The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 25, 2000
Filed:
Dec. 22, 1997
Martin Mutterer, Leutenbach, DE;
Eckhart Nitzschke, Stuttgart, DE;
Tilmann Roemheld, Weinstadt, DE;
Willy Treyz, Neckartailfingen, DE;
DaimlerChrysler AG, Stuttgart, DE;
Abstract
A cast cylinder head for an internal-combustion engine, in which the charge cycle ducts have a fluctuating duct offset relative to the valve opening caused by the casting technique. Proximate the opening, the charge cycle ducts are provided with a machining allowance which increases toward the duct end and are machined there in a cutting manner so that the interior surface of the charge cycle ducts changes in each case without an offset into the valve opening. In order to achieve a simple tool guiding and nevertheless a machining which is advantageous to the flow, a compensating groove is arranged in the machining allowance of the charge cycle ducts which has a flat V-shaped cross-section and extends in the circumferential direction, specifically--relative to the flow direction--at least in the area of a convex course of the duct wall. The groove flanks have a convex cross-section and are curved to be as free of flow separations as possible. The compensating groove extends at a distance above the upper edge of the valve seat ring which corresponds to approximately 20 to 30% of the inside diameter of the valve opening. The groove base is situated outside the ideal course of the duct surface. The compensating groove extends at least approximately in a plane which is situated approximately at a right angle relative to the duct center line. The depth of the groove measured to the duct tangent corresponds approximately to the maximal core offset.