RU2149718C1 - Rolling stand - Google Patents

Abstract

FIELD: rolled stock production, possibly in shops for cold and hot rolling of ferrous, non-ferrous metals and non-metallic materials. SUBSTANCE: rolling stand includes frame, rolls, roll drive unit, magnetic conduits, windings and electric current source. Rolling stand also includes one pair of -shaped solenoids, one pair of flat solenoids with rectangular core embracing rolls and turned one to another by similar poles relative to rolling plane. Stand frame is combined with magnetic conduits. Pressure rolls are in the form of cores of permanent magnet provided with control windings and embraced by cylindrical magnetic conduits connecting their similar poles. Additional -shaped solenoids arranged on lateral faces of above mentioned -shaped solenoids have control windings. -shaped solenoids are rigidly joined one with another by means of non-magnetic supports and non-magnetic foundation of stand with the aid of screws. EFFECT: improved design of stand, high quality of rolled strip. 3 dwg

Description

 The invention relates to rolling production and can be used in the shops for hot and cold rolling of ferrous and non-ferrous metals, as well as for rolling non-metallic materials.

 Known rolling mill containing a frame, rolls, drive rolls / A.N. Tselikov "Machines and assemblies of metallurgical plants", vol. 3, Moscow: Metallurgy, 1981 /.

 The disadvantages of the known stands are the inevitable deflection of the rolls during rolling, as well as the elastic deformation of the elements of the stand, which leads to a change in the preset gap and the appearance of defects such as “wave” and “box”, longitudinal and transverse thicknesses of the strip.

 Also known is a stand containing a bed, rolls, roll drive, electric current source, magnetic circuit / a.c. N 737032 M. cl. 21 B 1/02, publ. 1980 /.

 The disadvantage of the known stand should include the effect of elastic deformations of the elements of the stand / bed, pressure screws, roll pads / on the value of the pre-set gap and, therefore, on the quality of the rolled strip.

 The purpose of the invention is the improvement of the design of the stand and improving the quality of finished products.

 This goal is achieved in that the rolling stand containing the frame, rolls, roll drive, magnetic cores, coils and an electric current source is equipped with at least one pair of U-shaped electromagnets, one pair of flat electromagnets with a rectangular core, covering the rolls and located in relation to each other to each other with the same poles relative to the rolling plane, the stand frame is aligned with the magnetic cores, the pressure rolls are made in the form of cores of permanent magnets equipped with control coils eniya cylindrical magnetic cores and covered by connecting their like poles on the sides of the U-shaped electromagnets installed additional U-shaped electromagnets equipped with control coils, U-shaped electromagnets are rigidly interconnected by a nonmagnetic nonmagnetic supports and stand foundation using screws.

 The implementation of the pressure rolls in the form of cores of permanent magnets equipped with control coils allows the rolls to be magnetized, i.e. create and regulate the rolling force by applying short current pulses of the corresponding sign to the coils, in which the cast permanent magnets are either magnetized or demagnetized.

 With this method of controlling the magnetic system of the stand, current is supplied to the electric coils by short pulses and only at the moments of adjustment of the rolling force. In this case, the magnetic system does not heat up and for a long time can be either on or off without consuming energy from an external current source.

 When making pressure rolls in the form of permanent magnet cores, the latter are made of cast permanent magnets, for example, UNDK24 grade / iron-nickel-aluminum-cobalt alloy /, the residual induction of which is about 1.2 T.

 The proposed stand is characterized in that it uses the well-known effect of attraction and repulsion of the poles of electromagnets to create the rolling force P.

 The invention is illustrated by drawings, where in FIG. 1 is a general view of the QUARTO rolling stand; FIG. 2, a diagram of the interaction of magnetic fluxes of the main and additional U-shaped electromagnets penetrating the pressure rolls, FIG. 3 / view A / - cross section along the pressure roll.

 Rolling stand / Fig. 1 / consists of two U-shaped electromagnets consisting of magnetic circuits 1, 2, 3 and excitation coils 4 located above the rolling plane, two U-shaped electromagnets consisting of magnetic circuits 5, 6, 7 and excitation coils 8 located below the plane rolling, two flat electromagnets, consisting of a magnetic circuit - pole 9 and magnetic circuits 10 and 11 and excitation coils 12 mounted symmetrically relative to the rolling plane, covering the pressure rolls 13 and made in the form of cores of permanent magnets 14, sn bzhennyh control coils 15 and the cylindrical magnetic cores covered - adders magnetic fluxes 16, interconnecting like poles / S /.

To change the magnetic flux density Φ _{p /} 2 / along the barrel of the pressure roll 13, the cage is equipped with additional electromagnets 17 mounted on the sides of the magnetic cores 1, 7 and / or / 3, 5 with U-shaped magnetic cores. The change in flux density Φ _p occurs by creating parallel flows Φ _{p of} one or opposite directions with the direction of flow Φ _p . Flat electromagnets are installed with a gap δ _of , and U-shaped electromagnets are installed with a gap of δ _p with respect to the surface of the rolls 13. Magnetic circuits 1, 2, 3 and 5, 6, 7 are connected to each other through supports 18 of non-magnetic material with tie bolts / screws / 19. Magnetic cores 7 have tides 20 for attaching the stand to the foundation 21.

 The pressure rolls 13 and the work rolls 22 are mounted on pillows 23 freely moving along the vertical groove "P". U-shaped and flat electromagnets are rigidly connected to each other using bolts 24. The cage is attached to a non-magnetic foundation 21 using bolts 25. The roll drive is conventionally not shown. Pillows 23 are made of non-magnetic material.

Rolling mill works as follows. Since the gap S _о between the work rolls depends on the magnitude of the currents I _k in the coils 4 and 8 and I _{with the} coils 12, i.e. S _o = f / I _k , I _c / or h _k = F / I _k , I _c /, where h _k is the final thickness of the strip, then, by supplying the corresponding currents I _k and I _c to the excitation coils, they create the corresponding forces Q _p - the attraction of the rolls 13 to the poles 3 and the force Q _{from the} repulsion of the rolls 13 from the poles 1, 9. The sum of the projections of all the forces on the axis "Y" will create a rolling force P, with which the rolls 22 are pressed against each other, after which the strip is fed into rolls 22, which diverge by a value of h _to , and its rolling is carried out. The longitudinal difference in thickness is regulated by changing the magnitude of the currents I _k and I _c , and the transverse difference in thickness is regulated by currents I _d / Fig. 2 / in the control coils of the electromagnets 17, changing the magnetic flux density Ф _p along the roll barrels 13, directing the fluxes Ф _р in one or the opposite direction with respect to the flow direction Ф _п . If the flows _{f p} and _{f p} coincide in the direction / Fig. 2a /, then the electromagnetic pressure with which the rolls 13 press on the rolls 22 increases at the ends of the rolls and the strip profile is obtained in the form of “lentils”. If the flows _{f p} and _{f p} do not coincide in the direction / Fig. 2b /, the electromagnetic pressure increases towards the center of the rolls and the strip profile is obtained in the form of a biconcave lens.

The rolling force can be determined by the expression
P = 2Q _p • cos α + Q _from (1),
because Q _p = 4.06 B ² • S _p and Q _from = 4.06 B ² • S _from ,
then P = 8.12V ² • S _p • cos α + 4.06V ² • S _from (2),
where S _p the contact area of the poles 3 and 5 with the surface of the rolls 13, cm ² ;
α is the angle between the force of attraction of the roll to the pole and the rolling force P, rad .;
S _from - the area of repulsion of the roll from the pole, cm ² ;
B - magnetic induction in the gaps δ _p and δ _from , T _l ;
S _p ≈ 0.2 π d _n • L _n ; S _from ≈ 0.45 π d _n • L _n . (3)
Given the expressions / 1 / - / 3 / we get:
P ≈ 1.8 π d _n • L _n • B ² • / 0.9 cos α + 1 /, kgf, (4)
where d _n is the diameter of the pressure roll, cm;
L _n - the length of the barrel of the pressure roll, see

 This invention allows to reduce the number of defects "wave", "box", to reduce the longitudinal and transverse different thickness of the strip, to increase the resistance of the rolls, to improve the quality of finished products.

Example. Given: d _n = 200 cm, L _n = 200 cm
B = 2 T, α = 30 ^o
Then according to (4) we get:
P = 1.8 • 3.14 • 200 • 200 • 2 ² • (0.9 • 0.86 + 1) = 1609689.6 kgf = ≅ 1610 tf. = 16.1 plural

Claims (1)

 A rolling stand comprising a bed, rolls, roll drive, magnetic cores, coils and an electric current source, characterized in that it is provided with at least one pair of U-shaped electromagnets, one pair of flat electromagnets with a rectangular core, covering the rolls and arranged in relation to each other to each other with the same poles relative to the rolling plane, the stand frame is aligned with the magnetic cores, the pressure rolls are made in the form of permanent magnet cores equipped with control and coverage coils nnyh cylindrical magnetic cores, the interconnecting like poles on the sides of the U-shaped electromagnets installed additional U-shaped electromagnets equipped with control coils, U-shaped electromagnets are rigidly interconnected by a nonmagnetic nonmagnetic supports and stand foundation using screws.

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