| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an electromagnet which can be produced at low cost by dispensing with pipes and caps included in a conventional electromagnet. SOLUTION: An electromagnet 1 has a hollow bobbin 5 with one end thereof closed by a rear wall 5a. A pair of coil accommodating walls 51 and 52 are formed at a front end and a middle part over the outer circumferential surface of the bobbin 5. A coil 7 is wound around the bobbin between the walls 51 and 52. A flange plate 53 is formed at the rear of the wall 52 via a clearance 5b, so that a lead 7a of the coil 7 is accommodated in the clearance 5b. The inner circumferential surface of the bobbin 5 includes a first fitting surface 55, with which a fixed core 9 is fitted and a second fitting surface 56 with which a movable core 11 is fitted. A surface 55 has a diameter larger than that of the surface 56. A plurality of rectangular oil grooves 57 are formed in the surface 56 in the axial direction, so that the grooves 57 allow oil to pass therethrough. Further, a stopper portion 54 is so formed on the wall 5a as to project inward, and the portion 54 thus contributes to reducing the contact surface with the core 11, when the core 11 comes in contact with the wall 5a.</p> |
