Claims
- 1. A method for the manufacture of a fin tube, comprising the steps of:
- a) forming helical extending fins on the outer surface of a smooth-surfaced tube by moving the fin material from the tube wall radially outwardly by means of a rolling operation;
- b) using, during the rolling operation, at least two rolling tools resting on the tube, which rolling tools consist of several side-by-side lying rolling disks with different diameters, which can be radially pressed into the tube wall and the shafts of which are arranged during the fin creation under a predetermined lead angle .alpha. with respect to the tube axis, which angle corresponds with the desired number of fin run starts n;
- c) supporting the smooth-surfaced tube on a rolling mandrel lying therein;
- d) rotating and/or axially advancing the fin tube by the rolling forces corresponding with the fins being created, with the fins being formed to an increasing height out of the otherwise nondeformed smooth-surfaced tube; and
- e) selecting a number of fin run starts n to be n>N, wherein N is the existing number of the rolling tools so that at least one of the rolling tools produces more than one fin run start.
- 2. The method according to claim 1, wherein each rolling tool produces two fin run starts.
- 3. The method according to claim 1, wherein each rolling tool produces three fin run starts.
- 4. The method according to claim 1, wherein each rolling tool produces four fin run starts.
- 5. The method according to claim 1, wherein the fin tips are deformed in at least one step by radial forces.
- 6. The method according to claim 1, wherein notches are pressed into the fin tips by at least one notch disk.
- 7. The method according to claim 6, wherein the finned tips are split in direction of the fins and are bent by axial forces and are deformed by radial forces.
- 8. The method according to claim 1, wherein the smooth-surfaced tube is supported by a profiled rolling mandrel.
- 9. The method according to claim 1, wherein after the forming of the fins the groove between the fins is continuously pressed inwardly by radial forces, with no support by an inner mandrel taking place in this area so that tube wall material for forming of corrugations are shifted to the inside of the tube.
- 10. The method according to claim 9, wherein not all rolling tools, which are being used, have a corrugating disk.
- 11. The method according to claim 6, wherein the finned tips are split in direction of the fins.
- 12. The method according to claim 6, wherein the finned tips are bent by axial forces.
- 13. The method according to claim 6, wherein the finned tips are deformed by radial forces.
- 14. The method according to claim 1, wherein after the forming of the fins the groove between the fins is only at points pressed inwardly by radial forces, with no support by an inner mandrel taking place in this area so that tube wall material for forming of corrugations are shifted to the inside of the tube.
- 15. The method according to claim 14, wherein not all rolling tools, which are being used, have a corrugating disk.
Priority Claims (1)
Number |
Date |
Country |
Kind |
44 20 756.5 |
Jun 1994 |
DEX |
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Parent Case Info
This is a division of Ser. No. 08/465,758, filed Jun. 6, 1995.
US Referenced Citations (3)
Divisions (1)
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Number |
Date |
Country |
Parent |
465758 |
Jun 1995 |
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