Hydraulic system for work machine, work machine, and method for controlling hydraulic system
AssigneeKomatsu Ltd.
InventorsKiyotaka Ninomiya, Koji Sato, Takuya Higashiura, Yuji Fukuda, Akihiro Koyama
Life of this patent
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Abstract
A coupler cylinder is driven between a locked state and an unlocked state of a bucket by being supplied with hydraulic oil. A main pump supplies the hydraulic oil to the coupler cylinder. A pressure increasing valve controls the supply of the hydraulic oil to the coupler cylinder. A controller controls drive of the pressure increasing valve. The controller instructs the pressure increasing valve to stop the supply of the hydraulic oil to the coupler cylinder based on pressure in an oil passage between the main pump and the coupler cylinder.
Claims8
A hydraulic system for a work machine comprising:
- a coupler cylinder that is driven between an extended position and a retracted position by being supplied with oil;
- a hydraulic pump that supplies the oil to the coupler cylinder in order to drive the coupler cylinder between the extended position and the retracted position;
- a valve that controls the supply of the oil to the coupler cylinder;
- and
- a controller that controls drive of the valve,
- wherein the controller instructs the valve to stop the supply of the oil to the coupler cylinder based on pressure in an oil passage between the hydraulic pump and the valve, and
- wherein oil having a pressure greater than or equal to a predetermined value is supplied to the coupler cylinder while the coupler cylinder is fixed at each of the extended position and the retracted position.
A work machine comprising:
- a machine body;
- an attachment that is capable of switching between a locked state and an unlocked state with respect to the machine body;
- a coupler cylinder that is driven between the locked state and the unlocked state of the attachment by being supplied with oil;
- a hydraulic pump that supplies the oil to the coupler cylinder;
- a valve that controls the supply of the oil to the coupler cylinder;
- and
- a controller that controls drive of the valve,
- wherein the controller instructs the valve to stop the supply of the oil to the coupler cylinder based on pressure in an oil passage between the hydraulic pump and the valve, and
- wherein oil having a pressure greater than or equal to a predetermined value is supplied to the coupler cylinder while the coupler cylinder is fixed at each of the locked state and the unlocked state.
A method for controlling a hydraulic system in a work machine including a coupler cylinder that is driven between an extended position and a retracted position by being supplied with oil, a hydraulic pump that supplies the oil to the coupler cylinder in order to drive the coupler cylinder between the extended position and the retracted position, and a valve that controls the supply of the oil to the coupler cylinder, the method comprising:
- detecting pressure in an oil passage between the hydraulic pump and the valve;
- and
- outputting a supply stop signal of the oil to the coupler cylinder to the valve based on the detected pressure,
- wherein oil having a pressure greater than or equal to a predetermined value is supplied to the coupler cylinder while the coupler cylinder is fixed at each of the extended position and the retracted position.
Dependencies are inferred from the claim text.