7th July 2017 by Richard Yen
For today’s review of last year’s Enlighten Award, we’re taking a look at an entry from CSR, a leading public transport vehicle manufacturer based in China. As discussed a couple of weeks ago, bus manufacturers face similar pressures to passenger car manufactures in that improving fuel efficiency, and therefore reducing product weight, is a continued design challenge for engineering teams.
CSR’s TEG-6129-BEV is a 12 meter length of pure electric city bus, using self-developed powertrain and compatible lithium-ion battery. The low-floor city bus is a high end product for both the China and international markets.
To save weight from the vehicle during its development, CSR’s engineering teams utilized a variety of methods covering both material replacement and material reduction strategies. Lightweight Q700 high strength steel was used throughout the vehicle’s chassis and topology optimization methods were used to identify areas where material could be completely removed. Simulation technologies also led the design of the heavy battery set situated on the vehicle’s roof, while helping to solve engineering challenges such as the rigidity of the window profiles initially causing window panes to break.
The result was a bus that was lighter than many competitor vehicle constructed from aluminum. The vehicle’s body-in-white was 21% (500 kg) lighter than the baseline design, helping the TEG-6129-BEV to win a fuel-economy competition for serial hybrid EV buses in China during 2015.
Although the driver or passengers are unlikely to pay too much attention to the performance of a public transport vehicle, the transport authorities that purchase and run buses to serve their local population need to ensure that the vehicles are cost effective and minimize the impact to the environment. CSR is leading this effort in China by combining weight reduction strategies to great effect.