Cylinder tube, hydraulic cylinder with same, and method of manufacturing cylinder tube
AssigneeKomatsu Ltd.
InventorKouzou Yano
Life of this patent
Estimating the term…
Abstract
A cylinder tube of a hydraulic cylinder includes a substantially cylindrical outer peripheral wall portion, a port hole, and a plurality of rigidity changing portions. The port hole is formed in a part of the outer peripheral wall portion to communicate with an interior space of the outer peripheral wall portion. The rigidity changing portions are arranged at positions spaced at about 90 degrees leftward and rightward away from the port hole in the circumferential direction as viewed in section, with each of the rigidity changing portions having cross-sectional rigidity larger than a part in proximity to the port hole.
Claims15
A cylinder tube of a hydraulic cylinder comprising:
- a substantially cylindrical outer peripheral wall portion;
- a port hole that is formed in a part of the outer peripheral wall portion to communicate with an interior space of the outer peripheral wall portion;
- and
- a plurality of rigidity changing portions arranged at positions spaced at about 90 degrees leftward and rightward away from the port hole in the circumferential direction as viewed in section, with each of the rigidity changing portions having cross-sectional rigidity larger than a part in proximity to the port hole.
(canceled)
(canceled)
A method of manufacturing a cylinder tube of a hydraulic cylinder having a port hole, the method comprising:
- forming a flat plate-shaped material into a sectionally substantially semicircular member;
- arranging two of the sectionally substantially semicircular members to form a pipe-shaped member;
- coupling the sectionally substantially semicircular members arranged to form a pipe-shaped member to each other by welding;
- and
- forming the port hole at a position spaced in the circumferential direction away from parts of the substantially semicircular members coupled to each other by welding.
A method of manufacturing a cylinder tube of a hydraulic cylinder having a port hole, the method comprising:
- forming a steel tube by drawing;
- forming a rigidity changing portion at a predetermined position on the steel tube;
- and
- forming the port hole at a position on an outer peripheral surface of the steel tube spaced in the circumferential direction away from the rigidity changing portion.
Dependencies are inferred from the claim text.