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US 10,947,924 B2Granted
Engine exhaust valve shield
AssigneeFord Global Technologies, LLC
InventorsIan Cattermole, Paul Thomas Reinhart
Life of this patent
Estimating the term…
Abstract
An internal combustion engine has a cylinder head defining an exhaust valve guide bore with a side wall and an end wall, and an exhaust valve stem passage extending between an exhaust port and the end wall of the bore. A diameter of the passage is less than a diameter of the bore. An exhaust gas valve guide is positioned in the bore and spaced apart from the end wall to form an air gap therebetween.
Claims14
An engine comprising:
- a cylinder head defining an exhaust valve guide bore having a continuous, cylindrical side wall intersecting a wall of an exhaust port;
- a cylindrical washer having an outer diameter sized to be press fit with the side wall of the bore such that an outer face of the washer is flush with the wall of the exhaust port adjacent thereto, the washer defining an exhaust valve stem passage having a diameter less than a diameter of the bore;
- and
- an exhaust gas valve guide spaced apart from an inner face of the washer to form an air gap therebetween and having a cylindrical outer wall circumferentially contacting the side wall;
- wherein a coating is provided on at least one of the inner and outer faces of the washer, the coating configured to control a temperature of the guide during engine operation;
- and
- wherein a length of the air gap between the guide and the washer is sized to control a temperature of the guide during engine operation to reduce heat transferred to the guide while preventing overcooling and provide thermal expansion of the guide to reduce wear.
4 more elements
A cylinder head comprising:
- a washer configured as an exhaust gas valve guide shield, the washer extending between an exhaust port and a bore sized to receive a valve guide, the washer having an outer diameter sized for a press fit with a continuous side wall of the bore and extending radially inwards to form a valve stem passage, a first side of the washer positioned to be flush with an adjacent wall of the exhaust port, a second side of the washer forming an end wall of the bore;
- and
- an exhaust gas valve guide positioned in the bore and having a cylindrical outer wall extending to an end of the guide, the cylindrical outer wall circumferentially contacting the side wall of the bore, the end of the guide spaced apart from the second side of the washer to form an air gap defined by the end of the guide, the second side of the washer, and the side wall of the bore.
Dependencies are inferred from the claim text.