Patent ID: 11927205
Assignee: KOMATSU LTD.
Field: Civil engineering (Other fields)
Classification: CPC F  E | IPC E  F

Claim 0:
1. A hydraulic system comprising:
an arm hydraulic cylinder supported by a boom of a work machine via a cylinder body, and supported by an arm of the work machine via a rod;
a first hydraulic pump and a second hydraulic pump;
an arm first direction switching valve interposed between the first hydraulic pump and the arm hydraulic cylinder;
an arm second direction switching valve interposed between the second hydraulic pump and the arm hydraulic cylinder; and
a controller that controls an operation of the arm second direction switching valve when the arm hydraulic cylinder is extended and operated,
wherein the arm first direction switching valve incorporates an arm regeneration passage capable of supplying oil discharged from a rod chamber of the arm hydraulic cylinder to a bottom chamber of the arm hydraulic cylinder when the arm hydraulic cylinder is extended and operated, and
the controller monitors a pressure state of the arm hydraulic cylinder, and when determining that oil flow through the arm regeneration passage is possible, the controller blocks oil flow between the arm hydraulic cylinder and the arm second direction switching valve, and when determining that oil flow through the arm regeneration passage is not possible, the controller operates the arm second direction switching valve so that oil can be supplied from the second hydraulic pump to the bottom chamber.