| 摘要 |
<p>PURPOSE:To prevent generation of surging pressure in a discharge pipe by furnishing a sensor at a drive cylinder for concrete pump etc. to sense such motions of piston as advance, retraction and reversal, and by controlling supply of the working oil to the drive cylinder in accordance with the signal given from said sensor. CONSTITUTION:Oil-hydraulic cylinders 3a, 3b for driving installed behind pump cylinders 2a, 2b are equipped with sensors 46a, 46b to sense retraction of piston, sensors 47a, 47b to sense the advance, and sensors 48a, 48b to sense reversal from retraction to advance. Signal from No.1 retraction sensor stops inflow of the working oil into the corresponding drive cylinder, and signal from the No.2 advance sensor allows inflow of the working oil into said No.1 drive cylinder for the purpose of reversal. Signal from reversal sensor allows inflow of the working oil into No.2 cylinder for the purpose of retracting the piston.</p> |
