| 摘要 |
<p>PURPOSE: To correspond to a hoist load left as it is even when changed its weight while moving the hoisted cargo can be performed by light operating force. CONSTITUTION: An air supply circuit of supplying air to a lift cylinder 11 is provided with a weight memory pipe line 76 which can store an internal pressure of the lift cylinder 11 in a condition of holding a workpiece hung down, also to be provided with an operating valve 21 of performing supply/discharge action relating to the lift cylinder 11, addition pressure supply circuit 91 of supplying a pressure corresponding to slide resistance in the lift cylinder 11, subtraction pressure supply circuit 92, etc. When the hung down workpiece is up/down moved, the internal pressure of the lift cylinder 11 is changed, but by performing supply/discharge action against this change by the operating valve 21 to generate the internal pressure of the lift cylinder 11 so as to always balance with the workpiece while considering the sliding resistance, the workpiece is up/down moved by light operating force.</p> |
