Position displacement and speed sensor system, particularly for

Details Position displacement and speed sensor system, particularly for Position displacement and speed sensor system, particularly for

1986-06-13

1987-10-13

Lall, Parshotam S.

Boots, shoes, and leggings

123414, 123416, 36443105, F02P 508

Patent

active

047003057

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to a sensor to sense displacement or speed, typically displacement of a shaft, that is, its angular rotation, speed of the shaft, but may also be used as a sensor to determine linear displacement, and linear speed of one element with respect to another. The sensor is particularly adapted to determine the angular position of the crankshaft of an internal combustion engine--or of a shaft rotating in synchronism therewith, for example the camshaft--and the particular position of the shaft with respect to a reference, typically top dead enter (TDC) position of a predetermined one of a group of cylinders in a multi-cylinder internal combustion (IC) engine.


BACKGROUND

Ignition systems, and other control systems used in combination with internal combustion (IC) engines, such as fuel injection systems, and the like, utilize sensors which provide output signals characterizing the respective instantaneous position of the crankshaft or of the camshaft, respectively, of the engine. Two types of sensors are customarily used. One type is the incremental sensor. It is usually either a star disk, or a gear, for example the gearing of the starter gear, in which a plurality of projections or gear teeth are uniformly distributed with intermediate uniform gaps. The number of the teeth is counted, starting from a predetermined reference tooth. Any angular position of the crankshaft or the camshaft, respectively, can thus be determined by counting the teeth from the reference tooth. Thus, an ignition instant can be calculated to provide proper ignition timing for the IC engine. To provide a reference, the incremental sensors may use separate reference markers. It has also been proposed to provide a gear, in which one of the teeth is formed in a shape which differs from that of the others, so that, in this particular manner, a reference tooth can be characterized, that reference tooth then forming a reference marker. Such an arrangement is described in the German Patent Disclosure Document DE-OS No. 29 39 643.
In operation, incremental sensors operate satisfactorily. Upon starting, however, defining a predetermined ignition instant is possible only after some dead time has elapsed, which will depend on the position of the marker tooth when the engine was previously shut down with respect to a fixed sensor. Thus, counting of the teeth, and hence providing predetermined ignition signals, can commence only after the reference marker, or marker tooth, has passed the sensing element. In dependence on the instantaneous position of the reference marker, more or less time will elapse after re-starting of an engine until proper operation of the incremental sensor is possible.
Another type of sensor is the segmental sensor, in which a transducer disk is provided which carries a plurality of elongated segmental portions at the circumference thereof. The number of the segmental portions corresponds to the number of the cylinders of the internal combustion engine when the segments are secured to the camshaft of the engine. When the segments, or the segmental disk, are secured to the crankshaft of the engine, then the number of segments corresponds to half the number of cylinders, since the crankshaft, as is well known, rotates at half the speed of the camshaft. The segments cooperate with a fixed transducer element which senses the leading and trailing flanks of the segments to thereby sense the length of the respective segments. The leading flank of the segments customarily is shifted with respect to the position corresponding to the top dead center (TDC) position of the pistons of the IC engine. The ignition timing, thus, can readily be defined within the timing period determined by the length of the segments. No specific reference marker is needed for the segmental sensors in order to determine the ignition timing, since the segments are associated with respective cylinders.
For some purposes, it is desirable to provide a signal representative of a particular reference cylinder. Thus, it is also desirable

REFERENCES:
patent: 3696303 (1972-10-01), Hartig
patent: 3930201 (1975-12-01), Ackermann et al.
patent: 4181884 (1980-01-01), Shirasaki et al.
patent: 4322800 (1982-03-01), Hisegawa et al.
patent: 4356447 (1982-10-01), Honig et al.
patent: 4365602 (1982-12-01), Stiller et al.
patent: 4442822 (1984-04-01), Kondo et al.

Affiliated with

Also associated with

Rating

Position displacement and speed sensor system, particularly for does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Position displacement and speed sensor system, particularly for , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Position displacement and speed sensor system, particularly for will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-415572