Fluid pressure cylinder

A fluid pressure cylinder, comprising:

• a piston disposed displaceably in the interior of a cylinder tube;
• a piston rod connected to the piston;
• a first closure member for closing one end opening of the cylinder tube with the piston rod inserted therethrough;
• a second closure member inserted into another end opening of the cylinder tube for closing the other end opening;
• and
• a first port and a second port that open to the interior of the cylinder tube on an inner circumferential wall of the cylinder tube and through which a pressure fluid flows to move the piston along an axial direction of the cylinder tube,
• wherein a circular protrusion, which projects toward the piston along the axial direction of the cylinder tube, is formed on an inner end surface of the first closure member, wherein one of the first port and the second port is provided on the inner circumferential wall of the cylinder tube at a position along an axial direction which at least partly overlaps the position along an axial direction of the projection of the circular protrusion,
• a concavity, which can be fitted externally over the circular protrusion, is formed on the piston,
• an annular groove is formed on an inner circumferential edge of the second closure member, wherein the other of the first port and the second port is provided on the inner circumferential wall of the cylinder tube at a position along an axial direction which at least partly overlaps the position along an axial direction of the annular groove, wherein
• by the piston coming into contact with the second closure member, a pressure receiving chamber is formed between the piston and the annular groove, together with an opening of the second port on an inner side of the cylinder tube being closed by the piston to a maximum of 90%, and
• by the piston coming into contact with the circular protrusion, another pressure receiving chamber is formed between the piston and the first closure member, together with an opening of the first port on the inner side of the cylinder tube being closed by the piston to a maximum of 90%.