| 摘要 |
Adequate controllability is ensured when feedback control is provided to both the EGR valve (21) and the intake throttle valve (23), and switching shock is prevented when control is switched from one to the other. The present apparatus comprises an EGR valve (21), an intake throttle valve (23), feedback control means (26) for providing feedback control to the EGR valve (21) and intake throttle valve such that the actual EGR volume approximates the target EGR volume corresponding to the running condition of the engine, and limiting means for limiting the operable opening ranges of the EGR valve (21) and intake throttle valve (23) in accordance with the target EGR volume. During EGR control of one valve, feedback control is provided to the other valve and the target opening is constantly calculated. The actual operations are merely limited, so these operations can start from the optimal opening and the switching shock can be prevented when a switch is made to the control of the other valve. <IMAGE> |
