PROXIMITY DETECTOR

PROBLEM TO BE SOLVED: To provide a proximity detector, capable of preventing false detection caused by rotation of a connecting member without using a plurality of magnetic sensors. SOLUTION: The proximity detector configured to be rotatable 300° in the circumferential direction with a relay pipe 20 being connected to a gas plug 10 and to detect whether a socket 30 is connected to the pipe 20 includes a magnet 500 provided on the socket 30 and capable of revolving with the rotation of the pipe 20 in a connecting state where the socket 30 is connected to the pipe 20; an inside yoke 200a provided on the plug 10 and facing an N-pole 510 in the connecting state; an outside yoke 200b provided on the plug 10 and facing an S-pole 520 in the connecting state; and a magnetic sensor 300 provided between the yokes 200a and 200b. The N-pole 510 is turned to the inside of the revolution, and the S-pole 520 is turned to the outside of the revolution. The yokes 200a and 200b have a circular arc shape substantially equal to the revolving route of the N-pole 510 and S-pole 520. COPYRIGHT: (C)2011,JPO&INPIT