Fuel injection apparatus for internal combustion engines
AssigneeRobert Bosch GmbH
InventorMax Straubel
Life of this patent
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Abstract
A fuel injection apparatus for internal combustion engines, which includes a pump piston guided in a cylinder bore driven to reciprocate axially by a cam drive. With a face end, the pump piston defines a pump work chamber, which communicates with an injection valve via a pressure conduit and which is supplied with fuel and relieved via a fuel line. Supply onset and supply end are controllable via a feed pump and a magnet valve are disposed in the fuel line, which communicates with a fuel supply vessel (33) to control supply onset and end of supply. In order to relieve a pressure of the high-pressure chambers, especially at high engine speeds, a fuel tapping device, which is controllable as a function of pressure is connected to a relief line that branches off from the fuel line.
Claims19
A fuel injection apparatus for internal combustion engines having a pump piston (1) guided in a cylinder bore (3) disposed in a pump housing (5) which is driven to axially reciprocate by a cam drive (7) and which with a face end (11) remote from the cam drive (7) defines a pump work chamber (13) which communicates via a pressure conduit (15) with an injection valve (17) which is supplied with fuel during an intake stroke of the pump piston (1) via a fuel line (31), a feed pump (35) which communicates with a fuel supply vessel (33) and said fuel line (31), a bypass line (39) which bypasses said feed pump, a control valve (37) in said fuel line (31) pump work chamber (13) for controlling a high-pressure fuel feed phase of the pump piston (1), a branch line (43) that branches off from said fuel line (31) on the pump work chamber side of the control valve (37), a fuel tapping device (45) disposed in said branch line (43) which opens at a fixed pressure corresponding to an upper engine speed range.
Dependencies are inferred from the claim text.