Suspension apparatus

A suspension apparatus comprising:

• a cylindrical outer tube;
• an inner tube which is coaxially arranged inside the outer tube to move in an axial direction relative to the outer tube;
• a piston inserted into the inner tube;
• a piston rod of which one end portion retains the piston and which moves together with the outer tube with respect to the inner tube;
• a partition wall member that is mounted to an upper end portion of the inner tube to define an upper end portion of an annular oil chamber which is formed between an inner circumferential surface of the outer tube and an outer circumferential surface of the inner tube, that has a bowl portion formed into a bowl shape located inside the inner tube, and that divides a space inside the inner tube into an upper space which is a space above the bowl portion and a lower space which is a space below the bowl portion;
• a cap that covers an upper opening portion of the outer tube;
• and
• a support member of which one end portion is retained by the cap, and of which the other end portion supports the other end portion of the piston rod,
• wherein a through-hole is formed in a portion of the inner tube which is below the partition wall member to communicate the annular oil chamber with the lower space,
• an inner space of the piston rod is a space inside the piston rod and communicates with the lower space,
• the support member is a cylindrical member and forms an upper portion space between the cap and the support member, and the upper portion space communicates with the inner space of the piston rod,
• at least one of the cap and the support member is provided with a communication path through which the upper portion space communicates with the upper space,
• the cap has an abutting surface against which an upper end surface of the support member abuts, and
• the communication path comprises a non-return valve that is arranged between the abutting surface of the cap and the upper end surface of the support member such that air flows from the upper portion space into the upper space through the communication path, while the air is prevented from flowing from the upper space into the upper portion space, wherein the communication path is defined by a first concave section formed in a columnar portion of the cap and a second concave section formed in an inward portion of the cap.