Abstract: In a hydraulic cylinder having a shock absorbing function, and capable of stopping as desired by an accumulator disposed within a cylinder rod. The accumulator includes an accumulator piston that divides the cylinder rod interior into first and second cylinder rod chambers, gas hermetically charged into the second cylinder rod chamber, and an accumulation port that is communicated with the first cylinder rod chamber and flows the operating oil from outside into the first cylinder rod chamber.

Abstract: A hydraulic circuit for a hydraulic cylinder capable of executing and adjusting a shock absorbing function at the time of stopping the operation of a cylinder piston rod and releasing the function, comprises a damping control valve (v1) having a first switching position (v11) which blocks the connection of the accumulation port (22) with outside and performs supply and discharge or discharge and supply of the operating oil with respect to the first cylinder chamber (3) and the second cylinder chamber (4), a second switching position (v12) connecting at least the accumulation port (22) and the second cylinder chamber (4), and a third switching position (v13) connecting at least the accumulation port (22) and the first cylinder chamber (3).

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.

Abstract: A hydraulic circuit for a hydraulic cylinder capable of executing and adjusting a shock absorbing function at the time of stopping the operation of a cylinder piston rod and releasing the function, comprises a damping control valve (v1) having a first switching position (v11) which blocks the connection of the accumulation port (22) with outside and performs supply and discharge or discharge and supply of the operating oil with respect to the first cylinder chamber (3) and the second cylinder chamber (4), a second switching position (v12) connecting at least the accumulation port (22) and the second cylinder chamber (4), and a third switching position (v13) connecting at least the accumulation port (22) and the first cylinder chamber (3).

Abstract: In a hydraulic cylinder having a shock absorbing function, and capable of stopping as desired by an accumulator disposed within a cylinder rod, the accumulator comprises an accumulator piston that divides the cylinder rod interior into first and second cylinder rod chambers, gas hermetically charged into the second cylinder rod chamber, and an accumulation port that is communicated with the first cylinder rod chamber and flows the operating oil from outside into the first cylinder rod chamber.

Abstract: A hydraulic pipe arrangement of a working machine is not in contact with an obstacle and no torsion and no bending are generated. Accordingly, in a hydraulically driven type working machine provided with a boom (1) having a vertical swing supporting point supported at a base end side by a machine frame and a joint connection supporting point in a front end side, an arm (2) connected in a base end side to the joint connection supporting point, a boom driving hydraulic cylinder (6a) hoisting around a hoist supporting point provided in the machine frame so as to drive the boom, an arm driving hydraulic cylinder (7), and a working tool driving hydraulic cylinder (8), a swivel joint mechanism relaying a hydraulic pipe arrangement from a side of the machine frame is provided at a center of at least one of the vertical swing supporting point, the joint connection supporting point and the boom driving hydraulic cylinder hoist supporting point.

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.

Abstract: A hydraulic pipe arrangement of a working machine is not in contact with an obstacle and no torsion and no bending are generated. Accordingly, in a hydraulically driven type working machine provided with a boom (1) having a vertical swing supporting point supported at a base end side by a machine frame and a joint connection supporting point in a front end side, an arm (2) connected in a base end side to the joint connection supporting point, a boom driving hydraulic cylinder (6a) hoisting around a hoist supporting point provided in the machine frame so as to drive the boom, an arm driving hydraulic cylinder (7), and a working tool driving hydraulic cylinder (8), a swivel joint mechanism relaying a hydraulic pipe arrangement from a side of the machine frame is provided at a center of at least one of the vertical swing supporting point, the joint connection supporting point and the boom driving hydraulic cylinder hoist supporting point.