Design and Experimental Implementation of an Electromagnetic Engine Valve Drive

Abstract

In conventional internal combustion engines, engine valve displacements are fixed relative to crankshaft position. If these valves were actuated as a variable function of crankshaft angle, significant improvements in fuel economy could be achieved. To this end, a new type of electromagnetic valve drive system (EMVD) for internal combustion engines was more recently proposed. This EMVD incorporates a disk cam with a very desirable nonlinear profile which that functions as a nonlinear mechanical transformer. Modeling and simulation results showed significant advantages of this EMVD over previously designed electromagnetic engine valve drives. In this articles, we describe an experimental implementation of the proposed EMVD, which was developed to confirm these benefits. The EMVD apparatus was designed, constructed, and integrated into a computer-controlled experimental test stand. The experimental results confirm the benefits of using a nonlinear mechanical transformer in a motordriven engine-valve spring system, as seen in the small average power consumption and low valve seating velocity. In addition, a valve transition time sufficient for 6000-rpm engine operation was achieved. The results also suggest ways to improve the EMVD apparatus in the future.

Comparative Analysis Between <i>Cam</i> and <i>Cam-less</i> Valve Actuating for Automotive System

“…The novel model for the camless lift profile is presented in (21). This model has the ability to depict different engine lift profiles.…”

“…The experimental camless system data in Table 1 [21], was imported into MATLAB and with CF Toolbox app and (21) was realized. (21), we obtained figure 9.…”

Nonlinear System Modeling, Optimal Cam Design, and Advanced System Control for an Electromechanical Engine Valve Drive

“…The NMT is implemented by a slotted cam and a roller follower in the slot which are connected to the motor shaft and the valve stem respectively, as shown in Figs. 3 The mechanical transformer with an intentionally nonlinear characteristic leads to attractive features including soft landing at the end of transitions, low torque requirement during transitions, and zero power consumption between transitions [13][16]- [19]. A key feature of the NMT is zero-slope at both ends of the stroke.…”

“…The peak-topeak value is the rotation range, while the frequency is chosen to meet the transition time requirement. [19]. In the experiment, the motor drive current is limited to 18 ± A due to thermal constraints on the motor.…”

A Multilevel Inverter Bridge Control Structure with Energy Storage Using Model Predictive Control for Flat Systems

“…Nevertheless, practical tests show that this actuator structure is not always effective for a large variety of applications because a complex control structure is needed to control such a valve [18]. Recently, for instance, a new type of electromagnetic valve drive system has been proposed and described [19]. This paper presents the control design for a novel permanent-magnet linear valve actuator for use in a variable engine control to allow short-stroke and high-dynamic motions.…”