EP0703014B1 - Procédé pour laminer des blocs creux dans un laminoir de type Assel - Google Patents

Procédé pour laminer des blocs creux dans un laminoir de type Assel Download PDF

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Publication number
EP0703014B1
EP0703014B1 EP95250149A EP95250149A EP0703014B1 EP 0703014 B1 EP0703014 B1 EP 0703014B1 EP 95250149 A EP95250149 A EP 95250149A EP 95250149 A EP95250149 A EP 95250149A EP 0703014 B1 EP0703014 B1 EP 0703014B1
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EP
European Patent Office
Prior art keywords
rolls
hollow shape
assel
rolling mill
diameter
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.)
Expired - Lifetime
Application number
EP95250149A
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German (de)
English (en)
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EP0703014A1 (fr
Inventor
Jürgen Dr.-Ing. Pietsch
Ingo Baade
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vodafone GmbH
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Mannesmann AG
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Publication date
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Publication of EP0703014A1 publication Critical patent/EP0703014A1/fr
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B19/00—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work
    • B21B19/12—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work the axes of the rollers being arranged essentially parallel to the axis of the work
    • B21B19/16—Rolling tubes without additional rollers arranged inside the tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B19/00—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work
    • B21B19/02—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work the axes of the rollers being arranged essentially diagonally to the axis of the work, e.g. "cross" tube-rolling ; Diescher mills, Stiefel disc piercers or Stiefel rotary piercers
    • B21B19/06—Rolling hollow basic material, e.g. Assel mills
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B23/00—Tube-rolling not restricted to methods provided for in only one of groups B21B17/00, B21B19/00, B21B21/00, e.g. combined processes planetary tube rolling, auxiliary arrangements, e.g. lubricating, special tube blanks, continuous casting combined with tube rolling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
    • B21B37/78—Control of tube rolling

Definitions

  • the invention relates to a method for reducing the outer diameter and the wall thickness by rolling a cylindrical hollow block which is inserted with its front part into an Assel rolling mill, wherein a device for reducing the diameter and / or the wall thickness of the rear end part of the is provided on a mandrel bar threaded hollow block, the pre-reduction rollers reducing the end of the hollow block can be set against the hollow block and can be guided away therefrom.
  • the reason for the triangulation lies in the tendency to widen in the rolling mill and is process-related. If the longitudinal tensile stress in the billet drops towards the end of the rolled stock because there is no longer enough material to be formed in the inlet cone of the Assel mill, the tendency to increase the proportion of tangential forming increases. This means that the radial deformation causes more tangential and less longitudinal deformation. This in turn causes an increase in diameter. If the tangential exit speed between the rollers and the mandrel becomes greater than the pull-in speed of the following roller, there is a material jam in the free spaces between the three rollers, which can block the longitudinal feed movement. A method of the type mentioned at the outset is known from WO 90/00449.
  • a pre-reduction device on the inlet side of the Assel mill, which consists of three or four adjustable pre-reduction rollers, the axes of which have a slight inclination to the rolling stock axis or stand axis of the Assel mill.
  • This angle of inclination can be adjustable or fixed and is based on the average feed angle of the wood mill.
  • the object of the invention is to optimize the speed and forming conditions and thus the effect of the pre-reduction in a method of the type mentioned at the outset. This object is achieved by the characterizing features in claim 1.
  • the present invention has recognized that it is not sufficient to simply reduce the ends of the hollow blocks arbitrarily before entering the wood mill, rather certain speed and forming conditions must be observed if the pre-reduction does not lead to a deterioration of the hollow block ends or the intended effect should even be abolished. It was also found that the conditions depend on which pipe diameter and wall thickness are rolled in the Assel mill.
  • the rear end of the hollow block should be as perpendicular as possible to the longitudinal axis, it is best to use sawn blocks. Oblique hollow block ends and large ones Differences in wall thickness at the end also lead to partial (one-sided) triangulation.
  • Advantageous refinements of the invention result from the subclaims.
  • the diameter of the tangential circle between the rollers of the pre-reduction device is of particular importance in the employed state.
  • Favorable results can be expected if the guide values specified in claim 2 are observed.
  • a hollow block end is created if the specified criteria are met, which ends after a conical transition with a cylindrical reduced hollow trestle wall. In the extreme case, the length of the cylindrical part of the reduced hollow block end can be zero.
  • feed angles are specified for the rolls of the wood mill, which likewise reduce the widening in conjunction with the features of the invention explained above. It was recognized that in addition to the reduction in wall thickness, the feed angle also influences the widening, this angle must be at least sufficiently small, at least for the rolling out of the rear hollow block end, so that not too much material enters the roll gap per revolution. Claim 3 indicates a preferred feed angle ⁇ between 3.5 and 6 degrees, in which the invention can be carried out particularly cheaply. If, however, the feed angle is too small, the axial exit speed is low, and on the other hand the widening that occurs as a result makes it more difficult to detach the cap from the mandrel bar.
  • the circumferential roller speed is between 1.5 and 6 m / s, preferably between 4.0 and 4.5 m / s. adjust.
  • Claim 5 specifies dimensional ranges for the length of the smoothing parts based on different hollow block diameters.
  • the run-out angle related to the smoothing part of the woodlice should be 4 to 6 degrees. It is advantageous if the transition between the smoothing part and the outlet part is rounded off by a radius, that is to say a sharp edge is avoided. It is also possible to make the entire outlet part curved, ie to completely replace the conical or linear part by a rounded part.
  • the spreading angle ⁇ which for example is 3 degrees in conventional divergent wood mills, is slightly opened, i. H. is increased by 0.3 to 0.7 degrees to then 3.3 to 3.7 degrees.
  • rollers are moved into a position near the surface of the hollow block before the rollers of the pre-reduction device are closed.
  • Corresponding information is given in claim 7.
  • Advancing the rollers of the pre-reduction device has the advantage that the rollers represent an additional guide for the hollow block during rolling in the wood mill and greater security is achieved in order to achieve the necessary reduced length.
  • the schematic illustration shows two of three woodlice rolls of a woodlice mill, designated 1, which process the hollow block 2 to reduce the diameter and wall thickness.
  • the pre-reduction device the three rollers of which are denoted by 3, is connected upstream of the wood rollers 1.
  • the dome 4 can be seen in the interior of the hollow block 2.
  • the roller of the woodlouse mill consists of the inlet part 5, the working part (shoulder) 6, the smoothing part 7 and the outlet or rounding part 13.
  • the spreading angle of the rollers 1 is denoted by ⁇ .
  • the surfaces of the three rollers 3 of the pre-reduction device facing the roller axis are touched in their illustrated working position by a tangential circle which has the diameter D NEL .
  • the hollow block 2 is reduced to an outer diameter, which is indicated by dashed lines at 8.
  • a conical transition area arises from the outer diameter of the hollow block D H to the diameter D NEL corresponding to the tangential circle , such as shown in sections below the rollers 3.
  • the conical transition area is designated 11 there.
  • the total length between the start of the conical region 11 following the hollow block diameter D H to the end of the hollow block 12 is L NEL .
  • the basic thickness shows the wall thickness S H and the tangential circle in the "high point" of the woodlice and is denoted by D HP .
  • the outside diameter of the billet leaving the Assel mill is designated D L
  • the wall thickness of the billet is designated S L
  • the diameter of the dome bar is shown at D M.
  • a pre-reduction device for performing the method according to the invention works hydraulically.
  • the maximum pressure force of the rollers of the pre-reduction device is predetermined for a given hydraulic cylinder and choice of pressure, the hydraulic pressure is generally constant.
  • the closing speed can be set by means of a valve via the flow rate per unit of time, working at low speeds.
  • the start of the closing process of the rollers of the pre-reduction device can be triggered by photocells, the closing time must be chosen depending on the hollow block diameter. It is also conceivable to determine the axial speed in the inlet with two sensors and a microprocessor using a time measurement for a defined measuring section. The start of the closing process can thus be adapted to the speed.
  • the opening of the rollers of the pre-reduction device can also be triggered by a photo cell.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Metal Rolling (AREA)
  • Control Of Metal Rolling (AREA)

Claims (7)

  1. Procédé pour réduire le diamètre externe et l'épaisseur de paroi par laminage d'un bloc creux cylindrique, qui est introduit, par sa partie avant, dans un laminoir Assel, un dispositif étant prévu, dans la direction d'entrée avant le laminoir Assel, pour réduire le diamètre et/ou l'épaisseur de paroi de la partie d'extrémité arrière du bloc creux enfilé sur une tige de mandrin, dont les cylindres de pré-réduction réduisant l'extrémité du bloc creux peuvent être appliqués contre le bloc creux et éloignés de celui-ci, caractérisé en ce que les cylindres de pré-réduction sont appliqués, lentement et de façon continue, contre le bloc creux avec une vitesse de réglage telle que la course axiale (LNEL) pour l'action des cylindres de pré-réduction, mesurée du point d'impact des cylindres de pré-réduction sur la surface du bloc creux jusqu'à l'extrémité du bloc creux, vaut : L NEL = 0,8......2,0D H avantageusement L NEL = 1,0......1,25D H
    Figure imgb0018
     DH désignant le diamètre externe du bloc creux avant l'entrée dans le laminoir Assel.
  2. Procédé selon la revendication 1,
    caractérisé en ce que, comme valeur de référence pour le diamètre du cercle tangentiel entre les cylindres de pré-réduction dans l'état appliqué, sont appliquées les relations suivantes :
    - pour des épaisseurs de paroi moyennes ( D L /S L ≤ 12
    Figure imgb0019
    ) D NEL = D M + (1,8.....2) x S H SH E = (0,9.....1,0) x S H et
    Figure imgb0020
    - pour de faibles épaisseurs de paroi (DL/SL > 12) D NEL = D M + (2,0.....2,2) x S L SH E = (1,0.....1,1) x S L ainsi
    Figure imgb0021
     que
    - pour des blocs creux à paroi mince D NEL = a + b x D HP [mm]
    Figure imgb0022
     où :
    - DNEL est le diamètre du cercle tangentiel entre les cylindres de pré-réduction dans l'état appliqué,
    - SH est l'épaisseur de paroi du bloc creux,
    - SHE est l'épaisseur de paroi réduite théorique à l'extrémité du bloc creux,
    - DL est le diamètre du bloc creux après le laminoir Assel,
    - DM est le diamètre de la tige de mandrin,
    - SL est l'épaisseur de paroi du bloc creux après le laminoir Assel,
    - DHP est le diamètre du cercle tangentiel entre les cylindres Assel au point haut dans la position de travail, et de plus :
    a = 0 à 10, avantageusement 6,35
    b = 0,9 à 1,0, avantageusement 0,938.
  3. Procédé selon les revendications 1 et 2,
    caractérisé en ce que les cylindres du laminoir Assel fonctionnent avec un faible angle d'avance γ entre 3 et 14 degrés, avantageusement entre 3,5 et 6,0 degrés.
  4. Procédé selon les revendications 1 à 3,
    caractérisé en ce que la vitesse périphérique des cylindres du laminoir Assel est réglée à vU = 1,5 à 6,0 m/s, avantageusement 4,0 à 4,5 m/s.
  5. Procédé selon une ou plusieurs des revendications précédentes,
    caractérisé en ce que, pour le laminage de loupes à paroi mince dans le cas d'une courte partie de lissage, les cylindres sont fabriqués avec un grand angle de sortie, et pour un écartement, mesuré au point haut, DHP des cylindres du laminoir Assel l'un de l'autre de DHP = 90.....150 mm, une longueur de partie de lissage LK = 10.....50 mm, avantageusement LK = 20.....30 mm, est prévue, et pour un écartement de DHP = 150.....200 mm, une longueur de partie de lissage LK = 20.....80 mm, avantageusement LK = 30.....40 mm, est prévue, l'angle de sortie des cylindres Assel, relativement à la partie de lissage, valant entre 4 et 6 degrés.
  6. Procédé selon une ou plusieurs des revendications précédentes,
    caractérisé en ce que, pour le laminage de loupes à paroi mince, on a : δ = δ nom + 0,0.....1,5 degré, avantageusement δ = δ nom + 0,3.....0,7 degré,
    Figure imgb0023
    δnom désignant l'angle d'écartement déterminé par la construction du laminoir pour le calibrage des cylindres.
  7. Procédé selon une ou plusieurs des revendications précédentes,
    caractérisé en ce que, avant l'application des cylindres de pré-réduction, les cylindres sont déplacés dans une position à proximité de la surface du bloc creux, en ayant pour le cercle tangentiel des cylindres pré-réglés : D NELO = D H + 4.....20 mm, avantageusement D NELO = D H + 8.....16 mm.
    Figure imgb0024
EP95250149A 1994-08-24 1995-06-23 Procédé pour laminer des blocs creux dans un laminoir de type Assel Expired - Lifetime EP0703014B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4431410A DE4431410C1 (de) 1994-08-24 1994-08-24 Verfahren zum Walzen von Hohlblöcken auf einem Asselwalzwerk
DE4431410 1994-08-24

Publications (2)

Publication Number Publication Date
EP0703014A1 EP0703014A1 (fr) 1996-03-27
EP0703014B1 true EP0703014B1 (fr) 1997-12-10

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EP95250149A Expired - Lifetime EP0703014B1 (fr) 1994-08-24 1995-06-23 Procédé pour laminer des blocs creux dans un laminoir de type Assel

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US (1) US5642638A (fr)
EP (1) EP0703014B1 (fr)
JP (1) JPH0866703A (fr)
KR (1) KR960007036A (fr)
CN (1) CN1118286A (fr)
CZ (1) CZ217595A3 (fr)
DE (2) DE4431410C1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19732444C1 (de) * 1997-07-22 1998-10-22 Mannesmann Ag Verfahren zur Vermeidung von Verlusten an den hinteren Rohrenden von in Asselstraßen gewalzten Warmfertigrohren
DE19748920C2 (de) * 1997-10-30 2003-10-09 Sms Demag Ag Verfahren und Vorrichtung zum Verringern der Wanddicke eines Hohlblocks
AU2003903206A0 (en) * 2003-06-23 2003-07-10 Anthony Kastropil Apparatus for reducing the diameter of round pipe and tubing
JP4716206B2 (ja) * 2009-08-11 2011-07-06 住友金属工業株式会社 ３ロール式マンドレルミルを構成する圧延ロールの圧下位置調整装置及び継目無管の製造方法
DE102022004111A1 (de) 2022-11-03 2024-05-08 Zhozef Rotenberg Verfahren zum Schrägwalzen von Rohlingen mit der im Walzkaliber wirkenden axialen Zugkraft

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1096090A (fr) * 1953-03-27 1955-06-08 Procédé de rétrécissement du diamètre extérieur aux extrémités des ébauchespour la fabrication des tubes sans soudure et dispositif pour la mise en oeuvre dudit procédé
JPS59212106A (ja) * 1983-05-17 1984-12-01 Kawasaki Steel Corp 継目無鋼管の管端減肉圧延装置
DE3533119A1 (de) * 1985-09-17 1987-03-26 Kocks Technik Schraegwalzgeruest zum walzen von hohlbloecken
DE3823135C3 (de) * 1988-07-05 1995-05-04 Mannesmann Ag Methode und Anordnung, durch Walzen den Außendurchmesser und die Wanddicke einer hauptsächlich zylindrisch gehohlten Rohrluppe zu reduzieren
DE4242423C1 (de) * 1992-12-11 1994-01-05 Mannesmann Ag Vorreduktionseinrichtung

Also Published As

Publication number Publication date
US5642638A (en) 1997-07-01
CZ217595A3 (en) 1996-03-13
DE59501098D1 (de) 1998-01-22
DE4431410C1 (de) 1995-11-16
JPH0866703A (ja) 1996-03-12
KR960007036A (ko) 1996-03-22
CN1118286A (zh) 1996-03-13
EP0703014A1 (fr) 1996-03-27

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