Shock absorbing device and suspension device

A shock absorbing device comprising:

• a rod configured to have a portion thereof inserted into a cylinder of a closed-end cylindrical shape including a bottom and a cylindrical portion;
• a first piston unit configured to be secured to the rod and to partition a space inside the cylinder;
• a collar of the closed-end cylindrical shape disposed at the bottom so as to open toward the first piston unit;
• and
• a second piston unit configured to be secured to the rod coaxially with the first piston unit, to enter the collar and to be capable of forming a high-pressure chamber within a space inside the collar, the high-pressure chamber being at a higher pressure than in a space closer to the first piston unit, wherein
• the second piston unit comprises:
• an elastic member of an annular shape having elasticity;
• a seal member disposed on a side opposite the first piston unit with respect to the elastic member in an axial direction of the rod, the seal member being configured to be capable of contacting an inner peripheral surface of the collar;
• and
• a restricting member configured to restrict movement of the elastic member and the seal member in the axial direction,
• the seal member comprises:
• a base portion of a cylindrical shape;
• and
• a projection protruding annularly toward the elastic member from an outer periphery of an opposing surface of the base portion, the opposing surface facing the elastic member, the projection being configured to be capable of contacting an outer periphery of the elastic member,
• the base portion includes a recess formed at a position inward of the projection, the recess being recessed from the opposing surface to a side opposite the elastic member, [and]
• the projection includes a groove formed in at least a portion thereof in a circumferential direction, the groove being configured to provide communication between inside and outside of the projection, and
• the shock absorbing device provides a flow path of a damping medium between the rod and the seal member, the flow path being connected to a space surrounded by the opposing surface of the seal member, an inner peripheral surface of the projection, and the elastic member.