Study on Valve Strategy of Variable Cylinder Deactivation Based on Electromagnetic Intake Valve Train

Abstract

The camless electromagnetic valve train (EMVT), as a fully flexible variable valve train, has enormous potential for improving engine performances. In this paper, a new valve strategy based on the electromagnetic intake valve train (EMIV) is proposed to achieve variable cylinder deactivation (VCD) on a four-cylinder gasoline engine. The 1D engine model was constructed in GT-Power according to test data. In order to analyze the VCD operation with the proposed valve strategy, the 1D model was validated using a 3D code. The effects of the proposed valve strategy were investigated from the perspective of energy loss of the transition period, the mass fraction of oxygen in the exhaust pipe, and the minimum in-cylinder pressure of the active cycle. On the premise of avoiding high exhaust oxygen and oil suction, the intake valve timing can be determined with the variation features of energy losses. It was found that at 1200 and 1600 rpm, fuel economy was improved by 12.5–16.6% and 9.7–14.6%, respectively, under VCD in conjunction with the early intake valve closing (EIVC) strategy when the brake mean effective pressure (BMEP) ranged from 0.3 MPa to 0.2 MPa.

Simulation and Analysis of the Impact of Cylinder Deactivation on Fuel Saving and Emissions of a Medium-Speed High-Power Diesel Engine

“…The principle of CDA application for reduced fuel consumption in spark ignition (SI) engines is that after some cylinders are deactivated, the rest of the active cylinders require more fresh charge to maintain the brake mean effective pressure (BMEP); as a result, the throttle valve opens more widely, intake manifold pressure increases, and pumping losses decrease [11]. The application of CDA with variable valve actuation (VVA) in SI engines contributes to reducing the brake-specific fuel consumption (BSFC) up to 17-25% depending on engine configuration, operating points, and engine control [12][13][14][15]. CDA operation combined with dynamic skip fire strategies can reduce engine vibration and bring an additional reduction in BSFC [16,17].…”

A Novel Design Concept of Electromagnetic Valve Actuator with High Starting Force

“…This challenge in independent ICE valve electromagnetic control is being approached by developing an electromagnetic valve actuator design with an appropriate force-stroke characteristic, which would enable a high level of flexibility in valve timing control and lifting [2,5]. However, so far finding an appropriate solution for successful electromagnetic valve timing control has been a demanding task due to the pronounced nonlinearity of the force stroke characteristic and high landing velocity [2,4,11,12,[16][17][18][19][20].…”