Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
155 words
A hybrid vehicle driving system comprising: an internal-combustion engine capable of selectively operating in a first operating mode in which a fuel mixture having an air-fuel ratio not lower than a first predetermined value is supplied to the internal-combustion engine, and a second operating mode in which a fuel mixture having an air-fuel ratio not higher than a second predetermined value, which is smaller than the first predetermined value is supplied to the internal-combustion engine; an electric motor; and a transmission for producing a composite torque by combining an output torque of the internal-combustion engine and an output torque of the electric motor and transmitting the composite torque to driving wheels; wherein the electric motor produces a torque that is applied to reduce the size of step increases or decreases in the output torque of the internal-combustion engine which occurs when the internal-combustion engine changes between the first operating mode and the second operating mode.
Claim 2
Dependent Claim
155 words
A hybrid vehicle driving system comprising: an internal-combustion engine capable of selectively operating in a first operating mode in which a fuel mixture having an air-fuel ratio not lower than a first predetermined value is supplied to the internal-combustion engine, and a second operating mode in which a fuel mixture having an air-fuel ratio not higher than a second predetermined value, which is smaller than the first predetermined value is supplied to the internal-combustion engine; an electric motor; and a transmission for producing a composite torque by combining an output torque of the internal-combustion engine and an output torque of the electric motor and transmitting the composite torque to driving wheels; wherein the electric motor produces a torque that is applied to reduce the size of step increases or decreases in the output torque of the internal-combustion engine which occurs when the internal-combustion engine changes between the first operating mode and the second operating mode.
Claim 3
Dependent Claim
144 words
A hybrid vehicle driving method comprising: operating an internal-combustion engine selectively in a first operating mode in which a mixture of an air-fuel ratio not lower than a first predetermined value is supplied to the internal-combustion engine, and a second operating mode in which a mixture of an air-fuel ratio not higher than a second predetermined value, which is smaller than the first predetermined value is supplied to the internal combustion engine; combining respective output torques of the internal-combustion engine and an electric motor to generate a composite torque; and applying the combined torque to drive wheels of said vehicle; wherein the electric motor is driven and the air-fuel ratio of the mixture supplied to the internal-combustion engine is maintained at the first value when the air-fuel ratio decreases below the first value while the internal-combustion engine is operating in the first operating mode.
Claim 4
Dependent Claim
144 words
A hybrid vehicle driving method comprising: operating an internal-combustion engine selectively in a first operating mode in which a mixture of an air-fuel ratio not lower than a first predetermined value is supplied to the internal-combustion engine, and a second operating mode in which a mixture of an air-fuel ratio not higher than a second predetermined value, which is smaller than the first predetermined value is supplied to the internal combustion engine; combining respective output torques of the internal-combustion engine and an electric motor to generate a composite torque; and applying the combined torque to drive wheels of said vehicle; wherein the electric motor is driven and the air-fuel ratio of the mixture supplied to the internal-combustion engine is maintained at the first value when the air-fuel ratio decreases below the first value while the internal-combustion engine is operating in the first operating mode.
Claim 5
Dependent Claim
107 words
The hybrid vehicle driving method according to claim 2 , further comprising: estimating a second air-fuel ratio engine torque that would be produced by the internal-combustion engine when a fuel mixture having the second air-fuel ratio is supplied thereto; calculating a torque difference between an engine torque produced by the internal-combustion engine when a fuel mixture having the first air-fuel ratio is supplied thereto and the estimated second air-fuel ratio engine torque; and changing the operating mode of the internal-combustion engine from the first operating mode to the second operating mode when an output torque of the electric motor becomes approximately equal to the calculated torque difference.
Claim 6
Dependent Claim
94 words
The hybrid vehicle driving method according to claim 2 , further comprising: estimating a second air-fuel ratio engine torque produced by the internal-combustion engine when it is supplied with a mixture having the second air-fuel ratio; and changing the operating mode of the internal-combustion engine from the first operating mode to the second operating mode when the sum of an engine torque produced by the internal-combustion engine when a mixture of the first air-fuel ratio is supplied thereto and an output torque of the electric motor exceeds the estimated second air-fuel ratio engine torque.
Claim 7
Dependent Claim
46 words
The hybrid vehicle driving method according to claim 4 , further comprising: estimating the second air-fuel ratio engine torque, based on a driving torque variation that occurs when the operating mode of the internal-combustion engine changes from the first operating mode to the second operating mode.