DE1909881A1 - Process for casting metallic hollow bars - Google Patents

Description

- 2210 - Process for casting metallic hollow strands

The invention relates to a method for casting metallic hollow strands in a continuous mold, in which a mandrel is arranged protruding. To form a uniform In a known method of a coolant, the skin on the inside and outside of the hollow strand is the mandrel flowed through. On the other hand, there is the risk of shrinking of the strand is reduced on the mandrel, the mandrel is conical.

Between the mold wall and the outside of the strand, the shrinkage gap grows with increasing cooling, which increases the heat transfer and thus the cooling of the strand is reduced. This stable state between shrinkage and heat transfer is between The mandrel and the inside of the pipe are not given, as they are here with Increasing heat transfer increases the shrinkage and, in turn, increases the heat transfer, etc. instead of self-regulation this state tends to become increasingly unstable until the hollow strand shrinks onto the mandrel. In order to avoid this, the conicity of the mandrel would have to be such be large enough that there is a sufficient safety gap for each pail against shrinking is guaranteed so that the above The reinforcement effect described does not extend to shrinking can continue. A large shrinkage gap, however, increases the heat transfer and thus the casting speed too restricted.

The aim of the invention is a method for casting metallic Hollow strands with a continuous mold and a mandrel which protrudes into the continuous mold and in which at the lowest possible Shrinkage gap and thus a high cooling rate a shrinking of the hollow strand is avoided According to the invention, this is achieved by the diameter of the mandrel before the start of a relative movement between the hollow strand and the mandrel is reduced and expanded again to the original dimension following the relative movement.

009838/0963

In a further development of the invention, the Born is at step by step resulting strand funding each gate start of this Promotion reduced in diameter and expanded back to the original size after promotion.

However, the process is also applicable to continuous strand conveyance applicable when the mandrel executes an oscillating movement. The mandrel is then in each case before the start of its return movement Diameter decreased and before the start of being aligned with the strand Forward movement expanded again.

In this way, the sliding of the hollow strand over the mandrel is made considerably easier. Any shrinking on the widened mandrel is through the Durohmesserverrederung of the dome before the start of the relative movement between The mandrel and strand are canceled again, so that the strand feed is disrupted and tearing of the strand skin is avoided.

A device for carrying out the method consists according to the invention of an inner guide part of a casting mandrel, on which a control tube provided with an adjustment drive is mounted, which is concentrically surrounded by mandrel segments held together by spring force, inclined run-up surfaces being provided on the control tube, which are correspondingly inclined surfaces assigned to the segments.

The head tube is provided with a lifting drive, whereby the run-up surfaces run in the longitudinal direction. A lifting drive that can be acted upon on both sides and is connected to a mandrel holder can be used as a lifting drive Pressure cylinder -provided, in the ring piston the control tube is screwed in.

The control tube can also be provided with a swivel drive, with the run-on surfaces across the axis on the circumference des Ro.tres are arranged. A iiierbex can also be used as a drive Pressure cylinder be provided.

009838/0963

If the split mandrel surface is formed by movable segments, it is advantageous to provide guide rollers on the underside of the guide part.

But let us also, one embodiment conceivable, in each case connected between movable mandrel segments with the head tube Segments are arranged, ilxe arcuate cord skin may develop When leaning back, pull the movable segments straight and thus shorten them, which also prevents them from shrinking can be. This effect can be enhanced by the fact that the movable segments protrude in their outer position beyond the dumbbell surface of the fixed segments. The segments can be in As is known, be tapered in funding direction.

The segments are provided with cooling channels, which are flexible . Connections are connected to coolant supply lines.

For secondary cooling of the inside of the hollow strand are in the lower Area of the guide part arranged nozzles, which have a central Durohgang opening in the guide part are supplied with cooling water.

Exemplary embodiments are shown in the drawing. Show it

Flg. 1 a vertical section through a casting mandrel protruding into a mold,

2 shows the cross section of a dome with movable segments,

Fig. 3 shows the cross section of a dome with fixed and movable Segments,

Fig. 4 shows the cross section of a dome with fixed segments and protruding movable segments and

5 shows a vertical section through a hollow continuous casting plant with two molds

009838/0963

Above the passage opening of a mold 1, a boron holder is arranged, in which a guide rope 3 is inserted. A lifting tube 4 is mounted on the guide part 3 by means of sliding blocks 5 and is displaceable. The lifting tube 4 is screwed into a ring piston of a pressure cylinder attached to the mandrel 2. On the lifting tube 4 lower and upper inclined® run-up surfaces 9 »9 * are provided, to which correspondingly inclined © surfaces 10, 10 ¹ of mandrel segments 11 are assigned

The mandrel segments 11 are circular around the hiibroha? 4 © ag © © r and are held by lower and upper compression springs 12g, "12® jgiaga. On their upper side are the thorns © gM © nt © 11 In gIhloe ¹ © speaking recess of the Dornkalt era 2®, nfg © a © iis © no Mi underside of the mandrel segments are supported on © iaoa 'Afesats & ®ίΰ part 3. 11

In the age of thorny 2 a water tank ¹ 13 vmä © ia collector 14 are provided * The cooling water tank: *? 13 is pipes 15 and 'flexible connections 16 suit in the tone BesagQgsoatQa pre-geeehaaen cooling water channels 17 veTshmiämno DtQ SiüaluGfDiD 17 are connected via a lower passage 18 ait EüM12ssmäl © a 19 _for which on the outside ä®s DQsmBQ§n®w "s® 11 ■ v-Qsg are, in the cooling channels 19 feefinäea siola l®säs ° äMg®T 20 increase the ¥ a8ser speed _e the löilil & gsiäl® 19 £ 3iaä flexible Änseliliieee 21 and line a 22 old eloa KISälw ⁷ 14 connected,

A coolant supply line 23 is connected to a duct part 3, aureh. 3 nozzles arranged at the top of the guide part, 25 giar-Suisim the inside of the strand with cooling water fereosgt ti © rä © a _s . In the underside of the guide part, hollow 26 sns Steaag are stored.

In the alternative shown in Fig. 3 & usfülming ä®m Bo: are between the radially movable segments. 11a feet 26 arranged, which on their top and bottom with

009838/096 3 ORIGINAL BATHROOM

? Associated ührimgsteil 3 I _s la same Weis © are fixed in fig »4 arranged between the bewegliehen segments 11b segment © 27 is connected at its top iiaeL underside with d © a lütoungsteil 3, characterized $ DAB dl © ISgWBgXiOhQH Sege © nt © 111) iifoer the meat surface of the solid s © ga © sit © hinaiisragiiiij disfigured a corrugated © surface _s additionally counteracted by the sefaksr of shrinking

With the feesoiirielenen ¥ orriciitimg .feana the ¥ © rfahrea v / ie follows being carried out

Yes the mold 1 is continuously filled with Seha @ la © egg. The mold and the mandrel holder 2 with the mandrel have been moved continuously in an ossilating manner, where "b © i is given in the conveying direction" in & lai © 3alauf between mandrel and hollow frame 28. During this phase, the piston 7 "is located and there is the lifting rotor 4 in the upper position. The surfaces 10, 10 ^s of Domsegiaent © are pushed onto the running surfaces 9 _f 9 ⁸ * The mandrel is widened. Yor the HiioMiub of the mandrel of the Kolls © a 7 duroii Beaufsehlaguiig opposite to the lower position moves Di _o © Eingfedern 12, 12 'aiehen The 3us & Ma © n segments, the Dorndurehmesser any misuse is reduced _e

In the case of discontinuous G-ielsn, the mandrel is during the running-in the melt widened after the inlet ended is, the mandrel is reduced in diameter, so that the cast Piece can be conveyed out. A® is particularly advantageous here © Facility is shown in Pig =, 5 »This figure shows two next to each other © continuous molds 1 and 1a, on which intermediate containers 29 and 29a are arranged. The intermediate container are alternately by a swivel channel 30 Ladle 31 is charged. The facility has the advantage that Even with this type of process, the melt can continuously run out of the pouring ladle, which causes problems due to freezing of the pan stopper.

0 09838/0963

Claims (1)

° 2210 ■ - Claims 1 »sum method GieSeii vc" n laetelXisoii® "Holilstsasigoa eit-ended mold and a in II® Biaseliliiiiflsolsill © liiaeinrgigsad arranged mandrel, swissJaen d © a gsgoesonsa Straag IMD doe mandrel a sclirittweise Eelativ" bQ ^T; j @ giffiig si; attfiiad © tp da = marked by the fact that d®E Bqct. voz ¹ beginning of the relative movement in the BttgOiHsesssE iferaiadd ^ t mid "i® connection to the relative movement -is expanded again to the η dimension. 2 «method according to claim. "I ₈ Step-by-step travel of SteengföEd © Eiia, g des D © xa Start of funding in BurehnsessoE ¹ T @ Ei? Ing®r "fe Method according to claim 1, dadursli gskeimgeiclmdtp that with continuous strand conveyance and osaillisrsnd mandrel _f the born is reduced before the beginning of the hticKbsvjogiang and widened before the beginning of the forward movement directed with the S-feraaglawoguag glsieli 4 · Device for carrying out the method ₀ see below. © iaen of the preceding claims ₉ , characterized in that on an inner guide part of a G-ießdoraes © ia with a drive-provided control tube is mounted _s v <BlGh, ®s of boras © gaenten held together by spring force ι with inclined on the control tube Provided on the running surface, which are appropriately inclined! Surfaces on the SogM © a = ten are arranged. 5 · Device according to claim 4 »characterized dadurcli ₉ that the" control tube is provided with a linear actuator ₉ Xirebei extend the run-on surfaces in the longitudinal direction of the tube. 6. Device according to Anepruoh 4 _t thereby gekennsei © 3binat§ that 009838/0963 the head tube is stranded with a pivot drive, whereby
the run-up surfaces across the Aohse on the circumference of the pipe
are arranged. 7. Apparatus according to claim 4ι 5 or 6, characterized in that a double-sided actable pressure medium cylinder is provided as a drive for the control tube, the piston with
connected to the head tube. 8. Device according to claims 4 and 5, characterized in that that the control tube is screwed into an annular piston, which is received in a bridge center cylinder attached to the dome holder is. 9 _β device according to one of claims 4 to 8 »gekennseiolmetj that the entire Dornofeerflache of" movable Segments is formed. eVQ ^ E? ichtisag nGoii an öqz? ÜLsisprüeJa © 4 "marked as Q ₉ by the fact that üle Dosaoessflaeiio von elsweöliselad aisordinated Tmobilliehan Segments . Associated with the Steiierrokr" is formed o t _} that the ii Segments in ihsQT outer Stsllimg with the fixed egmoaten eino geiaeiuoas® Msntelfläsh © form _β 12o ¥ oETahung nasii'AneprusJa 1O ₉ iaduseh gekesnzsicMiet that the teswagliohen segments in their exterior. Position about the Maat θ If lache &<& τ solid Sogaente protrude » n & öh öiaea 4qs claims 4 to 12 ₉ characterized in that the segments © are provided with Kiüalkanäien,
which mi flexible Ansshlüsse coolant supply lines is söiiloseen are. 009838/098 14. Device according to one of Claims 4 to 13, characterized in that the guide part is provided with a central passage opening to which a cooling water feed line is connected, with nozzles for secondary cooling of the inside of the hollow strand being connected in the lower area 15. Device according to one of claims 4 to 14 »characterized in that guide rollers are mounted on the underside of the guide part. 009838/096?