VARIABLE DAMPING FORCE SHOCK ABSORBER

摘要

PURPOSE:To contrive the improvement of durability with no consumption of useless driving energy by providing an expansion section exposed within a liquid hermetic chamber for one end of a valve body between both liquid chambers, and hermetically closing the opening of a sliding hole with the movement limit adapted opposite to the direction of the liquid hermetic chamber. CONSTITUTION:When the damping force of shock absorbers 41... is switched over, a valve body 73 and a spool valve 77 within a sliding hole crossing a communicating passage between No.1 and No.2 liquid pressure chambers 55 and 57 are moved upon applying pressure onto the liquid in a liquid hermetic chamber 71 by use of a driving source such as a piezo-stack 67FL and the like, following which an auxiliary flow channel 81 is communicated for lessening the damping force of a main piston 53. A disc section exposed within the liquid hermetic chamber 71 of the valve body 73 closes a gap at the opening of the sliding hole related with the valve body 73 during the aforesaid movement so as to prevent the liquid from leaking out of the liquid hermetic chamber 71 for maintaining the position and damping force of the valve body 73 while the piezo-stack 67FL is being operated. By to this constitution, an intake operation of working oil may be eliminated so as to consume no useless driving energy for enabling the improvement of the durability of the driving source.