Valvetronic

Valvetronic (proper spelling: VALVETRONIC ) is a fully variable valve control of gasoline engines of the automobile manufacturer BMW. It was first four-cylinder engine in the 316i Compact employed in the available starting in 2001 1,8 l (85 kW).

With Valvetronic the intake quantity is not regulated as usual via a rotatably mounted throttle valve in the gas stream, but a variable lift of the intake valve, which is controlled within 300 ms between 0.25 mm and 9.8 mm. A servomotor VDO with an eccentric shaft moves the lever stroke, the rocker arm and thus the valve lift. Thus, the intake valves take over the function of the throttle valve. Although this is still available, but is used only in special operating conditions, such as in emergency operation.

In addition to the valve control an adjustment of the valve timing ( opening angle ) is used by camshaft adjustment in the equipped with Valvetronic engines, called by BMW VANOS.

Effects

Due to the throttle-free load control charge exchange losses are drastically reduced, also the higher inflow leads to a better mixing of the fuel -air mixture in the cylinder. Thereby, the fuel consumption by about 10% (BMW specification ) is less than in conventional engines.

Swell

• Patent DE4223172: cylinder head supported with on an eccentric shaft rockers. Remember on July 15, 1992 published on 19 August 1993 Applicant: Bayerische Motoren Werke Aktiengesellschaft, 80809 Munich, Inventor: Harald Unger.
• Harald Unger: VALVETRONIC. The contribution from the valvetrain to reduce the CO2 emissions of the gasoline engine ( = The Library of Technology. 263 ). verlag moderne industrie, Landsberg am Lech 2004, ISBN 978-3-478-93308-7.
• Karl -Heinz Dietsche, Thomas Hunter, Robert Bosch GmbH: Automotive Handbook. 25th Edition, Friedr. Vieweg & Sohn Verlag, Wiesbaden, 2003, ISBN 3-528-23876-3