Definition av stötdämpares fyllnadsgrad

• Main Author: Vikman, Isak
• Format: Others
• Language: Swedish
• Published: Uppsala universitet, Institutionen för teknikvetenskaper 2012
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-176712

Shock absorber units play a key role in establishing the driving dynamics and performance of automobiles. Öhlins Racing has manufactured high-tech automotive shock absorbers for over 30 years. Öhlins Racing’s advanced technology has contributed to over 200 world championships in automobile racing. Öhlin’s manufacturing process has long utilized automated fluid filling equipment during the final shock absorber unit assembly stage. The filling process consists of vacuum pumping the shock absorber unit and subsequent transfer of fluid. Vacuum pumping is necessary to remove residual air from the shock absorber unit prior to initiating the liquid filling stage. The presence of undesirable gases drastically compromises the performance of a shock absorber. The filling degree, defined as the final ratio of air to oil, is determined by the specific filling protocol as well as the specific equipment utilized. The current investigation aims to develop a viable technique to accurately determine residual air content in shock absorber units. If the filling degree can be appropriately quantified for a specific manufacturing process, then the air/oil ratio may be quantitatively related to shock absorber performance. The utilized measurement method must be completely integrated into the manufacturing process to guarantee shock absorber performance specifications according to the manufacturer’s standards. By utilizing the measurement method developed in this work, the manufacturing process, manufacturing equipment and product specifications can all be tailored to provide improved filling conditions. The developed measurement method provides accurate quantification of the filling degree under a wide range of processing conditions. The method establishes the relative quantity of air in the shock absorber unit by performing in-situ compressibility tests. The fill ratio can be controlled and varied by manipulating the vacuum pressure exerted during the filling process. Performance tests, however, indicate no correlation between filling degree and unit performance.