Method for making heat pipes

摘要

A metalworking tool is capable of making internally grooved and externally finned heat exchanger coils from ordinary tubes in a single operation in which the tubes are expanded into bonding mechanical contact with external fins at the same time that grooves are formed in the inner surfaces of the tubes. The process is performed by a tool head having both expanding and groove forming tools mounted thereon. The expanding tool preferably comprises a hardened expansion ball which mechanically expands the tube with or without hydraulic or pneumatic assist. The groove forming tool may comprise a cutting point which scribes the tube, a roller which forges a groove, or any other suitable scribing or forging device. The groove forming tool may rotate or oscillate to produce nonlinear grooves and may form grooves during the in-going and/or out-going strokes of the tool.