Nano suppliers think smart

The hype surrounding the recently launched Tata Nano has focused primarily around the fact that it’s the world’s cheapest car, with the base model costing a meagre Rs 100,000. To meet this ambitious target, Tata Motors pushed its 100 Nano suppliers very hard to think innovatively and develop components that were not only low in cost and also low in weight. After all, both these factors were critical to the success of the entire project. These parts would also have to meet the country’s automotiv

Autocar Pro News DeskBy Autocar Pro News Desk calendar 01 Apr 2009 Views icon17584 Views Share - Share to Facebook Share to Twitter Share to LinkedIn Share to Whatsapp
Nano suppliers think smart
However, low cost did not mean low technology and many of the Nano's parts show a remarkable degree of sophistication and clever thinking in the way they have been designed. This will also help keep production costs down and reduce the car’s running costs over its lifetime. For instance, the large front bumpers help absorb impacts and also lower repair costs since they result in less damage to the steel body panels.

The Nano is the best example yet of ‘frugal engineering’, the mantra that global automakers are now trying to emulate. The vehicle is made up of 2,500 distinct parts that were designed from a clean sheet without any pre-conceived notions based on past experience. To lower costs, suppliers looked at solutions from the two-wheeler industry, which were then modified to suit the Nano. For example, the instrument cluster's centrally mounted position on the dashboard also makes it suitable for both left- and right-hand- drive versions. This saves Tata money, since it can use the same set-up for the export version as well. Sometimes, Tata used off-the-shelf parts if they met the performance specifications and helped lower costs.

Production feasibility and ease of manufacture were also important considerations, given the ambitious production target of one million units per annum that Tata eventually plans to make.

One smart way in which weight and cost was kept down was by using a thinner gauge of sheet metal, without compromising on safety. The use of aluminium for the Rico Auto-supplied engine block also helped reduce weight. As a result, the Nano tips the scales at just 600kg, compared to 665kg for its closest rival, the Maruti 800.

Body rigidity was another area of focus for the company and one important way in which it ensured this was by bonding the rear glass to the body. We take a closer look at some of the global and Indian suppliers to the Nano and their development efforts for its components.

In 2004, the Bosch Group started work on the Nano project. It understood that building a low-cost car would need a paradigm shift from the way modern cars are currently engineered. The process also put emphasis on reinventing the way cars are built, through innovative ideas. Since conventional Bosch systems are designed for high-end vehicles, providing solutions for a low-price vehicle was a challenging task for the German supplier. However, Bosch was confident that it could provide technical and innovative support in developing the Nano.

The first concept engine for the Nano was assembled in 2005 at Coimbatore in Tamil Nadu. It was fitted with standard components from Bosch's Petrol Engine Management System. Despite several technical constraints, the engineering team from Bosch and Tata did the first test firing of the engine. In the same year, at Tata's Engineering Research Centre, the first prototype vehicle was fabricated with the calibrated engine. The initial two-cylinder engine developed by Tata had a displacement of 586cc. Subsequently, they increased the engine capacity to 624cc to have optimised engine performance to cover other variants of the Nano that would be developed in the future for both the domestic and export markets.

Bosch developed a state-of-the-art petrol Engine Management System (EMS) for the Nano. The EMS consists of the electronic control unit, fuel injectors, sensors, ignition coil, tank vent valve and throttle body assembly. The software and the electronic control unit were developed to offer both optimised performance and a value-for-money price tag.

Bosch also developed a custom-made starter motor and alternator for the Nano. The new starter motor was conceived with a combination of optimised electrical layout and mechanical systems. It also matched the petrol engine’s speed and torque characteristics. Even though the electrical specs of the starter are new, the mechanical design is based on the compact direct starter system, which helps to reduce manufacturing costs.

Bosch also developed the braking system for the Nano. The system consists of a Tandem Master Cylinder (TMC) and four drum brakes. To keep costs low, the system was configured so that the conventional vacuum booster was not required. Instead of calipers on the front wheel, cost-effective drum brakes were used. All these components are fully localised in order to make them more cost effective. Bosch is also developing an anti-lock braking system for the Nano which would be fitted on the export version, the Nano Europa.

According to Bosch India president V K Viswanathan, “The Nano is a breakthrough product and Bosch is proud to be associated with it through our breakthrough technologies like fuel injection systems, brakes and electricals. This car will be a trendsetter in the new low-price vehicle segment in the near future.”

Packaging the starter motor and alternator into the limited space available was the biggest challenge for the company. The company designed a 60mm starter motor and compact alternator to fit into the space and uses new technology such as gear reduction for the starter and an internal fan for the alternator.

The tyre maker specially developed three different types of tyres for the Nano over a three-year period, keeping in mind that it was a rear-engined vehicle. A low rolling resistance design was utilised to lower the steering effort and improve fuel economy. The front tyre is smaller with a size of 135/70 while the rear is somewhat bigger at 155/65, both being mounted onto a 12-inch wheel developed by Wheels India. The spare tyre is of radial type to lower cost and weight. Another cost saver is that the wheels are fitted onto the car using three nuts instead of the usual four.

Tata Motors gave Cooper Foundry the responsibility for developing the engine cylinder liners. Cooper uses a highly specialised process for manufacturing these liners with the latest available technology, to ensure they fit an aluminum die cast engine block. Tata had the engine prototype developed in Germany and Cooper’s initial samples were sent there for approval and they received approval immediately. The entire development process took six weeks and Cooper says its liners give better heat transfer from the combustion chamber to the cooling water. The company has 10 years of experience in this field and claims that it is the only cylinder liner company in India capable of making hi-tech liners at competitive prices.

Tata AutoComp played a very significant role in the development of several components for the Nano. The company worked closely with Tata Motors from the inception of the project to design and engineer various components, keeping the cost, quality and performance parameters in mind, which required design and process optimisation.

Besides cost, the other challenge that the team faced was trying to lower the weight of each component, which resulted in the development of specially designed and engineered parts and systems. In most cases, it was developing various components for the first time. Since space was at a premium in the car, ensuring the components fit into a small space, without compromising on functionality, safety or aesthetics was a big challenge for TACO.

Since the Nano is rear-engined, the air flow to the cooling system was getting hampered and space was also a constraint given the smaller size of the Nano compared to conventional vehicles.

At the same time, the engine cooling solution was expected to be scalable, to meet the cooling needs of bigger versions of the Nano engine, which Tata planned to introduce on the export version. The team at Tata Toyo Radiator came up with many innovations to meet these challenges, including the styling of the rear doors to facilitate air intakes. Also, the fan motor, as well as the fan blades, were redesigned to increase efficiency, and air directors were developed to direct air more effectively onto the radiator core.

This was the first time in India that an engine induction system was made in plastic. This helped reduce the weight of the component substantially, and also improved its performance. Compared to the traditional aluminium manifold, this one delivers consistent air to the engine thereby ensuring superior engine performance.

The battery developed for the Nano is based on the company’s existing and superior Calcium-Calcium technology which ensures that there are no emissions that affect the health of the driver and passengers since the battery is fitted under the driver’s seat. These batteries also do not need top-up until 100,000km. Also, as the battery had to be light yet offer superior performance, special small-sized plates were designed with envelope-type separators to ensure that there are no short-circuits which are common in such batteries. Besides this, various safety features like individual cell ventilation and flame arrestors have been provided, making the batteries absolutely safe.

The Nano is designed with the engine at the rear but the battery in the front, which meant that the wiring harness and battery cable had to be developed in a way that they would work even in the upgraded versions of the Nano. The most crucial part in the entire circuit was the fuse box and Tata Yazaki designed a new fuse box based on ‘bus-bar’ technology with FF terminals. This helped in reducing 21 circuits without compromising on the functionality of the system.

The seating system had very challenging cost targets and the seats had to be light, offer good seating comfort, as well as good overall body support while meeting all the safety requirements. Also, the driver seat (as well as the front passenger seat in the higher models) had to recline as well as be able to move forward and backward. The rear seats had to be designed to be foldable to enhance rear cabin space. With such tough specifications, the design team at Tata Johnson Controls came up with innovative solutions that enhanced the aesthetics of the seats in a cost-effective manner. The front seats are based on a single-brace structure, instead of individual rails, a frame and the right amount of foam to ensure seating comfort.

The interior and exterior plastic parts include bumpers (in body colour for the higher models), instrument panel, air vents, cockpit (central instrument cluster assembly), door handles, door trims, pillar trims and various engine and powertrain plastic parts were supplied by the Interiors and Plastics Division of TACO.

These were innovatively designed and engineered to achieve weight reduction without compromise on functionality, aesthetics, regulatory and quality parameters. For instance, the air vents in the Nano needed a protective grille to avoid small objects (like coins) falling into the HVAC circuit. This was achieved by integrating a honeycomb grille into the bezel, thus reducing the total number of parts. The scooped-out recesses in the dashboard are meant to provide space to the occupants to keep small items while travelling.

The windshield washing system faced severe space and packaging challenges. After much development work, a relatively small system which had all the functionality that most cars offer was finalised. A sleek washer tank was developed, which is fitted in the front of the car under the hood. The company is the only supplier to the Nano for this system and can make as many as 350,000 units per annum.

Tata Ficosa undertook the entire design and development work on the shifter system. It has a cable-type gear shifter, as opposed to rod-type, which is a first for a small car in India. This helps in two ways — firstly it reduces the weight of the overall gear shifter system and secondly it makes shifting of gears much smoother. Once again, Tata Ficosa is the only supplier to the Nano and has a capacity to make 350,000 units per annum at full capacity.

The rearview mirror inside the Nano was redesigned to incorporate the cabin lighting system, thereby reducing the total number of components. The outer rearview mirrors in body colour were designed to enhance the car's styling. As with the other two components, Tata Ficosa is the single-source supplier for these parts and plans a 350,000 units per annum capacity.

Behr India was the designer of the Nano’s state-of-the-art climate control system. It supplies a full HVAC system, including the climate box, condenser, control panel, refrigeration and heating pipes. The biggest challenge was to create an effective air-conditioning system to accommodate the hot and humid climate in India at the most competitive price. For a small car, a powerful air-conditioner that doesn’t sap engine power is a crucial factor in the design process. All these challenges were to be fulfilled within just 11 months of development time against the normal 18~24-month period from concept to start of production. A special feature of Behr’s air-conditioning system is the flat tube evaporator with ‘BehrOxal’ coating which enhances the cooling performance and eliminates odour from the air-conditioning system.

The Nano's exhaust system is a highly engineered product designed keeping in mind constraints like limited space, since the system had to be packaged along with the engine and gearbox at the rear of the car. Thermal management was another challenge due to its proximity to the engine. This made material selection critical for parts like the heat shield, mat and type of steel used, while still meeting the tough cost targets. Emcon also had to deal with NVH issues since the engine is relatively small and the exhaust had limited volume in the muffler due to space limitations. Further cost containment was achieved through effective structural design for gas dynamics and maximum catalyst efficiency, hence reducing the requirement for expensive precious metals. The Nano can meet BS2, BS3 and BS4 norms with just a replacement of the monolithic brick that differs in the amount of precious metal it contains.

Gabriel India developed and supplies front struts and rear shock absorbers for the Nano. The challenges faced by Gabriel included developing these products in tandem with the development of the vehicle, and making them compatible with the vehicle structure and dynamics. A compact car with specifications of bigger cars was an interesting challenge for Gabriel’s engineering team, requiring the application of its past experience in the business. Production planning for the large volumes that the Nano would be made in was another challenge that required capacity balancing and investments by the company. Gabriel confirms that these products have high quality and durability and are comparable to its current range of products.

Mahle developed the oil, air and fuel filters for the Nano project. Special efforts were taken in the design of these parts. In order to keep weight down, particular attention was paid to the materials used. Advanced design tools like CAE and CFD were used to derive the optimum materials required and also minimise the pressure drops. An innovative and state-of-the-art design was incorporated in the oil filter where Mahle optimised the steel usage.

During the entire process, there was constant interaction with the entire Tata Nano development team. This project has been a tremendous learning experience for the company and it plans to use this knowledge to reduce the weight of all its filter products in the future, particularly those used on other Tata vehicles.

The company worked very closely with Tata Motors on the development of the driveshafts which transfer power from the gearbox to the rear wheels. According to the company, superior teamwork helped it to shorten development times. The new unit from GKN costs less, has reduced complexity and utilises common parts. These driveshafts, which are tailored to the specific requirement of the Nano and GKN, confirm that the company's European tech centre was used to support the development and localisation of this component in India.

Mahle claims the development process for the Nano camshaft was not dissimilar from its standard development process. They presented various alternatives and suggested a couple of changes in the specifications before locking on the final design. During this process, the company interacted closely with Tata’s ERC centre in Pune. The camshaft for the Nano is a rather more complex design as compared to standard camshafts; however Mahle still sees possibilities for the simplification of this part. The manufacturing process for this part is not very different from traditional parts. However, there are some specifications which are unusual, making the part more complex to produce and meet the metallurgical needs. The move out of Singur also impacted the company since it had already set up a facility, which is now lying unused. Currently, Mahle can produce 300,000 parts per year and also plans to have its camshaft on the export version of the Nano as well.

German supplier Continental developed the fuel supply unit for the Nano and was involved in the project from the concept stage. It worked with Tata to develop the specifications for the system, keeping in mind the cost targets and produces the unit in India. Costs were attacked throughout the value chain, from development to sourcing and then to production. Most of the development work was done in India and as well as in China. The weight targets were achieved by using alternate materials like plastics instead of metal. Also material costs were kept low through innovative design and sourcing from low-cost countries. Continental believes that this project has given its local product development, value engineering and manufacturing skills a big boost, which would benefit the company in the long run.

Delphi is supplying the instrument cluster and immobiliser, jointly developed with Tata, for the Nano. The company was involved from the concept stage, through to production intent and the design stage. The joint team developed electrical and mechanical interfaces for the Nano, as well as the scripting and formulating of critical algorithms and many other technical details. According to Delphi, a considerable amount of lateral thinking was done by its teams at Bangalore and in Michigan to rethink the cost structure. Cost-reduction ideas ranged from vehicle interface definitions to selection of materials for plastic enclosures and printed circuit boards. The instrument cluster was kept basic with just a speedometer, odometer and turn indicator signals. The fuel gauge was integrated with the display and the temperature indication was done through an LED indicator instead of a conventional gauge.

The major challenges that Delphi faced was keeping costs low while meeting unique electrical requirements like load dump protection and operation only through ignition.

The Nano project has indeed been a very challenging one for all the suppliers involved in it. They have come up with fresh ideas, using out-of-the-box thinking to design and develop components that are priced well below conventional parts. In doing so, they have gone through a steep learning curve and altered the manner in which they develop components. These are skills that will surely strenghten them in the years to come.
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