Patent ID: 8590680
Filing Date: 2013-11-26
Classification: F16F

Abstract:
1. A shock absorber comprising: a cylinder in which a working fluid is enclosed; a piston slidably fitted into the cylinder and configured to partition an interior of the cylinder into two chambers; a piston rod configured to pass through the piston and being connected to the piston, the piston rod being configured to extend to an exterior of the cylinder; a first passage provided on the piston and into which the working fluid flows from one of the chambers of the interior of the cylinder by movement of the piston; a second passage provided inside the piston rod and into which the working fluid flows from one of the chambers of the interior of the cylinder by movement of the piston a damping valve installed on the first passage and configured to regulate a flow of the working fluid caused by sliding of the piston to generate a damping force; a back pressure chamber applying an internal pressure to the damping valve in a closing direction of the damping valve; a back pressure chamber inflow oil passage introducing the working fluid from the one of the chambers of the interior of the cylinder into the back pressure chamber; a housing in which at least a part of the second passage is located, the housing being located at a side of the other of the chambers of the interior of the cylinder with respect to the piston; a pressure chamber located inside the housing; and a free piston movably installed in the pressure chamber, wherein the second passage is configured to guide the working fluid from one of the chambers of the interior of the cylinder into the pressure chamber via a branch-off passage that branches off from the first passage and connects with the second passage provided inside the piston rod.