Crankcase ventilation valve for internal combustion engines

Claim 1

Crankcase ventilation valve for internal combustion engines with a valve casing which is divided into a first and a second chamber by a displaceable wall sealingly attached at the periphery, wherein the first chamber is in communication with the atmosphere and the second chamber is in communication on the one hand through an inlet tube with the crankcase and on the other hand through an outlet tube with the suction device by way of a cylindrical tubular member disposed in the second chamber, the displaceable wall and the tubular member being constructed as a non-return valve and the valve seat being surrounded by a concentric ring space which is connected to the inlet tube, wherein the displaceable wall is constructed as a diaphragm of a very light, elastic material; a support surface for the diaphragm is arranged around the tubular member forming the valve seat face, above the concentric ring space, the diaphragm extending to the edge of the valve casing; the support surface comprises an annular groove at the outer edge and radially extending support ribs which are arranged at a spacing and which extend from the concentric ring space, and wherein the diaphragm is arranged in the annular groove for providing tension and in its closing position rests on the support ribs and the ratio of the surface of the diaphragm loaded by the pressure of the suction device to that loaded by the pressure of the crankcase amounts to at least 1:10.