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The paper describes the design and development of a five speed gearbox for the Royal Enfield ‘Bullet’ range of motorcycles and a four speed + reverse variant for industrial, light car and similar applications. The design specification for the five speed gearbox called for a directly interchangeable unit with the sting Bullet four speed gearbox, providing either right or left-hand gear shifting, to meet local market preferences/statutory requirements worldwide. Provision was also required for either ‘up-for-up’ or ‘up-for-down’ gear shift patterns, with the minimum of special-to-option parts. Within these demanding spatial and functional requirements, the design produced is not materially heavier and has greater load capacity than the current four speed gearbox. The four speed + reverse variant utilises the same major castings and has all but a few components common or very similar to the parent five speed gearbox.

With a number of vehicles being developed in the country and implementation of safety standards becoming mandatory, proving of a vehicle for safety is becoming an area of high priority in India. Keeping this in view, a gravity sled facility has been established at ARAI for simulated crash testing. This paper describes the facility and its establishment as well as the development of suitable stopping devices to meet various applications. The risk of injury to the occupants in the event of crash is severe when structural deformation/breakage occurs in the vehicle interior, seat anchorages and the restraint systems. A simulated crash test facility such as sled is used for the development of these systems and their evaluation. This is the prescribed procedure for certification. Instead of using a complete vehicle crash facility, use of a simulated crash facility becomes cost effective. The simulated crash facility described here uses the gravity principle for acceleration of sled.

The duration for the development of a new vehicle model is continuously decreasing. This does not permit adequate time for proving component assemblies and vehicles to be evaluated for durability by conventional measures. However, increasing competition and quality consciousness calls for an assured life with a high degree of confidence. This has forced the test engineers to look for techniques for accelerating the durability evaluation. The technique calls for concepts for compressing the evaluation time. This can be achieved by compression in both time as well as frequency domain. Further, it also calls for correct techniques for the mixing of roads, extrapolation of data acquired over a small distance to the vehicle life, evaluation and elimination of non or less damaging inputs, etc. This paper reviews some of the existing techniques and describes case studies of how accelerated testing can be applied in vehicle development.

One of the primary concern during assessment of structural integrity of vehicle bodies is the quality of joints used therein. The increased trend in vehicle weight reduction (through use of thin sheet panels) calls for more critical evaluation of the quality of such joints. The electric Resistance Spot Welding (RSW) is one of the largely used joining process for vehicle body structure. Besides the quality of sheet metal, the quality of RSW joints is largely governed by the process parameters e.g. weld current, hold time, squeeze time etc. The quality of RSW joints for durability can be assessed by mechanical strength and fatigue life. The paper presents a methodology for durability assessment of such joints using laboratory specimens and arriving at optimum values of process parameters to maximise the fatigue life. The methodology presented makes extensive use of Design of Experiment (DOE) techniques for better reliability of the results.

Computational Analysis and Engineering using P-Cat, WAVE, HeatCad, Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) are sequentially applied to design, develop, and optimize catalytic converter. P-Cat is used to estimate back pressure due to substrates, end cones, and inlet/outlet pipes. WAVE simulation is used to predict the exhaust system back pressure from the engine headface to tail pipe to estimate engine performance. Heatcad, a transient heat transfer analysis is used to simulate the temperature response in the exhaust system to locate the catalytic converter to achieve maximum performance. Heatcad analysis provides the easy way to identify thermal management issues and to design and optimize the runner lengths, material thicknesses of the manifold and downpipes.

Engineers have traditionally relied on subjective assessment and intution during the development and troubleshooting of a vehicle's ride characteristics. For example, while terms such as ‘soft’ or ‘hard’ can convey a qualitative description of an automobile suspension, they are of little use to design engineer. From this need for a design tool, the field of ride quality analysis has emerged. As an introduction to objective ride quality analysis, this presentation provides an overview of the philosophy behind ride comfort models, the way they are applied, and the benefits that may be realized from their use. A correlation study of user surveys with measurements will be reviewed in this work and the most universally accepted ride comfort model, the NASA model, will be explored. When coupled with a repeatable testing methodology, this model can provide a solid foundation for comparative analysis and effective optimization of a vehicle's ride behavior.

The instrumentation requirements in the area of automotive testing has increased many folds owing to the increasing and stringent demands imposed by several regulatory bodies such as the BIS, CMVR, EEC, etc. The type of tests to be carried out depends upon the purpose of evaluation such as for certification, design validation, etc. The parameters to be evaluated pertaining to the testing of vehicles are many. Presently, a number of dedicated instruments are being employed for the above purpose, each instrument meant to carry out evaluation of a specific parameter. However, one of the major disadvantages in such instruments is that their functionality is rigid and is difficult for reconfiguration. Also, it requires the adjustments of many hardware components to achieve the desired functional behaviour.

Today, NVH characteristics are vital to satisfying the demands of modern internal combustion engine. For this purpose, forged crankshaft has been applied unexceptionally to engine instead of cast crankshaft. So, Hyundai Motor Company (HMC) developed new forged crankshaft to improve NVH characteristics in the new V6 engine. But, Forged V6 crankshaft has limitation of cosmetic form because of complexity of its die parting line. HMC's new forged V6 crankshaft with 6-counterweights was developed through optimized design for low cost, high stiffness, easy productibility and compact size. This new crankshaft acquired the patent in many countries.

This paper describes the comparison of overall performance of different tractor engines using utility factors & weightages factors for various performance parameters which may be very much conflicting in nature e.g. some could be lower the better (like Brake mean effective pressure, Vibration level, work severity and specific fuel consumption, etc.) while the others (like Power, Back-up torque & Benefit size, etc.) are the higher the better. Also there are practical limitations on each parameter and they influence each other. Hence, to rate an engine on the overall utility front for any specific application like tractors, automobiles etc, these limitations are overcome by first categorizing them in different groups and than an overall value is derived which is unit free and therefore applicable to all.

Evaluation of structural durability has always been a key issue in product development. It is a time consuming element in the development cycle. Exploring fatigue life prediction analysis capabilities, using computer based digital processing techniques, at an early design stage can reduce the development period dramatically. Fatigue sensitivity is an analysis tool to evaluate effect of a design parameter on durability of the component or product under study. The technique was effectively used to analyse parameters like stress concentration, welding geometry, loading environment, etc. The paper discusses how fatigue sensitivity analysis was carried out on different structural components of two wheeled vehicles like chassis, engine link, mounting accessories, welded components, etc. It also describes how the methodology was useful in pinpointing causes of the likely failure, in arriving at simple but very effective modifications, etc.

Experimental identification of structural dynamics models is usually based on the modal analysis approach. In the classical modal parameter estimation approach, the baseline data which are processed are Frequency Response Functions measured in laboratory conditions. However, in many applications, the real operating conditions may differ significantly from those applied during the modal test. Hence, the need arises to identify a modal model in operational conditions. This issue is even more complicated by the fact that in most cases, only response data are measurable while the actual loading conditions are unknown. Therefore, the system identification process will need to base itself on output-only data.

The increasing number of End-of-Life-Vehicles (ELVs) as well as the increasing use of plastic parts in vehicles is leading to an ever increasing burden on the environment (caused by waste). Not only ELVs but also manufacture and use of vehicles gives rise to waste. Apart from the avoidance of waste this problem can only be solved by the continuous development of dismantling and recycling technologies as well as by the establishment of an economic market for this. To guarantee this a neutral supervision of the processes is necessary as well as the engagement of the automotive industry and possibly the introduction of new legal requirements. The neutral supervision offers, therefore, an effective contribution to a clean, environmentally conscious and safe future.

In a multi-cylinder engine, the harmonics of pressures in different cylinders add to excite the crankshaft and other mass-elastic system in its line. The predominant component builds up the shear stress at resonances of the system, if the natural frequencies lie in the operating range. Addition of a tuning disc in the form of a rubber damper increases the order of the system by one. The nuisance frequency is substituted by two new damped frequencies. The design of rubber for operating at high temperatures and for withstanding high shear is important. The known procedure of calculations is systematically reviewed in this paper. The importance of properties of rubber is given in detail. A successful study of damping a large 8.8 litre turbocharged and aftercooled engine rated at 2200 rpm is used to demonstrate the procedure to design a rubber damper.

The Indian authorities have put in emission legislation norms for 2-wheelers that will result in widespread use of exhaust catalysts on 2-stroke powered vehicles by 2000. A number of 2-wheelers from the Indian market were used to examine fuelling and catalyst variables. Reducing carburetor jet size resulted in leaner operation and improved tailpipe emissions, particularly for CO. Increasing catalyst size and cell density gave emission improvements, however, higher cell densities could increase back pressure resulting in richer operation and higher CO levels. The effect of catalytic metal type and concentration was established. In addition, the important deactivation mode of ignition misfire leading to excessive catalyst temperatures was examined experimentally and this has resulted in some important guidelines for catalyst selection and extent of permissible misfire, which can improve catalyst life in service.

To ensure that vehicles meet the ISO 362 pass - by requirements before they are introduced in the market their transient noise radiation must also be tested under laboratory conditions. The paper describes a Time Domain Holography based method for localization, quantification and ranking of sound generating regions on vehicles under run-up (i.e. non-stationary) conditions. A case study on a tyre illustrates some of the possibilities with the new technique.

India 2000 norms, equivalent to Euro I, add a new dimension to emission legislation. Particulate matter (PM) is an additional parameter to be reckoned with. Higher injection pressures are required to achieve the particulates target, apart from combustion chamber and swirl optimisation. The objective of any application work is to meet the more stringent emission requirements without any compromise on fuel consumption. Mainly inline pump size ‘A’, a versatile and economical system at present, is in use in the majority of commercial applications in India and distributor pumps (VE) will be used to meet the India 2000 legislation. An analysis of the experiences encountered during the application on diesel engines and trends for future injection systems are discussed in this paper.

Year 2000 emission norms for Indian passenger cars, which have been notified requires major changes in the existing technologies being used in the passenger car vehicles on roads. Electronic fuel injection systems and catalytic converters are being used extensively abroad to meet stringent emission regulations. Even in India, major joint ventures in passenger car segment have introduced vehicles with single-point / multi-point fuel injection systems. It has become difficult to meet the mandated emission regulations with the conventional mechanical carburetted vehicles. Automotive Research Association of India alongwith M/s UCAL Fuel Systems has developed an electronic feedback carburettor system to use alongwith catalytic converter for a passenger car to meet the year 2000 emission norms. A closed loop system has been designed and developed which takes the input from a λ-sensor output and controls the additional air added in the intake manifold of the engine through a stepper motor.

A three-wheeler is a symbol of mobility at low cost for a common man in India. Due to high loading compared to its 2-wheeler counterpart, the 3-wheeler emit higher emissions and serious efforts are being made by the manufacturer to minimize the emissions. ARAI and Emitec have undertaken a Technology Demonstrator Project to investigate the application of metallic substrates and Emitubes for a typical carburetted 2-stroke 3-seater 3-wheeler with an aim to introduce a cost effective practically viable option of reducing exhaust emissions to meet INDIA 2000 emission norms. Now-a-days, there are 3-wheelers available which are offering lower emissions levels. It was the intention of the authors, not to use such a clean vehicle for a better demonstration of the efficiency of current catalyst technology. Here, a 3-wheeler manufactured in 1996 has been selected, for which a converter is designed employing a software developed by Emitec.

Development of suitable engine mounting system, during vehicle development, by experimental methods is a time consuming process. Due to various constraints on design parameters it's difficult to apply all theoretical considerations in the design process. To simplify and expedite the design process a computer simulation tool is developed using ADAMS. The effect of various design parameters on the eigen frequencies and vibrations transferred to chassis is studied. With the help of parametric model optimum mount configurations can be selected. The potential of alternative mount configurations can be compared also.

It is easier and more economical to conduct R49 13-mode cycle emission tests in engine test bed compared to chassis dynamometer ECE R83 test. This is because of costlier test equipment for chassis dynamometer and requirement of separate dynamometers for various categories of vehicles, even when connected with the same engine. Two methods have been attempted for predicting ECE R 83 cycle emissions from R49 test results based on the extensive emission trials conducted in both engine and chassis dynamometers. The first method is by using the modified weightage factors applied to each mode results of R49 test. While the second method uses the mapped ECE R 83 load/speed points for a particular configuration of vehicle and translating them to nearest load/speed point of R49 cycle. The predicted emission values conform well to the actual chassis dynamometer results.