Tube expanding method for heat exchanger tubes and tube expanding apparatus for heat exchanger tubes
US8656749B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 9, 2010 |
| Grant date | Feb 25, 2014 |
| Priority date | — |
| Expiry date | Nov 4, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/53122
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
The present invention solves a problem with conventional tube expanding method for heat exchanger tubes that is susceptible, when carrying out tube expansion on U-shaped heat exchanger tubes that have a narrower diameter than in the past and forming flare portions in opening portions that have been subjected to tube expansion, to a buckling phenomenon at boundaries between straight portions and hairpin portions of the heat exchanger tubes or a vicinity thereof.Opening portions of U-shaped heat exchanger tubes 56 that pass through a fin layer 54 protrude from an upper end surface of the fin layer 54, hairpin portions 56b of the heat exchanger tubes 56 protrude from a lower end surface of the fin layer 54, and tube expanding billets 22 are inserted into each opening portion of the heat exchanger tubes 56 to carry out primary tube expansion that expands the diameter of each straight tube portion 56a of the heat exchanger tubes 56 to integrate the heat exchanger tubes 56 and fins 50. The primary tube expansion ends with each tube expanding billet 22 inserted into a boundary between the straight tube portion 56a and the hairpin portion 56b of a heat exchanger tube 56 or the vicinity the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.