摘要 |
<p>The invention relates to Hydraulic valve device comprising a first engine port (L) and a second engine port (N) to a double acting hydraulic motor (D), in particular a double acting hydraulic cylinder, a tank (T), and a pump (I), a hand valve (H), which is arranged such that it connects the engine ports (L, N) to the tank (T) and the pump (I), and which hand valve (H) has two open positions, wherein the pump (I) in the first open position via a line (F) is connected to the first engine port (L) and the tank (T) via a line (G) is connected to the second engine port (N), and wherein the pump (I) in the second open position via the line (G) is connected to the second engine port (N) and the tank (T) via the line (F) is connected to the first engine port (L), and a first nonreturn valve (IA, 8), which is arranged between the pump (I) and the second engine port (N) and opens towards the second engine port (N). Further, a piston (2), which by means of the load pressure in the first engine port (L) via a line (E) governs the first nonreturn valve (IA, 8), such that it is kept closed as long as the pump pressure does not exceed said load pres¬ sure, and a second nonreturn valve (3), which is arranged such that it, as long as the hand valve (H) is in its first open position, connects the first engine port (L) to the second engine port (N) and opens in direction towards the second engine port (N).</p> |