Abstract
This paper describes the design and implementation of a Detection System for Noisy Common Rail High Pressure Pumps during the “End of Line Test”. When components are missing, damaged or incorrectly machined, the pump can become noisy when running in particular conditions, showing at the same time the correct values for the typically controlled parameters. Therefore, to be able to detect such a noisy pump during the test, the production test bench is equipped with a microphone. In specific working conditions from a noise detection point of view (previously defined in a laboratory), the signals given by this sensor are analyzed and digitally treated with specific software in order to assess if the pump is noisy or not. This assessment is based on a comparison of the tested sample results with predefined thresholds, representative of a population of good pumps. Several signal analysis are carried out, at different stages of the test, to be able to detect various failure modes.
The system was implemented in an industrial environment, which includes several undesired sources of noise, as well as the presence of vapor and splashes of calibration oil. The study phase and its operation are described. This system is implemented and is currently working in the installations of Delphi Diesel System in Sant Cugat del Valles (Barcelona).
KEYWORDS: Noisy pump detection system, Common Rail Pumps, detection of mechanical defects, detection of unassembled components, acoustic noise.