Experimental Validation of a Cogging Torque Assisted Valve Actuation System for Internal Combustion Engines

Author(s):  
Bradley Reinholz ◽  
Rudolf Seethaler
Author(s):  
Bradley A. Reinholz ◽  
Rudolf J. Seethaler

Electromechanical valve actuation (EVA) for internal combustion engines promises to significantly improve engine efficiency and lower emissions by reducing pumping losses and allowing for novel combustion strategies. However, current designs have not been able to meet the stringent performance criteria for reliability, efficiency, acoustic emissions, weight, and cost that are required by the automotive industry. This paper describes a novel cogging torque assisted motor driven (CTAMD) valve actuation system that promises to meet both the performance and robustness requirements. In contrary to existing EVA systems that recover the kinetic valve energy using a mechanical spring system, the CTAMD system recovers kinetic energy in a magnetic field. This allows for high efficiency while maintaining a simple and elegant electromechanical design. This paper describes the characteristics of CTAMD systems and outlines an electromechanical design for such a system. Then computer simulations of the proposed design are used to demonstrate the expected performance of the system. Finally, the simulated results are compared to other EVA systems to highlight the anticipated improvements.


2011 ◽  
Vol 133 (12) ◽  
Author(s):  
D. T. Hossein Rokni ◽  
Rudolf J. Seethaler ◽  
Abbas S. Milani

In this study, the mechanical design of a fully flexible valve actuation system (FFVA) for intake valves of naturally aspirated internal combustion engines is optimized. The original FFVA design used a connecting rod in order to transform the rotating motion of the actuator to translating motion of the valve. In the improved design introduced here, the connecting rod is replaced by a flexible linkage. This step is taken in order to eliminate wear and play in the mechanical connections. A detailed design procedure is presented to optimize the heavy fatigue load on this element. Simulations and experimental tests are carried out in order to validate the system performance. It is shown that valve trajectory and energy consumption of the actuation system obtained by simulations are consistent with those observed experimentally. The present redesigned FFVA system then provides more reliable valve motion than previously shown designs.


Author(s):  
Hossein Rokni Damavandi Taher ◽  
Rudolf J. Seethaler ◽  
Abbas S. Milani

This study aims to improve the mechanical design of a fully flexible valve actuation system (FFVA) for intake valves of internal combustion engines. Optimization procedures for increasing the reliability and efficiency of the mechanical design of the FFVA system are presented. Simulations and experimental tests are carried out in order to validate the system performance. It is shown that position, velocity and acceleration of the valve obtained by simulations are consistent with those observed experimentally. Furthermore, it is observed that the mechanical vibrations are considerably reduced in the redesigned FFVA system. As a result, current levels and ohmic losses in the electric motor are also reduced. The present redesigned FFVA system then provides more reliable valve motion and better efficiency than the previously shown design [25].


Author(s):  
S J Charlton ◽  
M Shafie-Pour

The paper describes a continuously variable poppet valve actuation system which may be applied to internal combustion engines to render the valve motion controllable while the engine is running. The first phase of a programme to develop the device is described. The results of a rigid-body dynamic analysis are presented followed by a dynamic simulation of the mechanism using a proprietary finite element program. These give an insight into its operation and clarify some of the problems to be solved if the device is to be successfully applied.


Sign in / Sign up

Export Citation Format

Share Document