| 摘要 |
<p>An agricultural implement carried/driven by a tractor, for the dosed supply of liquid fertilizer to distinct fertilizing areas (12) is explained. The implement comprises at least a double-acting hydraulic piston and cylinder (1) with a piston (4), without a piston rod, displaceable by the higher fluid pressure of one cylinder chamber (2, 3) or the other. Fertilizer liquid is used in both cylinder chambers, and one cylinder chamber (3) which is in valve-conditional fluid communication with a fertilizer liquid supply pipe (11), whose discharge end may be above or below the soil surface at the fertilizing area (12), works alternately as an ejecting chamber for liquid fertilizer and a hydraulic cylinder chamber. Thereby is prevented, on the one hand, that liquid fertilizer which is ejected, contains hydraulic oil, and, on the other hand, that corrosive fertilizing liquid enters the hydraulic system of the tractor and causes damage.</p> |
