Power output apparatus, hybrid vehicle with the same, and method for controlling power output apparatus

A hybrid vehicle including drive wheels driven by power from a drive shaft, said hybrid vehicle comprising:

• an internal combustion engine;
• a first motor capable of inputting and outputting power;
• a second motor capable of inputting and outputting power;
• an accumulator capable of supplying and receiving power to and from each of said first and second motors;
• a power distribution and integration mechanism having a first element connected to a rotating shaft of said first motor, a second element connected to a rotating shaft of said second motor, and a third element connected to an engine shaft of said internal combustion engine, said power distribution and integration mechanism being configured so that these three elements can be differentially rotated with respect to each other;
• a connection/disconnection device capable of performing a drive source element connection and a release of said drive source element connection which is one of a connection between said first motor and said first element, a connection between said second motor and said second element, and a connection between said internal combustion engine and said third element;
• a speed change-transmission assembly capable of selectively coupling one of or both of said rotating shaft of said first motor and said rotating shaft of said second motor to said drive shaft, said speed change-transmission assembly being capable of transmitting power from said first motor and power from said second motor to said drive shaft at predetermined respective speed ratios;
• a power demand setting device for setting power demand which is power required for said drive shaft;
• and
• a control device for controlling said first motor, said second motor, and said connection/disconnection device, so that power based on said set power demand is output to said drive shaft, said control device, when an engine start condition for starting said internal combustion engine is satisfied in a state in which said drive source element connection is released, said internal combustion engine is stopped, only one of said first and second motors is coupled to said drive shaft by said speed change-transmission assembly, and said one of said first and second motors outputs power, controlling said first motor, said second motor, and said connection/disconnection device with a rotation speed adjusting process of adjusting a rotation speed of the other of said first and second motors so as to enable said drive source element connection, said drive source element connection, and an engine start process of cranking said internal combustion engine by said first or second motor.

A power output apparatus for outputting power to a drive shaft, said power output apparatus comprising:

• an internal combustion engine;
• a first motor capable of inputting and outputting power;
• a second motor capable of inputting and outputting power;
• an accumulator capable of supplying and receiving power to and from each of said first and second motors;
• a power distribution and integration mechanism having a first element connected to a rotating shaft of said first motor, a second element connected to a rotating shaft of said second motor, and a third element connected to an engine shaft of said internal combustion engine, said power distribution and integration mechanism being configured so that these three elements can be differentially rotated with respect to each other;
• a connection/disconnection device disposed between said first motor and said first element or between said second motor and said second element, said connection/disconnection device being capable of performing a connection and a release of said connection between said rotating shaft of said first or second motor and said first or second element;
• and
• a speed change-transmission assembly capable of selectively coupling said rotating shaft of said first or second motor corresponding to said connection/disconnection device and said first or second element not corresponding to said connection/disconnection device to said drive shaft, said speed change-transmission assembly being capable of transmitting power from a rotating shaft of said first or second motor and power from said first or second element to said drive shaft at predetermined respective speed ratios.

A method of controlling a power output apparatus including a drive shaft;

• an internal combustion engine;
• a first motor and a second motor capable of inputting and outputting power respectively;
• an accumulator capable of supplying and receiving power to and from each of said first and second motors;
• a power distribution and integration mechanism having a first element connected to a rotating shaft of said first motor, a second element connected to a rotating shaft of said second motor, and a third element connected to an engine shaft of said internal combustion engine and configured so that these three elements can be differentially rotated with respect to each other;
• a connection/disconnection device capable of performing a drive source element connection and a release of said drive source element connection which is one of a connection between said first motor and said first element, a connection between said second motor and said second element, and a connection between said internal combustion engine and said third element;
• a speed change-transmission assembly capable of selectively coupling one of or both of said rotating shaft of said first motor and said rotating shaft of said second motor to said drive shaft, said speed change-transmission assembly being capable of transmitting power from said first motor and power from said second motor to said drive shaft at predetermined respective speed ratios;
• said control method comprising:
• (a) adjusting, when an engine start condition for starting said internal combustion engine is satisfied in a state in which said drive source element connection is released, said internal combustion engine is stopped, only one of said first and second motors is coupled to said drive shaft by said speed change-transmission assembly, and said one of said first and second motors outputs power, a rotation speed of the other of said first and second motors so as to enable said drive source element connection;
• (b) performing said drive source element connection;
• and
• (c) starting said internal combustion engine with cranking by said first or second motor.