| 摘要 |
<p>PURPOSE:To obtain a uniform attracting force even at a long stroke in an electromagnetic device by forming a hole of small diameter at one end of a yoke forming a solenoid in a cavity, forming an opening at the other end of the yoke, and forming the shape of a plunger surrounded by electromagnetic coil inserted thereinto the size thereof is large at the opening and small toward the hole. CONSTITUTION:A cylindrical yoke 10 having a cavity is reduced at one end with a hole 10a of small diameter and is opened at the other end with a large-diameter hole 10b. Then, a plunger 12 to be inserted into the yoke 10 is also formed at the large hole 10b with a large diameter part 12b to block the hole and formed at the end of the small-diameter hole 12a to be inserted into the yoke 10 with slightly smaller than the hole 10a of the yoke 10. Then, an electromagnetic coil 14 surrounding the small-diameter part 12a of the plunger 12 is formed in the vicinity of the hole 10a side as a solenoid. Thus, a current flowed to the coil 14 is controlled to telescope the plunger 12 at the small diameter part 12a into the hole 10a, thereby varying the magnetic flux in the closed magnetic path to equalize the attracting force.</p> |
