Work machine
AssigneeKobelco Construction Machinery Co., Ltd.
InventorsYuki Miyoshi, Koji Ueda, Kosuke Yanagibashi
Life of this patent
Estimating the term…
Abstract
A work machine capable of preventing cavitation more effectively. The work machine includes a work device, a variable displacement hydraulic pump, a hydraulic actuator, a posture detector, a control valve, an operation unit, an operation detector, and a controller. The controller judges whether or not a work operation detected by the operation detector is a low-pressure operation based on posture information acquired by the posture detector, and increases the pump capacity of the hydraulic pump when judging that the work operation is the low-pressure operation.
Claims6
A work machine comprising:
- a work device;
- a pump unit including a first variable displacement hydraulic pump having a variable pump capacity and a second variable displacement hydraulic pump having a variable pump capacity;
- a hydraulic cylinder that is driven by hydraulic fluid supplied from the pump unit to actuate the work device, and has a first port, a second port, a head-side chamber communicating with the first port and a rod-side chamber communicating with the second port, the first port allowing hydraulic fluid to be flowed into and discharged from the hydraulic cylinder, the second port allowing hydraulic fluid to be flowed into and discharged from the hydraulic cylinder;
- a merging valve that allows hydraulic fluid discharged from the first variable displacement hydraulic pump and the hydraulic fluid discharged from the second variable displacement hydraulic pump to be merged with each other and supplied to the hydraulic cylinder,
- a posture detector that is configured to detect each of a head pressure, which is a pressure of the head-side chamber of the hydraulic cylinder, and a rod pressure, which is a pressure of the rod-side chamber of the hydraulic cylinder, and acquires posture information that is information about a posture of the work device based on the head pressure and the rod pressure;
- a control valve disposed between the pump unit and the hydraulic cylinder and configured to perform an action to change supply of hydraulic fluid from the pump unit to the hydraulic cylinder by being switched between a state of allowing the hydraulic fluid merged by the merging valve to be supplied to the head-side chamber and a state of allowing the hydraulic fluid merged by the merging valve to be supplied to the rod-side chamber;
- an operation unit that allows a work operation for making the control valve perform the action to be applied to the operation unit;
- an operation detector that detects the work operation applied to the operation unit;
- and
- a controller configured to determine whether or not the work operation detected by the operation detector is a low-pressure operation for making the control valve perform an action for allowing hydraulic fluid to be supplied to a hydraulic chamber having a lower pressure selected from the head-side chamber and the rod-side chamber, based on the posture information acquired by the posture detector,
- wherein the controller is configured to increase the pump capacity of at least one of the first variable displacement hydraulic pump and the second variable displacement hydraulic pump as a result of the determination that the work operation is the low-pressure operation based on the posture information acquired by the posture detector.
Dependencies are inferred from the claim text.