Fluid cylinder with swivel joint
AssigneesKomatsu Ltd., Komatsu Zenoah Co.
InventorsTatsuya Futami, Yoshiaki Yamamoto, Kenji Kanemaru, Masatake Tamaru
Life of this patent
Estimating the term…
Abstract
A fluid cylinder with a swivel joint which is more improved with high utility is provided. To this end, in the fluid cylinder, a flow passage (R2b) leading to a chamber (1F) at the rod side of the cylinder is provided inside a rod (3), and a pin hole (3H) in a rod front end portion (3F) and a pin (P1) fitted in the pin hole (3H) are formed into a swivel joint so that the flow passage (R2b) is always guided to an outside even if the pin hole (3H) and the pin (P1) are relatively rotated.
Claims20
A fluid cylinder with a swivel joint comprising a cylinder tube, a piston fitted into said cylinder tube to be slidable in said cylinder tube, and a piston rod in which with a part at a rod front end portion side being protruded outside said cylinder tube and said piston being integrally fitted thereon, a protrusion amount of said part at the rod front end portion side to an outside of said cylinder tube is changed according to entrance and exit of fluid into and out of a chamber at a rod side and a chamber at a side opposite the rod inside said cylinder tube, an entire body being extended and contracted according to a change in said protrusion amount,
- said cylinder comprising a pin hole, into which a pin provided at another member is fitted, in at least one end portion of a tube rear end portion being an end portion at a side of said chamber at the side opposite said rod of said cylinder tube and said rod front end portion, and relative rotation of said cylinder tube around said pin is freely made during extension and contraction of the cylinder,
- said cylinder further comprising
- a first opening provided in an outer circumferential surface of said pin,
- a second opening, which is provided in an inner circumferenctial surface of said pin hole, and always opposes to said first opening even when said cylinder tube relatively rotates around said pin,
- a third opening provided in an end surface of said pin, and
- a swivel flow passage having a first flow passage provided inside said pin and leading from said first opening to said third opening, and a second flow passage leading from said second opening into said cylinder tube, in which said first flow passage and said second flow passage always communicate with each other via said first opening and said second opening even when said cylinder tube relatively rotates around said pin,
- wherein said pin provided with said first opening, said third opening and said first flow passage is a pin which is fitted in a pin hole of said rod front end portion, and
- wherein said second flow passage is provided inside said piston rod.
A fluid cylinder with a swivel joint comprising a cylinder tube, a piston fitted into said cylinder tube to be slidable in said cylinder tube, and a piston rod in which with a part at a rod front end portion side being protruded outside said cylinder tube and said piston being integrally fitted thereon, a protrusion amount of said part at the rod front end portion side to an outside of said cylinder tube is changed according to entrance and exit of fluid into and out of a chamber at a rod side and a chamber at a side opposite the rod inside said cylinder tube, an entire body being extended and contracted according to a change in said protrusion amount,
- said cylinder comprising a pin hole, into which a pin provided at another member is fitted, in at least one end portion of a tube rear end portion being an end portion at a side of said chamber at a side opposite said rod of said cylinder tube and said rod front end portion, and relative rotation of said cylinder tube around said pin is freely made during extension and contraction of the cylinder,
- said cylinder further comprising
- a first opening provided in an outer circumferential surface of said pin,
- a second opening, which is provided in an inner circumferenctial surface of said pin hole, and always opposes to said first opening even when said cylinder tube relatively rotates around said pin,
- a third opening provided in an end surface of said pin, and
- a swivel flow passage having a first flow passage provided inside said pin and leading from said first opening to said third opening, and a second flow passage leading from said second opening into said cylinder tube, in which said first flow passage and said second flow passage always communicate with each other via said first opening and said second opening even when said cylinder tube relatively rotates around said pin,
- wherein said second opening is provided in a relative rotation range of said cylinder tube around said pin in the inner circumferential surface of said pin hole.
Dependencies are inferred from the claim text.