Pliassounov, S., "Perfection Targets and the Pathway to Seal Robustness Excellence for Automotive Brake Tube Joints," SAE Technical Paper 2014-01-2508, 2014, doi:10.4271/2014-01-2508.
The article discusses the common shortcomings of contemporary standardized automotive brake tubing connectors (tube joints) against the modern requirements. These shortcomings are originated in the inborn disadvantages of currently utilized cone-to-cone sealing surfaces' mating. During last decade modern production excellence mindset and lean manufacturing practice have developed additional requirements to the tube joints, with the focus on their assembly process. Correspondingly, at least 99.9% probability to assemble and seal each connector from the very first attempt at the designated assembly station is necessary to resolve the challenge. The article deliberates that 99.9% probability as the design target in pursuing connectors' excellence. The article also discusses the pathway to the connectors' design perfection via replacement of the existing cone-to-cone mating type between the sealing surfaces with a sphere-to-cone one. Operational windows' comparison provides the evidences of feasibility and superiority of the latter. Further opportunities in development of quick (snapping) connectors with superior sealing robustness through following that pathway have been also discussed.