| 摘要 |
1308810 Fuel injection pumps ROBERT BOSCH GmbH 18 Sept 1970 [19 Sept 1969(2)] 44609/70 Heading F1A In a fuel injection pump in which the delivery is controlled by a spill valve 14 actuated by liquid delivered by an auxiliary piston 18 movable with the injection piston 2, the valve 14 controls connection between a spill passage 16a and two low-pressure passages 16b, 33. The passage 33 is connected to the spill passage 16a before the passage 16b, but the passage 33 is only open during part of the stroke of the pistons 2, 18. The closing of the passage 33 occurs when a groove 34 in the piston 2 no longer connects the two parts of the passage 33. In operation at full load, opening of the passage 33 only occurs after it has been previously closed by the piston 2, so that no spillage occurs through the passage 33. When "hydraulic stop" of the valve 14 occurs, as determined by the adjusted size of a variable orifice 31, the passage 33 is connected to the spill passage 16a and some fuel spills before the passage 33 is closed by the piston 2. Delivery then re-commences until the passage 16b is opened. Fuel spilling through the passage 33 may be controlled by a fixed throttle formed in the valve 14, Figs.4 and 5 (not shown) or by a needle valve in the passage 33, Fig.3 (not shown). |
