摘要:
An air-fuel ratio control system maintaining constant an oxygen storage amount or oxygen release amount per unit time with respect to an exhaust purification catalyst having an oxygen storage capacity even if the intake air amount changes is provided.An air-fuel ratio control system of an internal combustion engine having an intake air amount detecting means, a linear air-fuel ratio sensor arranged at an upstream side of an exhaust purification catalyst, an O2 sensor arranged at a downstream side of said exhaust purification catalyst, a target air-fuel ratio controlling means for performing feedback control of a target air-fuel ratio of exhaust flowing into the exhaust purification catalyst based on output information from the intake air amount detecting means and the O2 sensor, and a fuel injection amount controlling means for performing feedback control of the fuel injection amount based on output information of the linear air-fuel ratio sensor so as to achieve the target air-fuel ratio, characterized in that the target air-fuel ratio controlling means performs feedback control of the target air-fuel ratio so that even when the intake air amount changes, a correction amount per unit time of an oxygen storage amount of the exhaust purification catalyst is made constant.
摘要:
An air-fuel ratio control device includes an air-fuel ratio sensor provided upstream from a three-way catalyst, and an oxygen sensor provided downstream from the three-way catalyst. The air-fuel ratio control device controls the fuel supply amount based on the output from the air-fuel ratio sensor, and compensates for errors in the air-fuel ratio sensor by correcting the fuel supply amount based on the output from the oxygen sensor. The fuel supply correction amount is calculated based on an integral term that integrates the deviation between the output from the downstream air-fuel ratio sensor and the target air-fuel ratio. When a fuel supply adjustment control is executed, the value of the integral term in the sub-feedback control is not updated for a predetermined period after the fuel supply adjustment control ends. The actual air-fuel ratio is thus brought to the target air-fuel ratio in an appropriate manner.
摘要:
An air-fuel ratio control device includes an air-fuel ratio sensor provided upstream from a three-way catalyst, and an oxygen sensor provided downstream from the three-way catalyst. The air-fuel ratio control device controls the fuel supply amount based on the output from the air-fuel ratio sensor, and compensates for errors in the air-fuel ratio sensor by correcting the fuel supply amount based on the output from the oxygen sensor. The fuel supply correction amount is calculated based on an integral term that integrates the deviation between the output from the downstream air-fuel ratio sensor and the target air-fuel ratio. When a fuel supply adjustment control is executed, the value of the integral term in the sub-feedback control is not updated for a predetermined period after the fuel supply adjustment control ends. The actual air-fuel ratio is thus brought to the target air-fuel ratio in an appropriate manner.
摘要:
An air-fuel ratio control system of a multi-cylinder internal combustion engine provided with a throttle valve and opening characteristic control means, which system performs feedback control of an air-fuel ratio based on an output of a sensor detecting an air-fuel ratio of exhaust gas and is capable of performing more accurate air-fuel ratio control, is provided. In the feedback control, the relationship of the output of the sensor and a feedback value is corrected based on a feedback learning correction value learned and determined based on the output of the sensor during the feedback control, and, when newly learning the feedback learning correction value, the intake air amount is controlled by only the throttle valve.
摘要:
An air-fuel ratio control system of a multi-cylinder internal combustion engine provided with a throttle valve and opening characteristic control means, which system performs feedback control of an air-fuel ratio based on an output of a sensor detecting an air-fuel ratio of exhaust gas and is capable of performing more accurate air-fuel ratio control, is provided. In the feedback control, the relationship of the output of the sensor and a feedback value is corrected based on a feedback learning correction value learned and determined based on the output of the sensor during the feedback control, and, when newly learning the feedback learning correction value, the intake air amount is controlled by only the throttle valve.
摘要:
The output from an air-fuel ratio sensor is corrected using an integral term that is calculated by integrating values of deviation of the output from an oxygen sensor with respect to a reference output that would be obtained when the combustion air-fuel ratio is stoichiometric, when an engine operates with a target combustion air-fuel ratio set to the stoichiometric air-fuel ratio. A fuel-cutoff prohibition period in which fuel supply cutoff is prohibited is set so that the engine continues to operate with the target combustion air-fuel ratio set to the stoichiometric air-fuel ratio, until the integral term is updated at least once. The integral term may be updated when a predetermined updating condition is satisfied.
摘要:
An air-fuel ratio control system maintaining constant an oxygen storage amount or oxygen release amount per unit time with respect to an exhaust purification catalyst having an oxygen storage capacity even if the intake air amount changes is provided.An air-fuel ratio control system of an internal combustion engine having an intake air amount detecting means, a linear air-fuel ratio sensor arranged at an upstream side of an exhaust purification catalyst, an O2 sensor arranged at a downstream side of said exhaust purification catalyst, a target air-fuel ratio controlling means for performing feedback control of a target air-fuel ratio of exhaust flowing into the exhaust purification catalyst based on output information from the intake air amount detecting means and the O2 sensor, and a fuel injection amount controlling means for performing feedback control of the fuel injection amount based on output information of the linear air-fuel ratio sensor so as to achieve the target air-fuel ratio, characterized in that the target air-fuel ratio controlling means performs feedback control of the target air-fuel ratio so that even when the intake air amount changes, a correction amount per unit time of an oxygen storage amount of the exhaust purification catalyst is made constant.
摘要翻译:即使提供进气量变化,也能够提供相对于具有储氧能力的排气净化催化剂,每单位时间保持恒定氧气储存量或氧释放量的空燃比控制系统。 一种内燃机的空燃比控制系统,具有进气量检测装置,布置在排气净化催化剂的上游侧的线性空燃比传感器,配置有O 2传感器 在所述排气净化催化剂的下游侧,基于来自所述进气量检测单元的输出信息,对所述排气净化催化剂的排气进行目标空燃比的反馈控制的目标空燃比控制单元, O 2传感器,以及燃料喷射量控制装置,用于基于线性空燃比传感器的输出信息执行燃料喷射量的反馈控制,以实现目标空燃比, 其特征在于,所述目标空燃比控制单元对所述目标空燃比进行反馈控制,使得即使在所述进气量变化时,每单位时间的氧气存储量的修正量 使排气净化催化剂的量保持恒定。
摘要:
The present invention relates to an air-fuel ratio control device for an internal combustion engine, and makes it possible to maintain high purification performance by suppressing a decrease in the oxygen occlusion capability of a catalyst. When an O2 sensor output oxs is greater than a reference value oxsref, which corresponds to a stoichiometric air-fuel ratio, and smaller than an upper threshold value oxsrefR, a sub-FB reflection coefficient is fixed at a predetermined value vdox2 for providing a lean air-fuel ratio. When, on the other hand, the O2 sensor output oxs is smaller than the reference value oxsref and greater than a lower threshold value oxsrefL, the sub-FB reflection coefficient is fixed at a predetermined value vdox2 for providing a rich air-fuel ratio. The sub-FB reflection coefficient reflects the O2 sensor output oxs in the calculation of a fuel injection amount and increases or decreases to have a consequence on the air-fuel ratio of an exhaust gas.
摘要:
The present invention relates to an air-fuel ratio control device for an internal combustion engine, and makes it possible to maintain high purification performance by suppressing a decrease in the oxygen occlusion capability of a catalyst. When an O2 sensor output oxs is greater than a reference value oxsref, which corresponds to a stoichiometric air-fuel ratio, and smaller than an upper threshold value oxsrefR, a sub-FB reflection coefficient is fixed at a predetermined value vdox2 for providing a lean air-fuel ratio. When, on the other hand, the O2 sensor output oxs is smaller than the reference value oxsref and greater than a lower threshold value oxsrefL, the sub-FB reflection coefficient is fixed at a predetermined value vdox2 for providing a rich air-fuel ratio. The sub-FB reflection coefficient reflects the O2 sensor output oxs in the calculation of a fuel injection amount and increases or decreases to have a consequence on the air-fuel ratio of an exhaust gas.
摘要:
A fuel injection amount is controlled so that the air-fuel ratio of exhaust gas flowing into a catalyst (6) oscillates around a stoichiometric air-fuel ratio. When it is estimated that the level of oxygen storage capacity of the catalyst (6) is lower than a predetermined reference capacity, the amplitude of the air-fuel ratio of the exhaust gas which oscillates around the stoichiometric air-fuel ratio is reduced by controlling the fuel injection amount. The level of the oxygen storage capacity of the catalyst (6) is estimated based on the amplitude of the output signal from an oxygen sensor (14) disposed downstream of the catalyst (6).