Abstract:
The present invention controls a proportional control valve controlling the maximum flow of the flow pump to perform controlling the maximum flow of the hydraulic oil pump after checking whether the pump joint control is normal, receiving a flow value of the flow pump controlled by the proportional control valve, checking an error when the flow value received during a control of the maximum flow has an error, and assigning a weight value to the checked error to compensate for the flow value. Therefore, the present invention may decrease a number of an engine revolution speed and lower a driving fuel consumption and reduce a driving noise.
Abstract:
A hybrid construction machine includes first and second main pumps, first and second supply passages, first and second circuit systems, a hydraulic motor, a motor generator, an assist pump, a joint passage connected to the assist pump and branched off, first and second logic valves, a switching valve disposed in the other branch passage and switchable to a state where the assist pump is connected to the second supply passage on the upstream side of the second logic valve and a state where the second main pump is connected to the hydraulic motor, and a check valve. A poppet diameter of the first logic valve is smaller than that of the second logic valve.
Abstract:
A hydraulic system (10), including fluid flow generated by a primary pump (14) and a secondary pump (16), utilizes a regulator control assembly (20) to control fluid flow from each of the primary and secondary pumps (14, 16) such that a desired fluid flow and pressure is maintained at the outlet (48) for varying actuator demands. The regulator control assembly (20) controls the transition from using only the primary pump (14), to using both the primary and secondary pumps (14, 16) to provide a desired fluid flow and pressure through the outlet (48) to an actuator (12).
Abstract:
A hydraulic system (10), including fluid flow generated by a primary pump (14) and a secondary pump (16), utilizes a regulator control assembly (20) to control fluid flow from each of the primary and secondary pumps (14, 16) such that a desired fluid flow and pressure is maintained at the outlet (48) for varying actuator demands. The regulator control assembly (20) controls the transition from using only the primary pump (14), to using both the primary and secondary pumps (14, 16) to provide a desired fluid flow and pressure through the outlet (48) to an actuator (12).
Abstract:
The present invention controls a proportional control valve controlling the maximum flow of the flow pump to perform controlling the maximum flow of the hydraulic oil pump after checking whether the pump joint control is normal, receiving a flow value of the flow pump controlled by the proportional control valve, checking an error when the flow value received during a control of the maximum flow has an error, and assigning a weight value to the checked error to compensate for the flow value. Therefore, the present invention may decrease a number of an engine revolution speed and lower a driving fuel consumption and reduce a driving noise.
Abstract:
The invention relates to a construction machine comprising a travel body (79), a swing body (13) swingably mounted onto said travel body (79), a boom (75), an arm (76), and a bucket (77) and a hydraulic drive system. The hydraulic drive system comprises a plurality of directional flow control valves (10a-f; 10a-h) including a boom, arm and bucket directional flow control valves, a boom inflow control valve (201), an arm inflow control valve (202), and a bucket inflow control valve (203). It is proposed that said boom inflow control valve (201), said arm inflow control valve (202) and said bucket inflow control valve (203) are provided only for the rod pushing-side chamber (5aA, 5bA) of a boom hydraulic cylinder (5a, 5b), the rod pushing-side chamber (6A) of an arm hydraulic cylinder (6) and the rod pushing-side chamber (7A) of a bucket hydraulic cylinder (7). Furhter, said plurality of directional flow control valves (10a-f; 10a-h) including the boom, arm and bucket directional flow control valves are disposed in said swing body,said boom inflow control valves (201), said arm inflow control valves (20) and said bucket inflow control valve (203) are all disposed together in one control valve unit (190), and said one control valve unit (190) is disposed on the upper surface of said boom (75).
Abstract:
A hydraulic drive system comprises directional flow control valves (10a-f) for selectively supplying a hydraulic fluid from a first hydraulic pump (1a, 1b), inflow control valves (201-203) disposed respectively in branch lines (150A-C) branched from a supply line (100) for supplying a hydraulic fluid delivered from a second hydraulic pump (3a, 3b) to rod pushing-side chambers (5aA, 5bA, 6A, 7A) of hydraulic cylinders, a bypass flow control valve (204) disposed in a line (104) connecting the supply line (100) and a reservoir (2), and a controller (31) for computing control variables corresponding to operation command signals from control levers (32, 33) and controlling the inflow control valves (201-203) and the bypass flow control valve (204) in accordance with the computed control variables. As a result, the number of flow control valves and the length of piping required for connection of the flow control valves can be further cut, and a total pressure loss can be further reduced. A reduction in the number of flow control valves contributes to simplifying layouts of hydraulic piping between hydraulic sources and actuators receiving hydraulic fluids from the hydraulic sources.
Abstract:
Hydrostatisches Antriebssystem mit mindestens einer mittels einer hydraulischen Einrichtung einstellbaren Pumpe, die in eine Förderleitung fördert, an die über je ein willkürlich betätigbares Schaltorgan mehrere Verbraucher anschließbar sind, wobei zu dem Zwecke, daß sich Änderungen des Druckes, die an einem Verbraucher durch Änderung von dessen Belastung entstehen, auf die anderen Verbraucher nicht auswirken, so daß jedem Verbraucher das Druckmittel mit dem für diesen Verbraucher erforderlichen Druck mit dem willkürlich gewählten Strom zufließt in jeder jeweils zu einem Verbraucher führenden Zweigleitung eine einstellbare Parallelschaltungsdrosselstelle angeordnet ist, deren Einstellorgan auf der einen Seite vom Druck in der Förderleitung 12 bzw. der Förderzweigleitung 28,82,104,105 und auf der anderen Seite von einem Steuerdruck und einer Feder beaufschlagt ist und wobei dieser Steuerdruck an allen Parallelschaltungsdrosselstellen gemeinsam ist und die von diesem beaufschlagte Seite des Einstellorganes über eine Steuerdruckzweigleitung 76, 77 an eine gemeinsame Steuerdruckleitung 80, 81, 83 angeschlossen ist, wobei in jeder Steuerdruckzweigleitung 76,78 ein zur gemeinsamen Steuerdruckleitung 80, 81, 83 hin öffnendes Rückschlagventil 79, 77 angeordnet ist.
Abstract:
Apparatuses and systems that use a variable displacement motor-pump (VDMP 110) to control the position and speed of a hose for an aerial refueling system are disclosed. At displacements greater than required to hold a position of the hose, the VDMP operates in a motor mode to retract the hose. For lesser displacements, the VDMP operates in a pump mode to control extension of the hose. In accordance with some embodiments, a pump-motor relief valve (112) operates to throttle hydraulic fluid flow from the VDMP and to control mixing of hydraulic fluid flowing from the VDMP with system hydraulic fluid.