Shaving weight to compensate for BSIV hardware
To enhance the performance and comply with BSIV emission norms, DICV, to fit an exhaust gas aftertreatment (SCR), resorted to light weighting. The engineering team went through the entire truck; analysed every nut and bolt to achieve weight reduction of upto 400 kg. The team turned to value analysis. Functions of different parts were analysed. Material analysis was carried out. The exercise, expected to shave up to 300 kgs on lighter trucks, led the team to choose materials that would balance cost and weight. Material and design changes played a crucial role, and also the non-load bearing members. The grade of material was improved to facilitate a reduction in thickness, and in-turn weight. Without sacrificing performance or reliability, weight reduction was achieved through the use of superior grade material. In many application areas, the use of ‘Domex 650’ high strength steel was resorted to. This steel grade is used by many body builders to build containers in North India, and leads to substantial weight saving. The Domex cold forming steel the company is claimed to have used, is thermomechanically rolled. Its heating, rolling and cooling processes are carefully controlled.
To increase fuel efficiency, DICV compartmentalised the function of engine and the after-treatment system. SCR was chosen since it reduces the engine effort to meet tighter emission norms. With the chemical process limited to the after-treatment system, the SCR is often looked upon as an advanced active emissions control technology system that injects AdBlue into the exhaust gas stream while the engine is operating. Reducing (Nitrogen Oxide) NOx emission primarily, the SCR helps to achieve better fuel efficiency by putting hardly any burden on the engine. Engine performance is thus not compromised. Nitrogen Oxide (NOx) flows into the SCR system for reduction reactions to take place in an oxidising atmosphere. SCR reduces the level of NOx using ammonia as a reducing agent within a catalyst system. For the chemical reaction Diesel Exhaust Fluid (DEF) is used as a reducing agent that reacts with NOx to convert the pollutants into nitrogen, water and less amount of CO2. DEF also enables the engine to use less EGR and higher oxygen levels for better combustion. With the use of SCR, NOx can be reduced by up to 90 per cent. The system, it is clear, seeks a balance between fuel efficiency and emissions.
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