Feeding mechanism of pilger mill

FIELD: machine building.

SUBSTANCE: workpiece feeding mechanism in a pilger mill comprises a casing (1), an air chamber (2) with an air piston (3), a piston (4), a water chamber (5) with a hydraulic piston (6) fitted by longitudinal shank ends (7) and (8). The hydraulic piston 6 is installed with an annular gap in relation to the internal surface of a cushion boss (9). A rod (4) is coupled with the air piston (3) on one side and with a mandrel head (12) on the other side. The hydraulic piston is fitted by longitudinal shank ends, in its extreme positions they extend beyond the water chamber (5) by the value being by 5% of its stroke less, the hydraulic piston is made as a bush and can freely move along the rod.

EFFECT: reduced dimensions of the feeding mechanism and higher reliability of its operation.

1 dwg

 

The invention relates to the processing of metals by pressure, namely to devices for moving the workpiece during its filing on rolling in piligrimages the camp.

Known feed device piligrimage mill (49-00.00 SAT, Chelyabinsk tube rolling plant OJSC CHTPZ TPZ-1), comprising a housing having disposed therein a cylinder and a brake device, made in the form of a set of Belleville springs, and the inside of the housing with the possibility of reciprocating movement is set rod connected to one side of the piston of the pneumatic cylinder and on the other hand - with the bezdornovoy head.

A disadvantage of the known feed device is the low resistance to high force loads on the spring brake devices that quickly become useless and cease to balance the forces of inertia as a cushioning device. This causes a large shock load from the piston to the front end of the pneumatic cylinder, causing its deterioration and the destruction of springs and the front cover of the braking device and, as a consequence, the need for repairs of the feeding apparatus.

The closest in technical essence is a feed device (mechanism) piligrimage mill (U. F. Sawakin, Kolikov V. P., and Yu. Raikov. The production of pipes. Moscow: Intermet Engineering, 2005. Feed device hydraulic�them braking p. 175, Fig.7.), including air chamber with located in it, air piston, and the water chamber with a hydraulic piston and a rod passing through an air and water chamber and connected on one side with an air piston, on the other hand - with the bezdornovoy head.

Known feed mechanism is more reliable in operation as compared with the above analogue. However, the presence of long water camera determines greater length of the stem, which increases the moving mass, and hence dynamic loads. It is not excluded certain deformation of the long rod, which causes the edge contact of the air piston with the wall of the air chamber. This, in turn, causes local destruction of the piston, which reduces the reliability of his work. In addition, in the known feed mechanism is not guaranteed simultaneous touch pneumatic and hydraulic pistons of the front walls of the pneumatic and hydraulic chambers, which does not preclude strong impacts or the other of the piston on the front wall of the corresponding chamber, causing rapid deceleration of the feed mechanism, which can disrupt the contact of the pipe with the mandrel.

The technical result is to reduce the size of the feed mechanism and improving the reliability of its work.

Said technical result is achieved in that in podushe� mechanism piligrimage mill, comprising a housing having disposed therein an air chamber with an air piston, a water chamber with a hydraulic piston, and a rod passing through an air and water chamber and connected to one side of the air piston, on the other hand with the bezdornovoy head according to the invention the hydraulic piston is provided with longitudinal shafts, exposed in the extreme positions of the hydraulic piston outside of the water chamber at a value less than 5% of the stroke of the hydraulic piston, the hydraulic piston is made in the form of a sleeve and is mounted on the rod with the possibility of free movement along it.

Performing hydraulic piston shafts, exposed in its extreme positions outside of the water chamber, allows in 1, 3 times to reduce the length of the rod, which reduces the moving mass and dynamic load device, and also increases longitudinal stability.

Protrusion of the shank in the end positions of the hydraulic piston outside of the water chamber at a value less than 5% of the stroke of the hydraulic piston, prevents simultaneous touch of air and hydraulic pistons of the front walls, respectively, pneumatic and water chambers due to the fact that when the piston rod air piston forward first touch surfacing and good hand feeling� air piston rear longitudinal shank hydraulic piston. Then there is the movement of a hydraulic piston, while in the period of one cycle of operation of the feed mechanism of the hydraulic piston, not reaching the front cover of the water chamber on the magnitude of 5%, due to the pressure of the remaining compressed fluid eliminates the hard hitting of a pneumatic piston on the front wall of the pneumatic chamber. This significantly increases the reliability of the pistons and, in General, the feed mechanism. The reduction of stroke of the hydraulic piston to a value less than 5%, does not guarantee sufficient mitigation of the impact of a pneumatic piston on the front wall of the chamber. The reduction of stroke of the hydraulic piston by an amount larger by 5%, does not provide the necessary reduce the final speed of the rod with the bezdornovoy head and thereby worsens the conditions of braking.

Technical solutions, which coincides with the set of essential features of the invention, not identified that allows to make a conclusion about its compliance with the patentability of "novelty."

The essential features of the claimed invention, determining the receipt of the indicated technical result that is explicitly not follow from the prior art, which allows to make a conclusion about conformity of the invention the condition of patentability "inventive step".

The condition of patentability "industrial applicability" is confirmed on the prima�e of embodiment of the invention.

The drawing shows the feed mechanism piligrimage mill.

Feeder piligrimage mill includes a housing 1, air chamber 2 with the air in it a piston 3 connected with the rod 4, the water chamber 5 with the hydraulic piston 6, is provided with a shank 7 and 8. In the housing 1 set of brake bushing 9 and the front cover 10 and the regulating valve 11. The front shank 7 is hermetically sealed relative to the cover 10 and the rear shank 8 - relative to the rear wall of the water chamber 5. The outer surface of the piston 6 is located with a gap relative to the inner surface of the braking sleeve 9. The piston 6 is made in the form of a sleeve and is mounted for free movement relative to the rod 4. The rod 4 passes through the air chamber 2 and the water chamber 5 and is connected to one side of the air piston 3, on the other hand - with the bezdornovoy head 12.

Feeder piligrimage mill operates as follows. After another feed during rolling of pipe blanks in a production crate piligrimage mill (not shown), the workpiece together with the bezdornovoy head 12, the piston rod 4 and the air piston 3 moves back toward the air chamber 2, clenching in the air. After moving the rod a distance equal to the length difference of the air 2 and water 5 cameras, Dornava head 12 enters �ontact with front shank 7, protruding beyond the cover 10, and simultaneously moves the hydraulic 6 and air 3 pistons by an amount corresponding to the stroke length of the hydraulic piston 6 in the water chamber 5. The rear shaft 8 protrudes into the cavity of the air chamber 2 by the length of stroke of the hydraulic piston 6 in the water chamber 5. At the end of the stroke of the rod 4 is in its rearmost position, thanks to the release of tubular workpieces from the interaction with the rolling tool (not shown), Dornava head together with the rod moves rapidly forward under the action of compressed air pressure on the air piston 3. Air piston 3, approaching the rear of the shank 8 of a hydraulic piston 6 reaches its maximum speed of translational motion and in contact with the shank 8, protruding to the air chamber 2, moves the hydraulic piston 6 in its extreme forward position. During this period, due to the deceleration of the air piston 3 due to the additional resistance of water flowing through the narrow annular gap between the outer surface of the hydraulic piston 6 and the inner surface of the braking sleeve 9, which protects the feeder from shock loads. During this period, joint slow motion air 3 and 6 hydraulic pistons is accompanied by a drop in speed of the rod with the bezdornovoy head. Advanced�tive braking air piston and prevent hitting it on the front wall of the air chamber 2 is provided by the pressure remaining of the compressed fluid between the front wall 10 and a hydraulic piston 6 when reducing 5% of the value of his course. In operation, the feed mechanism additional control of the pressure in the water chamber 5 is carried out by adjusting a valve 11.

Thus, the proposed design of the feed mechanism can significantly reduce the length of the stock shock that increases the reliability of the feeder.

Feeder piligrimage mill comprising a housing having disposed therein an air chamber with an air piston, a water chamber with a hydraulic piston, and a rod passing through an air and water chamber and connected to one side of the air piston, and on the other hand - with the bezdornovoy head, characterized in that the hydraulic piston is provided with longitudinal shafts, exposed in the extreme positions of the hydraulic piston outside of the water chamber at a value less than 5% of the value of its stroke, when the hydraulic piston is made in the form of a sleeve and is mounted on the rod with the possibility of free movement along it.



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: invention relates to pipes production, in particular to method of process pipes production of size 284×11×26100-26600 mm at pipe-forming installation 8-16" with pilger mills out of bi-metal thought high blank ingots produced by electroslag remelting process of low-ductile steel "04Х14Т5Р2Ф-Ш" with boron content from 2.0 to 3.0% to manufacture hex blank pipes with turnkey size 252.6±1.8×5.0+1.5/-1.0×4300+80/-30 mm for tight storage and transportation of the spent nuclear fuel. The method includes casting by the electroslag remelting process of the ingots with size 480×1800±25 mm out of low-ductile steel "04Х14Т5Р2Ф-Ш" with boron content from 2.0 to 3.0%, with bottom and shrinkable parts out of ductile carbon steels; their height is from 0.04 to 0.05 and from 0.13 to 0.14 respectively of total ingot height, creating during rolling of the process pipes the seed ends and pilger small heads, turning of the outside surface of the electroslag remelting ingots to remove cast defects producing blank ingots with size 465±5×1800±25 mm; in them through central hole is drilled with diameter 100±5.0 mm; they are heated to 1030-1050°C, pierced in a mill for transverse screw rolling into sleeves with size 450×out.295×3080-3140 mm with swaging as per diameter Δ from 2.2 to 4.3% and drawing µp from 1.69 to 1.77, sleeves are rolled in the pilger mill in process pipe stocks with size 284×11×26100-26600 mm with drawing µsr = 9.61 and swaging as per diameter Δ = 36.2%; from pipes using hot cutting saw the process wastes are cut off, providing pipe ends out of ductile carbon steels with length 600-700 mm, from stub and pilger head side the pipe stocks by the hot cut saw are cut to pipes having multiple length and residue, multiple length pipes and residue are straightened in the six roller machine using the rolling heating temperature, at that the first multiple length pipe and residue are fed to the straightener by ends out of ductile carbon steels, the first multiple length pipe is cut in the machine from side of the carbon steel with length 5300±50 mm and residue, the second multiple length pipe is cut to two pipes with equal length, are bored and turned to the cylindrical blank pipes with size 278.5±1.8×5.0+1.5/-1.0 mm for profiling in hex blank pipes of specified size, sleeves are rolled in the process pipe stocks with size 284×11 mm in gauge 290 mm in mandrel bars with diameter 264/265 mm heated to 500-550°C by rolling of setting carbon sleeves as per the following process: mandrel bar is inserted in the sleeve, front carbon end is rolled with increasing of the sleeve feeding to the deformation area m from 0 to 18 mm, steel "04Х14Т5Р2Ф-Ш" sleeve is rolled under stable process with feed m = 12-14 mm, and rare carbon end, as well as pilger head are rolled with feed m = 18-20 mm. Production of process pipes with size 284×11 mm out of steel "04Х14Т5Р2Ф-Ш" with boron content from 2.0 to 3.0% is ensured to manufacture hex blank turnkey pipes 252.6±1.8×5.0+1.5/-1.0×4300+80/-30 mm for tight storage and transportation of the spent nuclear fuel.

EFFECT: reduced metal consumption, reduced weight of hex blank pipes and racks weight upon simultaneous increased capacity and reliability.

2 cl, 1 tbl

FIELD: technological processes.

SUBSTANCE: invention relates to metallurgical and pipe rolling industries. Electroslag melting bars with size off 485×1600±25 mm are cast and turned into cakes with size of 470×1600±25 mm. A through hole is drilled with a diameter of 100±5 mm. Cakes are heated to temperature of 1120-1140°C and pierced in a cross-rolling mill into blooms with size of 480×vn.315×2500 mm. Cakes are rolled into pig hot-deformed stock pipes with size of 337×28×8000 mm in a gauge 340 mm on burnishers 282/286 mm with drawing of µn=3.79, clamping by diameter Δ=29.8% and feed of blooms into a deformation site m=16-18 mm. Stock pipes are straightened using temperature of rolling heating and cut into two stock pipes with size of 337×28×4000 mm. Stock pipes are turned and ground. Rolling of stock pipes on cold pilgering mills 450 and 250 is carried out along the routes: 325×12×4000---273×8×6680---219×4×16100 mm. Pipes are cut and rolled on the cold pilgering mill 250 into stock pipes with size of 194×2.5×14100 mm. At one of ends of stock pipes they drill a hole for a pivot of a pulling chain. Stock pipes are profiled into hexahedral pipes with a flat-to-flat dimension of 175±0.4×2.5+0.3/-0.2×14100 mm.

EFFECT: reduced discharge coefficient of metal.

FIELD: technological processes.

SUBSTANCE: invention relates to rolling. Hollow bars are cast by electroslag melting from low plastic steel "04Х14Т5Р2Ф-Ш" with boron content from 2.0 to 3.0% with size of 470±5×vn.270±5×3000±50 mm. They are ground and turned into hollow blooms with size of 455±5×vn.280±5×3000±50 mm. Heated to temperature of 1040-1060°C. Rolled into pig pipe stocks with size of 287×11×25600-29600 mm on burnishers 266/267 with drawing µ from 9.69 to 10.86 and clamping by diameter Δ from 33.5 to 39.1%. Pipe stalks are cut with a hot saw into multiple-length pipes of 10200±50, 11500±100 mm and straightened. Multiple-length pipes are cut into two stock arms with length of at least 5000 mm. They are ground and turned into stock pipes with size of 280.8±2.0×5+1.5/-1.0 mm and profiled into hexahedral pipes of the specified size.

EFFECT: invention provides for reduced metal consumption.

5 cl

FIELD: technological processes.

SUBSTANCE: invention relates to pipe rolling Cakes with size of 620×100×1750±50 mm are heated to temperature of 1260-1270°C and are pierced in a cross-rolling mill into bloom stocks with size of 620×vn.265×1985-2105 mm on a holder with diameter of 250 mm true to size along external diameter and drawing µ=1.17. Blooms are heated from cold or hot charging to temperature of 1260-1270°C and pierced - rolled true to size along the outer diameter into blooms with size of 620×vn.390×2630-2800 mm on the holder with diameter of 375 mm with drawing µ=1.33. Blooms are rolled on a TPU 8-16" with Pilger rolling mills into stock hot-rolled pipes with size 480×58×5500-5800 mm with clamping by diameter Δ=21.8% and drawing µ=2.37. Pipes are turned and bored into pig mechanically treated pipes with size of 470×47×5500-5800 mm with removal of metal on the outer surface at ≤5.0 mm, and along the inner surface at ≤6.0 mm, and roll them into pig hot-rolled mechanically treated pipes with size of 470×47×5500-5800 mm on a cold-pilgering mill 450 into commercial cold-rolled pipes with size of vn.346×40×6700-7200 mm with drawing µ=1.29 and clamping along diameter Δ=9.36%, roughness of internal and external surfaces Ra of not more than 2.5 mcm.

EFFECT: invention provides for reduced metal consumption.

1 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. ESR ingots are cast and turned to ingots-billets of 470×1540 mm. Through central 100±5 mm-dia bore is drilled therein. Blanks are heated to ductility temperature and pierced at screw rolling stand to sleeves-blanks. The latter are rolled to hot-formed rerolled pipe billets. Said pipes are straightened and cut to two billets. The latter are bored and turned. Pipe billets of 325×12 mm are rolled at "ХПТ450" and "ХПТ250" mills while pipes-billets are rolled at "ХПТ250" mill. Pipes are shaped at shaping Mill-400 to hexagon pipes-billets.

EFFECT: decreased metal consumption factor.

1 tbl

FIELD: metallurgy.

SUBSTANCE: invention relates to a manufacturing method of cold-rolled marketable pipes with the size of 170±1.5×3±0.25×370 mm with increased accuracy as to the wall from steel grade '16Х12МВСФБР-Ш' for fast neutron reactors of a new generation. ESR ingots are cast as hollow ones with the size of 490×in290×3000±25 mm, turned into hollow cakes with the size of 480×in300×3000±25 mm, heated to the temperature of 1130-1150°C, rolled on pilger mills using backing carbon-bearing rings into semi-finished hot-deformed pipes with the size of 338×25×11800±100 mm, pipes are straightened in a six-roll straightening machine, cut into two pipe workpieces with the size of 338×25×5900±25 mm, bored and turned into pipe workpieces with the size of 325×12×5900±25 mm, rerolled on ХПТ450 and ХПТ250 mills along routes - 325×12×5900±25 - 273×8×10000±40 - 219×5×19400±80 mm, pipes with the size of 219×5×19400±80 mm are cut into three pipe workpieces with the size of 219×5×6465±25 mm and rolled on ХПТ250 mill into marketable pipes with the size of 170×3×13400±50 mm, then, they are cut into three marketable pipes of equal length with the size of 170×3×4465±15 mm, which are cut into marketable pipe workpieces with the size of 170±1.5×3±0.25×370 mm or accepted as equal with the size of 170×1.5×3±0.25×4440 mm.

EFFECT: reducing metal consumption at hollow ESR ingot - semi-finished hot-rolled pipe workpiece processing.

2 cl, 1 tbl

FIELD: metallurgy.

SUBSTANCE: central hole is drilled in billets, and they are heated by 20-30°C below upper limit of ductility temperature of this steel grade. Billets are pierced in the mill for transverse screw rolling into true-sized shells or with a rise as to diameter of ≤9.0%. Rolled on pilger mills into pipes. End crops of continuously cast billets with a shrinkage hole are used as billets. Length of end crops is determined from the following expression: Le.c.=L3.in, where L3.i - length of a billet for rolling of pipes of i size, mm; n - numbers of billets, pcs. Diameter of the central hole is determined from the following expression: Dc.=Ds.h.+Δ, where Ds.h. - maximum diameter of the shrinkage hole in the billet, mm; Δ=35-40 - deviation of the shrinkage hole from the centre of the billet, mm.

EFFECT: increasing steel yield on a continuous pouring unit.

1 tbl

FIELD: metallurgy.

SUBSTANCE: in cone-shaped crop-end ingots with dimensions of 600/615×100×1500 with the head removed by a flame method or by electromachining, a through central hole with diameter of 100±5 mm is drilled. Ingots are heated to ductility temperature and pierced in a mill for transverse screw rolling on a mandrel with a diameter of 500 mm into shells with diameter of 670xin515×2850 mm with an average rise as to diameter of up to 10.3%, and throughout length of the cone-shaped ingot of 8.9 to 11.7%. Shells are rolled on the pilger mill into pipes with the size of 508×11.1×20500±250, 508×12.7×18500±250 and 506×16.1×13500±250 mm. Pipes with the size of 508×11.1×20500±250 and 508×12.7×18500±250 mm are cut with a hot cutting saw into two equal parts. Rolling of casing pipes on the pilger mill is performed at rotation speed of working rolls of 32-36 revolutions per minute.

EFFECT: increasing capacity of a unit; excluding double heating and reducing metal consumption coefficient.

FIELD: metallurgy.

SUBSTANCE: method involves casting by electroslag remelting of hollow ingots from low-ductility steel "04Х14Т5Р2Ф-Ш" with boron content of 2.0 to 3.0% with the dimension of 470±5×inner270±5×3000±25 mm. Bottom and shrinkage parts of ingots with height of 0.06-0.07 and 0.08-0.10 respectively of total height of ingots are cast from ductile carbon-bearing grades and form seed ends and pilger heads at rolling of semi-finished pipes. Hollow ingots are turned and bored into hollow cakes with the dimension of 455±5×inner280±5×3000±25 mm, heated to the temperature of 1030-1050°C and rolled into semi-finished pipe lengths on mandrels 263/264 with drawing µ of 9.79 to 10.98 and swaging as to diameter Δ of 36.8 to 38.3%. Pilger heads and seed ends are removed, cut into pipes of multiple length, and then, into two shells of equal length of at least 5000 mm. Shells of equal length are turned and bored into pipe shells with the dimensions of 278.7±1.8×5+1.5/-1.0 mm and shaped into hexagonal pipes with the flat-to-flat dimensions of 252.6±1.8×1.5/-1.0×4300+80/-30 mm.

EFFECT: reduction of consumption of "04Х14Т5Р2Ф-Ш" steel.

5 cl, 1 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to pipe rolling. Proposed process comprises casting of hollow ESR 470×110×2700 and 430×105×2700 mm ingots, boring and turning them to 460×100×2700 mm and 420×95×2700 mm ingots-billets. The latter are heated to ductility temperature and rolled at 234/239mm- and 199/204mm-tapered mandrels to rerolled 325×45×6400 and 260×30×8000 mm hot-rolled pipes. The latter are bored and turned to pipes-billets 310×30×3200 and 245×16×4000 mm in size. Pipe billets are rolled at cold-rolling mills to cold-formed 168.3×10.6×5000-1000 mm tubings in 310×30-273×23-219×16-168.3×10.6 mm sections with relative wall reduction δ1m=23.3%, δ2m=30% and δ3m=33.8% and 245×16-219×13-168.3×10.6 mm with relative wall reduction of δ1m=12.8% and δ2m=18.5%.

EFFECT: lower metal input.

1 tbl

FIELD: rolled tube production, namely processes for piercing ingots and billets for making seamless hot-deformed large-diameter tubes.

SUBSTANCE: method comprises steps of heating ingots and billets until yielding temperature; piercing them to hollow thick-wall sleeves in first skew rolling mill for further expanding to thin-wall sleeves in second skew rolling mill and rolling to large-diameter tubes in plants provided with automatic or pilger mills; piercing ingots and billets to thick-wall sleeves in first piercing mill with working rolls driven to rotation in one side and expanding billets to thin-wall sleeves in second piercing mill with working rolls driven to rotation in opposite side.

EFFECT: enhanced geometry of tubes, lowered metal consumption, improved efficiency of tube rolling plants.

1 tbl

FIELD: tube production processes and equipment, namely preparation of rolls of pilger mills for hot rolling of tubes.

SUBSTANCE: method comprises steps of mechanically working portion of roll in roll-turning machine tool with use of contour follower for surfacing it with overlap 5 - 10° to side of cold portion from zero point and from angle of lengthwise outlet; under-flux surfacing working portion with wear-resistant refractory steel layer having allowance for mechanical working; mechanically working rolls with use of contour follower until their ready size and grinding working surface. Mechanical working of rolling portion of roll after surfacing is performed along portion from 0.25 - 0.30 of striker length until end of angle of lengthwise outlet adjoined to polishing portion. Grinding of polishing portion and of 0.25 - 0.30 of angle of lengthwise outlet adjoined to polishing portion is realized. Mechanical working of rolling portion of roll for surfacing from zero point until 0.25 -0.30 of striker portion is performed while taking into account allowance of surfaced layer for finish working.

EFFECT: enhanced strength of rolls of pilger mills, improved accuracy of their geometry size and quality of tube surface, lowered consumption of high-cost steel wire rod.

2 cl, 1 dwg, 1 tbl

FIELD: rolled tube production processes and equipment, namely manufacture of hot deformed mean- and large-diameter tubes of corrosion resistant hard-to-form steels and alloys, possibly making tubes in tube rolling aggregates with pilger mills.

SUBSTANCE: method comprises steps of drilling electroslag-refining ingots or billets with diameter 380-500 mm; holding them on grates of furnace at temperature 500-550°C for 70-95 min depending upon diameter of blank; heating up to temperature 1120 - 1140°C at rate 1.4 - 1.5 °C/min; piercing billets for forming sleeves at revolution number of rolling rolls 25 - 40 rev/min on mandrel with diameter providing reduction degree in pilger mill no less than 25 mm; realizing first piercing of electroslag-refining ingots or billets with diameter 460-600 mm in piercing mill at elongation degree 1.2 -1.4 and at revolution number of rolling rolls 15 -25 rev/min; realizing second and next (if necessary) piercing or expanding processes at diameter fit no more than 5.0%, elongation degree 1.4 -1,75 and revolution number of rolls 25 - 50 rev/min; seasoning cold sleeves after their first piercing with diameter 460-600 mm at relation D/S = 3.0 -4.5 on grates at temperature 400-500°C for 50 - 70 min depending upon sleeve diameter and wall thickness; heating sleeves until yielding temperature 1100 - 1260°C at rate 1.6 - 1.8°C/min depending upon kind of steel; uniformly heating sleeves with temperature 600 - 800 C after piercing mill until yielding temperature 1100 - 1260°C at rate 1.7 - 2.0°C/min; before discharging sleeves out of furnace keeping them for 45 -60 min at plasticity temperature while tilting sleeves in 10-15 min by angle 180є. Process of piercing sleeves that begins from gripping ingots or billets until their complete fitting onto mandrel is realized at decreased revolution number of rolling rolls from 25 until 15 rev/min. Stable piercing process is performed is realized at 15 -20 rev/min. At outlet of sleeve revolution number of rolls is increased up to 35 -40 rev/min. Piercing (expanding) process beginning from gripping sleeve until complete fitting of it onto mandrel is realized at decreased revolution number of rolling rolls from 50 until 20 rev/min. Stable expanding process is realized 20-25 rev/min. At outlet of sleeve revolution number of rolls is increased up to 45 - 50. Tubes are rolled in pilger mill at elongation degree μ = 3.0 - 5.0. Invention provides possibility for making high quality hot deformed tubes of large and mean diameters from corrosion resistant hard-to-form steels and alloys in tube rolling aggregates with pilger mills.

EFFECT: reduced metal consumption factor at conversion of electroslag-refining ingot to hot rolled tube, lowered cost of tubes.

5 cl, 1 tbl

FIELD: drive systems of cold rolling pilger mills.

SUBSTANCE: drive system includes rolling stand that may perform reciprocation motion; at least one crank and connecting rod mechanism operated by means of drive unit and having crank arm with balancing weight at least for partially balancing inertia forces created by rolling stand; connecting rod jointly connecting rolling stand and crank arm; at least one arranged eccentrically and driven to rotation counter-balance for balancing inertia forces and (or) moments of inertia. Motion of crank and connecting rod mechanism and counter-balance is synchronized by means of gearing. At least one crank and connecting rod mechanism is provided with single counter-balance. Motion plane of balancing weight of crank and connecting rod mechanism driven to rotation coincides with motion plane of counter-balance driven to rotation. Crank and connecting rod mechanism, counter-balance and drive unit are mutually joined through gearing. Drive unit through said gearing drives shaft joined with counter-balance. Mounted on shaft pinion of said gearing through other gearing drives shaft joined with crank and connecting rod mechanism. Balancing weight or counter-balance is in the form of eccentrically arranged mass of one gear wheel of gearing.

EFFECT: lowered cost for maintaining simplified -design rolling mill, reduced investment cost.

11 cl, 10 dwg

FIELD: drive systems of rolling mills, namely of pilger cold rolling mill.

SUBSTANCE: drive system includes at least one rolling stand mounted with possibility of reciprocation motion; at least one crank and connecting rod mechanism having crank arm with balancing weight at least for partially compensating inertia forces of rolling stand; drive unit and connecting rod jointly connecting rolling stand and crank arm; at least one counter-balance mounted with possibility of eccentric rotation in order to compensate inertia forces and (or) moments of inertia. In order to provide effective compensation of inertia forces in simplified drive system, at least one counter-balance is mounted with possibility of driving it to rotation by means of autonomous drive unit isolated from drive unit of crank and connecting rod mechanism. Said autonomous drive unit of counter-balance acts in rotation direction opposite to rotation direction of crank arm. Mass values of mass of rolling stand, balancing weight, counter-balance are selected in such a way that to compensate as possible first-order components of inertia forces of rolling stand at operation of drive system. System is provided with unit for controlling or regulating autonomous drive unit depending upon angle ϕ6 and (or) revolution number of crank arm. Rotation center of counter-balance is selected in such a way that including inertia forces of rolling stand and (or) balancing weight moments of inertia of all masses of drive system are at least significantly compensated.

EFFECT: enhanced efficiency, simplified design of rolling mill.

13 cl, 1 dwg

FIELD: production of conversion tubes of low-ductility steel with boron content 1.3 - 1.8%.

SUBSTANCE: method comprises steps of drilling ingots of electroslag refining, heating them till ductility temperature, piercing in piercing mill for making sleeves; rolling sleeves in pilger mill to tube-blanks, cooling, repairing, cutting tube-blanks by two blanks, heating them up to ductility temperature, piercing-rolling in piercing mill and rolling conversion tubes in pilger mill. Ingots of electroslag refining with diameter 460 - 480 mm are drilled from their bottom end along length L = H - B, where H - height of ingot, mm; B - under-drilled part of ingot equal to 100 - 120 mm. Then ingots are soaked at temperature 450 - 500°C on grates of heating furnace without tilting for 90 - 120 min; heated till 800 - 850° C at rate 1.8 - 2.0°C/min; then heated up to ductility temperature 1050 - 1090°C at rate 2.1 - 2.2°C/min at tilting in 15 - 20 min and soaked at such temperature for 70 - 80 min at tilting by angle about 180° in 10 -15 min.

EFFECT: lowered content of waste material, improved quality of conversion tubes, reduced cost of ready product.

5 cl, 1 tbl

FIELD: rolled stock production, namely manufacture of elongated conversion large- and mean-diameter tubes of centrifugally cast hollow billets and ingots of electroslag refining of steels 08X10H20T2 and 08X10H16T2 for telescopic systems of periscopes of submarines while providing values of impact viscosity KCU more than 100 J/cm2.

SUBSTANCE: method comprises steps of producing centrifugally cast billets, heating them till ductile temperature, rolling in pilger mill to thick-wall tubes with allowance for mechanical working, subjecting tubes to heat treatment. In pilger mill conversion hot rolled tubes are rolled while taking into account 1 - 3 rerolling procedures in cold rolling mills depending upon type of billet and dimension of ready product (length, diameter, wall thickness). Conversion hot rolled tubes are rolled to intermediate and final sizes in cold rolling mills at elongation value μ = 1.2 - 1.55. Centrifugally cast hollow billets and drilled ingots of electroslag refining are soaked on grates of furnace without tilting them at 950 -1000°C for 180 - 300 min of homogenization depending upon diameter and wall thickness. Then centrifugally cast billets are uniformly heated up to 1150 -1200°C at heating rate 2.3 - 2.5° C/min at tilting in periods of 15 - 20 min at total period of heating 8 - 11 hours. Ingots of electroslag refining are heated up to 1200 -1250°C at heating rate 1.8 - 2.0°C/min while tilting them in 20 - 25 min for total heating period 9.5 - 12.5 hours. Large-size billets and ingots are heated for more long periods. Centrifugally cast hollow billets are rolled in pilger mill to hot rolled conversion tubes while taking into account 2 - 3 next rerolling of them in cold rolling mills. Sleeves pierced of ingots are rolled in pilger mill to conversion hot rolled conversion tubes while taking into account 1 - 2 rerolling processes in cold rolling mills. Ingots with diameter up to 500 mm are pierced in skew rolling mill to sleeve at one piercing operation with elongation value μ = 1.2 - 1.4. Ingots with diameter 540 mm and more are pierced at two piercing operations with elongation value μ1 = 1.2 -1.4 and μ2 = 1.1 - 1.3 respectively. Conversion elongated cold rolled tubes after rolling them to intermediate size are subjected to austenitization in mode providing temperature of furnace space at time moment of charging in range 1000 - 1100°C, heating according to power of furnace up to 1050 ± 15°C, soaking at such temperature for 1 min per 1 mm of tube wall thickness and cooling in air. Conversion elongated cold rolled tubes of ready size after rolling and austenitization are subjected to heat treatment - tempering in mode providing charging at 700 - 730°C; heating according to power of furnace; soaking at temperature 685 ± 15°C for 5 - 5.5 h; cooling in air.

EFFECT: strict geometry size of diameter and thickness of walls of elongated conversion tubes, lowered metal consumption, enhanced operational reliability of ready products.

8 cl, 2 tbl

FIELD: electrical engineering.

SUBSTANCE: proposed method that can be used to control systems incorporating frequency converter with off-line voltage inverter and induction motor operating into mechanisms handling alternating cyclic load (deep-well pimps, crank gear drive mechanisms, and the like) involves automatic correction of motor speed as function of voltage deviation in dc current section from maximal permissible value which makes it possible to dispense with energy dissipating and rectifying devices affording recuperation mode.

EFFECT: reduced cost and maintenance charges, enhanced operating reliability.

1 cl, 1 dwg

FIELD: rolled tube production.

SUBSTANCE: method comprises steps of heating ingot-billets; piercing them in helical rolling mill to sleeves with different lengthwise elongation factors μpr and μpr1; rolling in pilger mill with elongation factor μpil . Ingot-billets are pierced to sleeves at different lengthwise elongation factors μpr, μpr1, μpr2 where maximum elongation value μpr2 corresponds to front end of sleeve forming guided end of tube in pilger mill. Elongation factor of front end of sleeve is decreased from μpr2 to μpr due to drawing roll apart along length (0.15 -0.20)LT forming guided end of tube in pilger mill and determined according to expression μpr2 = (1.4 -1.6)μpr where μpr -elongation factor in piercing mill at stable rolling process of central portion of sleeve equal to (0.65 -0.75)LT. Elongation factor of back end of sleeve is increased from μpr to μpr1 due to drawing rolls together along length of sleeve equal to (0.1 - 0.15)LT forming pilger head determined according to expression μpr1 = (1.3 -1.5)μpr.

EFFECT: lowered metal consumption, enhanced efficiency of pilger mills, prevention of crumbling back ends of sleeves.

3 cl, 1 dwg, 1 tbl

FIELD: tube rolling.

SUBSTANCE: proposed method includes making of ingots with subsequent turning and drilling of central hole, heating of ingots to plasticity temperature, piercing in skew rolling mills into shells with fit to diameter of 8-16% and rolling on pilger mills with tolerance to wall of +20/-15%. Thickness of cut metal layer at turning of ingots is increased with increased in diameter whose value is found from expression ▵S=0.0125*D where D is diameter of ingot, mm. Diameter of central drilling of ESR ingots is found from expression ddr=do+▵(Dc-Do) where do=100 mm is value of central drilling of ingots, diameter 500 mm; ▵=0.075 is coefficient taking into account outer diameter of ingots; Dc is current of outer diameter of ingots; Do - is ingot, diameter 500 mm. Reduction of ingots at piercing is decreased with increase in diameter and is found from expression εtot(dc-do) where εo is reduction of ingots, diameter 400 mm, equal to 16%; εt is coefficient = 0.003%/mm; dt is current diameter of ingots, mm; do is diameter of ingot, 400 mm. Rolling of tubes on pilger mill is carried out with tolerance in thickness of wall equal to +15/ - 10%.

EFFECT: reduced power consumption at piercing, reduced consumption of metal at making of boiler tube from ESR ingot, improved mechanical properties of tube metal.

4 cl, 2 tbl

Up!