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This paper discusses the development of an all speed governed diesel-natural gas dual fuel engine for agricultural farm tractor. A 45 hp, 2.9 liters diesel-natural gas dual fuel engine with a novel closed loop secondary fuel injection system was developed. A frugal approach without any modification of the base mechanical diesel fuel injection system was followed. This approach helped to minimize the cost impact, while meeting performance and emissions at par with neat diesel operation. Additional cost on gas injection system is redeemed by cost savings on diesel fuel. The dual fuel technology developed by Mahindra & Mahindra Ltd., substitutes on an average approximately 40% of diesel with compressed natural gas, meeting the TREM III A emission norms for dual fuel while meeting all application requirements. The governing performance of the tractor was found to be superior than base diesel tractor.

Rotavator is an active tillage implement for breaking the Soil and for the preparation of seed bed for cultivation. The Farmers are currently facing problem due to usage of sub optimal speed of Rotavator which results in more fuel consumption, takes more time for completion of operation. Also, the Current Rental models work on Tractor + Implement as rental combination and customer not able to rent Rotavator as a standalone implement due to non-availability of Tracking information such as hours of utilization on Rotavator. Farmers not able to maintain the service periodicity, if oil change not done in prescribed duration then it may result in improper maintenance and breakdown of the Rotavator. To overcome these problems a smart Rotavator developed consists of an electronic unit fitted on the Rotavator shaft to measure the speed of the shaft rotation and in turn convert to Rotavator speed and also able to convert into Hours of usage based on the starting and stopping of the rotavator.

Being a safety critical aggregate, every aspect of brake system is considered significant in vehicles operations. Along with optimum performance of brake system in terms of deceleration generation, brake pedal feel or brake feel is considered as one of the key elements while evaluating brake system of vehicles. There are many factors such as liner and drum condition, road surface, friction between linkages which impress the pedal feel. Out of these, in this paper we will be discussing the factors which influence the brake pedal feel in relation to the driver comfort and confidence building. Under optimum braking condition, brake operation must be completed with pedal effort not very less or not very high, brake pedal feel must be firm throughout the operation, in such a way that it will not create fatigue and at the same time it will give enough confidence to the driver while operating with acceptable travel.

As the FTP-75 drive cycle does not have a prescribed gear shift pattern, automotive OEMs have the flexibility to design. Conventionally, gear shift pattern was formulated based on trial and error method, typically with 10 to 12 iterations on chassis dynamometer. It was a time consuming (i.e. ~ 3 to 4 months) and expensive process. This approach led to declaring poor fuel economy (FE). A simulation procedure was required to generate a gear shift pattern that gives optimal trade-off amongst conflicting objectives (FE, performance and emissions). As a result, a simulation tool was developed in MATLAB to generate an optimum gear shift pattern. Three different SUV/UV models were used as test vehicles in this study. Chassis dyno testing was conducted, and data was collected using the base and optimized gear shift patterns. Dyno test results with optimized gear shift pattern showed FE improvement of ~ 4 to 5% while retaining the NOx margin well above engineering targets.

Fuel efficiency is critical aspect for commercial vehicles as fuel is major part of operational costs. To complicate scenario further, fuel efficiency testing, unlike in passenger cars is more time consuming and laborious. Thus, to save on development cost and save time in actual testing, simulations plays crucial role. Typically, actual vehicle speed and gear usage is captured using reference vehicle in desired route and used it for simulation of target vehicle. Limitation to this approach is captured duty cycle is specific to powertrain and driver behavior of reference vehicle. Any change in powertrain or vehicle resistance or driver of target vehicle will alter duty cycle and hence duty cycle of reference vehicle is no more valid for simulation assessment. This paper demonstrates approach which uses combination of tools to address this challenge. Simulation approach proposed here have three parts.

The braking systems for modern day commercial vehicles with GVWs ranging above 7.5 metric tons use the typical s-cam drum brake system, where pressurized air is the actuating medium. The s-cam drum brake systems are popular today even after the advent and penetration of air disc brake systems, the main reasons being, cost-effectiveness, robustness, satisfactory performance and good component life. However, the brake systems of commercial vehicles (both M and N category) are frequently grappled with NVH issues particularly in the form of brake squeal noise (low frequency and high frequency). The noise with frequency more than 500 Hz can be generally defined as brake squeal. There has been a lot of work done and is being continued, at theoretical level, analytical level and experimental level to tackle with this issue.

One of the major discomforts while driving any medium to heavy commercial vehicle is brake judder. Brake judder can be defined as vibrations felt on steering wheel or brake pedal or cabin floor, when brakes are applied at certain speeds and pressures. The frequencies of this judder lie as high as 100 Hz to as low as 20 Hz. The brake judder is caused by a number of factors, which makes providing a universal solution difficult. Some of the causes are related to part fitment, part quality, material selection, manufacturing process, Design consideration, environmental factors, etc. This paper gives us a brief idea about resolution of judder problem in intermediate commercial vehicle by series of trials and this methodology can be applied in heavy commercial vehicles also. This paper gives reader an insight about step by step root cause analysis of brake judder on actual vehicle and an approach in resolving the judder problem.

S-cam air brake system is provided in almost all commercial vehicles having tonnage above 7.5-ton. In S-Cam brake system, drum to brake lining gap (henceforth referred to as ‘brake lining gap’ or simply ‘gap’ for convenience) range is an important factor which can impact braking behavior during brake application. Different OEMs (Original Equipment Manufacturers) define different brake lining gap ranges between S-cam brake lining and drum. This range depends majorly on the internal mechanism deployed in ASA (Auto Slack Adjuster). When these brake lining gaps start lowering i.e. when they fall in the range of 0 to 0.4 mm, or they become unstable (checked by feeler gauge at inspection window provided on dust cover of S-cam) then it starts impacting brake behavior in the subject vehicles.

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.

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.

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.

This paper reviews application of D-Cycle technology to compact tractor diesel engine for improving efficiency & power. The study considers design challenges that are presented for accommodating D-Cycle technology in engine. The paper also covers resolving those challenges with established technical solutions. The study focuses on modifying conventional compact 4-stroke diesel engine with the intention of keeping design changes to a minimum level for incorporating differential stroke technology. Designing of vertically splitting lightweight piston crown which can be smoothly engaged and separated from main piston body without any impact, stem rod which connects piston crown with rocker arm, split connecting rod and rocker arm which is actuated by extra actuating camshaft in addition of present valvetrain camshaft, are covered. Lubrication of additional actuating camshaft is done by extending existing oil galleries.

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).

The tractor usage is growing in the world due to derivative of rural economy and farming process. It needed wide range of implements based on the applications of the customer. The tractor plays a major role in Agricultural and Construction applications. In a tractor, hydraulic system is act as a heart of the vehicle which controls the draft and position of the implement. Hydraulic system consists of Powertrain assembly, 3-point linkage and DC sensing assembly. The design of hydraulic powertrain assembly is challenging because the loads acting on the system varies based on the type of implement, type of crop, stage of farming and soil conditions etc., Hydraulic powertrain assembly is designed based on standards like IS 12207-2019 which regulates the test methods for the system based on the lift capacity of the tractor. In this paper, virtual simulation has been established to optimize the design and perform the test correlation.

In an off-road vehicle, Vehicle Structure plays a major role in passenger safety, Aesthetics, Durability, through a validated construction of canopy structure. This structure is to maintain the shape of the vehicle and to support various loads acting on the vehicle. In present market a safe, Durable, Robust, Waterproof, Noise less, Light weight and cost-effective off-road vehicle will always be a delight for any customer. However, the current conventional way of Soft top vehicle structure use metal brackets and formed sheet parts to create a structure to retain the canopy shape in place. These conventional structures are often heavier and would have many demerits such as heavy weight, Corrosion, Risk of canopy tear due to metallic structure edges and inappropriate draining, water management. Considering this we replaced the heavy metal brackets in to blow molded plastic parts.

Agriculture tractor industry is highly competitive in the current market scenario with global majors competing in various markets. A tractor having an optimum design is of prime importance to keep the cost low while providing higher value to the customers. Technology advances in instrumentation methodology and data acquisition helps not only in providing the right inputs for the design of a component/system but also very much useful for design/system optimization. Front Axle Support of an agricultural tractor is one of the structural member which is connected to the Chassis which is called skid of the tractor to which the Front Axle is mounted through Pillow block (Plummer block) arrangement to facilitate axle oscillation about the tractor longitudinal center line. Front ballast weights are mounted on a bracket which is intern mounted to the front axle support to maintain the required front reaction in various agricultural operations.

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]

In any engine cooling system, de-aeration capability of the system plays a very critical role to avoid over heating of an engine. In general, with recovery bottle engine cooling system there is one vent hose from radiator pressure cap to the recovery bottle and coolant in the bottle is exposed to atmospheric pressure. From this vent hose air bubbles will move to recovery bottle from the engine and radiator when pressure in the system exceeds pressure cap setting. With this arrangement, de-aeration from the engine will happen when thermostat opens only and till that time air bubbles will be in the engine only and in this time there will be chance of overheating at some critical conditions because of air pockets in to the engine water jacket and the entrained air in the cooling circuit. Also, secondly 100 % initial filling cannot be achieved.

A hydraulic power train assembly of an agricultural tractor is meant to lift the heavy implements during field operations and transportation. As it is a crucial member of the tractor for its usage, so the power train assembly needs a properly designed lift arm, rocker arm assembly with better strength and stiffness. There are a standard like IS12224, IS4468 which regulates the test method for hydraulic power and lift capacity of tractor and the layout of hydraulic three point linkage. Computer aided engineering techniques followed by laboratory testing have been deployed in the earlier stages of the product design & development itself to deliver the first time right products to the customer. In this paper, a virtual simulation process has been established to design an agricultural tractor hydraulic lift arm to meet the above requirements. A Design Verification Plan (DVP) has been developed consisting of 3 load cases.

The maximum power produced by the Engine is utilized in overcoming the Aerodynamic resistance while the remaining has been used to overcome rolling and climbing resistance. Increasing emission and performance demands paves way for advanced technologies to improve fuel efficiency. One such way of increasing the fuel efficiency is to reduce the aerodynamic drag of the vehicle. Buses emerged as the common choice of transport for people in India. By improving the aerodynamic drag of the Buses, the diesel consumption of a vehicle can be reduced by nearly about 10% without any upgradation of the existing engine. Though 60 to 70 % of pressure loads act on the frontal surface area of the buses, the most common techniques of reducing the drag in buses includes streamlining of the surfaces, minimizing underbody losses, reduced frontal area, pressure difference between the front & rear area and minimizing of flow separation & wake regions.