Solenoid valve for recycling exhaust gases in internal combustion engines

Claim 1

A solenoid valve for controlling the recycling of exhaust gases from the exhaust pipe into the intake manifold of an internal combustion engine comprising, in combination: a. a valve housing having inlet and outlet means to permit passage of said exhaust gases through said housing in an open valve position; b. an electromagnet functioning as a valve setting member; c. a movable valve rod of given outer diameter extending to said electromagnet; d. a first valve seat defining an opening establishing communication between said inlet and outlet means through said housing; e. a second valve seat defining an opening through which said valve rod extends to said electromagnet; f. a movable valve head situated in said housing and secured to said valve rod, said valve head being movable into a first position in which it is seated in said first valve seat for blocking the passage of exhaust gases through said housing, said valve head being movable into a second position in which it is spaced from said first valve seat for permitting the passage of exhaust gases through said housing, said valve head being seated in said second valve seat in said second position to prevent exhaust gases from passing to said electromagnet; and g. a thin-walled, sleeve-shaped spacer tube having an inner diameter which is a multiple of at least two of said given diameter for accommodating, without obstructing motion of said valve rod, dirt particles carried by exhaust gases, said thinwalled sleeve being made of a material of low heat conductivity for preventing heat transmission from hot exhaust gases and said housing to said electromagnet, said spacer tube having one end affixed to said housing and another end affixed to said electromagnet, said spacer tube holding said electromagnet spaced from and externally of said housing, said valve rod passing longitudinally through said spacer tube and said thinwalled sleeve member being relatively thin with respect to its said inner diameter.