Nippondenso Co., Ltd.

Masahiro Sato

Akihiko Takenaka

Miyao Arakawa

Kunio Makita

Hiroo Utsumi

Shingo Inoue

Toshiyuki Yamaguchi

Hideo Ohyama

A rotational position detecting apparatus for an internal combustion engine comprises a first and a second signal generator each thereof having a signal rotor rotating in synchronism with the rotation of the engine, a first and a second waveform reshaping circuit and a signal processing circuit. Engine rotational angle signals produced by the first signal generator and engine cylinder reference angular position signals and a specified cylinder angular position signal produced by the second signal generator are reshaped through the first and second waveform reshaping circuits, respectively, and both output signals from the first and second waveform reshaping circuits are supplied to the signal processing circuit. The signal processing circuit separates the reference signals and the cylinder discrimination signal from the output signals of the second waveform reshaping circuit and outputs the separated signals along with the angle signals produced by the first waveform reshaping circuit. This rotational position detecting apparatus for internal combustion engines is featured in that it is simple in construction and small in size and its operation is hardly susceptible to interference caused by radio noise.

Rotational position detecting apparatus for internal combustion engines

A rotation detecting apparatus includes a first electromagnetic pickup of the electromagnetic coil type positioned to face a single signal rotor in the diametrical direction thereof and generate a first rotation signal, a permanent magnet received in a recess formed in the principal plane surface of the signal rotor, and a second electromagnetic pickup including a magnetoresistance effect element positined separately above the upper surface of the permanent magnet and operatively associated with the magnet to generate a second rotation signal.

Electromagnetic rotation detecting apparatus

A rotational position detecting apparatus includes a rotating member magnetized to induce a large number of magnetic poles on the periphery thereof except at a portion indicative of a rotational reference position, and a pair of magnetically sensitive elements for detecting the magnetic flux from the magnetic poles so as to generate rotational angle signals and reference position signals. The pair of magnetically sensitive elements are positioned side by side such that their output signals generated in response to the magnetic flux from the magnetic poles are different in phase by half the period, and the difference between the outputs of the magnetically sensitive elements is obtained by a differential circuit whose output has an amplitude which is two times the amplitude of the outputs of the magnetically sensitive elements. The magnetic poles on the periphery of the rotating member are dropped out at the reference position in such a manner that the output AC component of the respective magnetically sensitive elements is dropped out at the reference position in a point symmetrical manner on both sides of the zero level of the AC component, thus stably supplying the rotational angle signals and the reference position signals.

Rotational position detecting apparatus

This invention discloses a rotational position detecting apparatus for an internal combustion engine for detecting the rotational position of a crank shaft of the engine. The apparatus comprises a rotating disk driven by the engine and giving a large number of angular information signals and also a rotating disk having one reference information on the periphery thereof, an angle sensor for detecting the angular informations on the disk, a rotational reference sensor for detecting the reference information on the disk, waveform reshaping circuits for reshaping the output signals of said both sensors, and an electric circuit for determining the angular position and the reference position from the outputs of said waveform reshaping circuits, wherein a logical product of the reshaped output of the angle sensor and the reshaped output of the reference sensor is implemented, and the time of either one of the rise or fall of an output signal of the logical product is set to be an angular position, while the other one is set to be a reference position.

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Toyoake, Japan

Masahiro Sato