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

Claim 4:
5. The hydraulic system according to claim 1, further comprising:
a boom hydraulic cylinder supported by a base of the work machine via a cylinder body, and supported by the boom via a rod;
a boom first direction switching valve interposed between the first hydraulic pump and the boom hydraulic cylinder;
a boom second direction switching valve interposed between the second hydraulic pump and the boom hydraulic cylinder; and
a controller that controls an operation of the boom second direction switching valve when the boom hydraulic cylinder is retracted and operated,
wherein the boom first direction switching valve incorporates a boom regeneration passage capable of supplying oil discharged from a bottom chamber of the boom hydraulic cylinder to the rod chamber of the boom hydraulic cylinder when the boom hydraulic cylinder is retracted and operated, and
the controller monitors a pressure state of the boom hydraulic cylinder, and when determining that oil flow through the boom regeneration passage is possible, the controller blocks oil flow between the boom hydraulic cylinder and the boom second direction switching valve, and when determining that oil flow through the boom regeneration passage is not possible, the controller operates the boom second direction switching valve so that oil can be supplied from the second hydraulic pump to the rod chamber of the boom hydraulic cylinder.