Crankcase ventilation system

Claim 2

A crankcase ventilation system for an automotive gasolinepowered engine having an intake manifold and an air cleaner for cleaning the air delivered to said intake manifold, which system comprises a crankcase, a ventilation air inlet provided in said crankcase and opened to the atmosphere, a ventilation air check valve mounted in said ventilation air inlet, a blowby gas mixture outlet provided in said crankcase, a blowby gas mixture conduit connecting said outlet with said air cleaner, a blowby gas mixture check valve mounted in said blowby mixture conduit, a branch conduit branched from said blowby gas mixture conduit before said blowby mixture gas check valve and communicating with said intake manifold of the engine, and means defining an orifice provided in said branch conduit, whereby as the pressure in the crankcase is increased due to the presence of blowby gases therein, said ventilation air check valve closes to stop delivery of atmospheric air into the crankcase and concurrently said blowby gas mixture check valve opens to release the mixture of the blowby gas and air into the engine air cleaner.

Claim 3

The system as set forth in claim 1, further comprising an air cleaner element located upstream of said ventilation air check valve.

Claim 4

The system as set forth in claim 1, wherein at least one of said check valves comprises, in combination, a valve seat having provided therein a plurality of openings, a valve plate made of a pliable material and superposed on said valve seat for normally closing said openings, a shallow cuplike retainer superposed on said valve plate and a rivet means fastening said valve seat, valve plate and retainer in place, said valve plate becoming warped, in situ, against said retainer with a force exercised thereto through said openings whereby said check valve is held in an open position.

Claim 5

The system as set forth in claim 1, wherein at least one of said check valves comprises, in combination, a generally cylindrical casing which is opened at one end and closed at the other with a wall having provided therein a plurality of openings, an annular valve seat mounted at the entire periphery of said open end of the casing, a ball member normally resting on said valve seat, a coil spring acting to normally hold said ball member against said valve seat, and a generally cuplike retainer mounted between said ball member and said coil spring, wherein said ball member is forced away from said valve seat against the action of said coil spring with a force exercised on said ball member through said open end of said casing.

Claim 6

The system as set forth in claim 1, wherein said orifice is constituted as a unitary tubular member having its downstream end sharpened and constricted internally and radially.

Claim 7

The system as set forth in claim 1, wherein said orifice comprises a tubular member and a ball member accommodated therEin, said tubular member having portions internally and radially raised at its upstream and downstream ends.

Claim 8

A crankcase ventilation system for an automotive gasoline-powered engine, which system comprises a ventilation air inlet provided in the wall of the crankcase and opened to the atmosphere through a ventilation air conduit, a ventilation air check valve mounted in said ventilation air conduit, a blowby gas mixture outlet provided in the wall of the crankcase past the oil separator thereof, a blowby gas mixture conduit connecting said outlet with the engine air cleaner, a blowby gas mixture check valve mounted in said blowby mixture conduit, a branch conduit branched from said blowby gas mixture conduit before said blowby mixture gas check valve and communicating with the intake manifold of the engine, and an orifice provided in said branch conduit, wherein, as the pressure in the crankcase is increased due to the presence of blowby gases therein, said ventilation air check valve closes to stop delivery of atmospheric air into the crankcase and concurrently said blowby gas mixture check valve opens to release the mixture of the blowby gas and air into the engine air cleaner.

Claim 9

A crankcase ventilation system for an automotive gasoline-powered engine, which system comprises a ventilation air inlet provided in the wall of the crankcase and opened to the atmosphere through a ventilation air conduit, a ventilation air check valve mounted in said ventilation air conduit, a blowby gas mixture outlet provided in the wall of the crankcase past the oil separator thereof, a blowby gas mixture conduit connecting said outlet with the engine air cleaner, a blowby gas mixture check valve mounted in said blowby mixture conduit, a branch conduit branched from said blowby gas mixture conduit before said blowby mixture gas check valve and communicating with the intake manifold of the engine, and an orifice provided in said branch conduit, wherein, as the pressure in the crankcase is increased due to the presence of blowby gases therein, said ventilation air check valve closes to stop delivery of atmospheric air into the crankcase and concurrently said blowby gas mixture check valve opens to release the mixture of the blowby gas and air into the engine air cleaner.

Claim 10

The system as set forth in claim 7, wherein said ventilation air conduit communicates with the engine air cleaner.

Claim 11

The system as set forth in claim 7, wherein at least one of said check valves comprises, in combination, a valve seat having provided therein a plurality of openings, a valve plate made of a pliable material and superposed on said valve seat for normally closing said openings, a shallow cuplike retainer superposed on said valve plate and a rivet means fastening said valve seat, valve plate and retainer in place, said valve plate becoming warped, in situ, against said retainer with a force exercised thereto through said openings whereby said check valve is held in an open position.

Claim 12

The system as set forth in claim 7, wherein at least one of said check valves comprises, in combination, a generally cylindrical casing which is opened at one end and closed at the other with a wall having provided therein a plurality of openings, an annular valve seat mounted at the entire periphery of said open end of the casing, a ball member normally resting on said valve seat, a coil spring acting to normally hold said ball member against said valve seat, and a generally cuplike retainer mounted between said ball member and said coil spring, wherein said ball member is forced away from said valve seat against the action of said coil spring with a force exercised on said ball member through said open end of said casing.

Claim 13

The system as set forth in claim 7, wherein said orifice is constituted as a unitary tubular member having its downstream end sharpened and constricted internally and radially.

Claim 14

The system as set forth in claim 7, wherein said orifice comprises a tubular member and a ball member accommodated therein, said tubular member having portions internally and radially raised at its upstream and downstream ends.

Claim 15

In combination with an internal combustion engine having an intake manifold and having a crankcase chamber receptive of engine blowby mixtures and being maintained under fluctuating positive and negative fluid pressure conditions during engine operation, a carburetor connected to said intake manifold having a throttle valve operable to regulate the supply of air-fuel mixtures delivered through said intake manifold to said engine, an improved crankcase ventilation system for scavenging the crankcase chamber and recycling the engine blowby mixtures comprising: first valve means for admitting atmospheric air into said crankcase chamber to effectively scavenge same in response to negative fluid pressure conditions therein; means including second valve means for communicating said crankcase chamber with said carburetor upstream of said throttle valve only when the fluid pressure within said crankcase chamber is greater than the fluid pressUre upstream of said throttle valve to allow flow of crankcase chamber fluids including engine blowby mixtures to said carburetor; and flow control means for continuously controlling the flow of crankcase chamber fluids to said intake manifold downstream from said throttle valve.

Claim 16

In combination with an internal combustion engine having an intake manifold and having a crankcase chamber receptive of engine blowby mixtures and being maintained under fluctuating positive and negative fluid pressure conditions during engine operation, a carburetor connected to said intake manifold having a throttle valve operable to regulate the supply of air-fuel mixtures delivered through said intake manifold to said engine, an improved crankcase ventilation system for scavenging the crankcase chamber and recycling the engine blowby mixtures comprising: first valve means for admitting atmospheric air into said crankcase chamber to effectively scavenge same in response to negative fluid pressure conditions therein; means including second valve means for communicating said crankcase chamber with said carburetor upstream of said throttle valve only when the fluid pressure within said crankcase chamber is greater than the fluid pressUre upstream of said throttle valve to allow flow of crankcase chamber fluids including engine blowby mixtures to said carburetor; and flow control means for continuously controlling the flow of crankcase chamber fluids to said intake manifold downstream from said throttle valve.

Claim 17

A combination according to claim 13; wherein said flow control means comprises a conduit providing fluid communication between said crankcase chamber and said intake manifold, and means defining a metering orifice disposed within said conduit to meter the flow of crankcase chamber fluids in accordance with fluid pressure differentials thereacross.

Claim 18

A combination according to claim 14; including a knife edge peripherally surrounding said metering orifice to prevent formation thereupon of sludge deposits.

Claim 19

A combination according to claim 13; wherein said first valve means comprises means defining an opening communicating said crankcase chamber with the atmosphere, and a check valve operable to open and close said opening in direct response to fluid pressure differentials applied thereacross; and wherein said means including second valve means for communicating said crankcase chamber with said carburetor upstream of said throttle valve comprises means defining another opening in said crankcase chamber, means defining a passageway communicating said another opening with said carburetor upstream of said throttle valve, and another check valve operable in direct response to fluid pressure differentials applied thereacross to open and close said another opening.

Claim 20

A combination according to claim 16; wherein said flow control means comprises a conduit connected to said passageway and said intake manifold, and means defining a metering orifice disposed within said conduit effective to meter the flow of crankcase chamber fluids to said intake manifold in response to fluid pressure differentials thereacross.

Claim 21

A combination according to claim 13; including an air filter in communication with the atmosphere disposed upstream from said carburetor; and a conduit providing fluid communication between said first valve means and said air filter; whereby atmospheric air admitted into said crankcase chamber first passes through said air filter.