JP4909134B2 - Powertrain control device, control method, program for realizing the method, and recording medium recording the program - Google Patents

Description

  The present invention relates to a power train control device, a control method, a program for realizing the method, and a recording medium on which the program is recorded. In particular, the engine is stopped when a shift operation from a non-travel position to a travel position is performed. Related to technology.

  Conventionally, a hybrid vehicle having an engine and a rotating electric machine as drive sources is known. In such a hybrid vehicle, an engine and a rotating electric machine are selectively used according to the traveling state of the vehicle. For example, the vehicle travels mainly using an engine when traveling at a high speed, and travels mainly using a rotating electrical machine when traveling at a medium or low speed. One such hybrid vehicle includes a multi-stage automatic transmission in addition to a differential mechanism that functions as a continuously variable transmission using a rotating electrical machine.

  Japanese Patent Laying-Open No. 2005-337491 (Patent Document 1) includes a first element coupled to an engine, a second element coupled to a first electric motor (rotating electric machine), and a third element coupled to a second electric motor. Control of a vehicle drive device comprising a continuously variable transmission having a configured differential mechanism and functioning as an electric continuously variable transmission, and a transmission provided between the continuously variable transmission and the wheels An apparatus is disclosed. In the control device described in Patent Document 1, the gear of the continuously variable transmission unit is synchronized with the shift so that the gear ratio formed by the continuously variable transmission unit and the transmission unit is continuous when the transmission unit shifts. Including a continuously variable transmission control unit.

According to the control device described in this publication, the gear ratio formed by the continuously variable transmission unit and the transmission unit, that is, the gear ratio formed based on the transmission ratio of the continuously variable transmission unit and the transmission gear ratio. The overall gear ratio is continuously changed. As a result, the engine speed (the number of revolutions) is continuously changed before and after the speed change of the speed change unit to reduce the speed change shock.
JP 2005-337491 A

  By the way, when a multi-stage automatic transmission is connected to the differential mechanism, when the multi-stage automatic transmission is switched from a neutral state to a state in which a gear stage is formed, the rotation of the rotary element connected to the input shaft of the multi-stage automatic transmission The number changes step by step. Due to the characteristics of the differential mechanism, when the rotational speed of at least one of the three rotational elements changes, the rotational speed of the other rotational elements changes. Therefore, when the rotational speed of the rotary element connected to the input shaft of the multi-stage automatic transmission changes stepwise, the rotational speed of the rotary element different from the rotary element connected to the engine is used with the engine speed as a fulcrum in the alignment chart. The number changes greatly. At this time, depending on the engine speed, the rotational speed of the rotating element may be excessively high. However, Japanese Patent Application Laid-Open No. 2005-337491 has no description regarding such a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to control a power train, a control method, and a method thereof that can prevent the rotational speed of a rotating element from becoming excessively high. And a recording medium on which the program is recorded.

  The power train control device according to the first invention has a first rotating element, a second rotating element, and a third rotating element, and the remaining one according to the number of rotations of any two rotating elements. A differential mechanism that changes the number of rotations of the rotating element, a rotating electrical machine that is connected to the first rotating element, and a torque that is connected to the second rotating element and is input from the second rotating element to the wheels. A control apparatus for a power train, comprising: a switching mechanism capable of switching between a state and a state in which transmission of torque from a second rotating element to a wheel is cut off; and an engine coupled to the third rotating element. The control device is configured to determine whether to stop the engine when the shift operation from the non-travel position to the travel position is performed, and to stop when it is determined to stop the engine. Means for controlling the engine and for controlling the switching mechanism so as to switch from a state where the transmission of torque from the second rotating element to the wheel is interrupted to a state where torque is transmitted to the wheel after the engine is stopped Means. The power train control method according to the fifth invention has the same requirements as those of the power train control device according to the first invention.

  According to the first or fifth invention, the differential mechanism has a first rotating element, a second rotating element, and a third rotating element. The rotation speed of the remaining one rotation element changes according to the rotation speed of any two rotation elements. A rotating electrical machine is coupled to the first rotating element. A switching mechanism is coupled to the second rotating element. The switching mechanism can switch between a state in which torque input from the second rotating element is transmitted to the wheel and a state in which transmission of torque from the second rotating element to the wheel is interrupted. An engine is connected to the third rotating element. When the shift operation from the non-travel position to the travel position is performed, it is determined whether or not to stop the engine. If it is determined to stop the engine, the engine is stopped. After the engine is stopped, the switching mechanism is controlled so as to switch from the state where the transmission of torque from the second rotating element to the wheel is interrupted to the state where torque is transmitted to the wheel. Thereby, in a state where the engine is stopped, it is possible to switch from a state where transmission of torque from the second rotating element to the wheel is interrupted to a state where torque is transmitted to the wheel. Therefore, even when the rotational speed of the second rotating element is changed stepwise by switching from the state of interrupting the transmission of torque to the wheel from the second rotating element to the state of transmitting the torque to the wheel, It is possible to prevent the rotation speed of the first rotation element from becoming excessively high. As a result, it is possible to provide a control apparatus or control method for a power train that can prevent the rotational speed of the rotating element from becoming excessively high.

  In the control apparatus for the power train according to the second invention, in addition to the configuration of the first invention, the judging means judges whether or not to stop the engine based on the output shaft rotational speed of the switching mechanism. Including means. The power train control method according to the sixth aspect has the same requirements as those of the power train control apparatus according to the second aspect.

  According to the second or sixth invention, it is determined whether or not to stop the engine based on the output shaft rotational speed of the switching mechanism. Thereby, the rotation speed of the first rotation element may be excessively increased by using the output shaft rotation speed of the switching mechanism that can affect the rotation speed of the first rotation element via the second rotation element. It is possible to determine whether or not to stop the engine while considering whether or not there is. Therefore, it is possible to prevent the engine from being stopped when the rotation speed of the first rotation element is appropriate. As a result, the engine can be prevented from being stopped unnecessarily.

  In the power train control device according to the third invention, in addition to the configuration of the second invention, the judging means stops the engine when the output shaft rotational speed of the switching mechanism is within a predetermined region. Means for determining. The power train control method according to the seventh invention has the same requirements as those of the power train control device according to the third invention.

  According to the third or seventh invention, whether or not to stop the engine can be determined based on whether or not the output shaft rotational speed of the switching mechanism is within a predetermined region.

  In the power train control device according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the first rotating element is a sun gear. The second rotating element is a ring gear. The third rotating element is a carrier that rotatably supports a pinion gear that meshes with the sun gear and the ring gear. The power train control method according to the eighth invention has the same requirements as those of the power train control device according to the fourth invention.

  According to the fourth or eighth aspect of the invention, in the differential mechanism having the sun gear connected to the rotating electrical machine, the ring gear connected to the switching mechanism, and the carrier connected to the engine, the rotational speed of the sun gear is prevented from becoming excessive. be able to.

  A program according to a ninth aspect is a program for causing a computer to realize the control method according to any of the fifth to eighth aspects, and the recording medium according to the tenth aspect is any one of the fifth to eighth aspects. It is a computer-readable recording medium which recorded the program which makes a computer implement | achieve the control method which concerns on invention.

  According to the ninth or tenth invention, the power train control method according to any one of the fifth to eighth inventions can be realized by using a computer (which may be general purpose or dedicated).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A hybrid vehicle equipped with a control device according to an embodiment of the present invention will be described with reference to FIG. This hybrid vehicle is an FR (Front engine Rear drive) vehicle. A vehicle other than FR may be used.

  The hybrid vehicle includes a hybrid system 100 as a drive source, an automatic transmission 400, a propeller shaft 500, a differential gear 600, a rear wheel 700, and an ECU (Electronic Control Unit) 800. The control device according to the present embodiment is realized, for example, by executing a program recorded in ROM (Read Only Memory) 802 of ECU 800. The program executed by ECU 800 may be recorded on a recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc) and distributed to the market. ECU 800 may be divided into a plurality of ECUs.

  The hybrid vehicle power train includes a hybrid system 100 and an automatic transmission 400. The engine 200 of the hybrid system 100 is an internal combustion engine that burns a mixture of fuel and air injected from an injector 202 in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated.

  Automatic transmission 400 is coupled to the output shaft of hybrid system 100. The driving force output from the automatic transmission 400 is transmitted to the left and right rear wheels 700 via the propeller shaft 500 and the differential gear 600.

  The ECU 800 includes a position switch 806 for the shift lever 804, an accelerator opening sensor 810 for the accelerator pedal 808, a depression force sensor 814 for the brake pedal 812, a throttle opening sensor 818 for the electronic throttle valve 816, and an engine speed sensor 820. The input shaft speed sensor 822, the output shaft speed sensor 824, and the oil temperature sensor 826 are connected via a harness or the like.

  The position (position) of shift lever 804 is detected by position switch 806, and a signal representing the detection result is transmitted to ECU 800. Corresponding to the position of the shift lever 804, a shift in the automatic transmission 400 is automatically performed. By operating the shift lever 804, the driver may be able to select a desired gear (gear ratio).

  Accelerator opening sensor 810 detects the opening of accelerator pedal 808 and transmits a signal representing the detection result to ECU 800. The pedaling force sensor 814 detects the pedaling force of the brake pedal 812 (the force with which the driver steps on the brake pedal 812), and transmits a signal representing the detection result to the ECU 800.

  The throttle opening sensor 818 detects the opening of the electronic throttle valve 816 whose opening is adjusted by the actuator, and transmits a signal indicating the detection result to the ECU 800. The electronic throttle valve 816 adjusts the amount of air taken into the engine 200 (output of the engine 200).

  Instead of or in addition to the electronic throttle valve 816, the amount of air sucked into the engine 200 is changed by changing the lift amount of the intake valve (not shown) or the exhaust valve (not shown) and the opening / closing phase. You may make it adjust.

  Engine rotation speed sensor 820 detects the rotation speed (engine rotation speed NE) of the output shaft (crankshaft) of engine 200 and transmits a signal representing the detection result to ECU 800. Input shaft speed sensor 822 detects input shaft speed NI of automatic transmission 400 and transmits a signal representing the detection result to ECU 800. Output shaft rotational speed sensor 824 detects output shaft rotational speed NO of automatic transmission 400 and transmits a signal representing the detection result to ECU 800.

  The vehicle speed of the hybrid vehicle is calculated from the output shaft rotational speed NO of automatic transmission 400. In addition, about the method of calculating a vehicle speed, what is necessary is just to use a known general technique, Therefore The detailed description is not repeated here.

  Oil temperature sensor 826 detects the temperature (oil temperature) of oil (ATF: Automatic Transmission Fluid) used for the operation and lubrication of automatic transmission 400 and transmits a signal representing the detection result to ECU 800.

  ECU 800 is sent from position switch 806, accelerator opening sensor 810, pedal effort sensor 814, throttle opening sensor 818, engine speed sensor 820, input shaft speed sensor 822, output shaft speed sensor 824, oil temperature sensor 826, and the like. Based on the received signal, the map stored in the ROM 802, and the program, the devices are controlled so that the vehicle is in a desired running state.

  The hybrid system 100 and the automatic transmission 400 will be further described with reference to FIG.

  Hybrid system 100 includes an engine 200, a power split mechanism 310, a first MG (Motor Generator) 311, and a second MG 312. Power split device 310 splits the output of engine 200 input to input shaft 302 into first MG 311 and output shaft 304. Power split device 310 includes planetary gear 320.

  Planetary gear 320 includes a sun gear 322, a pinion gear 324, a carrier 326 that supports the pinion gear 324 so as to rotate and revolve, and a ring gear 328 that meshes with the sun gear 322 via the pinion gear 324.

  In power split device 310, carrier 326 is connected to input shaft 302, that is, engine 200. Sun gear 322 is connected to first MG 311. Ring gear 328 is coupled to output shaft 304.

  Power split device 310 functions as a differential device by relatively rotating sun gear 322, carrier 326, and ring gear 328. Due to the differential function of power split device 310, the output of engine 200 is distributed to first MG 311 and output shaft 304.

  The first MG 311 generates electric power using a part of the output of the distributed engine 200, or the second MG 312 is rotationally driven using electric power generated by the first MG 311 so that the power split mechanism 310 is a continuously variable transmission. Function as.

  First MG 311 and second MG 312 are three-phase AC rotating electric machines. First MG 311 is coupled to sun gear 322 of power split device 310. Second MG 312 is provided such that the rotor rotates integrally with output shaft 304.

  First MG 311 and second MG 312 are controlled so as to satisfy the target output torque of automatic transmission 400 calculated from, for example, the accelerator opening and the vehicle speed, and to realize optimum fuel consumption in engine 200. The output torque of second MG 312 is determined according to a map that defines the ratio of the output torque of engine 200 and the output torque of second MG 312 to the target output torque.

  As shown in FIG. 3, the rotational speed of first MG 311, the rotational speed of second MG 312, and engine rotational speed NE are in a relationship connected by a straight line in the nomographic chart. Therefore, as indicated by the alternate long and short dash line in FIG. 3, when the rotation speed of the second MG 312 changes, the rotation speed of the first MG 311 changes. Further, as indicated by a two-dot chain line in FIG. 3, the rotational speed of the first MG 311 changes according to the engine rotational speed NE.

  In the present embodiment, first MG 311, second MG 312, and engine 200 are configured so as to protect power train, so that rotation speed NR of ring gear 328 of power split mechanism 310 (input shaft speed NI of automatic transmission 400) and engine speed NE (The rotation speed of the carrier 326) is controlled so as to be within an allowable region indicated by hatching in FIG.

  The allowable range is determined in consideration of the lower limit value NSL, the upper limit value NSH, the lower limit value PINL and the upper limit value PINH of the rotation speed of the first MG 311 (the rotation speed of the sun gear 322) of the pinion gear 324. That is, the first MG 311, the second MG 312, and the first MG 311 so that the rotation speed of the first MG 311 is not less than the lower limit value NSL and not more than the upper limit value NSH and the rotation speed of the pinion gear 324 is not less than the lower limit value PINL and not more than the upper limit value PINH. The engine 200 is controlled. The rotation speed of the pinion gear 324 is a relative rotation speed between the rotation speed NR of the ring gear 328 and the rotation speed of the carrier 326.

  In the present embodiment, the ring gear when the hybrid vehicle is moving forward in the state where the forward gear stage is formed in the automatic transmission 400 or when the vehicle is moving backward while the reverse gear stage is formed. The rotational speed NR is expressed as a positive value. That is, in the automatic transmission 400, the rotational direction of the ring gear 328 is the same when the hybrid vehicle is moving forward when the forward gear is formed and when the hybrid vehicle is moving backward when the reverse gear is formed. .

  When the hybrid vehicle is moving backward in a state where the forward gear stage is formed in the automatic transmission 400, or when the hybrid vehicle is moving forward in a state where the reverse gear stage is formed, the ring gear rotational speed NR becomes a negative value.

  Returning to FIG. 2, the automatic transmission 400 includes an input shaft 404 as an input rotating member disposed on a common axis in a case 402 as a non-rotating member attached to the vehicle body, and an output as an output rotating member. Axis 406.

  Input shaft 404 is connected to output shaft 304 of power split device 310. Therefore, the input shaft rotational speed NI of automatic transmission 400 and the output shaft rotational speed of power split device 310, that is, the rotational speed of ring gear 328 (the rotational speed of second MG 312) NR are the same.

  Automatic transmission 400 includes three planetary gears 411 to 413 of a single pinion type, and five friction engagement elements of C1 clutch 421, C2 clutch 422, B1 brake 431, B2 brake 432, and B3 brake 433.

  By engaging the friction engagement elements of the automatic transmission 400 in the combinations shown in the operation table shown in FIG. 5, the five forward gears and the reverse gears of the first to fifth gears having different gear ratios in the power train are provided. A gear stage is formed.

  In a state where the gear stage is formed in automatic transmission 400, torque (output torque of hybrid system 100) input from ring gear 328 of power split mechanism 310 to automatic transmission 400 is transmitted to rear wheel 700 that is a drive wheel.

  When the shift lever 804 is in a travel position such as the D (drive) position or the R (reverse) position and the travel range is selected, a gear stage is formed in the power train.

  On the other hand, when shift lever 804 is in a non-traveling position such as an N (neutral) position and the non-traveling range is selected, automatic transmission 400 is set to the neutral state.

  In the neutral state of automatic transmission 400, all the frictional engagement elements are released. In the neutral state, transmission of torque from the ring gear 328 of the power split mechanism 310 to the rear wheel 700 is interrupted.

  As shown in FIG. 5, the friction engagement element that is engaged when forming the fourth speed gear stage and the friction engagement element that is engaged when forming the fifth speed gear stage are the same. That is, the gear ratio in automatic transmission 400 is the same between the fourth gear and the fifth gear. However, the gear ratio in power split mechanism 310 is different.

  When the 4-speed gear stage is formed, the power split mechanism 310 allows the rotation of the first MG 311 so that the engine speed and the output shaft 304 are the same, and the gear ratio is “1”. On the other hand, when forming the fifth gear, the rotation speed of the first MG 311 is set to “0”, so that the rotation speed of the output shaft 304 is made higher than the engine rotation speed, and the transmission ratio is set to “1”. Is also made smaller.

  The shift in the power train is controlled based on, for example, a shift diagram shown in FIG. The shift map in the present embodiment is determined by using the target output torque calculated from the accelerator opening and the vehicle speed, and the vehicle speed as parameters. Note that the parameters of the shift map are not limited to these.

  The solid line in FIG. 6 is an upshift line, and the broken line is a downshift line. In FIG. 6, a region surrounded by a one-dot chain line indicates a region that travels using only the driving force of the second MG 312 without using the driving force of the engine 200.

  The C1 clutch 421, the C2 clutch 422, the B1 brake 431, the B2 brake 432, and the B3 brake 433 of the automatic transmission 400 are operated by hydraulic pressure. In the present embodiment, as shown in FIG. 7, the hybrid vehicle is provided with a hydraulic pressure control device 900 that supplies and discharges hydraulic pressure to and from each friction engagement element and controls engagement / release.

  The hydraulic control apparatus 900 adjusts the hydraulic pressure generated by the mechanical oil pump 910, the electric oil pump 920, and the oil pumps 910 and 920 to the line pressure, and the hydraulic pressure adjusted using the line pressure as the original pressure. And a hydraulic circuit 930 that supplies oil for lubrication to an appropriate location.

  Mechanical oil pump 910 is a pump that is driven by engine 200 to generate hydraulic pressure. The mechanical oil pump 910 is disposed coaxially with the carrier 326 and is operated by receiving torque from the engine 200. That is, when the carrier 326 rotates, the mechanical oil pump 910 is driven, and hydraulic pressure is generated.

  On the other hand, the electric oil pump 920 is a pump driven by a motor (not shown). The electric oil pump 920 is attached to an appropriate location such as the outside of the transmission case. Electric oil pump 920 is controlled by ECU 800 to generate a desired oil pressure. For example, the rotational speed of the electric oil pump 920 is feedback-controlled.

  The rotational speed of electric oil pump 920 is detected by rotational speed sensor 830, and a signal representing the detection result is transmitted to ECU 800. Further, the discharge pressure from the electric oil pump 920 is detected by the hydraulic sensor 832, and a signal indicating the detection result is transmitted to the ECU 800.

  The electric oil pump 920 is operated by electric power supplied from the battery 942 via the DC / DC converter 940. The electric power of the battery 942 is supplied not only to the electric oil pump 920 but also to auxiliary devices that are operated by electric power, such as the electric power steering 950, the first MG 312 and the second MG 312.

  The charge / discharge current value from battery 942 is detected by current sensor 834, and a signal representing the detection result is transmitted to ECU 800. In the present embodiment, the SOC (State Of Charge) of battery 942 is calculated based on the charge / discharge current value from battery 942. In addition, since it is sufficient to use a known general technique for calculating the SOC, detailed description thereof will not be repeated here. The temperature of battery 942 is detected by temperature sensor 836 and a signal representing the detection result is transmitted to ECU 800.

  The hydraulic circuit 930 includes a plurality of solenoid valves, switching valves, or pressure regulating valves (each not shown), and is configured to be able to electrically control pressure regulation and hydraulic supply / discharge. The control is performed by the ECU 800.

  In addition, check valves 912 and 922 that open at the discharge pressure of the oil pumps 910 and 920 and close in the opposite direction are provided on the discharge side of the oil pumps 910 and 920, and the hydraulic circuit 930 includes On the other hand, these oil pumps 910 and 920 are connected in parallel to each other. 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.

  With reference to FIG. 8, the function of ECU 800 serving as the control device according to the present embodiment will be described. The functions of ECU 800 described below may be realized by hardware or may be realized by software.

  ECU 800 includes a shift operation determination unit 840, a stop determination unit 842, a stop unit 844, and an engagement unit 846.

  Based on the signal transmitted from position switch 806, shift operation determination unit 840 determines whether or not a shift operation (operation of shift lever 804) from the N position to the D position or from the N position to the R position is performed. .

  Stop determination unit 842 determines whether to stop engine 200 to protect the power train when a shift operation from the N position to the D position or from the N position to the R position is performed.

  Whether to stop the engine 200 is determined based on the output shaft rotational speed NO of the automatic transmission 400.

  When the shift operation from the N position to the D position is performed, as shown in FIG. 9, the engine 200 is stopped when the output shaft rotational speed NO of the automatic transmission 400 is within the threshold value (A) or less. It is judged.

  In FIG. 9, the hatched area indicates the output shaft rotational speed NO of the automatic transmission 400 by dividing the rotational speed NR of the ring gear 328 used as a parameter in the allowable area shown in FIG. 4 above by the gear ratio of the forward gear. This is an allowable area obtained as a result of conversion to. Therefore, an allowable range using the output shaft rotational speed NO of automatic transmission 400 instead of rotational speed NR of ring gear 328 is determined for each gear stage.

  When the shift operation from the N position to the R position is performed, as shown in FIG. 10, the engine 200 is stopped when the output shaft rotational speed NO of the automatic transmission 400 is within the threshold value (B) or more. It is judged.

  In FIG. 10, the shaded area indicates the output shaft rotational speed NO of the automatic transmission 400 by dividing the rotational speed NR of the ring gear 328 used as a parameter in the allowable area shown in FIG. 4 above by the gear ratio of the reverse gear. This is an allowable area obtained as a result of conversion into

  In the present embodiment, output shaft speed NO when the hybrid vehicle is moving forward is represented as a positive value. The output shaft rotational speed NO when the hybrid vehicle is moving backward is expressed as a negative value.

  9 and 10, the value indicated by the two-dot chain line indicates the lower limit value of the engine speed NE. That is, if the engine speed NE of the automatic transmission 400 cannot reach a value within the allowable range unless the engine 200 is stopped as in the case where the engine speed NE is smaller than the lower limit value, the engine 200 is turned off. It is determined to stop.

  On the contrary, when the engine speed NE is larger than the lower limit value, even when the engine 200 is in operation, the output shaft speed NO of the automatic transmission 400 can be within the allowable range. It is not determined to stop engine 200.

  Stop unit 844 controls engine 200 to stop when a shift operation from the N position to the D position or from the N position to the R position is performed and determination is made to stop engine 200.

  When the shift operation from the N position to the D position or from the N position to the R position is performed, the engagement portion 846 forms a gear stage, that is, engages the clutch and brake that are friction engagement elements after the engine 200 is stopped. The automatic transmission 400 is controlled to start the combination. Therefore, the neutral state is switched to a state in which the torque of the ring gear 328 is transmitted to the rear wheel 700.

  With reference to FIG. 11, a control structure of a program executed by ECU 800 serving as the control apparatus according to the present embodiment will be described. The program described below is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as S) 100, ECU 800 determines whether or not a shift operation from the N position to the D position or from the N position to the R position is performed based on a signal transmitted from position switch 806. Judging.

  When a shift operation from the N position to the D position or from the N position to the R position is performed (YES in S100), the process proceeds to S102. Otherwise (NO in S100), this process ends.

  In S102, ECU 800 determines whether engine 200 is to be stopped based on output shaft rotational speed NO of automatic transmission 400 or not. When the shift operation from the N position to the D position is performed, it is determined that the engine 200 is stopped if the output shaft rotational speed NO of the automatic transmission 400 is in the region equal to or less than the threshold value (A) described above. When the shift operation from the N position to the R position is performed, it is determined that the engine 200 is stopped if the output shaft rotational speed NO of the automatic transmission 400 is within the above-described threshold (B) or more.

  If it is determined that engine 200 is to be stopped (YES in S102), the process proceeds to S104. If not (NO in S102), the process proceeds to S108. In S104, ECU 800 controls engine 200 to stop.

  In S106, ECU 800 determines whether engine 200 has stopped. For example, when engine speed NE is lower than a threshold value, it is determined that engine 200 has stopped. When engine 200 is stopped (YES in S106), the process proceeds to S108. If not (NO in S106), the process returns to S106.

  In S108, ECU 800 controls automatic transmission 400 to start the formation of the forward gear or the reverse gear, that is, the engagement of the friction engagement element. That is, the neutral state is switched to a state in which the torque of the ring gear 328 is transmitted to the rear wheel 700. When a shift operation from the N position to the D position is performed, a forward gear stage is formed. When a shift operation from the N position to the R position is performed, a reverse gear stage is formed.

  An operation of ECU 800 serving as the control device according to the present embodiment based on the above-described structure and flowchart will be described.

  If a shift operation from the N position to the D position is performed during the reverse travel of the hybrid vehicle and a forward gear stage is formed, or a shift operation from the N position to the R position is performed during the forward travel, a reverse gear stage is formed. As indicated by a broken line in FIG. 12, the ring gear rotation speed NR can be reversed from a positive value to a negative value. In this case, if the engine speed NE is high, the speed of the first MG 311 may be excessively high.

  That is, as indicated by the black dots in FIG. 13, when the shift operation from the N position to the D position is performed, the output shaft rotational speed NO of the automatic transmission 400 is smaller than the threshold value (A) and the engine rotational speed NE is If it is high, the forward gear stage is formed, so that the rotational speed of the first MG 311 may be excessively high.

  Similarly, as indicated by the black dots in FIG. 14, when the shift operation from the N position to the R position is performed, the output shaft rotational speed NO of the automatic transmission 400 is larger than the threshold value (B) and the engine rotational speed NE. If it is high, the reverse gear stage is formed, so that the rotational speed of the first MG 311 can be excessively high.

  Therefore, when a shift operation from the N position to the D position or from the N position to the R position is performed (YES in S100), whether engine 200 is to be stopped based on the output shaft rotational speed NO of automatic transmission 400 is determined. Is determined (S102).

  When the shift operation from the N position to the D position is performed and the output shaft rotational speed NO of the automatic transmission 400 is in the region below the threshold value (A), or the shift operation from the N position to the R position. And the output shaft rotational speed NO is within the above-described threshold (B) or more, the rotational speed of the first MG 311 can be excessively high. In these cases, determination is made to stop engine 200 (YES in S102).

  If it is determined that engine 200 is to be stopped (YES in S102), engine 200 is controlled to stop (S104). When engine 200 stops (YES in S106), automatic transmission 400 is controlled to start the formation of the forward gear or the reverse gear (S108). That is, the neutral state is switched to a state in which the torque of the ring gear 328 is transmitted to the rear wheel 700.

  Thereby, after the engine 200 is stopped, the forward gear or the reverse gear can be formed. That is, the forward gear or the reverse gear can be formed with the engine 200 stopped. Therefore, as indicated by the alternate long and short dash line in FIG. 15, the rotational speed of first MG 311, that is, the rotational speed of sun gear 322 of power split device 310 can be prevented from becoming excessively high.

  As described above, according to the ECU that is the control device according to the present embodiment, it is determined whether or not to stop the engine when a shift operation from the N position to the D position or from the N position to the R position is performed. Is done. When it is determined that the engine is to be stopped, the engine is stopped. After the engine is stopped, the automatic transmission is controlled to start the formation of the forward gear or the reverse gear. Thus, the forward gear or the reverse gear can be formed with the engine stopped. Therefore, it is possible to prevent the rotation speed of the sun gear of the power split mechanism from changing excessively according to the rotation speed of the ring gear and the engine rotation speed NE, that is, the rotation speed of the carrier.

  In addition, instead of making it possible to form five forward gears in the power train, four forward gears from the first gear to the fourth gear may be formed. When the power train is configured so that four forward gears can be formed, as shown in FIG. 16, the automatic transmission 400 includes two single-pinion type planetary gears 441 and 442, a C1 clutch 451, and a C2 clutch 452. , Four friction engagement elements of B1 brake 461 and B2 brake 462.

  By engaging the friction engagement elements in the combinations shown in the operation table shown in FIG. 17, four forward gears from the first gear to the fourth gear are formed.

  The friction engagement element that is engaged when forming the third speed gear stage is the same as the friction engagement element that is engaged when forming the fourth speed gear stage. That is, the gear ratio in automatic transmission 400 is the same between the third gear and the fourth gear. However, the gear ratio in power split mechanism 310 is different.

  When the third speed gear stage is formed, the power split mechanism 310 allows the first MG 311 to rotate, the engine speed and the output shaft 304 are made the same, and the gear ratio is “1”. On the other hand, when the 4-speed gear stage is formed, the rotational speed of the first MG 311 is set to “0”, so that the rotational speed of the output shaft 304 is made higher than the engine rotational speed, and the transmission ratio is set to “1”. Is also made smaller. The shift in the power train is controlled based on, for example, a shift diagram shown in FIG.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram which shows the hybrid vehicle carrying the control apparatus which concerns on embodiment of this invention. It is a figure (the 1) which shows a hybrid system and an automatic transmission. It is a figure (the 1) which shows the alignment chart of a power split device. It is a figure which shows the lower limit of the rotation speed of MG1, an upper limit, etc. It is a figure (the 1) which shows an operation | movement table | surface. FIG. 3 is a diagram (part 1) illustrating a shift diagram. It is a figure which shows a hydraulic control apparatus. It is a functional block diagram of ECU. It is FIG. (The 1) which shows the threshold value (A) etc. which are used in order to judge whether an engine is stopped. It is FIG. (1) which shows the threshold value (B) etc. which are used in order to judge whether an engine is stopped. It is a flowchart which shows the control structure of the program which ECU performs. FIG. 8 is a second diagram showing a nomographic chart of the power split mechanism. FIG. 10 is a diagram (part 2) illustrating a threshold value (A) used for determining whether or not to stop the engine. It is FIG. (The 2) which shows the threshold value (B) etc. which are used in order to judge whether an engine is stopped. FIG. 9 is a third diagram illustrating a nomographic chart of the power split mechanism. FIG. 2 is a diagram (part 2) illustrating a hybrid system and an automatic transmission. It is a figure (the 2) which shows an operation | movement table | surface. It is a figure (the 2) which shows a shift map.

Explanation of symbols

  100 hybrid system, 200 engine, 310 power split mechanism, 311 1st MG, 312 2nd MG, 320 planetary gear, 322 sun gear, 324 pinion gear, 326 carrier, 328 ring gear, 400 automatic transmission, 500 propeller shaft, 600 differential gear, 700 rear wheel , 800 ECU, 802 ROM, 804 shift lever, 806 position switch, 808 accelerator pedal, 810 accelerator opening sensor, 812 brake pedal, 814 pedal force sensor, 816 electronic throttle valve, 818 throttle opening sensor, 820 engine speed sensor, 822 Input shaft rotational speed sensor, 824 Output shaft rotational speed sensor, 840 Shift operation determination unit, 842 Stop determination Part, 844 stop part, 846 engaging part.

Claims (8)

Sun, ring gear, and a differential mechanism that having a carrier which rotatably supports the meshed pinion gear and the said sun gear, a rotary electric machine coupled to the sun gear is connected to the ring gear, the ring gear A power train control device comprising: a transmission capable of switching between a state in which torque input from a wheel is transmitted to a wheel and a state in which transmission of torque from the ring gear to the wheel is interrupted; and an engine coupled to the carrier Because
When the shift operation from the non-travel position to the forward travel position is performed and the output shaft rotational speed of the transmission is within the first threshold value that is less than the first threshold value less than zero, or the reverse travel from the non-travel position shifting operation to the drive position is performed, and the rotational speed of the output shaft of the transmission, if a zero is greater than a second threshold value or more in the region, determining for determining to stop the engine Means,
Means for controlling the engine to stop if it is determined to stop the engine;
Means for controlling the transmission so as to switch from a state in which transmission of torque from the ring gear to the wheels is interrupted to a state in which torque is transmitted to the wheels after the engine is stopped. Control device. The absolute value of the first threshold value is the rotational speed of the ring gear when the output shaft rotational speed of the engine is a lower limit value and the rotational speed of the sun gear is an upper limit value. The power train control device according to claim 1, which is equal to a value divided by a gear ratio of the gear stage. The absolute value of the second threshold is the reverse speed of the ring gear when the output shaft rotational speed of the engine is a lower limit value and the rotational speed of the sun gear is an upper limit value. The power train control device according to claim 1, which is equal to a value divided by a gear ratio of the gear stage. Sun, ring gear, and a differential mechanism that having a carrier which rotatably supports the meshed pinion gear and the said sun gear, a rotary electric machine coupled to the sun gear is connected to the ring gear, the ring gear Power train control method comprising: a transmission capable of switching between a state of transmitting torque input from a wheel to a wheel and a state of interrupting transmission of torque from the ring gear to the wheel; and an engine coupled to the carrier Because
When the shift operation from the non-travel position to the forward travel position is performed and the output shaft rotational speed of the transmission is within the first threshold value that is less than the first threshold value less than zero, or the reverse travel from the non-travel position a step of shifting operation to drive position is performed, and the rotational speed of the output shaft of the transmission, if a zero is greater than a second threshold value or more in the region, it is determined to stop the engine,
If it is determined to stop the engine, controlling the engine to stop;
Controlling the transmission so as to switch from a state in which transmission of torque from the ring gear to the wheel is interrupted to a state in which torque is transmitted to the wheel after the engine is stopped. Method. The absolute value of the first threshold value is the rotational speed of the ring gear when the output shaft rotational speed of the engine is a lower limit value and the rotational speed of the sun gear is an upper limit value. The power train control method according to claim 4, wherein the power train control method is equal to a value divided by a gear ratio of the gear stage. The absolute value of the second threshold is the reverse speed of the ring gear when the output shaft rotational speed of the engine is a lower limit value and the rotational speed of the sun gear is an upper limit value. The power train control method according to claim 4, wherein the power train control method is equal to a value divided by a gear ratio of the gear stage. Program for implementing the control method according to the computer in any one of claims 4-6. A computer-readable recording medium having recorded thereon a program for causing a computer to implement the control method according to any one of claims 4 to 6 .

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