摘要:
In one aspect, a system for controlling the supply of hydraulic fluid to an implement of a work vehicle may generally include a pump, a control valve coupled to the pump and first and second fluid lines provided in flow communication with output ports of the control valve. The system may also include a pressure control valve provided in flow communication with the second fluid line that is configured to regulate a fluid pressure of the hydraulic fluid being supplied to a hydraulic cylinder of the implement. Additionally, the system may include a bypass fluid line configured to provide a flow path for hydraulic fluid between the pump and the second fluid line that is independent of the control valve and a load sensing line configured to provide an indication of the fluid pressure of the hydraulic fluid being supplied to the hydraulic cylinder.
摘要:
A method and apparatus for adaptively controlling a hydraulic press comprising a hydraulic drive unit for lifting and lowering a press ram. A piston chamber of the drive unit can be connected to a hydraulic accumulator formed by at least two groups of storage bottles, the connection established by hydraulic pipes that allows an expandable volume, stored in the storage bottles to supply the energy required for the press to perform a working stroke. Different filling pressures can be established in the storage bottles. A hydraulic accumulator can be adjusted to three operating modes, allowing a press controller to automatically analyze utilization and accordingly block individual groups or compartments of storage bottles, transfer the gas between storage bottles during a charging process at the end of the cycle, or adjust individual groups of storage bottles to different pressure levels. Advantageously, these three scenarios entail no waiting or transfer time.
摘要:
A hydraulic system is disclosed having first, second, and third pumps. The hydraulic system may also have a first actuator connected to the first pump in closed-loop manner, a second actuator connected to the second pump in closed-loop manner, and a third actuator. The hydraulic system may further have a selector valve associated with the third pump, and a first switching valve associated with the third pump and the third actuator. The first switching valve may be movable between a first position at which the third pump is connected to the third actuator in a closed-loop manner to move the third actuator in a first direction, a second position at which the third pump is connected to the third actuator in a closed-loop manner to move the third actuator in a second direction, and a third position at which the third pump is connected to the selector valve.
摘要:
A method is provided for recuperating potential energy during a lowering operation of a load, wherein a hydraulic system is adapted to lift and lower the load. In the method, at least two energy recuperation modes are provided, one of the modes is selected in response to a current operating state, and the hydraulic system is controlled according to the selected mode.
摘要:
A hydraulic circuit for operating a tool is provided that is particularly useful in construction equipment such as an excavator, crane, wheel loader, drilling machine, or others. Furthermore, a control unit and a method for controlling the hydraulic circuit and construction equipment including such a hydraulic circuit is disclosed.
摘要:
An agricultural implement system is provided that includes a valve in fluid communication with first and second actuating cylinders and with first and second fluid conduits. The valve is configured to control fluid flow from the first and second fluid conduits to the first and second actuating cylinders. Furthermore, a controller is communicatively coupled to first and second pressure sensors and to the valve. The first pressure sensor is coupled to the first fluid conduit, and the second pressure sensor is coupled to the second fluid conduit. The controller is configured to determine whether the first fluid conduit or the second fluid conduit is supplying fluid to the valve based on signals from the first and second pressure sensors, and to automatically control fluid flow to the first and second actuating cylinders such that wheel assemblies are rotated to a desired angle relative to an implement frame.
摘要:
A load sense connection is provided between the implement rockshaft cylinders and the load-sensed power source. However, to avoid tractor starting difficulty, a valve structure is provided in the power beyond fluid line to keep the fluid line closed when starting the tractor. This valve structure provides a hydraulic latching function that allows the load-sensed power source to be activated and deactivated depending on the SCV function. The load-sensed power source is activated when the rockshaft cylinder(s) is fully extended and remains activated or latched when the SCV is returned to neutral. The load-sensed power source is deactivated or unlatched when the rockshaft cylinder is retracted.
摘要:
Provided is a hydraulic drive including a double-acting work cylinder with a piston having a first working surface effective in a retracting direction and a second working surface effective in an extending direction, wherein the first working surface delimits a first pressure chamber and the second working surface delimits a second pressure chamber, at least two different pressures being applicable to at least one of the first working surface and the second working surface for retracting or extending the piston into and out of the work cylinder, an actuator unit which optionally enables a throttled return flow of a hydraulic medium from the first pressure chamber delimited by the first working surface, and control means for triggering the actuator unit in such a way prior to a sudden acceleration of the piston due to a sudden force release.
摘要:
The present disclosure relates to a hydraulic system for a construction machine which uses an electric hydraulic pump, and more particularly, to a hydraulic system including an emergency control unit for temporarily driving the construction machine when an electronic control unit controlling the electric hydraulic pumps fails to operate. To this end, disclosed is the hydraulic system including the electric hydraulic pump, the electric control unit for controlling the electric hydraulic pump, and the emergency control unit, which operates when the electric control unit fails to operate, so as to temporarily control the electric hydraulic pump in accordance with to a predetermined condition, which can effectively respond to a low load work corresponding to predetermined pressure and to a high load work corresponding to higher pressure, by selectively operating the emergency control unit according to different optional conditions, based on the amount of load (low load, high load) of the working machine that is required when the electric control unit fails to operate.
摘要:
A hydraulic system includes a variable displacement first pump, a first linear actuator fluidly connected to the first pump via a first closed-loop circuit, a variable displacement second pump, and second and third linear actuators fluidly connected to the second pump in parallel via a second closed-loop circuit. The system also includes a variable displacement third pump, a fourth linear actuator fluidly connected to the third pump via a third closed-loop circuit, a variable displacement fourth pump, and a first rotary actuator fluidly connected to the fourth pump via a fourth closed-loop circuit. The system further includes a second rotary actuator fluidly connected to the second pump in parallel with the second and third linear actuators. The system also includes a third rotary actuator fluidly connected to the third pump in parallel with the fourth linear actuator.