In sheet metal painting for various applications like Tractor, Automobile, most attractive coating is metallic paints and it is widely applied using 3 coats 2 bake or 3 coat 1 bake technology. Both options, results in high energy consumption, higher production throughput time & lower productivity in manufacturing process. During various brainstorming & sustainable initiatives, paint application process was identified for alternative thinking to reduce burden on environment & save energy. Various other industry benchmarking & field performance requirement studies helped us identify the critical to quality parameters. We worked jointly with supplier to develop mono-coat system without compromising the performance & aesthetical properties. This results in achieving better productivity, elimination of two paint layers, substantial reduction in volatile organic content, elimination of one baking cycle and energy saving.
Plastics are prone to photo oxidative and thermal oxidative degradation under usage conditions due to their chemical nature. From sustainability and cost standpoint, there is an increasing focus on Mold-In-Color (MIC) plastic materials. Simultaneously customer’s expectations on the perceived quality of these MIC parts has been increasing with attractive color and glossy appearance. A study was conducted to analyze the product quality and durability aspects over a prolonged exposure to accelerated weathering condition. Material selected for this study were injection molded specimens of ABS and PC/ABS used in automotive passenger vehicles.
The automotive industry is constantly trying to develop cost effective, high strength and lightweight components to meet the emission and safety norms while remaining competitive in the market. Forging process plays an important role to produce most of the structural components in a vehicle. Precision forging technology is used to produce components with little or no flash leading to elimination of machining process after forging. The load acting on the dies during net or near net forging is very high and leads to wear in the die. In order to have a good die it is important that die wear which is an inevitable phenomenon in a bulk metal forming processes is predicted mathematically. In this study a review on the vast number of studies done in the area of wear and various predictive models is carried out.
Generally brake pads are manufacturing by use of asbestos materials, these materials are chemically harmful and toxic, affects human health. The present investigation fabricates polypropylene composites with mixing constant volume [5 Vol.%] of alumina nano particles and different volume percentages [0%, 5%, 10% & 15%] of basalt fibre by hand layup compression technique. The wear characteristics of polypropylene matrix composites were tested by dry sliding condition using pin on disc apparatus configuration with hardened steel counter-face at elevated temperature. The load was applied 30N to 70N with the interval of 20N and varying of sliding speed 300 rpm to 900rpm with the interval of 300rpm for the time period of 0-180 sec. The wear rate was decreases with addition of alumina nano particle and also increases the frictional force for the effect of basalt fibre content present in the composites. The co-efficient of friction was increases from 0.1 to 0.66 under normal loading condition.
Materials degradation from environmental conditions is a common factor that will often occur in mechanical equipment used in every type of environment. These processes can frequently materialize in unpredicted and harmful ways, especially when they interact and lead to early component damage or failure. This five-session course will summarize the mechanisms that cause materials and mechanical components to degrade in service through exposure to deleterious mechanical and environmental conditions.
In the latest works, we presented the guideline for reducing Metal pick up(MPU,the main component of disc scoring) by controlling the location of the roughness of disc, the brake pad frictioncoefficients and the disc slot's size. In this study, the previously studied iron transfer theory to 'Cu free' brake pad and the disc surface roughness controlling methods which are based on the mass production manufacturing process are applied. It is possible to suggest the ways to improve the scoring-free disc without reducing friction coefficient between the disc and pad, and any demerit such as increased wear and airplane noise like conventional slot discs.
The NVH behavior of disc brakes in particular, is in the focus of research since a long time. Measurements at a chassis dynamometer shows that brake pad wear has a significant influence on the occurrence of low- and high-frequency squealing . It is suspected that high-frequency squealing is more likely to occur when the wear difference between the inner and outer brake linings is small. In the other case, if the differential wear rate between the inner and outer pads becomes higher, the prevalence of low-frequency squealing increases. In order to examine this hypothesis, this work focuses on a simplified model of a commercial brake system . In a first step, the inner pad’s wear is iteratively increased, while the wear on the outer pad remains unaffected. In a second step, the coefficient of friction at the worn pad is iteratively increased to investigate the influence on the low and high-frequency squealing.
One Low-copper formulation and one Copper-free formulation were made into disc pad, and both of them were cured under 4 different conditions. These pads had no backing layer and no scorched layer. Pad thickness, dynamic modulus and natural frequencies were continuously monitored over a period of 12 months. After 12 months at room temperature, pad thickness, dynamic modulus and natural frequencies all increased to higher values. The Low-copper formulation increased rapidly during the first 60 days and the Copper-free formulation increased rapidly for the first 90 days, and then slowly thereafter. Two competing processes are found to be taking place; internal stress relief leading to expansion and cross-linking of the resin leading to shrinkage. As the pad properties are changing continuously, the timing of property measurement becomes an important issue for quality assurance.
Automotive brakes operate under varying conditions of speed and deceleration. In other words, the friction material is subjected to a wide range of normal loads and sliding speeds. One widely accepted test procedure to evaluate, compare and screen friction materials is the SAE J2522 Brake Effectiveness test, which requires full-size production brakes to be tested on an inertia brake dynamometer. For the current investigation, disc pads of two types of 10 different formulations (5 high-copper and 5 copper-free formulations) were prepared for testing on a front disc brake suitable for a pickup truck of GVW 3,200 kg. Each pad had 2 vertical slots, and one chamfer on the leading edge and also on the trailing edge of the pad. One segment of the test procedure looks at the coefficient of friction (Mu) under different brake line pressures and different sliding speeds to determine its stability or variability.
The binder in friction materials (FMs) plays a very crucial role of binding all the ingredients firmly so that they can function efficiently and reliably. The type and amount of binder, both are very critical for manipulating the desired performance properties, which mainly include friction and its sensitivity towards operating parameters, wear resistance, counter-face friendliness, noise, vibration etc. Although a lot is reported on the influence of types of resins on the tribo-performance of FMs, hardly any paper pertains to paint this on a bigger canvas with a more detailed understanding of the amount of resin in FMs on the performance properties including noise. The present study addresses these aspects by developing brake-pads with identical composition, but varying in amount (wt.%) of straight phenolic resins (6, 8, 10 and 12) by compensating the difference by barite, a space filler.
Graphite plays a crucial role in friction materials, since it has good thermal conductivity, lubricity and act as a friction modifier. The right type, amount, shape and size of the particles control the performance of the brake-pads. In this study, particles of synthetic graphite produced in a unique highly controlled graphitization process were selected to develop NAO- Cu-free brake-pads. The four types of pads had identical composition except variation in average particle size of the graphite (60 µm, 120 µm, 200 µm and 400 µm). Physical, mechanical and chemical characterization of the developed brake-pads was done. Tribological performance was studied using a full- scale inertia brake dynamometer following a Japanese automobile testing standard (JASO C406) and noise studies were done on reduced scale prototype following SAE J2521 standard.
The high speed continuous braking distance assessment is the worst condition for thermal fades. This study was conducted to investigate the relationship between fade characteristic and friction materials & brake fluid amount for improving braking distance. So, we used the dynamometer to measure the friction coefficient, braking distance and required brake fluid amount. First of all, we studied the influence of friction coefficient on the same friction material shape (chamfer shape, area of the friction material, number of slots). Secondly, we knew the effects of braking distance by the shape of the friction material. Through these two studies, the shape of the friction material favorable to the fade characteristics was obtained. Finally, we measured the amount of required brake fluid in caliper after 10 consecutive braking cycles through Dynamometer. And then, we measured the amount of compression deformation and uneven wear of the friction material.
Heavy truck brake blocks are found to swell (or expand) permanently during testing or usage, especially so at high temperatures, thus leading to longer durability as measured by thickness loss, similar to light vehicle disc pads. This swelling phenomenon occurs continuously in the layer adjacent to the friction surface during testing or usage; not a one time event. The thickness loss estimated from the weight loss is always greater than measured thickness loss. Brake block wear does not increase linearly with increasing normal load, and the load-sensitivity of block wear is very much dependent on the products. A new test procedure has been developed for generating friction-vs.-temperature and wear-vs.-temperature data at a constant temperature employing intermittent braking on the Chase Brake Lining Quality Tester (SAE J661) and friction material wear can be compared on equivalent-work basis.
A ceramic bound matrix has been investigated to be used as a friction material. The materials were produced by means of ceramic technology, and four formulations were tested by means of a tribometer (pin-on-disc tester) using a gray cast iron counterpart. Test sections included speeds between 1 and 12 m/s, and loads between 25 and 400 N. The characterization of the tribolayers was carried out by means of scanning electron microscopy. The four developed materials were named A, B, C, and D with different ratio of components. They exhibited different wear rates and coefficients of friction. All the materials exhibited sensitivity to speed, while showed a lower sensitivity to load. The coefficient of friction level seems to be suitable for brake applications, oscillating between 0.6 and 0.4, depending on the test section. This kind of materials with further efforts can be possibly useful in future electric vehicles that will not demand large and expensive brakes.
Particulate Matter from Euro 6 Medium Duty diesel engine was analyzed from engine-out, downstream of particulate filter (DPF), and up to the exit of a selective catalytic reactor (SCR) to characterize its chemical and physical nature. Particular attention was devoted to the analysis of particles down to 23 nm. An array of chemical, physical and spectroscopic techniques (Gas chromatography coupled with mass spectrometry (GC-MS), mobility analyzer, UV-visible absorption and fluorescence spectroscopy) was applied for characterizing the organic particulate matter (PM, constituted of polycyclic aromatic hydrocarbons (PAH), heavy aromatic compounds, soot) in the exhaust. The engine was operated at “full-load” (100% of the total power, representing the best performance of the engine operation) condition, and at different engine speeds. Results showed that the DPF efficiency was greater than 96% in the reduction of the sub 23 nm particles across the speeds range.
The transient heat transfer behavior of a real size automotive catalytic reactor has been simulated with OpenFOAM in 1D. The model takes into consideration the gas-solid convective heat transfer, axial wall conduction and heat capacity effects in the solid phase, but also the chemical reactions of CO and C3H6 oxidations, based on simplified Arrhenius and Langmuir-Hinshelwood approaches. The associated parameters have been chosen based on the tuning of experimental data. The impact of different initial catalytic converter temperatures, inlet flow temperatures and inlet flow rates have been quantified, even in terms of overall cumulative emissions. . A dimensional analysis is proposed and dimensionless temperature difference and space-time coordinate are defined. Using this suitably modified coordinates, for the case of negligible axial solid conduction, computed solid temperature at the reactor outlet lay on the typical S-curve.
In this paper, computation fluid dynamics (CFD) simulations are performed to describe the effect of in-cylinder flow structures on the formation and oxidation of soot in a swirl-supported light-duty diesel engine. The focus of the paper is on the effect of swirl motion and injection pressure on late cycle soot oxidation. The structure of the flow at different swirl numbers is studied to investigate the effect of varying swirl number on the coherent flow structures. These coherent flow structures are studied to understand the mechanism that leads to efficient soot oxidation in late cycle. Effect of varying injection pressure at different swirl numbers and the interaction between spray and swirl motions are discussed. The complexity of diesel combustion, especially when soot and other emissions are of interest, requires using a detailed chemical mechanism to have a correct estimation of temperature and species distribution.
BSVI Norms getting implemented in India by April 2020 and every heavy commercial vehicle OEMs viewing it as one of the greatest challenge, there are many factors and trade off that should be considered at every step of the project. The newly developed engine in BSVI will be equipped with actuators like Intake Throttle Valve, Exhaust Throttle Valve and combination of these flap operations with turbocharger output plays a prominent role in controlling performance and emission. Turbocharger selection plays major role in engine and vehicle performance on road and testcell. Turbo charger plays an apex role in providing both required boost to the engine performance and set up a control on emissions. This study focusses on the use of different AVU (Air Valve Unit) controlled waste gate turbochargers from different suppliers and how it’s getting matched with the engine performance requirements.