2013 Pm technology review
PM part suppliers are not immune from the increasingly tight tolerances being demanded by customers. In the case of precision ground PM parts, such as variable valve timing (VVT) components and gerotors, deburring/edge break specifications are also tightening. Because these parts are often ground to tolerances of a few microns, the added challenge is removing the sharp ground edges in a controlled manner, with minimal overall material removal. In many cases, in-line deburring using abrasive filament brushes represents the only viable method to achieve these objectives. Abrasive filament brushes employ nylon filaments that have been co-extruded with abrasive grains. In application, these filaments act like flexible files, expending most of their energy as they strike a sharp edge. Providing a measured, and consistent, edge break on each ground edge of a part is often only possible by presenting the part to abrasive filament brushes rotating in a planetary motion. Planetary head brush deburring systems employ magnetic conveyors to “fixture” the parts as they are being brushed. Use of a magnetic conveyor provides for a very flexible process that can accept a wide range of parts. Precise alignment of the brush face to the part surface is essential in order to meet quality specifications and maximize brush life.
Important future trends for the decade:
Corporate average fuel economy (CAFE) standards are forcing automakers to adopt new powertrain technologies. Variable valve timing (VVT) technology offers the benefit of higher power and increased fuel economy. Automakers are adding this technology to more vehicles and precisely ground PM components are at the heart of this. Another technology involving PM parts contributing to greater fuel economy is “stop/start”. Here, an engine shuts off when the brake is applied and the vehicle is stopped for more than a few seconds. Maintaining automatic transmission fluid pressure is necessary during this time, and a pump, employing ground PM gerotors, is often used. “Stop/start” technology is forecast to become widespread on vehicles in the future. Adoption of both of these technologies has the potential to dramatically increase demand for their associated PM parts. Efficient and effective deburring can be accomplished via automated systems employing planetary heads driving abrasive filament brushes.