A method for improving the welding quality of a laser welding machine by using a thickness gauge

Abstract

The application discloses a method for improving welding quality of a laser welding machine by using a thickness gauge, and the welding quality is improved by using a thickness gauge arranged in front of the laser welding machine, using the actual thickness of front and rear strip steels measured by the thickness gauge to perform real-time height centering adjustment, and then performing welding, wherein the welding includes welding by using welding parameters corresponding to the actual thickness and welding by using welding parameters corresponding to a set thickness; the head and tail thickness data measured by the thickness gauge are used for height centering of the welding machine, so that the center line of the strip steel is ensured to be consistent even if the raw material has thickness deviation, the re-welding rate can be obviously reduced, and the operation efficiency of the unit is improved.

Description

Technical Field

[0001] This invention belongs to the field of cold rolling technology, and specifically relates to a method for improving the welding quality of laser welding machines using a thickness gauge. Background Technology

[0002] Laser welding machines are crucial equipment in cold rolling mills. Their main function is to weld the ends of adjacent strip steel coils after the ends have been cut together by a shearing machine, thus ensuring continuous production. The key parameters of laser welding machines are welding time and weld quality. The welding time directly affects the production efficiency of the cold rolling production line, while the weld quality directly impacts the normal and stable operation of the cold rolling production line.

[0003] The current welding method is to perform welding operations based on the thickness information transferred by hot rolling. The height alignment operation during welding is carried out using the thickness transferred by hot rolling. Due to the hot rolling process, there will be thickness fluctuation deviations, which can easily lead to height differences after alignment, affecting the welding quality and thus affecting the unit's production rhythm. Summary of the Invention

[0004] The purpose of this invention is to provide a method for improving the welding quality of laser welding machines by using a thickness gauge. When positioning the thickness at the beginning and end of the strip, the thickness gauge at the entrance is used to apply the actual thickness data of the beginning and end to the height of the welding machine to achieve real-time centering, ensuring that the center line of the strip remains consistent even if there is a thickness deviation.

[0005] Therefore, the present invention adopts the following technical solution:

[0006] A method for improving the welding quality of a laser welding machine using a thickness gauge includes the following steps: 1) A thickness gauge is installed in front of the laser welding machine. The thickness gauge is used to measure the thickness of the front and rear strip heads and tails. The thickness of the front strip is recorded as H and the thickness of the rear strip is recorded as h. The actual thickness data is read and transmitted to the welding machine, overwriting the original hot-rolled thickness information. The absolute value of the difference between the actual thicknesses of the front and rear strips is Δh = (|front strip thickness H - rear strip thickness h|) / 2;

[0007] 2) The trolley of the welding machine is equipped with two sets of side guide wheels located on the underside of the strip steel. These are the inlet side guide wheel and the outlet side guide wheel. The inlet side guide wheel is fixed at a horizontal height and transmits the actual thickness difference data Δh to the servo motor of the hydraulic cylinder. The insertion amount of the wedge is adjusted by the hydraulic servo motor, and the height of the outlet side guide wheel is adjusted to make the center lines of the thickness of the strip steel in the front and rear rows consistent before welding is performed.

[0008] Preferably, the above welding includes welding with welding parameters corresponding to the actual thickness and welding with welding parameters corresponding to the set thickness.

[0009] During the welding process, the guide rollers clamp the ends of the strip steel and roll them as the welding machine moves. This ensures that both ends of the strip steel are correctly positioned on the same horizontal plane, guaranteeing welding quality.

[0010] The welding process includes: when the actual thickness of the front and rear strips differs significantly from the set thickness, a change in the welding grade corresponding to the actual thickness occurs, resulting in changes in the welding parameters. A thickness gauge is used to measure the thickness of the front and rear strips for height alignment adjustment, and the welding parameters corresponding to the actual thickness are then adopted. Alternatively, if the actual thickness of the front and rear strips differs greatly from the set thickness, the changes in welding parameters may not match the actual material, affecting welding quality. In this case, a thickness gauge is used to measure the thickness of the front and rear strips for height alignment adjustment, and welding is performed using the welding parameters corresponding to the set thickness.

[0011] Preferably, the above method is applied to production lines including pickling or acid rolling and other production lines that use laser welding.

[0012] The beneficial effects of this invention are as follows:

[0013] This invention relates to a method for improving the welding quality of laser welding machines using a thickness gauge. By applying a thickness gauge at the weld inlet, the measured data is used to set welding parameters. Specifically, the actual thickness of the strip at the head and tail, as measured by the thickness gauge, is used to adjust the height alignment during welding (strip head thickness - subsequent strip head thickness, strip tail thickness - preceding strip tail thickness). By adjusting the height of the guide roller on the side with the smaller thickness, the center lines of the preceding and following strip thicknesses are aligned for welding. This avoids the impact of thickness fluctuations during hot rolling and tail-waving processes on height alignment during welding. The re-welding rate is significantly reduced, decreasing from 2.5% at the beginning of the year to 0.5%. This significantly improves unit operating efficiency, ensures stable quality, and increases production capacity. Attached Figure Description

[0014] Figure 1 This is a schematic diagram showing the usage position of the thickness gauge of this invention;

[0015] Figure 2 This is a schematic diagram of the height adjustment device of the laser welding machine of the present invention;

[0016] Among them: 1-laser welding machine, 2-thickness gauge, 3-entry uncoiler, 4-entry guide wheel, 5-exit guide wheel, 6-wedge, 7-height adjustment device, 8-hydraulic cylinder. Detailed Implementation

[0017] The following detailed description, through specific embodiments, further illustrates the implementation of the technical solution described herein. These embodiments are intended to provide a detailed description of the technical solution and are not intended to limit the scope of the technical solution. All other embodiments obtained by those skilled in the art based on the embodiments described herein without inventive effort are within the scope of protection of this description.

[0018] Example 1

[0019] This embodiment takes the Zhanjiang Iron and Steel 2030 cold rolling mill as an example.

[0020] A method for improving the welding quality of laser welding machines using a thickness gauge specifically includes the following steps:

[0021] like Figure 1 As shown, a thickness gauge 2 is set in front of the laser welding machine 1 to measure the thickness of the head and tail of the strip. The obtained thickness data is used for setting welding parameters.

[0022] (1) The actual thickness of the front and rear strips measured by the front thickness gauge of the laser welding machine: the thickness of the front strip is recorded as H and the thickness of the rear strip is recorded as h. The absolute value of the difference between the two thicknesses, Δh (H>h / H<h), is calculated. Δh=(|front strip thickness H-rear strip thickness h|) / 2. The actual thickness data is read and transmitted to the welding machine to cover the original hot-rolled thickness information.

[0023] (2) Figure 2 As shown, the welding machine carriage is equipped with two sets of side guide wheels located on the underside of the strip steel. These are the inlet side guide wheel 4 and the outlet side guide wheel 5. The inlet side guide wheel 4 is fixed at a horizontal height and transmits the actual thickness difference data Δh to the servo motor of the hydraulic cylinder 8. The insertion amount of the wedge 7 is adjusted by the hydraulic servo motor, and the height of the outlet side guide wheel 5 is adjusted to make the center lines of the thickness of the strip steel in the front and rear rows consistent.

[0024] (3) Different welding methods are used:

[0025] Mode 1: The thickness of the front and rear strip steel is measured using a thickness gauge, the height is adjusted for centering, and welding is performed using the actual thickness welding parameters;

[0026] Mode 2: The thickness of the front and rear strips is measured using a thickness gauge, the height is adjusted for centering, and welding is performed using the set thickness welding parameters.

[0027] The re-welding rate of the 2030 pickling continuous rolling mill at Zhanjiang Iron and Steel in 2022 was statistically analyzed, and the results are shown in Table 1:

[0028] Table 1. Re-welding rate of Zhanjiang Iron and Steel's 2030 cold rolling mill in 2022

[0029] January February March April May June July August September October November December Number of re-weldings 196 74 50 131 78 58 47 50 46 45 37 23 Re-welding rate % 2.5 0.9 0.6 1.6 1 0.7 0.6 0.5 0.64 0.62 0.51 0.32

[0030] In Table 1, the re-welding rate for January is the re-welding rate using the hot-rolled thickness transfer welding method, and the re-welding rate for February to December is the re-welding rate after applying the method of the present invention.

[0031] As can be seen, the method of this invention can significantly reduce the re-welding rate. Using this method, 2.556 hours of production time can be saved per month, increasing monthly output by approximately 766 tons and annual output by approximately 9200 tons. Therefore, the method of this invention significantly improves the unit's operating efficiency and plays a significant role in ensuring stable quality and maximizing output.

[0032] Although embodiments of the present description have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present description, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for improving the welding quality of a laser welding machine using a thickness gauge, characterized in that, The steps include: 1) A thickness gauge is installed in front of the laser welding machine. The thickness gauge is used to measure the thickness of the front and rear strip heads and tails. The thickness of the front strip is recorded as H and the thickness of the rear strip is recorded as h. The actual thickness data is read and transmitted to the welding machine to overwrite the original hot-rolled thickness information. The absolute value of the difference between the actual thickness of the front and rear strips is △h=(|front strip thickness H-rear strip thickness h|) / 2; 2) The trolley of the welding machine is equipped with two sets of side guide wheels located on the lower side of the strip steel. These are the inlet side guide wheel and the outlet side guide wheel. The inlet side guide wheel is fixed at a horizontal height and transmits the actual thickness difference data Δh to the servo motor of the hydraulic steel. The insertion amount of the wedge is adjusted by the hydraulic servo motor, and the height of the outlet side guide wheel is adjusted so that the center lines of the thickness of the strip steel in the front and rear are consistent. 3) When the actual thickness of the strip in the front and rear rows differs significantly from the set thickness, i.e. the welding grade corresponding to the actual thickness changes, the welding parameters also change. Use a thickness gauge to measure the thickness of the strip in the front and rear rows for height centering adjustment, and then use the welding parameters corresponding to the actual thickness. Or, when the actual thickness of the strip in the front and rear rows differs greatly from the set thickness, the changes in welding parameters do not match the actual material, affecting the welding quality. Use a thickness gauge to measure the thickness of the strip in the front and rear rows for height centering adjustment, and then use the welding parameters corresponding to the set thickness for welding. The laser welding machine is used in a cold rolling continuous rolling production line.

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