Fuel injection system with fuel pressure intensification
AssigneeDaimlerChrysler AG
InventorVolker Schwarz
Life of this patent
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Abstract
In an injection system with pressure intensification with a simple and space-saving design, control means are provided permitting a large range fuel injection pressure control, which also permits rapid adaptation of the fuel injection pressure to the various engine operating conditions.
Claims9
An injection system operating with pressure intensification, comprising:
- a fuel injector (3), a pressurized fuel source (2) for supplying fuel to said fuel injector (3), said fuel injector (3) including a nozzle needle (5) having a tip and an actuation space (7) disposed at the rear end of said nozzle needle (5) remote from the tip thereof and being connected to an inlet line (9, 14) extending from said pressurized fuel source (2) and also to a fuel return (11), said injection system having a fuel inlet line portion (14) with a non-return valve (15) preventing fuel return to the pressure source (2), a pressure intensifier (13) in communication with said inlet line (9) and comprising a fuel receiver (16) in communication with said fuel source (2) and a pressure transmitter (17), which has a working surface (19) smaller than the working surface (18) of said fuel receiver (16) and which is connected to the inlet line (9) to the actuating space (7) of the fuel injector (3), said pressure intensifier (13) including a spring (47) providing a force on the pressure receiver (16) which biases the pressure receiver (16) in the direction toward said pressure fuel source (2), a throttled connecting line (22) extending from said fuel source (2) to a control space (20) at the surface of the pressure receiver opposite the working surface (18) thereof, the control space (20) and the actuation space (7) being connected to the return line (11) by way of a common control valve (25).
An injection system operating with pressure intensification, including a fuel injector (3) supplied with an injection fuel from a pressure source (2), said fuel injector (30) comprising a nozzle needle (5) with a tip and an actuation space (7) disposed at the rear end of said nozzle-needle (5) opposite the tip thereof and connected to a fuel inlet line (9, 14) extending from said pressure source (2) and in a throttled manner to a fuel return line (11), said fuel inlet line (9, 14) including a portion (19) with a non-return valve (15) disposed in said portion, a pressure intensifier (13) comprising a pressure receiver (16) and a pressure transmitter (17) having a smaller working surface (19) than said pressure receiver (16) and being connected to said inlet line (9) extending to said actuation space (7), said fuel pressure intensifier (13) including a spring (47) biasing said pressure transmitter (17) against the pressure source (2), a connection with a throttle (21) extending from said pressure source (2) to a control space (20) provided at the opposite surface of the pressure receiver (16), the control space (20) and the actuation space (7) being both connected to a return line (11) individually by way of control valves (25, 29), one of said control valves (29) for the connection of the control space (20) to the return line (11) being a spool valve (29) disposed on the nozzle needle (5) and the other control valve (25) for controlling the fuel flow from the actuation space (7) of the fuel injector (3) being an electrically operated value (25).
An injection system operating with pressure intensification, including a fuel injector (3) receiving fuel from a pressure source (2), and including a nozzle needle (5) with a tip and an actuation space (7) disposed on the rear side of said nozzle needle (5) opposite said tip, said actuation space (7) being connected to an inlet line (9) extending from said pressure source (2) and also in a throttled manner to a return line (11), said injection system having disposed, in a section (14) of the inlet line (9) leading to sail fuel injector (3), a non-return protection valve (15), a pressure intensifier (13) comprising a pressure receiver (16) connected to said pressure source (2) and a pressure transmitter connected to said fuel inlet line (9) and having a working surface smaller than that of said pressure receiver (16) said pressure intensifier (13) including a spring (47) biasing said pressure receiver (16) with its working surface in a direction opposite to said pressure transmitter and toward the pressure source (2), a fuel connection line with a throttle (21) extending to a control space (20) at the side of the pressure receiver (16) opposite said working surface thereof, said control space (20) and said actuation space (7) being individually connected to said return (11) by separate control valves (25, 32), one (25) off said control valves (25, 32) being connected by a connecting line (10) to said actuation space (7)and the other control valve (32) disposed in the connection line (31) or the control space (20) and said return (11) and comprising a control spool (33) connected for pressure control to a connection line branched off from the inlet line (9) and, respectively, a connection line extending between the connection line (10) off the other control valve (25) and the actuation space (7) of the injector (3).
Dependencies are inferred from the claim text.