Abnormality detecting apparatus for means for sensing operating parameters of an internal combustion engine
First Claim
1. An abnormality detecting apparatus for detecting abnormality in operating parameter sensing means for sensing the value of an operating parameter of an internal combustion engine in synchronism with generation of pulses of a signal indicative of predetermined rotational angle positions of said engine, said apparatus comprising:
- comparator means for determining whether or not the detected value of said operating parameter lies outside a predetermined range which is a normal range of output of said operating parameter sensing means, that is capable of being produced when said engine is operating in a normal state;
first timer means responsive to results of said determination by said comparator means for measuring, when the detected value of said operating parameter lies outside said predetermined range, time elapsed from the instant at which the detected value of said operating parameter falls outside said predetermined range;
decision means for deciding that said operating parameter sensing means is faulty when the elapsed time measured by said first timer means exceeds a first predetermined period of time; and
second timer means disposed to be reset each time a pulse of said signal is generated for measuring time elapsed from the instant at which it becomes reset;
said second timer means being adapted to halt the measuring operation of said first timer means when the elapsed time measured by said second timer means reaches a second predetermined period of time which is shorter than said first predetermined period of time, whereby the detection of abnormality in said operating parameter sensing means is interrupted.
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Abstract
An abnormality detecting apparatus for detecting abnormality in sensing means for sensing a value of an operating parameter of an internal combustion engine in synchronism with generation of pulses of a signal indicative of predetermined rotational angle positions of said engine. When the sensed value of the operating parameter lies outside a predetermined range, first timer means measures time elapsed from the instant at which the sensed value of the operating parameter falls outside the predetermined range, and decision means decides that the operating parameter sensing means is faulty when the elapsed time measured by the first timer means exceeds a first predetermined period of time. Second timer means, which is reset each time a pulse of the above signal is generated, measures time elapsed from the instant at which it becomes reset, and is adapted to halt the measuring operation of the first timer means when the elapsed time measured by the second timer means reaches a second predetermined period of time which is shorter than the first predetermined period of time.
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Citations
6 Claims
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1. An abnormality detecting apparatus for detecting abnormality in operating parameter sensing means for sensing the value of an operating parameter of an internal combustion engine in synchronism with generation of pulses of a signal indicative of predetermined rotational angle positions of said engine, said apparatus comprising:
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comparator means for determining whether or not the detected value of said operating parameter lies outside a predetermined range which is a normal range of output of said operating parameter sensing means, that is capable of being produced when said engine is operating in a normal state; first timer means responsive to results of said determination by said comparator means for measuring, when the detected value of said operating parameter lies outside said predetermined range, time elapsed from the instant at which the detected value of said operating parameter falls outside said predetermined range; decision means for deciding that said operating parameter sensing means is faulty when the elapsed time measured by said first timer means exceeds a first predetermined period of time; and second timer means disposed to be reset each time a pulse of said signal is generated for measuring time elapsed from the instant at which it becomes reset; said second timer means being adapted to halt the measuring operation of said first timer means when the elapsed time measured by said second timer means reaches a second predetermined period of time which is shorter than said first predetermined period of time, whereby the detection of abnormality in said operating parameter sensing means is interrupted. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification