Single-cylinder hydraulic shock absorber

A single-cylinder hydraulic shock absorber, comprising:

• a cylinder;
• a piston rod slidably moving out from an upper part of the cylinder into an exterior;
• and
• a flexible tubular member to form an air chamber connected air-tightly to the upper part of the cylinder and the piston rod respectively-and enclosing air therein, wherein:
• the flexible tubular member includes a lower end provided with a tubular protector engaged to the upper part of the cylinder;
• an inner periphery of an upper end of the protector includes a flexion part bent inside;
• the flexion part is retained on an upper end surface of the cylinder;
• a seal member is interposed between the flexion part and the upper end surface of the cylinder;
• the seal member includes a dust lip and an oil lip contacting on an outer periphery of the piston rod in an inner periphery side, and also a cored bar fixed on the upper end surface of the cylinder by caulking and a circular air seal interposed between the cored bar and the flexion part of the protector, so that the air seal prevents air inside the air chamber from leaking from an engagement clearance between the protector and the cylinder.