Legislation governing emissions from automotive vehicles is forcing engine component manufacturers to explore new technologies to reduce emissions. Laser drilling offers a number of potential benefits which can help them achieve that aim including smaller injection holes or specially shaped holes.
Visible and UV lasers with nanosecond pulse durations, diffraction-limited beam quality and high pulse repetition rates have demonstrated an ability to machine a wide variety of materials with sub-micron precision and sub-micron-sized heat-affected zones. Manufacturing applications for these lasers include orifice drilling in fuel injection components.
Laser drilling of fuel injection components presents many technological challenges. The orifice dimensions and geometry must be precise and highly repeatable. Diesel fuel injectors present a particular challenge because the closed geometry of the injector tip means that it is very easy to damage the wall opposite the laser drilled hole. In this paper we will present results in drilling small precise holes, shaped holes and methods for preventing damage to the back wall in diesel nozzles. Holes as small as 20 microns diameter have been drilled. Holes with different shapes and tapers have also been drilled.