Refine Your Search



Search Results

Technical Paper

Weight Reduction of Shifter Forks using Steel Inserts

Shift quality of a manual transmission is a critical characteristic that is requires utmost care by the designers while structuring the transmission. Shift quality is affected by many factors viz. synchronizer design, shift fork design, shifter design, gear design, transmission oil selection etc. Designers have realized that shift fork is critical element for improving shift feel of a transmission. This paper focuses upon the reduction in weight of the overall transmission shift system by using steel inserts in aluminum shifter forks. No compromise on the stiffness and strength of the shift fork of a manual transmission is done. Stiffness and strength of shifter fork is optimized using contact pattern analysis and stiffness analysis on MSC Nastran. All the subsystem (i.e. synchronizer and the shift system component) are constrained to optimize the shift fork stiffness. A 5-speed manual transmission is used as an example to illustrate the same.
Technical Paper

Vibro-Acoustic Optimization of 4 Cylinder Diesel Engine Oil Pan Structure for Lower Sound Radiation.

By reducing overall noise emanating from Engine at design phase, permits to reduce both time-to-market and the cost for developing new engines. In order to reduce vibration and radiated noise in engine assembly, oil pan is one of the most critical components. This study explains the key-steps that are executed to optimize the oil pan design for 4-cylinder diesel engine by improving Normal Modes, modified Topology, reduced Forced Frequency Response and ATV analysis for reducing its noise radiation. Using Multi-body tool crankshaft forces were generated and the FE model of Base Design was analysed for its noise radiation and panel contribution was done for finding the most radiating panels using Boundary Element Method approach. A series of iterative optimization were carried out with commercial software. Parameters like Stiffness, material property, Ribbing patterns and Shape of the Oil pan was modified to shift the natural frequencies of the component and reduce the sound radiation.
Technical Paper

Vehicle Sway Prediction in Hydraulic Circuit Failed Condition on 4 Wheeled Vehicle with ‘X’ Split Brake Configuration

A 4 wheeled vehicle with X-split brake configuration, in hydraulic circuit failed condition will have a behavior of induced sway due to braking force variation in the front and rear diagonally. With increasing vehicle speed, engine power & customer expectations, the situation becomes more critical and challenging in designing a brake system which caters in meeting the homologation requirement at an expense of vehicle sway within controllable limits of driver / customer. This paper proposes a novel approach & methodology to overcome the above situation by predicting the effect of brake force distribution variation on the vehicle swaying behavior during circuit failed braking condition. This study will quantify vehicle sway, caused due to imbalance in brake force distribution during a circuit failed braking event on X Split configuration vehicles.
Technical Paper

Understanding the Stick Slip Behavior of Plastics and Target Setting: An OEM Perspective

Automotive OEMs are aggressively using different materials for interiors due to value proposition and variety of options available for customers in market. Excessive usage of different grade plastics with zero gap philosophy can cause stick slip effect leading to squeak noise. Even though systems and subsystems are designed using best practices of structural design and manufacturing tolerances, extreme environmental conditions can induce contacts leading to squeak noise. Appropriate selection of interface material pairs can minimize the possibilities of squeak conditions. Stick-slip behavior of different plastics is discussed in the present study, along with critical parameters during material compatibility testing in a tribological test stand. Friction coefficient of different material pairs for a defined normal load and sliding velocity are analyzed for patterns to recognize squeaks versus time.
Technical Paper

Turbocharging a Small Two Cylinder DI Diesel Engine - Experiences in Improving the Power, Low End Torque and Specific Fuel Consumption

Turbocharged common rail direct injection engines offer multiple benefits compared to their naturally aspirated counterparts by allowing for a significant increase in the power and torque output, while simultaneously improving the specific fuel consumption and smoke. They also make it possible for the engine to operate at a leaner air/fuel mixture ratio, thereby reducing particulate matter emission and permitting higher EGR flow rates. In the present work, a two cylinder, naturally aspirated common rail injected engine for use on a load carrier platform has been fitted with a turbocharger for improving the power and torque output, so that the engine can be used in a vehicle with a higher kerb weight. The basic architecture and hardware remain unchanged between the naturally aspirated and turbocharged versions. A fixed geometry, waste gated turbocharger with intercooling is used.
Technical Paper

Tractor Transmission Validation for Synchronizer as Skid at Rig Level

Synchronizer design optimization is being prime need for smooth gear shifting and shifting noise. Especially in tractors, synchronizers are subjected to different kinds of loads under various field applications such as Puddling, Cultivation, Haulage, Construction equipment, etc. Also, transmission housings act as a part of chassis of the tractor and hence subjected to sever bending loads. Thus, design & evaluation of tractor transmission, meeting the customer requirement is quite complex. Current trends in product development are driven by shortening development time, reduced cost and first-time-right principle. These above requirements drive tractor manufacturers to put more efforts on delivering quality, robust and reliable transmission assembly in time. Generally the synchronizer packs were validated at sub system level in test rig and further assembled on to the tractor to validate the same in tractor level it requires more time & high cost.
Technical Paper

Torsional Vibration Analysis of the Driveline on Light Weight Rear Wheel Drive Vehicle

Globally the customers are demanding more powerful yet silent vehicles to enhance their daily commuting and goods transportation needs. The current trend in the design is to enhance the engine power without major change in the physical configurations of the engine systems. Increasing the power and torque of the powertrain will have an undesirable and adverse effect on NVH levels. In this research work, a light weight rear wheel drive vehicle was investigated from torsional vibration perspective. The vehicle is powered by a two cylinder engine with turbo charger. The power and torque of the vehicle was increased approximately two times with the help of turbocharger which resulted in increasing the powertrain torsional vibration. This increased vibration was further amplified through inevitable driveline resonances which causes severe vibration at the passenger seat location and steering. Also, the noise levels are above the comfortable zone.
Technical Paper

Test Methodology for Objective Evaluation of Cornering Lamps on Automotive Passenger Vehicles

With the advancement in vehicle technology over the years, many intuitive technologies are coming in automotive passenger vehicles to improve the safety aspects during vehicle driving in night conditions. In addition to headlamps, cornering lamps or infrared camera with head up display etc. are evolving as a part of AFS (Advanced Front Lighting Systems) to aid driver vision. Many OEMs are following conventional methodology of subjective assessments with the ratings on different numerical scale mapped with customer acceptance to validate head lamps and its tech updates. These methods lag in getting repeatability of results, acceptance reliability and not knowing the limitations of the installed system due to high dependency on the selected evaluators. This paper emphasizes on robust test methodology development to validate the complete performance of cornering lamps with the objective test data analysis.
Technical Paper

Sustainable Polyurethane Composite with Coconut Fiber for NVH Applications

With increasing growth of vehicular population, there is an increasing demand for raw materials. This has added strain to the available resources, which is becoming more and more unsustainable. As a result, search for sustainable materials are continuously happening in our industry and there is a strong focus from everyone to incorporate more and such materials. One way of doing so, is by blending naturally available materials like fibers, with polymers. In this study, naturally available Coconut fibers have been blended successfully with Polyurethane foam, thereby improving the green footprint of the vehicle. Coconut fibers are naturally occurring fiber extracted from the husk of the coconut. Polyurethane foam is the most versatile polymeric foam used in several places of automobile for reducing the Noise, Vibration & Harshness. The composite was manufactured using reaction injection molding technique by reacting polyol with iso-cyanide.
Technical Paper

Suspension Strain Correlation Using Flex Bodies in MBD

Automotive Suspension is one of the critical system in load transfer from road to Chassis or BIW. Using flex bodies in Multi body simulations helps to extract dynamic strain variation. This paper highlights how the MBD and FE integration helped for accurate strain prediction on suspension components. Overall method was validated through testing. Good strain correlation was observed in dynamic strains of constant amplitude in different loading conditions. Combination of different direction loading was also tested and correlated. Method developed can be used in the initial phase of the vehicle development program for suspension strength evaluation. Suspension is one of the important system in vehicle which is subjected to very high loading in all the directions. To predict the dynamic stresses coming on the suspension system due to transient loads, faster and accurate method is required. To accelerate the suspension design process it become necessary to get good accuracy in the results.
Technical Paper

Study of Optimal Magnification for Retained Austenite Evaluation in Low carbon Case Hardening steel Using Metallurgical Microscopy

This study on optimum magnification at which Retained austenite to be evaluated by comparing the difference in determining the retained austenite in low carbon carburizing alloy steel using the optical metallurgical micrographic method and X-ray diffraction method. The retained austenite phase will be in surface and color is white in nature also its presented in between the martensite needles. It can be distinguished as separate micro-constituents by using image analyzing software. In another method the RA measurements were carried out on the surface by PROTO iXRD Retained austenite measuring system using Cr K radiation. The (211) and (200) reflections of Martensite and (220) and (200) reflections of Austenite were made for this estimation. However, the calculated values of retained austenite by metallurgical microscope in different magnifications are not identical.
Technical Paper

Study of Intake and Exhaust System Acoustic Performance Refinement with the Help of Vibro-Acoustic Analysis Tool

Increase in customer's awareness for better vehicle NVH has prompted automobile industry to address NVH issues more seriously. Among other critical vehicle systems for NVH, Air Intake and Exhaust Systems play an important role in terms of passenger compartment noise, sound quality and vehicle pass-by noise. Hence proper design & development of these systems is imperative to reduce their contribution in overall vehicle NVH. This needs to be achieved within constraints of meeting other functional requirements such as emissions and engine performance. The design parameters one needs to look at while developing the intake and exhaust system are mainly the acoustic transmission loss, structural noise radiations from the surfaces and structural isolation between body and these systems. This paper demonstrates the use of FEM approach for Vibro-Acoustic Analysis as a practical means for design of intake and exhaust system in terms of high transmission loss.
Technical Paper

Study of Energy Absorbing Front Cabin Mount, Its Stiffness Balance with Chassis and Test Correlation in Frontal Impact of Commercial Vehicle Cabin

During design and development of a cabin for any commercial vehicle, meeting the strength requirements of front impact as per Indian regulation (AIS-029) is a very critical milestone. AIS-029 regulation consists of three destructive tests, i.e. Front Impact Test (Test A), Roof Strength (Test B) and Rear Wall Strength (Test C). Study of energy absorbing front cabin mount, its stiffness balance with chassis and CAE correlation with physical test is demonstrated in this study. [1]
Technical Paper

Split Type Crankcase Design for a Single Cylinder LCV Diesel Engine

Serious efforts have been put in space to focus on lowering the fuel consumption and CO2 discharge to the environment from Automotive Diesel Engines. Though more focus is put on material up gradation approach on weight perspective, it is accompanied by undesirable cost increase and manufacturing complexity. As a part of development of a single cylinder engine for a light commercial vehicle application, a unique approach of integrated split type crankcase design is designed and developed. This design have addressed all the key factors on Weight, Cost and Manufacturing perspectives. The split type crankcase configuration, particularly middle-split configuration, integrates the oil sump, front cover and flywheel housing in a single unit beneficial from the point of view of reducing engine weight and thus reducing the manufacturing costs. This crankcase is also excellent from the serviceability point of view.
Technical Paper

Simultaneous Reduction of NOx and PM Emissions through Low Temperature EGR Cooling in Diesel Engines

In this paper, Authors tried to investigate the influence of Low Temperature EGR (LtEGR) on NOx, PM emissions and fuel efficiency in NEDC 120 cycle. Sports Utility Vehicle (SUV) less than 3.5T vehicle selected for investigation of LtEGR. The existing water cooling circuit modified to suitable to handle the LtEGR concept without changing the existing EGR cooler. Cooled EGR technology has two benefits in terms of handling high EGR ratios and more fresh air within the engine displacement. Under this assumption separate LtEGR layout was prepared for the evolution of superior EGR cooling technologies and low pressure EGR.
Technical Paper

Simulations Based Approach for Vehicle Idle NVH Optimization at Early Stage of Product Development

The noise and vibration performance of diesel fueled automotives is critical for overall customer comfort. The stationary vehicle with engine running idle (Vehicle Idle) is a very common operating condition in city driving cycle. Hence it is most common comfort assessment criteria for diesel vehicles. Simulations and optimization of it in an early stage of product development cycle is priority for all OEMs. In vehicle idle condition, powertrain is the only major source of Noise and Vibrations. The key to First Time Right Idle NVH simulations and optimization remains being able to optimize all Transfer paths, from powertrain mounts to Driver Ear. This Paper talks about the approach established for simulations and optimization of powertrain forces entering in to frame by optimizing powertrain mount hard points and stiffness. Powertrain forces optimized through set process are further used to predict the vehicle passenger compartment noise and steering vibrations.
Technical Paper

Silent Block Bush Design and Optimization for Pick-Up Truck Leaf Spring

Structural elastomer components like bushes, engine mounts are required to meet stringent and contrasting requirements of being soft for better NVH and also be durable at different loading conditions and different road conditions. Silent block bushes are such components where the loading in radial direction of bushes are high to ensure the durability of bushes at high loads, but has to be soft on torsion to ensure good NVH. These requirements present with unique challenge to optimize the leaf spring bush design, stiffness and material characteristics of the rubber. Traditionally, bushes with varying degree of stiffness are selected, manufactured and tested on vehicle and the best one is chosen depending on the requirements. However, this approach is costly, time consuming and iterative. In this study, the stiffness targets required for the bush were analysed using static and dynamic load cases using virtual simulation (MSC.ADAMS).
Journal Article

Shifter Fork Stiffness Correlation to Gear Shift Quality

Shift quality of a manual transmission is a critical characteristic that requires utmost care while structuring the transmission. Shift quality is affected by many factors viz. synchronizer design, shifter design, gear design, transmission oil selection etc. This paper presents a correlation between stiffness of the shift fork in manual transmission with the gear shift quality using a gear shift quality assessment setup. Stiffness of shifter fork is optimized using contact pattern analysis and stiffness analysis on MSC Nastran. All the subsystem (i.e. synchronizer and the shift system component) are constrained to optimize the shift fork stiffness. A-5-speed manual transmission is used as an example to illustrate the same. A direct correlation of gear shift fork stiffness with the shift force experienced by the driver is established. The shift system was modeled in the UG NX 6.0 software to collate the synchronization force, shift system gap etc with the constraint on the shift fork.
Technical Paper

Shift Rail Interlock Design, Simulation and Analysis for Shift Force Transfer to the Shifter Finger

Interlock mechanism have found multiple uses in the shift system of a manual transmission. It can either be used to block every other rail from moving other then the active shifting rail or it can be used to bring all rails in neutral positions. As a designer the aim is to make systems more compact and efficient in its functionality. This desire to have a compact shift system results in the design of an interlock ball mechanism which allows the use of a single shift finger for two different rails. To validate this design a 5 speed manual transaxle was used, in which the 5th rail and the reverse rail are combined in a single shift finger. Between the rails a single 8mm interlock ball is used to transmit the shifting force to the rails from the shift finger. After a complete analysis of the profile for every degree of gradient the model was manufactured for testing on bench setup established for shifting tests. Various tests were performed and the system was tested and validated.
Technical Paper

Setting of Inspection Parameters for Automotive Transmission Parts in Various Bench Tests

This paper deals with setting of Inspection parameters for selected automotive transmission parts in various bench tests. This paper we are discuss about critical dimension's measured for particular type of test. It is not possible to measure all the dimensions of a component for doing a particular test. This is due to time constraints set by program delivery deadlines. From above statement it can be deduced that it is almost impossible to measure all dimensions of a component. A bench level test may consist of two major tests. They are maximum load test and gear shift durability test. The maximum load test deals with gear box durability test and torque carrying capacity of gearbox. Parameters to be measured for some of above parts will be identified. More importantly it will also identify see reasons for that parameter to be measured.