Injection pump having cold start acceleration for direct injection internal combustion engines
AssigneeRobert Bosch GmbH
InventorsHelmut Simon, Helmut Haberer
Life of this patent
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Abstract
A fuel delivery unit for an internal combustion engine including a housing, which includes a timing unit for shifting the point of injection of fuel into the combustion chambers of the internal combustion engine. An injection timing piston is accommodated in the timing unit, which is displaceably mounted in the timing unit and which encloses a trailing piston displaceably relative thereto. The timing unit contains a pressure chamber which may be pressurized/depressurized via an actuator, a cold start accelerator piston being movable via the pressure chamber, acting upon both the trailing piston via a spring element and, together with a spring-sleeve combination, influencing the injection timing piston.
Claims11
A fuel delivery unit, comprising:
- a housing;
- a timing unit disposed in the housing configured to shift a point of injection of fuel into a combustion chamber of an internal combustion engine, the timing unit including a pressure chamber which is configured to be at least one of pressurized and depressurized by an actuator;
- an injection timing piston movably disposed in the timing unit;
- a trailing piston/regulating slide disposed within the injection timing piston configured to be displaceable relative to the injection timing piston;
- and
- a cold start accelerator piston configured to be displaced by the pressure chamber and to act on the trailing piston/regulating slide via a spring element;
- wherein the cold start accelerator piston is further configured to act on the injection timing piston via a spring-sleeve combination.
Dependencies are inferred from the claim text.