Electronically controlled fuel injection method and apparatus
First Claim
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1. A method of electronically controlling the rate of fuel being injected at low engine temperatures into an engine having a combustion chamber and a crank-shaft comprising the steps of:
- (a) monitoring a pressure P in said combustion chamber;
(b) determining said P at a plurality of predetermined intervals during compression and explosion strokes from 180°
before top dead center to 180°
after top dead center;
(c) generating, in response to said determining step, an integrated pressure value Pi related to the integral of the product of P and the incremental change in combustion chamber volume per incremental change in crank-shaft angle over the range of crank-shaft angles from 180°
before top dead center to 180°
after top dead center during the compression and explosion strokes;
(d) generating a pumping means effective pressure value Pp related to the difference between combustion chamber pressures during an intake stroke and an exhaust stroke of said engine;
(e) generating a torque value T related to said Pi less Pf and said Pp where Pf is related to a frictional average effective pressure; and
(f) adjusting said fuel injection rate so that T approaches a predetermined optimum torque,said steps (d), (e) and (f) occurring during one of an exhaust stroke and an intake stroke of said engine,said steps (c), (d) and (e) being performed by a microcomputer.
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Abstract
An electronically controlled, fuel injection method and apparatus, wherein fuel is supplied by an electromagnetic fuel injection valve into an intake system. The rate of fuel injection when the engine is cold is increased or decreased in relation to a difference between a detected engine torque and a predetermined optimum torque. Consequently, good operational performance of the engine at low engine temperature is ensured, irrespective of variations in ambient factors such as atmospheric pressure, etc. and variations in engine characteristics.
20 Citations
10 Claims
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1. A method of electronically controlling the rate of fuel being injected at low engine temperatures into an engine having a combustion chamber and a crank-shaft comprising the steps of:
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(a) monitoring a pressure P in said combustion chamber; (b) determining said P at a plurality of predetermined intervals during compression and explosion strokes from 180°
before top dead center to 180°
after top dead center;(c) generating, in response to said determining step, an integrated pressure value Pi related to the integral of the product of P and the incremental change in combustion chamber volume per incremental change in crank-shaft angle over the range of crank-shaft angles from 180°
before top dead center to 180°
after top dead center during the compression and explosion strokes;(d) generating a pumping means effective pressure value Pp related to the difference between combustion chamber pressures during an intake stroke and an exhaust stroke of said engine; (e) generating a torque value T related to said Pi less Pf and said Pp where Pf is related to a frictional average effective pressure; and (f) adjusting said fuel injection rate so that T approaches a predetermined optimum torque, said steps (d), (e) and (f) occurring during one of an exhaust stroke and an intake stroke of said engine, said steps (c), (d) and (e) being performed by a microcomputer. - View Dependent Claims (3, 4, 5, 6)
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2. Apparatus for electronically controlling the rate of fuel being injected at low engine temperatures into an engine having a combustion chamber and a crank-shaft comprising:
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means for monitoring a pressure P in said combustion chamber; microcomputer processing means for (1) determining said P at a plurality of predetermined intervals during compression and explosion strokes from 180°
before top dead center to 180°
after top dead center and during each intake stroke and exhaust stroke, (2) generating, in response to said determining step, an integrated pressure value Pi related to the integral of the product of P and the incremental change in combustion chamber volume per incremental change in crank-shaft angle over the range of crank-shaft angles from 180°
before top dead center to 180°
after top dead center during the compression and explosion strokes, (3) generating a pumping means effective pressure value Pp related to the difference between combustion chamber pressures during an intake stroke and an exhaust stroke of said engine, (4) generating a torque value T related to said Pi less Pf and said Pp where Pf is related to a frictional average effective pressure, and (5) determining the amount by which said fuel injection rate should be adjusted so that T approaches a predetermined optimum torque, said microcomputer processing means functions (3), (4) and (5) occurring during one of an exhaust stroke and an intake stroke of said engine; andmeans, responsive to said microcomputer processing means for adjusting said fuel injection rate. - View Dependent Claims (7, 8, 9, 10)
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Specification