초록 ▼

A control system provided in a hybrid vehicle with a combustion engine for outputting a driving force, an electric motor for generating a force for assisting the output from the engine, depending on driving conditions, a power storage unit for storing electric energy generated by the motor acting as

A control system provided in a hybrid vehicle with a combustion engine for outputting a driving force, an electric motor for generating a force for assisting the output from the engine, depending on driving conditions, a power storage unit for storing electric energy generated by the motor acting as a generator using the output from the engine and electric energy regenerated by the motor when the vehicle decelerates. The control system includes an output assist determination means for determining, based on a determination threshold value as the standard, whether to assist the output from the engine by the motor, depending on the driving conditions of the vehicle. An air-fuel controller is provided for changing the air-fuel ratio of the mixture, which is to be supplied to the engine, to a condition leaner or richer than the stoichiometric air-fuel ratio. A determination threshold value changing means is provided for changing the determination threshold value, depending on whether the air-fuel ratio of the mixture is leaner or richer than the stoichiometric air-fuel ratio. A determination threshold value change prohibiting means is provided for prohibiting the operation of the determination threshold value changer when the air-fuel controller changes the air-fuel ratio of the mixture from a condition leaner than the stoichiometric air-fuel ratio to a condition richer than the stoichiometric air-fuel ratio.

대표청구항 ▼

A control system provided in a hybrid vehicle with a combustion engine for outputting a driving force, an electric motor for generating a force for assisting the output from the engine, depending on driving conditions, a power storage unit for storing electric energy generated by the motor acting as

A control system provided in a hybrid vehicle with a combustion engine for outputting a driving force, an electric motor for generating a force for assisting the output from the engine, depending on driving conditions, a power storage unit for storing electric energy generated by the motor acting as a generator using the output from the engine and electric energy regenerated by the motor when the vehicle decelerates. The control system includes an output assist determination means for determining, based on a determination threshold value as the standard, whether to assist the output from the engine by the motor, depending on the driving conditions of the vehicle. An air-fuel controller is provided for changing the air-fuel ratio of the mixture, which is to be supplied to the engine, to a condition leaner or richer than the stoichiometric air-fuel ratio. A determination threshold value changing means is provided for changing the determination threshold value, depending on whether the air-fuel ratio of the mixture is leaner or richer than the stoichiometric air-fuel ratio. A determination threshold value change prohibiting means is provided for prohibiting the operation of the determination threshold value changer when the air-fuel controller changes the air-fuel ratio of the mixture from a condition leaner than the stoichiometric air-fuel ratio to a condition richer than the stoichiometric air-fuel ratio. wherein the distribution of the impurities of first conductivity type increases from the junction toward the trench. 19. The high breakdown voltage vertical semiconductor device according to claim 16, wherein the graded junction comprises a one-sided abrupt junction. 20. A high breakdown voltage vertical semiconductor device, comprising: a semiconductor substrate; a structural section in which a first semiconductor region of first conductivity type and a second semiconductor region of second conductivity type are arranged alternately, the structural section being formed on the semiconductor substrate; a semiconductor layer of second conductivity type being formed on the structural section; a second trench provided in a semiconductor layer of second conductivity type; a buried gate electrode being formed in the second trench intervening a gate insulating film; a first trench which extends to the semiconductor substrate through the buried gate electrode, the gate insulating film and the first semiconductor region; an insulating film being formed in the first trench; a third semiconductor region of first conductivity type being formed in the semiconductor substrate; and a fourth semiconductor region of first conductivity type being formed in the semiconductor layer of second conductivity type adjacent to the gate insulating film, wherein a graded junction is formed between the first semiconductor region and the second semiconductor region, and wherein an impurity profile of first conductivity type in the graded junction is graded along a direction in which the first and second semiconductor regions are arranged alternately. 21. The high breakdown voltage vertical semiconductor device according to claim 20, wherein the distribution of the impurities of first conductivity type in the graded junction decreases toward a junction between the first semiconductor region and the second semiconductor region. 22. The high breakdown voltage vertical semiconductor device according to claim 21, wherein the distribution of the impurities of first conductivity type increases from the junction toward the first trench. 23. The high breakdown voltage vertical semiconductor device according to claim 20, wherein the graded junction comprises a one-sided abrupt junction. 24. A high breakdown voltage vertical semiconductor device, comprising: a semiconductor substrate; a structural section in which a first semiconductor region of first conductivity type and a second semiconductor region of second conductivity type are arranged alternately, the structural section being formed on the semiconductor sub