Diesel engine control
AssigneeNissan Motor Co., Ltd.
InventorHiroyuki Itoyama
Life of this patent
Estimating the term…
Abstract
In a diesel engine provided with an exhaust gas recirculation valve (6), a target exhaust gas recirculation amount determined based on the engine running condition is compared with a maximum recirculation amount of the valve (6) (S28). When the target exhaust gas recirculation amount exceeds the maximum recirculation amount, the target exhaust gas recirculation amount is limited to the maximum flowrate (S28). By maintaining the opening of the exhaust gas recirculation valve (6) at an opening corresponding to the maximum recirculation amount for a predetermined time even after the target exhaust recirculation amount has fallen below the maximum flowrate (S26), the exhaust gas recirculation amount is made to promptly follow the target amount.
Claims13
A control device for an engine (1), the engine comprising a combustion chamber (1A), an intake passage (3) which aspirates air into the combustion chamber (3A), an exhaust passage (2) which discharges exhaust gas from the combustion chamber (3A), and an exhaust gas recirculation valve (6) which recirculates part of the exhaust gas of the exhaust passage (2) into the combustion chamber (1A), the device comprising:
- a sensor (34, 39) which detects a running condition of the engine (1);
- and
- a microprocessor (41) programmed to:
- set a target exhaust gas recirculation amount based on the running condition (S25, S26);
- determine a maximum recirculation amount of the exhaust gas recirculation valve (6) (S27);
- compare the target exhaust gas recirculation amount with the maximum recirculation amount (S28);
- limit the target exhaust gas recirculation amount to be equal to the maximum recirculation amount when the target exhaust gas recirculation amount exceeds tile maximum recirculation amount (S28);
- control the opening of the exhaust gas recirculation valve (6) based on the target exhaust gas recirculation amount (S29);
- and
- maintain the opening of the exhaust gas recirculation valve (6) at an opening corresponding to the maximum recirculation amount for a predetermined time after the target exhaust gas recirculation amount has fallen below the maximum recirculation amount (S26).
A control device for an engine (1), the engine comprising a combustion chamber (1A), an intake passage (3) which aspirates air into the combustion chamber (3A), an exhaust passage (2) which discharges exhaust gas from the combustion chamber (3A), and an exhaust gas recirculation valve (6) which recirculates part of the exhaust gas of the exhaust passage (2) into the combustion chamber (1A), the device comprising:
- means (34, 39) for detecting which a running condition of the engine (1);
- means (41, S25, S26) for setting a target exhaust gas recirculation amount based on the running condition;
- means (41, S27) for determining a maximum recirculation amount of the exhaust gas recirculation valve (6);
- means for (41, S28) for comparing the target exhaust gas recirculation amount with the maximum recirculation amount;
- means (41, S28) for limiting the target exhaust gas recirculation amount to be equal to the maximum recirculation amount when the target exhaust gas recirculation amount exceeds the maximum recirculation amount;
- means (41, S29) for controlling the opening of the exhaust gas recirculation valve (6) based on the target exhaust gas recirculation amount;
- and
- means (41, S26) for maintaining the opening of the exhaust gas recirculation valve (6) at an opening corresponding to the maximum recirculation amount for a predetermined time after the target exhaust gas recirculation amount has fallen below the maximum recirculation amount.
A control method for an engine (1), the engine comprising a combustion chamber (1A), an intake passage (3) which aspirates air into the combustion chamber (3A), an exhaust passage (2) which discharges exhaust gas from the combustion chamber (3A), and an exhaust gas recirculation valve (6) which recirculates part of the exhaust gas of the exhaust passage (2) into the combustion chamber (1A), the method comprising:
- detecting which a running condition of the engine (1);
- setting a target exhaust gas recirculation amount based on the running condition,
- determining a maximum recirculation amount of the exhaust gas recirculation valve (6);
- comparing the target exhaust gas recirculation amount with the maximum recirculation amount;
- limiting the target exhaust gas recirculation amount to be equal to the maximum recirculation amount when the target exhaust gas recirculation amount exceeds the maximum recirculation amount;
- controlling the opening of the exhaust gas recirculation valve (6) based on the target exhaust gas recirculation amount;
- and
- maintaining the opening of the exhaust gas recirculation valve (6) at an opening corresponding to the maximum recirculation amount for a predetermined time after the target exhaust gas recirculation amount has fallen below the maximum recirculation amount.
Dependencies are inferred from the claim text.