摘要:
A construction machine includes: a swing structure (20); hydraulic and electric motors (25) mechanically coupled to each other; a hydraulic pump (41) that supplies hydraulic fluid to the hydraulic motor; swing control lever (72) that instructs the swing structure to make a swing motion; and a control device (80) that controls at least either a delivery flow rate of the hydraulic pump or an output torque of the electric motor in such a manner that meter-out and meter-in pressures of the hydraulic motor that is run together with the electric motor approach each other when the demanded torque necessary for the swing motion of the swing structure instructed by the swing control lever can be produced by the electric motor alone.
摘要:
A hydraulic system and a method comprising a linear actuator 23 for generating discrete sum forces, chambers A-D for generating discrete force components, at least two charging circuits 3,4 configured to maintain predetermined pressure levels of hydraulic fluid, independent control interfaces 9-16 configured to open and close connections of the first and second charging circuits to the chambers, and an electronic control unit 50 for controlling the control interfaces. At least two control interfaces are proportional valves which are used as shut-off valves and are independently switchable to the open and closed positions in a controlled manner. Moreover, non-throttled control and secondary control are implemented in the hydraulic system and the method.
摘要:
Mit einer fluidischen Steuerung (10,302,402) ist durch Fußschalter jeweils mindestens ein Fluidikzylinder (304,404,310,410) , z. B. eines Probenhalters, oder ein Aktuator einer Prüfmaschine in einem Tippbetrieb verfahrbar, indem eine fluidische Druckverbindung auf eine Seite eines Kolbens (308,309) in dem Fluidikzylinder durch ein Ventil (114,214,314,414,115,315,415), das wenigstens zwei Stellungen umfasst, hergestellt wird. Ein Zweistellungswechselventil (112,312,412,113,313,413) der Steuerung dient dazu, in einer vorgegebenen Stellung des Ventils bzw. des Fußschalters selbsttätig durch die Steuereinheit einen zweiten Zustand einzunehmen, in dem ein fluidisch betätigtes Hauptdruckfreischaltventil (124,324,424,125,325)das Zweistellungswechselventil in einen Hauptdruckbetrieb schaltet, sodass der Fluidikzylinder mit einem höheren Druck gehalten ist. In einer weiteren Position des Fußschalters wird ein Entlastungsventil (122, 322, 422, 123, 323, 423; 114, 314, 414, 115, 315, 415) betätigt, das den Hauptdruck zum Halten freigibt und unter Nutzung eines Drucks, der größer oder gleich dem Hauptdruck ist, den Fluidikzylinder schnell zurückfährt.
摘要:
A hydraulic system includes a first and a second rotating hydraulic machine, the first and second hydraulic machine being arranged to provide a torque via a common output shaft; a first valve arrangement for providing a differential hydraulic pressure level over the first hydraulic machine by using two sources of hydraulic fluid having different hydraulic pressure levels, a second valve arrangement for providing a differential hydraulic pressure level over the second hydraulic machine by using two sources of hydraulic fluid having different hydraulic pressure levels; and a control unit configured to control the first valve arrangement and the second valve arrangement such that different discrete levels of torque are provided via the output shaft of the hydraulic system. A hydraulic system for providing different discrete levels of torque using one hydraulic machine and a plurality of differential pressure levels, and a method for controlling a hydraulic system, are also provided.
摘要:
A hydraulic system includes a first and a second rotating hydraulic machine, the first and second hydraulic machine being arranged to provide a torque via a common output shaft; a first valve arrangement for providing a differential hydraulic pressure level over the first hydraulic machine by using two sources of hydraulic fluid having different hydraulic pressure levels, a second valve arrangement for providing a differential hydraulic pressure level over the second hydraulic machine by using two sources of hydraulic fluid having different hydraulic pressure levels; and a control unit configured to control the first valve arrangement and the second valve arrangement such that different discrete levels of torque are provided via the output shaft of the hydraulic system. A hydraulic system for providing different discrete levels of torque using one hydraulic machine and a plurality of differential pressure levels, and a method for controlling a hydraulic system, are also provided.
摘要:
A linear actuator system includes a linear actuator and at least one integrated pump assembly connected to the linear actuator to provide fluid to operate the linear actuator. The integrated pump assembly includes a pump with at least one fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to exclusively adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.
摘要:
The invention relates to a screw system for carrying out screwing operations, in particular automatically, with a screwing tool and a feed device having a pneumatic feed cylinder by means of which the screwing tool is movable in a feed direction in order to be brought into engagement with a screw and to drive the latter into components to be screwed together with a first feed force during a screwing operation.
摘要:
When used for an electrically-operated hydraulic work machine that drives an actuator with a hydraulic pump driven by an electric motor and exercises load sensing control by controlling the rotation speed of the electric motor, the present invention increases the useful life of an electrical storage device, which is an electrical power source for the electric motor, by suppressing the horsepower consumption of the hydraulic pump, prolongs the operating time of the electrically-operated hydraulic work machine, and reduces the size of the electric motor. The present invention uses a controller 50 to exercise load sensing control over a variable displacement main pump 2 by controlling the rotation speed of the electric motor 1, and provides the main pump 2 with a torque control device 17 that reduces the delivery rate of the main pump 2 when the delivery pressure of the main pump 2 increases, or provides the controller 50 with a control algorithm that performs the same function as the torque control device 17.