Cam for controlling valves of an internal combustion engine

US3981281A · kind A · utility

Assignee

• Maschinenfabrik Augsburg-Nurnberg · DE

Inventors

• Gerhard Deschler · Nuremberg, DE
• Dieter Wittmann · Leverkusen, DE
• Reinhold Trier

Key dates

• Filing date: Jun 20, 1975
• Grant date: Sep 21, 1976
• Expiry date: Jun 20, 1995

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T74/2101
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A cam for controlling the valve of an internal combustion engine which controls the valve by means of a valve tappet having a flat bottom, against the thrust of a closing spring. The acceleration and the deceleration regions are divided into a total of five sections I-V of which the acceleration sections I and V are defined by a Fourier series of the third order represented by the equation: EQU z.sub.J.sub." = a.sub.j.spsb.1.sup.. sin .alpha. + a.sub.j.spsb.2.sup.. sin 2.alpha.+a.sub.j.spsb.3.sup.. sin 3.alpha. in which j represents one of the respective sections I and V, while a.sub.j.spsb.1 to a.sub.j.spsb.3 are selected in conformity with the required conditions, and while .alpha. represents a function of the cam angle x. The section II which follows the opening flank and the section IV preceding the closing flank result in a precisely constant ascent of the lubrication number curve while in connection with the cam stroke to section II the following equation applies: EQU z.sub.II = a.sup.. sin[.sqroot. 0.5( x-WPO)]-SK(x-WPO)+z.sub.A II and while section IV is represented by the equation: EQU z.sub.IV =a.sub.7.sup.. sin [.sqroot. 0.5( x-SKS)]+a.sub.8.sup.. cos[.sqroot. 0.5(x- SKS…