Construction machine
AssigneeHitachi Construction Machinery Co., Ltd.
InventorsJuri SHIMIZU, Hajime OKANO, Kenji HIRAKU
Life of this patent
Estimating the term…
Abstract
An object of the present invention is to provide a construction machine that can suppress the lowering of the operability when a pressure sensor that measures the pressure of an actuator for driving a work device involves a failure in a case in which a closed circuit is formed between the actuator and a plurality of hydraulic pumps and the actuator is driven. For this purpose, when determining that an actuator pressure sensor involves a failure, a controller calculates pseudo-pressure of an actuator on the basis of a measurement value of a posture sensor, and calculates the differential pressure across a closed-circuit selector valve by using the pseudo-pressure instead of a measurement value of the actuator pressure sensor.
Claims6
A construction machine comprising:
- a work device;
- an actuator that drives the work device;
- a plurality of closed-circuit pumps of a variable displacement type having two flow-out/in ports;
- a plurality of closed-circuit selector valves capable of switching between communication and interruption between the actuator and the plurality of closed-circuit pumps;
- a posture sensor that senses posture of the work device;
- a plurality of closed-circuit pump pressure sensors that sense pressure of the plurality of closed-circuit pumps ;
- an actuator pressure sensor that senses pressure of the actuator;
- an operation device that instructs the actuator to act;
- and
- a controller that controls the plurality of closed-circuit selector valves and the plurality of closed-circuit pumps in response to an input signal from the operation device,
- the controller being configured to, when supply of a hydraulic operating fluid from one closed-circuit pump among the plurality of closed-circuit pumps to the actuator is started, open one closed-circuit selector valve corresponding to the one closed-circuit pump among the plurality of closed-circuit selector valves after controlling, in a state in which the one closed-circuit selector valve is closed, the one closed-circuit pump in such a manner that differential pressure across the closed-circuit selector valve that is a difference between a measurement value of one closed-circuit pump pressure sensor corresponding to the one closed-circuit pump and a measurement value of the actuator pressure sensor becomes equal to or lower than a predetermined first threshold, wherein
- the controller is configured to,
- in a state in which two or more closed-circuit pumps among the plurality of closed-circuit pumps are connected to the actuator, determine whether a failure of the actuator pressure sensor exists on a basis of measurement values of two or more closed-circuit pump pressure sensors corresponding to the two or more closed-circuit pumps among the plurality of closed-circuit pump pressure sensors and the measurement value of the actuator pressure sensor, and
- when determining that the actuator pressure sensor involves a failure, calculate pseudo-pressure of the actuator on a basis of a measurement value of the posture sensor, and calculate the differential pressure across the closed-circuit selector valve by using the pseudo-pressure instead of the measurement value of the actuator pressure sensor.
Dependencies are inferred from the claim text.