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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.

In recent years, the push for reduced product development timelines has been more than ever with significant changes in the automotive market. High electrification, intelligent vehicle systems and increased number for car manufacturers are a few key drivers to the same. The front loading of development activities is now a key focus area for achieving faster product development. From vehicle dynamics point of view availability of subjective evaluation feedback plays a key role in optimization various system specifications. This paper discusses an approach for front loading through parallel development of the tire and vehicle chassis system, using advanced simulation and driving simulator technology. The proposed methodology uses virtual tire models which in combination with real-time vehicle model enables subjective evaluation of vehicle performance in driver-in-loop simulators.

Light weighting is an effective strategy in increasing energy efficiency in the automotive industry. In this paper, mass reduction with cost benefit was targeted in an exterior trim panel. Polypropylene copolymer (PPCP) compound was developed for a large exterior trim panel (1400 X 700mm) having an integrated grill mesh. The part had challenging requirements in terms of slow speed impact, structural durability, dimensional stability, aesthetics, thermal ageing resistance, cold impact resistance, scratch resistance and weathering resistance. By having ultra-high flow behavior, optimum tensile strength, modulus, impact strength and thermal properties, the PPCP compound met the requirements for a thin wall exterior trim panel with a thickness of 2.6mm. Structural durability of the design was validated by virtual engineering. Part design and material combinations with better tooling design iterations were analyzed by using mold flow analysis.

In today’s automobile industry where BS6 emission is posing a high challenge for aggregate development, cost control and with limited timeline. The main target is to provide the cooling system to have less impact on the in terms of cost, weight and to meet the challenging engineering requirement. Thus, the frugal engineering comes into the picture. This paper shows the application of thermosyphon principle for UDM injector cooling thereby reducing the rotation parts and power consumption such as an electric pump. Thermosyphon is a method of passive heat exchange and is based on natural convection, which circulates a fluid without the necessity of a mechanical or electric pump. The natural convection of the liquid commences when heat transfer to the liquid gives rise to a temperature difference from one side of the loop to the other.

PVC (polyvinylchloride) synthetic leather or called leatherette is being widely used for automotive interior applications for seat cover, gear boot, gap hider, steering wheel and roof liner due to their leather like feel and texture, flexibility, sewability, affordability, and wide design freedom. However, the leatherette construction such as top coating, backing fabric and fabric weaving pattern plays a critical role in the finished leatherette performance for the specific application. This study provides the influence of different coating material and different backing fabric in squeak behavior of gear boot PVC leatherette. The squeak behavior was studied by stick slip test as per automotive engineering requirements, and the response of these coating and fabric surface was measured in the form of Risk Priority Number (RPN).

In manual transmission, the vital function of synchronizer pack is to synchronize the speed of the target gear for smooth gear shifting. The synchronizer pack consists of various elements and each of these elements has specific function. These elements are baulk rings, shifter sleeve, hub, synchro key, synchro springs etc. The function of synchronizer can be affected due to failure of any one of these elements. This work focuses on the failure of synchronizer pack due to synchro spring failure. The function of synchronizer spring is to exert the required force, to index the synchronizer ring before the movement of shifter sleeve over synchronizer ring. During the shifting of shifter sleeve from one gear to another gear, the springs deflect in both shifting directions. This causes fatigue failure of synchronizer springs. The manufacturing variations, and part quality issues results in very early fatigue failure of synchronizer springs.

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.

In automotive Body-In-White (BIW) structures, stiffness and the fatigue behavior is greatly influenced by the properties of its joints. Spot welding is one of the most widely used process for joining of sheet metals in BIW. Spot weld fatigue life under Accelerated Durability Test (ADT) is crucial for durability performance of BIW structures. Experience of BIW validations highlighted more number of spot weld failures in CAE when compared to actual tests. Hence, lot of iterations in the form of design modifications are required to be carried out to make these spot welds meet the targets which increases design & development time as well as cost. Current practice uses force-based approach for predicting spot weld fatigue life in CAE. To improve the spot weld fatigue life correlation, extensive study has been carried out on the approaches used for calculating spot weld fatigue life, namely force & stress-based approaches.

The automobile industry is going through one of the most challenging times, with increased competition in the market which is enforcing competitive prices of the products along with meeting the stringent emission norms. One such requirement for BS6 phase 2 emission norms is monitoring for partial failure of the component if the tailpipe emissions are higher than the OBD limits. Recently PM (soot) sensor is employed for partial failure monitoring of DPF in diesel passenger cars.. PM sensor detects soot leakage in case of DPF substrate failure. There is a cost factor along with extensive calibration efforts which are needed to ensure sensor works flawlessly. This paper deals with the development of an algorithm with which robust detection of DPF substrate failure is achieved without addition of any sensor in the aftertreatment system.

Model based calibration is extensively used by the automotive OEMs (Original Equipment manufacturers) because of its correlation accuracy with test data and freezing the operating parameters such as injection timings, EGR rates, fuel quantity etc. The prediction of Brake specific Fuel consumption (BSFC), Exhaust and intake temperatures are very close to test data. The prediction of Brake specific NOx is directionally reliable with acceptable tolerance.

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.

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.

Present day AMT unit uses two high pressure hydraulically operated pistons for select & shift operations which make the unit weigh around 8kg. Besides this it also makes the unit more complex & unreliable with a lot of torque interruption. The use of electrical servo motors steps in here as a better alternative as it provides a more precise and smoother shift. To test this we used a 5-MT Transmission. For the selection, a precise 14.5 degree of twisting was required which was easily achieved by the servo motor. Further, shift of 10.5mm could be made possible by using the motor to shift the rack using a pinion on the shaft. This system then essentially eliminates the whole hydraulic circuit, the housing of actuator pack & power pack making it a simpler unit all together. Thus, it offers an uninterrupted torque path from the engine to vehicle which allows for a seamless gearshift. This seminal paper provides an introduction to the technology together.

Present day AMT unit uses two high pressure hydraulically operated pistons for select & shift operations which make the unit weigh around 8kg. Besides this it also makes the unit more complex & unreliable with a lot of torque interruption. The use of electrical servo motors steps in here as a better alternative as it provides a more precise and smoother shift. To test this we used a 5 Gear-Manual Transmission. For the selection, a precise 14.5 degree of twisting was required which was easily achieved by the servo motor. Further, shift of 10.5mm could be made possible by using the motor to shift the rack using a pinion on the shaft. This system then essentially eliminates the whole hydraulic circuit, the housing of actuator pack & power pack making it a simpler unit all together. A Motor is attached to the output shaft of the Transmission which drives in power while the AMT unit is making transition from one gear to another.

Hydraulic Load sensing brake valves are used in vehicles from a long time in the market. They proportionate the rear brake line pressure according to the rear axle load in order to avoid the rear wheel lock during braking. During the actual test of the Hydraulic load sensing valve on a subject vehicle, there was drop in performance against its expected peak brake performance. In the current work a detailed analysis is made to understand the sensitivity of the load sensing valve & its effect on the vehicle performance. The parameters affecting the valve sensitivity along with vehicle level factors affecting the performance are analysed during the work.

In automotive product development, design and development of the chassis plays an important role since all the internal and external loads pass through the vehicle chassis. Durability, NVH, Dynamics as well as overall vehicle performance is dependent on the chassis structure. Even though passenger vehicle chassis has a ladder frame or a monocoque construction, small commercial vehicle chassis is a hybrid chassis with the cabin welded to the ladder frame. As mileage is critical for sale of SCVs, making a light-weight chassis is also important. This creates a trade-off between the performance and weight which needs to be optimized. In this study, a parametric beam model of the ladder frame & the cabin of the vehicle is created in COMSOL Multiphysics. The structure has been parameterized into the long member & crossmember geometry & sections. The model calculates the first 12 natural frequencies, global stiffness, and weight.

New trend in steering system such as EPS is coming up, but still hydraulic power steering system is more prevalent in today’s vehicles. Power steering pump is a vital component of hydraulic power steering system. Failure of steering pump can lead to loss of power assistance. Prediction of hub load on pump shaft is an important design input for pump manufacturer. Higher hub loads than the actual designed load of pump bearing may lead to seizure of pump. Pump manufacturer has safe limits for hub load. Simulations can assist for optimization of belt layout and placement of accessories to reduce the hub load. Lower hub load can have direct effect on improvement of pump durability. This paper deals with dynamic simulation of belt drive system in MSC.ADAMS as well as vehicle level measurement of hub load on power steering pump.

Modern day automotive market demands shorter time to market. Traditional product development involves design, virtual simulation, testing and launch. Considerable amount of time being spent on virtual validation phase of product development cycle can be saved by implementing machine learning based predictive models for key performance predictions instead of traditional CAE. Durability oil canning loadcase for vehicle hood which impacts outer styling and involves time consuming CAE workflow takes around 11 days to complete analysis at all locations. Historical oil canning CAE results can be used to build ML model and predict key oil canning performances. This enables faster decision making and first-time right design. In this paper, prediction of buckling behaviour and maximum displacement of vehicle hood using ML based predictive model are presented. Key results from past CAE analysis are used for training and validating the predictive model.

Exhaust system is one of the complex automotive systems in terms of performance and strength prediction due to combination of transient mechanical and thermal loads acting on it simultaneously. Traditionally, most of automotive vehicles have exhaust systems with hot end mounted on engine and cold end mounted on chassis or BIW through hangers. A new powertrain mounted exhaust system was developed in-house. This exhaust system underwent validation and evaluation during development phase. Durability concerns were observed on exhaust system in Track test and gear shift durability test. This paper focuses on identifying the root cause of these concerns based on the failures observed during evaluation in Accelerated Durability (ADT) and gear shift durability (GSD) tests. Based on the architecture and packaging space challenges in vehicle, engine is mounted on two mounts and a roll restrictor. Muffler, which has higher inertia, is mounted at higher offset with respect to engine rolling axis.

This paper describes modified polypropylene copolymer (PPCP) material for thin wall front bumper development (2.5 mm) with integrated grill in automotive application. This compounded PPCP material has optimized flow behavior, tensile strength, modulus, impact strength, and thermal properties to meet the functional requirements. This is a ready to mold material used in injection molding process. Front bumper and grill are functional components with slow speed impact requirement to absorb impact in real world. These parts have precise fitment requirement under sun load condition. Front bumper is also having other critical criteria with respect to vehicle variants such as aesthetic mold-in-color finish as well as painted finish. Grill has air entry performance criteria to ensure cooling efficiency in intercooler compartment.