| 摘要 |
<p>PURPOSE:To make a self-retention type solenoid possible to secure high attraction and retention forces and also to be operated by a battery by such an arrangement wherein positioning parts are formed both in the central hole of a coil bobbin on which an electromagnetic coil is wound around and in a guide hole for a magnet holder so that the center of the bobbin coincides with that of the guide hole. CONSTITUTION:An electromagnetic coil 6 is wound around a coil bobbin 5 installed to the center of the bottom of a fixed iron core 1 of substantially U-like form having feet 3 symmetrically bent from the bottom. A pair of permanent magnet 9 are provided inside the feet 3 so that the same poles are symmetrically faced to each other and a movable iron core 17 is provided so that it is freely slidable piercing through the gap between magnets 9 and the central hole 7 of the coil bobbin. A magnet holder 10 is provided so that it holds the magnets 9 to make them contact with the internal surface of the feet 3, and positioning parts 8, 16 are formed both in the hole 7 and a magnet holder guide hole 11 so that the central axis of the hole 7 coincides with that of the guide hole 11. Thereby, the solenoid is less in the occurrence of leaking magnetic flux, has strong attraction and retention force and can be positively operated even by a power source such as a battery which is low in voltage has an upper limit for its current value.</p> |
