Chassioptimering : Ergonomisk optimering och monteringsförbättring av chassi för kylmoduler

Sammanfattning

Heat pumps are a growing product category within energy-efficient heating, and NIBE Energy Systems develops these products in industrial series production where assembly efficiency, ergonomics and repeatability are central factors. This work addresses the design basis for the cooling module chassis, a load-bearing and enclosing structure whose top cover in the reference design is attached to the side plates with a large number of screw joints. The existing assembly process requires simultaneous alignment of screw holes, compression of the sealing strip and manual fixation, which makes assembly time-consuming and physically demanding. The work followed a structured product development process with needs analysis in the production environment, idea generation, concept evaluation, CAD development, material selection and prototype manufacturing. Various fastening mechanisms were evaluated, including hinges, hooks, clamps, gluing and folded edges, before snap-fit was chosen as the principle. Snap-fit mechanisms are based on elastic deformation and enable self-positioning assembly without separate fasteners, which aligns with Design for Assembly principles and ongoing industry trends toward hybrid constructions of sheet metal and injection-moulded thermoplastic. The result is a new concept design with a two-part snap-fit locking mechanism in the corners that replaces most of the screw joints, simplifies the top cover geometry and maintains compatibility with existing components. The solution constitutes a design basis at concept level for further verification ahead of possible implementation at NIBE.