rotations of the electric oil pump is obtained from an oil amount map using the supplied oil shortage amount and the oil temperature as parameters, and the electric oil pump is controlled at this rotation number.

  Further, an oil pump unit is constituted by a mechanical oil pump driven by an internal combustion engine and an electric oil pump driven by an electric motor, and the oil pump described above with respect to a power transmission mechanism for transmitting driving force to driving wheels Assume a drive control device for an oil pump unit that supplies oil from the unit. The oil supply amount supplied to the power transmission mechanism from the mechanical oil pump in the driving state of the internal combustion engine is subtracted from the required oil supply amount required for the power transmission mechanism to the drive control device of the oil pump unit. The number of rotations of the electric oil pump is obtained from an oil amount map using the supplied oil shortage and the oil pressure as parameters, and the electric oil pump is controlled by this number of rotations.

  Even according to these specific matters, the total amount of the oil supply amount currently supplied from the mechanical oil pump to the power transmission mechanism and the oil supply amount from the electric oil pump to the power transmission mechanism is now the power transmission mechanism. Therefore, it is obtained as an amount substantially corresponding to the required oil supply amount required for the above. For this reason, useless energy loss (electric energy loss) in the electric oil pump is eliminated, and excess oil in the power transmission mechanism greatly increases the stirring resistance of various rotating bodies (gears, motor rotors, etc.). It is possible to avoid such a situation that the output torque output to the drive wheels is reduced.

  In these solutions, the relationship between the oil temperature or oil pressure, which is one of the parameters of the oil amount map, and the rotational speed of the electric oil pump obtained from the oil amount map is as follows.

  In other words, as described above, the higher the oil temperature and the higher the oil pressure, the greater the required oil supply amount required for the power transmission mechanism, which is supplied from the mechanical oil pump to the power transmission mechanism. The oil supply amount is small, and the oil amount to be supplied from the electric oil pump toward the power transmission mechanism is a large value. For this reason, the rotational speed of the electric oil pump is set higher by the oil amount map so that the higher the oil temperature and the higher the oil pressure, the larger the oil supply amount from the electric oil pump. become. As a result, an appropriate amount of oil can be discharged from the electric oil pump.

  Note that a hybrid vehicle equipped with any one of the above-described solving means and an oil pump unit drive control device is also within the scope of the technical idea of the present invention. This will be specifically described below. The hybrid vehicle includes a motor that outputs a driving force for traveling, and a gear shift operation that is provided in a power transmission path between the motor and the drive wheels and that changes the engagement state of the friction engagement elements. Machine. The required oil supply amount required for the power transmission mechanism is set to increase as the output torque of the motor increases.

  The greater the output torque of the motor, that is, the greater the torque input to the transmission, the greater the torque capacity required for the friction engagement element of the transmission. In order to obtain a large torque capacity, a large amount of oil is required to be supplied to the power transmission mechanism. For this reason, in the present solution, as the output torque of the electric motor is larger, the required oil supply amount required for the power transmission mechanism is set to be larger so that the required oil supply amount can be increased. The gear shifting operation can be smoothly performed by obtaining an appropriate torque capacity for the combination element.

  In the present invention, the shortage of the supplied oil is calculated by subtracting the amount of oil supplied to the power transmission mechanism from the mechanical oil pump from the amount of oil currently required for the power transmission mechanism. The electric oil pump is controlled so as to compensate only for the minute. As a result, oil can be supplied to the power transmission mechanism without excess or deficiency, useless energy loss in the electric oil pump can be eliminated, and excessive supply of oil to the power transmission mechanism can be avoided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a case where the present invention is applied to a hybrid vehicle including two motors / generators and configured as an FR (front engine / rear drive) vehicle will be described.

-Overall configuration of hybrid system-
FIG. 1 is a diagram showing a schematic configuration of a hybrid system mounted on a hybrid vehicle according to the present embodiment. FIG. 2 is a diagram schematically showing a gear train (power transmission mechanism 10 described later) of the hybrid system. The vehicle HV shown in FIG. 1 is an F / R hybrid vehicle (hereinafter simply referred to as “vehicle”). In FIG. 1, the vehicle HV includes an engine (internal combustion engine) 1 as a main driving force source. The engine 1 is a well-known power unit that burns a mixture of fuel and air in a cylinder, converts the thermal energy into rotational kinetic energy, and outputs it.

  Specifically, a gasoline engine, a diesel engine, an LPG engine, or the like is applicable as the engine 1, and the operation state can be controlled by the throttle opening (intake amount), the fuel injection amount, the ignition timing, and the like. Yes. The control is performed by an electronic control unit (E-ECU) 100 mainly composed of a microcomputer.

  The crankshaft 11 that is the output shaft of the engine 1 is rotatable about the front-rear direction of the vehicle HV as a rotation axis. A flywheel 12 is disposed at the rear end of the crankshaft 11. The input shaft 2 is connected to the flywheel 12 via a damper mechanism 21.

  Further, in the casing 3 housing the hybrid system, in order from the front side of the vehicle HV, a first motor / generator (MG1) 4 that functions mainly as a generator, a power distribution mechanism 5, and a first function that functions mainly as an electric motor. A two-motor generator (MG2 prime mover) 6 and a two-speed reduction mechanism 7 are arranged.

  As each of the motor generators 4 and 6, a synchronous motor having both a power running function for converting electrical energy into kinetic energy and a regeneration function for converting kinetic energy into electrical energy is used. More specifically, the first motor / generator 4 receives the driving force of the engine 1 through the power distribution mechanism 5 to generate electric power for supplying power to the second motor / generator 6, or drive when the vehicle starts. Functions as a force source. On the other hand, the second motor / generator 6 functions to assist the driving force of the vehicle and to generate power by regenerative operation during braking or deceleration. These motor generators 4 and 6 have stators 41 and 61 and rotors 42 and 62, respectively. The stators 41 and 61 are fixed to the inner wall of the casing 3. Each motor / generator 4, 6 is connected via an inverter 81 to a power storage device 8 capable of transferring power. As the power storage device 8, a secondary battery, specifically, a battery (such as a nickel metal hydride battery), a capacitor, or the like can be used. The motor generators 4 and 6 are configured to control power running, regeneration, and torque in each case by controlling an inverter 81 by an electronic control unit (MG-ECU) 101 mainly composed of a microcomputer. Has been.

  The power distribution mechanism 5 is constituted by a single pinion type planetary gear mechanism. That is, the power distribution mechanism 5 holds a sun gear 52 formed on the hollow shaft 51, a ring gear 53 disposed concentrically with the sun gear 52, and a plurality of pinion gears 54 that mesh with the sun gear 52 and the ring gear 53. And a carrier 55. The input shaft 2 and the carrier 55 are coupled together in a rotating manner. The input shaft 2 is disposed in the hollow shaft 51, and the input shaft 2 and the hollow shaft 51 can be rotated relative to each other.

  The crankshaft 11, flywheel 12, input shaft 2, and power distribution mechanism 5 are arranged on the same axis. The first motor / generator 4 is disposed between the flywheel 12 and the damper mechanism 21 and the power distribution mechanism 5 in the longitudinal direction of the vehicle HV (the axial direction of the crankshaft 11). The input shaft 2 is arranged so as to pass through the internal space of the rotor 42 of the generator 4. As described above, since the carrier 55 is connected to the rear end of the input shaft 2, the carrier 55 is an input element in the power distribution mechanism 5. Further, since the rotor 42 of the first motor / generator 4 is connected to the sun gear 52 through the hollow shaft 51 so as to rotate together, the sun gear 52 is a so-called reaction force element. Further, the ring gear 53 is integrally connected to an output shaft (drive shaft) 9 described later.

  The reduction mechanism 7 is constituted by a Ravigneaux planetary gear mechanism. That is, the reduction mechanism 7 holds the front sun gear 71, the rear sun gear 72 having a larger diameter than the front sun gear 71, the long pinion gear 73, the short pinion gear 74, the ring gear 75, and the long pinion gear 73 and the short pinion gear 74 in a rotatable manner. The carrier 76 is provided.

  The front sun gear 71 is connected to a first brake (friction engagement element) B1 that permits or restricts its rotation. As this first brake B1, a hydraulically controlled friction engagement device is used.

  The rear sun gear 72 is rotatably connected to the rotor 62 of the second motor / generator 6 by a hollow shaft 77.

  Long pinion gear 73 meshes with front sun gear 71 via short pinion gear 74. That is, the short pinion gear 74 meshes with the long pinion gear 73 and the front sun gear 71, respectively. The long pinion gear 73 meshes with the rear sun gear 72 and the ring gear 75, respectively.

  The ring gear 75 is connected to a second brake (friction engagement element) B2 that permits or restricts the rotation of the ring gear 75 while the inner peripheral side meshes with the long pinion gear 73. A hydraulically controlled friction engagement device is also used as the second brake B2.

  An output shaft 9 is connected to the carrier 76 in an integrated manner. The output shaft 9 is arranged coaxially with the input shaft 2. The front end of the output shaft 9 is connected to the ring gear 53 of the power distribution mechanism 5 so as to rotate together. The hollow shaft 77 is disposed outside the output shaft 9, and the output shaft 9 and the hollow shaft 77 can rotate relative to each other. The hollow shaft 77 and the rotor 62 of the second motor / generator 6 are coupled together in a rotating manner.

  Therefore, in the reduction mechanism 7, the rear sun gear 72 is a so-called input element, and the carrier 76 is an output element. Further, by engaging the first brake B1, a high speed stage having a speed ratio larger than “1” is set, and by engaging the second brake B2 instead of the first brake B1, the speed ratio is changed from the high speed stage. A large low speed stage is set. The speed change between the respective speeds is executed based on a traveling state such as a vehicle speed and a required driving force (or accelerator opening). More specifically, the shift speed region is determined in advance as a map (shift diagram), and control is performed so as to set one of the shift speeds according to the detected driving state. An electronic control unit (T-ECU) 102 mainly including a microcomputer for performing the control is provided.

  On the other hand, the output shaft 9 and the differential 91 are connected by a propeller shaft (not shown). The differential 91 is connected to drive shafts 92 and 92 via a differential mechanism (not shown) housed therein, and wheels (drive wheels) T and T are attached to the drive shafts 92 and 92.

  Hereinafter, operations of the mechanisms 5 and 7 will be described.

  When the reaction force torque from the first motor / generator 4 is input to the sun gear 52 with respect to the output torque of the engine 1 input to the carrier 55 as the operation of the power distribution mechanism 5, the ring gear 53 serving as an output element A torque larger than the torque input from the engine 1 is obtained as an output. In this case, the first motor / generator 4 functions as a generator. Further, when the rotation speed (output rotation speed) of the ring gear 53 is constant, the rotation speed of the engine 1 is continuously (steplessly) changed by increasing / decreasing the rotation speed of the first motor / generator 4. be able to. That is, the control for setting the rotation speed of the engine 1 to, for example, the rotation speed with the best fuel consumption can be performed by controlling the first motor / generator 4.

  Further, as the operation of the reduction mechanism 7, when the first brake B1 is released and the second brake B2 is engaged, the ring gear 75 is fixed by the second brake B2. Thus, the low speed stage L is set, and the torque output from the second motor / generator 6 is amplified according to the gear ratio and added to the output shaft 9. On the other hand, when the first brake B1 is engaged and the second brake B2 is released, the front sun gear 71 is fixed by the first brake B1. Thereby, the high speed stage H having a smaller gear ratio than the low speed stage L is set. Since the gear ratio at the high speed stage H is larger than “1”, the torque output from the second motor / generator 6 is amplified according to the gear ratio and added to the output shaft 9.

  In the state where the gears L and H are constantly set, the torque applied to the output shaft 9 is a torque obtained by increasing the output torque of the second motor / generator 6 in accordance with the gear ratio. However, in the shift transition state, the torque is influenced by the torque capacity at each brake B1, B2 and the inertia torque accompanying the change in the rotational speed. The torque applied to the output shaft 9 is a positive torque when the second motor / generator 6 is driven and a negative torque when the second motor / generator 6 is driven.

  The hybrid system described above has the main purpose of operating the engine 1 as efficiently as possible to reduce the amount of exhaust gas and at the same time improve the fuel efficiency, and also to improve the fuel efficiency in this respect by regenerating energy. It is said. Accordingly, when a large driving force is required, the second motor / generator 6 is driven and the torque is applied to the output shaft 9 while the torque of the engine 1 is transmitted to the output shaft 9. In that case, in the low vehicle speed state, the reduction mechanism 7 is set to the low speed stage L to increase the torque to be applied. Thereafter, when the vehicle speed increases, the reduction mechanism 7 is set to the high speed stage H, 2 Reduce the rotational speed of the motor generator 6. This is to prevent the deterioration of fuel consumption by maintaining the driving efficiency of the second motor / generator 6 in a good state.

  Therefore, in this hybrid system, there is a case where the speed change operation by the reduction mechanism 7 is executed during traveling while the second motor / generator 6 is operated. The speed change operation is executed by switching the engagement / release states of the brakes B1 and B2 described above. For example, when switching from the low speed stage L to the high speed stage H, the second brake B2 is released from the engaged state, and the first brake B1 is simultaneously engaged. When switching from the high speed stage H to the low speed stage L, the first brake B1 is released from the engaged state, and the second brake B2 is simultaneously engaged.

-Mode switching-
Specific modes of the hybrid system according to the present embodiment include an engine travel mode, an electric vehicle (EV) mode, and a hybrid mode, and these modes can be switched.

  When the engine running mode is selected, fuel is supplied to the engine 1, and the engine 1 autonomously rotates, while power supply to the second motor / generator 6 is stopped. When the engine 1 is rotating autonomously, the engine torque is transmitted to the output shaft 9 via the input shaft 2, the carrier 55, and the ring gear 53. The torque of the output shaft 9 is transmitted to the wheels T and T via the propeller shaft, the differential 91 and the drive shafts 92 and 92, and a driving force is generated.

  On the other hand, when the electric vehicle mode is selected, the second motor / generator 6 is activated as an electric motor, and the torque of the second motor / generator 6 passes through the reduction mechanism 7 to be output to the output shaft 9, the differential 91, While being transmitted to the wheels T and T via the drive shafts 92 and 92, no fuel is supplied to the engine 1.

  When the hybrid mode is selected, the engine 1 rotates autonomously and power is supplied to the second motor / generator 6, and the torque of the engine 1 and the torque of the second motor / generator 6 are both set to the wheels T, Transmitted to T.

  Thus, the vehicle HV can mechanically distribute the engine torque to the wheels T and T and the first motor / generator 4 via the power distribution mechanism 5, and also the engine 1 or the second motor / generator 6. This is a mechanically distributed hybrid vehicle in which at least one of them can be used as a driving force source. Further, when the engine torque is transmitted to the power distribution mechanism 5, a part of the engine torque is transmitted to the first motor / generator 4 and a differential function among the sun gear 52, the carrier 55 and the ring gear 53 of the power distribution mechanism 5. Thus, the first motor / generator 4 functions as a reaction force element. Therefore, by controlling the rotational speed of the first motor / generator 4 as described above, the engine speed can be controlled steplessly (continuously). That is, the power distribution mechanism 5 also has a function as a continuously variable transmission.

  When the electric vehicle mode or the hybrid mode is selected, in order to control the reduction mechanism 7, two types of transmission modes can be selected as described above, and the transmission ratio of the reduction mechanism 7 can be selected based on the transmission mode. Is controlled. The speed change mode is determined based on the vehicle speed, the required driving force, and the like, and either the low speed mode or the high speed mode can be selected. The required driving force is determined based on a signal from an accelerator opening sensor, for example. For example, when the vehicle speed is equal to or lower than a predetermined vehicle speed and the accelerator opening is equal to or higher than a predetermined value, the low speed mode is selected. On the other hand, when the vehicle speed exceeds the predetermined vehicle speed and the accelerator opening is less than the predetermined value, the high speed mode is selected.

  When the low speed mode is selected, the first brake B1 is released and the second brake B2 is engaged. When the low speed mode is selected and the torque of the second motor / generator 6 is transmitted to the rear sun gear 72, the ring gear 75 becomes a reaction force element, and the torque of the rear sun gear 72 causes the carrier 76, the output shaft 9, and the differential 91 to Via the wheel T, T is transmitted. Here, the rotational speed of the output shaft 9 is lower than the rotational speed of the second motor / generator 6. When the low mode is selected, the speed change ratio of the reduction mechanism 7 is “low (maximum speed change ratio)”.

  On the other hand, when the high speed mode is selected, the second brake B2 is released and the first brake B1 is engaged. Further, the second motor / generator 6 is driven as an electric motor, the front sun gear 71 serves as a reaction force element, and the torque of the rear sun gear 72 is transmitted to the wheels T and T via the carrier 76, the output shaft 9, and the differential 91. . The rotational speed of the output shaft 9 is lower than the rotational speed of the second motor / generator 6. The speed ratio of the reduction mechanism 7 when the high speed mode is selected is “high (small speed ratio)”, which is smaller than the speed ratio of the reduction mechanism 7 set when the low speed mode is selected.

  Further, when the vehicle HV travels by repulsion, the kinetic energy of the vehicle HV is transmitted from the wheels T and T to the second motor / generator 6 and the electric power generated by the second motor / generator 6 is stored in the power storage device 8. Can be charged.

  By the way, when the supply of fuel to the engine 1 is stopped and the conditions for starting (cranking) the engine 1 are satisfied, the first motor / generator 4 is supplied with electric power, and the first motor is supplied. The generator 4 is driven as an electric motor, and the torque of the first motor / generator 4 is transmitted to the engine 1 via the power distribution mechanism 5 and the input shaft 2 to increase the engine speed and supply fuel. Then, the combustion is performed, and the cranking by the first motor / generator 4 is terminated when the engine speed reaches a speed at which the engine can rotate autonomously.

  When the vehicle is reverse (reverse), the second motor / generator 6 rotates in reverse to obtain driving force.

  The torque control of the second motor / generator 6 and the engagement / release timing control of the brakes B1, B2 as described above are executed by feedback control based on the rotation speed of the second motor / generator 6. For example, the current rotational speed of the second motor / generator 6 is compared with the appropriate rotational speed (target rotational speed) of the second motor / generator 6 after the shift determined based on the rotational speed of the output shaft 9 or the like. The feedback control of the supply current to the second motor / generator 6 is performed so that the rotational speed after the shift matches the target rotational speed. Also, feedback control of these engagement / release timings is performed so that the engagement / release operation of each brake B1, B2 is performed at the timing when the rotation speed of the second motor / generator 6 is synchronized with the rotation speed of the output shaft 9. Done.

-Hydraulic control device-
The hybrid vehicle according to the present embodiment is provided with a hydraulic control device 200 for supplying and discharging hydraulic pressure to the brakes B1 and B2 and controlling engagement / release. As shown in FIG. 3, the hydraulic control apparatus 200 adjusts the hydraulic pressure generated by the pump unit PU including the mechanical oil pump MOP and the electric oil pump EOP and the oil pumps MOP and EOP to the line pressure. And a hydraulic circuit 201 that supplies and discharges the hydraulic pressure adjusted with the line pressure as the original pressure to the brakes B1 and B2 and supplies oil for lubrication and cooling to appropriate locations. .

  The mechanical oil pump MOP is a pump that is driven by the engine 1 to generate hydraulic pressure. For example, the mechanical oil pump MOP is coaxially arranged on the output side of the damper mechanism 21 and receives torque from the engine 1 to operate. ing.

  On the other hand, the electric oil pump EOP is a pump driven by a motor (electric motor) (not shown), and is attached to an appropriate location such as the outside of a casing (not shown), such as a battery 204 (auxiliary battery). It operates by receiving electric power from the power storage device and generates hydraulic pressure. The electric oil pump EOP is not limited to being driven by a dedicated motor, but may be driven by any one of the motor generators 4 and 6 described above.

  The hydraulic circuit 201 includes a plurality of solenoid valves, switching valves, or pressure regulating valves, and is configured to be able to electrically control pressure regulation and hydraulic pressure supply / discharge. Since the circuit configuration of the hydraulic circuit 201 is conventionally known, a description thereof is omitted here.

  On the discharge side of each oil pump MOP, EOP, check valves 202, 203 are provided that are opened when the discharge pressure of each oil pump MOP, EOP exceeds a predetermined pressure. The oil pumps MOP and EOP are connected in parallel to the hydraulic circuit 201. In addition, a valve (not shown) that regulates the line pressure increases the discharge amount to increase the line pressure, and conversely controls the line pressure to reduce the discharge amount to lower the line pressure. Is configured to do.

-Electric oil pump control system-
Next, a schematic configuration of a control system for controlling driving of the electric oil pump EOP will be described. As shown in FIG. 3, the hydraulic control apparatus 200 is connected to a pump control unit 300 for controlling the driving of the electric oil pump EOP. The pump control unit 300 receives various detection signals, transmits a rotation command signal to the electric oil pump EOP, and controls the rotation speed (oil discharge amount) of the electric oil pump EOP. This will be specifically described below.

  The pump control unit 300 includes a vehicle speed sensor 301 for detecting the traveling speed of the vehicle, an accelerator opening sensor 302 for detecting the opening of the accelerator pedal, and an oil temperature for detecting the temperature of oil discharged from the pump unit PU. A sensor 303, a hydraulic pressure sensor 304 that detects the pressure of the oil discharged from the pump unit PU, an engine speed sensor 305 that detects the engine speed, and the like are connected. A detection signal is received from each of these sensors 301 to 305. It is designed to be entered.

-Control operation of electric oil pump-
Next, the control operation of the electric oil pump EOP, which is a feature of this embodiment, will be described. As a general procedure for the control operation of the electric oil pump EOP, an operation for calculating the required oil supply amount required for the power transmission mechanism 10 from the first motor / generator 4 to the reduction mechanism 7 (the oil required by the required supply amount recognition means) is calculated. Supply amount calculation operation), an operation for calculating the oil supply amount supplied to the power transmission mechanism 10 from the mechanical oil pump MOP (an oil supply amount detection operation by the oil supply amount detection means), and a shortage of supply oil (Determining whether there is a shortage of supply oil by the supply oil shortage calculating means and calculating the supply oil shortage), and controlling the number of revolutions of the electric oil pump EOP according to this supply oil shortage (Operation of controlling the rotational speed of the electric oil pump EOP by the electric oil pump control means) is performed in this order. Hereinafter, a specific procedure of the control operation of the electric oil pump EOP will be described with reference to the flowchart of FIG.

  First, in step ST1, an operation for calculating the required oil supply amount required for the power transmission mechanism 10 is performed. This operation is performed by the output torque of the second motor / generator 6 determined by the vehicle speed detected by the vehicle speed sensor 301, the accelerator opening detected by the accelerator opening sensor 302, and the like (the vehicle speed and the second motor). The output torque of the generator 6 is a parameter for determining the reference required oil supply amount in the present invention), and is performed based on the oil temperature detected by the oil temperature sensor 303 and the like.

  For example, the higher the vehicle speed, the higher the output torque of the second motor / generator 6, and the higher the oil temperature, the greater the required oil supply amount required for the power transmission mechanism 10. For example, as the output torque of the second motor / generator 6 increases, the torque capacity of the brakes B1 and B2 also needs to be increased in order to smoothly perform the speed change operation in the reduction mechanism 7 (in the brakes B1 and B2). As a result, the required oil supply amount increases. Also, the higher the oil temperature, the lower the viscosity of the oil and the greater the amount of leakage from each part. Therefore, the required oil supply amount is set in consideration of this leakage. That is, the required oil supply amount is calculated by adding the correction oil amount corresponding to the oil temperature to the reference required oil supply amount. For example, every time the oil temperature rises by 10 deg, the required oil supply amount is increased by 5%. These values are not limited to this.

  The required oil supply amount is not limited to that obtained by the above-described calculation, but is obtained by storing the required oil supply amount MAP in the pump control unit 300 and referring to the required oil supply amount MAP. You may do it.

  Considering these, after the calculation operation of the required oil supply amount required for the power transmission mechanism 10 is performed, in step ST2, the oil supply amount supplied to the power transmission mechanism 10 from the mechanical oil pump MOP is calculated. A calculation operation is performed. This operation is performed based on the engine speed detected by the engine speed sensor 305, the oil temperature detected by the oil temperature sensor 303, the oil pressure detected by the hydraulic sensor 304, and the like.

  For example, the higher the engine speed, the greater the amount of oil discharged from the mechanical oil pump MOP. Further, the higher the oil temperature and the higher the oil pressure, the greater the amount of leakage from each part, and the amount of oil supplied from the mechanical oil pump MOP to the power transmission mechanism 10 is only this amount of leakage. Less. In other words, the oil supply amount to be calculated in step ST2 needs to be subtracted from this leakage amount, so that the oil temperature and hydraulic pressure are used as parameters to be supplied from the mechanical oil pump MOP to the power transmission mechanism 10. The calculation is performed by correcting the oil supply amount. For example, every time the oil temperature rises by 10 deg, the oil supply amount is reduced by 5%. Further, every time the hydraulic pressure rises by 0.1 MPa, correction is performed to reduce the oil supply amount by 5%. These values are not limited to this.

  The oil supply amount from the mechanical oil pump MOP is not limited to that obtained by the above-described calculation. The oil supply amount MAP is stored in the pump control unit 300, and the oil supply amount MAP is referred to. You may make it ask by doing.

  Using the required oil supply amount calculated in step ST1 and step ST2 and the oil supply amount supplied to the power transmission mechanism 10 from the mechanical oil pump MOP, the operation for calculating the shortage amount of the supplied oil is performed in step ST3. Done. This operation is performed by subtracting the oil supply amount obtained in step ST2 from the required oil supply amount obtained in step ST1.

  After the supply oil shortage is calculated in step ST3, in step ST4, the operation of calculating the rotational speed of the electric oil pump EOP according to the supply oil shortage is performed. This operation is performed based on the oil temperature detected by the oil temperature sensor 303, the oil pressure detected by the oil pressure sensor 304, and the like. For example, the higher the oil temperature and the higher the hydraulic pressure, the greater the amount of leakage from each part. The amount of discharge from the electric oil pump EOP must be increased by this amount. is there. That is, the rotational speed of the electric oil pump EOP calculated in step ST4 is added by an amount (leakage amount) considering the oil temperature and hydraulic pressure to the shortage amount of supply oil obtained in step ST3. The amount of oil discharge is calculated so as to obtain an amount (an amount obtained by adding the correction amount of the supply oil amount). For example, every time the oil temperature rises by 10 deg, the rotational speed is corrected so that the discharge amount from the electric oil pump EOP is increased by 5%. Further, the rotational speed is corrected so that the discharge amount from the electric oil pump EOP is increased by 5% every time the hydraulic pressure increases by 0.1 MPa. These values are not limited to this.

  The rotation speed of the electric oil pump EOP may be obtained by an arithmetic expression, or the electric oil pump rotation speed control MAP is stored in the pump control unit 300, and the electric oil pump rotation speed control MAP is stored. You may make it obtain | require by referring to.

  After the rotational speed of the electric oil pump EOP is obtained in this way, the process proceeds to step ST5, and the rotation command signal is directed to the hydraulic control device 200 so that the electric oil pump EOP is driven to rotate at the obtained rotational speed. Output. Specifically, the pulse wave of the three-phase DC current for driving the electric oil pump EOP is changed, and the electric oil pump EOP is controlled to rotate at the calculated rotation speed.

  As described above, in the present embodiment, the supply oil is obtained by subtracting the oil amount supplied to the power transmission mechanism 10 from the mechanical oil pump MOP from the oil amount currently required for the power transmission mechanism 10. Is calculated, and the electric oil pump EOP is controlled so as to compensate only for this shortage. For this reason, the total amount of the oil supply amount supplied from the mechanical oil pump MOP to the power transmission mechanism 10 and the oil supply amount supplied from the electric oil pump EOP to the power transmission mechanism 10 is currently the power transmission. It can be obtained as an amount substantially corresponding to the required oil supply amount required for the mechanism 10. That is, the electric oil pump EOP is controlled so that oil can be supplied to the power transmission mechanism 10 without excess or deficiency, and an excessive oil supply operation is continuously maintained in the power transmission mechanism 10. It can be avoided. As a result, useless energy loss (electric energy loss) in the electric oil pump EOP is eliminated, and surplus oil in the power transmission mechanism 10 significantly increases the stirring resistance of various rotating bodies (such as gears and motor rotors). It is possible to avoid such a situation that the torque is increased, and to prevent the output torque output to the wheels T and T from being lowered.

(Modification)
Next, a modified example of the present invention will be described. In the above-described embodiment, the required oil supply amount required for the power transmission mechanism 10 is calculated, and the oil supply amount from the mechanical oil pump MOP is subtracted from the oil required supply amount to thereby reduce the supply oil amount. By calculating the shortage amount, the shortage amount of the supplied oil is supplied to the power transmission mechanism 10 from the electric oil pump EOP.

In this modification, instead of this calculation operation, the rotational speed of the electric oil pump EOP is controlled by an oil amount map. Specifically, the oil amount map is for obtaining the required rotational speed of the electric oil pump EOP based on the following two parameters.
(1) Supply oil shortage obtained by subtracting the oil supply amount supplied to the power transmission mechanism 10 from the mechanical oil pump MOP in the driving state of the engine 1 from the required oil supply amount required for the power transmission mechanism 10 The amount (2) oil temperature or oil pressure More specifically, the operation similar to Step ST1 and Step ST2 of FIG. 4 in the above-described embodiment, the required oil supply amount and the mechanical oil pump MOP to the power transmission mechanism 10 By calculating the oil supply amount being supplied, subtracting the latter from this former, the amount of supply oil shortage is obtained, and by applying this supply oil shortage amount and oil temperature or oil pressure to the oil amount map, The required number of rotations of the electric oil pump EOP is obtained.

  As in the case of the above-described embodiment, the higher the oil temperature and the higher the oil pressure, the greater the required oil supply amount required for the power transmission mechanism 10, and the mechanical oil pump. The amount of oil supplied from the MOP to the power transmission mechanism 10 is a small value, and the amount of oil to be supplied from the electric oil pump EOP to the power transmission mechanism 10 is a large value. For this reason, the oil amount map shows that the oil supply amount from the electric oil pump EOP increases as the oil temperature increases and the oil pressure increases, that is, the rotation speed of the electric oil pump EOP increases. It is set to be obtained as a high value.

  In order to obtain the required rotational speed of the electric oil pump EOP thus obtained, for example, the pulse wave of a three-phase DC current for driving the electric oil pump EOP is changed, and the electric oil pump is driven at the required rotational speed. The oil pump EOP is controlled to rotate.

  Also in this example, as in the above-described embodiment, the oil supply amount supplied from the mechanical oil pump MOP to the power transmission mechanism 10 and the oil supply supplied from the electric oil pump EOP to the power transmission mechanism 10 The total amount with the amount can be obtained as an amount substantially matching the required oil supply amount currently required for the power transmission mechanism 10. That is, the electric oil pump EOP is controlled so that oil can be supplied to the power transmission mechanism 10 without excess or deficiency, and an excessive oil supply operation is continuously maintained in the power transmission mechanism 10. It can be avoided. As a result, useless energy loss (electric energy loss) in the electric oil pump EOP is eliminated, and surplus oil in the power transmission mechanism 10 significantly increases the stirring resistance of various rotating bodies (such as gears and motor rotors). It is possible to avoid such a situation that the torque is increased, and to prevent the output torque output to the wheels T and T from being lowered.

(Other embodiments)
In the embodiment and the modification described above, the case where the present invention is applied to a hybrid vehicle including two motor generators 4 and 6 has been described. The present invention is not limited to this, and includes a motor / generator, a hybrid vehicle that assists the driving force of the vehicle by the motor / generator, and three or more motor / generators, at least one of which is a vehicle. It is also possible to apply the present invention to a hybrid vehicle that assists the driving force.

  In addition, the present invention can be applied not only to a hybrid vehicle but also to a vehicle that uses only an engine as a drive source and performs idling stop control. In other words, the present invention can be applied to any vehicle provided with an oil pump unit that uses both a mechanical oil pump MOP and an electric oil pump EOP.

  Further, it is applicable not only to FR (front engine / rear drive) hybrid vehicles but also to FF (front engine / front drive) hybrid vehicles and 4WD (4-wheel drive) hybrid vehicles. Further, the gear train configuration of the hybrid system is not limited to that of the above embodiment.

  Further, if the required oil supply amount required for the power transmission mechanism 10 can be set small, the number of revolutions of the electric oil pump EOP can be set low, which is efficient. For this reason, among the mechanisms (the first motor / generator 4, the power distribution mechanism 5, the second motor / generator 6, the reduction mechanism 7, etc.) constituting the power transmission mechanism 10, for example, lubrication is required depending on the operation mode. For a mechanism that disappears or a mechanism that does not require cooling, a configuration that can stop oil supply is adopted, and by subtracting the unnecessary amount from the required oil supply amount, the required oil supply amount can be set small. Thereby, the rotation speed of the electric oil pump EOP can be set low. Conversely, when a mechanism capable of supplying oil to the power transmission mechanism 10 is added in addition to the pump unit PU described above, the rotational speed of the electric oil pump EOP can be set low.

1 is a diagram illustrating a schematic configuration of a hybrid system mounted on a hybrid vehicle according to an embodiment. It is a figure which shows typically the gear train of a hybrid system. It is a block diagram which shows the control system of a hydraulic control apparatus. It is a flowchart figure which shows the procedure of control operation | movement of an electric oil pump.

Explanation of symbols

1 engine (internal combustion engine)
4 First motor / generator 5 Power distribution mechanism 6 Second motor / generator 7 Reduction mechanism 10 Power transmission mechanism HV Hybrid vehicle MOP Mechanical oil pump EOP Electric oil pump T Wheel (drive wheel)

Claims (7)

An oil pump unit is constituted by a mechanical oil pump driven by an internal combustion engine and an electric oil pump driven by an electric motor. From the oil pump unit to a power transmission mechanism for transmitting a driving force to driving wheels. In the drive control device of the oil pump unit that supplies oil,
A required supply amount recognizing means for obtaining a required oil supply amount required for the power transmission mechanism;
An oil supply amount detection means for detecting an oil supply amount supplied from the mechanical oil pump to the power transmission mechanism when the internal combustion engine is driven;
By subtracting the oil supply amount from the mechanical oil pump detected by the oil supply amount detection means from the required oil supply amount obtained by the required supply amount recognition means, it is determined whether there is a shortage of supply oil. Supply oil shortage calculating means for calculating the supply oil shortage when the supply oil is insufficient;
When it is determined by the supply oil shortage calculation means that the supply oil is short, an oil amount substantially the same as the calculated supply oil shortage is supplied from the electric oil pump to the power transmission mechanism. And an electric oil pump control means for controlling the rotational speed of the electric oil pump. In the oil pump unit drive control device according to claim 1,
The required supply amount recognizing means adds a correction oil amount that becomes larger as the temperature of the oil supplied to the power transmission mechanism is higher to a reference oil required supply amount that is obtained according to the traveling state of the vehicle. A drive control device for an oil pump unit, characterized in that the required oil supply amount is calculated by In the oil pump unit drive control device according to claim 1 or 2,
The oil supply amount detection means is a correction oil whose value is increased as the oil discharge temperature is higher and the oil discharge pressure is higher from the oil discharge amount of the mechanical oil pump obtained based on the rotational speed of the internal combustion engine. A drive control device for an oil pump unit, which is configured to calculate an oil supply amount supplied to a power transmission mechanism from a mechanical oil pump by subtracting the amount. In the drive control device of the oil pump unit according to claim 1, 2, or 3,
The electric oil pump control means adds to the supply oil shortage calculated by the supply oil shortage calculation means a correction oil amount that increases as the oil discharge temperature increases and the oil discharge pressure increases. A drive control device for an oil pump unit, characterized in that the rotational speed of the electric oil pump is controlled so that the amount of oil obtained in this way is discharged from the electric oil pump. An oil pump unit is constituted by a mechanical oil pump driven by an internal combustion engine and an electric oil pump driven by an electric motor. From the oil pump unit to a power transmission mechanism for transmitting a driving force to driving wheels. In the drive control device of the oil pump unit that supplies oil,
A supply oil shortage amount obtained by subtracting an oil supply amount supplied to the power transmission mechanism from a mechanical oil pump in a driving state of the internal combustion engine from a required oil supply amount required for the power transmission mechanism; A drive control device for an oil pump unit, characterized in that a rotational speed of an electric oil pump is obtained from an oil amount map using temperature as a parameter, and the electric oil pump is controlled by this rotational speed. An oil pump unit is constituted by a mechanical oil pump driven by an internal combustion engine and an electric oil pump driven by an electric motor. From the oil pump unit to a power transmission mechanism for transmitting a driving force to driving wheels. In the drive control device of the oil pump unit that supplies oil,
A supply oil shortage amount obtained by subtracting an oil supply amount supplied to the power transmission mechanism from a mechanical oil pump in a driving state of the internal combustion engine from a required oil supply amount required for the power transmission mechanism; A drive control device for an oil pump unit, characterized in that a rotational speed of an electric oil pump is obtained from an oil amount map using pressure as a parameter, and the electric oil pump is controlled by this rotational speed. A hybrid vehicle equipped with the drive control device for an oil pump unit according to any one of claims 1 to 6,
An electric motor that outputs a driving force for traveling, and a transmission that is provided in a power transmission path from the electric motor to the driving wheel and that performs a speed change operation by changing the engagement state of the friction engagement element. And
A hybrid vehicle characterized in that the required oil supply amount required for the power transmission mechanism is set to increase as the output torque of the electric motor increases.

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