GB2040763A - Tube straightening by rolls - Google Patents
Tube straightening by rolls Download PDFInfo
- Publication number
- GB2040763A GB2040763A GB8002239A GB8002239A GB2040763A GB 2040763 A GB2040763 A GB 2040763A GB 8002239 A GB8002239 A GB 8002239A GB 8002239 A GB8002239 A GB 8002239A GB 2040763 A GB2040763 A GB 2040763A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rolls
- roll
- concave
- pairs
- convex
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005096 rolling process Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D3/00—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts
- B21D3/02—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts by rollers
- B21D3/04—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts by rollers arranged on axes skew to the path of the work
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Bending Of Plates, Rods, And Pipes (AREA)
- Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
- Straightening Metal Sheet-Like Bodies (AREA)
Abstract
Apparatus for straightening tubes comprises three pairs of rolls, of which the central pair has one convex roll (5) and one concave roll (4) while the outer pairs have only concave rolls (2,3). The bulge length of the convex roll (5) and the concave roll (4) is greater than that of the rolls of the outer pairs. <IMAGE>
Description
SPECIFICATION
The straightening of tubes
The invention relates to a method and apparatus for straightening tubes using three pairs of rolls.
An apparatus for straightening tubes is known from published German Patent Appliction No. 25 02 651, in which the top roll is of concave and the bottom roll of convex construction in the central pair of rolls. In the region of the top roll, guide rollers are arranges in front of and behind the bottom roll in order to prevent the stock from escaping. For design considerations, however, a certain interval always exists between the guide rollers and the central pair of rolls, which has disadvantageous effects upon the possibility of straightening the tube ends.
It is also disadvantageous that the required guide means, if they are constructed as straight edges, may cause damage to the tube surface and are also subject to heavy wear. Tube surface faults can likewise be caused by the bottom rolls due to their short bulge length.
According to the present invention, apparatus for straightening tubes has three substantially aligned pairs of rolls, of which each outer pair comprises rolls with concave rolling surfaces, the central pair comprising one roll with a concave rolling surface and one with a convex rolling surface, and wherein the bulge length of the convex roll and the concave roll of the central pair is greater than that of the rolls of the two outer pairs.
In a method of straightening tubes according to the invention using three pairs of rolls, both an additional flexural moment and an oval deformation are superimposed upon the flexural moment applied to the stock in the region of maximum flexural moment.
The invention makes it possible to straighten tubes having a thicknessidiameter ratio > 0.10 and short bent ends, whilst the cold work-hardening which occurs does not inadmissibly modify the required technological characteristics of the stock.
The invention may also be applied for thin-walled stock, e.g., with a thickness/diameter ratio of 0.025.
Further, the invention renders the hitherto customary guide straight edges or guide rollers superfluous, so that damage to the stock can no longer occur.
An embodiment of the invention will now be described by way of examples and with reference to the accompanying schematic drawing which shows an arrangement of rolls with a moment diagram therebeneath.
In the drawing tube stock 1 is gripped by the two outer concave pairs of rolls. In the centre between these two pairs of rolls, the pair of rolls comprising one concave roll 4 and one convex roll 5 is arranged.
A moment diagram, from which the superimposition can be seen, is illustrated in order to characterise the flexural moments occuring according to the invention.
Due to the arrangement of the concave roll below the convex roll it was possible to dispense with the guide rollers, so that it is not only possible to avoid damage to the tube, but also particularly and for the first time to straighten the short ends, which was impossible in the prior art due to the design conditions.
Claims (7)
1. Apparatus for straightening tubes having three substantially aligned pairs of rolls, of which each outer pair comprises rolls with concave rolling surfaces, the central pair comprising one roll with a concave rolling surface and one with a convex rolling surface, and wherein the bulge length of the convex roll and the concave roll of the central pair is greater than that of the rolls of the two outer pairs.
2. Apparatus according to Claim 1, wherein in the central pair, the convex roll is arranged above the concave roll.
3. Apparatus according to Claim 1 or Claim 2, wherein the spacing between the roll pairs is variable.
4. Apparatus for straightening tubes substantially as described with reference to and as illustrated by the accompanying drawing.
5. A method of straightening tubes in apparatus having three pairs of rolls, of which the outer pairs comprise rolls wich concave rolling surfaces, the central pair comprising one roll with a concave rolling surface and one with a convex rolling surface, wherein, both an additional flexural moment and an oval deformation are superimposed upon the flexural moment applied to the stock in the region of maximum flexural moment.
6. A method according to Claim 5; wherein tube stock is subjected to at least five plastic flexures and counterfiexures in the region of superimposition.
7. A method of straightening tubes substantially as described herein with reference to and as illustrated by the accompanying drawing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2902827A DE2902827C2 (en) | 1979-01-23 | 1979-01-23 | Cross-roll straightening machine for pipes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2040763A true GB2040763A (en) | 1980-09-03 |
| GB2040763B GB2040763B (en) | 1983-03-09 |
Family
ID=6061377
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8002239A Expired GB2040763B (en) | 1979-01-23 | 1980-03-23 | Tube straightening by rolls |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS55100824A (en) |
| DE (1) | DE2902827C2 (en) |
| FR (1) | FR2447239A1 (en) |
| GB (1) | GB2040763B (en) |
| IT (1) | IT1130892B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4763504A (en) * | 1981-07-06 | 1988-08-16 | Nilsson Einar W | Straightening machines and methods |
| CN112718928A (en) * | 2020-12-10 | 2021-04-30 | 中国重型机械研究院股份公司 | Round material straightening device and straightening method thereof |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5744624U (en) * | 1980-08-21 | 1982-03-11 | ||
| DE3441537A1 (en) * | 1984-11-14 | 1986-05-15 | Th. Kieserling & Albrecht Gmbh & Co, 5650 Solingen | SLOPE ROLLER LEVELING MACHINE WITH MORE THAN 2 ROLLERS |
| CN104971966B (en) * | 2014-04-05 | 2017-01-25 | 薄占川 | Combined curve multi-inclination-roller steel pipe straightener |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR850276A (en) * | 1939-12-12 | |||
| GB598757A (en) * | 1945-09-08 | 1948-02-25 | Bigwood Joshua & Son Ltd | Improvements in machines for straightening tubes or rods |
| FR741308A (en) * | ||||
| FR2071404A5 (en) * | 1969-12-29 | 1971-09-17 | Brochut Max | Discharging internal tension - from round bars |
| FR2258912B1 (en) * | 1974-01-25 | 1979-01-05 | Vallourec | |
| FR2374103A1 (en) * | 1976-12-14 | 1978-07-13 | Semenenko Jury | Skewed roll straightening machine - having complex contoured rolls adapted to treat varying diameter workpiece in single pass |
-
1979
- 1979-01-23 DE DE2902827A patent/DE2902827C2/en not_active Expired
-
1980
- 1980-01-23 JP JP673480A patent/JPS55100824A/en active Pending
- 1980-01-23 IT IT19383/80A patent/IT1130892B/en active
- 1980-01-23 FR FR8001386A patent/FR2447239A1/en active Granted
- 1980-03-23 GB GB8002239A patent/GB2040763B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4763504A (en) * | 1981-07-06 | 1988-08-16 | Nilsson Einar W | Straightening machines and methods |
| CN112718928A (en) * | 2020-12-10 | 2021-04-30 | 中国重型机械研究院股份公司 | Round material straightening device and straightening method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55100824A (en) | 1980-08-01 |
| DE2902827C2 (en) | 1984-05-10 |
| IT1130892B (en) | 1986-06-18 |
| GB2040763B (en) | 1983-03-09 |
| FR2447239B1 (en) | 1983-12-09 |
| FR2447239A1 (en) | 1980-08-22 |
| IT8019383A0 (en) | 1980-01-23 |
| DE2902827A1 (en) | 1980-07-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |