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US 8,805,607 B2Granted
Vapour measurement
AssigneeRobert Bosch GmbH
InventorBenjamin David Smither
Life of this patent
Estimating the term…
Abstract
The present invention provides, with reference to FIG. 1, an internal combustion engine (10) having a fuel injector which comprises a sprung piston (55) or a resilient diaphragm piston (8155) and an electrical coil (57, 8158) for displacing the piston (55, 8155). The piston draws fuel into and expels fuel from a pumping chamber (52, 8152). The number of operations of the injector per engine cycle is controlled by an electronic controller (23, 8159) to control the quality of fuel delivered per cycle to a combustion chamber. A voltage measured in the coil (52, 8158) by movement of the piston under action of the spring or due to its own resilience is used to give an indication of vapour pressure of the fuel. A device akin to the injector can be used to draw fuel from a pipeline to measure the vapour pressure of the fluid.
Claims31
An internal combustion engine comprising:
- a variable volume combustion chamber;
- an air intake system for delivering charge air to the combustion chamber;
- an exhaust system for relaying combusted gas from the combustion chamber to atmosphere;
- and
- a fuel injection system for delivering fuel into the charge air for combustion therewith in the combustion chamber;
- wherein the fuel injection system comprises:
- a fuel injector which functions as a positive displacement pump and which comprises:
- a housing in which a pumping chamber is formed;
- an electrical coil;
- a piston which slides axially in a bore in the housing under action of the electrical coil;
- and a biasing spring which acts on the piston;
- and
- a controller which controls the operation of the fuel injector;
- wherein:
- in each of at least a majority of engine cycles the fuel injector is operated on a plurality of occasions by the controller;
- in response to an increasing engine speed and/or load the controller increases in amount the fuel delivered per engine cycle by increasing in number the occasions the fuel injector is operated per engine cycle;
- in response to a decreasing engine speed and/or load the controller reduces in amount the fuel delivered per engine cycle by reducing in number the occasions the fuel injector is operated per engine cycle;
- motion of the piston in a first direction draws fuel into the pumping chamber and motion of the piston in the opposite direction expels fluid from the pumping chamber;
- motion of the piston under action of the spring occasions a voltage in the coil;
- the controller uses the voltage occasioned by the piston motion under action of the spring to determine an indication of an amount of fuel vapour present in the pumping chamber;
- and
- the controller adjusts operation of the injector in dependence on the indicated amount of fuel vapour, the controller increasing in number the occasions the fuel injector is operated per engine cycle in response to an indication of an increased fuel vapour amount.
19 more elements
An internal combustion engine comprising:
- a variable volume combustion chamber;
- an air intake system for delivering charge air to the combustion chamber;
- an exhaust system for relaying combusted gas from the combustion chamber to atmosphere;
- and
- a fuel injection system for delivering fuel into the charge air for combustion therewith in the combustion chamber;
- wherein the fuel injection system comprises:
- a fuel injector which functions as a positive displacement pump and which comprises:
- a housing in which a pumping chamber is formed;
- an electrical coil;
- a piston in the form of a diaphragm which is displaceable under the action of the electrical coil against resilience of the diaphragm, which resilience then returns the diaphragm to an undisplaced condition;
- and
- a controller which controls the operation of the fuel injector;
- wherein:
- in each of at least a majority of engine cycles the fuel injector is operated on a plurality of occasions by the controller;
- in response to an increasing engine speed and/or load the controller increases in amount the fuel delivered per engine cycle by increasing in number the occasions the fuel injector is operated per engine cycle;
- in response to a decreasing engine speed and/or load the controller reduces in amount the fuel delivered per engine cycle by reducing in number the occasions the fuel injector is operated per engine cycle;
- displacement of the piston in a first direction draws fuel into the pumping chamber and displacement of the piston in the opposite direction expels fluid from the pumping chamber;
- return of the piston under action of the resilience thereof occasions a voltage in the coil;
- the controller uses the voltage occasioned by the piston motion under action of the resilience thereof to determine an indication of an amount of fuel vapour present in the pumping chamber;
- and
- the controller adjusts operation of the injector in dependence on the indicated amount of filet vapour, the controller increasing in number the occasions the fuel injector is operated per engine cycle in response to an indication of an increased fuel vapour amount.
18 more elements
A fuel injection method for delivery of fuel for combustion in a combustion chamber of an internal combustion engine, the method comprising:
- for a selected number of fuel delivery cycles in each engine operating cycle sequentially drawing into and then dispensing from a pumping chamber fuel for delivery to the combustion chamber;
- drawing fuel into and dispensing fuel from the pumping chamber by displacement of a sprung piston;
- displacing the sprung piston by applying an electromagnetic force to displace the piston against a spring then returning the piston by using the spring force;
- using the return of the piston under the spring force to generate an electrical signal;
- using the generated electrical signal to determine an amount of fuel vapour in the pumping chamber;
- and
- adjusting the selected number of fuel delivery cycles per engine operating cycle having regard to the determined amount of fuel vapour.
4 more elements
Dependencies are inferred from the claim text.