Apparatus for adjusting valve timing of gas exchange valves in an internal combustion engine

US5927239A · kind A · utility

Assignee

• INA Wälzlager Schaeffler oHG · DE

Inventors

• Mike Kohrs · Wilthen, DE
• Andreas Strauss · Forchheim, DE
• Jochen Auchter · Weisendorf, DE

Key dates

• Filing date: May 28, 1998
• Grant date: Jul 27, 1999
• Expiry date: May 28, 2018

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F01L1/34406
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

Apparatus for adjusting the valve timing of gas exchange valves in an internal combustion engine, includes a driving unit in driving relationship with a crankshaft, a driven unit fixedly secured to an intake camshaft or exhaust camshaft, and an adjusting member operatively connected to the driving unit and the driven unit and capable of reciprocating between two axially spaced end positions by a hydraulic medium. In order to prevent noise emission after ignition of the engine, a coupling member is provided to interact with the driving unit and to move between an idle position in which the coupling member is disengaged from the driving unit and an operative position in which the coupling member interlocks with the driving unit and effects a fixed rotative engagement between the driving unit and the driven unit to lock the adjusting member in place when pressure applied by hydraulic medium drops below a level required for displacing the adjusting member. The apparatus further includes a flow restrictor so positioned as to effect a cross sectional constriction in a flow passageway upstream of the coupling member to attenuate pressure pulsation generated by the hydraulic medium.