Patent ID: 11965315
Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Field: Civil engineering (Other fields)
Classification: CPC E  F | IPC E  F

Claim 0:
1. A work machine comprising:
a machine body;
a work device attached to the machine body;
an actuator that drives the machine body or the work device;
an operation device for giving an instruction on an operation of the actuator;
a hydraulic pump of a variable displacement type;
a pump regulator that controls a capacity of the hydraulic pump;
a hydraulic operating fluid tank that supplies a hydraulic operating fluid to the hydraulic pump;
a directional control valve that controls a flow of a hydraulic fluid to be supplied from the hydraulic pump to the actuator;
a bleed-off valve disposed on a flow line that connects a pump line of the hydraulic pump to the hydraulic operating fluid tank; and
a controller that controls the pump regulator, the directional control valve, and the bleed-off valve according to an input amount of the operation device, wherein
the controller is configured to
compute a target pump flow rate that is a target flow rate for the hydraulic pump, on a basis of the input amount of the operation device,
open the bleed-off valve at a timing at which the operation device is being operated and before the target pump flow rate starts increasing, and
close the bleed-off valve at a timing at which the operation device is being operated and after a flow rate of the hydraulic pump has started increasing.