Calibration of rolls for reducing rolling mill

 

(57) Abstract:

The invention relates to the calibration of rolls for sets of rolls, each consisting of three rolls mnogoluchevogo reducing rolling mill, operating without the use of mandrels. To improve the calibration of the rolls and provide for the material in the pipe such local effects, so that the reduced local thickening of the wall of the pipe when the reduction in critical seats around the perimeter of the pipe, according to the invention it is proposed that the size of (a) convexity (5) on the sides (4) caliber at least several sets of rolls arranged one behind the other in the direction of rolling, increased at constant or the same percentage value. The invention provides a reduction in local thickening of the wall of the pipe when the reduction in critical locations along its perimeter. 3 C.p. f-crystals, 2 Il.

The invention relates to the calibration of rolls for sets of rolls, each of which consists of three rolls, mnogoluchevogo reducing rolling mill, operating without the use of a mandrel in which the concave contours of caliber rolls have bumps on both sides of the caliber of every who's mills, operating without an internal tool, when rolling occurs a phenomenon associated with the formation of polygonal or polygonal in shape. The internal diameter of the pipe has a shape differing from a circular cross-section, which is possible by the use of two gauge rolls described as rectangular, and the application of the three calibers rolls - like hexagonal shape in cross section with rounded edges.

To prevent this, the so-called polygonal shape inside the pipe, made various suggestions, which lead mainly to unsatisfactory results or costly.

The proposal is appropriate in this plan, is described in German patent DE 24 48 158. Based on the fact that the magnitude of the manifestations of internal diversity the less, the more sets of rolls used in the reduction rolling mill, the prior art proposes to bring the conditions of compression set, formed by three rollers, to the conditions of the compression set of rolls formed six rolls. To this end, the contours of caliber rolls pre-make convex on the sides of the rolls.

The proposal Sombra does not determine the state compression. Therefore, in the known solution the effect of the form of the caliber mistakenly associated with the passage of the material during rolling in the pipe occurs unfavorable, stress state and, as a result, the finished pipe along its perimeter appear thickened.

The purpose of the invention under examination, based on the descriptions to the German patent DE 24 48 158 and suggested there forms caliber, is to improve the calibration of rolls for reducing rolling mill in such a way as to exert a local effect on the course material in the pipe, so that the reduced local thickening of the wall of the pipe when the reduction in critical seats around the perimeter of the pipe and to avoid on the finished pipe is thickened places.

To solve this task according to the invention it is proposed that in the famous running of the contour gauge the size of the bulges on the sides of the caliber in sets of rolls, one after the other in the direction of rolling, increased in size, constant or the same in percentage terms. The basis of this proposal is supposed that the well-known convexity does not affect the flow of material, if not in each stand a certain number of workers clne, than at the base caliber or ledge caliber. As a consequence, the height of the protrusion should be increased from crate to crate series gauges. With the help of the invention is obtained the advantage that the local convexity increases the local contact pressure at each stand, which prevents the thickening of the material in the middle of the side of the gauge. In the case of polygonal form, i.e. without the use of the invention, the finished pipe these places are increased wall thickness relative to the rest of the pipe perimeter. The proposed features of the invention counteract this thickening.

According to the most favorable variant implementation of the invention increase the convexity is from 1 to 5% of the wall thickness rolled in the caliber of the pipe.

In another form of execution of the invention it is suggested to place the top point of the convexity of each side of the gauge, if the count from the base of the gauge with respect to the middle point of the caliber of the set of rolls is shifted to 30-35 in the direction of the lip rolls. Due to this event is prevented that the flow of material through the bulge, located in the middle or offset to the base caliber, on the highest point of the convexity according to the proposals, according to the invention is shifted in the direction of protrusion of the caliber, that is, the bulge is located asymmetrically on the side of the gauge, this harmful effect is compensated.

Turned out to be advantageous if according to another additional characteristic of the invention, the total number of stands with bulges on the sides of the caliber of work stands following the draft tube stands, the maximum is 12. Due to the characteristics of the present invention, in particular, when the reducing stretch-reducing rolling of steel pipes is possible largely to avoid getting internal polygonal shape, due to the fact that the course material in the pipe is desired impact. In the result, you can expect uniform crimping during rolling, mostly without internal diversity, i.e. to carry out rolling with a uniform wall thickness around the perimeter.

On a very simplistic drawing shows the invention, which is explained in more detail below.

In Fig. 1 shows the outline of the caliber of one of the three rolls of the set of rolls,

Fig. 2 - the chart value of convexity depending on the place the cage (in a range of calibers).

In Fig. 1 position 1 shows part of a set of rolls, the basis is from the main body 2 of the caliber and the decision of the German patent DE 24 48 158, both side zones 4 of the main part 2 of the caliber lying next to the base 3 caliber, have a convexity, and the size of the bumps 5 are marked "a". The top 6 of each convexity 5 lies at an angle relative to the Central point 7 gauge, measured from the base of the 3 calibers, and is 30-35o.

With reference to Fig. 2 the value of "a" convexity increases by a constant or a percentage equal size, starting from where i stand, to the next adjacent stands i+1, i+2, i+3, i+4, and so on. The values of i - (i+n) indicates the location of the cage in the total number of working stands, of which a maximum of 12 expediently provided with a value of convexity 5, increasing in accordance with the invention.

1. Calibration of rolls for reducing rolling mill, containing sets of rolls, each of which consists of three rolls during operation without the use of a mandrel in which the concave contours of caliber rolls have bumps on both sides of each roll, characterized in that the size of (a) convexity (5) sides (4) caliber at least several sets of rolls, one after the other in the direction of rolling is increased by a constant or the same as a percentage of the 1 - 5% of the total wall thickness of the pipes to be rolling in the caliber.

3. Calibration rolls under item 1 or 2, characterized in that the upper point (6) of the protuberances (5) on each side (4) caliber, ranging from the base (3) caliber, and midpoint (7) the caliber of the set of rolls is offset 30 - 35oin the direction of the lip (8) of the roll.

4. Calibration rolls according to any one of paragraphs. 1 to 3, characterized in that there is a conjugate of a number, equal to a maximum of 12 stands, work stands (from i to I+n), following the crimping (draft) stands, with protuberances (5) on the sides (4) caliber.

 

Same patents:

The invention relates to pipe manufacture and can be used on assemblies, imeushih composed of novokletevoj mill longitudinal besprovodnoy rolling tubes

The invention relates to rolling production and can be used in the reduction and sizing mills for the manufacture of pipes, as well as in mills for continuous rolling and wire rods

The invention relates to the manufacture of cold-reduced welded pipes and cable sheaths

The invention relates to the manufacture of welded tubular products, in particular columnarization welded pipes and cable sheaths

FIELD: automation of rolled stock production.

SUBSTANCE: at controlling thickness of tube wall in multi-stand continuous stretch-reducing mill, thickness of tube wall is measured behind mill by means of wall thickness measuring devices. Measured values are processed in computing unit. Revolution numbers of drive engines of rolls are controlled by means of units for controlling revolution number. In order to minimize formation of inner multi-arc profile at passing tube, total elongation value is kept constant due to changing revolution number of drive engines of rolls under control of computing unit.

EFFECT: enhanced quality of products.

5 cl, 4 dwg

FIELD: manufacture of sheathing determined shape by cold reduction of hollow welded blank such as tube.

SUBSTANCE: method comprises steps of feeding and placing blank onto feed roller table; orienting and matching blank relative to rolling mill; deforming hollow welded blank between rolls of several successively arranged stands at simultaneously reducing blank along its perimeter and creating longitudinal tension drawing effort; finally working blank in multi-roll pass according to size of ready of product. Hollow welded blank is deformed while perimeter and thickness of its wall are hold constant during the whole manufacturing cycle beginning from guiding welded blank till discharge of ready product for several successive transitions. Strict order of said transitions is determined by creation of deformation zones at optimized stress-deformed state of metal and by deformation intensity between stands of rolling mill. Accuracy for keeping constant values of wall thickness and perimeter of initial welded tubular blank is controlled due to calibration of rolls in such a way that to act locally upon metal flowing in tube in critical points along perimeter. Reduction is realized due to preliminarily reducing tube along its contour for shaping ribs; further reducing blank for forming two basic surfaces of the most simple geometry and preliminarily forming two remaining basic complex-geometry surfaces. Then said two remained basic complex-geometry surfaces are finally reduced. Triangle bending portion is rolled and grooves are formed in vertical end strut and supporting platform. Triangle bending portion is additionally rolled and geometry parameters of shape that are important for operation are finally sized with possibility of compensation of errors of shape members with free dimensions. Then ready shape is straightened. Reduction is performed at similar angular velocity of rolls in all stands and slip is provided in zones of velocity error. Procedures of preliminary reduction of tube along its contour for forming ribs, further reduction of blank for forming two basic simple-geometry surfaces, preliminary forming of two remaining basic complex-geometry surfaces, further reduction for finally forming two complex-geometry basic surfaces, rolling triangle bending portion and forming grooves in vertical end strut and in supporting platform are performed in double-roll stands. Additional rolling of triangle bending portion, final calibration and straightening of ready shape are performed in multi-roll stands. Welded tubular blank is oriented in feed roller table in such a way that welded seam is in lower flange of shape that is parallel to supporting platform. The whole manufacturing process is realized in the same line. Invention provides possibility for acting upon stress-deformed state of metal in deformation zone for producing sheathing preset-contour shape from widely used in industry welded tube blank with diameter 114 mm and wall thickness 3 mm during optimized technological mode concerning metal state and deformation intensity.

EFFECT: enhanced accuracy of geometry size, lowered energy consumption for making shape.

5 cl, 5 dwg, 1 ex

FIELD: technological sizing tool for reduction tube rolling mill.

SUBSTANCE: sizing tool includes several successively arranged two-roll reducing shaping roll grooved passes and multi-roll passes for final sizing and straightening of ready product. Said shaping roll grooved passes are arranged according to strict order without angular shift of their parting planes. Profile of cross section of shaping rolls of each next pass is formed by recesses and protrusions with curvilinear and (or) rectilinear surfaces with possibility of proportional geometrical approach to shape of ready product. It is achieved due to satisfying condition of equal values of summed perimeter of grooved rolls of each stand and outer perimeter of initial blank. Profile of finish roll grooved passes is identical to outer contour of ready product and it is possible to adjust it in admissible range while using sixteen reduction shaping stands and four finish passes. According to invention it is possible to act upon stress- deformed state of metal in deformation zone for making preset-contour section of widely used in industry welded tube 114 x 3 mm in manufacturing mode optimal from view point of metal state, deformation intensity and comfortable condition of tool operation.

EFFECT: simplified design and manufacturing process of rolls, improved accuracy of products, lowered energy consumption.

2 cl, 5 dwg

FIELD: rolled tube production, namely manufacture of sheathing determined-contour section by cold reducing of hollow welded blank.

SUBSTANCE: reducing mill for cold reduction of sheathing determined section of hollow welded blank such as tube includes accumulator, inlet roller table, housing supporting successively arranged stands, technological sizing tool. Knocking out roller table, drive unit of mill and control panel. Technological sizing tool includes row of two-roll shaping roll grooved passes mounted in housing without shift of their parting planes and arranged one after another. It allows form by initial reduction in first stands shaping ribs of section; by further reducing simple-geometry basic surfaces, basic surfaces with more complex shape, rolling triangular bent portions and forming grooves on vertical end strut and on supporting site. Parting planes of all two-roll passes are arranged in the same plane. Summed (for two rolls of each stand) perimeter of cross sections of roll passes while taking into account protrusions, recesses with rectilinear and (or) curvilinear surfaces is equal to perimeter of initial hollow welded blank. Mill also includes sets of non-driven rollers whose rotation axes are normal to rotation axes of rolls. Said non-driven rollers are mounted between first shaping stands. Multi-roll roll grooved passes are used for finally sizing and straightening ready product with possibility of compensating admissible fluctuations of hollow welded blank. Drive unit is in the form of separate kinematic circuits with individual sources of torque for providing constant revolution number of rolls in all stands. Diameter of roll grooved passes are calculated according to condition of constant drawing speed of section through all stands and similar cross section areas of each intermediate section and initial blank. Invention provides possibility for acting upon stress-deformed state of metal in deformation zone for producing sheathing preset-contour section of widely used in industry welded tube 114 x 3 mm in manufacturing mode optimal from view point of metal state, deformation intensity and comfortable condition of tool operation.

EFFECT: simplified design and adjustment of mill, enhanced accuracy of products, lowered energy consumption.

5 dwg

FIELD: tube production, namely operation method of stretch-reducing mill for rolling finite-length tubes.

SUBSTANCE: rolling mill includes at least two rolling stands arranged one after another along tube feed direction. Each rolling stand includes at least two mutually engaged rolls. Each roll rolls tube along predetermined peripheral zone of tube. Rolls of two different stands are driven by means at least of two drive units for enhancing quality of successive processes. Method comprises steps of determining time moment when rear end (along feed direction) of tube leaves last outlet rolling stand; setting time interval of predetermined duration including time moment when rear end of tube leaves outlet rolling stand; controlling drive unit of outlet rolling stand in such a way that to lower at said time interval revolution number of rolls of outlet rolling stand and to provide tube discharging at stable speed. Invention provides uniform motion of tube for achieving desired accuracy of process.

EFFECT: elimination of acceleration of tube at outlet of last rolling stand.

11 cl, 5 dwg

FIELD: three-roll rolling stand, possibly finish stands of sizing and reducing mills where roll load is slightly less than in rough rolling stands, calibrating mills.

SUBSTANCE: three-roll working stand for lengthwise rolling with adjustable roll gap and with one inlet shaft includes housing where three roll units mutually joined through cone gear wheels not changing their position during roll gap adjustment are mounted. Simultaneous adjustment of all rolls is realized due to rotation of eccentric sleeves by means of their rotation drive mechanism. Each cone gear wheel is mounted in housing of stand in rolling bearing assemblies. Drive shafts of rolls are hollow ones and they are provided with internal teeth.

EFFECT: improved operational efficiency of stand, simplified adjustment of roll gap.

2 cl, 4 dwg

FIELD: technological processes.

SUBSTANCE: invention may be used for production of encasing steel profiles from welded tubular billets by method of cold sink drawing-down. Mill contains accumulator, supply roller bed, plate with cages installed in it one after another, roller bed-kicker, mill drive and control panel. Every cage is equipped with stands that are connected by means of ties and fixed at rolling mill plate. Every stand is equipped with vertical rectangular groove on front surface and T-shaped grooves at side ends. Mill is equipped with additional hinged vertical cages with molding rollers, one of which has the possibility of centre-to-centre distance regulation between them. Hinged cages are installed with the possibility of position regulation in respect to profiling axis in vertical and horizontal directions.

EFFECT: simplification of design and mill adjustment; expansion of mill technological resources at the account of additional elements application; higher article accuracy and reduction of power inputs.

2 cl, 5 dwg

FIELD: technological processes.

SUBSTANCE: invention may be used for production of encasing steel profiles from welded tubular billets by method of cold sink drawing-down. Method includes deformation of hollow billet in rollers of cages and creation of longitudinal pulling force at identical speeds of rollers' rotation in all cages until profile with required dimensions is obtained. Deforming is carried out by anti-crossbreaks with preservation of perimeter without account of billet thickness and further calibration of profile. Formation of sections that are hard-to-reach for technological tool is performed by their exposure to neighbouring active parts, which are subjected to rollers effect. Angles of bent end during deformation of profile elements are selected based on condition of equality of ratio of bent end angles values for smoothly deformed sections and for intensively deformed sections 3-5. Directions of deformations are selected so that centres of masses of sequentially produced profile during billet displacement from cage to cage are located along single straight line that matches rolled metal axis.

EFFECT: invention allows to expand technological resources of rolling mill; to increase quality of articles; to simplify design and reduce mill material intensity and power inputs.

2 cl, 4 dwg

FIELD: transportation.

SUBSTANCE: technological calibration tool includes series of several forming pinch passes and final calibration and trimming passes for finished product. Roll passes for final calibration are compound to enable relative rotation of working roll surfaces forming profile areas and removed from roll rotation axis at different distance. Just one element out of roll components is guiding, and guided elements of compound rolls feature bearings.

EFFECT: reduced power consumption of mill; improved article quality and precision and enhanced life time of tool.

2 cl, 1 dwg

FIELD: metallurgy.

SUBSTANCE: it is implemented delivery of blank to supply roller bed and its straining at several stages in rollers of several placed stands with keeping of perimetre and thickness of wall. Preliminarily it is cogged blank by contour for receiving of ribs, following reduction there are received two locating reference points in multirolled stands, it is finished by following reduction forming of two rest locating reference points of irregular shape. It is implemented rolling of flap of triangular shape and there are received grooving on vertical butt post and joggle. It is implemented final rolling of flap of triangular shape and final calibration of geometrics in stands with different angular velocity of calibrating elements of rollers with usage of rolling friction on effective area of rollers elements in places of maximal disparity of its angular velocities.

EFFECT: it is reduced rollers wear, increased its durability, and also increases accuracy of manufacturing of contour form profile from hollow welded blank of round shape.

4 cl, 5 dwg, 1 ex

Up!