Detection apparatus and control apparatus

Patent metadata

Field	Value
Publication number	US-11512676-B2
Application number	US-202117209511-A
Country	US
Kind code	B2
Filing date	Mar 23, 2021
Priority date	Mar 31, 2020
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

A detection apparatus for detecting a cam angle of a 4-stroke multi-cylinder engine in which explosion intervals are unequal intervals, includes a detection target member configured to rotate in synchronism with a camshaft, and first and second cam angle sensors configured to detect rotation of the detection target member. The detection target member includes a plurality of first detection target portions arranged, at equal pitches, as many as the number of cylinders of the multi-cylinder engine. The second cam angle sensor is arranged while being shifted in the rotation direction with respect to the first cam angle sensor such that any one of detection signals of the plurality of first detection target portions by the first cam angle sensor and the second cam angle sensor is output at a timing corresponding to each explosion interval.

First claim

What is claimed is:

1. A detection apparatus for detecting a cam angle of a 4-stroke multi-cylinder engine in which explosion intervals are unequal intervals, comprising:
a detection target member configured to rotate in synchronism with a camshaft;
a first cam angle sensor configured to detect rotation of the detection target member so as to output a detection signal as a reference ignition timing signal for an advance or retard ignition timing; and
a second cam angle sensor configured to detect rotation of the detection target member so as to output a detection signal as the reference ignition timing signal;
wherein the detection target member includes a plurality of first detection target portions for ignition timings arranged, at equal pitches, as many as the number of cylinders of the multi-cylinder engine in a rotation direction of the detection target member, and
the second cam angle sensor is arranged while being shifted in the rotation direction with respect to the first cam angle sensor such that any one of detection signals of the plurality of first detection target portions by the first cam angle sensor and the second cam angle sensor is output as the reference ignition timing signal at a timing corresponding to each explosion interval of the explosion intervals.

2. The apparatus according to claim 1 , wherein the detection target member includes a second detection target portion that is adjacent to one of the plurality of first detection target portions and corresponds to a position of a piston of a specific cylinder.

3. The apparatus according to claim 1 , wherein if an angle concerning a greatest common divisor of the explosion intervals is set as ϕ in terms of a crank angle,
the second cam angle sensor is arranged while being shifted in the rotation direction with respect to the first cam angle sensor such that detection signals of the plurality of first detection target portions by the second cam angle sensor have a phase difference of ϕ/2 in terms of the cam angle with respect to detection signals of the plurality of first detection target portions by the first cam angle sensor.

4. The apparatus according to claim 3 , wherein the second cam angle sensor is arranged while being shifted, with respect to the first cam angle sensor, by ϕ/2 in the rotation direction from a position shifted by 180° in terms of the cam angle.

5. A control apparatus of a 4-stroke multi-cylinder engine in which explosion intervals are unequal intervals, comprising:
the detection apparatus according to claim 1 ;
a crank angle sensor; and
a control unit configured to control an ignition timing based on two detection results of the first cam angle sensor and the second cam angle sensor provided in the detection apparatus and the crank angle sensor.

6. The apparatus according to claim 5 , wherein the control unit
controls the ignition timing based on the detection results of the first cam angle sensor and the second cam angle sensor at a start of the multi-cylinder engine, and
controls the ignition timing based on the detection result of one of the first cam angle sensor and the second cam angle sensor and the detection result of the crank angle sensor after the start of the multi-cylinder engine.

7. The apparatus according to claim 5 , wherein if a failure occurs in one of the first cam angle sensor, the second cam angle sensor, and the crank angle sensor, the control unit controls the ignition timing based on remaining two sensor's detection results.

8. The apparatus according to claim 5 , wherein the multi-cylinder engine is an outboard engine.

9. The apparatus according to claim 1 , wherein the engine includes six cylinders, and the detection target member includes six first detection target portions.

10. The apparatus according to claim 1 , wherein the engine includes eight cylinders, and the detection target member includes eight first detection target portions.

Assignees

• Honda Motor Co Ltd

Inventors

• Fujima Akifumi
• Miyashita Kazumi

Classifications

• F02P5/15

  Digital data processing · CPC title

• F02P5/1502 Primary

  using one central computing unit · CPC title

• F02D41/009

  using means for generating position or synchronisation signals · CPC title

• F02B61/045

  for marine engines · CPC title

• F02B2075/027

  four · CPC title