RU2246386C1 - Machine for contact butt welding of strips - Google Patents

Abstract

FIELD: equipment for contact butt welding, mainly joining strips of comparatively small width in continuous metallurgical aggregates.

SUBSTANCE: machine is effectively used for contact butt welding of strips with width up to 150 mm. Machine includes movable and stationary housings with cantilever-type clamps; cut-off unit in the form of shears with holding device; centering unit and movable carriages for transporting strips from cut-off position to welding position. Cut-off unit is in the form of separate device mounted on bracket, rigidly joined with stationary housing and provided with sliding guides. Cut-off unit moves along said guides to axis of aggregate at trimming ends of coiled strips and it is moved aside at transporting strip in metallurgical aggregate. In order to provide interference-free motion of cut-off device at cross axis of aggregate, said device is in the form of alligator-construction lever type shears.

EFFECT: enhanced quality of welded joint, improved efficiency and enhanced operational safety of machine.

2 dwg

Description

The invention relates to welding production, and more specifically to machines for flash butt welding of strips installed in continuous metallurgical units (pipe welding, roll forming mills, etc.).

Such machines should have a short welding cycle to ensure the continuity of the line and guarantee a consistently high quality of joints in order to avoid breaks in strips during their transportation in the unit. To fulfill these conditions, welding machines are equipped with a number of additional mechanisms that automate not only the welding process, but also the entire set of auxiliary operations (cutting the ends of the rolls, centering and installing strips in the machine, stripping the wire, etc.). The operations listed above are performed in an automatic cycle with minimal staff involvement.

Known as an analogue of a flash butt welding machine / ed. testimonial. USSR No. 208152, cl. IPC N 05 b, 29/10, 03.IX.1966 /, containing pivotally connected movable and fixed beds, on which clamps are mounted, made in the form of a closed loop with a hydraulic drive clamping strips. A cut-off unit for cutting the ends of the rolls, made in the form of hydraulic guillotine shears with cutting knives installed in the upper and lower calipers, is also mounted on the fixed bed of the machine. In this case, the upper support of the scissors is connected with the rod of the hydraulic cylinder, and the lower support is made rotary. In addition, the machine is equipped with two movable carriages for the automated transfer of strips from the cutting zone to their welding zone, as well as a device for centering the strips, the clamping legs of which are located in the cutting plane of the scissors. The disadvantages of this design of the machine are associated with the low accuracy of the installation of strips in the jaws for welding due to the possibility of their helical deformation during centering.

Closest to the proposed invention in terms of technical nature and the achieved result, the prototype is a flash butt welding machine / ed. testimonial. USSR No. 308837, class IPC B23 k 11 / 02,15.XII.1969 /, incorporating all of the above mechanisms, and the design of the cutting unit, also made in the form of guillotine shears, is supplemented by a clamping element that allows you to fix the position of the strip on the lower support of the scissors in front of them centering and trimming. The scissor clamping element is made in the form of a frame that is lowered onto the strip and connected with the hydraulic cylinder of the upper caliper, and the hydraulic cylinder itself has a stepped cavity and an additional piston that allows the upper caliper to stop in an intermediate position.

This design allows to increase the accuracy of the installation of strips in the position of the weld, but does not eliminate the disadvantage inherent in the analogue and prototype associated with the closed design of both the clamps of the welding machine and the cutting device. In this case, it is necessary to remove the lower knife of the scissors from the zone of movement of the strip in order to avoid mutual damage during operation of the unit, which is ensured by the rotary design of the lower caliper of the scissors. Such a scheme significantly complicates the design of the scissors, complicates their adjustment and adjustment of the optimal gap between the knives. In turn, poor-quality adjustment of the scissors leads to the appearance of burrs on the edges, bending of the trimmed ends of the strip, which complicates their welding and adversely affects the quality of the weld.

Another drawback of the above construction is the fact that the transport carriage for setting the front end of the roll in the welding position during its course must fit into a closed loop formed by the vertical walls of the fixed bed, raised by the upper knife of the scissors and rotated by 90 ° the lower support of the scissors. This complicates the design of the carriage and increases the likelihood of breakdown of mechanisms in case of malfunctions in the operation of both the machine control system and its hydraulic circuit.

The task of the invention is to simplify the machine for flash butt welding of strips, reduce its metal consumption, increase reliability in operation.

The technical effect achieved in this case is an increase in the quality of the welded joint, an increase in the productivity of the machine and the safety of its maintenance.

The task with the achievement of the specified technical effect is ensured by the fact that for joining relatively narrow strips (up to 150 mm wide) in metallurgical units, a flash butt welding machine with a movable and fixed bed with clamps of an open-type cantilever design is proposed, and for automation of strip installation operations the specified machine is additionally equipped with a cutting unit with a clamping device, a strip centering device, as well as movable carriages for transferring the strip ends from a position cutting to the welding position. In this case, the cutting unit itself is made in the form of a movable block mounted on an arm rigidly connected to the fixed bed of the machine and having sliding guides that provide reciprocating movement of the cutting tool perpendicular to the axis of the metallurgical unit. The cutting tool can be moved along the guide hydraulic cylinder to the axis of the unit if it is necessary to trim the ends of the rolls and be removed from the zone of its operation when transporting the strip in a metallurgical line. For the smooth movement of the block when crossing the axis of the unit, it is proposed to perform it in the form of lever-type alligator scissors. The open contour of the cantilever clamps and the alligator open on the front side scissors design simplify the welding machine and facilitate its maintenance, and high precision when cutting and setting strips in the welding position is ensured by the rigid connection of the cutting block with the fixed bed.

The inventive machine for flash butt welding of strips is shown in figures 1 and 2. Figure 1 schematically shows a flash butt welding machine of strips with a cantilever design of clamping jaws in the initial position of the actuators. Figure 2 presents a side view of the cut-off unit of the machine, made in the form of a movable block with alligator shears, a strip centering device and a clamping device also in the initial position (a dash-dot line shows a fragment of scissors in the extended position at the time of strip cutting).

A flash butt welding machine comprises a fixed bed 1 pivotally connected to a movable bed 2. On both beds, cantilever clamping devices 3 are installed with jaws-electrodes 4 in which welding is performed. Transport carriages 5 and 6 are also mounted on the fixed bed of the machine for clamping the front and rear ends of the rolls, respectively, and automatically transfer them from the cutting position to the welding position, and on a separate bracket 7, a block of cutting scissors is also mounted rigidly connected to the fixed bed of the machine, which can to move the hydraulic cylinder 8 along the guides 9 perpendicular to the axis of the unit. The scissors are a lever alligator construction and cut the strip by the interaction of the upper 11 and lower 12 knives when the hydraulic cylinder 13 is turned on. A clamping device 15 with a clamping bar 16 is installed on a common axis with the two-arm scissors 16. It is connected to the scissors lever by a spring 17, which allows you to recess a clamping level when performing a cut. A device for centering strips 18 having a presser foot 19 is mounted on the upper plane of the scissor lever. The centering device can be moved along its guiding hydraulic cylinder 20; while the presser foot 19 will press the strip to the rear centering foot 21, which is attached to the body of the scissors. The foot 21 is interchangeable and must be replaced when changing the assortment of strips processed in the line.

Before the machine starts, all its mechanisms are in the initial position, as shown in Figs. 1 and 2. When the processing of the next roll ends in the machine line, its rear end stops in the area of the scissors of the welding machine and, upon the command of the operator, they are extended by the hydraulic cylinder 8 onto the axis unit. All operations to install the rear end of the strip in the car are performed in an automatic cycle in the following sequence:

- the upper arm of the scissors 10 is lowered by the hydraulic cylinder 13 to an intermediate position; while the clamping bar 16 presses the end of the strip to the plane of the lower knife 12;

- the centering cylinder 20 is turned on and its front foot 19 shifts the strip all the way into the rear interchangeable foot 21;

- the clip of the carriage 6 is turned on to set the rear end of the roll and the position of the strip is fixed;

- high pressure is supplied to the hydraulic cylinder of the scissors 13 and the end of the roll is trimmed. At the time of cutting, the clamping bar 16 maintains contact with the strip, compressing the spring 17, and since the axis of the scissors lever is located above the cutting line, the cut starts from the edge of the strip farthest from the axis and the resulting tangential forces press the strip against the back centering foot;

- after completion of the cut, the upper knife 11 rises to the upper position;

- the transport carriage for installing the rear end of the roll 6 transfers the strip from the cutting position to the welding position;

- the strip is clamped with an electrode-sponge 4 of the movable bed of the machine.

This completes the installation of the rear end of the roll. After the task, the front end of the machine also stops at the front end in the scissors area of the welding machine and, upon an operator’s command, its mechanisms begin to work in the sequence described above, except that before the transport carriage 5 moves to the welding position, the cutting unit is retracted by the hydraulic cylinder 8 to the original position. After the ends are installed and both rolls are clamped in the sponges of the welding machine, they are welded and deburred, which are also carried out automatically.

A high degree of automation of the process of joining the rolls limits the influence of the subjective factor and the qualifications of the personnel, ensures reproducibility of the welding results and guarantees the stable operation of the metallurgical unit.

Claims (1)

A flash butt welding machine for predominantly narrow strips up to 150 mm wide in metallurgical units, comprising a movable and fixed bed with clamps, a cutting unit with a device for pressing strips before cutting, as well as mechanisms for centering the ends of strips and movable carriages for transferring them from position cutting to a welding position, characterized in that the clamps are made in the form of an open-type cantilever structure, and the cutting unit is made in the form of a separate block, rigidly connected to a fixed bed, and has The ones that provide the possibility of reciprocating movement of the cutting device perpendicular to the axis of the unit for its extension to the strip when trimming the ends of the rolls and retracting to the initial position during operation of the metallurgical unit, and the cutting tool itself is made in the form of lever alligator shears.

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