초록 ▼

In a load holding valve L, comprising a check valve R and a pressure limiting valve D in a housing chamber which is common to said two valves, a seat insert 13 has provided therein a valve seat 19 for a closure member 4 of the pressure-limiting valve D and a sealing surface 15 for a check-valve clos

In a load holding valve L, comprising a check valve R and a pressure limiting valve D in a housing chamber which is common to said two valves, a seat insert 13 has provided therein a valve seat 19 for a closure member 4 of the pressure-limiting valve D and a sealing surface 15 for a check-valve closure member 16, and an opening piston 9, which is coupled to the closure member 4, is provided in a pilot chamber 10, an effective area of said closure member 4 being, in a direction opposite to the direction of spring loading, adapted to be acted upon by the pressure to be limited, the opening piston 9 is formed integrally with the closure member 4 and is provided with a pressure surface in the pilot chamber 10 which is slightly smaller than the cross-sectional area of the valve seat 19, and the valve seat 19 defines in combination with control passages K formed in the closure member 4 a stroke-dependent quantity control device M.

대표청구항 ▼

[ I claim:] [1.] A load holding valve (L) for high-pressure hydraulic systems, comprising a check valve (R) permitting flow in one direction of flow and a pressure limiting valve (D) which is arranged in said check valve (R) and which controls a flow in the opposite direction of flow in a pressure-d

[ I claim:] [1.] A load holding valve (L) for high-pressure hydraulic systems, comprising a check valve (R) permitting flow in one direction of flow and a pressure limiting valve (D) which is arranged in said check valve (R) and which controls a flow in the opposite direction of flow in a pressure-dependent manner, further comprising a stationary seat insert (13) in a housing chamber (12) which said valves (R, D) have in common, said seat insert (13) comprising as structurally separate components a valve seat (19) for a spring-loaded closure member (4) of the pressure limiting valve (D) and a sealing surface (15) for a check-valve closure member (16), and further comprising a coaxial opening piston (9) which is coupled to the closure member (4) of the pressure limiting valve (D) and which is arranged in the pilot chamber (10), said closure member (4) of the pressure limiting valve (D) being provided with an effective area which, in a direction opposite to the direction of spring loading, is adapted to be acted upon by a pressure to be limited, characterized in that the opening piston (9) is formed integrally with the closure member (4) of the pressure limiting valve (D) and has in the pilot chamber (10) a pressure surface which is effective in the opening direction of the pressure limiting valve (D) and which is slightly smaller than the cross-sectional area of the valve seat (19), and that the valve seat (19) in combination with control passages (K) formed in the closure member (4) of the pressure limiting valve (D) define a stroke-dependent quantity control device (M) for the opposite direction of flow.