摘要:
Hydraulic system for actuating the hydraulic actuators (2) of a working machine, the hydraulic system (1) has a delivery (3), a discharge (5), a drainage line (25), a signal line (21), a main slide valve (9) which actuates a corresponding hydraulic actuator (2), a safety slide valve (24) integral with the main slide valve (9) and adapted for opening or closing the drainage line (25) itself, and a pressure compensator (10) presenting a frontal chamber (13) connectable by way of the main slide valve (9) to the delivery (3) and a rear chamber (14) connected to the signal line (21); the drainage line (25) connecting a node (28) of the signal line (21) to the discharge (5).
摘要:
A valve for enabling the controls of a fluid-operated actuator, comprising a first body (2) that forms a longitudinal cavity (12) that has, at one end (2a), an inlet (13) for high-pressure fluid and at least one outlet (14) for discharging the fluid, a flow control element (22) that forms internally an axial cavity (26) and can move in the longitudinal cavity (12) between a position that opens the inlet (13) and a position that closes the inlet (13) and viceversa, a second body (3) that is connected hermetically to the other end of the first body (2) and has an extension (33) that is inserted hermetically in the axial cavity (26) and, on the opposite side with respect to the extension (33), a port (38) suitable to receive a pressurized actuation fluid for the actuation of a slider (44) that can move in a cylindrical seat (37) of the extension (33) between an inactive position and a stroke limit position, the flow control element (22) forming, with respect to the extension (33), a variable-volume pressurization chamber (48) and annular fluid transfer chambers (50,51,52) that are suitable to transfer the fluid that arrives from the inlet (13) toward the outlet (14), the pressurization chamber (48) and the transfer chambers (50,51,52) being detachably connected by the slider (44) in order to selectively move the flow control element (22) into the closure position, when the slider (44) is in the stroke limit position and the pressurization chamber (48) has the maximum volume, or into the open position, when the slider (44) is in the stroke start position and the pressurization chamber (48) has the minimum volume.
摘要:
A pressure-compensating directional control valve, particularly for actuating hydraulic actuators, of the type that comprises at least one modular valve body (2), which is affected by at least one through receptacle (3) for at least one shuttle (4) which can slide bidirectionally, by at least one driving fluid delivery port (14) connected to a pump, by at least one discharge port (15) for the fluid, by at least one first output-opening (16) and by a second output opening (17), which are connected respectively to the first chamber and to the second chamber of a hydraulic actuator, the shuttle (4) being controlled by remote operation means and being adapted to selectively connect the delivery port (14) to the first output opening (16) and the discharge port (15) to the second output opening (17) and vice versa, in the valve body (2) there being further at least one bridge (22) for the selective communication, by way of the shuttle (4), of the delivery port (14) with the first chamber or with the second chamber of the actuator, so as to actuate the actuator in one direction or the other; the valve further comprises at least one unidirectional hydrostat (23), which is connected to the bridge (22) by means of a supply duct (24) and is adapted to draw selectively a pressure signal of the load (LS) of the actuator, the signal (LS) being designed to adjust selectively the delivery pressure of the pump so as to keep substantially constant the pressure drop between the delivery port (14) and the actuator in any load condition.
摘要:
A hydraulic distribution unit (2) for controlling the actuation of a bush cutter, comprising a high flow-rate distribution unit associated with a rotary mower and a low flow-rate distribution unit associated with a positioning arm of the rotary mower; the distribution units have respective intake ducts (4,7) which are supplied by a high flow-rate pump and by a low flow-rate pump and respective discharges which lead into a common reservoir for collecting the oil; the distribution units are suitable to feed, by means of a pair of delivery manifolds (5,6), a motor for actuating the rotary mower and, by means of a series of pairs of delivery manifolds (8,9), a piston-type hydraulic servomechanism for mutually opposite movements of the positioning arm, the high flow-rate and low flow-rate distribution units being provided as a single body which has a first portion (2) dedicated to the actuation of the rotary mower and a second portion (3) dedicated to the actuation of the positioning arm.
摘要:
A hydraulic distribution unit (2) for controlling the actuation of a bush cutter, comprising a high flow-rate distribution unit associated with a rotary mower and a low flow-rate distribution unit associated with a positioning arm of the rotary mower; the distribution units have respective intake ducts (4,7) which are supplied by a high flow-rate pump and by a low flow-rate pump and respective discharges which lead into a common reservoir for collecting the oil; the distribution units are suitable to feed, by means of a pair of delivery manifolds (5,6), a motor for actuating the rotary mower and, by means of a series of pairs of delivery manifolds (8,9), a piston-type hydraulic servomechanism for mutually opposite movements of the positioning arm, the high flow-rate and low flow-rate distribution units being provided as a single body which has a first portion (2) dedicated to the actuation of the rotary mower and a second portion (3) dedicated to the actuation of the positioning arm.