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:
Mar. 11, 2008
Filed:
Nov. 27, 2003
Wolfgang Issler, Schwaikheim, DE;
Wolfgang Issler, Schwaikheim, DE;
MAHLE GmbH, Stuttgart, DE;
Abstract
The invention relates to a method for coating piston rings () for internal combustion engines, wherein at least the bearing surface of the piston ring is provided with an anti-abrasion and anti-corrosion coating () by means of a PVD or electroplating process. According to said method, the anti-abrasion and anti-corrosion coating is prevented from flaking or cracking caused by strain occurring on the piston ring during the operation of the motor by means of the following steps: a) coating parameters are set; b) an uncoated piston ring () is pre-stressed in order to obtain a predetermined diameter () thereof or opening width (); an ion coating process is carried out using coating parameters according to step a); the internal stress of the anti-abrasion or anti-corrosion coating () is measured in state (b); e) a new, uncoated piston ring () is subjected to tensile pre-stressing or compressive strain according to the measured internal tension of the coating; and f) the piston ring is coated () according to the coating parameters according to step a).