Exhaust purifying apparatus for internal combustion engine
AssigneesToyota Jidosha Kabushiki Kaisha, Kabushiki Kaisha Toyota Jidoshokki
InventorsHisanobu Suzuki, Yoshitaka Nakamura, Yoshiyuki Takahashi, Yuzuru Ikeda, Shinichi Kusakabe, Tadashi Toyota
Life of this patent
Estimating the term…
Abstract
An internal combustion engine has a separate exhaust passage for each one of banks. An exhaust purifying catalyst is provided in each exhaust passage. The mass flow rates G1, G2 of exhaust gas that flow through the exhaust passages are individually estimated. The flow rate of exhaust gas is individually adjusted per each bank by controlling the operation of each one of exhaust gas recirculation valves such that the difference between the estimated mass flow rates G1, G2 is decreased.
Claims8
An exhaust purifying apparatus applied to an internal combustion engine, which has a plurality of groups of cylinders, each group being connected to different one of exhaust purifying catalysts, the apparatus comprising:
- estimating means for individually estimating the flow rate of exhaust gas in each exhaust purifying catalyst;
- and
- setting means for individually setting the control manner of each group of cylinders connected to the corresponding exhaust purifying catalyst in accordance with the estimated flow rate of exhaust gas of the exhaust purifying catalyst,
- wherein the exhaust passages are merged together after exhaust gas of each group of cylinders pass through the corresponding exhaust purifying catalyst;
- and wherein the estimating means estimates the flow rate of exhaust gas by computing a mass flow rate G1 of exhaust gas that passes through the first exhaust purifying catalyst and a mass flow rate G2 of exhaust gas that passes through the second exhaust purifying catalyst based on a temperature T1 of exhaust gas that passes through the first exhaust purifying catalyst, a temperature T2 of exhaust gas that passes through the second exhaust purifying catalyst a temperature T of exhaust gas after merging together, and a mass flow rate G of exhaust gas after merging together using the following equations (1) and (2):
- G1=G(T−T2)/(T1−T2) (1) G2=G(T−T1)/(T2−T1) (2).
An exhaust purifying method applied to an internal combustion engine, which has a plurality of groups of cylinders, each group being connected to different one of exhaust purifying catalysts and also has exhaust passages each corresponding to one of the groups of the cylinders, wherein the exhaust passages are merged together after exhaust gas of each group of the cylinders passes through the corresponding exhaust purifying catalyst, the method comprising:
- individually estimating the flow rate of exhaust gas in each exhaust purifying catalyst;
- and
- individually setting the control manner of each group of cylinders connected to the corresponding exhaust purifying catalyst in accordance with the estimated flow rate of exhaust gas of the exhaust purifying catalyst,
- wherein the flow rate of exhaust gas is estimated by computing a mass flow rate G1 of exhaust gas that passes through the first exhaust purifying catalyst and a mass flow rate G2 of exhaust gas that passes through the second exhaust purifying catalyst based on a temperature T1 of exhaust gas that passes through the first exhaust purifying catalyst, a temperature T2 of exhaust gas that passes through the second exhaust purifying catalyst, a temperature T of exhaust gas after merging together, and a mass flow rate G of exhaust gas after merging together using the following equations (1) and (2):
- G1=G×(T−T2)/(T1−T2) (1)
- G2=G×(T−T1)/(T2−T1) (2).
Dependencies are inferred from the claim text.