Power output apparatus and control method for same
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsMasaki Kusada, Katsuhiko Yamaguchi, Toshio Inoue
Life of this patent
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Abstract
During the catalyst warm-up period, when control enabling reduction in hydrocarbons is not executed in gasoline engine 100, the opening of the throttle valve 101 is made smaller in order to reduce the hydrocarbon discharge. During the catalyst warm-up period, when control enabling reduction in the quantity of hydrocarbons is executed in gasoline engine 100, the opening of the throttle valve 101 is made larger in order to accelerate warm-up of the catalyst, thereby shortening the catalyst warm-up period. A shorter catalyst warm-up period enables reduction in the total quantity of hydrocarbons from engine startup to the end of the catalyst warm-up period.
Claims24
A power output apparatus comprising:
- an engine that outputs power to a drive shaft;
- an air flow rate adjustment mechanism that adjusts an air flow rate supplied to the engine;
- an exhaust system having a catalyst, for discharging exhaust gas from the engine;
- a first suppression controller that, after startup of the engine, controls the air flow rate adjustment mechanism so as to limit the air flow rate to a level equal to or less than a predetermined flow rate;
- and
- a second suppression controller that, at a predetermined timing, transitions an operation of the engine to a reduced hydrocarbon operation state established so as to reduce a quantity of hydrocarbons within the exhaust gas, and cancels the limit on the air flow rate, wherein the air flow rate during a control of the first suppression controller is less than the air flow rate during a control of the second compression controller.
A power output apparatus comprising:
- an engine that outputs power to a drive shaft;
- an air flow rate adjustment mechanism that adjusts an air flow rate supplied to the engine;
- an exhaust system that discharges exhaust gas from the engine;
- a catalyst disposed in the exhaust system;
- a normal controller that performs normal operation of the engine when the catalyst has been activated;
- a first hydrocarbon suppression controller that, when the catalyst has not been activated, controls operation of the engine so as to reduce a concentration of hydrocarbons within the exhaust gas to an amount less than that during normal operation, before passage through the catalyst;
- and
- a second hydrocarbon suppression controller that, during at least a predetermined period after startup of the engine, prohibits operation of the first hydrocarbon suppression controller, and controls the air flow rate adjustment mechanism so as to reduce the air flow rate to a value equal to or less than a predetermined value, wherein the air flow rate during a control of the first hydrocarbon suppression controller is greater than the air flow rate during a control of the second hydrocarbon suppression controller.
A method of controlling a power output apparatus, the power output apparatus comprising an engine that outputs power to a drive shaft, an air flow rate adjustment mechanism that adjusts the air flow rate supplied to the engine, and an exhaust system having a catalyst for discharging exhaust gas from the engine, the method comprising:
- performing a first suppression control wherein, after startup of the engine, the air flow rate adjustment mechanism is controlled so as to limit the air flow rate to a level equal to or less than a predetermined flow rate;
- and
- performing a second suppression control wherein, at a predetermined timing, an operation of the engine is transitioned to a reduced hydrocarbon operation state established so as to reduce a quantity of hydrocarbons within the exhaust gas;
- and the limit on the air flow rate is cancelled, wherein the air flow rate during the first suppression control is less than the air flow rate during the second suppression control.
A method of controlling a power output apparatus, the power output apparatus comprising an engine that outputs power to a drive shaft, an air flow rate adjustment mechanism that adjusts the air flow rate supplied to the engine, and an exhaust system having a catalyst for discharging exhaust gas from the engine, the method comprising:
- performing a normal control wherein the engine is operated normally after the catalyst has been activated;
- performing a first hydrocarbon suppression control wherein, when the catalyst has not been activated, operation of the engine is controlled so as to reduce a concentration of hydrocarbons within the exhaust gas to an amount less than that during normal operation, before passage through the catalyst;
- and
- performing a second hydrocarbon suppression control wherein, during at least a predetermined period after startup of the engine, operation of the first hydrocarbon suppression control step is prohibited, and the air flow rate adjustment mechanism is controlled so as to reduce the air flow rate to a value equal to or less than a predetermined value, wherein the air flow rate during the first hydrocarbon suppression control is greater than the air flow rate during the second hydrocarbon suppression control.
Dependencies are inferred from the claim text.