| 摘要 |
<p>PURPOSE: To stabilize an operation with a simple structure by stopping one of two cylinders by closing a check valve, elongating/contracting the other on priority basis, and forcibly opening the valve to operate the other cylinder when the preceding cylinder reaches a stroke end. CONSTITUTION: For cylinder elongation, the discharge pressure of a hydraulic pump 1 causes a first cylinder 4 to be elongated by the action of a check valve 45 opened toward the piston head side room 25 of the first cylinder 4. During this period, by the actions of third and fourth check valves 15 and 41 opened in directions opposite the flowing direction of pressure oil for the elongation of a second cylinder 5, an opening/closing switching valve for feeding pressure oil to the piston head side room of the second cylinder 5 is kept closed, and accordingly the second cylinder 5 is not operated to be elongated. When the first cylinder 4 is elongated to its limit, the check valve 15 is forcibly opened by the action of a first forcing member (hollow rod 12), pressure oil is supplied to the second cylinder 5 to be operated to be elongated, and in this way, the cylinders are sequentially elongated.</p> |
