Control method and adjusting device for preventing turning patterns of six-roller cold rolling mill

Abstract

The invention relates to a control method for preventing turning lines of a six-roller cold-rolling mill, which comprises the following steps of: (1) when the cold-rolling mill adjusts a rolling line, placing a cushion block between working roller seats on the same side of an upper working roller and a lower working roller to ensure that single-side roller surfaces of the upper working roller and the lower working roller are not pressed firstly; the cushion block is taken out after the rolling line is adjusted; (2) completing calibration and warm roller operation of a working roller; (3) controlling a roll gap pressing process: setting a normal pressing gradient of the roll gap; when the roll gap is larger than 5000 microns, the pressing gradient is a normal pressing gradient; when the roll gap is 3000-5000 [mu] m, the pressing gradient is half of the normal pressing gradient; when the roll gap reaches the target value from 3000 microns, the pressing gradient is one third of the normal pressing gradient; and (4) tension building and vehicle starting process control. And turning marks are reduced or eliminated, and the surface quality of products is improved.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum cold rolling, in particular to a control method and an adjustment device for preventing wheel streaking on a six-roller cold rolling mill. Background Art

[0002] In the existing six-roll aluminum cold rolling mill, due to improper bending roll control when adjusting the rolling line after the working roll is replaced, the roll gap pressing rate is too fast, and the tension control at the start is unreasonable, it is easy to form rolling marks on the strip surface, affecting product quality. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a control method and adjustment device for preventing wheel streaks on a six-roll cold rolling mill, so as to reduce or eliminate wheel streaks and improve the surface quality of the product.

[0004] The present invention is implemented by the following scheme: A control method for preventing wheel streaks on a six-roll cold rolling mill, comprising the following steps: (1) when the cold rolling mill adjusts the rolling line, a pad is placed between the working roll seats on the same side of the upper and lower working rolls to ensure that the upper and lower working rolls do not have a single-side roll surface pressed first; after completing the adjustment of the rolling line, the pad is removed; (2) the calibration of the working rolls and the warm roll operation are completed; (3) the roll gap pressing process control: setting the normal pressing gradient of the roll gap; when the roll gap is greater than 5000um, the pressing gradient is the normal pressing gradient; when the roll gap is between 3000 and 5000um, the pressing gradient is half of the normal pressing gradient; when the roll gap is from 3000um to the target value, the pressing gradient is one-third of the normal pressing gradient; (4) the tension establishment and starting process control: setting the normal tension increase gradient, the outlet target total tension and the inlet target total tension; within the first 5s of the tension establishment, the increase gradient of the outlet tension and the inlet tension are both half of the normal increase gradient, and if it exceeds After 5s, the increasing gradients of the outlet tension and the inlet tension are restored to the normal increasing gradients; (5) If the inlet target total tension in step (4) is greater than 10KN, the working roll is started when the outlet tension and the inlet tension reach half of the inlet target total tension, and the outlet tension and the inlet tension remain unchanged before the working roll linear speed reaches 10m / min. When the working roll linear speed exceeds 10m / min, the outlet tension and the inlet tension are increased to the outlet target total tension and the inlet target total tension respectively with the normal increasing gradient; (6) If the inlet target total tension in step (4) does not exceed 10KN, the outlet tension and the inlet tension need to be increased to 10KN when the working roll is started, and the outlet tension and the inlet tension remain unchanged at 10KN before the working roll linear speed reaches 10m / min. When the working roll linear speed exceeds 10m / min, the outlet tension and the inlet tension are adjusted to the outlet target total tension and the inlet target total tension respectively.

[0005] Furthermore, in step (3), the normal pressure gradient is 500-700 μm / s; in step (4), the normal tension increase gradient is 15-25 KN / s, and the outlet target total tension is greater than the inlet target total tension.

[0006] Another technical solution of the present invention: a six-roll cold rolling mill adjustment device, including a frame, in which an upper support roll, an upper intermediate roll, an upper working roll, a lower working roll, a lower intermediate roll, and a lower support roll are sequentially arranged in the middle of the frame from top to bottom, and is characterized in that: both ends of the upper and lower support rolls are respectively rotatably connected to a support roll seat that can move up and down relative to the frame, both ends of the upper and lower intermediate rolls are respectively rotatably connected to an intermediate roll seat that can move up and down relative to the frame, and both ends of the upper and lower working rolls are respectively rotatably connected to a working roll seat that can move up and down relative to the frame, and a pad is detachably placed between the working roll seats on the same side of the upper and lower working rolls.

[0007] Furthermore, a pressing cylinder for pushing the support roller seats upward is provided below the support roller seats at both ends of the lower support roller.

[0008] Furthermore, a work roll bending cylinder is provided between the work roll seats of the upper and lower work rolls on the same side.

[0009] Furthermore, upper intermediate roller bending cylinders for pushing the intermediate roller seats upward are provided below the intermediate roller seats at both ends of the upper intermediate roller, and lower intermediate roller bending cylinders for pushing the intermediate roller seats downward are provided above the intermediate roller seats at both ends of the lower intermediate roller.

[0010] Furthermore, support roller balancing cylinders for pushing the support roller seats upward are provided below the support roller seats at both ends of the upper support roller.

[0011] Furthermore, a rolling line adjustment mechanism is provided above the upper support roller.

[0012] Furthermore, the rolling line adjustment mechanism includes a pair of adjusting wedges located above the support roller seats at both ends of the upper support roller, the inclined surfaces of the adjusting wedges are facing downward, the bottom surfaces are flat and abut against the upper side surfaces of the support roller seats, and fixed wedges are fixedly connected to the tops of both sides of the frame, with the inclined surfaces of the fixed wedges facing downward and matching the inclined surfaces of the adjusting wedges.

[0013] Furthermore, a horizontal worm gear screw lift is installed on the middle top of the frame, the screw end of the worm gear screw lift is connected to the adjusting wedge on one side, the input end of the worm gear screw lift is coaxially connected to the main shaft of a hydraulic motor, and the adjusting wedges on both sides are connected together by a connecting beam.

[0014] Compared with the prior art, the present invention has the following beneficial effects: the present invention ensures that when the working roll adjusts the rolling line, the working roll surface will not be pressed on one side first by adding a working roll seat pad, thereby preventing indentations caused by pressing on one side first; by controlling the roll gap pressing process, the present invention prevents pressing too quickly, which causes local rapid collision of the roll surface and the formation of wheel marks; by controlling the tensioning and starting process, the present invention prevents the head from biting in when starting and slipping due to mismatched inlet and outlet tension, thereby preventing wheel marks; ultimately, the present invention achieves the goal of reducing or eliminating wheel marks and improving the surface quality of the product.

[0015] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below through specific embodiments and related drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a partial structural cross-sectional view of a six-roller cold rolling mill according to an embodiment of the present invention; Explanation of the numbers in the figure: 1-frame, 2-upper support roller, 3-upper intermediate roller, 4-upper working roller, 5-lower working roller, 6-lower intermediate roller, 7-lower support roller, 8-support roller seat, 9-intermediate roller seat, 10-working roller seat, 11-pad, 12-pressing cylinder, 13-working roller bending cylinder, 14-upper intermediate roller bending cylinder, 15-lower intermediate roller bending cylinder, 16-support roller balancing cylinder, 17-adjusting wedge, 18-fixed wedge, 19-worm gear and screw lifter, 20-connecting beam. DETAILED DESCRIPTION

[0017] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0019] A control method for preventing wheel streaks on a six-roll cold rolling mill comprises the following steps: (1) when the cold rolling mill adjusts the rolling line, a pad is placed between the working roll seats on the same side of the upper and lower working rolls to ensure that the upper and lower working rolls do not have a single-side roll surface pressed first; after completing the adjustment of the rolling line, the pad is removed; (2) the calibration of the working rolls and the warm roll operation are completed; (3) the roll gap pressing process control: setting the normal pressing gradient of the roll gap; when the roll gap is greater than 5000um, the pressing gradient is the normal pressing gradient; when the roll gap is between 3000 and 5000um, the pressing gradient is half of the normal pressing gradient; when the roll gap is from 3000um to the target value, the pressing gradient is one-third of the normal pressing gradient; (4) the tension establishment and starting process control: setting the normal tension increase gradient, the outlet target total tension and the inlet target total tension; in the first 5s of the tension establishment, the increase gradients of the outlet tension and the inlet tension are both half of the normal increase gradient, and after more than 5s, the outlet tension is The lifting gradients of the force and the inlet tension are restored to the normal lifting gradients; (5) If the inlet target total tension in step (4) is greater than 10KN, the working roll is started when the outlet tension and the inlet tension reach half of the inlet target total tension, and the outlet tension and the inlet tension remain unchanged before the working roll linear speed reaches 10m / min. When the working roll linear speed exceeds 10m / min, the outlet tension and the inlet tension are respectively increased to the outlet target total tension and the inlet target total tension with the normal lifting gradient; (6) If the inlet target total tension in step (4) does not exceed 10KN, the outlet tension and the inlet tension need to be increased to 10KN when the working roll is started, and the outlet tension and the inlet tension remain unchanged at 10KN before the working roll linear speed reaches 10m / min. When the working roll linear speed exceeds 10m / min, the outlet tension and the inlet tension are respectively adjusted to the outlet target total tension and the inlet target total tension.

[0020] According to the different inlet target total tension, with 10KN as the boundary, the starting process of the working roller is carried out in two different ways. When the inlet target total tension does not exceed 10KN, start the roller according to step (6); when the inlet target total tension is greater than 10KN, start the roller according to step (5); the tension of the aluminum strip is controlled by the uncoiler and the winder. The uncoiler controls the inlet tension, and the winder controls the outlet tension.

[0021] By adding work roll seat blocks, we ensure that one side of the work roll surface does not press against the other side first when adjusting the rolling line, thus preventing indentations caused by one side pressing against the other. Controlling the roll gap pressing process prevents excessive pressing, which can cause localized rapid contact on the roll surface and lead to wheel marks. Controlling the tension during the start-up process prevents the head from biting in during start-up due to tension mismatch at the inlet and outlet, leading to slippage and wheel marks. These controls ultimately reduce or eliminate wheel marks and improve product surface quality.

[0022] In this embodiment, in step (3), the normal pressing gradient is 500-700 μm / s; in step (4), the normal tension increase gradient is 15-25 KN / s, and the target total tension at the outlet is greater than the target total tension at the inlet.

[0023] like Figure 1 As shown, a six-roll cold rolling mill adjustment device includes a frame 1. The frame 1 is provided with an upper support roll 2, an upper intermediate roll 3, an upper working roll 4, a lower working roll 5, a lower intermediate roll 6, and a lower support roll 7 in the middle, from top to bottom. The ends of the upper and lower support rolls are respectively rotatably connected to a support roll seat 8 that can move up and down relative to the frame. The ends of the upper and lower intermediate rolls are respectively rotatably connected to an intermediate roll seat 9 that can move up and down relative to the frame. The ends of the upper and lower working rolls are respectively rotatably connected to a working roll seat 10 that can move up and down relative to the frame. A spacer 11 is detachably placed between the working roll seats on the same side (same end) of the upper and lower working rolls. The drive side of the six-roll cold rolling mill is the side where the transmission device that drives the working rolls is located. The two working rolls are transmission-connected to the transmission device on the drive side. The operating side of the six-roll cold rolling mill is the side opposite to the drive side. When adjusting the rolling line (i.e., during the work roll calibration and warming process), the adjustment device of the present invention places a spacer between the work roll seats of the upper and lower work rolls to limit the roll gap on both sides (ends) of the upper and lower work rolls, ensuring that the upper and lower work roll surfaces do not press against one side first, thus preventing indentations caused by one side pressing against the other. After the rolling line adjustment is completed, the spacer is removed. Pad thickness = working roll diameter - working roll seat height + 5mm, ensure the wedge adjustment space margin and smooth adjustment of the wedge. The thickness of the pad ensures that one side of the roll surface will not contact first when adjusting the roll gap.

[0024] In this embodiment, upward-pushing cylinders 12 are located below the support roller seats at both ends of the lower support roller. These cylinders are used to online control the longitudinal and transverse tolerances of the aluminum strip. During the rolling process, these cylinders control changes in the strip's thickness, tension, and rolling speed, ensuring that the longitudinal and transverse tolerances of the rolled aluminum strip remain within target control ranges.

[0025] In this embodiment, a work roll bending cylinder 13 is provided between the work roll seats of the upper and lower work rolls on the same side. The work roll bending cylinder 13 is used to bend the work rolls to improve the shape of the rolled aluminum strip.

[0026] In this embodiment, upper intermediate roll bending cylinders 14 are provided below the intermediate roll seats at both ends of the upper intermediate roll to push the intermediate roll seats upward, while lower intermediate roll bending cylinders 15 are provided above the intermediate roll seats at both ends of the lower intermediate roll to push the intermediate roll seats downward. The upper intermediate roll bending cylinders 14 and the lower intermediate roll bending cylinders 15 are used to bend the upper and lower intermediate rolls, respectively, to improve the shape of the rolled aluminum strip.

[0027] In this embodiment, support roller balancing cylinders 16 for pushing the support roller seats upward are provided below the support roller seats at both ends of the upper support roller. The support roller balancing cylinders 16 are used to balance the upper support roller.

[0028] In this embodiment, a rolling line adjustment mechanism is provided above the upper support roller.

[0029] In this embodiment, the rolling line adjustment mechanism includes a pair of adjusting wedges 17 located above the support roller seats at both ends of the upper support roller, the inclined surfaces of the adjusting wedges are facing upward, the bottom surfaces are flat and abut against the upper side surfaces of the support roller seats, and fixed wedges 18 are fixedly connected to the tops of both sides of the frame, with the inclined surfaces of the fixed wedges facing downward and matching the inclined surfaces of the adjusting wedges.

[0030] In this embodiment, a horizontally mounted worm gear screw lift 19 is mounted at the top center of the frame. The end of the screw of the worm gear screw lift is connected to an adjustment wedge on one side. The input end of the worm gear screw lift is coaxially connected to the main shaft of a hydraulic motor. A connecting beam 20 connects the two adjustment wedges. This rolling line adjustment mechanism uses a hydraulic motor to drive the adjustment wedge via the worm gear screw lift 19. The hydraulic motor drives the worm gear screw lift via a coupling. The screw of the worm gear screw lift drives the adjustment wedge on one side to move horizontally (and simultaneously drives the adjustment wedge on the other side to move synchronously via the connecting beam) to achieve adjustment. The rolling line adjustment mechanism is primarily used to compensate for rolling height after roller grinding. It has a simple and compact structure and safe and reliable performance.

[0031] The six-roller cold rolling mill adjustment device only records the local structure of the six-roller cold rolling mill, which is used to implement some steps (mainly steps (1) and (3)) in the above-mentioned six-roller cold rolling mill prevention method. The rest of the six-roller cold rolling mill structure (such as the transmission device of the working roll, etc.) is not mentioned, and all of them are existing technologies for six-roller cold rolling mills.

[0032] Unless otherwise stated, for any of the technical solutions disclosed in the present invention, if a numerical range is disclosed, the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is merely a numerical range that is representative or has a more obvious technical effect among many feasible numerical values. Due to the large number of numerical values, it is impossible to enumerate them exhaustively. Therefore, the present invention discloses some numerical values ​​to illustrate the technical solutions of the present invention. Moreover, the numerical values ​​listed above should not be construed as limiting the scope of protection of the present invention.

[0033] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by integral molding using a casting process) (except where it is obviously not possible to use an integrated molding process).

[0034] In addition, unless otherwise stated, the terms used in any technical solution disclosed in the present invention to express positional relationships or shapes include states or shapes that are approximate, similar, or close thereto.

[0035] Any component provided by the present invention may be assembled from multiple separate components, or may be a separate component manufactured by an integral molding process.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other manner. Any person skilled in the art may utilize the above-disclosed technical content to modify or modify the present invention into equivalent embodiments. However, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the technical content of the present invention and are based on the technical essence of the present invention remain within the scope of protection of the present invention.

Claims

1. A method for preventing wheel streaking in a six-roll cold rolling mill, characterized in that: The following steps are involved: (1) When the cold rolling mill adjusts the rolling line, a pad is placed between the working roll seats on the same side of the upper and lower working rolls to ensure that the upper and lower working rolls do not press against one side first; remove the pad after completing the adjustment of the rolling line; (2) Complete the calibration of the working rolls and the warm roll operation; (3) Roll gap pressing process control: set the normal pressing gradient of the roll gap; when the roll gap is greater than 5000um, the pressing gradient is the normal pressing gradient; when the roll gap is between 3000 and 5000um, the pressing gradient is half of the normal pressing gradient; when the roll gap is from 3000um to the target value, the pressing gradient is one-third of the normal pressing gradient; (4) Construction and start-up process control: set the normal tension increase gradient, the outlet target total tension and the inlet target total tension; in the first 5s of construction, the outlet tension and inlet tension increase gradients are both half of the normal increase gradient, and after more than 5s, the outlet tension and inlet tension increase gradients are both Return to the normal lifting gradient; (5) If the inlet target total tension in step (4) is greater than 10KN, the working roll is started when the outlet tension and the inlet tension reach half of the inlet target total tension, and the outlet tension and the inlet tension remain unchanged before the working roll linear speed reaches 10m / min. When the working roll linear speed exceeds 10m / min, the outlet tension and the inlet tension are increased to the outlet target total tension and the inlet target total tension respectively with the normal lifting gradient; (6) If the inlet target total tension in step (4) does not exceed 10KN, the outlet tension and the inlet tension need to be increased to 10KN when the working roll is started, and the outlet tension and the inlet tension remain unchanged at 10KN before the working roll linear speed reaches 10m / min. When the working roll linear speed exceeds 10m / min, the outlet tension and the inlet tension are adjusted to the outlet target total tension and the inlet target total tension respectively.

2. The method for preventing wheel streaking in a six-high cold rolling mill according to claim 1, wherein: In step (3), the normal pressure gradient is 500~700μm / s; in step (4), the normal tension increase gradient is 15~25KN / s, and the outlet target total tension is greater than the inlet target total tension.

3. A six-roller cold rolling mill adjustment device, comprising a frame, wherein an upper support roll, an upper intermediate roll, an upper working roll, a lower working roll, a lower intermediate roll, and a lower support roll are sequentially arranged in the middle of the frame from top to bottom, characterized in that: The two ends of the upper and lower support rollers are respectively rotatably connected to the support roller seats that can move up and down relative to the frame. The two ends of the upper and lower intermediate rollers are respectively rotatably connected to the intermediate roller seats that can move up and down relative to the frame. The two ends of the upper and lower working rollers are respectively rotatably connected to the working roller seats that can move up and down relative to the frame. A detachable pad is placed between the working roller seats on the same side of the upper and lower working rollers.

4. The anti-indentation adjustment device for a six-roller cold rolling mill according to claim 3, characterized in that: A pressing cylinder for pushing the support roller seat upwards is provided below the support roller seat at both ends of the lower support roller.

5. The anti-indentation adjustment device for a six-roller cold rolling mill according to claim 3, characterized in that: A working roll bending cylinder is provided between the working roll seats of the upper and lower working rolls on the same side.

6. The anti-indentation adjustment device for a six-roller cold rolling mill according to claim 3, characterized in that: Upper intermediate roller bending cylinders for pushing the intermediate roller seats upward are provided below the intermediate roller seats at both ends of the upper intermediate roller, and lower intermediate roller bending cylinders for pushing the intermediate roller seats downward are provided above the intermediate roller seats at both ends of the lower intermediate roller.

7. The anti-indentation adjustment device for a six-roller cold rolling mill according to claim 3, characterized in that: Support roller balancing cylinders for pushing the support roller seats upwards are provided below the support roller seats at both ends of the upper support roller.

8. The anti-indentation adjustment device for a six-roller cold rolling mill according to claim 3, characterized in that: A rolling line adjustment mechanism is provided above the upper support roller.

9. The anti-indentation adjustment device for a six-roller cold rolling mill according to claim 8, characterized in that: The rolling line adjustment mechanism includes a pair of adjusting wedges located above the support roller seats at both ends of the upper support roller, the inclined surfaces of the adjusting wedges are facing downward, the bottom surfaces are flat and abut against the upper side surfaces of the support roller seats, and fixed wedges are fixedly connected to the tops of both sides of the frame, with the inclined surfaces of the fixed wedges facing downward and matching the inclined surfaces of the adjusting wedges.

10. The anti-indentation adjustment device for a six-roller cold rolling mill according to claim 9, characterized in that: A horizontal worm gear screw lift is installed on the middle top of the frame, the screw end of the worm gear screw lift is connected to the adjusting wedge on one side, the input end of the worm gear screw lift is coaxially connected to the main shaft of a hydraulic motor, and the adjusting wedges on both sides are connected together by a connecting beam.

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