Crank-case ventilation filter set equipped with check valve

Abstract

A crank-case ventilation filter set. A crankcase ventilation filter filters oil from blow-by gas. An inlet pipe transports the blow-by gas from an engine to the filter. An outlet pipe transports the blow-by gas from the filter to an intake device. An oil return pipe transports oil, such as by gravity, from the filter to an oil pan provided at a lower portion of the engine. A valve for preventing back-flow of oil is provided in the oil return pipe. The valve is disposed in the oil pan above an oil top limit line of the oil pan.

1 . A crank-case ventilation filter set, comprising:
 a crankcase ventilation filter for filtering oil from blow-by gas;   an inlet pipe configured to transport the blow-by gas from an engine to the filter;   an outlet pipe configured to transport the blow-by gas from the filter to an intake device;   an oil pan provided at a lower portion of the engine;   an oil return pipe configured to transport oil from the filter to the oil pan; and   a valve for preventing back-flow of oil, provided on the end of the oil return pipe, and disposed in the oil pan above an oil top limit line of the oil pan, wherein the valve includes:
 an end wall closing the end of the oil return pipe, the end wall having a hole 
 a covering that covers the hole of the oil return pipe; and 
 a projection extending from the covering and through the hole of the oil return pipe, wherein an end portion of the projection is wider than the hole. 
   
   
   
       2 . The crank-case ventilation filter set of  claim 1 , wherein the oil return pipe is configured to transport the oil by gravity.