Method of manufacturing a heat transfer small size tube
US5555622A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 1995 |
| Grant date | Sep 17, 1996 |
| Priority date | — |
| Expiry date | Feb 21, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49391
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of manufacturing a heat-transfer small size tube includes inserting a grooved plug in a metal tube having an outer diameter of 4.5 mm or more, performing a rotary or drawing process with respect to the outer surface of the metal tube while pulling the metal tube in the tube-axis direction, thereby continuously forming grooves, in the inner surface of the metal tube, in a spiral shape or in the tube-axis direction, each of the grooves having a ridge bottom width/bottom wall thickness ratio W.sub.2 /t defined as 0.2 to 1.5, a groove depth H defined as 0.15 to 0.30 mm, and a groove bottom width W.sub.1 defined as 0.15 to 0.50, and subjecting to diameter reduction process with a diameter reduction rate of 20 to 40% by performing at least one draw without plug process with respect to the metal tube to obtain a heat-transfer small size tube having a groove depth H defined by 0.15<H<0.25 mm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.