DE1602031C3 - Composite roller - Google Patents

Description

²² A

1.4 b U% Α

3 ⁱ⁹ 6 to ² I ² A θ '* "'Se""Invention is based on the object

emnaii, uau uci ^. "^ ₆ " - - - Dimensions eeeianet isi, auucicn rn ».» ... - ··

Roll shell (lift) to withstand constant deflections, especially

less than 0.02 · /. Ni, _{45 especially} with a certain penetration

less than 0.02% Cr, withstanding the _{cliché changes in stress}

3.0 to 3.5 ° / ₀ C, sfch with a constant η direction

acting on the roll shell, ™ «* £ ^

· R ^ nsnrüchuneswechsel have an effect, for example

and the remainder Fe with incidental impurities ^ "^, ^^""""ββη. which shows during the turning and that the mottled gray cast iron of the middle roller shell (lic) of zero or a negative Change value.

at least 0.02 to 0.05% Ni. _{The solution to this} problem is found according to the invention

at least 0.02 to 0.05% Cr _d . _{that the} composite roller consists of three ^ l -

and the remainder of gray cast iron in the same addition

composition like that of the inner roller - as with composite rollers oeKaniu, aua L ₁ Uu ₆ U, -, _uv . mantels {lib) is composed. middle roll shell made of mottled gray cast iron unc

the inner roll shell, as known from composite rolls, made of low-alloy, softer gray 6o casting consists, with the total volume of the middle and inner roll mantle to achieve a sufficient compressive prestress in the outer egg ■ - .. «; i - .; c viprnvil as cross as there

The invention relates to a composite roller with waiumiianui · ... «..“ ._

is at least two volume of this roll shell made of different cast materials.

existing on iron basis, each by centrifugal 65 On the basis of the proposed measures läO

cast manufactured, concentric roll shells, a Harl is used for the outer roll shell

Mn the contact surface of which use an intermetallic casting alloy, the ground hard

t and is called the outer surface for the processing of web material:

is particularly suitable and resistant. Since the chilled cast alloy cannot absorb major tensile stresses, which mainly occur when the roll bends under the influence of an external load, the outer roll shell is placed under axial compressive stress with the aid of the large-volume inner shell made of low-alloy, softer gray cast iron. The compressive prestressing of the outer roll shell leads to the advantage that the axial expansion that occurs when the roll is deflected is opposed by a resistance, whereby, in contrast to single-shell rolls, deflections only occur when there is a larger external load, and that, moreover, despite the use of the with regard to the Tensions to be absorbed by unfavorable chilled cast iron, larger external loads can be absorbed with the composite roller. If the composite roller according to the invention is used in connection with a device for the adjustable elimination of the deflection, this device only needs to be actuated to a lesser extent or only made smaller due to the existing resistance to deflection of the composite roller.

* In a further embodiment of the composite roller according to the invention it is proposed that the sum of the Wall thicknesses of the roll shells one third to one tenth of the outer diameter of the composite roll hugs

A preferred embodiment of the invention is thereby in its chemical composition characterized in that the chilled cast iron of the outer roll shell

l, 4bisl, 7 ° / ₀ Ni,

1.9 to 2.2 ° / ₀ Cr,

3.6 to 3.8 ° / o C,

0.4 to 0.5 _^0/0 Si

and the balance being Fe with incidental impurities, that the cast iron of the inner roller is less than 0.02 ° / ₀ Ni, less than 0.02 ° / ₀ Cr, 3.0 to 3.5 _^0/0 C, 2.0 to 2.9 ° / ₀ Si

and the remainder Fe with incidental impurities and that the mottled gray cast iron of the middle Roll shell

at least 0.02 to 0.05 ° / ₀ Ni, at least 0.02 to 0.05 ° / ₀ Cr

and the remainder of gray cast iron in the same composition as that of the inner roll shell is composed.

The invention is described below on the basis of exemplary embodiments in conjunction with the drawings explained in more detail. It shows

F i g. 1 a schematic view of a rotatably mounted composite roll according to the invention,

Fig. 2 is a cross-section along line 11-11 in F i g. 1 on an enlarged scale,

3 shows an enlarged longitudinal section along the line IU-IH in FIG. 2,

F i g. Figure 4 is a side view of a calender arrangement with a composite roll shell according to the invention and a device for compensating for roll F i g. 5 is a partially sectioned side view of two rolls forming a press nip with one another; F i g, ύ two rollers together forming a press nip in partially sectioned elevation and F i g. 7 shows a schematic representation of the in the arrangement according to FIG. 6 occurring loads and powers.

According to FIG. 1, a composite roll 10 is provided with a multi-shell roll shell 11 which has an axial length L ίο. On the roll shell 11 on both sides by means of screws ß side parts 13 and 14 with molded shaft journals 15, 16 are attached to support the roll rotatably about its axis C in bearings 17,18 on bearing blocks F, F. According to FIG. 2, the multi-school structure 11 of the composite roll consists of a chilled cast iron outer jacket 11 ″, a low-alloy or non-alloyed gray cast iron inner jacket 116 and a middle roll jacket Hr made from mottled gray cast iron. The average shell Hr is so over its entire length to the same length outer casing 11a and the inner shell 116 d connected by intermetallic compounds 11 and lie. The layered overall arrangement has an outer diameter D and a wall thickness R. »5 For a preferred application, the composite roller produced by centrifugal casting has considerable dimensions, both in the outer diameter D, which is, for example, up to 140 cm, and in the wall thickness R, which depends on Outer diameter D and axial length L can be up to 30 cm and can be expressed in proportions of one tenth to one third of the outer diameter D. The axial length corresponds to z. B. the usual dimensions for paper machines between about 250 and 1000 cm. The values for diameter D and length L are best given in the ratio that forms the decisive parameter for each application and is in the range between 4: 1 to 15: 1 for practical cases. The main chemical components for the outer jacket are Πα: 1.4 to 1.7 ° / ₀ Ni; 1.9 to 2.2 ° / ₀ Cr, 3.6 to 3.8 ° / ₀ C; 0.4 to 0.5 ° / ₀ Si. The rest consists of Fe and incidental impurities.

The inner jacket 116 contains less than _{0.02 ° O} Ni; less than 0.02 ⁰ I ₀ Cr and incidental impurities.

The middle jacket lic consists entirely of mottled gray cast iron and contains on average at least 0.02 to 0.05 ° / ₀ Ni and at least 0.02 to 0.05 ⁰ Z ₀ Cr. The remainder consisting essentially of the Graugußzusammensetzung of the inner shell 116. It is desirable, lic the casts for the middle and inner sheath and to make of the same total charge of cast iron 116, which is about comprises two to four times the volume of the particular for the outer jacket Hartgußlegierung.

From Fig. 3 shows that the outer jacket 11 "has a radial dimension /? ,, the combination of the wall thickness of the middle and inner jacket Hc or 116 has the radial dimension R ₃ or 6, while the combined wall thickness of the outer jacket and the metallic bonding layer Ht / is marked with «. The radial dimension /? _; , is much larger than R ₁ ; Despite the schematic representation, this relationship also applies in principle to practice. The two metallic bonding layers 1 1 and 2 are shown exaggerated.

For the production of the composite roller in the centrifugal

; USS using a permanent mold having a b into the inner cladding portion \ easily incorporated

metallic molding box and one located therein. The one in question for the gray cast iron

Form-finished or a mende lined with molding sand two to four times as large a volume as for the

Molding box. The initially molten iron outer chilled cast iron shell, which is based on the

alloy, the composition of which in a casting 5 above example 4000 kg for the middle

pan sample for the outer jacket Wa an- jacket and approximately 8000 kg of cast iron for the

corresponds to given values, is then in the form of inner jacket Wb makes, leads to the

poured. The shape is so well supported in rotation and under

assumes that an annular, liquid metal compressive stress is held. In the case of the outer

existing body with an approximately constant radius io chilled cast shell 11 "

R ₁ forms, which is then allowed to cool relatively quickly. It is not just about axial stresses, but rather

The second sprue is in a known manner through- also around circumferential stresses, so that the outer

out as long as the metal shell that is cast first can retain its hardness and other

is still in a plastic state. On the one hand, it is not exposed to tensile forces when it is used as

It is important, however, one looks too strong leaching of the i ₅ load-bearing medium.

To prevent alloy components, which is why one in F i g. 5 is a two-roll, the first sprue cools a little longer than shown after a press nip-forming arrangement. One of the prior art is common. A suitable flux is applied to the inner surface of the upper roller 20 in small quantities with loading devices, which are indicated schematically by the arrow A pointing towards the two Rich outer shells (at the point L ₁ according to FIGS. 2 and 3) . After brought to a better metallurgical bond Wd F i g. 4, the bottom roll supports 11 B of a calender between the first and second castings Ha or rollers 21 located thereabove, 22, 23,24, 25, and to obtain Hc. 26. It is a typical calender

In an exemplary game about 4000 kg were arranged, in the case of the one with the lower roller 11 B

Metal in the first cast 11 α and about 4000 kg of gray as the nip NC formed, a pressure acts. To

cast iron in the second cast (according to Hein Fig. 5 forms the lower roller 11C together with the

F i g. 3) used. The second casting charge has in the upper roller 20 a press nip N _p along the nip

the ladle has a composition that corresponds to the previous line / VJL ₅ , which is like the cleavage line NL ₄ at the gap

The values given for the inner jacket Wb correspond to NC according to FIG. 4 transversely to the direction of feed

speaks. The pouring of the second casting batch extends to the roller assembly.

Production of the middle jacket Hr does not lead to FIG. 6, the split line / VL ₈ runs transversely to

only in the formation of the metallurgical bond to the feed direction of the arrangement and is accordingly

the point Hi / to a reheating of the outer burdened the downward arrows, the one

Shell, but also for washing out one between an upper Prcßwalzc 30 and a lower one

A certain proportion of nickel and chromium alloy, evenly distributed load

consist of the chilled cast iron, so that the middle should represent. The upper Prcßwalzc 30 is with

Coat Hr receives a mottled structure in which shaft journals 31 and 32 are provided, which are in thrust bearings

the total to be found proportion of nickel and 31 B and 32 B are supported. The camps are over

Chromium burdens and directs at least more than trace amounts of fraud in the area of load facilities PL

below 0.02 ° / ₀ and under basic 40 stress on the shaft journals 31, 32 further,

Laying of empirical values at least 1/2 to so that there is an even distribution of pleasure lengthways

_{Spulllinic / VL 0} results in 0.05 ", Ό nickel and at least 0.02 to 0.05" / 0 chromium.

matters. The schematically drawn binding The lower roller 110 consists, like uuch the rollers

zone H </ consists of a related very HC and llii, from which related to the

thin ice cream with a mottled character, the 45 roller jacket H C described by triple

functionally achieved as an extension of the Melullgczus cast. The roller 11 D sits down

of the outside munich Wa can be unseen, which together from an alloyed cast iron 11 Da,

with the structure of the middle school Hc in the manner of an inner Griuigußmuntel 110 /) and one out

is mixed or fused so that both structures are mixed with cast iron standing withMunlcIllöc.

in the form of fiber strips at L ₁ and L ₁₁ on the 30 The lower roller HO has on its slims with

polished end faces of the roller become visible. Head pieces 38, 39 which are provided with sleeves and which are mounted on bearings 36

Area hui a certain rudiulc extent, which and 37 are ubgesUlzl, which u on shaft journals 34

at W _{11 is} exaggeratedly dense, but without the looks and 35 sit. The latter are in a rotary motion

Able stripes, which hindered a constant radial, extend into the lower roller HO

Have dimension. The third casting turns 33 and reveals executions that take place over a current * *

again by using a flux the means exert a controllable pressure, like the «

Desired mechanical bonding and the position Hc schcmutisch for the roller Hu is shown in Fig.4

supports. The compound munich of the Wulzellß is on one

When the drcischuligc roll shell Π cast bead cores (· 4 rotatable gelugerl, un demichtungci

and has cooled sufficiently, it will fit against the sund · 60 S-4 and S-4a , which have a seal / wiper

shape removed. Then the outer surfaces / 'the core C-4 and the inner groove of the jacket N

as well as the inner surfaces // 'beurbcilcl. The guarantee. This creates an overlap

Gray cast iron of the inner manicl Wb is soft and IUUt pressure zone FP-A for the flow medium, dcssci

Therefore not only the GUltlcn Innenumfungcs pressure directly over the split line NL _t au

// ', but the inner wall of the Walzonmunlcls N' also acts to produce any desired connections 83. Nucl

or edit connections that may be necessary for the F i g. 6 is the direction of the flow pressure

Surrenders of the wind are perverted. Thus, FP can cingetrugenci through the broken lines

the Aufnuhmcbnhrungcn for the screws B (Fig. I) indicated arrows.

The three-shell roll shell 11 ″ of the roll HC according to FIG. 5 contains a stationary core CS which has an axially running groove SS extending essentially over the entire length of the split line / VL ₅ comparable length and a cross-section specified at point PS , which is loaded from below by the pressure chamber FPS at the bottom of the longitudinal groove SS and presses against a free swivel bearing rod RS of the same length, on which a pressure shoe RSS is mounted, which has a rigid surface around the inner circumference of the roll shell 11 "is facing. The pressure shoe is designed so that it holds a film of oil or creates a hydraulic wedge in an oil film, via which the pressure load is transmitted to the inner wall of the roll shell.

As the load diagram according to Fig. 7 shows, the alloyed chilled cast iron outer jacket 11 Ea rests on the inner gray cast iron jacket 11 £ '(which is intended to characterize the middle and inner jacket Hr and lift). The compressive stress indicated by the arrows CL pointing in opposite directions occurs when the central and inner jackets cool down. This cooling process takes place at least partially after most of the shrinkage and cooling of the hard metal jacket 11 Ea has ended. The outer jacket is thus kept under pressure by the material 11 E 'of the middle and inner jacket. If a load occurs only briefly at a locally limited point LL , a measurable deflection could occur in the chilled cast iron shell, which is shown by the broken line UE'a . This perceptible deflection of the outer jacket WEa would cause an at least theoretical increase in axial dimensions. Most important task of the large volume of the initiate and inner jacket and the resulting strength of the softer material of the Miintelansehnittes 11 /; ' consists in keeping the outer I liiitjuillmanlel 11 l'.ii permanently under compressive stress CL so that at least an initial deflection of the specified type is preferably only compensated by a small portion of the pretension.

If the pressure of the fluid is sufficient to deflect the roller downwards accordingly F i g. 7, an upward deflection would occur if the upper loading device against the cleavage line

ίο / VL ₇ presses, should fail briefly. An upward deflection could thus occur to a noticeable extent in the outer casing shell 11 Ea along the split line NL ₇ ; however, the tendency towards such a deflection is only so great that a portion of the compressive prestressing of the chilled cast iron jacket 11a is compensated and tensile stress is not to be feared. It can also be seen that the opposing loads along the nip line NL ₁

ao are significant, while loads in the opposite area of the roll shell are almost complete are absent if any of the above-described work with the pressure of a flow medium Loading devices is used. That means,

as that the roll shell is exposed to considerable opposing forces during the rotary movement in the area of the gap line / VL _7. of which each force alone would be sufficient to cause a certain deflection in the roll shell, whereas the existing opposing forces would cause such a deflection to be minimal. In contrast, the underside of the roller manicl is free from significant stress. There is thus a continuous load change. By using the roller mechanism according to the invention, it is possible to expose the roller to these strong cyclic load changes for a longer period of time without any metallurgical changes inside

• ι «or other undesirable consequences occur.

Here / u 2 sheets of drawings

Claims (1)

* a \ Wtii7pnmantel of at least one other Sneßend cast further inwardly lying roller patent claims: SanS through stronger shrinkage of the inner lying • _ver whale jacket in the axial and circumferential direction below 1 compound roll can be placed with at least two of comparable JT'f _{k "pannun} g., "HiJenen GußwerkstofTen iron base for determining S ^^^""^ π refers to previously erne send, each manufactured by spin casting Under ν _tric shells mU plant Olten divided concentric roll shell * other type of _roll has a ljgcher property. the * "" G ^ Xi compound rolls produced is formed beschTch contact surface an intermetallic bond, and wherein the foreign inG.e ^lverI _{schleißfeste} shell mt Hegende a softer roll shell of at least Cinema. "SIU _neme _US ..P _a tentschrift 2,710,997 chließend cast whale ^ ² further inside! "" casting process for making a Verzenmantel Duuren stronger Schrumpfungt of domestic ^ X ^ designated type is then that Hege ends roll shell in Axial · and peripheral Jundwa ze _auBenl i _egen de roll shell cast richtun " can be placed under pressure preload, initially _{by continuing} since you rchgeke η η ζ calibrate η et that the ver t, and «JgekuhJ ^. ^ ^ compared to the outer collar roll made of three roll shells (1 la, Π c and egenaen _d significantly increased tempe- 1 b) is built up so that the external roller _{cools the composite roller B} em jacket (lla), as known for composite rollers, from ratur g eBt and _dwa , _{M shrinks} the inner Chilled cast iron, the middle roll shell (lic) made of ^Α ™ ^^ _{εηΓηαη1ε} 1 much stronger than the outer mottled gray cast iron and the inner roll » ^e | ^en J _e ^ _alzenmante , _and thereby sets the msmantel (IU), as known with composite _rollers ^{, from 1} ^ nth pressure pretension. . low-alloy, softer gray cast iron, where- total ^ "J ^ ^ _{kn for example} with the total volume of the middle and inner- J ™ ^^ _in connection with E. directions Hegenden roller jackets (llr, 11 «to achieve to the Amvenau g _deflection and / or des a sufficient precompression .m exterior to a ₅ teeinging _{Wa (zen From h fl} lying roll mantle (11 ") zwe, - up to four times by Hange ^ _{within ner} Kalandergroß as the volume of said roll mantle is 3muj _'untergebra FRUITS composite roll known ⁸ 2. The composite roll according to claim, characterized ^ ° ^rdn _D ^ _rchbiegl f _{ng in} the result of external Characterized by the fact that the sum of the wall thicknesses de ^Γ ^ _η ^ ^Γ ° _οαεΓ irregular warming thereby the roller shells (Ha to lic) a third to J 30 young ^ ^ _{from individually} behe.zbaren Tenth of the outer diameter (D) of the composite jgmpensie _{existing inner saddle} i _e mechanically or ^W ? ^e V ^b e ^e : Swa, ze according to claim !, thereby M— against ^^^ m ^ aS ^ g characterized in that the chilled cast iron of the outside gruf tw heating elements supplies electricity Hegenden roll shell (Πω) ³⁵ J * ' ⁵ / _e / _ern outwardly curved circumferential 1.4 to U% Ni. Αϊ «of the roll shell diametrically opposite