The durability of Common-Rail component under high pulsating stresses is significantly limited by the stress concentrations that prevail at the cross-bores. Electro Chemical Machining (ECM) provides a mean for rounding off poorly accessible internal notches by controlled metal dissolution and hence preventing the build-up of excessive stress concentrations.
During electrochemical machining, metal dissolution is carried out by using an external power source, a salt solution and an electrode (tool), whereby, the work piece is the positive pole and the electrode the negative pole. Metal dissolution is carried out by the transfer of electrons in the outer electrical circuit and the simultaneous dissolution of positively-charged metal ions at the work piece. Localized metal dissolution for rounding off contours and the elimination of burrs is enabled by geometrically-controlled polarization between the work piece and the electrode (tool) and through the chemically and thermally, stable conditions of the process.
Today, numerous high-pressure components, ranging from the smallest up to 3 m long Common-Rails, are processed by the FUCHS DIESEL COMPONENTS PRODUCTION utilizing in house developed ECM equipment. The manufacturing process has been established and verified based on data collected over more than 20 years of experience. The inspection of poorly accessible edges is carried out visually using endoscopic methods.