发明授权
- 专利标题: Method and apparatus using a gas concentration sensor for accurately controlling an air fuel ratio in an internal combustion engine
- 专利标题(中): 使用气体浓度传感器来精确地控制内燃机的空燃比的方法和装置
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申请号: US09480661申请日: 2000-01-11
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公开(公告)号: US06568240B1公开(公告)日: 2003-05-27
- 发明人: Yoshikuni Sato , Noboru Ishida , Hideki Ishikawa , Takafumi Oshima , Yasushi Sato
- 申请人: Yoshikuni Sato , Noboru Ishida , Hideki Ishikawa , Takafumi Oshima , Yasushi Sato
- 优先权: JP11-004285 19990111
- 主分类号: G01N2726
- IPC分类号: G01N2726
摘要:
The present invention provides a method and apparatus using a gas concentration sensor for accurately controlling an air fuel ratio in an internal combustion engine, featuring in that before the fuel-vaporized gas purged from the canister enters into the intake manifold whereat the sensor detects the gas concentration of the purged gas, the sensor is adjusted so as to adjust a zero point (or zero output level) of the sensor output. In step 100 of FIG. 7, a judgment is made as to whether the flow rate of air reaches a predetermined level. In step 110, processing for zero-point correction of the gas concentration sensor is performed. Specifically, in a state in which the purge valve 17 is closed, concentration of purge gas is measured by use of the gas concentration sensor 4, and a sensor output S1 at that time is obtained. Subsequently, the sensor output S1 is compared with a correct sensor output S0 in order to obtain a difference &Dgr;S therebetween. Accordingly, during subsequent gas concentration measurement, a value S3 obtained through subtraction of the difference &Dgr;S from an obtained sensor output S2 is used as a correct sensor output. In step 120, a supply amount of purge gas, i.e., a concentration of the purge gas to be supplied is obtained. In subsequent step 130, the purge valve 17 is driven in order to supply purge gas to the intake pipe 2 in a required amount (A%).