Control device of hybrid vehicle

0001The present invention relates to a hybrid vehicle control device configured to transmit power output from an engine and a motor to a drive shaft via a planetary gear mechanism.

0002Patent Document 1 describes inventions relating to a hybrid vehicle using a first motor, a second motor, and an engine as a driving force source. The hybrid vehicle described in Patent Document 1 includes a planetary gear mechanism as a power distribution integrated mechanism in the drive system between the drive force source and the drive shaft. In the planetary gear mechanism, the first motor is connected to the sun gear, the drive shaft and the second motor are connected to the ring gear, and the engine is connected to the carrier. It also has a clutch that stops and fixes the rotation of the carrier and engine output shafts. Then, in the hybrid vehicle described in Patent Document 1, the torque distribution for driving the two motors most efficiently is set in a state where the engine is stopped and the clutch is engaged, and the two motors of the hybrid vehicle are set. It is configured to perform motor driving (EV driving) by output.

0003Patent Document 2 describes an oil supply structure to a planetary gear mechanism used in a power transmission mechanism of a hybrid vehicle. Specifically, there is a configuration example of a so-called scraping lubrication mechanism in which oil that is scraped up by the rotation of a predetermined gear of a power transmission mechanism and collected in a catch tank is flowed down to a lubricated part such as a planetary gear mechanism and supplied. Are listed. Such a scraping lubrication mechanism has conventionally been widely and generally used as a lubrication structure in a vehicle transmission or a power transmission mechanism.

<p num="0004"><patcit num="1"><text>Japanese Unexamined Patent Publication No. 2008-265600</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2012-163146</text></patcit></p>

<p num="0005"> In the hybrid vehicle described in Patent Document 1 above, the torque is output by both the first motor and the second motor in a state where the rotation of the engine and the carrier is stopped and locked by the brake mechanism, thereby achieving high output. The vehicle can be driven by a motor efficiently. That is, as shown in the co-line diagram of [FIG. 9] in Patent Document 1, when the motors are driven by the two motors as described above, the brake mechanism is engaged by engaging the carrier and the engine. The rotation axis is locked and the rotation speed is fixed at 0. By driving the first motor in the direction opposite to the rotation direction of the second motor in that state, high-power motor running can be performed by the outputs of the two motors.</p><p num="0006"> On the other hand, when the rotation of the carrier is locked and the motors are driven by the two motors as described above, the pinion gear of the planetary gear mechanism rotates at high speed. Further, since the output torque of the first motor is input, the load applied to the pinion gear also increases. Then, in this case, since the operation of the engine is stopped, the supply of oil from the mechanical oil pump driven by the power of the engine is also stopped. Therefore, the temperature of the pinion gear rises, and seizure and wear are likely to occur. On the other hand, in the hybrid vehicle described in Patent Document 1, lubrication and cooling when the pinion gear rotates at high speed as described above are not considered. Even if the hybrid vehicle described in Patent Document 1 is provided with, for example, the scraping lubrication mechanism described in Patent Document 2, the case where the pinion gear rotates at high speed as described above by the scraping lubrication mechanism alone. May lack lubrication and cooling capacity. As a result, the durability of the planetary gear mechanism may decrease.</p><p num="0007"> By avoiding motor running due to the outputs of the two motors with the carrier rotation locked and running the motor only with the output of the second motor, it is possible to suppress seizure and wear of the pinion gear as described above. .. However, in that case, the traveling region in which the high-output motor can be driven by the outputs of the two motors is reduced, and as a result, the motor running performance of the hybrid vehicle is deteriorated.</p><p num="0008"> The present invention was conceived by paying attention to the above technical problems, and improves the durability of the planetary gear mechanism that transmits the output torque of the driving force source to the drive shaft side, and also enables high-output motor running. It is an object of the present invention to provide a control device for a hybrid vehicle capable of appropriately securing a possible traveling area and improving motor traveling performance.</p>

<p num="0009"> In order to achieve the above object, the present invention uses an engine and a first motor and a second motor as driving force sources, the first motor is connected to a sun gear, the second motor is connected to a ring gear, and the sun gear is connected. Alternatively, a planetary gear mechanism in which a drive shaft is connected to the ring gear, the engine is connected to the carrier, and a brake mechanism for selectively stopping and fixing the rotation of the carrier is connected, and the planet driven by the engine. A hybrid vehicle equipped with a mechanical oil pump that generates hydraulic pressure to supply oil to the gear mechanism, the HV mode in which the hybrid vehicle is driven by at least the output of the engine and the output of the second motor. Either the first EV mode in which the hybrid vehicle is driven or the second EV mode in which the hybrid vehicle is driven by the outputs of both the first motor and the second motor while the rotation of the carrier is stopped by the brake mechanism. The hybrid vehicle control device configured to set the traveling mode to travel includes a controller for controlling the traveling state of the hybrid vehicle, and the controller estimates the temperature of the pinion gear of the planetary gear mechanism. If it is determined that the possibility of traveling in the second EV mode is determined and the traveling in the second EV mode is impossible, the setting of the second EV mode is prohibited and the estimated temperature of the pinion gear is increased. The HV mode is set when the temperature is higher than the predetermined temperature, and the first EV mode is set when the estimated temperature is equal to or lower than the predetermined temperature.</p><p num="0010"> Further, the present invention includes an oil supply mechanism that is driven by a power other than the engine to supply oil to the planetary gear mechanism, and the controller estimates and estimates the amount of oil supplied by the oil supply mechanism. When the supply amount is equal to or less than a predetermined amount, it may be configured to determine that the traveling in the second EV mode is impossible.</p><p num="0011"> The present invention also includes an oil supply mechanism that is driven by a power other than the engine to supply oil to the planetary gear mechanism, and the oil supply mechanism is driven by a motor other than the driving force source to supply the planetary gear. It is composed of an electric oil pump that generates oil for supplying oil to the mechanism, and the controller determines the possibility of operation of the electric oil pump, and the electric oil pump cannot be normally operated. When it is determined, it can be configured to determine that the traveling in the second EV mode is impossible.</p><p num="0012"> Further, according to the present invention, when the controller prohibits the setting of the second EV mode, the prohibition of the setting of the second EV mode is released when the traveling time in the HV mode exceeds the first predetermined time. It can also be configured to do so.</p><p num="0013"> The present invention includes an oil supply mechanism that is driven by a power other than the engine to supply oil to the planetary gear mechanism, and the oil supply mechanism is driven by a motor other than the driving force source to supply the planetary gear. It is composed of an electric oil pump that generates oil for supplying oil to the mechanism, and when the controller prohibits the setting of the second EV mode, the operating time after which the electric oil pump is operated is the second. 2 It is also possible to cancel the prohibition of the setting of the second EV mode when the predetermined time is exceeded.</p>

<p num="0014"> According to the present invention, the vehicle travels in the second EV mode when traveling in the second EV mode in which both the first motor and the second motor are driven, or when traveling in the second EV mode is requested. If this is not possible, driving in the second EV mode is prohibited. When traveling in the second EV mode, the load applied to the planetary gear mechanism becomes large, and the pinion gear of the planetary gear mechanism rotates at high speed, so that the pinion gear becomes hot and seizure or wear is likely to occur. Therefore, for example, when the temperature of the pinion gear is higher than the threshold temperature, or when the oil for lubricating and cooling the pinion gear cannot be properly supplied, it is determined that the traveling in the second EV mode is impossible. Then, when running in the 2nd EV mode is prohibited, when running in the 2nd EV mode is prohibited, and the estimated temperature of the pinion gear is equal to or lower than the predetermined temperature, the 1st EV mode is set and the vehicle is set. Is run. Therefore, it is possible to continue or start the motor running while avoiding seizure and wear in the planetary gear mechanism as described above. On the other hand, when the estimated temperature of the pinion gear is higher than the predetermined temperature, the HV mode is set and the vehicle is driven. In this case, the HV mode is set even if the required driving force can be satisfied in the first EV mode. Therefore, in this case, the engine is operated, and at least the output of the engine causes the vehicle to run. Therefore, the planetary gear mechanism can be effectively lubricated and cooled by the hydraulic pressure generated by the mechanical oil pump driven by the engine.</p><p num="0015"> Further, according to the present invention, the amount of oil supplied by the oil supply mechanism can be estimated based on, for example, the oil temperature and the vehicle speed. For example, when the oil temperature is low, the viscosity of the oil increases, so that it can be estimated that the fluidity of the oil decreases and the supply amount decreases. Further, for example, when the vehicle speed is low or conversely, when the vehicle speed is high, it can be estimated that the amount of oil supplied decreases. Then, the possibility of running in the second EV mode can be determined based on the estimated oil supply amount. Therefore, the possibility of traveling in the second EV mode can be easily and appropriately determined.</p><p num="0016"> Further, according to the present invention, the possibility of traveling in the second EV mode can be determined based on the possibility of operation of the electric oil pump. The possibility of operating the electric oil pump can be determined based on, for example, the oil temperature. For example, when the oil temperature is low and the viscosity of the oil is high, it can be determined that the power of the electric oil pump is insufficient and the electric oil pump cannot operate normally. Further, for example, even if some kind of failure occurs in the electric oil pump, it can be determined that the electric oil pump cannot normally operate. Therefore, the possibility of traveling in the second EV mode can be easily and appropriately determined.</p><p num="0017"> Further, according to the present invention, by traveling in the HV mode, the planetary gear mechanism can be reliably lubricated and cooled by the oil discharged from the mechanical oil pump. Therefore, if the time required for the mechanical oil pump to reliably supply oil to the planetary gear mechanism is set to the first predetermined time, the second EV mode is waited for the time for the planetary gear mechanism to be reliably lubricated and cooled. The prohibition of the setting of can be lifted. Therefore, the planetary gear mechanism can be reliably protected. Further, by appropriately cooling the planetary gear mechanism, it is possible to extend the traveling time or the traveling distance in the next second EV mode.</p><p num="0018"> According to the present invention, by normally operating the electric oil pump, the planetary gear mechanism can be reliably lubricated and cooled by the oil discharged by the electric oil pump. Therefore, if the time required for the electric oil pump to reliably supply oil to the planetary gear mechanism is set to the second predetermined time, the time required for the planetary gear mechanism to be reliably lubricated and cooled is waited for in the second EV mode. The prohibition of setting can be lifted. Therefore, the planetary gear mechanism can be reliably protected. Further, by appropriately cooling the planetary gear mechanism, it is possible to extend the traveling time or the traveling distance in the next second EV mode.</p>

0019<figref num="1">It is a figure which shows an example of the structure of the hybrid vehicle which the control device of this invention can control.</figref><figref num="2">It is a flowchart for demonstrating an example of the control executed by the control apparatus of this invention.</figref><figref num="3">It is a time chart for explaining the transition of the temperature of a planetary gear mechanism when the control shown in the flowchart of FIG. 2 is executed.</figref><figref num="4">It is a figure which shows another example of the structure of the hybrid vehicle which the control device of this invention can control.</figref><figref num="5">It is a figure which shows another example of the structure of the hybrid vehicle which the control device of this invention can control.</figref>

0020The present invention will be specifically described with reference to the drawings. First, FIG. 1 shows an example of a hybrid vehicle that can be controlled by the present invention. The vehicle Ve shown in FIG. 1 is a hybrid vehicle whose driving force source is an engine (ENG) 1, a first motor (MG1) 2 and a second motor (MG2) 3. The vehicle Ve is configured to divide and transmit the power output by the engine 1 to the first motor 2 side and the drive shaft 5 side by the power dividing device 4. Further, the electric power generated by the first motor 2 is supplied to the second motor 3, and the power output by the second motor 3 can be added to the drive shaft 5.

0021The engine 1 is configured to electrically control its output adjustment, start and stop operations. For example, in the case of a gasoline engine, the throttle opening, the amount of fuel supplied, the execution and stop of ignition, and the ignition timing are electrically controlled.

0022Both the first motor 2 and the second motor 3 are motors having a power generation function (so-called motor generators), and are composed of, for example, a permanent magnet type synchronous motor. Both the first motor 2 and the second motor 3 are connected to a battery (not shown) via an inverter (not shown), and have a rotation speed, torque, a function as a motor, and a generator. It is configured so that the switching of the function as an inverter is electrically controlled.

0023The power splitting device 4 is composed of a planetary gear mechanism PG having a sun gear 6, a ring gear 7, and a carrier 8. In the example shown in FIG. 1, a single pinion type planetary gear mechanism PG is used.

0024The planetary gear mechanism PG is arranged on the same rotation axis as the output shaft 1a of the engine 1. The first motor 2 is connected to the sun gear 6 of the planetary gear mechanism PG. The first motor 2 is arranged adjacent to the planetary gear mechanism PG on the opposite side of the engine 1, and the rotor shaft 2b that rotates integrally with the rotor 2a of the first motor 2 is used as the sun gear 6. It is connected. The ring gear 7 of the internal gear is arranged concentrically with respect to the sun gear 6. The pinion gear 9 that meshes with the sun gear 6 and the ring gear 7 is held by the carrier 8 so that it can rotate and revolve. The input shaft 4a of the power splitting device 4 is connected to the carrier 8, and the output shaft 1a of the engine 1 is connected to the input shaft 4a via the one-way clutch 10.

0025The one-way clutch 10 includes a rotating member and a fixing member, the rotating member freely rotates in one rotation direction (in this case, the same rotation direction as engine 1), and the rotating member rotates in the other rotation direction (in this case, the engine). It is a clutch mechanism in which the rotating member and the fixing member are engaged when trying to rotate in the direction opposite to 1). The fixing member is fixed to a housing or the like so that it cannot rotate. The rotating member is connected to the output shaft 1a and the carrier 8. Therefore, the one-way clutch 10 is configured to engage and stop the rotation when the output shaft 1a or the carrier 8 tries to rotate in the direction opposite to the rotation direction of the engine 1. By using such a one-way clutch 10, the rotation of the output shaft 1a and the carrier 8 can be stopped according to the direction of torque action. As will be described later, this one-way clutch 10 functions as a brake mechanism that stops the rotation of the output shaft 1a of the engine 1 when the vehicle Ve is driven by the output torques of both the first motor 2 and the second motor 3. It is a thing. Therefore, instead of the one-way clutch 10, for example, a friction brake configured to selectively stop the rotation of the output shaft 1a by controlling the engaging state can be used.

0026The drive gear 11 of the external gear is integrally formed on the outer peripheral portion of the ring gear 7 of the planetary gear mechanism PG. Further, the counter shaft 12 is arranged in parallel with the rotation axis of the planetary gear mechanism PG and the first motor 2. A counter-driven gear 13 that meshes with the drive gear 11 is attached to one end of the counter shaft 12 (on the right side in FIG. 1) so as to rotate integrally. At the other end of the counter shaft 12 (on the left side in FIG. 1), a counter drive gear 16 that meshes with the ring gear 15 of the differential gear 14 which is the final reducer is attached so as to rotate integrally with the counter shaft 12. Has been done. Therefore, the ring gear 7 of the planetary gear mechanism PG is connected to the drive shaft 5 via the gear train including the drive gear 11, the counter shaft 12, the counter driven gear 13, and the counter drive gear 16 and the differential gear 14. ing.

0027The torque output from the second motor 3 can be added to the torque transmitted from the planetary gear mechanism PG to the drive shaft 5. That is, the second motor 3 is arranged in parallel with the counter shaft 12, and the reduction gear 17 connected to the rotor shaft 3b, which rotates integrally with the rotor 3a, meshes with the counter driven gear 13. There is. Therefore, the drive shaft 5 and the second motor 3 are connected to the ring gear 7 of the planetary gear mechanism PG via the gear train or the reduction gear 17 as described above.

0028As described above, in this vehicle Ve, the output shaft 1a of the engine 1 and the rotor shaft 2b of the first motor 2 are connected to the gear train on the drive shaft 5 side and the differential gear 14 via the planetary gear mechanism PG. That is, the output torques of the engine 1 and the first motor 2 are configured to be transmitted to the drive shaft 5 side via the power dividing device 4 configured by the planetary gear mechanism PG.

0029Further, the vehicle Ve is provided with an oil pump 18 for lubrication and cooling of the planetary gear mechanism PG. The oil pump 18 (hereinafter referred to as MOP18) is a mechanical oil pump having a general configuration, which has been conventionally used for a vehicle engine or a transmission as a pump for oil supply and hydraulic control. This MOP18 is configured to generate flood control driven by the torque output by the engine 1. Specifically, the rotor of the MOP 18 (not shown) is configured to rotate with the output shaft 1a of the engine 1. Therefore, when the engine 1 is burned and outputs torque from the output shaft 1a, the MOP 18 is also driven to generate flood control.

0030The oil discharged from the MOP18 by generating the oil pressure of the MOP18 is configured to be supplied to the planetary gear mechanism PG via the oil passage 19. Further, the planetary gear mechanism PG is configured so that oil is also supplied by the scraping lubrication mechanism 20 by the ring gear 15 of the differential gear 14.

0031The scraping lubrication mechanism 20 has a configuration generally used in a vehicle as a lubrication mechanism for a portion using a gear. For example, the scraping lubrication mechanism 20 is provided so that the tooth tip portion of the ring gear 15 is immersed in oil such as an oil pan (not shown). Then, when the ring gear 15 rotates by the torque transmitted from the drive shaft 5 side, the oil scraped up from the oil pan is supplied to the planetary gear mechanism PG. Therefore, even when the rotation of the output shaft 1a of the engine 1 is stopped, oil is supplied to the planetary gear mechanism PG when the vehicle Ve is running and the drive shaft 5 is rotating. be able to.

0032As described above, the MOP18 cannot generate flood control when the rotation of the output shaft 1a of the engine 1 is stopped. When the vehicle Ve is running, oil can be supplied to the planetary gear mechanism PG by the scraping lubrication mechanism 20. However, since the scraping lubrication mechanism 20 has a configuration in which the oil once scraped upward by the ring gear 15 is supplied to the planetary gear mechanism PG by the action of gravity, the lubrication of the forced lubrication method in which the oil is pumped by flood control. Low lubrication and cooling performance compared to the mechanism. Further, the lubrication / cooling performance of the scraping lubrication mechanism 20 changes depending on the oil temperature and the vehicle speed. For example, when the oil temperature is low, the viscosity of the oil increases and the fluidity decreases. Therefore, when the oil temperature is low, the amount of oil supplied by the scraping lubrication mechanism 20 is small. Further, when the vehicle speed is low, the rotation speed of the ring gear 15 is low, and the amount of oil scooped up by the ring gear 15 is inevitably reduced. Further, when the oil temperature is high and the viscosity of the oil is low, or when the rotation speed of the pinion gear 9 is high at a high vehicle speed, the oil supplied to the pinion gear 9 is blown off without adhering to the pinion gear 9 by centrifugal force. It ends up. Therefore, as a result, the amount of oil supplied to the pinion gear 9 is reduced.

0033Therefore, this vehicle Ve maintains the supply of oil to the planetary gear mechanism PG even when the engine 1 is stopped or the pumping lubrication mechanism 20 lacks lubrication / cooling performance. An oil pump 21 is provided to properly lubricate and cool the planetary gear mechanism PG. In the example shown in FIG. 1, the oil pump 21 (hereinafter referred to as EOP21) is composed of an electric oil pump that is driven by the torque output by the electric motor to generate oil pressure. Therefore, the EOP21 is provided with a pump motor 22 for driving the EOP21. The pump motor 22 is an electric motor different from the driving force source of the vehicle Ve such as the engine 1 and the first motor 2 and the second motor 3, and is provided exclusively for the EOP 21 in the example shown in FIG. ..

0034The oil discharged from the EOP 21 by generating the oil pressure of the EOP 21 is configured to be supplied to the planetary gear mechanism PG via the oil passage 23. As shown in FIG. 1, the oil passage 23 can be configured as an independent oil passage connecting the EOP 21 and the planetary gear mechanism PG, but the oil passage 23 is partially shared with the oil passage 19 described above. It can also be configured as.

0035The vehicle Ve is provided with a vehicle speed sensor 24 that detects the vehicle speed of the vehicle Ve. Based on the vehicle speed detected by the vehicle speed sensor 24, it is possible to estimate the amount of oil supplied to the planetary gear mechanism PG by the above-mentioned scraping lubrication mechanism 20 and the later-described output shaft-driven mechanical oil pump. ..

0036Further, an oil temperature sensor 25 for detecting the temperature of the oil supplied to each oil supply unit by the above MOP 18 and EOP 21 is provided. The oil temperature sensor 25 is configured to detect, for example, the temperature of oil stored in an oil pan (not shown) or the like. Based on the oil temperature detected by the oil temperature sensor 25, the viscosity or fluidity of the oil can be estimated. As a result, the amount of oil supplied to the planetary gear mechanism PG by the above-mentioned scraping lubrication mechanism 20 and EOP21 can be estimated.

0037Further, a rotation speed sensor 26 for detecting the rotation speeds of the first motor 2 and the third motor 3 is provided. Based on the rotation speeds of the first motor 2 and the third motor 3 detected by the rotation speed sensor 26, and the current values supplied to the first motor 2 and the third motor 3, respectively, the first motor 2 and the third motor 3 The output torque of the third motor 3 can be obtained respectively.

0038Then, a controller 27 (hereinafter, ECU 27) for executing the operation control of the engine 1, the rotation control of the first motor 2 and the second motor 3, the rotation control of the pump motor 23, and the like as described above is provided. ing. The ECU 27 is mainly composed of, for example, a microcomputer. The EUC27 is configured to input detection data such as the vehicle speed sensor 24, the oil temperature sensor 25, and the rotation speed sensor 26, for example. Then, a calculation is performed using the input data, data stored in advance, and the like, and a control command signal is output based on the calculation result.

0039The vehicle Ve configured as described above is controlled so as to improve energy efficiency or fuel efficiency by effectively utilizing the engine 1 and the first motor 2 and the second motor 3 as driving force sources. Specifically, by at least the "HV mode" in which the vehicle Ve is driven by the output of the engine 1 and the output of at least one of the motor generators of the first motor 2 and the second motor 3 by stopping the operation of the engine 1. The "EV mode" for driving the vehicle Ve is appropriately selected according to the traveling state of the vehicle Ve.

0040Of the above driving modes, the "EV mode" is particularly the "first EV mode" in which the vehicle Ve is driven by the output of the second motor 3 and the motor generators of both the first motor 2 and the second motor 3. Depending on the output, it is classified into the "second EV mode" in which the vehicle Ve is driven at high output. These "first EV mode" and "second EV mode" are appropriately selected according to the traveling state of the vehicle Ve.

0041In the "first EV mode", the second motor 3 is controlled to rotate as a motor in the positive direction (rotational direction of the output shaft 1a of the engine 1) and output torque. Then, the vehicle Ve is driven by the driving force generated by the output torque of the second motor 3.

0042In the "second EV mode", the vehicle Ve is driven by the outputs of both the first motor 2 and the second motor 3. In this "second EV mode", the first motor 2 is controlled to rotate as a motor in the reverse rotation direction (the rotation direction opposite to the rotation direction of the output shaft 1a of the engine 1) and output torque. Further, the second motor 3 is controlled to rotate as a motor in the forward rotation direction (the same rotation direction as the rotation direction of the output shaft 1a of the engine 1) and output torque. Then, the vehicle Ve is driven by the driving force generated by the output torque of the first motor 2 and the output torque of the second motor 3. In this case, since the carrier 8 and the input shaft 4a try to rotate in the reverse rotation direction, the one-way clutch 10 is engaged. Therefore, the vehicle Ve can be efficiently driven by the output torques of both the first motor 2 and the second motor 3 in a state where the rotation of the output shaft 1a of the carrier and the engine 1 is stopped and fixed.

0043As described above, in this vehicle Ve, the "HV mode" and the "EV mode" can be appropriately switched according to the driving condition, the required driving force, and the like. As described above, in the "EV mode", the operation of the engine 1 is stopped, so that the MOP18 cannot generate the flood control. Of the "EV modes", when the "first EV mode" is set, oil is required especially for lubrication and cooling of the second motor 3. When the "second EV mode" is set, in addition to cooling the first motor 2 and the second motor 3, in particular, the pinion gear 9 of the planetary gear mechanism PG and the pinion shaft supporting the pinion gear 9 are supported. Oil is needed for lubrication and cooling of 9a. In this case, as described above, the first motor 2 and the second motor 3 rotate in opposite rotation directions in a state where the one-way clutch 10 is engaged and the rotation of the output shaft 1a and the carrier 8 is stopped. Be forced to. That is, in the planetary gear mechanism PG, the sun gear 6 and the ring gear 7 rotate in opposite rotation directions while the rotation of the carrier 8 is stopped. Therefore, the pinion gear 9 supported by the carrier 8 rotates on its axis with the revolution around the sun gear 6 stopped. The rotation speed of rotation in this case is determined by the difference rotation speed between the sun gear 6 and the ring gear 7, but since the sun gear 6 and the ring gear 7 rotate in opposite directions, the pinion gear 9 rotates at high speed. .. Therefore, especially when the "second EV mode" is set, in order to prevent seizure and excessive wear of the pinion gear 9 and the pinion shaft 9a that rotate at high speed as described above, the planetary gear mechanism PG is used. It is necessary to supply a sufficient amount of oil.

0044In addition, the vehicle Ve can charge the battery for driving by the electric power supplied from the external power source, and the PHV (Plug in Hybrid) equipped with the battery having a relatively large capacity is installed. In the case of Vehicle), the frequency of motor running in the "1st EV mode" is higher than that of a normal HV (Hybrid Vehicle). In the "first EV mode", the rotation speed of the pinion gear 9 does not increase as in the case where the "second EV mode" as described above is set. Even so, when the continuous operation time in the "first EV mode" becomes long, the temperature of the second motor 3 rises, and the temperature also rises in the planetary gear mechanism PG and the rotating part of the gear train. Therefore, in order to lubricate and cool the second motor 3 and the rotating parts, it may be necessary to drive the EOP 21 as in the case where the "second EV mode" is set.

0045Therefore, in this vehicle Ve, the EOP 21 is driven when the "EV mode" is set or when the engine 1 is stopped. That is, it is configured to control the pump motor 22 to generate oil pressure by the EOP21 and supply oil to the planetary gear mechanism PG.

0046As described above, the vehicle Ve is in a state in which the pinion gear 9 of the planetary gear mechanism PG rotates at high speed, especially when the vehicle is driven by the motor in the "second EV mode". In that case, if the oil supplied to the planetary gear mechanism PG is insufficient, seizure or excessive wear may occur in the pinion gear 9. Therefore, the controller 27 of this vehicle Ve is described below in order to prevent seizure and wear, improve the durability of the planetary gear mechanism PG, and expand the range in which the motor can run in the "second EV mode". It is configured to execute the control example shown.

0047The control shown in the flowchart of FIG. 2 is executed when the vehicle Ve is required to run the motor in the "second EV mode", or when the vehicle Ve is already running the motor in the "second EV mode". Will be done. Hereinafter, in the description of this flowchart, the motor running in the "second EV mode" will be referred to as "both drive", and the motor running in the "first EV mode" will be referred to as "single drive".

0048First, it is determined whether or not the motor can run with both drives (step S1). That is, the possibility of running in the "second EV mode" is determined. This determination can be performed, for example, based on the oil temperature of the oil supplied to the planetary gear mechanism PG or the estimated temperature of the planetary gear mechanism PG. For example, if the oil temperature or the estimated temperature of the planetary gear mechanism PG is higher than the preset upper limit temperature, it is determined that seizure may occur in the planetary gear mechanism PG. Therefore, in that case, it is determined that both drives are impossible.

0049Further, the determination of the possibility of running in the above-mentioned "second EV mode" can be executed based on the estimated value of the amount of oil supplied to the planetary gear mechanism PG. The amount of oil supplied to the planetary gear mechanism PG can be estimated based on the detection data of the oil temperature sensor 25. When the oil temperature is low, the viscosity of the oil is high and the fluidity is low. Therefore, for example, when the oil temperature is lower than the preset predetermined oil temperature, it can be determined that the amount of oil supplied to the planetary gear mechanism PG is equal to or less than the preset predetermined amount. Then, in that case, it can be determined that both drives are impossible because the oil is insufficient.

0050It is also possible to estimate the amount of oil supplied to the planetary gear mechanism PG based on the detection data of the vehicle speed sensor 24 and the oil temperature sensor 25. As described above, the amount of oil supplied by the scraping lubrication mechanism 20 decreases at low vehicle speeds and high vehicle speeds. Therefore, for example, when the vehicle speed is outside the preset predetermined vehicle speed range, it can be determined that the amount of oil supplied to the planetary gear mechanism PG is equal to or less than the preset predetermined amount. In that case, it can be determined that both drives are impossible because the oil is insufficient.

0051Furthermore, the determination of the possibility of motor running in both drives can also be made based on the possibility of operation of the EOP21. That is, when the normal operation of the EOP21 is impossible, it is judged that the motor running with both drives is also impossible. The possibility of operation of the EOP21 can be determined based on, for example, the detection data of the oil temperature sensor 25. As described above, when the oil temperature is low and the viscosity of the oil is high, the power of the EOP21 is insufficient, and it becomes difficult to operate the EOP21 in a normal state. Therefore, for example, when the oil temperature is lower than the preset predetermined oil temperature, it can be determined that the normal operation of the EOP21 is impossible, and accordingly, it can be determined that both drives are impossible.

0052Further, even if some kind of failure occurs in the EOP21, it can be determined that the normal operation of the EOP21 is impossible. Therefore, even when the fail signal from the EOP21 is detected, it can be determined that both drives are impossible.

0053If the motor can run in both drives and a positive judgment is made in step S1, the process proceeds to step S2. In step S2, motor driving with both drives is permitted. For example, both drive prohibition flags are turned off. The dual drive prohibition flag is set to be turned off when the motor traveling with both drives is permitted, and turned ON when the motor traveling with both drives is prohibited. When both drives are permitted in step S2, that is, when the both drives prohibition flag is turned off, this routine is temporarily terminated without executing the subsequent control.

0054On the other hand, if it is negatively determined in step S1 because the motor cannot run in both drives, the process proceeds to step S3. In step S3, motor running with both drives is prohibited. Specifically, both drive prohibition flags as described above are turned ON.

0055Next, in step S4, it is determined whether or not the required driving force is larger than the driving force that can be output in a single drive (maximum driving force in a single drive). The required driving force can be obtained, for example, based on the vehicle speed and the accelerator opening. The driving force that can be output by a single drive is the maximum driving force that can be achieved only by the output of the second motor 3.

0056If the required driving force is larger than the driving force that can be output by a single drive and the determination is positive in step S4, the process proceeds to step S5. In step S5, the traveling mode of the vehicle Ve is set to the "HV mode", and the traveling in the "HV mode" is started. Specifically, the engine 1 is started, and the vehicle Ve is driven by the output of the engine 1 or by the output of the engine 1 and the second motor 3. If the vehicle is already running in the "HV mode", the driving in the "HV mode" is continued.

0057On the other hand, if the required driving force is equal to or less than the driving force that can be output by a single drive and a negative judgment is made in step S4, the process proceeds to step S6. In step S6, it is determined whether or not the estimated temperature of the planetary gear mechanism PG, specifically, the pinion gear 9, the pinion shaft 9a, and the bearing of the planetary gear mechanism PG is higher than the predetermined temperature Tc. ..

0058The estimated temperature of the pinion gear 9, the pinion shaft 9a, the bearing, and the like can be obtained based on, for example, the oil temperature of the oil supplied to the planetary gear mechanism PG and the rotation speed of the pinion gear 9. At that time, the temperature of the pinion gear 9 can be estimated in consideration of the load applied to the planetary gear mechanism PG, specifically, the output torques of the first motor 2 and the second motor 3. Alternatively, the estimated temperature of the pinion gear 9, the pinion shaft 9a, the bearing, and the like can be obtained based on the detection data of the temperature sensor provided in the planetary gear mechanism PG.

0059The predetermined temperature Tc is a temperature lower than the limit temperature at which seizure occurs in the pinion gear 9, but is set in advance as a threshold value for determining that the pinion gear 9 needs to be strongly cooled. When the estimated temperature of the pinion gear 9, the pinion shaft 9a, the bearing, etc. becomes higher than the predetermined temperature Tc, it is determined that it is necessary to supply oil to the planetary gear mechanism PG by the hydraulic pressure generated by the MOP18.

0060Therefore, if the estimated temperature of the pinion gear 9, the pinion shaft 9a, the bearing, etc. is higher than the predetermined temperature Tc and a positive judgment is made in this step S6, the process proceeds to step S5 described above, and the vehicle Ve travels. The mode is set to "HV mode". That is, in this case, even if the required driving force can be satisfied by the single drive motor running, the cooling of the pinion gear 9 is prioritized and the mode is shifted to the "HV mode". If the vehicle is already running in the "HV mode", the driving in the "HV mode" is continued.

0061The "HV mode" is set, and when the vehicle Ve runs in the "HV mode", the MOP18 is driven by the output of the engine 1. Therefore, the pinion gear 9 can be cooled and lubricated by the oil pressure generated by the MOP 18. That is, the pinion gear 9 can be effectively cooled by the MOP 18, which can supply a relatively large amount of oil as compared with the scraping lubrication mechanism 20 and the EOP 21.

0062On the other hand, if the estimated temperature of the pinion gear 9, the pinion shaft 9a, the bearing, etc. is equal to or less than the predetermined temperature Tc, and the negative determination is made in step S6, the process proceeds to step S7. In step S7, the single-drive motor running is started. That is, the traveling mode of the vehicle Ve is set to the "first EV mode", and the traveling in the "first EV mode" is started. Specifically, the vehicle Ve is driven by the output of the second motor 3 alone.

0063After both drives are prohibited as described above and the driving mode of the vehicle Ve is set to the "HV mode" or the "first EV mode", the prohibition of both drives is lifted by satisfying a predetermined condition. If "HV mode" is set in step S5 above, the running time in that "HV mode" is the first fixed time t in the first place._aIt is determined whether it is longer than (step S8). 1st predetermined time t_aIs set to the time required for the pinion gear 9 to be sufficiently cooled after the start of running in the "HV mode". For example, the oil supplied to the pinion gear 9 by the MOP 18 sets the time required for the temperature of the pinion gear 9 to drop to a predetermined temperature sufficiently lower than the predetermined temperature Tc described above.

0064Therefore, the running time in the "HV mode" is still the first predetermined time t._aIf it is negatively determined in step S8 because it has not reached, the process proceeds to step S9. Then, in step S9, the state in which both drives are prohibited is continued. That is, in this case, in order to continue to effectively cool the pinion gear 9 by the flood pressure generated by the MOP 18, the state in which both drive prohibition flags are turned ON is continued, and the running in the "HV mode" is continued. .. After that, this routine is terminated once.

0065On the other hand, the running time in the "HV mode" is the first predetermined time t._aIf the result is positively determined in step S8, the process proceeds to step S10. In step S10, the state in which both drives are prohibited is released. Specifically, both drive prohibition flags are turned off. In this case, it can be determined that the pinion gear 9 is sufficiently cooled by the flood pressure generated by the MOP 18. By turning off both drive prohibition flags, it becomes possible to shift from the "HV mode" to the "second EV mode" according to the required driving force and driving conditions. After that, this routine is terminated once.

0066On the other hand, when the "first EV mode" is set in step S7 above, it is determined whether or not there is an operation request for EOP21 (step S11). When running on a single drive, the engine 1 is stopped, so the oil supply by MOP18 is also stopped. Therefore, the oil is supplied to the planetary gear mechanism PG and the second motor 3 by the scraping lubrication mechanism 20. As described above, when the vehicle travels at a vehicle speed outside the predetermined vehicle speed range, or when the vehicle travels in a single drive for a long time, the oil supply by the scraping lubrication mechanism 20 may not be sufficient. In such a case, the EOP21 is operated, and the oil generated by the EOP21 is used to supply oil to the planetary gear mechanism PG and the second motor 3.

0067If it is negatively determined in step S11 because there is no operation request for EOP21, the process proceeds to step S9 described above, and the state in which both drives are prohibited is continued. That is, in this case, the state in which both drive prohibition flags are turned ON is continued, and the running in the "first EV mode" is continued. After that, this routine is terminated once.

0068On the other hand, if it is positively determined in step S11 due to the request for operation of EOP21, the process proceeds to step S12 and the operation of EOP21 is started. That is, the EOP 21 is driven by controlling the pump motor 22.

0069Next, the operating time of EOP21 is the second predetermined time t._{b b}It is determined whether it is longer than (step S13). 2nd predetermined time t_{b b}Is set to the time required for the pinion gear 9 to be sufficiently cooled after the operation of the EOP 21 is started. For example, the oil supplied to the pinion gear 9 by the EOP 21 sets the time required for the temperature of the pinion gear 9 to drop to a predetermined temperature sufficiently lower than the predetermined temperature Tc described above.

0070Therefore, the operating time of EOP21 is still the second predetermined time t._{b b}If it is negatively determined in step S13 because it has not reached, the process proceeds to step S9 described above, and the state in which both drives are prohibited is continued. That is, in this case, the state in which both drive prohibition flags are turned ON is continued, and the running in the "first EV mode" and the operation of the EOP 21 are continued. After that, this routine is terminated once.

0071On the other hand, the operating time of EOP21 is the second predetermined time t._{b b}If the result is positively determined in step S13, the process proceeds to step S10 described above, and the state in which both drives are prohibited is released. Specifically, both drive prohibition flags are turned off. In this case, it can be determined that the second motor 3 and the planetary gear mechanism PG are sufficiently cooled by the hydraulic pressure generated by the EOP21. By turning off both drive prohibition flags, it becomes possible to shift from the "first EV mode" to the "second EV mode" according to the required driving force and the driving situation. After that, this routine is terminated once.

0072The temperature behavior of the planetary gear mechanism PG when the control shown in the flowchart of FIG. 2 is executed is shown in the time chart of FIG. Time t₀From time t₁The motor is running with both drives. In this case, EOP21 operates to supply oil to the planetary gear mechanism PG, but the load applied to the pinion gear 9 is large due to the driving of the first motor 2, and the temperature of the planetary gear mechanism PG is rising. .. Time t₁After that, the temperature of the planetary gear mechanism PG decreases by shifting from the "second EV mode" to the "first EV mode" or the "HV mode".

0073Time t₂After that, the motor will run again with both drives, and the time t₃So, both drives are prohibited. For example, when the estimated temperature of the pinion gear 9, the pinion shaft 9a, the bearing, etc. reaches the upper limit temperature set as the threshold value of the temperature at which seizure may occur, the motor running by both drives is prohibited. Alternatively, a fail occurs in the EOP21, which makes it impossible for the EOP21 to operate normally, so that the motor running by both drives is prohibited.

0074Then, in the control by the controller 27, when the motor running by both drives is prohibited as described above, the running mode is shifted according to the estimated temperature of the pinion gear 9, the pinion shaft 9a, the bearing and the like. For example, as shown by the alternate long and short dash line in the time chart of FIG. 3, the time when both drives are prohibited (time t).₃), When the estimated temperature of the pinion gear 9, the pinion shaft 9a, the bearing, etc. exceeds the predetermined temperature Tc, the traveling mode of the vehicle Ve is changed from the "second EV mode" to the "HV mode".

0075When the engine 1 is operated by shifting to the "HV mode", the MOP18 is operated and the temperature of the planetary gear mechanism PG is lowered. And the running time in this "HV mode" is the first predetermined time t_aWhen it reaches (time t₄), The prohibition of both drives is lifted. Therefore, the "second EV mode" is set again, and the motor can be driven by both drives.

0076On the other hand, for example, as shown by the alternate long and short dash line in the time chart of FIG. 3, when both drives are prohibited (time t).₃), When the estimated temperature of the planetary gear mechanism PG is less than the predetermined temperature Tc, the traveling mode of the vehicle Ve is changed from the "second EV mode" to the "first EV mode".

0077By shifting to the "first EV mode" and stopping the drive of the first motor 2, the load applied to the planetary gear mechanism PG is reduced, and the temperature rise of the planetary gear mechanism PG is suppressed. Alternatively, as shown in the time chart of FIG. 3, the temperature of the planetary gear mechanism PG decreases. Time t₅By starting the operation of the EOP21 at, the temperature of the planetary gear mechanism PG is surely lowered. Then, the operating time of the EOP21 is the second predetermined time t._{b b}When it reaches (time t₆), The prohibition of both drives is lifted. Therefore, the "second EV mode" is set again, and the motor can be driven by both drives.

0078Note that FIG. 1 described above shows an example in which the electric oil pump EOP21 is provided as an alternative hydraulic source when the engine 1 is stopped and the MOP18 cannot be driven. As an alternative hydraulic source for MOP18, an oil pump as shown in FIGS. 4 and 5 below can also be used.

0079The oil pump 28 (hereinafter referred to as MOP28) shown in FIG. 4 is a mechanical oil pump having a conventional general configuration, similar to the above-mentioned MOP18. And this MOP28 is bets are transmitted from the drive shaft 5 side is configured to generate hydraulic pressure is driven by the torque. Specifically, the rotor of the MOP 28 (not shown) is configured to rotate with the drive shaft 5. Then, the oil discharged from the MOP 28 by generating the oil pressure of the MOP 28 is configured to be supplied to the planetary gear mechanism PG via the oil passage 29. Therefore, even when the rotation of the output shaft 1a of the engine 1 is stopped, the MOP 29 is driven when the vehicle Ve is running and the drive shaft 5 is rotating. Therefore, this MOP28 can generate oil and supply oil to the planetary gear mechanism PG. As shown in FIG. 4, the oil passage 29 can be configured as an independent oil passage connecting the MOP 28 and the planetary gear mechanism PG, but the oil is partially shared with the oil passage 19 described above. It can also be configured as a road.

0080By using such a MOP28, the amount of oil supplied to the pinion gear 9 increases as the vehicle speed increases. Therefore, the lubrication and cooling performance for the pinion gear 9 can be ensured even at high vehicle speeds.

0081The oil pump 30 (hereinafter referred to as MOP30) shown in FIG. 5 is a mechanical oil pump having a conventional general configuration, like the above-mentioned MOP18 and MOP28. The MOP30 is configured to generate flood control by being driven by the torque transmitted from the first motor 2. Specifically, the rotor of the MOP30 (not shown) is configured to rotate together with the rotor shaft 2b of the first motor 2. Then, the oil discharged from the MOP30 when the MOP30 generates a hydraulic pressure is supplied to the planetary gear mechanism PG via the oil passage 31. Therefore, even when the rotation of the output shaft 1a of the engine 1 is stopped, the MOP30 is driven in the state where the first motor 2 is rotating. Therefore, this MOP30 can generate oil and supply oil to the planetary gear mechanism PG.

0082By using such a MOP30, it is possible to obtain an oil discharge amount corresponding to the rotation speed of the first motor 2. Therefore, the lubrication and cooling performance for the pinion gear 9 can be ensured even when the first motor 2 is driven by both drives that output torque.

00831 ... engine (driving power source; ENG), 2 ... 1st motor (driving power source; MG1), 3 ... 2nd motor (driving power source; MG2), 4 ... power splitting device , 4a ... input shaft, 5 ... drive shaft, 6 ... sun gear, 7 ... ring gear, 8 ... carrier, 9 ... pinion gear, 9a ... pinion shaft, 10 ... One-way clutch (brake mechanism), 14 ... differential gear, 15 ... ring gear, 18,28,30 ... oil pump (MOP), 20 ... scraping lubrication mechanism, 21 ... oil pump ( Electric oil pump; EOP), 22 ... pump motor, 24 ... vehicle speed sensor, 25 ... oil temperature sensor, 26 ... rotation speed sensor, 27 ... controller (ECU), PG .. .Planetary gear mechanism, Ve ... Vehicle (hybrid vehicle).