RU2188100C1 - Pulling and cutting unit of shape-bending aggregate - Google Patents

Abstract

FIELD: equipment for working rolled strips, particularly for making cold bent merchant rolled shapes. SUBSTANCE: pulling and cutting unit of shape bending aggregate includes drum type shears having drums mounted in housing on shafts. Lower shaft is driven one; it is kinematically joined with pair of feeding horizontal rollers. Upper shaft is driven through gearing. In cross grooves of drums cutters are arranged. Paired horizontal rollers are mounted at outlet of unit. Lower roller of said pair is kinematically joined with lower shaft of shears. Two pairs of vertical rollers are mounted with possibility of separate vertical motion between feeding rollers and shears. It is possible to change spacing between them in crosswise direction. In housing of shears at control side oval opening is formed in level of crossing cutting circles of cutters. Upper gearing of shears includes two gear wheels of the same width, one of those gear wheels may rotate. EFFECT: reduced metal consumption at making merchant bent shapes with small cross sections, enhanced geometry of such shapes. 2 dwg

Description

 The invention relates to equipment for processing (finishing) strip products and can be used in the production of long cold-rolled sections from a relatively thin and narrow strip blank.

As a blank for such profiles, cold-rolled coiled strip steel with a tensile strength σ _b ≤ 650 MPa is usually used, which before profiling is cut into measured lengths with scissors of one type or another (for example, flying drum) installed directly in front of the profile bending mill. As a rule, feed rollers are located in front of the scissors, which on light mills can simultaneously serve as pulling rollers transporting the strip blank from the unwinder to the scissors. Cutting devices of roll forming units are described, for example, in the book under the editorship of I.S. Trishevsky "Production of bent profiles (equipment and technology)", M., "Metallurgy", 1982, p. 132-144, and the design of flying drum scissors with feed rollers - in the book by A. A. Korolev "Mechanical equipment of rolling and pipe shops", M., "Metallurgy", 1987, p. 121-125.

 A cutting device (drum-type scissors) with knives protruding during cutting is known, in which the knife is rigidly fixed in the groove by the wedge block on the upper drum and the U-shaped frame with the knife is fixed in the groove of the lower drum, the extension of which occurs automatically (see Pat USA 3057239, cl. 83-337, publ. 09.10.62). The disadvantage of this device is the complexity of its design and operation, which increases production costs.

 Drum flying scissors are also known in which the vertical axial plane of the drums is inside their transverse grooves, and an additional through groove with a right angle in the cross section and holes on its vertical face for adjusting the knife with bolts is made on the larger drum (see US Pat. RF 2103117, C. B 23 D 5/12, publ. 01/27/98). The disadvantage of such scissors is the possibility of obtaining a large "run" of the lengths of the cut strips, which leads to excessive metal consumption.

 The closest analogue to the claimed device is a cutting device according to US Pat. RF 2103118, class In 23 D 25/12, publ. 01/27/98.

 This device contains drum scissors, in the transverse grooves of the drums of which there are knives, with a lower drive shaft and an upper shaft drive through gears, and a pair of horizontal feed rollers kinematically connected with the lower scissors shaft, and is characterized in that the drums have different diameters with a ratio of along the circumferences of the cut within 1.2 ... 1.4, and the knives in the grooves of the drums are fastened with three wedges each.

 A disadvantage of the design of this device is the possibility of obtaining rods with an increased “run-up” of lengths and deterioration of the geometry of the finished profiles due to insufficient centering of the cut strip.

 Indeed, the presence of only feed rollers in front of the scissors can lead to slippage of the stretched strip between the rollers (with insufficient pulling force), which will increase the "run" of the lengths of the cut rods. The absence of vertical centering rollers in front of the scissors can lead to an unacceptable (for the manufacture of bent profiles) cutting cut, which affects their geometry. In both cases, this leads to an increase in metal consumption, including due to the growth of marriage.

 An object of the invention is to reduce the consumption of metal in the production of high-quality bent profiles of small sections and improve their geometry by increasing the accuracy of cutting the moldable strip into measured lengths and its centering.

To solve this problem, a pulling-cutting block of a roll forming unit containing drum scissors with drums installed in the frames on the shafts, in the transverse grooves of which are placed knives, with a lower drive shaft and an upper shaft drive through gears, and a pair of horizontal feed rollers kinematically connected with the lower scissors shaft, at the outlet of the block, a pair of horizontal rollers is additionally installed, of which the lower is kinematically connected with the lower scissors shaft, and only the lower rollers are driven, and between two pairs of vertical rollers are mounted with feed rollers and scissors with the possibility of individual vertical movement with a variable lateral distance between the rollers, while an oval hole is made in the base of the scissors on the control side and at the level of the intersection of the circumferences of the cuts of their knives, and the upper gear of the scissors is composed of two gear wheels of the same width and with the possibility of turning one of them on the shaft within an angle of 1.0 ^o ... 1.5 ^o .

 The value of this angle is determined empirically (see below).

 The essence of the technical solution found is to improve the design of the known cutting device (US Pat. RF 2103118) by installing additional pairs of horizontal and two pairs of vertical rollers in the pulling and cutting unit, as well as to improve the setting of the scissors, which improves the quality of the cut and bent profiles formed from the cut strip, and ultimately reduces the consumption of metal in the production of such profiles.

 The proposed pull-cutting unit is schematically shown in figure 1 (view from the control side), and in figure 2 is an embodiment of a possible rotation on the upper shaft at a predetermined angle of one of the halves of the upper gear of the drum scissors.

 The block contains a pair of horizontal feed rollers 1 (the arrow shows the direction of movement of the strip); located behind them are two pairs of vertical rollers 2 mounted on axles 3; drum scissors with upper 4 and lower 5 reels mounted in beds 6 on shafts 7 and 8, and an additional pair of horizontal rollers 9 behind the scissors. All units of the block are installed on a common plate 10, which allows you to remove and install the entire block on the unit.

 The lower shafts 11 and 12 of the horizontal rollers and scissors 8 are kinematically connected to each other through sprockets 13, for example, by a Gall chain 14, for tensioning which a tension sprocket is installed on the frame 15. As shown by an experimental check of the block (see below), if horizontal rollers are present a pressure device (spring-loaded clamping screws) for reliable transportation and tension of the strip, it is enough to have only the lower rollers driven, which simplifies the manufacture and operation of these units.

 The axis of the vertical rollers 3 are screwed into the supports 16 and fixed with nuts 17, which allows the rollers 2 to be installed at different heights; this is necessary for asymmetric wear of the working surface of the rollers. The distance between the supports 16 may vary depending on the width of the strip.

 In one of the scissor beds 6, located on the control side of the block, an oval hole 19 is made at the intersection of the circumferences of the cut 18, which makes it possible to control the values of their radial overlap and horizontal clearance when setting up the scissors.

 The upper shaft 7 of the scissors is driven from the lower one using a pair of gears mounted on the drive side of the unit, i.e. opposite to the control side. In order to avoid “backlash” in the gearing of the gears, which inevitably leads to an increase in the gap between the knives and, as a consequence, to a deterioration in the quality of the cut (the appearance of a burr on the ends of the rods), the upper gear is made of two gears of the same width.

 Shown in FIG. 2, the device allows one of the halves of the upper gear 20 to rotate on the shaft 7 within the specified angle (the width of the keyway of this half is slightly larger than the width of the key), which ensures tight contact between the teeth of the upper and lower gears during their rotation. The shift of the teeth of both halves of the upper gear (and the rotation of one of them on the shaft) is carried out using two compression springs 21 (see figure 2), the deformation of which is carried out by the coupling bolts 22 passing each through the holes of the two pins. One of these pins (23) is mounted on the surface of, for example, the left half of the upper gear (external to the scissor frame on the drive side), and the second pin (24) passes through the hole in this half of the gear (the diameter of the hole is larger than the diameter of the pin) and screwed into the surface of the other half of the gear mating with the first. When the coupling bolt 22 is rotated (and moved), the spring 21 is compressed and one of the halves of the upper gear 20 is rotated on the shaft 7: the teeth of two gear wheels of this gear abut against the teeth of the lower gear.

 Before cutting, the strip blank (its front end) from the unwinder of the roll forming unit enters the feed rollers 1 and is pulled by them to the vertical rollers 2, where it is centered, and then passes into the gap between the scissor drums and is captured by horizontal rollers 9 at the exit of the block. Directly behind the block in the course of profiling, there is 1 (master) mill stand with lead-in wires, and the distance from this stand to scissors is less than the minimum length of the cut rod (usually 3 m). The strip captured by the rolls of the first stand is cut after some time to obtain its required length and is subjected to molding.

A pilot check of the inventive device was carried out on the unit "0.5-2.5" CJSC "Rolled - bent profile" OJSC "Magnitogorsk Iron and Steel Works" when profiling strip billets with a thickness of 0.5 ... 2.5 mm and a width of 50 ... 250 mm from steels with tensile strength σ _b ≤ 500 MPa. The quality of the cut, the length of the bent profiles and their geometry were evaluated in comparison with the profiles obtained using the known cutting device (according to US Pat. RF 2103118).

The "shift" of one of the halves of the upper gear showed that a rotation angle of 1.0-1.5 ^{o is} sufficient, and at a lower value there is a "backlash" in engagement.

 The “run-up” of lengths when using the proposed device was 1.2 ... 1.6 times less, the yield of bent profiles of high dimensional accuracy was 62. ..78% (ie increased by 8 ... 15%), and marriage (due to unsatisfactory cutting) to 0.1%. As a result of this, the metal consumption was less than by using a known cutting device by an average of 1.5%.

 Thus, the experimental verification confirmed the acceptability of the claimed object for solving the task and its advantages over the known object.

 According to the MMK Central Laboratory, the use of the technical solution found in the production of high-quality bent sections of small sections will reduce their cost by at least 5% (due to a decrease in metal consumption, including by reducing scrap by almost 1.5 times), and an increase in output high precision rental will give a corresponding increase in profits.

Concrete example
The pull-cutting block of the roll forming unit for strip billets with a thickness of 0.5 ... 2.5 mm and a width of 50 ... 250 mm with σ _b ≤ 500 MPa consists of the nodes shown in figures 1 and 2. The maximum speed of the strip 0.8 m / s, range of lengths when cutting 3 ... 6 m.

 The diameter of the horizontal feed rollers is 160 mm. An additional 161 mm (this ensures constant tension of the strip), the length of their barrels is 260 mm; the diameter of the working part of the vertical rollers is 40 mm, the magnitude of their vertical movement is 9 mm. The pressure of the horizontal rollers on the strip is regulated by the clamping screws located in the pillows of the rollers.

 The diameter of the upper drum of scissors is 369 mm, of the lower 305 mm, the width of the drums is 260 mm. The position of the knives installed in the grooves of the drums is adjustable both vertically and horizontally. In the scissor bed, on the control side of the block, at an altitude of 275 mm from the base, there is an oval hole 80 • 60 mm.

The lower shear shaft is driven in rotation from an engine with N = 16 kW through a two-stage gearbox. The gear of the upper shaft (gearing module m = 8) consists of two halves 40 mm wide each, one of which can be rotated on the shaft within 1.0 ^o ... 1.5 ^o .

 Asterisks for the Gall chain with = 15.875 mm are installed on all lower shafts from the control side of the block.

All nodes are mounted on a common slab with an area of 1150 • 550 mm ² .

Claims (1)

Pulling-cutting block of a roll forming unit, mainly of light type, containing drum scissors with drums mounted on the shafts on the shafts, in the transverse grooves of which there are knives, with a lower drive shaft and an upper shaft drive through gears and a pair of horizontal feed rollers kinematically connected to the lower shaft scissors, characterized in that it additionally contains at the output a pair of horizontal rollers, of which the lower is kinematically connected with the lower shaft of the scissors, and only the lower two pairs of vertical rollers with a variable transverse distance between the rollers mounted between the feed rollers and scissors with the possibility of individual vertical movement, while an oval hole is made in the base of the scissors on the control side and at the level of the intersection of the circumferences of the cut of their knives, and the upper gear of the scissors composed of two gears of the same width and with the possibility of rotation of one of them on the shaft within an angle of 1.0-1.5 ^o .

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