IAA report: Plastics replace metal in timing case cover

During the IAA international automotive exhibition this year in Frankfurt, automotive systems supplier Mann+ Hummel is displaying a number of recent developments including an injection molded plastic timing case cover for a car's engine. The molded polyamide part is to replace significantly heavier metal ones.

Weight savings are one of the reasons for the material switch, says Mann+Hummel (Ludwigsburg, Germany); transitioning to plastics also means additional components such as the engine bearing, oil filter and oil cooler can be integrated into a single system.

Throughout the exhibition, carmakers and their suppliers are touting vehicles powered by alternative energy, new battery concepts and other alternatives to gasoline. But light weighting of parts remains a huge component of the automobile industry's strategy to meet stricter fuel consumption requirements. The math is simple; the lower the vehicle weight, the lower the fuel consumption and carbon dioxide emissions.

That simple equation continues to add up to new opportunities for plastics in automotive applications, both in the interior as well as around the engine. An example of the latter is the new timing case cover from Mann+Hummel. The plastic version is 1.5 - 2 kilograms (3-4.5 lbs) less heavy than the established aluminum versions.

Depending on design, the plastic cover also can integrate additional engine functions and components into the housing cover including the oil filter module, engine bearing, water pump and crankcase ventilation.

For the timing cover on display during the IAA (Sep. 15-25), the Tier supplier is exhibiting a timing cover that integrates the oil filter and oil-water heat exchanger. Besides the saving in weight, the improved oil and water circulation also results in a lower pressure loss in the oil circuit, says Mann+Hummel.

As a result, a smaller oil pump can be used or the power consumption of the regular oil pump can be reduced, leading to a greater reduction in carbon dioxide emissions. A further reduction is produced by the integration of an oil pressure switch in the clean oil drain; this switch serves as a signal transmitter for the switchable piston cooling system. An electronically shifted valve in the water circuit, which turns the oil cooler on or off as needed via the engine management system in certain operating modes, reduces CO2 emissions even further.

In addition to weight savings, better parts integration and lower system costs, Mann+Hummel says the newly designed timing case covers also can help improve acoustic damping.