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US 8,225,706 B2Granted
Method for controlling a hydraulic cylinder and control system for a work machine
AssigneeVolvo Construction Equipment AB
InventorsBo Vigholm, Markku Palo
Life of this patent
Estimating the term…
Abstract
A method is provided for controlling a hydraulic cylinder, including detecting at least one operating parameter, and variably controlling a communication path between the piston-rod side and piston side of the hydraulic cylinder on the basis of the detected operating parameter.
Claims23
A method for controlling a hydraulic cylinder, comprising
- detecting a load acting upon the hydraulic cylinder,
- controlling opening and closing of a communication path between a piston-rod side and a piston side of the hydraulic cylinder based on the detected load, the piston-rod side and the piston side being connected to a hydraulic system via first and second lines, respectively, the first and second lines being connected by a third line, by opening and closing of a valve in the third line, the controlling comprising
- comparing a size of the detected load with a predetermined load level,
- closing the valve if the detected load exceeds the predetermined load level,
- opening the valve if the detected load is less than the predetermined load level, and
- continually variably controlling the communication path between the piston-rod side and piston side of the hydraulic cylinder.
3 more elements
A method for controlling a hydraulic cylinder, comprising
- detecting at least one operating, parameter,
- controlling opening and closing of a communication path between a piston-rod side and a piston side of the hydraulic cylinder based on the detected operating parameter,
- detecting an energy level in an energy storage means,
- comparing the detected energy level with a predetermined level, and
- restricting the communication path between the piston-rod side and piston side of the hydraulic cylinder if the detected energy level exceeds the predetermined level.
2 more elements
A control system for a work machine comprising
- at least one hydraulic cylinder comprising a piston defining a piston-rod side and a piston side of the cylinder,
- a hydraulic system, the piston-rod side and the piston side being connected to the hydraulic system via first and second lines, respectively, the first and second lines being connected by a third line,
- an openable and closable valve in the third line for controlling a communication path between the piston-rod side and the piston side of the hydraulic cylinder,
- a sensor arranged to detect a load acting upon the hydraulic cylinder, and
- a controller arranged to control opening and closing of the valve in response to the load detected by the sensor, the controller being arranged to compare a size of the detected load with a predetermined load level, close the valve if the detected load exceeds the predetermined load level, and open the valve if the detected load is less than the predetermined load level, the controller being arranged to continually variably control the communication path between the piston-rod side and piston side of the hydraulic cylinder.
2 more elements
Dependencies are inferred from the claim text.