Design of Innovative Engine Valve: Background and Need (original) (raw)
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Design of Innovative Engine Valve
This is part two of the paper on conceptual design of an engine valve. The previous paper describes the background and the need of an engine valve for an internal combustion engine. The present state of the engine valve technology and the innovations incorporated in its design has been described. This paper presents the conceptualization of an innovative valve train aiming at lesser number of components, reduction in friction and wear, proper sealing, and trimming down pumping losses. Various geometric designs of valve trains have been detailed and compared. Finally a convolution based poppet valve mechanism, which is free from numerous mechanical elements like camshaft, cam, push rod, rocker arm and rocker bearing has been recommended. Finite element analysis of convoluted spring has been carried out to ascertain safe limits in terms of stresses and achieving desirable valve lift. Magnetorheological fluid and electromagnet are used to vary the valve-lift.
A review of new technologies in valve systems of internal combustion engines and their effects
IOP Conference Series: Materials Science and Engineering
Efficient use of energy is becoming increasingly crucial due to global warming and depleting fossil fuel sources. Automotive manufacturers aim for fuel economy, reduction of exhaust emissions, durability, volume and weight reduction, and power and torque increase in internal combustion engines. One of the most important developments in this field is the new technologies in classic valve systems. There are still ongoing studies in this field as the gas exchange processes affects all engine parameters. In this review; the principles of new technologies used on classic valve systems and their effects on engines have been investigated. The research has shown; new mechanism technologies used on valve systems have positive effects on engine performance, power, torque and fuel consumption.
Novel Spring-Buffered Variable Valve Train for an Engine Using Magneto-Rheological Fluid Technology
Frontiers in Materials
Vehicle manufacturers have been attempting to increase engine efficiency and decrease pollution through various methods. Variable valve actuation technology is one of these methods. Several mechanisms have been established already and have been used to develop this technology. However, these systems have common problems such as complex design, large volume, low response rate, and high-energy consumption. In this study, a novel variable valve actuation device that is compact and requires less energy was developed using magnetorheological (MR) fluid technology. The main components used in this device are an MR valve, passive buffer spring, cam, and rocker arm. This study was divided into three parts. First, an MR valve train was designed. This valve train can be constructed easily, and has fewer hydraulic and mechanical components and consumes less energy than other technologies. Second, the magnetic plate block design was optimized to obtain the required control force at optimal volume and energy. Finally, dynamical simulations pertaining to the springs and the structure were executed to analyze the dynamic condition of the valve. The simulation results indicated that the proposed MR valve could effectively provide functions of variable valve timing and variable valve lift (VVL) by dynamically controlling the external current in the magnetic coil.
Performance evaluation of a magnetorheological fluid variable valve
Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 2007
The present paper describes the conceptual design, simulation, and fabrication of a magnetorheological (MR) fluid variable-valve actuation (WA) system. Two set-ups, one for testing the conceptual design and the other for application of the MR valve on a real engine, have been developed. The test set-up measures the displacement of the valve, which operates by the cam-follower mechanism. The results of valve lifts at different speeds and control currents are presented. To implement the MR fluid VVA system, a four-stroke single-cylinder Kirloskar TV1 vertical diesel engine has been selected. Inlet and exhaust manifolds have been modelled to estimate volumetric efficiency. The equations governing the unsteady air flow in the ducts have been solved using the method of characteristics. A numerical code to simulate the entire gas exchange process has been developed, and the results have been compared with the experimental results. Further, this code has been used to identify the optimal v...
Modelling the Valvetrain of the Car Engine to Study the Effects of Valve Rotation
Applied Sciences, 2022
The valve performs an alternating translational motion along its axis of symmetry, which is accompanied by a rotation about its own axis, possibly due the valve body’s cylindrical geometry and due to the conjugate element, the guide, which is also a cylindrically shape body. By ensuring this rotational motion of the valve, a number of advantages are obtained, mainly related to the increase of the operating period of the valve and implicitly of the engine. Following the critical analysis of the current state of research on the valvetrain systems and the rotational motion of the valves, the advantages and the disadvantages of valve rotation during engine operation were established. To this end, it has been established that, in addition to the theoretical approach to the problem, it is necessary to create a virtual model of the valvetrain mechanism to do a thorough analysis of the problem. Based on the model, the influence of the camshaft speed, temperature and lubricating oil pressure...
ASME Open Journal of Engineering
The poppet valve is by far the most widely used in cylinder head design of internal combustion (IC) engines; however, poppet valves themselves create significant flow restrictions during both the intake and exhaust strokes, thus causing a reduction in volumetric efficiency that affects overall engine performance. By removing the restrictive poppet valve from the flow path of air into and out of the cylinder head and allowing air to flow unobstructed, any given IC engine can achieve greater volumetric efficiency and higher specific output. The Vaztec ECOREV rotary valve system utilizes straight-cut flow passages that reduce such restrictions. This rotary valve system is designed to be directly driven by the crankshaft, thereby replacing the camshaft and poppet valve system altogether. This paper will primarily explore the differences in flow characteristics between this rotary valve and a conventional poppet valve cylinder head using both computational fluid dynamics (CFD) and flow b...
Design of magneto-rheological (MR) valve
Grunwald Artur and Olabi Abdul Ghani Design of Magneto Rheological Valve Sensors and Actuators a Physical 148 Pp 211 223 Issn 0924 4247, 2008
Magneto-Rheological Fluid ("MRF") technology has been successfully employed in various low and high volume automotive applications. Good understanding of specific design constraints is required to define and to optimize a magneto-rheological device. This article presents parametrical analyses with magnetic simulations, of a magneto-rheological valve and a magneto-rheological orifice. Experimental rig assemblies of two different control devices have been designed, built and the performances have been evaluated experimentally. Controlled pressure drops, of 0.6 MPa @ 4.5 A at 5 cm 3 /s in the orifice mode, and 1.5 MPa @ 4.5 A at 0 cm 3 /s, in the valve mode, using MRF132-AD, have been achieved. The study shows that excellent features like the fast response and the contactless nature of MRF control are attractive for various control devices.
Combustion Engines, 2013
According to the current trend to reduce the valvetrain movable masses in combustion engines lightweight valves are used increasingly. They can be made of light alloys from the TiAl alloy group or of ceramic materials such as silicon nitride. They are often coated with additional protective layers to reduce the resistance of friction or the wear intensity. They may also be a hollow structure made of steel with internal reinforcing ribs. Compared to traditional full steel valves they are characterized by different temperature gradients when working in a valvetrain. As a result, their working change, particularly the intensity of the heat transfer and wear. The paper presents valve models developed with the FEM technique for several design and material configurations for lightweight intake and exhaust valves operating under conditions similar to those made of steel. Also the temperature gradients of the discussed valves have been included and compared to those of full steel valves.
Modelling and validation of a fast switching valve intended for combustion engine valve trains
Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, 2002
In recent years much research has been done in the area of variable-valve actuation in order to improve the eYciency of combustion engines. Currently, a number of diVerent concepts for variable-valve actuation are under development or at a prototype stage. Hydraulic actuation has been an obvious candidate, but the lack of suYciently fast switching valves with appropriate owrates has been the major shortcoming. Design of such highly dynamic systems requires accurate models of the actual included components.
Design and performance analysis of magnetorheological valve module with annular-radial concept
ARPN journal of engineering and applied sciences, 2015
In this study, a new design of magnetorheological (MR) valve module using annular-radial gaps concept are developed to improve the design flexibility and manufacturability towards commercialization process. In commercial perspective, a product with flexible performance capacity is sometimes more preferable than a high performance product but with fixed specifications since frequent design resizing can be inefficient in terms of manufacturing process. This paper proposes a new design of a compact MR valve using annular-radial concept as an effort to enhance the performance of an MR valve while at the same time improving the easiness of performance range and the simplicity of manufacturing process using a fully modular valve structure. In order to evaluate the valve performance, the conceptual design module MR valve, the proposed design is evaluated in terms of pressure drop characteristics with respect to the magnetic field strength and current input in the perspective of module perf...