| 摘要 |
The control unit (2) receives input signals from (Q) a flowmeter or pressure sensor (3) in the intake manifold, (N) a engine speed sensor (4) and (Vs) a mixture richness sensor (5) in the exhaust, upstream of the catalyser (6). The basic fuel requirement (Tib) is calculated (21) by comparing measured air-flow and speed with previously tabulated test-based values set against fuel quantities. The fuel is delivered at rates alternating rapidly between limits not exceeding +/- 3% of a base value, engine conditions (Q,N) also determining (24) the frequency (F) employed, while the mean value is varied by PWM techniques. After treatment (23), the richness sensor's signal (Vsfil) is compared (26) with a reference value (Vc) and a correction factor is applied (25) to the delivery control unit (22).
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