JP2008201288A - Control unit of power train, control method, program which materializes its method, and recording medium which records its program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a rotation rate of a rotary electric machine not to become excessively large during sudden deceleration of a vehicle. <P>SOLUTION: An ECU executes a program which includes; a step for detecting an accelerator opening (S100); a step for detecting a stroke amount of a brake pedal (S110); a step for detecting a rotation rate NR of a sun gear to which a first MG is connected, and a ring gear of a power dividing mechanism having a carrier to which an engine is connected (S120); and a step to execute processing to restrict a load factor of an engine to an upper value KLH or below, when both accelerator operation and brake operation are performed and vehicle speed decreases rapidly (YES at S130), or in other words when the rotation rate of the ring gear decreases rapidly without falling of the rotation rate NE of the engine (S140). <P>COPYRIGHT: (C)2008,JPO&INPIT

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, and more particularly to a technique for reducing the engine speed during deceleration.

  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 is equipped with a differential mechanism having a rotating element connected to a rotating electrical machine and a rotating element connected to an engine.

  Japanese Patent Application Laid-Open No. 2004-153946 (Patent Document 1) discloses that four elements of a main power source, a first motor (rotary electric machine), a second motor, and an output member are the first motor and main power source on the collinear diagram. A motor over-rotation prevention control device for a hybrid vehicle equipped with a hybrid drive system having a gear mechanism (differential mechanism) connected so as to be in the order of the rotation speed of the output member and the second motor is disclosed. This motor over-rotation prevention control device sets the gear ratio so that the operating point of the main power source is on the optimum energy efficiency line, and the rotational speeds of the first motor and the second motor calculated based on the gear ratio setting. Among these, when the rotational speed of one of the motors is determined to be over-rotation, a motor over-rotation prevention control unit that reduces the rotational speed of the motor by correcting the main power source rotational speed command value is included.

According to the motor overspeed prevention control device described in this publication, when it is determined that the motor rotation speed is excessive, the motor rotation speed is reduced by correcting the main power source rotation speed command value. As a result, when the motor rotation speed is predicted to over-rotate, over-rotation of the motor can be prevented in advance by correcting the rotational speed of the main power source.
JP 2004-153946 A

  By the way, due to the characteristics of the differential mechanism, when the rotational speed of one of the two rotating elements adjacent to the engine in the collinear diagram decreases, the other increases. Therefore, the rotational speed of the rotating electrical machine can be excessive even when the engine rotational speed does not change during the rapid deceleration of the vehicle. However, Japanese Patent Application Laid-Open No. 2004-153946 does not take into account any sudden deceleration of the vehicle.

  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 capable of preventing the rotational speed of a rotating electrical machine from becoming excessively large during sudden deceleration of a vehicle. And a control method, a program for realizing the method, and a recording medium on which the program is recorded.

  A control apparatus for a power train according to a first aspect of the present invention includes a first rotating element coupled to a rotating electrical machine, a second rotating element that transmits torque to a wheel, and a third rotating element coupled to an engine. A power train control device including a moving mechanism. The control device includes a means for detecting the rotation speed of the second rotation element, and the engine rotation speed when the decrease rate of the rotation speed of the second rotation element is larger than the threshold value and smaller than the threshold value. And control means for controlling to limit. The power train control method according to the sixth invention has the same requirements as those of the power train control device according to the first invention.

  According to the first or sixth invention, the rotational speed of the second rotating element that transmits torque to the wheel is detected. When the reduction rate of the rotation speed of the second rotation element is larger than the threshold value, the rotation speed of the engine is limited as compared with a case where the decrease rate is smaller. Since the first rotation element is one of the three rotation elements of the differential mechanism, the rotation speed of the first rotation element varies depending on the third rotation element, that is, the engine rotation speed. To do. Therefore, if the engine speed is limited, the speed of the first rotating element is limited. As a result, the rotational speed of the rotating electrical machine to which the first rotating element is connected can be prevented from becoming excessively large. Therefore, it is possible to provide a power train control device or control method capable of preventing the rotational speed of the rotating electrical machine from becoming excessively large during sudden deceleration of the vehicle.

  In addition to the configuration of the first invention, the power train control device according to the second invention further includes means for controlling the rotational speed of the rotating electrical machine to be equal to or lower than the first rotational speed. The control means includes means for controlling the rotational speed of the rotating electrical machine so as to limit the rotational speed of the engine by controlling the rotational speed of the rotating electrical machine to be equal to or lower than a second rotational speed smaller than the first rotational speed. 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 second invention.

  According to the second or seventh aspect of the invention, the rotational speed of the rotating electrical machine is controlled to be equal to or lower than the first rotational speed. When the rate of decrease in the rotational speed of the second rotating element is greater than the threshold value, the rotational speed of the rotating electrical machine is controlled to be equal to or lower than the second rotational speed that is smaller than the first rotational speed. The rotation speed is limited. As a result, the rotational speed of the rotating electrical machine to which the first rotating element is connected can be prevented from becoming excessively large.

  In the power train control device according to the third aspect of the invention, in addition to the configuration of the first aspect of the invention, the control means is means for controlling so as to limit the engine speed by stopping fuel injection in the engine. including. 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 third invention.

  According to the third or eighth invention, the engine speed is limited by stopping fuel injection in the engine. As a result, the rotational speed of the rotating electrical machine to which the first rotating element is connected can be prevented from becoming excessively large.

  In the power train control device according to the fourth aspect of the invention, in addition to the configuration of the first aspect, the control means controls to limit the engine speed by retarding the ignition timing in the engine. Including means. The power train control method according to the ninth aspect has the same requirements as those of the power train control apparatus according to the fourth aspect.

  According to the fourth or ninth invention, the engine speed is limited by retarding the ignition timing in the engine. As a result, the rotational speed of the rotating electrical machine to which the first rotating element is connected can be prevented from becoming excessively large.

  In the power train control device according to the fifth invention, in addition to the configuration of any one of the first to fourth inventions, the threshold value is made smaller as the rotational speed of the second rotating element is smaller. Determined. The power train control method according to the tenth invention has the same requirements as those of the power train control device according to the fifth invention.

  According to the fifth or tenth invention, in the differential mechanism, the rotation speed of the first rotation element can be increased as the rotation speed of the second rotation element is smaller. The threshold value to be compared with the number is determined to be smaller as the rotation number of the second rotation element is smaller. Thereby, it can be made easy to restrict | limit the engine speed, so that the rotation speed of a 1st rotation element is large. Therefore, it is possible to prevent the rotational speed of the rotating electrical machine from becoming excessively large when the vehicle is suddenly decelerated.

  A program according to an eleventh invention is a program for causing a computer to implement the control method according to any of the sixth to tenth inventions, and the recording medium according to the twelfth invention is any one of the sixth to tenth inventions 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 eleventh or twelfth invention, the power train control method according to any of the sixth to tenth inventions can be realized 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.

<First Embodiment>
With reference to FIG. 1, a description will be given of a hybrid vehicle equipped with a control device according to a first embodiment of the present invention. 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.

  ECU 800 may be divided into a plurality of ECUs. Further, a program executed by the 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.

  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 stroke 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, the oil temperature sensor 826, and the water temperature sensor 828 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.

  Accelerator opening sensor 810 detects the opening of accelerator pedal 808 and transmits a signal representing the detection result to ECU 800. The stroke sensor 814 detects the operation amount of the brake pedal 812 (the amount by 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.

  Water temperature sensor 828 detects the temperature (water temperature) of cooling water for engine 200 and transmits a signal representing the detection result to ECU 800.

  The ECU 800 includes a position switch 806, an accelerator opening sensor 810, a stroke sensor 814, a throttle opening sensor 818, an engine speed sensor 820, an input shaft speed sensor 822, an output shaft speed sensor 824, an oil temperature sensor 826, and a water temperature sensor. Based on the signal sent from 828 or the like, 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. Torque of ring gear 328 is transmitted to rear wheel 700.

  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.

  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 a broken line in FIG. 3, if the engine speed NE does not decrease when the rotation speed of the second MG 312 decreases, the rotation speed of the first MG 311 increases.

  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, rotational speed NR of ring gear 328 are the same.

  The automatic transmission 400 includes a single pinion type first planetary gear (P1) 410 and a second planetary gear (P2) 420, and five frictional engagements including a C1 clutch 431, a C2 clutch 432, a C3 clutch 433, a B1 brake 441, and a B2 brake 442. And a combination element.

  Further, automatic transmission 400 includes one-way clutch (F) 450. One-way clutch (F) 450 allows relative rotation of inner race 452 and outer race 454 in one direction and restricts the reverse direction. In the present embodiment, the engaged state of the one-way clutch (F) 450 means a state where relative rotation between the inner race 452 and the outer race 454 is restricted.

  First planetary gear (P1) 410 includes a sun gear (S1) 412, a carrier (CA1) 414, and a ring gear (R1) 416. The sun gear (S1) 412 is connected to the input shaft 404 by the engagement of the C3 clutch 433. The sun gear (S1) 412 is fixed to the case 402 by the engagement of the B1 brake 441.

  The carrier (CA1) 414 is connected to the input shaft 404 by engagement of the C2 clutch 432. The carrier (CA1) 414 is fixed to the case 402 by the engagement of the B2 brake 442 or the one-way clutch (F) 450. Ring gear (R 1) 416 is coupled to output shaft 406.

  Second planetary gear (P2) 420 includes a sun gear (S2) 422, a carrier (CA2) 424, and a ring gear (R2) 426. The sun gear (S2) 422 is connected to the input shaft 404 by engagement of the C1 clutch 431.

  The carrier (CA2) 424 is coupled to the output shaft 406. Ring gear (R2) 426 is coupled to carrier (CA1) 414 of first planetary gear (P1) 410. Therefore, the ring gear (R2) 426 is fixed to the case 402 by the engagement of the B2 brake 442 or the one-way clutch (F) 450.

  A desired gear stage is formed in the automatic transmission 400 by engaging the friction engagement elements of the automatic transmission 400 in a predetermined combination.

  In the present embodiment, when the vehicle is driven (running with the driving force of the drive source), the first gear is formed by engagement of C1 clutch 431 and one-way clutch (F) 450. When the vehicle is driven, a first gear is formed by engagement of the C1 clutch 431 and the B2 brake 442.

  The engagement of the C1 clutch 431 and the B1 brake 441 forms a second gear. The engagement of the C1 clutch 431 and the C2 clutch 432 forms a third gear. Shifting in automatic transmission 400 is performed based on, for example, a shift diagram.

  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.

  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.

  The C1 clutch 431, the C2 clutch 432, the C3 clutch 433, the B1 brake 441 and the B2 brake 442 are operated by hydraulic pressure. In the present embodiment, as shown in FIG. 4, the hybrid vehicle is provided with a hydraulic control device 900 that supplies / discharges hydraulic pressure to / 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 case 402. 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 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. 5, 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 ring gear rotation speed detection unit 840, a rapid deceleration determination unit 842, a first control unit 844, and a second control unit 846.

  Ring gear rotation speed detector 840 detects the input shaft rotation speed of automatic transmission 400, that is, the rotation speed NR of ring gear 328 of power split mechanism 310, based on the signal transmitted from input shaft rotation speed sensor 822.

  The sudden deceleration determination unit 842 determines whether or not the vehicle speed has rapidly decreased. As shown in FIG. 6, when the reduction rate of the rotational speed NR of the ring gear 328 is larger than the threshold value that is set to be smaller as the rotational speed NR of the ring gear 328 is smaller, it is determined that the vehicle speed has rapidly decreased. .

  First control unit 844 executes normal control related to the rotational speed of first MG 311. In the normal control, as shown in FIG. 7, first MG 311, second MG 312, and engine 200 are controlled such that the rotation speed of first MG 311 is not less than lower limit value NSL (1) and not more than upper limit value NSH (1). Further, the first MG 311, the second MG 312 and the difference between the rotational speed NR of the ring gear 328 and the rotational speed of the carrier 326, that is, the relative rotational speed PIN is not less than the lower limit value PINL (1) and not more than the upper limit value PINH (1). The engine 200 is controlled.

  When it is determined that the vehicle speed has suddenly decreased, that is, when the rate of decrease in rotational speed NR of ring gear 328 is greater than the threshold value, second control unit 846 performs a process of limiting the load factor (intake air amount) of engine 200. To do.

  In the load factor limiting process, as shown in FIG. 8, the first MG 311, the second MG 312 and the engine 200 are controlled so that the rotation speed of the first MG 311 is not less than the lower limit value NSL (2) and not more than the upper limit value NSH (2). Is done. Further, the first MG 311, the second MG 312, and the engine 200 are set so that the relative rotational speed PIN between the rotational speed NR of the ring gear 328 and the rotational speed of the carrier 326 is not less than the lower limit value PINL (2) and not more than the upper limit value PINH (2). Be controlled.

  Lower limit value NSL (2) of the rotation speed of first MG 311 is larger than lower limit value NSL (1). Upper limit value NSH (2) of the rotation speed of first MG 311 is smaller than upper limit value NSH (1). Similarly, the lower limit value PINL (2) of the relative rotational speed PIN is larger than the lower limit value PINL (1). The upper limit value PINH (2) of the relative rotational speed PIN is smaller than the upper limit value PINH (1).

  Further, in the load factor limiting process, as shown in FIG. 9, the load factor of engine 200, that is, the intake air, is set to be equal to or lower than upper limit value KLH that is set to be smaller as rotation speed NR of ring gear 328 is larger. The amount is controlled.

  That is, the rotational speed of the first MG 311 is equal to or lower than the upper limit value NSH (2), and the relative rotational speed PIN between the rotational speed NR of the ring gear 328 and the rotational speed of the carrier 326 is equal to or lower than the upper limit value PINH (2). The load factor of engine 200 is limited to upper limit value KLH or less. Therefore, when the reduction rate of the rotational speed NR of the ring gear 328 is larger than the threshold value, the rotational speed of the engine 200 is limited as compared with the case where it is smaller.

  With reference to FIG. 10, 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 detects the accelerator opening based on the signal transmitted from accelerator opening sensor 810. In S110, ECU 800 detects the stroke amount of brake pedal 812 based on the signal transmitted from stroke sensor 814.

  In S120, ECU 800 detects the input shaft rotational speed of automatic transmission 400, that is, the rotational speed NR of ring gear 328 of power split mechanism 310, based on the signal transmitted from input shaft rotational speed sensor 822.

  In S130, ECU 800 determines whether both the accelerator operation and the brake operation have been performed and the vehicle speed has rapidly decreased. For example, if the accelerator opening is equal to or greater than a threshold value, it is determined that an accelerator operation has been performed. Similarly, if the stroke amount of the brake pedal 812 is equal to or greater than the threshold value, it is determined that the brake operation has been performed.

  If the accelerator operation and the brake operation are both performed and the vehicle speed decreases rapidly (YES in S130), the process proceeds to S140. If not (NO in S130), the process proceeds to S150.

  In S140, ECU 800 executes a limiting process for setting the load factor of engine 200 to the upper limit value KLH or less. That is, ECU 800 has relative rotation speed PIN between rotation speed NR of ring gear 328 and rotation speed of carrier 326 such that the rotation speed of first MG 311 is not less than lower limit value NSL (2) and not more than upper limit value NSH (2). Controls the first MG 311, the second MG 312, and the engine 200 so that the value becomes lower than the lower limit value PINL (2) and lower than the upper limit value PINH (2).

  In S150, ECU 800 executes normal control regarding the rotational speed of first MG 311. That is, ECU 800 has relative rotation speed PIN between rotation speed NR of ring gear 328 and rotation speed of carrier 326 so that the rotation speed of first MG 311 is not less than lower limit value NSL (1) and not more than upper limit value NSH (1). Controls the first MG 311, the second MG 312, and the engine 200 so that the lower limit value PINL (1) is equal to or greater than the upper limit value PINH (1).

  A control structure of a program executed by ECU 800, which is the control device according to the present embodiment, based on the above-described structure and flowchart will be described.

  While the vehicle is running, the accelerator opening is detected (S100), and the stroke amount of the brake pedal 812 is detected (S110). Further, the input shaft rotation speed of automatic transmission 400, that is, rotation speed NR of ring gear 328 of power split device 310 is detected (S120).

  If at least one of the accelerator operation and the brake operation has not been performed, or the vehicle speed has not decreased rapidly (NO in S130), normal control is executed with respect to the rotation speed of first MG 311.

  That is, the rotation speed of first MG 311 is not less than lower limit value NSL (1) and not more than upper limit value NSH (1), and relative rotation speed PIN between rotation speed NR of ring gear 328 and rotation speed of carrier 326 is the lower limit value. First MG 311, second MG 312, and engine 200 are controlled so as to be equal to or greater than PINL (1) and equal to or less than upper limit value PINH (1) (S 150).

  By the way, when the vehicle speed, that is, the rotation speed of the ring gear 328 rapidly decreases without the engine rotation speed NE decreasing, the rotation speed of the first MG 311 increases rapidly as indicated by a broken line in FIG. Therefore, the generated power value of the first MG 311 can increase rapidly. When the generated power value of the first MG 311 becomes larger than necessary, the electric system in the hybrid vehicle may be adversely affected. Therefore, the generated power value of first MG 311 is limited. By limiting the generated power value of the first MG 311, the torque in the direction of reducing the rotational speed of the first MG 311 is reduced. As a result, the rotation speed of the first MG 311 can be further increased until it becomes excessive.

  Therefore, if both the accelerator operation and the brake operation are performed and the vehicle speed decreases rapidly (YES in S130), that is, if the rotation speed of ring gear 328 decreases rapidly without decreasing engine rotation speed NE, the load factor of engine 200 is increased to the upper limit. A restriction process is performed to make the value KLH or less (S140).

  That is, the rotation speed of first MG 311 is not less than lower limit value NSL (2) and not more than upper limit value NSH (2), and relative rotation speed PIN between rotation speed NR of ring gear 328 and the rotation speed of carrier 326 is the lower limit value. First MG 311, second MG 312, and engine 200 are controlled so as to be equal to or greater than PINL (2) and equal to or less than upper limit value PINH (2).

  Thereby, when the load factor of engine 200 has already exceeded upper limit value KLH, the amount of intake air can be reduced by reducing the throttle opening of throttle valve 816, for example. Therefore, as indicated by the alternate long and short dash line in FIG. 11, the engine speed NE can be reduced. As a result, the rotational speed of the first MG 311 can be reduced so that it does not become excessive.

  Further, when the load factor of engine 200 is equal to or lower than upper limit value KLH, the load factor of engine 200 can be prevented from exceeding upper limit value KLH. Therefore, the load factor of engine 200 can be limited early so that the rotation speed of first MG 311 does not become excessive.

  As described above, according to the ECU that is the control device according to the present embodiment, when the vehicle speed, that is, the rotation speed of the ring gear of the power split mechanism, rapidly decreases, the engine load factor limiting process is executed. In the load factor control process, the rotation speed of the first MG is less than or equal to the upper limit value NSH (2), and the relative rotation speed PIN between the rotation speed NR of the ring gear and the rotation speed of the carrier is less than or equal to the upper limit value PINH (2). Thus, the engine load factor is limited to the upper limit value KLH or less. Thereby, the engine speed NE can be limited. Therefore, the rotation speed of the first MG can be prevented from becoming excessive.

<Second Embodiment>
Hereinafter, a second embodiment of the present invention will be described. The present embodiment is different from the first embodiment in that the engine speed NE is limited by executing fuel cut (stopping fuel injection in the engine 200). Other structures are the same as those in the first embodiment. The function about them is the same. Therefore, detailed description thereof will not be repeated here.

  With reference to FIG. 12, the function of ECU 800 serving as the control device according to the present embodiment will be described. In addition, the same number is attached | subjected about the same function as the function in the above-mentioned 1st Embodiment. Therefore, description thereof will not be repeated here.

  ECU 800 includes a fuel cut unit 850 in addition to ring gear rotation speed detection unit 840 and rapid deceleration determination unit 842. When it is determined that the vehicle speed has suddenly decreased, that is, when the rate of decrease in the rotational speed NR of the ring gear 328 is greater than the threshold value, the fuel cut unit 850 executes fuel cut to limit the engine rotational speed NE. By executing the fuel cut, the fuel injection from the injector 202 is stopped, and the engine speed NE is reduced.

  With reference to FIG. 13, a control structure of a program executed by ECU 800 serving as the control apparatus according to the present embodiment will be described. Note that the program described below is repeatedly executed at a predetermined cycle. The same step numbers are assigned to the same processes as those in the first embodiment. Therefore, detailed description thereof will not be repeated here.

  In S200, ECU 800 executes fuel cut. Even if it does in this way, there can exist an effect similar to the above-mentioned 1st Embodiment.

<Third Embodiment>
Hereinafter, a third embodiment of the present invention will be described. The present embodiment differs from the first embodiment described above in that the engine speed NE is limited by retarding the ignition timing in the engine 200. Other structures are the same as those in the first embodiment. The function about them is the same. Therefore, detailed description thereof will not be repeated here.

  With reference to FIG. 14, the function of ECU 800 serving as the control apparatus according to the present embodiment will be described. In addition, the same number is attached | subjected about the same function as the function in the above-mentioned 1st Embodiment. Therefore, description thereof will not be repeated here.

  ECU 800 includes a retard angle portion 860 in addition to ring gear rotation speed detection portion 840 and sudden deceleration determination portion 842. When it is determined that the vehicle speed has suddenly decreased, that is, when the rate of decrease in the rotational speed NR of the ring gear 328 is greater than the threshold value, the retard portion 860 sets the ignition timing in the engine 200 in order to limit the engine rotational speed NE. Be retarded. By retarding the ignition timing, the output of the engine 200 decreases, and the engine speed NE decreases.

  With reference to FIG. 15, a control structure of a program executed by ECU 800 serving as the control apparatus according to the present embodiment will be described. Note that the program described below is repeatedly executed at a predetermined cycle. The same step numbers are assigned to the same processes as those in the first embodiment. Therefore, detailed description thereof will not be repeated here.

  In S300, ECU 800 retards the ignition timing. Even if it does in this way, there can exist an effect similar to the above-mentioned 1st Embodiment.

  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 ECU which is a control apparatus which concerns on embodiment of this invention. It is a figure 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 a hydraulic control apparatus. It is a functional block diagram of ECU which is a control device concerning a 1st embodiment of the present invention. It is a figure which shows the threshold value determined from the rotational speed NS of a ring gear, and the decreasing rate of the rotational speed NS of a ring gear. It is FIG. (The 1) which shows the lower limit of the rotation speed of MG1, an upper limit, etc. FIG. It is a figure (the 2) which shows the lower limit of the rotation speed of MG1, an upper limit, etc. FIG. It is a figure which shows the upper limit KLH of a load factor. It is a flowchart which shows the control structure of the program which ECU which is a control apparatus which concerns on the 1st Embodiment of this invention performs. FIG. 8 is a second diagram showing a nomographic chart of the power split mechanism. It is a functional block diagram of ECU which is a control apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the control structure of the program which ECU which is a control apparatus which concerns on the 2nd Embodiment of this invention performs. It is a functional block diagram of ECU which is a control apparatus which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the control structure of the program which ECU which is a control apparatus which concerns on the 3rd Embodiment of this invention performs.

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, 404 input shaft, 406 output shaft, 431 C1 clutch 432 C2 clutch, 433 C3 clutch, 441 B1 brake, 442 B2 brake, 450 one-way clutch (F), 800 ECU, 802 ROM, 804 shift lever, 806 position switch, 808 accelerator pedal, 810 accelerator opening sensor, 812 brake Pedal, 814 stroke sensor, 816 electronic throttle valve, 818 throttle opening sensor, 820 engine Rotational speed sensor, 822 Input shaft rotational speed sensor, 824 Output shaft rotational speed sensor, 826 Oil temperature sensor, 828 Water temperature sensor, 830 Rotational speed sensor, 832 Hydraulic pressure sensor, 840 Ring gear rotational speed detection section, 842 Rapid deceleration determination section, 844 1st control part, 846 2nd control part, 850 Fuel cut part, 860 Retardation part.

Claims (12)

A power train control device including a differential mechanism having a first rotating element coupled to a rotating electrical machine, a second rotating element transmitting torque to a wheel, and a third rotating element coupled to an engine. ,
Means for detecting the rotational speed of the second rotating element;
A control device for controlling the power train, comprising: a control means for controlling the engine speed to be limited when the rate of decrease in the engine speed of the second rotating element is greater than a threshold value when compared with a smaller value. . The control device further includes means for controlling the rotational speed of the rotating electrical machine to be equal to or lower than a first rotational speed,
The control means controls the engine speed to be limited by controlling the rotation speed of the rotating electrical machine to be equal to or less than a second rotation speed smaller than the first rotation speed. The control apparatus of the power train of Claim 1 containing a means.   2. The power train control device according to claim 1, wherein the control means includes means for controlling to limit a rotational speed of the engine by stopping fuel injection in the engine. 3.   2. The power train control device according to claim 1, wherein the control means includes means for controlling so as to limit a rotational speed of the engine by retarding an ignition timing in the engine. 3.   5. The power train control device according to claim 1, wherein the threshold value is set to be smaller as the rotational speed of the second rotating element is smaller. A power train control method comprising a differential mechanism having a first rotating element coupled to a rotating electrical machine, a second rotating element transmitting torque to a wheel, and a third rotating element coupled to an engine. ,
Detecting the number of revolutions of the second rotating element;
And a control method for controlling the engine speed to limit the engine speed when the rate of decrease in the rotational speed of the second rotating element is greater than a threshold value, compared to when it is smaller. The control method further includes a step of controlling the rotational speed of the rotating electrical machine to be equal to or lower than a first rotational speed,
The step of controlling the rotational speed of the engine to limit the rotational speed of the engine by controlling the rotational speed of the rotating electrical machine to be equal to or less than a second rotational speed that is smaller than the first rotational speed. The power train control method according to claim 6, comprising a step of controlling the number to be limited.   The power train according to claim 6, wherein the step of controlling to limit the rotational speed of the engine includes the step of controlling to limit the rotational speed of the engine by stopping fuel injection in the engine. Control method.   The power train according to claim 6, wherein the step of controlling to limit the engine speed includes a step of controlling to limit the engine speed by retarding an ignition timing in the engine. Control method.   10. The power train control method according to claim 6, wherein the threshold value is set to be smaller as the rotational speed of the second rotating element is smaller. 11.   The program which makes a computer implement | achieve the control method in any one of Claims 6-10.   The computer-readable recording medium which recorded the program which makes a computer implement | achieve the control method in any one of Claims 6-10.

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