US3723198A - Method of straightening elongate inductively heated workpieces - Google Patents

Method of straightening elongate inductively heated workpieces Download PDF

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Publication number
US3723198A
US3723198A US00088548A US3723198DA US3723198A US 3723198 A US3723198 A US 3723198A US 00088548 A US00088548 A US 00088548A US 3723198D A US3723198D A US 3723198DA US 3723198 A US3723198 A US 3723198A
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United States
Prior art keywords
workpiece
straightening
heating
inductor
workpieces
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Expired - Lifetime
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US00088548A
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English (en)
Inventor
G Seulen
F Reinke
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SMS Elotherm GmbH
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AEG Elotherm GmbH
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    • 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

Definitions

  • This invention relates to a method and apparatus for straightening elongate workpieces which are held at each end and rotated while being inductively heated by a linear inductor of the type wherein straightening is accomplished by mechanical straightening means, such as straightening rollers, straightening beams or sliding blocks.
  • the optimum time for applying the straightening devices in any particular instance can be readily found by a few simple trials. In any event contact by the straightening devices should not be made at least until immediately before the inductor is shut down, and may alternately be made at the same time or just after the inductor is shut down. Applying the straightening devices at this time ensures that the stresses in the workpiece can relieve themselves freely and that the rolls or other straightening devices are not applied until this has occurred.
  • a particular advantage afforded by the method of this invention is that it can be performed in equipment such as described in the above-mentioned Seulen et a1.
  • application containing straightening rolls that can co-operate with the magnetic forces to straighten during heating.
  • the application of straightening rolls is preferably automatically controlled by reference to a time program and the rolls or other devices are advanced at the desired point in time, be it immediately before, during or immediately after the shut-off of the inductor.
  • the apparatus consists of a tilting workholder unit, equipped with workholding means for mounting the elongated workpieces and with straightening rolls, for conveying the workpiece from a heating station facing the stationary inductor to a quenching station facing a quenching spray in a simple tilting motion that can be rapidly performed.
  • FIG. 2 shows a side elevation view of the workholding unit
  • FIG. 3 shows an alternative form of construction of the workholding unit
  • FIG. 4 shows a side view of a tilting unit according to the invention.
  • a conventional current inducing apparatus having a linear inductor 2, and a return conductor 4 is provided adjacent workpiece 1 for inductively heating the workpiece.
  • Inductor 2 is preferably fitted with laminated plates or a pressed soft iron magnetic core to provide a magnetic circuit generally indicated at 3.
  • the transient direction of flow of the current through the inductor 2 and return conductor 4 and the current induced in the workpiece 1 which is preferably rotating in the direction of the arrow 8 are indicated by a cross and a dot in a circle, the cross designating a current into the plane of the drawing. It is, of course, understood that the current directions and direction of rotation can be reversed if desired.
  • the workpiece 1 consists of a non-magnetic material or a material at a temperature above the Curie point, then the work will experience a thrust acting in the direction indicated by the arrow 7.
  • this thrust can be utilized for straightening the workpiece by providing stops, such as straightening rolls 5 and 6 against which the rotating workpiece is magnetically urged.
  • the rolls are not advanced during heating so that straightening takes place not during heating but rather the magnetic forces are allowed freely to take effect during inductive heating while the straightening rolls are in a retracted position.
  • the straightening rolls and 6 which are movable as indicated at arrows 9 are not advanced into contact with the rotating workpiece in the direction of the arrow 10 until, at the earliest, immediately before inductor 2 is shut'otf.
  • FIG. 2 For performing the method according to the invention in the described arrangement in a continuous production line it is preferred to make use of apparatus which is also conventional, a side view of one of which is shown in FIG. 2.
  • apparatus Immersed in a tank 11 filled with a quench 12 is an indexable workholder unit 13 which permits enlongated workpieces 14 to be horizontally mounted.
  • Unit-13 is rotatable about its longitudinal axis, and distributed about its periphery there are provided at least three or more individual workholders.
  • Each workholder supports the workpieces 14 on rolls 15 which participate in indexing motions of for example 12, 90, 60 or 45, depending upon the number of workholders distributed around the periphery.
  • An inductor 16 such as the one shown in FIG. 1, is provided adjacent unit 13 for heating workpieces preparatory to straightening and hardening as described above.
  • workholder unit 13 is indexed 90 in the direction indicated by arrow 17.
  • the workpiece 14 including the straightening rolls 15 are thus immersed in quench 12 after inductive heating and straightened while being quenched.
  • an additional spray 18 may be provided for accelerating the quenching effect.
  • the workpiece continues to be rotated in the direction of the arrow 19 while it is being quenched, but rotation in the opposite direction would be equally acceptable.
  • the indexing intervals of the workholder unit are determined by the time needed for heating, since at least three times the heating time is available for quenching if the workholding unit is fitted with four separate workholders. However, if the workholder unit is provided with more workholding positions, then the quenching time may be further prolonged in relation to the heating-up time. It may be desirable to provide a supplementary quenching spray 18a in direct proximity with the inductor 16 to permit quenching to start with a minimum of delay after heating has been completed, and without having to wait for the workholding unit to complete its indexing motion.
  • the rolls 15 are not advanced into contact with the workpiece during the performance of the process, as shown in the drawing, until the cooling and quenching process begins or just before.
  • the workpieces may be vertically mounted, as shown in FIG. 3.
  • the workpieces 14 are each heated in turn by an inductor 20 at a first station of the workholding unit. After heating each workpiece is first indexed to the quenching spray 22 while continuing to rotate in the arrowed direction, and then to position adjacent a second sprayer 23.
  • the rolls 15 are not, of course, applied to the workpiece 14 until the inductor 20 has been shut off or just before or until cooling or quenching begins.
  • FIG. 4 is a side elevational view of apparatus which may be more particularly used when quenching is to begin as quickly as possible after heating has been completed, and principally when the workpiece is to be surfacehardened.
  • the apparatus illustrated is a tilting workholding unit 24 which is tiltable in bearings 25.
  • the shaft that works in these bearings 25 may be vertical or horizontal, the tilting unit either swivelling in the horizontal or tilting in the vertical.
  • the tilting unit carries two workholders for the ends of a workpiece 26 that is to be treated. Straightening rolls 27 can be forced into contact with the workpiece in the direction indicated by the arrows 28. In the heating position the workpiece 26 is held facing inductor 29..
  • the tilting unit When the heating process is concluded the tilting unit is tilted in the direction of the arrow 30 and thus carries the workpiece 26 without delay into the quenching position facing the quenching sprayer 31.
  • the straightening rolls 27 in this apparatus are likewise advanced in the direction of the arrows 28 into contact with the workpiece 26 at the instant the inductor 29 is shut off.
  • the tilting unit may also be so disposed that the workpiece is lowered from an upper position downwards, substantially vertically.
  • This latter arrangement may particularly be used when quenching of the workpiece is to take place in an agitated liquid quench and the surface of the quench is at a level high enough to permit the tilting unit to immerse the workpiece bodily in the quench.
  • the tilting workholding unit For loading and unloading the tilting workholding unit it may be moved into a zero position 32 where a hardened and straightened workpiece can be removed and an untreated workpiece substituted. During this process the straightened rolls 27 are withdrawn.
  • a method of heating and straightening an elongated metal workpiece comprising the steps of:
  • a method as in claim 1 further including the step of quenching said workpiece after said heating.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Heat Treatment Of Articles (AREA)
US00088548A 1969-11-25 1970-11-12 Method of straightening elongate inductively heated workpieces Expired - Lifetime US3723198A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19691958994 DE1958994A1 (de) 1969-11-25 1969-11-25 Verfahren und Vorrichtung zum Richten langgestreckter induktiv erhitzter Werkstuecke

Publications (1)

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US3723198A true US3723198A (en) 1973-03-27

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US00088548A Expired - Lifetime US3723198A (en) 1969-11-25 1970-11-12 Method of straightening elongate inductively heated workpieces

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US (1) US3723198A (de)
JP (1) JPS4915543B1 (de)
DE (1) DE1958994A1 (de)
GB (1) GB1303322A (de)

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Publication number Publication date
DE1958994A1 (de) 1971-09-16
JPS4915543B1 (de) 1974-04-16
GB1303322A (de) 1973-01-17

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