A major challenge
Motor vehicles are used privately and commercially in just about any environment imaginable, and the stresses placed on material components can differ drastically depending on the environmental conditions. Driving or, more to the point here, braking hard or gently at +45 to –45 °C with zero to 100% humidity affects the brake components in drastically different ways, and the components need to be tested across those environmental spectra.
Ford has been in the industry for a very long time. And because they keep track of the weather conditions and locations where brake noise issues have been reported, they have a good idea where potential problems can creep in. These locales are not the environmentally placid and stable climates, but places where temperature and humidity can reach extremes or change rapidly and drastically. They are also not environments that are readily available or convenient for testing outside, and they’re difficult, if not near impossible for most test houses to simulate.
The MSC test facility is not one of those places. They test on a four-wheel chassis dynamometer in a climate-controlled (temperature and humidity) semi-anechoic test environment that can – in under 24 hours – transform a comfortable room temperature into a humid –15 °C, then with a series of hard stops jack up the brake temperature to 300 °C. And those tests can last up to two days – running non-stop. In these extreme environments, the measurement equipment used must not just to be able to survive the environ-mental changes, but be able to continue to provide accurate, reliable data throughout the process. To meet their needs, MSC uses a combination of a LINK dynamometer with Brüel & Kjær’s PULSE™ LabShop software and LAN-XI data acquisition module, simultaneously measuring all four wheels with five to six channels.
The process
The sequence of events that make up the testing process is often the same, whether it is a new brake system or an existing one. The vehicle to test is secured on the chassis dynamometer, then it is cycled across a range of speeds and brake conditions all under the various environmental conditions specified by Ford engineers. Ford also provides prototype and real-world data that is needed for correlation with chamber and environment simulation. From this point, it becomes an iterative process that requires close collaboration between MSC and Ford.
At any given time, MSC may have two to three vehicles in various stages of testing, running the gamut of its environmental and performance parameters. This cycle through extremes generates a mass of data that is then provided to Ford, who makes adjustments based on that data. The close working relationship is important because the vehicle might be back the next day with a new set of test parameters. And this cycle of exchange and test continues until that ideal quiet brake is achieved.
The product
In the end, everyone benefits when things work like they should. The end user enjoys coming safely to a nice quiet stop without ever having to think about what is going on between the brake pad and disc. And MSC and Ford benefit from the results of having satisfied their respective customers. The return on investment for accurate, quality data and the determination to maintain stringent testing standards is well worth the price.