Investigation on the development and the controllability of a compact multi-functional, fully variable-valve-actuation system

Abstract

A compact multi-functional, fully variable valve actuation system for six-cylinder engines was proposed. The system can run in both the drive mode and the brake mode of internal-combustion engines. With the help of a distributor, fully variable valve events were achieved with two oil-supply sets, two solenoid valves and one drain valve. The operational parameters of the valve can be adjusted independently for individual cylinders. A numerical study on the controllability of the system was carried out with AVL Hydsim. The calculation results revealed that the timing of the valve opening, the maximum lift, the duration and the time-area value can be adjusted independently or synchronously by controlling the solenoid valves and/or the drain valve. Further correlation analysis results revealed that all the operational parameters of the valve had approximately linear relationships with the corresponding control parameters, and all the correlation coefficients were larger than 0.95, indicating good controllability of the system.

A comparative assessment of performance, combustion, and emissions of a gasoline port and direct injection camless engine

“…16 Electro-hydraulic, electromagnetic, and electro-pneumatic camless VVA systems are currently in the early stage of development. [17][18][19] In the electro-hydraulic VVA system, [20][21][22][23][24][25] the high-pressure liquid in the hydraulic actuator actuates the valve in both forward and backward directions. The valve events are controlled by energizing and de-energizing the hydraulic solenoids, which control the actuator piston motion.…”

Design and Dynamic Analysis of an Innovative Axial Shift Valvetrain System (ASVS) for Variable Stroke Engine

“…The existing variable valve actuation systems are classified into two groups: cam-driven and camless systems. 12 The cam-driven system has been widely adopted in four-stroke gasoline engines as it has simple structure, reliable operation, and quick response, while the camless systems are yet to be implemented in production for commercial issues. 13 The conventional variable valve timing system (VVT), such as VVT-i phaser of Toyota, 14 VANOS of BMW, 15 and VLD systems, 16,17 are hardly applied on a VSE.…”