| 摘要 |
<p>PURPOSE:To easily obtain the desired attracting force by matching the end surface of the inserting part of yoke piece within the through-hole of bobbin and making the side surface of inserting part into contact with pressure with the side surface of extra yoke. CONSTITUTION:An extra yoke 4 is formed by a bar type material having the square section, it is then inserted into a through-hole 2a of a bobbin 2 and both end portions are projected from the through-hole 2a. In the yoke 5, the internal surfaces of inserting portions 6a, 7a of the L-shaped yoke pieces 6, 7 are placed in contact with pressure with the side surface of the extra yoke 4, and the inserting portions 6a, 7a are cut away at the upper and lower end portions and narrowed. Moreover, since the extra yoke 4 of almost the same width is also provided along the yoke 5, the height does not increase even when a coil 3 is wound to the inserting portions 6a, 7a through the bobbin 2 and thereby an electromagnet device 1 can be formed thin. The desired attracting force can be attained without increase of magnetic resistance by compensating for the sectional area of the inserting portions 6a, 7a which are reduced by cutting away the extra yoke 4. If the extra yoke is formed by the material having higher permeability than that the material of yoke piece, the inserting portions of yoke piece can be more narrowed and a thinner electromagnet can be formed.</p> |
