Control apparatus and control method for hybrid vehicle

#The disclosure of Japanese Patent Application No. 2012-281165, filed on Dec. 25, 2012 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

#1. Field of the Invention

#The invention relates to a control apparatus and a control method applied to a hybrid vehicle having an engine and a motor generator as travel power sources.

#Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

#FIG. 1 is a view showing an overall configuration of a vehicle to which a control apparatus according to a first embodiment of the invention is applied;

#FIG. 2 is a view illustrating an operating point of an engine during an all-cylinder operation and a partial cylinder operation, according to the first embodiment;

#As shown in FIG. 1, a vehicle 1 is constituted as a hybrid vehicle in which a plurality of power sources are combined. The vehicle 1 includes, as power sources for traveling, an engine 3 and two motor generators 4, 5. The engine 3 is constituted as an inline four-cylinder internal combustion engine having four cylinders 10. The engine 3 is configured to execute an all-cylinder operation, in which all of the four cylinders 10 are operated, and a partial cylinder operation, in which two of the four cylinders 10 are rested and the remaining two cylinders are operated.

#The engine 3 and the first motor generator 4 are coupled to a power distribution mechanism 6 serving as a differential mechanism. The first motor generator 4 includes a stator 4a and a rotor 4b. The first motor generator 4 functions as both a power generator that generates power upon reception of power from the engine 3 distributed thereto by the power distribution mechanism 6, and a motor driven by alternating current power. Similarly, the second motor generator 5 includes a stator 5a and a rotor 5b, and functions as both a power generator and a motor. The respective motor generators 4, 5 are connected to a battery 16 via a motor control apparatus 15. The motor control apparatus 15 converts the power generated by the respective motor generators 4, 5 into direct current power to be stored in the battery 16, and converts power from the battery 16 into alternating current power to be supplied to the motor generators 4, 5. The first motor generator 4 may be regarded as a motor generator according to the invention.

#The power distribution mechanism 6 is constituted as a single pinion type planetary gear mechanism. The power distribution mechanism 6 includes a sun gear S of an external gear, a ring gear R of an internal gear, which is disposed coaxially with the sun gear S, and a planetary carrier C holding a pinion P that meshes with the gears S, R to be capable of rotating and revolving. An engine torque output by the engine 3 is transmitted to the planetary carrier C of the power distribution mechanism 6. The rotor 4b of the first motor generator 4 is coupled to the sun gear S of the power distribution mechanism 6. Torque output from the power distribution mechanism 6 via the ring gear R is transmitted to an output gear train 20. The output gear train 20 functions as an output portion for transmitting torque to drive wheels 18. The output gear train 20 includes an output drive gear 21 that rotates integrally with the ring gear R of the power distribution mechanism 6, and an output driven gear 22 that meshes with the output drive gear 21. The second motor generator 5 is coupled to the output driven gear 22 via a gear 23. The gear 23 rotates integrally with the rotor 5b of the second motor generator 5. Torque output from the output driven gear 22 is distributed to the left and right drive wheels 18 via a differential apparatus 24.