| 摘要 |
A shock absorber includes a suction passage (3) that only allows a flow from a reservoir (R) towards a pressure side chamber (R2), a rectifying passage (4) that only allows a flow from the pressure side chamber (R2) towards an expansion side chamber (R1), and a damping force variable valve (V) that only allows a flow from the expansion side chamber (R1) towards the reservoir (R). A large chamber (16), and a small chamber (15) and an outer peripheral chamber (17) are provided in a bottom member (11) serving as a housing so as to sandwich a free piston (5). The small chamber (15) communicates the outer peripheral chamber (17) with the expansion side chamber (R1). The large chamber (16) is communicated with the pressure side chamber (R2) through a first valve (Va) and a second valve (Vb). At the time of a contraction operation in which a piston (2) moves downward, even in a uniflow-type shock absorber in which pressure in the expansion side chamber (R1) becomes equal to that in the pressure side chamber (R2), the free piston (5) can move downward due to difference in pressure-receiving areas. Even if a stretching speed reaches a high speed range, the first valve (Va) and the second valve (Vb) are opened, and damping force is reduced. |
