| 摘要 |
PROBLEM TO BE SOLVED: To prolong the lifetime of a throttle valve position sensor by providing a magnetic part turning together with a gear secured to a throttle valve and detecting the flux density at the magnetic part thereby performing non-contact positional detection. SOLUTION: The throttle valve position sensor 70 being employed in internal combustion engine, and the like, comprises a magnet structure 69 consisting of magnetic parts 72, 74 being coupled with a gear 12 through arms 83, 85, and a flux density sensor, e.g. a Hall effect sensor 90. The magnetic parts 72, 74 composed of a magnetic body of coupling ferrite, or the like, has an arcuate structure where the thickness varies gradually between wide and narrow end parts. The facing surfaces of the magnetic parts 72, 74 recede from each other as the magnetic parts 72, 74 become thinner and a field varying along the circumferential direction of the magnetic parts 72, 74 is generated. The gear 12, and thereby a valve shaft 6, can thereby be located by means of the sensor 90 disposed in the air gap 100 between the magnetic parts 72, 74.
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