Camshaft adjusting device

US7513230B2 · kind B2 · utility

Assignee

• Hydraulik-Ring GmbH · DE

Inventors

• Andreas Knecht · Herrenberg, DE
• Helmut Patze · Frammersbach, DE
• Udo Diederichs · Ratingen, DE
• Udo Schwandt · Dietenheim, DE

Key dates

• Filing date: Jun 27, 2005
• Grant date: Apr 7, 2009
• Expiry date: Feb 4, 2026

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F01L2820/01
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A camshaft adjusting system for an internal combustion engine has a camshaft adjusting device with a first hydraulic chamber and a second hydraulic chamber, wherein the first and second hydraulic chambers act in opposition to one another. A control valve group working as a 4/4-way valve system has a first connection to the first hydraulic chamber, a second connection to the second hydraulic chamber, a tank connection, and a connection for pressurization. The camshaft adjusting system in a first state of the control valve group, when starting the internal combustion engine, is pressure-relieved relative to the tank connection by simultaneously hydraulically connecting the first and second connections of the camshaft adjusting device so that the camshaft adjusting device moves into a dwell position with a single locking mechanism. The dwell position also provides a safety function in case of system failure.