RU2183524C1 - Uncoiler for shape bending aggregate - Google Patents

Abstract

FIELD: finishing of rolled strips, particularly equipment for making cold bent rolled bars. SUBSTANCE: uncoiler of shape bending light-type aggregate is designed for coils with predetermined value D of maximum diameter. Uncoiler includes housing in which two side members for aligning coil and supporting rollers are mounted. Novelty is small diameter supporting roller mounted in addition between above mentioned supporting rollers with diameter dp and under lower than level of mounting those rollers. Side members are cross like ones, they have diagonal connecting links. The last (according to rolling process direction) supporting roller is driven one and it has gummed barrel. Linear velocity vector of rotation of said supporting roller in its contact point with coil is opposite to rolling direction. Diameter of supporting rollers dp=(0.08-0.10) D; spacing between their axes l= (0.70-0.75)D. EFFECT: less loss of yield due to lowered labor consumption for making small cross section bent shapes in the result of preventing defects at uncoiling strip. 2 cl, 1 dwg, 1 ex

Description

 The invention relates to equipment for processing (finishing) strip products and can be used in the production of long cold-rolled sections of rolled products with relatively small sections.

Thin cold rolled steel with a tensile strength δ _of ≤650 MPa is usually used as a blank for such profiles. Rolls of the workpiece entering the roll forming unit of light type are installed in the unwinder, in which the strip is unwound due to the rotation of the roll. Drum-type unwinders for medium and heavy roll forming units are described in sufficient detail in the book under the editorship of I.S. Trishevsky "Production of bent profiles (Equipment and technology)" M., "Metallurgy", 1982, p. 118-120. The main disadvantage of this type of unwinder is the need to coordinate the diameter of the drum with the inner diameter of the unwinding roll. In addition, drum unwinders are quite complex in design and require qualified service. On roll-forming units of a light type, it is possible to use decoilers that are simpler in design and maintenance.

 A device for unwinding rolls of strips with a thickness of 1.2 mm is known, equipped with special rollers to capture the end of the strip (see English Pat. 988334, class B 23 K, publ. 07.04.65). A device for unwinding rolls is also known, in which, to prevent "fluffing" of the rolls (i.e., their spontaneous unwinding), there is a rotating platform and idle rollers with axes parallel to its rotation axis (see French application 2258230, class B 21 C 47/18, publ. 18.08.75 g.). The disadvantage of these devices is the relative complexity of the design, which increases the cost of their maintenance.

 The closest analogue to the claimed object is an uncoiler for a lightweight mill, described in the book of V.I. Davydova and M.P. Maksakova "Production of bent thin-walled profiles", M., Metallurgizdat, 1959, p. 48, fig. 46.

 This uncoiler contains a housing with two sidewalls and support rollers mounted on it and is characterized in that the sidewalls are made in the form of disks, the distance between which is adjusted by screws in accordance with the width of the roll strip, and the edges of the disks from the input part are bent outward to facilitate installation of the roll to the unwinder.

 The disadvantage of this design of the unwinder is the impossibility of its use for rolls of increased weight (3000 kg), since in this case it is difficult to unwind the roll (it is possible to “pull” it out of the unwinder). In addition, with a large roll diameter (1.6 m), the surface of the sidewall-disks is inevitably damaged by the edges of the moving strip (when the roll is rotated), which, in turn, will worsen the condition of these edges and, ultimately, the quality of the profiles.

 An object of the invention is to reduce labor costs in the production of high-quality bent profiles of small sections by preventing defects that occur during unwinding of a rolled strip billet.

To solve this problem, the uncoiler of a light-type roll-forming unit for rolls of strip billets with a given value D of maximum diameter, containing a housing with sidewalls and supporting rollers mounted on it, two supporting rollers, between these rollers with a diameter d _p and below their level, a support roller is additionally mounted smaller diameter, while the supporting roller following the rolling is made driven with a gummed barrel and the linear velocity vector of its rotation at the point of contact of the roll is opposite to the rolling direction, and the diameter of the support rollers is d _p = (0.08 ... 0.10) • D with a distance between their axes l = (0.70 ... 0.75) • D, and the centering sidewalls are made crosswise with diagonal ligaments.

 The given dependences were obtained during the processing of experimental data and are empirical.

 The essence of the technical solution found is to improve the conditions of unwinding the roll by giving it an additional rotational force from the gummed drive roller and reducing the contact surface of the side edges of the strip (ends of the roll) with the centering sidewalls. Also important is the fact that the strip is transported from the top of the roll, and not from its bottom.

 Indeed, as follows from the drawing, this option of transporting the unwinding strip is possible only when the roll is rotated clockwise, and the drive support roller is opposed. If, however, the direction of rotation of the roll and this roller is reversed, the strip will be transported from the bottom of the roll when it is constantly clamped in the area where the roll touches the surface of the drive roller, which will lead to intensive wear of its surface and to injury to the strip surface.

 In addition, experiments have shown (see below) that the diameter of the drive roller must be consistent with the diameter (and, consequently, the weight) of the roll in order to create the optimal load on the contact surface unit of the roller barrel, which allows the roll to rotate without slipping on this surface. The distance between the support rollers should also be optimal: if l is too small, it is possible for the “roll” of the roll from the rollers (during rolling), from the force of the pulling rollers (not shown) located in front of the cutting device, and with a large l, the wear of the drive roller barrel will increase ( the bigger it is, the “lower” the roll is from the level of the rollers).

 The supporting roller of a smaller diameter (it is fully loaded only with a small diameter and light weight of the roll) ensures that there is no “failure” of the roll between the support rollers while reducing its diameter during unwinding.

 The proposed unwinder is shown schematically in the drawing (horizontal arrow is the direction of movement of the workpiece along the unit).

On the housing 1 of the unwinder, support rollers 2 and 3 with a diameter d _{p are} installed in supports above and at a distance l from each other, of which one (3), located closer to the roll forming mill, is driven and with a gummed barrel (to improve traction with the roll strip); the value l = (0.70 ... 0.70) • D and d _p = (0.08 ... 0.10) • D. From the bottom of the housing 1, on the vertical axis yy of the unwinder, between the support rollers 2 and 3, a support roller 4 is mounted with a diameter <d _p . The vector v of the linear speed of rotation of the roller 3 (more precisely, the horizontal projection of the vector) at the point of contact with the roll 5 is opposite to the rolling direction.

 Roll 5 rests on rollers 2 and 3 and rotates clockwise. The unwinding strip 6 bends around the bottom of the guide roller 7, mounted in racks 8 on the housing 1. Centering the roll - using two crosswise sides 9 made with the possibility of changing the distance between them when changing the width of the roll and installed on the housing in the racks 10. To strengthen their sides vertical and horizontal slats are fastened with diagonal ligaments 11.

 Before unwinding, the roll is loaded into the unwinder between the sidewalls and mounted on the support rollers. By rotating the roller 3, the roll is rotated so that the front end of the strip passes under the roller 7 and then to the pulling rollers that transport the strip blank to the cutting device. Changing the distance between the sidewalls (perpendicular to the plane of the drawing) is carried out by moving the shanks 12, welded to the crosses and lying on the supporting strips between the uprights 10.

 As the diameter of the roll decreases during the unwinding process, it drops down to the stop in the support roller 4, on which it remains until the end of the unwinding.

 A pilot test of the claimed device was carried out on a roll forming unit of light type "0.5-2.5" CJSC "Rolled - bent profile" OJSC "Magnitogorsk Iron and Steel Works". The operation of the device was compared with the work of the known unwinder (see the description of the closest analogue above), which was previously operated on the specified unit, according to the results of sorting the bent profiles due to defects obtained during unwinding. The comparison showed that sorting when working with the unwinder of the proposed design decreased by 2 ... 3 times or, on average, by 0.8 abs.%.

 In addition, machine downtime for eliminating unwinding defects and for preparing the unwinder for operation was reduced.

 Thus, the pilot test showed the acceptability of the claimed object to solve the technical problem and its advantages over the known device.

 According to the central laboratory of the plant, the use of the proposed technical solution on the 0.5-2.5 unit (and similar ones) will allow reducing labor costs by production of bent profiles of small sections by at least 5%, which will increase the profit from the sale of rolled products.

Concrete example
The unwinder of the roll forming unit of light type is designed for unwinding rolled strip steel with a thickness of 0.5 ... 2.5 mm and a width of 50 ... 250 mm in rolls with a diameter of up to 1600 mm.

 Rolls are installed between two cross-shaped sidewalls (see drawing) with the length of their vertical and horizontal elements (channels 8) 1620 mm; the sidewalls are placed between the racks of the channel 14 using shanks.

Both support rollers are made with barrels 280 mm long and d _p = 144 mm (i.e. d _p = 0.09 D), the second (along the rolling) support roller - with a gummed barrel and driven by an engine with N = 5 kW The supporting roller mounted along the yy axis of the unwinder has D = 120 mm. This roller is set below the level of the support rollers by 340 mm and in the middle of the distance l = 0.725 • D = 1160 mm.

 The linear roll unwinding speed is 0.5 ... 0.8 m / s.

 The strip is transported from the top of the roll, passing under the guide roller D = 70 mm, mounted on racks.

 Uncoiler body - welded, from 18T channel.

Claims (2)

1. The unwinder of the roll forming unit of light type for rolls of strip billets with a given value D of maximum diameter, comprising a housing with sidewalls and supporting rollers installed on it, two centering rolls, characterized in that a supporting bolt is additionally mounted between these rollers with a diameter d _p and below their level a roller of a smaller diameter, while the last supporting roller during rolling is driven with a gummed barrel and the linear velocity vector of its rotation at the point of contact of the roll is laid in the rolling direction, and the diameter of the support rollers is d _p = (0.08-0.10) • D with a distance between their axes l = (0.70-0.75) • D.  2. The unwinder according to claim 1, characterized in that the centering sidewalls are made crosswise with diagonal ligaments.