RU2391194C1 - Method of arc welding of strips at continuous butt-welding machines and device to this end - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention can be used for contact arc welding of strips at specialised arc welding machines installed in high-efficiency pipe welding and profiling plants etc. Common bed supports guillotine shears with top and bottom supports, internal centering device, welding torch and copper plate with strip ends clamps to position strips ends nearby welding zone. Proposed device comprises also carriage drive to move it in the guide and two centering posts with stripe ends clamps. Post with strip front end clamp is furnished with welding gap regulator and represents a laver that can deflect vertically from hinge together with clamped strip to make a gap between strip edges. Stop is fixed on the carriage to act on post center, between hinge axle and clamped strip.

EFFECT: optimised strips ends preparation for welding with required welding gap.

2 cl, 3 dwg, 1 ex

Description

The present invention relates to welding production, and in particular to methods and devices for welding strips, performed on specialized machines that are installed in high-performance continuous metallurgical units, such as pipe welding and roll forming mills, pickling lines, etc.

Known, for example, a welding machine with a mechanized installation of strips / ed. testimonial. USSR No. 308837, class IPC 5, V23k, 101/16, 09.VII.1969 /, including a bed on which the lower support and the upper support of scissors are mounted with the possibility of rotation, as well as a centralizer made in the form of a cylinder, the piston rod of which is mounted on the fixed part of the bed, however, the machine includes devices that transmit strips with pre-cut ends from the cutting position to the welding position.

The disadvantages of this option for welding strips are associated with the need to create some reserve strips, in the form of loops, in front of and behind the welding machine for the smooth operation of the transmitting devices of the machine when installing strips. These loops are created by loop-forming mechanisms that are installed on both sides of the welding machine. Transport carriages and loop-forming devices increase the size and weight of welding machines and in some cases, for example, during the reconstruction of metallurgical units due to lack of space in length, this creates difficulties with the use of such machines. In addition, an increase in the mass of the welding machine leads to an increase in the cost of its manufacture.

Known, for example, is also a method of connecting the ends of the strips for welding and a device for its implementation / ed. testimonial. SU No. 1625638 A1, cl. B23k, 37/04, 02/07/91 /, in which the first strip is fed all the way to form a bend on it, the strip is centered, the second strip is fed all the way to form a bend on it, centered, clamped, then the edges of both strips are cut off and simultaneously connect them with rotary tables on both sides.

The disadvantage of this method and device is the need to withdraw the first strip behind the machine to raise the scissors to the cut position and feed the ends all the way to a narrow slot, which makes installation difficult, centering the strips with two centering devices when the bands are sickle-shaped requires rather complicated devices and time to eliminate the skew of the strips during installation , while cutting both ends of the strips simultaneously necessitates a doubling of the cutting force on the scissors, and a double cut complicates the maintenance of the scissors when setting up the knives. In addition, the welding gap on the machine is adjusted relative to the position of the welding torch on both sides, which does not always ensure accuracy.

Closest to the proposed invention in terms of technical nature and the achieved result are a method of welding strips and a machine for its implementation MCO 16.06, the design of which is described in the article by A. Novitsky and Mokeicheva V.G. “Strip welding in metallurgical production”, “Heavy engineering” No. 5, 2002, pp. 22-26. The method includes feeding the ends of the strips into the cutting zone, centering the rear and front ends with internal and external centering devices, trimming the ends of the strips with guillotine shears with upper and lower calipers, while after trimming both ends of the strips remain clamped in stationary clamps, and the welding device has the ability to move from the trim position to the weld position. The implementation of this method is carried out on a flash butt welding machine, comprising a movable and fixed bed with clamps provided with clamping jaws, and two pairs of pulling rollers for feeding strips at the entrance and exit of the machine with the possibility of reversing.

The disadvantage of this method and device for its implementation is that the implementation of trimming the rear and front ends of the strips with one pair of scissors without shifting the trimmed strips leads to the joining of the ends of the strips for welding without a gap, which is permissible for arc welding of strips up to 2 mm thick without a significant increase in welding power source. Welding thicker strips without a gap requires the use of higher welding currents to weld the joint, while in the joint there is a gain to be cleaned in the line of the unit. To obtain welds with minimal reinforcement, it is necessary to create a welding gap between the edges of the strips and in this case it is necessary to equip the machines with special devices for displacing the joined strips and additional adjustment of the position of the welding torch.

In the present invention, the issue of achieving a technical result is solved by optimizing the preparation of the ends of the strips for welding with the formation of the required welding gap between the welded strips, improving the arc welding machine when installing strips for subsequent welding, simplifying machine maintenance and ensuring safe operation of the machine without the use of additional nodes.

The technical result with the achievement of the above effect is ensured by the fact that in the method of arc welding of strips on machines of continuous metallurgical units, including feeding the ends of the strips into the cutting zone, centering the rear and front ends with a centering tool, cutting the ends of the strips with guillotine shears with upper and lower calipers and welding, after feed into the line of the rear end of the previous strip, it is stopped near the cutting axis, the strip is centered, the first clamp is clamped, the centralizer is pulled apart and the rear end of the strip is cut, then the front end of the next strip is fed and it is stopped near the cutting axis, the strip is centered and clamped in the second clamp, the centralizer is pulled apart and the front end of the strip is cut, the upper scissor support is lifted up, the carriage with lining and burner is moved to the joined strips and the front end clamp clamp rack , the displacement drive rotates the stand up to the stop together with the front end of the strip clamped in it with the formation of a welding gap between the joined stripes, then the welding torch is installed on the gray a single gap, lower the clamps, raise the first and second clamps and carry out welding.

A device for implementing the proposed method is a welding machine containing guillotine shears fixed on a single carriage with upper and lower calipers, a centering device, a welding torch and a copper lining located under it with clamps of strip ends located near the welding zone, a drive for moving the carriage along the guide, and also two racks with clamps of strips, while the clamp rack of the front end of the strip is made in the form of a lever with the ability to rotate the clamp around the hinge with the impact on the rack stop a drive moving the carriage, the rack is provided with a welding gap regulator and a return spring, and the carriage stop is arranged to impact on the rack at half the distance between the pivot axis and sandwiched strip

The inventive method of flash butt welding of strips and a device for its implementation are shown in figures 1, 2 and 3,

where in Fig.1 schematically shows the inventive welding machine (in section along the axis) in the position of the cut with the stripes passing through it,

figure 2 schematically shows the inventive welding machine (in the context of the axis) in the position of welding of thin strips without a gap,

figure 3 schematically shows the inventive welding machine (in the context of the axis) in the position of welding strips with a gap.

The welding machine contains guillotine shears 2 mounted on a single carriage 1 with upper 3 and lower 4 calipers, a centering device 5, a welding torch 6 and a copper lining 7 located under it with clamps of the ends of strips 8 and 9 located near the welding zone, a carriage drive 10 along the guide 11, as well as two racks 12 and 13 with clamps of the rear 14 and front 15 ends of the strips. The rack 13 of the clamp 15 of the front end of the strip is made in the form of a lever 16 with the possibility of turning the clamp 15 around the hinge 17 with the stop acting on the rack 18 from the drive for moving the carriage 10, while the rack 13 is equipped with a welding gap adjuster 19 and a return spring 20, and the carriage stop 18 installed with the possibility of impact on the rack 12 at half the distance between the axis of the hinge 17 and the clamped strip 21.

The inventive method of arc butt welding in the inventive device is as follows:

- at the end of the processing of the roll in the metallurgical unit, the rear end of the previous strip 21 stops in the welding machine near the scissors 2;

- lower the upper caliper 3 of the scissors 2 to an intermediate position and center the strip 21 with the centering 5, clamp with a clamp 14, open the centralizer 5, cut the back end of the strip 21 and raise the upper caliper 4 of the scissors 2 with the centering 5 to the initial position;

- then feed the front end of the next strip 20 and stop it near the cutting axis of the scissors 2;

- lower the upper support 3 of the scissors 2 to an intermediate position, center the front end of the strip 22 with a centralizer 5, clamp the strip 22 in the clamp 15, open the centralizer 5, cut the front end of the strip 22, lift the upper support 4 of the scissors 2 up to the stop;

- move the carriage 1 with the drive 10 and with it the welding lining 7 with the torch 6 to the joined strips 21 and 22 to the welding position, while the welding lining 7 stops at the junction of the strips 21 and 22, and the welding torch - in the middle of the gap between the strips during welding thick strips or over joined strips when welding thin strips without a gap;

- lower the clamps 8 and 9, raise the clamp 14 of the rear and clamp 15 of the front ends of the POS and carry out welding;

- then raise the clamps 8 and 9 and give permission to transport the welded strips to the unit, and the carriage 1 is moved by the drive 10 to the initial position - the position of the trim strips, while the stand 13 (if the welding gap was set) under the action of its own weight and return spring 20 occupies a vertical position, and the carriage 1 of the machine - the initial position before the next welding.

The welding machine is set up when switching to processing strips of another assortment.

To ensure welding of the strips without a gap, the regulator of the welding gap 19 is turned out, reducing the clearance between it and the post 13 to zero, thereby eliminating the possibility of the post 13 and the clamp 15 turning around the hinge 17.

To weld the strips with a gap, screw the regulator of the welding gap 19 until a gap is formed between it and the stand 13, equal to half the welding gap, and this is done. After trimming the ends of the strips and moving the carriage 1 to the “welding position”, the stop 18 acts on the rack 12 by the drive force of the carriage 10 and deflects it relative to the hinge 17, removes the front end of the strip 21, clamped in the clamp 15, from the edge of the strip 20 to the required gap, with this carriage 1 due to the impact of the shortened stop 18 in the middle of the lever of the rack 13 provides a shift of the welding torch 6 to the middle of the welding gap, which eliminates the additional operation of setting the position of the welding torch 6.

Example of execution: when welding strips with a thickness of 5 mm in a CO ₂ medium with a filler wire of 2 mm at a current of 400 A, the minimum reinforcement in the joint is ensured with a gap between the strips of 3 mm and a welding speed of 20 m / h, the clearance between the welding gap adjuster and the stand in 1.5 mm provides a gap between the strips of 3 mm, the welding torch is automatically installed at a distance of 1.5 mm from the end of the clamped rear end of the strip.

Thus, the proposed method for arc welding of strips on machines of continuous metallurgical units, in which the ends of the strips are fed into the cutting zone, the rear and front ends are centered, the strip ends are trimmed with guillotine shears with upper and lower calipers, and after the rear end is fed into the line of the previous strip, it is stopped near the cutting axis, the strip is centered, it is clamped with the first clamp, the centralizer is pulled apart and the rear end of the strip is cut, then the front end of the next strip and set it near the cutting axis, center and clamp the strip in the second clamp, spread the centering device and cut the front end of the strip, lift the upper scissors support up, move the carriage with a lining and a burner to the joined strips and the rack of the clip of the front end of the strip, with the displacement drive turn the rack to the stop together with the front end of the strip clamped in it with the formation of a welding gap between the joined strips, then the welding torch is installed in the middle of the gap, the clamps are lowered, the first one is lifted and the second clamps and perform welding, which allows us to solve the problem of optimizing the preparation of the ends of the strips for welding with the formation of the required welding gap between the strips, eliminating the setting of the position of the welding torch relative to the gap. This greatly simplifies maintenance of the welding machine, and the implementation of the device for implementing the method using the machine for arc welding of strips of continuous metallurgical units, comprising guillotine shears fixed to a single carriage with upper and lower calipers, a centering device, a welding torch and a copper lining located under it with clamps of ends strips located near the weld zone, a drive for moving the carriage along the guide, and also two racks with clamps of strips, while the clamp rack of the front end the bar is made in the form of a lever with the possibility of turning the clamp around the hinge with the stop being exposed to the support from the carriage displacement drive, while the stand is equipped with a welding gap adjuster and a return spring, and the carriage stop is installed with the possibility of acting on the stand at half the distance between the hinge and the clamped strip :

- improve accuracy when installing strips for subsequent welding without the use of additional tuning mechanisms and machine components and thereby improve the design of the machine for arc welding;

- to ensure the safety of staff by eliminating the presence of stocks of loop loops near the welding machine and to facilitate the work when rebuilding the welding machine,

- more efficient use of arc welding machines installed in high-performance continuous metallurgical units, eliminating the need for stripping reinforcement of welds.

Claims (2)

1. A method of arc welding of strips in continuous metallurgical units, in which the rear end of the previous strip is stopped near the cutting axis, the strip is centered, clamped with the first clamp, the centering device is cut and the rear end of the strip is cut, then the front end of the next strip is fed and stopped near the cutting axis , center and clamp the strip in the second clamp placed on the stand, mounted with the possibility of its deviation from the vertical position, part the centering device and cut the front end of the strip, then move the carriage to the joined strips in the welding position with the welding torch fixed on it and the lining located under the torch and using the stop fixed on the carriage, reject the said strut together with the front end of the strip clamped in it until a welding gap is formed between the joined strips with the placement of the welding torch in the middle of it, after which the ends of the strips are pressed near the welding zone by the clamps, the first and second strip clamps are lifted and welding is carried out. 2. Device for arc welding of strips in continuous metallurgical units, containing guillotine shears fixed to a single carriage with upper and lower calipers, a strip centering device, a welding torch and a copper lining located under it with clamps of strip ends with the possibility of their placement near the welding zone, a movement drive carriages along the guide, as well as two racks with clamps of the ends of the previous and next strips, while the rack with clamps of the front end of the strip is equipped with a welding gap and return dinner and is designed as a lever with the possibility of deviation from the vertical position relative to the joint abutment means mounted on the carriage with the possibility of its impact on the rack in the middle between the pivot axis and sandwiched strip.

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