Shrouded valve for internal combustion engine

#The present invention relates to intake valves for internal combustion engines and more particularly to a shroud for the intake valve that initiates controlled turbulence of the combustion charge during the intake stroke.

#The advantages of providing intense turbulence during selected combustion phases of a spark ignition engine have long been recognized as a means of increasing the rate of combustion or flame propagation.

#In a spark ignition engine, both turbulence and swirl are created at the intake stroke. As a result, the intake stroke is one key to controlling the combustion process inside the combustion chamber of the engine. Prior art attempts to increase turbulence in internal combustion engines include using different inlet port designs, separating the various combustion phases and the use of deflector plates, as illustrated for example in U.S. Pat. No. 3,757,757 to Bastenhof, and in the case of Diesel engines, the use of deflector plates on the inlet valves, the effect of which has been to increase the swirling motion and incidentally, the turbulence intensity of the oil spray charge, when introduced directly into the cylinder burning chamber.

#The various features, objects and benefits of the present invention will be more completely appreciated upon reading the detailed description of the invention in connection with the drawings. In the drawings,

#FIG. 1 is a fragmentary cross-sectional view of a portion of one cylinder of an engine illustrating in elevation an intake valve in its raised or closed position including a preferred embodiment of a valve shroud;

#FIG. 2 is a view similar to FIG. 1 showing the intake valve of FIG. 1 in an open position, with a portion of the valve shroud broken away to show details thereof;

#Referring to FIG. 1, part of a spark ignition internal combustion engine is illustrated and includes an engine block 10 formed with a cylinder bore 12 slidably receiving a conventional reciprocating piston 14 having an upper surface 16. A cylinder head 18 is located above the block 10 and closes the bore. Thus, the block, together with upper surface of the piston, defines a combustion chamber 20.

#An intake poppet valve, generally indicated at 22, is provided for the combustion chamber 20 and includes a valve stem portion 24 disposed in conventional valve guide means (not shown) for reciprocal movement in a passage 26 within the block 10. The valve head portion 28, including a valve margin 30, is interconnected by a frusto-conical face portion 32, often referred to as the valve neck, to the valve stem 24. Spark ignition means in the form of conventional spark plug (not shown) is provided for igniting the combustible charge in chamber 20 upon the charge entering the chamber from induction passage 26.

#According to the principles of the present invention the valve 22 includes a shroud 34 in the form of a circular or 360.degree. collar having a centrally located hollow bore 36 defining a lower annular shroud edge 38 and an upper annular shroud edge 40.