Grinding Out Better Fuel Injector Nozzles
UVA U80 Bore-Grinding Test Center
The need to achieve better fuel economy is driving the requirement of increasingly tighter tolerances for fuel injector bores. Meister set out to test the viability of the new 3D Abrasive Technology for improving bore tolerances without sacrificing other important variables such as surface finish, cycle time, or wheel life. Trials were conducted on a fully instrumented UVA U80 bore grinding machine using a benchmark standard Vit-CBN wheel and then with a 3D Vit-CBN wheel. The CBN type, grit size, concentration, wheel hardness, and the shank were all held constant. Identical process conditions, including grind and dressing parameters, were also held constant.
Results shown in the table below speak for themselves. There was a 7x improvement in taper and a 7x improvement in cylindricity with virtually no change in the required surface finish or cycle time. In this application, 3D Abrasives significantly out-performed the heretofore best available abrasives technology without sacrificing anything.
No attempts were made in this study to adjust grinding parameters to achieve a different balance of results, for example sacrificing some of the taper improvements to obtain faster cycles and greater productivity. These considerations, of course, would be part of a normal grinding process development protocol.
Meister engineers attribute the success of the 3D product in this application to the extreme openness of the wheel’s pores, which carry coolant, flush away swarf, reduce grinding forces, and limit the potential for burning. There are many other grinding applications in which 3D Abrasives Technology is under consideration for extending grinding performance beyond the limitations of current best practice solutions.
