A method for trimming strip steel

Abstract

This application discloses a strip trimming method to solve the technical problem of accidents easily occurring during strip trimming operations in cold rolling mills. The strip trimming method includes trimming the edge of the preceding strip using a shearing device. While the distance between the shearing device and the weld is less than or equal to a first target distance, the shearing device moves sequentially at multiple feed rates towards the centerline of the strip's width until the distance between the shearing device and the narrower edge of the preceding and following strips is 10%-15% of the weld width, with the feed rates increasing sequentially. The shearing device then trims the edge of the weld. Finally, the shearing device trims the edge of the following strip, while the distance between the shearing device and the weld is greater than or equal to a second target distance, and the shearing device moves simultaneously away from the centerline of the following strip's width. The trimming method of this application results in less breakage of the trimmed scrap edge and a lower accident rate during the trimming operation.

Description

Technical Field

[0001] This application belongs to the field of strip steel processing technology, specifically relating to a method for trimming strip steel edges. Background Technology

[0002] To control the width and edge quality of the strip steel, shearing devices are often installed after the welding machine in cold rolling mills to trim the edges of the strip steel. Since the strip steel on a cold rolling mill is welded from multiple strips, adjacent strips may differ in width. Therefore, trimming can easily lead to accidents, adversely affecting the continuous, stable operation and safe production of the cold rolling mill. Summary of the Invention

[0003] To address the technical problem of accidents easily occurring during the edge trimming operation of current cold rolling mills, this application provides a method for trimming strip steel.

[0004] In a first aspect of this application, a strip trimming method is provided for trimming the edges of a front strip and a rear strip connected by a weld, the strip trimming method comprising:

[0005] The shearing device cuts the edge of the front strip. Under the condition that the distance between the shearing device and the weld is less than or equal to the first target distance, the shearing device moves in sequence at multiple feed speeds toward the width centerline of the strip while cutting the edge, until the distance between the shearing device and the edge of the narrower strip in the front and rear strips is 10%-15% of the strip width, and the multiple feed speeds increase in sequence.

[0006] The weld seam is trimmed using the shearing device;

[0007] The shearing device cuts the edge of the strip at the rear. When the distance between the shearing device and the weld is greater than or equal to the second target distance, the shearing device moves away from the width centerline of the strip at the same time as cutting the edge.

[0008] In some embodiments, the shearing device moves sequentially toward the width centerline of the strip at two feed rates while shearing the edge, wherein the first feed rate is 3.5-4 mm / s and the second feed rate is 6-8 mm / s.

[0009] In some embodiments, the shearing device moves at a feed rate of 6-8 mm / s for 1-2 seconds, and the running speed of the front strip is 500 m / min.

[0010] In some embodiments, the feed rates are increased sequentially to make the scrap width at the first 10 mm of the weld greater than 8 mm.

[0011] In some embodiments, the tangential width of the weld is positively correlated with the difference between the width of the preceding strip and the target width of the preceding strip.

[0012] In some embodiments, the step of trimming the weld edge by the shearing device includes the shearing line of the shearing device being straight and the length of the shearing line being less than 20 mm.

[0013] In some embodiments, when the distance between the shearing device and the weld is greater than or equal to the second target distance, the shearing device moves sequentially at multiple exit speeds away from the width centerline of the subsequent strip while shearing the edge, and the multiple exit speeds decrease sequentially.

[0014] In some embodiments, the shearing device moves sequentially at two exit speeds away from the width centerline of the rear strip while cutting the edge, wherein the first exit speed is 6-8 mm / s and the second exit speed is 3.5-4 mm / s.

[0015] In some embodiments, the multiple cutter exit speeds are successively reduced so that the scrap edge width at 10 mm after the weld is greater than 8 mm.

[0016] In some embodiments, the speed at which the shearing device moves toward the width centerline of the strip is positively correlated with the difference between the width of the subsequent strip and the target width of the subsequent strip.

[0017] The strip trimming method provided according to one or more embodiments of this application enables the shearing device to have multiple feed speeds, such that at least one feed speed near the center line of the strip width is greater than the feed speed near the edge of the strip. When the strip moving speed on the cold rolling mill remains constant, the shearing line on the strip will bend or bend towards the center line of the strip width. Compared to a straight shearing line, the successive increase of the multiple feed speeds will make the weld width on the trimmed scrap edge wider, and the strip width in front of the weld relatively wider. This not only makes the weld on the scrap edge less prone to breakage, but also reduces the accident rate of the trimming operation, and reduces the amount of strip cut, thus reducing waste. Attached Figure Description

[0018] Figure 1 A schematic flowchart of a strip shearing method in one or more embodiments of this application is shown.

[0019] Figure 2 A schematic diagram of the shearing traces of the strip shearing method in one or more embodiments of this application is shown.

[0020] Explanation of reference numerals in the attached drawings: 11-front strip, 12-rear strip, 13-weld, 14-shearing mark. Detailed Implementation

[0021] To enable those skilled in the art to more clearly understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] The strip steel on the cold rolling mill is welded from adjacent front strip steel and rear strip steel. The adjacent strip steel has a difference in width. When the shearing device cuts the weld seam, the width of the scrap edge cut off on one or both sides of the strip steel is narrower. The weld seam of the scrap edge is subjected to greater stress, and the weld seam of the scrap edge will be prone to breakage, which will lead to the accumulation of scrap edges and affect the operation of the edge cutting.

[0023] Please see Figure 1 and Figure 2 This application provides a strip trimming method for trimming the edges of a front strip 11 and a rear strip 12 connected by a weld 13. The strip trimming method includes the following steps.

[0024] Step S100: The shearing device cuts the edge of the front strip 11. Under the condition that the distance between the shearing device and the weld 13 is less than or equal to the first target distance, the shearing device moves in sequence at multiple feed speeds toward the width centerline of the strip while cutting the edge, until the distance between the shearing device and the edge of the narrower strip 11 and the rear strip 12 is 10%-15% of the width of the weld 13, and the multiple feed speeds increase in sequence.

[0025] Based on the direction of strip movement, the strip in front of weld 13 is the front weld 13, and the strip behind weld 13 is the rear strip 12. The edge trimming operation trims the edges of both the front strip 11 and the rear strip 12 so that the width of both the front strip 11 and the rear strip 12 meets the requirements.

[0026] As the strip moves, the uncut weld seam 13 will gradually approach the shearing device. The shearing device moves towards the center line of the strip, so the shearing line 14 on the strip will also move towards the center line of the strip width, and the width of the cut waste edge will gradually become wider.

[0027] The shearing device moves sequentially at multiple feed speeds, with the feed speeds increasing in sequence. Understandably, at least one feed speed near the center line of the strip width is greater than the feed speed near the edge of the strip. With the strip moving at a constant speed on the cold rolling mill, the shearing marks 14 on the strip will bend or bend towards the center line of the strip width. Compared to straight shearing marks 14, the sequential increase in feed speeds will make the weld 13 on the scrap edge wider, and the strip width in front of the weld 13 will be relatively wider. Not only is the weld 13 on the scrap edge less likely to break, but the amount of strip cut is also less, which can reduce waste.

[0028] The value of the first target spacing can be set by the values ​​of multiple feed speeds of the needle and the width of the front strip 11. When the values ​​of multiple feed speeds are all large, the value of the first target spacing can be relatively small, and the shearing line 14 is relatively steep. When the values ​​of multiple feed speeds are all small, the value of the first target spacing can be relatively large, and the shearing line 14 is relatively gentle. This ensures that the distance between the shearing device and the narrower side of the front strip 11 and the rear strip 12 is 10%-15% of the width of the weld 13, thereby ensuring that the weld 13 on the scrap edge has sufficient width. Of course, the distance between the shearing device and the narrower side of the front strip 11 and the rear strip 12 can be 11%, 12%, 13%, 14%, etc., of the width of the weld 13.

[0029] Step S200: Trim the edges of weld 13 using a shearing device.

[0030] Step S300: The shearing device cuts the edge of the rear strip 12. When the distance between the shearing device and the weld 13 is greater than or equal to the second target distance, the shearing device moves away from the width centerline of the rear strip 12 while cutting the edge, until the shearing device moves to the set position to continue the edge cutting operation.

[0031] After the shearing device completes the shearing of weld 13, the shearing device moves away from the width centerline of the rear strip 12. This makes the width of weld 13 on the sheared scrap steel the widest, that is, the area under stress at weld 13 increases, which can reduce the stress at weld 13 and reduce the possibility of the scrap edge breaking at weld 13.

[0032] Under the condition that the distance between the shearing device and the weld 13 is greater than or equal to the second target distance, the shearing device moves further away from the width centerline of the strip 12 to ensure that the weld 13 of the scrap edge cut off has a wider width.

[0033] In the cold rolling mill, the width of the strip after the edge trimming operation needs to reach a set value so that the width of the finished strip meets the customer's requirements. Therefore, in the edge trimming operation, two shearing devices are generally used to trim the two sides of the strip respectively. The distance between the two shearing devices is the set value. When the distance between one of the shearing devices and the center line of the width of the rear strip 12 is greater than or equal to half of the set value, the speed of the shearing device drops to 0. That is, the shearing device no longer moves away from the center line of the rear strip 12 and continues to trim the strip.

[0034] This application provides multiple feed rates to change the shearing trace 14 at the weld 13 during the cutting action, which not only makes the weld 13 on the scrap edge wider, but also reduces the amount of strip steel wasted.

[0035] In some embodiments, the shearing device moves sequentially toward the width centerline of the strip at two feed rates while shearing the edge, wherein the first feed rate is 3.5-4 mm / s and the second feed rate is 6-8 mm / s.

[0036] Both the first and second target spacings can be obtained using infrared scanning equipment or existing equipment on the cold rolling mill. With the strip's moving speed constant, the shearing device moves towards the centerline of the width of the preceding strip 11 at one feed speed and then at another feed speed. The shearing trace 14 will then be a zigzag shape. While meeting the requirement of a wider weld 13 on the scrap edge, the shearing device only needs to perform one speed change, making operation simple. The first feed speed is 3.5-4 mm / s, and the second feed speed is 6-8 mm / s. The difference between the two feed speeds is small, making it less likely for shearing defects to occur in the preceding strip 11.

[0037] Specifically, in some embodiments, the width of the front strip 11 and the rear strip 12 is 700-1200 mm, and the thickness is 0.12-0.55 mm. The running speed of the front strip 11 is 500 m / min, and the shearing device moves at a feed speed of 6-8 mm / s for 1-2 seconds. This ensures that the feed speeds increase sequentially so that the scrap edge width in the first 10 mm of the weld 13 is greater than 8 mm, guaranteeing that the scrap edge has a suitable width and is less likely to break at the weld due to an excessively narrow scrap edge, thus reducing the accident rate caused by scrap edge breakage.

[0038] Specifically, the first feed rate can be selected as 3.6mm / s, 3.7mm / s, 3.8mm / s, 3.9mm / s, etc., and the second feed rate can be selected as 6.5mm / s, 7mm / s, 7.5mm / s, etc.

[0039] Of course, in other embodiments, the shearing device has the same acceleration as it moves toward the centerline of the width of the front strip 11. In this case, the shearing device has multiple feed rates, and the shearing trace 14 will be arc-shaped with few sharp edges.

[0040] In some embodiments, the tangential width of the weld is positively correlated with the difference between the width of the preceding strip 11 and the target width of the preceding strip 11.

[0041] That is, when the shearing device does not move towards the centerline of the width of the front strip 11, the width of the scrap edge cut off from the front strip 11 is positively correlated with the width of the weld 13 on the scrap edge. For example, when the difference between the front strip 11 and the target width of the front strip 11 is 10mm, that is, when the distance between the shearing device and the edge of the front strip 11 is 5mm, the cut edge width of the weld 13 of a scrap edge can be 10mm; when the difference between the front strip 11 and the target width of the front strip 11 is 20mm, that is, when the distance between the shearing device and the edge of the front strip 11 is 10mm, the cut edge width of the weld 13 of a scrap edge can be 15-20mm.

[0042] In some embodiments, the step of cutting the weld 13 edge by a shearing device includes the shearing line 14 of the shearing device being straight and the length of the shearing line 14 being less than 20 mm.

[0043] When the shearing device shears weld 13, the shearing line 14 is straight, making it less likely for the shearing device to affect weld 13, thus reducing the possibility of breakage of the strip or scrap at weld 13. Furthermore, the length of the shearing line 14 being less than 20mm ensures that the scrap weld 13 has a relatively long front and rear section, which also improves the strength of the scrap weld 13 to some extent.

[0044] In some embodiments, when the distance between the shearing device and the weld 13 is greater than or equal to the second target distance, the shearing device moves sequentially at multiple exit speeds away from the width centerline of the rear strip 12 while shearing the edge, and the multiple exit speeds decrease sequentially.

[0045] The shearing device moves sequentially at multiple exit speeds, with the exit speeds decreasing sequentially. Understandably, at least one exit speed near the centerline of the width of the rear strip 12 is greater than the exit speed near the edge of the strip. With the strip moving at a constant speed on the cold rolling mill, the shearing marks 14 on the rear strip 12 will bend or bend towards the centerline of the width of the rear strip 12. Compared to straight shearing marks 14, the sequential decrease in exit speeds will make the width of the rear strip 12 behind the weld 13 wider than that of straight shearing marks 14. This not only makes the weld 13 on the scrap edge less prone to breakage, but also reduces the amount of strip cut, thus reducing waste.

[0046] In some embodiments, the shearing device moves sequentially at two exit speeds away from the width centerline of the rear strip 12 while cutting the edge, wherein the first exit speed is 6-8 mm / s and the second exit speed is 3.5-4 mm / s.

[0047] With the strip moving at a constant speed, the shearing device moves towards the centerline of the width of the rear strip 12 at one exit speed and then at another exit speed. The shearing mark 14 will then be a zigzag shape. While meeting the requirement of a wider weld 13 on the scrap edge, the shearing device only needs to change speed once, making operation simple. The first exit speed is 6-8 mm / s, and the second exit speed is 3.5-4 mm / s. The difference between the two exit speeds is small, making it less likely for shearing defects to occur in the rear strip 12.

[0048] Specifically, in some embodiments, the width of the front strip 11 and the rear strip 12 is 700-1200mm, and the thickness is 0.12-0.55mm. The running speed of the front strip is 500m / min, and the shearing device moves at a cutting speed of 6-8mm / s for 1-2s. This ensures that the cutting speed decreases sequentially so that the scrap edge width at 10mm after the weld 13 is greater than 8mm, guaranteeing that the scrap edge has a suitable width and is less likely to break at the weld due to excessively narrow scrap edge, thus reducing the accident rate caused by scrap edge breakage. Specifically, the first cutting speed can be selected as 6.5mm / s, 7mm / s, or 7.5mm / s, and the second cutting speed can be selected as 3.6mm / s, 3.7mm / s, 3.8mm / s, or 3.9mm / s, etc.

[0049] Of course, in other embodiments, the shearing device has the same acceleration as it moves toward the center line of the width of the strip. In this case, the shearing device has multiple cut speeds, and the shearing trace 14 will be arc-shaped with few sharp edges.

[0050] In some embodiments, the method further includes step S110: obtaining the width of the front strip 11 on the front side of the weld 13 and the rear strip 12 on the rear side of the weld 13.

[0051] Step S120: Obtain the target tangential width of the weld 13 of the strip steel.

[0052] Step S130: Determine multiple cut speeds based on the first target spacing and the obtained target cutting edge width.

[0053] The width of the front strip 11 and the width of the rear strip 12 can be obtained by setting measuring equipment on the cold rolling mill. The measuring equipment can be a laser width measuring instrument or an infrared width measuring instrument, etc.

[0054] The target width of the strip steel is determined by the requirements of the produced strip steel products and is known. After obtaining the widths of the strip steel 11 before weld 13 and the strip steel 12 after weld 13, the width of the scrap edge to be cut off by the shearing device can be determined. When the width of the scrap edge to be cut off is wider, the weight of the scrap edge cut off is heavier. Therefore, the target cutting edge width of weld 13 of the strip steel is wider, so as to reduce the stress of weld 13 on the scrap edge and reduce the possibility of the scrap edge breaking at weld 13. The width of weld 13 on the scrap edge cut by the shearing device can be wider by increasing the first target spacing and / or increasing the exit speed, that is, the target cutting edge width of weld 13 of the strip steel is wider.

[0055] In the cold rolling mill, there are situations where the front strip 11 and the rear strip 12 need to meet different product requirements, that is, the target width of the strip is different. Therefore, by making the target shear width of the weld 13 positively correlated with the width of the front strip 11 and the difference between the target width of the front strip 11, the width of the weld 13 on the scrap edge is ensured, and the weld 13 is not prone to cracking due to the stress of the scrap edge that is sheared off from the front strip 11.

[0056] In some embodiments, the speed at which the shearing device moves toward the width centerline of the strip is positively correlated with the difference between the width of the rear strip 12 and the target width of the rear strip 12.

[0057] Understandably, the position where the weld 13 is sheared is determined through step S100. Thus, by making the cutting speed of the shearing device positively correlated with the difference between the width of the subsequent strip 12 and the target width of the subsequent strip 12, the shape of the scrap edge of the subsequent strip 12 is changed, thereby reducing the influence of the scrap edge of the subsequent strip 12 on the weld 13.

[0058] Specifically, when the difference between the width of the rear strip 12 and the target width of the rear strip 12 is large, the shearing amount of the rear strip 12 is large, and the weight of the scrap edge of the rear strip 12 is large. By increasing the exit speed, the shearing line 14 of the shearing device is made steeper, which can reduce the weight of the scrap edge of the rear strip 12. When the difference between the width of the rear strip 12 and the target width of the rear strip 12 is small, the shearing device is closer to the edge of the rear strip 12. By reducing the exit speed, the shearing line 14 of the shearing device is made gentler, the stress of the shearing device on the edge of the rear strip 12 is low, and the strip edge is less prone to deformation that affects the quality of the strip due to stress.

[0059] In some embodiments, the shearing device is a disc shear. The feed and discharge speeds of the disc shear are easier to control, which is beneficial for the smooth progress of the cutting operation.

[0060] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0061] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0062] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0063] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0064] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the scope and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A method of trimming a strip of steel, characterized in that, A method for trimming the strip edges of a front strip and a rear strip connected by a weld seam, the strip trimming method comprising: The shearing device cuts the edge of the front strip. Under the condition that the distance between the shearing device and the weld is less than or equal to the first target distance, the shearing device moves in sequence at multiple feed speeds towards the width centerline of the strip while cutting the edge, until the distance between the shearing device and the edge of the narrower strip in the front and rear strips is 10%-15% of the weld width, and the multiple feed speeds increase in sequence. The weld seam is trimmed using the shearing device; The shearing device cuts the edge of the strip at the rear. When the distance between the shearing device and the weld is greater than or equal to the second target distance, the shearing device moves away from the width centerline of the strip at the same time as cutting the edge.

2. The strip-sideling method according to claim 1, characterized in that, While cutting the edge, the shearing device moves sequentially towards the width centerline of the strip at two feed speeds, wherein the first feed speed is 3.5-4 mm / s and the second feed speed is 6-8 mm / s.

3. The strip-sideling method according to claim 1, characterized in that, The shearing device moves at a feed rate of 6-8 mm / s for 1-2 seconds, and the running speed of the front strip is 500 m / min.

4. The strip-sideling method according to claim 1, characterized in that, The feed rates are increased sequentially to make the scrap edge width at the first 10mm of the weld greater than 8mm.

5. The strip-sideling method according to claim 1, wherein The tangential width of the weld is positively correlated with the difference between the width of the preceding strip and the target width of the preceding strip.

6. The strip-sideling method according to claim 4, wherein The step of cutting the weld edge using the shearing device includes the following: the shearing line of the shearing device is straight, and the length of the shearing line is less than 20 mm.

7. The strip-sideling method according to claim 1, wherein When the distance between the shearing device and the weld is greater than or equal to the second target distance, the shearing device moves sequentially away from the width centerline of the strip at multiple cutting speeds while cutting the edge, and the multiple cutting speeds decrease sequentially.

8. The strip-sideling method according to claim 7, characterized in that, While cutting the edge, the shearing device moves sequentially at two exit speeds in a direction away from the width centerline of the rear strip, wherein the first exit speed is 6-8 mm / s and the second exit speed is 3.5-4 mm / s.

9. The strip-sideling method according to claim 7, characterized in that, The cutting speeds of the multiple cutters are successively reduced so that the width of the scrap edge 10mm after the weld is greater than 8mm.

10. The strip-sideling method of claim 1 wherein, The speed at which the shearing device moves toward the width centerline of the strip is positively correlated with the difference between the width of the subsequent strip and the target width of the subsequent strip.

Images