| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of impact even in the case of urgently stopping an operating means by forming a controller so as to output a zero value of the command current after lowering the command current to a target command current smaller than the initial value in the case where an operating speed is larger than the speed threshold value. SOLUTION: When an operating means (operating lever) 10 is operated, a controller 9 controls a proportional solenoid valve 8. When the operating speed of the operating lever 10 exceeds the speed threshold value, the proportional solenoid valve 8 is controlled on the basis on a time chart for urgent operation. In the case of operating the operating lever 10 toward a neutral condition at the operating speed more than the predetermined speed threshold value, the controller 9 reduces the command current to the target command current smaller than the initial current value, and reduces to zero. With this structure, since the command current is stopped after the flow of the hydraulic oil flowing in the proportional solenoid valve 8 is smoothly lowered to a value near zero, a lift cylinder can be smoothly stopped.
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