| 摘要 |
1332524 Fuel injection systems ROBERT BOSCH GmbH 19 Jan 1971 [22 Jan 1970] 2668/71 Heading G1N In an I.C. engine fuel injection control system, basic injection valve opening pulses I n produced by a monostable multi-vibrator 25 are prolonged by a pulse I v provided by a device 27, the total pulse length I g being prolonged at starting and initial running during an interval of between 5 and 30 seconds by the effect of a timing device 30 which is actuated by the starting switch 96, this interval being independent of changes in the operating temperature of the engine. During normal running, during the pulse I n , a capacitor 60 of the device 27 is charged through a transistor 61, and at the end of the pulse I n is discharged, the discharge time being the duration of the prolongation pulse I v . When the starter switch is closed, transistors 85, 86 became conductive and the approximately negative lead voltage on the collector of transistor 86 causes the charging current through transistor 61 to be increased and thus the prolongation pulse I v to be increased. For the approximately 20 second period after switch 96 is released, the transistors 85, 86 attempt to return to their non-conductive condition, which they reach when capacitor 89 is fully charged. As 89 charges, an increasing voltage appears on the collector of transistor 86 which gradually decreases the charging current through transistor 61 and hence the length of the pulse I v , as shown in Fig.2. In a simplified embodiment of the timing device 30, Fig.3 (not shown), a single transistor is used, and in a modification of the timing device 30 shown in Fig.1, Fig.4 (not shown), the resistor 90 is omitted, which has the effect of enabling the value of capacitor 89 to be reduced and to make its duration dependent upon the speed and length of the basic pulses I n . |
