Fuel injector with spill chamber
AssigneeRobert Bosch GmbH
InventorMark Bos
Life of this patent
Estimating the term…
Abstract
A fuel injection system has a spill chamber fluidly connected between a high pressure side and low pressure side with a spill valve that is synchronized with the control valve. The spill chamber has a movable piston that is pressure balanced at a first position during fuel injection and fuel filling, but moves to a second position increasing volume in the high pressure side during a spill event at the termination of injection.
Claims26
In a fuel injection system comprising a pump fluidly connected to an injector nozzle by way of a high pressure conduit in a high pressure side for pressurizing fuel in the high pressure side prior to an injection event, and a control valve fluidly connected between the high pressure side and a low pressure side wherein the injection event occurs by opening the injector nozzle when the control valve is activated and the injection event is terminated by a spill event when the control valve is deactivated, the improvement comprising:
- a spill chamber with a movable piston, fluidly connected between the high pressure side and the low pressure side, wherein the piston is movable between a first position that provides no change in the volume of the high pressure side and a second position that increases the volume of the high pressure side, and
- means to hold the piston in the first position until the termination of an injection event, whereby to absorb stored energy in the pressurized fuel during a spill event.
In a fuel injection system comprising a pump fluidly connected to an injector nozzle by way of a high pressure conduit in a high pressure side for pressurizing fuel in the high pressure side prior to an injection event, and a control valve fluidly connected between the high pressure side and a low pressure side wherein the injection event occurs by opening the injector nozzle when the control valve is activated and the injection event is terminated by a spill event when the control valve is deactivated, the improvement comprising:
- a spill chamber fluidly connected to the high pressure side, with a movable piston dividing the spill chamber into a first side and a second side, the spill chamber being configured to bias the piston toward the second side only until termination of an injection event, whereby to accelerate pressure drop in the high pressure side and overcome the effects of inertia in the control valve during a spill event.
Dependencies are inferred from the claim text.