| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance the reliability of lock operation for engaging a lock pin with the engaging portion of a gear, and to enhance durability of the lock pin.SOLUTION: A lock mechanism capable of locking and unlocking rotation of the rotor shaft 12 of an electric motor 11 is formed of a plurality of engaging holes 41 provided in the side face of one gear 33, out of a plurality of gears forming a reduction gear mechanism 13, in the circumferential direction thereof, lock pins 42 provided movably for the engaging holes 41, and locking the gear 33 by engaging with the engaging holes 41 when advancing, and a linear solenoid 43 for advancing and retreating the lock pin 42. The lock pin 42 is coupled with the plunger 47 of the linear solenoid 43 and integrated with the plunger 47. The lock pin 42 is formed of a nonmagnetic material, the magnetism of a magnetic circuit formed between the coil 45 of the linear solenoid 43 and the plunger 47 is prevented from leaking from the lock pin 42, and reliable attraction and movement of the plunger 47 is ensured by electrification of the coil 45 thus enhancing the reliability of lock operation.</p> |
