Misfiring sensing apparatus
First Claim
1. A misfiring sensing apparatus for an engine equipped with a crankshaft and at least one cylinder having a piston connected to the crankshaft, comprising:
- period sensing means for sensing a length of a first period equal to a length of time for the crankshaft of the engine to rotate between first and second angular positions and for sensing a length of a different second period equal to a length of time for the crankshaft to rotate between third and fourth angular positions; and
misfiring sensing means for sensing misfiring of the engine based on a ratio of the lengths of the first and second periods.
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Accused Products
Abstract
A misfiring sensing apparatus for an internal combustion engine measures the length of time required for two periods during the operation of an engine, each of the periods corresponding to a predetermined number of degrees of rotation of the crankshaft of the engine and corresponding to prescribed positions of the pistons of the engine. The two periods are selected so that the ratio of the lengths of the two periods will change when one of the cylinders of the engine is misfiring. Misfiring is detected based on the value of the ratio. In one form of the invention, misfiring is sensed by comparing the ratio with a reference value. In another form of the invention, the ratio is used to calculate a value indicative of the current angular acceleration of the crankshaft of the engine, and the calculated value is compared with a reference value to determine whether knocking is taking place.
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Citations
23 Claims
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1. A misfiring sensing apparatus for an engine equipped with a crankshaft and at least one cylinder having a piston connected to the crankshaft, comprising:
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period sensing means for sensing a length of a first period equal to a length of time for the crankshaft of the engine to rotate between first and second angular positions and for sensing a length of a different second period equal to a length of time for the crankshaft to rotate between third and fourth angular positions; and misfiring sensing means for sensing misfiring of the engine based on a ratio of the lengths of the first and second periods. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A misfiring sensing apparatus for an engine equipped with a crankshaft comprising:
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acceleration determining means for calculating an instantaneous acceleration indicative of an angular acceleration of the crankshaft; and misfiring sensing means for sensing misfiring of the engine based on the calculated said instantaneous acceleration.
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18. A misfiring sensing method comprising:
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sensing a length of a first period equal to a length of time for the crankshaft of the engine to rotate between first and second angular positions; sensing a length of a different second period equal to a length of time for the crankshaft to rotate between third and fourth angular positions; calculating a ratio of the lengths of the first and second periods; and sensing misfiring based on the ratio. - View Dependent Claims (19, 20, 21, 22, 23)
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Specification