SYSTEM AND METHOD FOR CALIBRATING FUEL INJECTORS IN AN ENGINE CONTROL SYSTEM THAT CALCULATES INJECTION DURATION BY MATHEMATICAL FORMULA
First Claim
1. A method of calibrating an electric-actuated fuel injector for an engine that uses injector control pressure to inject the fuel from the injector into the engine, before the fuel injector is installed in the engine, the method comprising:
- electrically actuating the fuel injector with a predetermined electric actuation at a first predetermined injector control pressure and measuring the resulting quantity of fuel injected;
electrically actuating the fuel injector with the predetermined electric actuation at a second predetermined injector control pressure and measuring the resulting quantity of fuel injected; and
correlating the measured quantities, the predetermined injection control pressures, and the applied predetermined electric actuation with values of quantity of fuel injected, injector control pressure, and electric actuation that are related by a predetermined multiple term mathematical formula to ascertain, for the same quantities of injected fuel at each predetermined injector control pressure, difference between the applied predetermined electric actuation and that required by the formula.
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Accused Products
Abstract
A method of modifying a general formula that is used by an engine control system (10) to calculate duration of fuel injector actuation. Coefficients (P1 coeff., P2 coeff., ICP coeff.) of the formula are modified to calibrate individual fuel injectors (16) in an engine. The amount of calibration needed is determined by data that is marked on each fuel injector in electronically readable format after the fuel injector has been operated and its operating characteristic ascertained. The control system reads the marked data and then makes the proper coefficient adjustment.
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Citations
8 Claims
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1. A method of calibrating an electric-actuated fuel injector for an engine that uses injector control pressure to inject the fuel from the injector into the engine, before the fuel injector is installed in the engine, the method comprising:
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electrically actuating the fuel injector with a predetermined electric actuation at a first predetermined injector control pressure and measuring the resulting quantity of fuel injected;
electrically actuating the fuel injector with the predetermined electric actuation at a second predetermined injector control pressure and measuring the resulting quantity of fuel injected; and
correlating the measured quantities, the predetermined injection control pressures, and the applied predetermined electric actuation with values of quantity of fuel injected, injector control pressure, and electric actuation that are related by a predetermined multiple term mathematical formula to ascertain, for the same quantities of injected fuel at each predetermined injector control pressure, difference between the applied predetermined electric actuation and that required by the formula. - View Dependent Claims (2, 3, 4)
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5. A system for calibrating an electric-actuated fuel injector for an engine that uses injector control pressure to inject the fuel from the injector into the engine, before the fuel injector is installed in the engine, the system comprising:
apparatus for
1) electrically actuating the fuel injector with a predetermined electric actuation at a first predetermined injector control pressure and measuring the resulting quantity of fuel injected;
2) electrically actuating the fuel injector with the predetermined electric actuation at a second predetermined injector control pressure and measuring the resulting quantity of fuel injected; and
3) correlating the measured quantities, the predetermined injection control pressures, and the applied predetermined electric actuation with values of quantity of fuel injected, injector control pressure, and electric actuation that are related by a predetermined multiple term mathematical formula to ascertain, for the same quantities of injected fuel at each predetermined injector control pressure, difference between the applied predetermined electric actuation and that required by the formula.- View Dependent Claims (6)
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7. An internal combustion engine comprising:
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one or more electric-actuated fuel injectors each of which injects fuel into a respective combustion chamber of the engine as a function of injector control pressure and the duration of an electric actuating signal that sets the duration of a fuel injection to achieve an injection quantity determined at least in part by a desired fueling data representing desired fueling of the engine;
and an engine control system comprising one or more processors that calculate the desired fueling data, and from the desired fueling data, the duration of the electric actuating signal for each fuel injector by processing the desired fueling data and data representing injector control pressure, including processing, according to a mathematical formula, data correlated with the desired fueling data and data representing injector control pressure, to develop data that the control system further processes to calculate the duration of the electric actuating signal;
wherein each fuel injector is marked with data that is entered into the engine control system incidental to installation of the fuel injector in the engine and that defines difference between the operating characteristic of the fuel injector and that of a general fuel injector on which the multiple term mathematical formula is based, and the control system modifies the formula for each fuel injector according to the marked data on each fuel injector to thereby calibrate each fuel injector in the engine so that each fuel injector injects fuel substantially in accordance with desired fueling data that is calculated by the control system and then is used in the formula as the quantity of injected fuel. - View Dependent Claims (8)
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Specification