Control method for eliminating small white spots of aluminum strip

Abstract

The invention provides a control method for eliminating small white points of an aluminum strip, which is used for eliminating the friction defect caused by interlayer air gap dislocation of an aluminum coiled material, and comprises the following steps of: in the process of coiling the strip into the coiled material with small tension, coiling the small white points on the surface of the strip close to a coiling point; the compactness between layers of the formed coiled material is increased by applying pressure acting on the upper surface of the strip so as to eliminate interlayer dislocation, and the pressure is matched with the width of the strip so that the tension of the strip can be prevented from being increased; according to the method, a constant pressure control device and a control system are additionally arranged in the strip coiling process, and by applying force vertically acting on the upper surface of the strip, gaps between layers in the strip coiling process can be reduced, interlayer dislocation can be eliminated, and the strip coiling quality can be improved under the condition that the tension of the strip is not increased. And the problem of small white spots in the production process of the aluminum coiled material is well solved.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum production, and in particular to a control method for eliminating small white spots on aluminum strips. Background Art

[0002] The production of aluminum coils in the slitting equipment belongs to the finished product process. Excessive tension during the coiling process will directly cause adhesion defects between the layers of the coil. For some alloy products, the tension is relatively small, at 5-7 N / mm². The relatively small tension makes it easy for the strip to be coiled loosely during the coiling process, with a certain air gap. During the transportation and production process, there will be slight misalignment between the layers of the strip, and small white spot friction defects will appear after unwinding, and serious cases will cause scratches, resulting in surface quality problems. Summary of the Invention

[0003] The present invention provides a control method for eliminating small white spots on aluminum strips. In this method, a constant pressure control device and a control system are added during the strip coiling process. By applying a force vertically on the upper surface of the strip, the gap between the layers during the strip coiling process can be reduced without increasing the strip tension, eliminating the misalignment between the layers, and preferably solving the problem of small white spots in the production process of aluminum coils.

[0004] The present invention adopts the following technical solutions.

[0005] A control method for eliminating small white spots on aluminum strips, which is used to eliminate the friction defects caused by the misalignment of the interlayer air gap of aluminum coils. During the process of coiling the strip into a coil with a small tension, on the surface of the strip near the coiling point, the compactness between the layers of the formed coil is increased by applying a pressure on the upper surface of the strip, so as to eliminate the misalignment between the layers. The magnitude of this pressure is matched with the width of the strip to avoid increasing the strip tension.

[0006] The surface of the strip near the coiling point for applying the force is the strip area at the tangent point of the coil, or the strip area slightly behind the tangent point. By applying a vertical pressure in this area, the air between the lower surface of the strip and the surface of the coil at the coiling point is extruded to eliminate the interlayer gap during the coil forming process.

[0007] The control method uses a control system and a constant pressure control device connected to the control system; the constant pressure control device includes a pressure roller for applying force to the strip. When the strip needs to be forced, the pressure roller descends until its roller surface acts vertically on the upper surface of the strip, as Figure 1 shown.

[0008] The pressure roller is a passive roller. When it contacts the upper surface of the strip, the pressure roller rotates synchronously with the movement of the strip during the coiling process.

[0009] The constant pressure control device includes a lifting device for driving the lifting of the pressure roller. The lifting device includes a constant pressure control device and a pressure detection device. The constant pressure control device calculates the pressure value P to be output to the pressure roller according to the width of the strip with different incoming widths. 给定 。

[0010] The constant pressure control device includes a calculation module and a hydraulic valve group with a proportional regulating valve. The hydraulic valve group is connected to the hydraulic cylinder of the lifting mechanism, and the lifting mechanism is connected to the passive roller to drive its lifting. P 给定 is the constant target pressure value of the system that the proportional regulating valve needs to adjust. The calculation module converts the calculated pressure value into a current signal in the range of 4 - 20 mA to drive the proportional valve.

[0011] The pressure detection device is used to detect the real-time feedback pressure value P of the hydraulic pressure. 检测 The pressure detection device is connected to the proportional regulating valve. The hydraulic cylinder is a hydraulic cylinder of the rod chamber type. During the coiling process of the coil, when the pressure roller is lifted as the coil diameter increases, the volume change of the rod chamber of the hydraulic cylinder will cause P 检测 to fluctuate. Then the pressure detection device makes the output constant target pressure value P of the hydraulic cylinder through the proportional regulating valve 给定 remain constant. The specific method is as follows: Compare the pressure value detected by the pressure sensor of the pressure detection device in real time. The formula is △P = P 给定 - P 检测 , The calculation module obtains △I through the operation of the pressure difference signal and calculates I 给定 = I 给定 + △I, and controls the proportional regulating valve with the current calculation structure to execute the closed-loop function of pressure control, so as to ensure that the pressure of the pressure roller remains constant during the process of the coil diameter increasing and the pressure roller rising.

[0012] The constant pressure control device calculates the pressure value that the hydraulic cylinder needs to press down according to the incoming material with different widths, conducts real-time feedback through the pressure detection device, and adjusts the proportional reducing valve in the constant pressure control device to adjust the constant pressure value output by the pressure roller to the coil.

[0013] When the strip is DC3003, the constant pressure control device sets the unit pressure on the strip surface to 250 - 300 kg / m. The pressure per unit width of the strip is set to f 带材 , then: F 作用力 = f 带材 * W 宽度 ; The constant pressure control device uses a hydraulic system to control the output pressure of the pressure roller. The specific process of pressure calculation is as follows: Assume the inner diameter of the hydraulic cylinder \(D = 0.15\ m\), the diameter of the piston rod \(d = 0.08\ m\), and the weight of the moving parts of the structure is \(150\ kg\). Calculated according to the unit pressure of the DC3003 product with a width of \(1\ m\) set at \(300\ kg / m\), the pressure calculation process is as follows: Effective area of the rodless cavity: \(S\) 无杆腔 =\(\pi\times(0.075)\) 2 =\(0.0177\ m^2\) 2 Effective area of the rod cavity: \(S\) 有杆腔 =\(\pi\times(0.04)\) 2 =\(0.005\ m^2\) 2 Calculate the pressure value \(P\) required by the system by substituting the above values 给定 It is: \(F\) 作用力 =\(F\) 无杆腔 -\(F\) 有杆腔 +\(m\) 结构 \(g\) (\(F\) 无杆腔 -\(F\) 有杆腔 )=\(F\) 作用力 -\(m\) 结构 \(g\) \(P\times\Delta S = F\) 作用力 -\(m\) 结构 \(g\) \(P\) 给定 =(\(F\) 作用力 -\(m\) 结构 \(g\)) / \(\Delta S\) \(P\) 给定 =(\(F\) 作用力 -\(m\) 结构 \(g\)) / (\(S\) 无杆腔 -\(S\) 有杆腔 ) \(P\) 给定 =(300*1*10 - 150*10) / (0.0177 - 0.005) =1500 / 0.0127 = 118110 (Pa) \(P\) 给定 is the system pressure value that the proportional valve needs to adjust. Convert the calculated pressure value into a 4 - 20 mA current signal to drive the proportional valve. (4 mA corresponds to a pressure value of 0, and 20 mA corresponds to the maximum pressure output value of 2 MPa). Then the initial current given to the valve is: \(I\) 给定 =\(kX + X_0\) (\(k\) is the proportional coefficient, and the substituted value is) =(20 - 4) / (2 - 0)*0.11811 + 4 = 4.945 mA.

[0014] The pressure roller is a polyurethane rubber roller with a diameter of 200 mm; the alloy model used for the aluminum coil has a tension range of 5 - 7 N / mm² during the production and coiling process.

[0015] The present invention can reduce the gap between layers during the coiling process of the strip without increasing the strip tension, eliminate the interlayer misalignment, and preferably solve the problem of small white spots during the production process of aluminum coils, while not affecting the production process of the aluminum coil coiling operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments: Attached Figure 1 is a schematic diagram of the principle of the present invention; Attached Figure 2 is a three-dimensional schematic diagram of the equipment used in the present invention; Attached Figure 3 is a schematic diagram of the principle of the constant pressure control device; Attached Figure 4 is a schematic diagram of the method principle for pressure adjustment of the present invention. SPECIFIC EMBODIMENTS

[0017] As shown in the figure, a control method for eliminating small white spots on an aluminum strip is used to eliminate the friction defects caused by the interlayer air gap misalignment of an aluminum coil. During the process of coiling the strip into a coil with a small tension, on the surface of the strip near the coiling point, the density of the formed coil layers is increased by applying a pressure acting on the upper surface of the strip to eliminate the interlayer misalignment, and the magnitude of this pressure is matched with the strip width to avoid increasing the strip tension.

[0018] The surface of the strip near the coiling point for applying the force is the strip area at the tangent point of the coil, or the strip area slightly behind the tangent point. By applying a vertical pressure in this area, the air between the lower surface of the strip and the surface of the coil at the coiling point is extruded to eliminate the interlayer gap during the coil forming process.

[0019] The control method uses a control system and a constant pressure control device connected to the control system; the constant pressure control device includes a pressure roller for applying force to the strip. When force needs to be applied to the strip, the pressure roller descends until its roller surface acts vertically on the upper surface of the strip, as Figure 1 shown.

[0020] The pressure roller is a passive roller. When it contacts the upper surface of the strip, the pressure roller rotates synchronously with the movement of the strip during the coiling process.

[0021] The constant pressure control device includes a lifting device for driving the lifting of the pressure roller. The lifting device includes a constant pressure control device and a pressure detection device. The constant pressure control device calculates the pressure value P to be output to the pressure roller according to the width of the strip with different incoming widths. 给定 。

[0022] The constant pressure control device includes a calculation module and a hydraulic valve group with a proportional regulating valve. The hydraulic valve group is connected to the hydraulic cylinder of the lifting mechanism, and the lifting mechanism is connected to the passive roller to drive its lifting. P 给定 is the system constant target pressure value that the proportional regulating valve needs to adjust. The calculation module converts the calculated pressure value into a current signal in the range of 4 - 20 mA to drive the proportional valve.

[0023] The pressure detection device is used to detect the real-time feedback pressure value P of the hydraulic pressure. 检测 The pressure detection device is connected to the proportional regulating valve. The hydraulic cylinder is a hydraulic cylinder of the rod chamber type. During the coiling process of the coil, when the pressure roller is lifted as the coil diameter increases, the volume change of the rod chamber of the hydraulic cylinder will cause P 检测 to fluctuate. Then the pressure detection device makes the output constant target pressure value P of the hydraulic cylinder constant through the proportional regulating valve. 给定 The specific method is as follows: Compare the pressure value detected by the pressure sensor of the pressure detection device in real time. The formula is △P = P 给定 - P 检测 , The calculation module obtains △I through the operation of the pressure difference signal, and calculates I 给定 = I 给定 + △I, and controls the proportional regulating valve with the current calculation structure to execute the closed-loop function of pressure control, so as to ensure that the pressure of the pressure roller is constant during the process of the coil diameter increasing and the pressure roller rising.

[0024] The constant pressure control device calculates the pressure value that the hydraulic cylinder needs to press down according to the incoming material with different widths, performs real-time feedback through the pressure detection device, and adjusts the proportional reducing valve in the constant pressure control device to adjust the constant pressure value output by the pressure roller to the coil.

[0025] When the strip is DC3003, the constant pressure control device sets the unit pressure on the surface of the strip to 250 - 300 kg / m. The pressure per unit width of the strip is set to f 带材 , then: F 作用力 = f 带材 * W 宽度 ; The constant pressure control device uses a hydraulic system to control the output pressure of the pressure roller. The specific process of pressure calculation is as follows: Suppose the inner diameter of the hydraulic cylinder D = 0.15 m, the diameter of the piston rod d = 0.08 m, and the weight of the moving parts of the structure is 150 kg. Calculated according to the unit pressure of 300 kg / m for the DC3003 product with a width of 1 m, the pressure calculation process is as follows: Effective area of the rodless cavity: S 无杆腔 = π×(0.075) 2 = 0.0177 m 2 Effective area of the rod cavity: S 有杆腔 = π×(0.04) 2 = 0.005 m 2 Calculate the pressure value P required by the system by substituting the above values 给定 It is: F 作用力 = F 无杆腔 - F 有杆腔 + m 结构 g (F 无杆腔 - F 有杆腔 )= F 作用力 - m 结构 g P*△S = F 作用力 - m 结构 g P 给定 =(F 作用力 - m 结构 g) / △S P 给定 =(F 作用力 - m 结构 g) / (S 无杆腔 - S 有杆腔 ) P 给定 =(300*1*10 - 150*10) / (0.0177 - 0.005) = 1500 / 0.0127 = 118110(Pa) P 给定 is the system pressure value that the proportional valve needs to adjust. Convert the calculated pressure value to a 4 - 20 mA current signal to drive the proportional valve. (4 mA corresponds to a pressure value of 0, and 20 mA corresponds to the maximum pressure output value of 2 MPa). Then the initial current given to the valve is: I 给定 = kX + X0 (k is the proportional coefficient, and the substituted value is) =(20 - 4) / (2 - 0)*0.11811 + 4 = 4.945 mA。

[0026] The pressure roller is a polyurethane rubber roller with a diameter of 200 mm; the alloy model of the aluminum coil has a tension range of 5 - 7 N / mm² during the production coiling process.

[0027] Embodiment In this example, during the coil coiling process, a set of constant pressure control device is added. When not in use, the roller surface is lifted, and when in use, the roller surface acts vertically on the upper surface of the strip. There will be a certain amount of gap on the lower surface of the strip during coiling due to the relatively small tension. This device has a better effect at the coil tangent point and slightly behind the tangent point, and is used to squeeze out the air on the lower surface of the strip and eliminate the gap; as Figure 1 shown In the constant pressure control device of this example, a set of vertically liftable mechanism is installed. In the middle is a hydraulic device that drives the lifting of the roller. This roller is a passive roller and rotates with the strip when contacting the upper surface of the strip. This roller is a polyurethane rubber roller with a diameter of 200 mm, as Figure 2 .

[0028] To achieve constant pressure control, a set of hydraulic valve group with a proportional regulating valve is installed in this example, which is connected to the hydraulic cylinder of the lifting mechanism; as Figure 3 shown, This example includes a set of pressure detection devices for detecting the real-time feedback pressure value of the hydraulic pressure; according to the incoming material of different widths, calculate the pressure value that the hydraulic cylinder needs to press down, perform real-time feedback through the pressure detection device, and adjust the proportional pressure reducing valve to achieve the control of the constant pressure of the pressure roller on the coil.

[0029] The product specifications targeted in this example are as follows in the table Remarks: The pressure per unit width of the strip is set to f 带材 , then: F 作用力 = f 带材 * W 宽度 When calculating the pressure, this equipment device uses a hydraulic system for control. The inner diameter D of the hydraulic cylinder is 0.15 m, the piston rod diameter d is 0.08 m, and the weight of the structural moving parts is about 150 kg. Calculated according to the unit pressure of 300 kg / m for the DC3003 product with a width of 1 m, the pressure calculation process is as follows: The effective area of the rodless cavity: S 无杆腔 = π×(0.075) 2 = 0.0177 m 2 The effective area of the rod cavity: S 有杆腔 = π×(0.04) 2 = 0.005 m 2 Calculate the pressure value P required by the system by substituting the above values给定 is: F 作用力 = F 无杆腔 - F 有杆腔 + m 结构 g (F 无杆腔 - F 有杆腔 ) = F 作用力 - m 结构 g P * △S = F 作用力 - m 结构 g P 给定 = (F 作用力 - m 结构 g) / △S P 给定 = (F 作用力 - m 结构 g) / (S 无杆腔 - S 有杆腔 ) P 给定 = (300 * 1 * 10 - 150 * 10) / (0.0177 - 0.005) = 1500 / 0.0127 = 118110 (Pa) P 给定 is the system pressure value that the proportional valve needs to adjust. Convert the calculated pressure value into a 4 - 20 mA current signal to drive the proportional valve. (4 mA corresponds to 0 pressure value, and 20 mA corresponds to the maximum pressure output value of 2 MPa). Then the initial current given to the valve is: I 给定 = kX + X0 (k is the proportional coefficient, which is a substituted value) = (20 - 4) / (2 - 0) * 0.11811 + 4 = 4.945 mA The method of pressure regulation is as follows: As the strip coil diameter increases, the pressure roller will be gradually lifted. During the rising process of the oil cylinder, the volume of the rod chamber changes, and the P 检测 pressure value fluctuates. To ensure a constant target pressure value P 给定 , compare the pressure value detected by the pressure sensor in real - time △P = P 给定 - P 检测 . Calculate the △I from the pressure difference signal and realize the dynamic adjustment of the current I 给定 = I 给定 + △I to achieve the closed - loop function and ensure a constant pressure during the rising process.

Claims

1. A control method for eliminating small white dots on aluminum strip materials, which is used to eliminate the friction defects caused by the dislocation of the interlayer air gap in aluminum coils, and is characterized in that: During the process of coiling the strip into a coil with a small tension, on the surface of the strip near the coiling point, the density between the formed coil layers is increased by applying a pressure acting on the upper surface of the strip to eliminate the dislocation between the layers. The magnitude of this pressure is matched with the width of the strip to avoid increasing the strip tension.

2. The control method for eliminating small white dots on aluminum strip according to claim 1, characterized in that: The surface of the strip near the coiling point for applying force is the strip area at the tangent point of the coil or the strip area slightly behind the tangent point. By applying a vertical pressure in this area, the air between the lower surface of the strip and the surface of the coil at the coiling point is squeezed out to eliminate the interlayer gap during the coil forming process.

3. The control method for eliminating small white dots on aluminum strip according to claim 2, characterized in that: The control method uses a control system and a constant pressure control device connected to the control system; the constant pressure control device includes a pressure roller for applying force to the strip. When force needs to be applied to the strip, the pressure roller descends until its roller surface acts vertically on the upper surface of the strip.

4. A control method for eliminating small white dots on an aluminum strip according to claim 3, characterized in that: The pressure roller is a passive roller. When it contacts the upper surface of the strip, the pressure roller rotates synchronously with the movement of the strip during coiling.

5. A control method for eliminating small white dots on an aluminum strip according to claim 4, characterized in that: The constant pressure control device includes a lifting device for driving the lifting of the pressure roller. The lifting device includes a constant pressure control device and a pressure detection device. The constant pressure control device calculates the pressure value P to be output to the pressure roller according to the width of the strip with different incoming widths 给定 .

6. The control method for eliminating small white dots on aluminum strip according to claim 5, characterized in that: The constant pressure control device includes a calculation module and a hydraulic valve group with a proportional regulating valve. The hydraulic valve group is connected to the hydraulic cylinder of the lifting mechanism, and the lifting mechanism is connected to the passive roller to drive its lifting. P 给定 It is the constant target pressure value of the system that the proportional regulating valve needs to regulate; the calculation module converts the calculated pressure value into a current signal in the range of 4 - 20 mA to drive the proportional valve.

7. A control method for eliminating small white dots on aluminum strip according to claim 6, characterized in that: The pressure detection device is used to detect the real-time feedback pressure value P of the hydraulic pressure 检测 ; The pressure detection device is connected to the proportional control valve; The hydraulic cylinder is a hydraulic cylinder of the rod chamber type. During the process of coiling the coil, when the pressure roller is lifted as the coil diameter increases, the volume change of the rod chamber of the hydraulic cylinder will cause P 检测 to fluctuate. Then, the pressure detection device makes the output of the hydraulic cylinder maintain a constant target pressure value P 给定 constant through a proportional regulating valve. The specific method is as follows: Compare the pressure values detected in real time by the pressure sensor of the pressure detection device. The formula is △P = P 给定 - P 检测 , The calculation module calculates △I through the pressure difference signal operation, and calculates I by dynamically adjusting the current. 给定 =I 给定 +△I, controls the proportional regulating valve with the current calculation structure to execute the closed-loop function of pressure control, so as to ensure that the pressure of the pressure roller is constant during the process of the pressure roller rising when the coil diameter increases.

8. A control method for eliminating small white spots on aluminum strip according to claim 5, characterized in that: The constant pressure control device calculates the pressure value that the hydraulic cylinder needs to press down according to the incoming material of different widths, performs real-time feedback through a pressure detection device, and adjusts the proportional pressure reducing valve in the constant pressure control device to adjust the constant pressure value output by the pressure roller to the coil.

9. The control method for eliminating small white dots on aluminum strip according to claim 8, characterized in that: When the strip is DC3003, the unit pressure on the surface of the strip by the constant pressure control device is set to 250 - 300 kg / m. The pressure per unit width of the strip is set to f 带材 , then: F 作用力 = f 带材 * W 宽度 ; The constant pressure control device uses a hydraulic system to control the output pressure of the pressure roller. The specific process of pressure calculation is as follows: Suppose the inner diameter D of the hydraulic cylinder is 0.15 m, the piston rod diameter d is 0.08 m, and the weight of the structural moving part is 150 kg. Calculated according to the unit pressure of 300 kg / m for a 1m-wide DC3003 product, the pressure calculation process is as follows: Effective area of the rodless cavity: S 无杆腔 = π × (0.075) 2 = 0.0177 m 2 Effective area of the rod chamber: S 有杆腔 =π×(0.04) 2 =0.005 m 2 Calculate the required pressure value P of the system by substituting the above values 给定 It is: F 作用力 = F 无杆腔 −F 有杆腔 + m 结构 g (F 无杆腔 - F 有杆腔 ) = F 作用力 - m 结构 g P*△S = F 作用力 -m 结构 g P 给定 = (F 作用力 - m 结构 g) / △S P 给定 = (F 作用力 - m 结构 g) / (S 无杆腔 - S 有杆腔 ) P 给定 =（300*1*10-150*10） / （0.0177 - 0.005） = 1500 / 0.0127 = 118110 (Pa) P 给定 is the system pressure value that the proportional valve needs to adjust; The calculated pressure value is converted into a 4 - 20 mA current signal to drive the proportional valve. 4 mA corresponds to a pressure value of 0, 20 mA corresponds to the maximum pressure output value of 2 MPa, and k is the proportional coefficient. Then the initial current given to the valve is: I 给定 = kX + X0 = (20 - 4) / (2 - 0) * 0.11811 + 4 = 4.945 mA.

10. The control method for eliminating small white dots on aluminum strip according to claim 3, characterized in that: The pressure roller is a polyurethane rubber roller; the alloy model of the aluminum coil has a tension range of 5 - 7 N / mm² during the production coiling process.

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