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This paper proposes a new electromagnetic valve train (EMV), which uses hybrid permanent magnet and electromagnetic coil (PM/EM). The new EMV is characterized by a special structure, simple actuator as well as optimal parameter designs. This EMV brings many benefits, such as valve dynamic, actuator control, and low operation energy consumption, etc. The simulation results show that this EMV achieves a 15% volume reduction and a 20% enhancement in holding force by special armature design. Additionally, the estimated energy consumption of EMV operation for the proposed EMV indicates that this EMV has the lowest operating energy compared with other EMVs.

Valve timings of a spark ignition engine have been limited to a narrow range of alternatives within the constraints of the fuel economy, the emissions and the dynamic performance. Variable valve timing shows promise as a new key technology for improving the fuel consumption and emissions of spark ignition engines. Several techniques have been developed to perform variable valve timing, and the method with the most potential, called a hybrid electromagnetic valvetrain actuator, is an electromagnetic valvetrain with a permanent magnet and electromagnetic coils installed together. In this study, a novel hybrid electromagnetic valvetrain with a permanent magnet and electromagnetic coils, which significantly differs from existing electromagnetic valvetrains, was designed to overcome the drawbacks of conventional electromagnetic valvetrains that have been introduced previously. This new hybrid electromagnetic valvetrain is characterized by a simple structure, simple actuation and an ultra-low actuating power. Magnetic simulation was applied to analyse the magnetic flux density of the electromagnetic valvetrain and to optimize the design parameters. Dynamic simulation results show that the proposed hybrid electromagnetic valvetrain with soft-landing control can fully satisfy the valve dynamics in spark ignition engines. Additionally, the utilization of a permanent magnet and an optimal actuating current to catch and release valves has many advantages in energy consumption for valve catching and releasing when compared with other electromagnetic valvetrains.

In this paper, an unthrottled camless engine model, which equipped electromagnetic valvetrain (EMV), has been built for performance simulation of engine dynamics. The combination of the techniques of cylinder deactivation (CDA) and variable valve timing (VVT) has been examined for different engine speeds and engine loads. The results concluded that the mode of two-cylinder deactivation considerably improves the fuel consumption at low engine load. Meanwhile, the one-cylinder deactivation mode is an optimal fuel economy mode for medium engine load. The normal engine mode fairly satisfies the driving torque and fuel economy in a vehicle, and thus it fits the optimal mode for the full loads. Additionally, the results also show that the optimal intake valve closing (IVC) timing for different engine speeds and loads. The IVC timing depends on engine speed linearly while the optimal IVC timing insignificantly changes at different engine loads when CDA is applied. By the determined CDA-VVT strategy, a camless unthrottled engine can maintain high efficiency operation for different speeds and loads.

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