Hydrauliskt säkerhetsblock : Hur ett ventilblock konstrueras upp till PLe enligt ISO 13849

Sammanfattning: This work has been done in collaboration with Camatec Industriteknik AB, who wanted to investigate how to manufacture hydraulic valve blocks, safety blocks, according to ISO 13849 and the PL scale. As this standard is being increasingly implemented in everything from industrial machines to mobile hydraulics, it is desired to conduct an early investigation on the possibilities of producing valve blocks in compliance with this standard. The work lasted for a period of 10 weeks and was carried out at LiU (Linköpings Universitet) and Camatec's office in Karlstad. It started by determening whether a design could comply with the PL scale from the standard and if so, how. A requirement specification was compiled based on the requirements that concerned the block itself. An existing concept proposal was iterated and formed the basis for a calculation model. With a preliminary stress-value, several materials were found based on recommendations and databases that met the set requirements. The materials were weighted in a weighting matrix and two final materials was determined. A final concept was made including a fatigue analysis with the selected materials. When material selection, construction and calculation were completed, a drawing was created that was used for manufacturing quotes. The result was a construction with two different material proposals. One version is designed for an MTTFD value of 150 years and the other for an infinite MTTFD. Depending on other components of a system, these safety blocks are compatible up to PLe, the highest level in the scale. When implementing this safety block, other parts of the system must meet the set requirements, it is recommended that the development of ISO 13849 is carefully followed in the future.