A supplier's test-shop-on-wheels enables engineers to test and install properly fitted wiper blades in a few hours, saving the time and cost associated with the conventional weeks-long approach to testing.
The start point for Federal-Mogul's Rapid On-Site Prototyping—a process for testing and modifying its wiper blade prototypes via customized software and equipment—is a car parked inside a wind tunnel.
"With Federal-Mogul's Rapid On-Site Prototyping, we conduct a test, learn what needs to be improved, and then directly modify the design of the wiper blade's flexor. We manufacture the prototype, install it on the car, and run the next test until we achieve the right compromise and the expected result. This test session typically last 4 h for a passenger vehicle," said Rene Masson, Global Director-Engineering, Research and Development for Federal-Mogul.
For the past three years, several automakers in Europe and North America have bypassed the standard way of conducting wiper blade fittings for Federal-Mogul's process. A traditional testing process typically spans several weeks, sometimes several months.
"To our knowledge, no other wiper blade supplier has a system with the ability to speed up the definition of a flat blade for a car as well as save money in terms of wind tunnel costs and a test engineer's time," said Masson. After the first test is run, "the test engineer reviews the test results and provides direction as to how the flexor shaping should be modified to improve the wipe," said Masson.
Federal-Mogul's testing procedure elicits a wiper blade that provides a snug and clean windshield sweep. "Before the session, wipe defects could appear at 160 or 170 km/h. After the test session, we can frequently achieve a good wipe performance at 210 km/h—or even above—with the defined flexor shape," Masson said.
The Rapid On-Site Prototyping (ROP) process has been refined in recent months. "We improved the system by implementing the following: After each flexor is manufactured, we use a visual camera to obtain an accurate dim check of the flexor and input that information into our database. So even three or six months later, we know what the exact shape of the flexor was," said Masson.
Knowing the exact shape of the flexor is essential information. "Before the recent refinement, we knew the flexor was in the appropriate tolerance range, but now we also know that the shaping of the flexor is 100% accurate based on the prototype test done on the car while undergoing a high-speed wind tunnel test," Masson explained. More refinements to the ROP process are under way.
"We are working on a project to measure the curvature—the shaping of the rubber edge—after the assembly of the blade," said Masson. "We are targeting to achieve that in the next two months. This will allow us to also take into account the interaction of the different components and thus further improve our blade definition."
Federal-Mogul sells to automakers approximately 22 million wiper blades each year, including a high-performance flat wiper blade that uses a unique bayonet connection. The ROP process is unlikely to be used for commercial vehicle applications as those "vehicles do not have to achieve such high wiper speeds, but it would definitely be applicable—and make much sense—for the motorsports segment," said Masson.