| 摘要 |
<p>PURPOSE:To provide an oil pressure intensifying circuit capable of supplying both low pressure and high pressure in response to the magnitude of load to an operating cylinder in the forward stoke of the operating cylinder without causing the fluctuation in oil pressure due to the cycle operation of a pressure intensifying unit on the side where a load is applied. CONSTITUTION:An oil pressure intensifying circuit consists of two priority valves 1 and 2, a change-over valve 4, a pressure intensifying unit consisting of a pressure intensifying spool 5 and pressure intensifying pistons 6, four check valves, and a pilot check valve 3, and is capable of supplying in the forward stroke of the operating cylinder low oil pressure through a low pressure circuit to an operating cylinder when a light load is applied, and of supplying high oil pressure through a high pressure circuit when a heavy load is applied. In this case, a pressure intensifying chamber and a pressure pipe A' attached to a pressure intensifying piston, are connected to each other through a check valve 7 which is opened and closed in response to the increase or the decrease in oil pressure in the presser intensifying chamber. The forward stroke of the operating cylinder is adapted to return the return oil from the operating cylinder to an oil tank through the second priority valve 2 and/or the first priority valve 1.</p> |
