| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively attain a device that detects an absolute position of a rotor of a rotary valve.SOLUTION: A position detection device comprises: a position detection unit that has a position detection plate, and a plurality of sensors. The position detection plate is configured to rotate in conjunction with a rotor, and has a notch part at a circumferential part of a principal plane. The sensor is configured to detect presence or absence of the notch part at a plurality of positions on a rotation orbit of the notch part. The notch part of position detection plate and the sensor are designed so that a combination pattern of a detection signal of each sensor when the rotor is aligned with each position having an output port connected to an input port is all made different. Signal pattern data on the combination pattern of the detection signal of each sensor and the position of the rotor in the case of the combination pattern is held in a signal pattern holding unit. On the basis of the detection signal of each sensor and the signal pattern data, an absolute position of the rotor is detected.SELECTED DRAWING: Figure 1 |
