| 摘要 |
PURPOSE:To offer a small-sized magnetic proximity switch with high sensitivity and with optional directivity by providing a yoke except a magnetic sensitive part on the circumference of a magnetic sensitive element, also opening a part of the yoke to the circumference of the magnetic sensitive part, and providing a magnetism collecting part of the yoke in the rear of the magnetic sensitive part. CONSTITUTION:A Hall IC 3 is contained in a switch case 1, and a magnetic sensitive part 4 of the Hall IC 3 contacts by pressing so as to approach as near as possible an inside bottom face 5 of the switch case 1. A yoke 6 is a magnetic material; a magnetism collecting part 7 and an opening end 8 are formed on an intermediate part and both ends, respectively, the magnetism collecting part 7 abuts on the nearest rear face in the rear of the magnetic sensible part 4 of the Hall IC 3, and the opening ends 8, 8 are opened in the side face of the Hall IC 3. In this way, since the magnetism collecting part 7 abuts on the rear face of the magnetic sensitive part 4, a magnetic flux F of a permanent magnet M of a body to be detected, which arrives from a detecting part 2 direction of the switch case 1 is led to the opening ends 8, 8, passes through the yoke 6 and is focused to the magnetism collecting part 7, a magnetic flux density of this magnetism collecting part 7 goes to high density, a vertical distance (y) to be detected is lengthened, also directivity goes to sharp since a leakage magnetic flux decreases, and no malfunction is executed even in case of noise due to an external magnet.
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