LaunchPoint completing SBIR project on electromechanical valve actuator for fully variable valve system
|Concept of valve implementation on 4-cylinder head. Source: LaunchPoint. Click to enlarge.|
LaunchPoint Technologies, Inc. is completing Phase II of a Small Business Innovation Research (SBIR) grant (IIP-1058556) from the National Science Foundation (NSF) to design and test a novel electromechanical valve actuator designed specifically to control a low-cost, high efficiency valve actuation system that achieves fully variable control over the duration and phase of an engine’s intake valve.
Phase I of the project (NSF SBIR Award No. IIP-0945595) demonstrated a compact, linear-motion actuator capable of driving a typical engine valve. LaunchPoint designed and tested a prototype actuator using the magnetic spring technology originally developed for a high-speed switching mechanism in a space application (US Patent 7,265,470).
Phase I results showed the valve actuator traversing an 8 millimeter trajectory in 3 milliseconds. The data revealed consistent switching trajectories and very smooth landings with speeds less than 0.3 m/sec and almost no oscillations. The Phase II project was aimed at reducing the switching interval even further while improving robustness of the design.
The first-generation valve design supports operation above 6500 rpm when the controller is set for a 2.3 msec full transition across an 8mm lift. The 10%-90% transition time for this controller setting is just 1.35 ms.
The Phase II project also saw the integration of the magnetic valve actuator integrated into a complete engine subsystem. This Magnetic Valve System (MVS) comprises the magnetic valve actuator, an integrated sensor, a control unit, and a power amplifier, which together provide electronic control of the valve timing.
Variable valve timing is desirable for demonstrated improvements in fuel-efficiency, torque, and emissions; however, LaunchPoint says, currently available variable valve timing mechanisms are either too costly or far less effective and robust than desired.
The advantage of LaunchPoint’s technology lies in the high-speed mechanism that recovers the valve’s kinetic energy at the end of each transition from open to closed and vice versa. The stored energy is then released to accelerate the valve on the next transition while also ensuring a soft landing. The low-power electromechanical actuator is used only to “throw” or “catch” the valve at the beginning or the end of the stroke.
Variable valve timing technology has demonstrated a fuel efficiency improvement of up to 20%, torque improvement of 5 to 13%, emission reductions of up to 10% in hydrocarbons, and 40 to 60% in NOx for conventional spark ignition (SI) and compression ignition engines. The demonstrated improvements are even more significant for innovative Homogeneous Charge Compression Ignition (HCCI) engines and Compressed Air Hybrid engines.
For example, the NOx reduction is predicted to be two orders of magnitude lower in comparison to a conventional SI engine with almost zero particulate matter emissions.
Valves of this type can be applied to a wide variety of internal combustion engines. An electromechanical valve actuator eliminates the numerous engine components required for a typical camshaft drive, in turn, decreasing manufacturing and maintenance costs and increasing reliability.
Such valves can be designed into new engines and retrofitted to existing engines. The widespread adoption of these valves would substantially decrease petroleum usage and the associated production of greenhouse gases and air pollution, while also promoting energy independence.
LaunchPoint Technologies Inc. is an engineering services and contract R&D firm with expertise in electromagnetics; control theory; motor and generator design and development; medical device design and development; CFD optimization, and prototyping.
Brian A. Paden, Orlo James Fiske, Michael R. Ricci, Murat Okçuoğlu, David B. Paden, and Bradley E. Paden, Application No. PCT/US2013/022080, January 18, 2013.
Li, L., Tao, J., Wang, Y., Su, Y. et al., (2011) Effects of Intake Valve Closing Timing on Gasoline Engine Performance and Emissions, SAE Technical Paper 2001-01-3564