| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fuel injection control device of an engine with a selective reduction catalyst device which can improve fuel consumption while preventing the deterioration of purifying capability. <P>SOLUTION: The fuel injection control device includes an SCR device 4 disposed on an exhaust pipe 3 of the engine 2, an upstream-side NOx sensor 5 which detects an NOx concentration on the upstream side to the SCR device 4, a downstream-side NOx sensor 6 which detects an NOx concentration on the downstream side to the SCR device 4, a purification rate calculating unit 7 which calculates a purification rate E at the SCR device 4 based on an NOx concentration detected by the upstream-side NOx sensor 5 and an NOx concentration detected by the downstream-side NOx sensor 6, and a fuel injection time control unit 8 which controls fuel injection time of the engine 2 to a standard fuel injection time when the purification rate E at the SCR device 4 is fine while controlling the fuel injection time of the engine 2 to a fuel injection time at which exhaust gas is more clear than exhaust gas at the standard fuel injection time when the purification rate E at the SCR device 4 is deteriorated. <P>COPYRIGHT: (C)2012,JPO&INPIT |
