| 摘要 |
1,270,274. Automatic control of speed. ROBERT BOSCH G.m.b.H. July 23, 1969 [July 24, 1968], No.36918/69. Heading G3R. The speed of an internal combustion engine, e.g. a diesel in a vehicle, is controlled by adjusting its fuel supply (by injector pump setting) in response to the voltage on a terminal 65, to which is connected a first voltage source of high impedance (U71 and divider 68, 69), a second voltage source (low impedance) dependent upon engine speed (tachogenerator 12), and a third voltage source (low impedance) dependent on a setting device (U53, divider 52 with pedal operated rheostat 51), the second and third voltages being in series opposition and in series with an element conductive in only one direction, which may be a diode 63 or a transistor. The first voltage is sufficient to provide maximum fuel short of that which would produce smoke, the element 63 being back biased by the reference voltage. When the desired speed is reached the tachogenerator voltage exceeds the reference, forward biasing 63 and opposing the voltage from the first source, hence reducing the potential on terminal 65 and so also the fuel supply. A drop in speed will again cause 63 to be back biased and the fuel increased. The maximum amount of fuel which can be admitted is increased for starting by means not shown. The amount of "droop" in the speed/load characteristic is controlled by a rheostat 64. The tachogenerator has a second winding which produces a fourth voltage opposing a fixed, fifth voltage from a divider 56, 57, connected to terminal 65 via a second element 66. This is adjusted by a rheostat 67 to modify the speed/fuel characteristic at higher speeds only to provide "full load adaptation" and an ultimate speed limit, Fig. 3 (not shown). The D.C. tachogenerator shown may be replaced by an A, C. one, with a rectifier and smoothing circuit connected to terminal 65. The voltage on 65 effects control by an amplifier and electro-hydraulic servosystem, with positional feedback of the pump regulating lever. The resistors 52 and 57 may be temperature and/or pressure sensitive to compensate for varying ambient and atmospheric conditions. |
