Design Analysis and Development of Aluminium Cylinder Block with Slip-Fit Cylinder Liners for High Performance New Generation Passenger Car Diesel Engine

Abstract

<div class="section abstract"><div class="htmlview paragraph">The global automotive industry is growing rapidly in recent years and the market competition has increased drastically. There is a high demand for passenger car segment vehicles with high torque delivery and fuel economy for a pleasant drivability experience. Also, to meet the more stringent emission requirements, automakers are trying very hard to reduce the overall vehicle gross weight. In lowering both fuel consumption and CO₂ generation, serious efforts have been made to reduce the overall engine weight. An engine cylinder block is generally considered to be the heaviest part within a complete engine and block alone accounts for 3-4% of the total weight of the average vehicle, thus playing a key role in weight reduction consideration. Aluminum casting alloys as a substitute for the traditional cast iron can mean a reduction in engine block weight between 40 and 55% [<span class="xref">9</span>], even if the lower strength of aluminum compared to grey cast iron is considered. Thus, designers of aluminum engine blocks are constantly striving to design better and lighter blocks in order to improve and enhance the efficiency of automobile engines.</div><div class="htmlview paragraph">This work is a part of design and development of 2.2 L, 4-cylinder turbocharged intercooler (TCIC) diesel engine for a complete new monocoque vehicle platform, focused on automotive passenger car application with high operating in cylinder combustion pressures around 190 bar. The paper portrays the effective system approach essential for selecting aluminum as the choice of material, selection of alloy composition, casting process, heat treatment and key design criteria. The ongoing substitution of cast iron in engine blocks by aluminum casting alloys also requires the design and development of a new “tribological” system. Selection of cost-effective cylinder liner system and the drawbacks of this heterogeneous concept such as the lack of metallic bonding with the surrounding cast aluminum alloy and higher bore distortion are addressed during design and development. Statistical database, quality tools like design failure mode and effect analysis (DFMEA), design for manufacture and assembly (DFMA) etc., classical design methods, finite element analysis (FEA), advanced computer-aided engineering (CAE) and computational fluid dynamics (CFD) simulation tools have helped in materializing this concept into production. Experimental validation of the design is carried out as a part of design verification and validation. And results are elaborated to show the effectiveness of integrated approach used for the development program.</div></div>