A Study of a Continuous Variable Valve Event and Lift (VEL) System NISSAN MOTOR CO., LTD

Format:

Book

Conference/Event

Author/Creator:

Takemura, Shinichi, author.

Conference Name:

SAE 2001 World Congress (2001-03-05 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2001

Summary:

A new variable valve actuation system that varies valve lift and timing events continuously has been devised and confirmed to substantially improve power and reduce fuel consumption when applied to a SI engine. The variable valve event and lift (VEL) system is a simple mechanism consisting of oscillating cams and linkages, enabling it to operate the valves smoothly even at high speed. Its compact size facilitates application to direct-acting valve trains and its ability to vary valve lift from a deactivated state (0) to a large lift amount allows the system to be used with a wide range of engine concepts.In this study, VEL was combined with a phase shifting function to enable the valve lift characteristic to be varied virtually arbitrarily, and test results showed that fuel consumption of a SI engine was reduced by nearly 10%. This effect is attributed to lower friction loss due to the use of extremely small valve lift-timing events and reduction of pumping loss resulting from effective use of internal exhaust gas recirculation.The VEL system substantially improves combustion because the extremely small valve lift-timing events increase the intake air flow rate, which is also expected to be effective in reducing cold-start HC emissions. These results indicate that the VEL system has the potential to achieve a SI engine that provides both low fuel consumption and low emissions.This paper describes the newly developed VEL mechanism and its effect on the performance of a V6 test engine fitted with the system

Notes:

Vendor supplied data

Publisher Number:

2001-01-0243

Access Restriction:

Restricted for use by site license