CLAIMS
1. A fluid pressure cylinder (10, 100, 150) comprising:
a cylindrical cylinder tube (12) including an internal cylinder chamber (22);
a pair of cover members (14, 16, 102, 152) attached to both ends of the cylinder tube (12);
a piston (18) provided in a displaceable manner along the cylinder chamber (22); and
a piston rod (20) coupled to the piston (18),
wherein each of the piston (18) and the cylinder tube (12) is formed to have a rectangular shape in cross section;
the piston (18) includes a wear ring (52) configured to slide on an inner wall surface of the cylinder tube (12); and
a magnet (70) is provided in the wear ring (52).
2. The fluid pressure cylinder according to claim 1, wherein the magnet (70) is provided at a corner of the wear ring (52) having a rectangular shape in cross section.
3. The fluid pressure cylinder according to claim 1, wherein a piston packing (54, 92) having a rectangular shape in cross section in a form of a sheet is provided for the piston (18), and the piston packing (54, 92) is provided adjacent to the wear ring (52).
4. The fluid pressure cylinder according to claim 3, wherein a lubricant retention unit (76) is provided at an outer marginal portion of the piston packing (54, 92), and the lubricant retention unit (76) is in a form of a groove depressed in a thickness direction of the piston packing (54, 92).
5. The fluid pressure cylinder according to claim 4, wherein the lubricant retention unit (76) has an annular shape formed along the outer marginal portion.
6. The fluid pressure cylinder according to claim 1, wherein a sensor attachment rail (24) configured to attach a detection sensor for detecting magnetism of the magnet (70) is provided at a position adjacent to a corner of the cylinder tube (12) facing the magnet (70).
7. The fluid pressure cylinder according to claim 1, wherein the piston (18) is rotatably coupled to the piston rod (20).
8. The fluid pressure cylinder according to claim 1, wherein the piston (18) includes a coupling body (50) coupled to an end of the piston rod (20);
the coupling body (50) is partially placed inside the wear ring (52); and
a seal member is provided between the coupling body (50) and the wear ring (52).
9. The fluid pressure cylinder according to claim 3 or 4, wherein a packing hole (94) is formed at a center of the piston packing (92), and the piston (18) is configured to be outer marginal portion of the piston packing (54, 92), and the lubricant retention unit (76) is in a form of a groove depressed in a thickness direction of the piston packing (54, 92).
5. The fluid pressure cylinder according to claim 4, wherein the lubricant retention unit (76) has an annular shape formed along the outer marginal portion.
6. The fluid pressure cylinder according to claim 1, wherein a sensor attachment rail (24) configured to attach a detection sensor for detecting magnetism of the magnet (70) is provided at a position adjacent to a corner of the cylinder tube (12) facing the magnet (70).
7. The fluid pressure cylinder according to claim 1, wherein the piston (18) is rotatably coupled to the piston rod (20).
8. The fluid pressure cylinder according to claim 1, wherein the piston (18) includes a coupling body (50) coupled to an end of the piston rod (20);
the coupling body (50) is partially placed inside the wear ring (52); and
a seal member is provided between the coupling body (50) and the wear ring (52).
9. The fluid pressure cylinder according to claim 3 or 4, wherein a packing hole (94) is formed at a center of the piston packing (92), and the piston (18) is configured to be attached to the packing hole (94); and
the packing hole (94) has a rectangular shape corresponding to an outer shape of the piston packing (92).
10. The fluid pressure cylinder according to claim 9, wherein thickness of the piston packing (92) is decreased gradually from the center of the piston packing (92) toward the outer marginal portion of the piston packing (92).
11. The fluid pressure cylinder according to claim 1, wherein at least one of the cover members (102, 152) is provided detachably from the cylinder tube (12).
12. The fluid pressure cylinder according to claim 11, wherein the cylinder tube (12) and the cover member (152) are fixed through a tightening member (154).
13. The fluid pressure cylinder according to claim 11, wherein the cover member (102) is fixed to the cylinder tube (12) by a stopper member (104, 104a, 104b, 114a to 114d) configured to contact an end surface of the cover member (102) and to limit movement in an axial direction.