STROKE DETECTION DEVICE

• Main Authors: ONOZUKA JUNJI, SHIMIZU SHINJI, AKIYAMA YOSHIYUKI, GORAI NOBUAKI
• Format: Patent
• Language: English; Japanese
• Published: 02.02.2015
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

PROBLEM TO BE SOLVED: To provide a stroke detection device which can be still more downsized without reducing detection accuracy.SOLUTION: A stroke detection device 4 according to the present invention includes: three magnetic substances 31, 32, 33 provided in a movement member 11; and magnetic flux density detection means 51A, 51B disposed at positions sequentially facing the magnetic substances 31, 32, 33 along with the movement of the movement member 11 and used for detecting the magnetic flux density of each of the magnetic substances 31, 32, 33. A first magnetic substance 31, a second magnetic substance 32, and a third magnetic substance 33 are disposed so that their magnetic poles are separated in a direction orthogonal to a movement direction 11, the first magnetic substance 31 and the second magnetic substance 32 are disposed so that the directions of their magnetic poles are opposite to each other, and the second magnetic substance 32 and the third magnetic substance 33 are disposed so that the directions of their magnetic poles are the same with each other. A clearance between the second magnetic substance 32 and the third magnetic substance 33 is smaller than a clearance between the first magnetic substance 31 and the second magnetic substance 32. 【課題】検出精度を低下させることなく、より小型化が可能なストローク検出装置を得ること。【解決手段】本発明のストローク検出装置４は、移動部材１１に設けられる３つの磁性体３１、３２、３３と、移動部材１１の移動により順次各磁性体３１、３２、３３に対向する位置に配置されて各磁性体３１、３２、３３の磁束密度を検出する磁束密度検出手段５１Ａ、５１Ｂとを有しており、第１磁性体３１と第２磁性体３２と第３磁性体３３は、移動方向１１に直交する方向に磁極が分かれて配置され、第１磁性体３１と第２磁性体３２は磁極の向きが互いに反対に配置され、第２磁性体３２と第３磁性体３３は磁極の向きが互いに同じに配置され、第２磁性体３２と第３磁性体３３との離間距離が第１磁性体３１と第２磁性体３２との離間距離よりも小さいことを特徴としている。【選択図】図４