| 摘要 |
PROBLEM TO BE SOLVED: To reduce a spring constant without extending the total length of a coil spring and to achieve miniaturization by elastically connecting a cylinder and a piston inserted into the cylinder, and providing the coil spring arranged to surround part of the cylinder face and part of the piston. SOLUTION: A cylindrical through hole 19 is formed on a yoke 5 made of structural carbon steel, and pistons 7 are inserted into cylindrical cylinder sleeves 20 fitted into the through hole 19 from both end sides, thereby a compression chamber 4 sandwiched by the right and left pistons 7 is demarcated nearly at the center of the through hole 19. Annular grooves 3 surrounding the through hole 19 are formed on both end faces of the yoke 5, and annular permanent magnets 17 are fitted to the outer peripheral side faces of the grooves 3. A coil bobbin 30 wound with a moving coil 16 is inserted into the permanent magnet 17 in each annular groove 3, and the coil bobbin 30 is reciprocated by energization control to reciprocate the piston 7 against a coil spring 8.
|
