Download or read book Hydraulic Variable Valve Actuation on a Single Cylinder Engine written by Mohammad Sharif Siddiqui and published by . This book was released on 2017 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combustion characteristics in an engine cylinder can greatly change over a range of speeds and loads. However, conventional engines x the timing and amount of intake and exhaust, which can lead to higher emissions, wasted fuel, and lower power output. This thesis studies the application of a hydraulics based variable valve actuation system to change the valves' lift and timing on a single cylinder spark ignition engine. In addition to controlling the valve actuation, a hydraulics based design has the advantage of protecting against engine failure in cases of electrical power loss, reverting the system to behave as a conventional camshaft valve train. The research extends the previous iterations of the hydraulics design to prevent leakage, retain pressure, and reliably open and close the engine valves. A hydraulic cylinder is used to replace the conventional cam where pressurized fluid opens, and spring force closes, the engine valve. The pressurized fluid is supplied to, or removed from, the cylinder using rotary spool valves coupled to the engine crankshaft. Additionally, the system is modelled in Simulink to determine the effect of system pressure, flow area, and spring rate on the resulting valve pro file. After modelling the system's performance for achieving variable lift and timing, the system was designed, manufactured, and tested on a single cylinder engine with the aid of a dynamometer. Experimental results for valve lift showed good agreement with the simulation models. Majority of the tests were performed using manual control, followed by experiments with active control of the system pressure to reach a desired valve lift. The lift controller is able to achieve the desired valve actuation in under 2 seconds with active pressure feedback. Lastly, the ability of the hydraulic variable valve system as a viable alternative is shown by achieving combustion at 1500 RPM engine idle speed.

Download or read book Hydraulic Variable Valve Actuation System written by Mitchell Terpstra and published by . This book was released on 2019 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventional engines with camshafts with fixed timings force a compromise between performance at high engine loads and fuel economy at low engine loads. Adjusting internal combustion engine valve timing and lift through a variable valve actuation (VVA) system is an established method of improving engine performance [1]. A fully flexible hydraulic variable valve actuation (HVVA) system in development at the University of Waterloo allows the valve timing to be optimized for any engine operating condition. This project is a further development of this HVVA system. First, the previous prototype was thoroughly tested and evaluated. Major design issues and challenges were addressed, and changes were incorporated into a new prototype design. This prototype was designed to be robust and more compact than the previous system. A completely new concept was developed for the phasing system used to adjust the valve timings. The new HVVA design was manufactured, assembled, and installed on a single cylinder test engine. Initial experiments of the new HVVA system validated its ability to change engine valve timing and match the profiles of different VVA strategies. The system was able to switch between different profiles in

Download or read book Cost Effectiveness and Deployment of Fuel Economy Technologies for Light Duty Vehicles written by National Research Council and published by National Academies Press. This book was released on 2015-09-28 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt: The light-duty vehicle fleet is expected to undergo substantial technological changes over the next several decades. New powertrain designs, alternative fuels, advanced materials and significant changes to the vehicle body are being driven by increasingly stringent fuel economy and greenhouse gas emission standards. By the end of the next decade, cars and light-duty trucks will be more fuel efficient, weigh less, emit less air pollutants, have more safety features, and will be more expensive to purchase relative to current vehicles. Though the gasoline-powered spark ignition engine will continue to be the dominant powertrain configuration even through 2030, such vehicles will be equipped with advanced technologies, materials, electronics and controls, and aerodynamics. And by 2030, the deployment of alternative methods to propel and fuel vehicles and alternative modes of transportation, including autonomous vehicles, will be well underway. What are these new technologies - how will they work, and will some technologies be more effective than others? Written to inform The United States Department of Transportation's National Highway Traffic Safety Administration (NHTSA) and Environmental Protection Agency (EPA) Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emission standards, this new report from the National Research Council is a technical evaluation of costs, benefits, and implementation issues of fuel reduction technologies for next-generation light-duty vehicles. Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles estimates the cost, potential efficiency improvements, and barriers to commercial deployment of technologies that might be employed from 2020 to 2030. This report describes these promising technologies and makes recommendations for their inclusion on the list of technologies applicable for the 2017-2025 CAFE standards.

Download or read book Variable Valve Actuation written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R & D expertise in the valve train area. Historical R & D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the mechanism it was determined that the single cam design did not have enough flexibility to satisfy three critical OEM requirements simultaneously, (maximum valve lift variation, intake valve opening timing and valve closing duration), and a new approach would be necessary. After numerous internal design reviews including several with the OEM a dual cam design was developed that had the flexibility to meet all motion requirements. The second cam added complexity to the mechanism however the cost was offset by the deletion of the electric motor required in the previous design. New patent applications including detailed drawings and potential valve motion profiles were generated and alternate two cam designs were proposed and evaluated for function, cost, reliability and durability. Hardware was designed and built and testing of sample hardware was successfully completed on an engine test stand. The mechanism developed during the course of this investigation can be applied by Original Equipment Manufacturers, (OEM), to their advanced diesel engines with the ultimate goal of reducing emissions and improving fuel economy. The objectives are: (1) Develop an optimal, cost effective, variable valve actuation (VVA) system for advanced low temperature diesel combustion processes. (2) Design and model alternative mechanical approaches and down-select for optimum design. (3) Build and demonstrate a mechanism capable of application on running engines.

Download or read book Design and Development of a Regenerative Hydraulic Variable Timing Engine Valve Actuator written by William E. Tourdot and published by . This book was released on 2002 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regenerative Hydraulic Variable Valve Actuator for Internal Combustion Engines written by Ahmad M. Sabri and published by . This book was released on 1999 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydraulic Variable Valve Actuation Unit for a Diesel Engine written by Chris Dollimore and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cylinder Filling Control of Variable Valve Actuation Equipped Engines written by Leroy Thomas and published by Omniscriptum. This book was released on 2010-10 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of torque and pollutants of Variable Valve Actuation equipped internal combustion engines found in the automotive industry (both Diesel and gasoline engines) is studied. Variable Valve Actuation (VVA) is a technology which has been introduced to optimize engine efficiency at steady-states covering a wide range of operating conditions. In more details, the outcome of the internal combustion engine (torque and pollutant) depends on the cylinder filling at each stroke which, itself, depends on the VVA positions and the engine intake manifold conditions. These two subsystems have inconsistent response times which results in efficiency losses during transient operations. In this manuscript, a remedy for this issue which takes the form of coordination loops of low-level controllers is proposed. This coordination uses a cylinder filling model, designed in the thesis. Experimental results prove that torque production and pollutant emissions can be improved.

Download or read book Power and Fuel Economy Optimization of Unthrottled Spark ignition Engines Using Highly Flexible Hydraulic Variable Valve Actuation System written by Yangtao Li and published by . This book was released on 2018 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Variety of technologies along with the mechanisms for their implementations have been developed in order to pursue possible improvements in the performance and efficiency of gasoline engines. Yet, most of the commonly used techniques, such as the cam-based variable valve timings (VVT) and variable compression ratio (VCR), are realized by different kinds of complicated mechanisms, providing an extended but still relatively limited adjustability, for attaining improved valve timings and different engine cycles according to the varying working conditions of the engine. The hydraulic variable valve actuation (HVVA) system, however, can provide greater freedoms to the engine valve motions than most of the traditional cam-based valve train systems do. By considering the characteristics of the HVVA system, the strategies of putting its outstanding flexibilities into use for further improving the performances of gasoline engines with respect to power and fuel economy are developed in this research. By utilizing the flexibility offered by the HVVA system, a set of new valve motion strategies is developed for realizing an unthrottled engine load control. In this research, the late exhaust valve closure (LEVC) and early intake valve closure (EIVC) strategies are adopted at the same time for granting the engine an internal exhaust gas recirculation (IEGR) feature and together evolved into a tunable IEGR scheme for fulfilling the partial engine loads without throttling. Alternatively, the realization to the proposed variable Atkinson cycle (VAC), which is realized by late intake valve closures (LIVCs), can also achieve the same goal of unthrottled engine load control for partial load operations. Moreover, an HVVA engine model is proposed and built in GT-suite, which is able to capture the interdependencies of the HVVA system and the engine operations, and is as well carefully calibrated by experimental data acquired from individual bench tests of the HVVA system and the baseline engine. The HVVA engine in this research is a converted from a baseline single-cylinder engine and is able to carry out a variable Otto cycle (VOC) at full engine load operations for achieving higher power performance while realizing a variable Atkinson cycle (VAC) or a tunable IEGR feature at partial engine load operations for gaining better fuel economy without having any further modifications or attaching additional components to the engine. In addition, a set of genetic algorithm (GA)-based optimization schemes is also developed for identifying the proper operating parameters of the HVVA engine when adopting any of the proposed engine operation schemes. A MATLAB-Simulink and GT-Suite coupling simulation structure is proposed for carrying out the GA approaches. Furthermore, these GA optimizers are designed to be capable of maintaining their proper functionality while non-linear constraints are taken into considerations. By running the HVVA engine with the optimized operating parameters identified by the proposed GA optimizations, noticeable improvements on the engine outputs at full load operations and fuel economy at partial load operations are revealed. Benefited from the features of the HVVA system, the tunings of the HVVA engine can be flexibly customized to fulfill any requirements towards different desired engine characteristics. At last, with the corresponding operating parameters be optimized by the proposed GA optimization techniques, all the proposed HVVA valve motion strategies are carried out by an actual prototype HVVA engine and are qualitatively validated by experiments. The experimental results are showing expected outcomes on the improvements to the engine's power and fuel economy performances under corresponding operations. A power improvement of 12.3% is noticed from the experiments by running the HVVA engine in the proposed VOC operation at the exemplary 1000rpm engine speed. In addition, comparing to the throttled operation of the baseline engine, the experiment studies show also the HVVA engine is able to run with leaner air-fuel mixtures to achieve the same desired partial engine load operations by adopting the IEGR scheme or the VAC operation. With an adopted air-fuel ratio (AFR) of 16.1 for the IEGR scheme and 16.3 for the VAC scheme, the engine could realize the same exemplary speed-load operation of 1000rpm/5.2Nm, while the baseline engine with throttling load control requires an AFR of 14.7 to achieve the same partial load operation.

Download or read book Development of a New Fully Flexible Hydraulic Variable Valve Actuation System written by Mohammad Pournazeri and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The automotive industry has been in a marathon of advancement over the past decades. This is partly due to global environmental concerns about increasing amount of air pollutants such as NOx (oxides of nitrogen), CO (carbon monoxide) and particulate matters (PM) and decreasing fossil fuel resources. Recently due to stringent emission regulations such as US EPA (Environmental Protection Agency) and CARB (California Air Resource Board), improvement in fuel economy and reduction in the exhaust gas emissions have become the two major challenges for engine manufacturers. To fulfill the requirements of these regulations, the IC engines including gasoline and diesel engines have experienced significant modifications during the past decades. Incorporating the fully flexible valvetrains in production IC engines is one of the several ways to improve the performance of these engines. The ultimate goal of this PhD thesis is to conduct feasibility study on development of a reliable fully flexible hydraulic valvetrain for automotive engines. Camless valvetrains such as electro-hydraulic, electro-mechanical and electro-pneumatic valve actuators have been developed and extensively studied by several engine component manufacturers and researchers. Unlike conventional camshaft driven systems and cam-based variable valve timing (VVT) techniques, these systems offer valve timings and lift control that are fully independent of crankshaft position and engine speed. These systems are key technical enablers for HCCI, 2/4 stroke-switching gasoline and air hybrid technologies, each of which is a high fuel efficiency technology. Although the flexibility of the camless valvetrains is limitless, they are generally more complex and expensive than cam-based systems and require more study on areas of reliability, fail safety, durability, repeatability and robustness. On the contrary, the cam-based variable valve timing systems are more reliable, durable, repeatable and robust but much less flexible and much more complex in design. In this research work, a new hydraulic variable valve actuation system (VVA) is proposed, designed, prototyped and tested. The proposed system consists of a two rotary spool valves each of which actuated either by a combination of engine crankshaft and a phase shifter or by a variable speed servo-motor. The proposed actuation system offers the same level of flexibility as camless valvetrains while its reliability, repeatability and robustness are comparable with cam driven systems. In this system, the engine valve opening and closing events can be advanced or retarded without any constraint as well as the final valve lift. Transition from regenerative braking or air motor mode to conventional mode in air hybrid engines can be easily realized using the proposed valvetrain. The proposed VVA system, as a stand-alone unit, is modeled, designed, prototyped and successfully tested. The mathematical model of the system is verified by the experimental data and used as a numerical test bench for evaluating the performance of the designed control systems. The system test setup is equipped with valve timing and lift controllers and it is tested to measure repeatability, flexibility and control precision of the valve actuation system. For fast and accurate engine valve lift control, a simplified dynamic model of the system (average model) is derived based on the energy and mass conservation principles. A discrete time sliding mode controller is designed based on the system average model and it is implemented and tested on the experimental setup. To improve the energy efficiency and robustness of the proposed valve actuator, the system design parameters are subjected to an optimization using the genetic algorithm method. Finally, an energy recovery system is proposed, designed and tested to reduce the hydraulic valvetrain power consumption. The presented study is only a small portion of the growing research in this area, and it is hoped that the results obtained here will lead to the realization of a more reliable, repeatable, and flexible engine valve system.

Download or read book Hydraulic Variable Valve Timing Testing and Validation written by Matthew Chermesnok and published by . This book was released on 2016 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis documents the development of a fully continuous, hydraulics-based variable valve timing system. This hydraulics based variable valve timing system is capable of controlling an engine valves lift height and infinitely varying the engine valves lift profile. Along with full valve controllability during normal operation, the variable valve timing system is capable of providing the same operation as a classic cam shaft under engine power loss conditions. This is possible due to the rotating hydraulic spool valves coupled to the engines crank shaft, which are used to actuate the engine poppet valves. The main focus of this thesis is to investigate, alter and implement a new iteration of the hydraulic variable valve timing system on a standalone test bench to validate the systems operating principles. The test bench utilizes servo motors to act as an engines crank shaft which runs the rotating hydraulic spool valves and hydraulic pump. This serves as an intermediate step to full engine implementation of the variable valve timing system. The research begins by analyzing the current mechanical spool valve and hydraulic cylinder design for any potential problems that may occur either during assembly or full operation. The basic system equations are presented to give a glimpse into the working principles of the rotary valves. The mechanical, electrical, and hydraulic subsystems are discussed in terms of what was considered during the design and implementation process. Then design changes that were performed on the rotary valve system to overcome any failures. Lastly the resulting data is presented from the current variable valve timing design to verify proper system functionality.

Download or read book Variable Valve Actuation and Control written by Society of Automotive Engineers and published by . This book was released on 1993 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Green Technologies and the Mobility Industry written by Andrew Brown and published by SAE International. This book was released on 2010-11-16 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book features 20 SAE technical papers, originally published in 2009 and 2010, which showcase how the mobility industry is developing greener products and staying responsive - if not ahead of - new standards and legal requirements. These papers were selected by SAE International's 2010 President Dr. Andrew Brown Jr., Executive Director and Chief Technologist for Delphi Corporation. Authored by international experts from both industry and academia, they cover a wide range of cutting-edge subjects including powertrain electrification, alternative fuels, new emissions standards and remediation strategies, nanotechnology, sustainability, in-vehicle networking, and how various countries are also stepping up to the "green challenge". Green Technologies and the Mobility Industry also offers additional useful information: the most recent Delphi Worldwide Emissions Standards booklets, which will be shipped with the print version of this title, or as part of the PDF download, if you purchase the ebook version. Exclusive Multimedia Package Watch Dr. Andrew Brown, Jr. describe the new trends in green mobility. Download a free SAE presentation on green technologies and the mobility industry. Challenging times: an interview with Dr. Andrew Brown, Jr. Buy the Set and Save! This book is the first in the trilogy from SAE on "Safe, Green and Connected" vehicles in the mobility industry edited by Dr. Andrew Brown, Jr. This trilogy can be purchased in a combination of the following sets: Green Technologies and Active Safety in the Mobility Industry Green Technologies and Connectivity in the Mobility Industry Active Safety and Connectivity in the Mobility Industry Buy the Entire 3 Volume Set to Save the Most! Green, Safe & Connected: The Future of Mobility

Download or read book Tribological Processes in the Valve Train Systems with Lightweight Valves written by Krzysztof Jan Siczek and published by Butterworth-Heinemann. This book was released on 2016-06-17 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tribological Processes in Valvetrain Systems with Lightweight Valves: New Research and Modelling provides readers with the latest methodologies to reduce friction and wear in valvetrain systems—a severe problem for designers and manufacturers. The solution is achieved by identifying the tribological processes and phenomena in the friction nodes of lightweight valves made of titanium alloys and ceramics, both cam and camless driven. The book provides a set of structured information on the current tribological problems in modern internal combustion engines—from an introduction to the valvetrain operation to the processes that produce wear in the components of the valvetrain. A valuable resource for teachers and students of mechanical or automotive engineering, as well as automotive manufacturers, automotive designers, and tuning engineers. Shows the tribological problems occurring in the guide-light valve-seat insert Combines numerical and experimental solutions of wear and friction processes in valvetrain systems Discusses various types of cam and camless drives the valves used in valve trains of internal combustion engines—both SI and CI Examines the materials used, protective layers and geometric parameters of lightweight valves, as well as mating guides and seat inserts

Download or read book New Generation of Engine written by Pierre Duret and published by Editions OPHRYS. This book was released on with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Official Gazette of the United States Patent and Trademark Office written by United States. Patent and Trademark Office and published by . This book was released on 2002 with total page 1370 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Advances in Materials and Modern Manufacturing written by I. A. Palani and published by Springer Nature. This book was released on 2022-05-26 with total page 1129 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the select proceedings of the fourth International Conference on Advanced Materials and Modern Manufacturing (ICAMMM 2021). It covers broad areas such as advanced mechanical engineering, material science and manufacturing process. Various topics discussed in this book include green manufacturing, green materials, Industry 4.0, additive manufacturing, precision engineering, sustainability, manufacturing operations management and so on. Given its contents, the book will be useful for students, researchers, engineers and professionals working in the area of mechanical engineering and its allied fields.