摘要:
There is presented an on-off pilot stage valve arrangement (20) for controlling at least one main stage valve (9a, 9b, 9c, 9d). The on-off pilot stage valve arrangement comprises a first pilot valve (18) discretely operable between two states, an on and an off state, the first pilot valve having an input at which there is a first pressure and an output connected to the main stage valve, a second pilot valve (14) discretely operable between two states, an on and an off state, the second pilot stage valve having an input at which there is a second pressure and an output connected to said main stage valve. Both the valves are configured to be set in one of the two states in case the arrangement loses power.
摘要:
A hydraulic controller for working machine according to the present invention, which presupposes an electronic control system where an integrated bleed-off valve common to hydraulic actuators is used for bleed-off control and the bleed-off valve is controlled by the secondary pressure of a proportional solenoid valve controlled by a controller, is constituted to compensate supply of a pressure oil for the hydraulic actuators even if the secondary pressure of the proportional solenoid valve is stopped, by providing, at the bleed-off valve, a fail-safe position with a fail-safe path which opens with an opening having smaller area than an unload opening.
摘要:
A fail fixed actuator utilizing a rotary cam and servo are provided herein. A rod 10 comprises a piston 11 and a fluid channel 12 extending axially through the rod. A servo orifice 16 at a surface of the rod 10 is in fluid communication with the fluid channel 12. A cam 20 covers a portion of the rod 10 in close fitting relation, and comprises a groove 22. The servo orifice 16 and a portion of the groove 22 combine to form an aperture, movement of at least one of the cam 20 and rod 10 varying the size of the aperture. A piston chamber 13, containing the piston 11, comprises a high pressure chamber 14 and a servo pressure chamber 15, the servo pressure chamber being in fluid communication with the fluid channel 12.
摘要:
Valve means comprises cursor means (6) arranged for directing suitably a flow of a fluid material, proportional magnet means (35, 35a, 35b) arranged for moving said cursor means (6), electronic control means (3) for supplying said magnet means (35, 35a, 35b), said electronic control means (3) comprising switch means (54) arranged for blocking a supply of said magnet means (35, 35a, 35b); a method for supplying magnet means, said magnet means (35, 35a, 35b) being comprised in valve means (1), comprises processing an external enabling signal, said method comprising further processing an internal enabling signal, said internal enabling signal being generated by said valve means (1).
摘要:
Valve means comprises cursor means (6) arranged for directing suitably a flow of a fluid material, proportional magnet means (35, 35a, 35b) arranged for moving said cursor means (6), electronic control means (3) for supplying said magnet means (35, 35a, 35b), said electronic control means (3) comprising switch means (54) arranged for blocking a supply of said magnet means (35, 35a, 35b); a method for supplying magnet means, said magnet means (35, 35a, 35b) being comprised in valve means (1), comprises processing an external enabling signal, said method comprising further processing an internal enabling signal, said internal enabling signal being generated by said valve means (1).
摘要:
A method of operating a fail-fixed hydraulic actuator system (13) is provided. The method includes providing an actuator (40) in an initial position, electromechanically operating a valve assembly (30) to hydraulically drive actuator movement and halting the hydraulic driving of the actuator movement by the valve assembly (30).
摘要:
To provide a device (1) for providing a supply pressure for a consumer (8), having a main air system (2) which has a compressed air supply arrangement (3), a main air tank line (5) and a main air tank (4), and having an emergency pressure system (9) for generating the supply pressure independently of the main air system (2), wherein the main air system (2) and the emergency pressure system (9) can be connected independently of one another to the consumer (8), which device permits simple and reliable provision of the supply pressure, a storage tank (18) is proposed which is connected via a leak-free shut-off valve (20) to the main air system (2) or to the consumer (8), wherein the emergency pressure system (9) is connected at the outlet side to a dosing tank (17).