A rolling method capable of realizing axial variable tension

Abstract

The present invention belongs to the technical field of plate and strip rolling, and particularly relates to a rolling method that can achieve axial variable tension. The rolling method is implemented by a tension roller device for axial variable tension rolling, and the specific steps are: calculating the pressure required to be provided in each segment of the expandable bladder; providing pressure medium to the segmented expandable bladder outside the tension roller core through a control valve group and a rotary joint, so that the pressure in each segment of the expandable bladder reaches the calculated required pressure; directly contacting each segment of the expandable bladder with the plate and strip to be processed, constructing different tensile stresses in the width direction of the plate and strip, and performing variable tension rolling. The present invention provides pressure medium to the segmented expandable bladder outside the tension roller core through a control valve group, realizes different pressure control in the segmented expandable bladder, and realizes applying different supporting forces along the axial direction of the tension roller, thereby realizing variable tension rolling in the width direction of the plate and strip during the rolling process, improving the control ability and flexibility of tension on the plate shape, and is conducive to improving the quality of the plate and strip.

Description

Technical Field

[0001] The invention belongs to the technical field of plate and strip rolling, and in particular relates to a rolling method capable of realizing axial variable tension. Background Art

[0002] Tension is an important process parameter that affects the distribution of rolling force and an important variable for controlling the flatness of the strip. Tension feedback is an important mechanism to ensure good plate shape during the rolling process. When the longitudinal extension of a certain position in the width direction of the strip is large, the corresponding longitudinal tensile stress will decrease, which will in turn increase the rolling pressure per unit width at the corresponding position, thereby increasing the elastic flattening of the roller, which in turn inhibits the longitudinal extension of the strip at this position. Finally, the difference in the transverse distribution of tension coordinates the longitudinal deformation of the plate and strip to a certain extent, avoiding the deterioration of the plate shape to buckling instability. For traditional cold rolling, the mill structure is fixed, the control domain of conventional plate shape control means is fixed, and the rolling tension rollers are located on both sides of the mill entrance and exit. Tension is one of the most direct and effective control means for plate shape control. Giving full play to the ability of tension to control plate shape is an important direction for further exploring the efficiency of rolling plate shape control.

[0003] Different types of rolling mill shape control methods have different control capabilities and control effects on the transverse flatness of the strip, but most of them are to control the shape by adjusting the bending roll force of different rolls, the lateral shift of the intermediate roll, the tilting roll, the segmented cooling, and the high-tension rolling. However, the bending roll force and the lateral shift of the roll have a main effect on the edge, the tilting roll mainly controls the wedge shape of the strip, and the segmented cooling mainly controls the high-order wave shape. It is a near-steady-state control process with poor real-time performance. High tension is conducive to reducing the rolling force, and the fine control ability of the local strip shape is poor. Therefore, the scope of each shape control method in the width direction of the strip is limited, and under the limited constraints of the rolling and subsequent heat treatment control process, the shape control target is certain. For strips with high requirements for cross-sectional profile control, such as silicon steel and DI materials, the cross-sectional profile control of the strip has developed from the traditional center section convexity control to the edge thinning control. The coupling phenomenon of flatness and cross-sectional profile control is very likely to occur in the production process, especially the development of conventional cold rolling to ultra-thin rolling. The demand for new shape control methods has become more and more urgent. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a rolling method that can achieve axial variable tension. By controlling the pressure in each section of the expandable bladder through a control valve group, different supporting forces are applied along the axial direction of the tension roller, and then different tensile stresses are constructed in the width direction of the plate and strip. The present invention can be used as a winding guide roller, a tension roller group, a tension measuring roller, and an inter-frame loop roller. While meeting the process requirements, different supporting reaction forces are constructed for the plate and strip, thereby achieving variable tension rolling in the width direction of the plate and strip during the rolling process, improving the control ability and flexibility of the tension on the plate shape, providing a more powerful plate shape control means for the efficient rolling of precision strips, and is beneficial to improving the quality of plate and strip materials.

[0005] The technical solution of the present invention is: a rolling method capable of realizing axial variable tension, the rolling method is realized by a tension roller device for axial variable tension rolling, the tension roller device for axial variable tension rolling comprises a tension roller core shaft, an expandable bag is arranged on the outer side of the tension roller core shaft, the expandable bag is arranged in sections along the axial direction of the tension roller core shaft, a rotary joint is arranged at each end of the tension roller core shaft, a plurality of connecting holes are arranged on the rotary joint, a plurality of channels are arranged inside the tension roller core shaft, one end of the channel is connected to the inside of the segmented expandable bag, and the other end is connected to the connecting hole of the rotary joint, a control valve group is connected to the rotary joint, the control valve group is connected to a pressure source, the pressure source provides pressure medium to the segmented expandable bag outside the tension roller core shaft through the control valve group and the rotary joint, so as to realize different pressure control in the segmented expandable bag, the rolling method comprises the following steps:

[0006] S1: each section of the expandable bladder is directly contacted with the plate strip to be processed, so that the plate strip forms a wrap angle of 30° to 150° around the tension roller device;

[0007] S2: Use a shape meter to measure the actual shape of the strip at the mill exit and obtain the measured longitudinal residual stress , according to the target residual stress of the plate Calculate the longitudinal residual stress that needs to be compensated by the axial variable tension roller, that is, the tensile stress that needs to be compensated locally in the strip ;

[0008] S3: Based on the tensile stress that needs to be compensated locally in the plate strip in S2 , calculate the pressure required to be provided in each section of the expandable bladder ;

[0009] S4: Provide pressure medium to the segmented expandable bladder outside the tension roller core shaft through the control valve group and the rotary joint, so that the pressure inside each segment of the expandable bladder reaches the required pressure calculated in S3. ;

[0010] S5: By changing the supporting force of each section of the expandable bladder on the surface of the plate and strip, different tensile stresses are constructed in the width direction of the plate and strip, and variable tension rolling operations are performed.

[0011] The tensile stress of the strip that needs to be compensated locally in step S2 Target residual stress of plate and strip And measured longitudinal residual stress Satisfies the following relationship:

[0012] (1)

[0013] Since the expandable bladder cannot provide compressive stress for the strip, it does not compensate for the compressive stress required by the strip. The corrected strip needs to compensate for the tensile stress locally. for

[0014] (2)

[0015] Use close The positive pressure value at the position is linearly interpolated or quadratically interpolated according to the slope change law to obtain the tensile stress that needs to be compensated in the local area of ​​the plate after interpolation. , and then obtain the corrected tensile stress that needs to be compensated locally on the strip for

[0016] (3)

[0017] The pressure required to be provided in each section of the expandable bladder in step S3 The tensile stress that needs to be compensated locally on the strip satisfy

[0018] (4)

[0019] In the formula, h is the strip thickness, mm; It is half of the wrap angle of the strip around the tension roller. is the local width of the strip, mm, is the nominal radius of the tension roller, mm; is the tensile stress that needs to be compensated locally in the plate strip, MPa, The internal pressure of the capsule, MPa, is the integration variable;

[0020] Thus, the pressure required to be provided in each section of the expandable bladder is obtained. The tensile stress that needs to be compensated locally on the strip The relationship is:

[0021] (5)

[0022] Consider the distance attenuation effect and increase the compensation coefficient According to the negative value zeroing method, the pressure inside the hydraulic or pneumatic bag of each section of the tension roller equipment is obtained. The size is:

[0023] (6)

[0024] Or use the interpolation method to obtain the pressure in each section of the hydraulic or pneumatic bag of the tension roller The size is:

[0025] (7)

[0026] Each segment of the inflatable bladder is connected to two channels, one channel is the input channel of the pressure medium, and the other channel is the output channel of the pressure medium. The input channel of the pressure medium is connected to the rotary joint on the left side of the tension roller core shaft, and the output channel of the pressure medium is connected to the rotary joint on the right side of the tension roller core shaft.

[0027] The pressure source is a hydraulic oil source or an air pressure source.

[0028] The control valve group is a pressure reducing valve group and a back pressure valve group. The pressure reducing valve group is connected to the rotary joint on the left side of the tension roller core shaft. The pressure reducing valve group includes a P1 pressure reducing valve, a P2 pressure reducing valve, a P3 pressure reducing valve, and a P4 pressure reducing valve. n Pressure reducing valve, a total of n groups of pressure reducing valves, n is the number of segments of the inflatable bag, P n The pressure reducing valve is connected to the nth segment of the expandable bag, and the back pressure valve group is connected to the rotary joint on the right side of the tension roller core shaft. The back pressure valve group includes P 1 Back pressure valve, P 2 Back pressure valve, P 3 Back pressure valve…P n Back pressure valve, a total of n groups of back pressure valves, n is the number of segments of the expandable bag, P n The back pressure valve is in communication with the nth segment of the inflatable bladder.

[0029] The pressure reducing valve group is connected to the pressure source, and the back pressure valve group is connected to the hydraulic oil tank or the air silencer system.

[0030] The P n Pressure reducing valve with the P n Back pressure valve differential pressure connection.

[0031] The pressure reducing valve group is a pilot electromagnetic proportional pressure reducing valve group with feedback or an electro-hydraulic pressure servo valve, and the back pressure valve group is a pilot electromagnetic proportional sequence valve group with feedback or an electro-hydraulic pressure servo valve.

[0032] The technical effects of the present invention are: 1. The pressure source of the present invention provides pressure medium to the segmented expandable bag outside the tension roller core shaft through the control valve group and the rotary joint, so as to realize different pressure control in the segmented expandable bag, thereby realizing different supporting forces along the axial direction of the tension roller, realizing variable tension rolling in the width direction of the plate and strip during the rolling process, improving the control ability and flexibility of the tension on the plate shape, and being beneficial to improving the quality of the plate and strip material; 2. The tension roller of the present invention can be used as a winding guide roller, a tension roller group, a tension meter roller, a looper roller between frames, etc., which can meet the process requirements while ensuring the stability of the plate and strip structure. The same support reaction force provides a more powerful plate shape control means for the efficient rolling of precision strips; 3. The control valve group of the present invention can realize the variable pressure of the axial airbag through the pressure reducing valve group and the back pressure valve group, thereby realizing the application of different supporting forces to the plate and strip, realizing the segmented variable tensile stress structure in the width direction of the plate and strip, and achieving the purpose of segmented adjustment of the plate shape. The implementation method can be differential pressure type or pressure reducing constant pressure-back pressure type, and the adjustment method is fast, accurate, simple and flexible; 4. The present invention adopts a flexible expandable bag to avoid scratches on the surface of the plate and strip caused by rigid rollers, thereby improving the plate shape and surface quality of the plate and strip after rolling.

[0033] The following is a further description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of a pressure reducing and constant pressure-overflow hydraulic structure for a rolling device capable of achieving axial variable tension according to an embodiment of the present invention.

[0035] Figure 2 The present invention is a schematic diagram of the balance between the tension roller support pressure and the longitudinal stress of the plate and strip in a rolling method capable of achieving axial variable tension in an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of a differential pressure hydraulic structure of a rolling equipment capable of achieving axial variable tension according to an embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of a reduced pressure, constant pressure and back pressure hydraulic structure for a rolling device capable of achieving axial variable tension according to an embodiment of the present invention.

[0038] Figure 5 This is a schematic diagram of a differential pressure gas pressure structure of a rolling equipment capable of achieving axial variable tension according to an embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram of a reduced pressure, constant pressure and back pressure gas pressure structure for a rolling device capable of achieving axial variable tension according to an embodiment of the present invention.

[0040] Figure 7 The present invention is a schematic diagram of a tension roller core shaft structure of a rolling equipment capable of achieving axial variable tension.

[0041] Figure 8 This is a cross-sectional view of the tension roller core shaft AA of a rolling equipment capable of achieving axial variable tension according to an embodiment of the present invention.

[0042] Fig. 9 This is a cross-sectional view of a tension roller core shaft BB of a rolling device capable of achieving axial variable tension according to an embodiment of the present invention.

[0043] Fig.10 This is a schematic diagram of the three-dimensional structure of a tension roller core shaft of a rolling equipment capable of achieving axial variable tension according to an embodiment of the present invention.

[0044] Fig.11 This is a schematic diagram of the three-dimensional structure of a swivel joint of a rolling equipment capable of achieving axial variable tension according to an embodiment of the present invention.

[0045] Fig.12 This is a schematic diagram of the three-dimensional structure of a rolling equipment capable of achieving axial variable tension according to an embodiment of the present invention.

[0046] Fig.13 Schematic diagram of residual stress distribution of target plate shape of a plate strip according to an embodiment of the present invention.

[0047] Fig.14 It is a schematic diagram of residual stress distribution of the plate shape actually measured in the plate strip according to the embodiment of the present invention.

[0048] Fig.15 Schematic diagram of compensation for residual stress distribution of a plate strip according to a negative value zeroing method in an embodiment of the present invention.

[0049] Fig.16 Schematic diagram of the interpolation method for compensating residual stress distribution of a plate strip according to an embodiment of the present invention.

[0050] Fig.17 Schematic diagram of the axial stress distribution of the tension roller liquid / air pressure bag in an embodiment of the present invention.

[0051] Fig.18 This is a schematic diagram of the Mises equivalent stress distribution of the plate and strip with different radial force distributions of the tension roller along the axial direction when the tension roller wrap angle is 150° in an embodiment of the present invention.

[0052] Fig.19 This is a schematic diagram of the longitudinal stress of the strip 200 mm away from the head of the strip after the longitudinal stress distribution of the strip after the axial support force is varied when the wrap angle of the tension roller is 150° in an embodiment of the present invention.

[0053] Fig. 20 This is a schematic diagram of the longitudinal stress of the strip 1000 mm away from the head of the strip after the longitudinal stress distribution of the strip after the axial support force is varied when the wrap angle of the tension roller is 150° in an embodiment of the present invention.

[0054] Fig.21It is a cloud diagram of the longitudinal stress distribution of the plate strip and the Mises equivalent stress borne by the corresponding tension roller surface when the tension roller wrap angle is 150° in an embodiment of the present invention.

[0055] Fig. 22 Schematic diagram of the distribution of tension roller support reaction force caused by the longitudinal stress of the strip when the tension roller wrap angle is 150° in an embodiment of the present invention.

[0056] Fig.23 This is a Mises stress cloud diagram under the coupling effect of different radial support forces of the tension roller and the longitudinal stress of the plate and strip when the wrap angle of the tension roller is 120° in an embodiment of the present invention.

[0057] Fig.24 Schematic diagram of the distribution of Mises equivalent stress on the roller surface along the roller axis when the wrap angle of the tension roller is 120° in an embodiment of the present invention.

[0058] Fig.25 This is a longitudinal stress diagram of the strip 200 mm away from the head of the strip when the wrap angle of the tension roller is 120° in an embodiment of the present invention and the stress distribution of the coupling effect of the variable axial support force and the strip tension.

[0059] Fig.26 This is a longitudinal stress diagram of the strip 1000 mm away from the head of the strip when the wrap angle of the tension roller is 120° in an embodiment of the present invention and the stress distribution of the coupling effect of the variable axial support force and the strip tension.

[0060] Fig. 27 This is a Mises stress cloud diagram under the coupling effect of different radial support forces of the tension roller and the longitudinal stress of the plate and strip when the wrap angle of the tension roller is 135° in an embodiment of the present invention.

[0061] Fig.28 This is the Mises equivalent stress distribution diagram along the roller axial direction and the roller surface of the embodiment of the present invention, showing the stress distribution of the coupling effect of the variable axial support force and the strip tension when the tension roller wrap angle is 135°.

[0062] Fig.29 This is a longitudinal stress diagram of the strip 200 mm away from the head of the strip when the wrap angle of the tension roller is 135° in an embodiment of the present invention and the stress distribution of the coupling effect of the variable axial support force and the strip tension.

[0063] Fig.30 This is a longitudinal stress diagram of the strip 1000mm away from the head of the strip when the wrap angle of the tension roller is 135° in an embodiment of the present invention and the stress distribution of the coupling effect of the variable axial support force and the strip tension.

[0064] Fig.31 This is the Mises stress cloud diagram of the stress distribution of the coupling effect of the varying axial support force and the strip tension when the wrap angle of the tension roller is 150° in an embodiment of the present invention, and the coupling effect of different radial support forces of the tension roller and the longitudinal stress of the strip.

[0065] Fig.32 This is the Mises equivalent stress distribution along the roller axial direction and the roller surface of the roller when the tension roller wrap angle is 150° in an embodiment of the present invention.

[0066] Fig.33 This is a longitudinal stress diagram of the strip 200 mm away from the head of the strip when the wrap angle of the tension roller is 150° and the stress distributions of the coupling effect of the variable axial support force and the strip tension in an embodiment of the present invention.

[0067] Fig.34 This is a longitudinal stress diagram of the strip 1000 mm away from the head of the strip when the wrap angle of the tension roller is 150° in an embodiment of the present invention and the stress distribution of the coupling effect of the variable axial support force and the strip tension.

[0068] Figure numerals: 1-inflatable bladder; 2-tension roller core shaft; 3-swivel joint; 4-pressure reducing valve group; 5-back pressure valve group; 6-hydraulic oil source; 7-air pressure source; 8-output channel of pressure medium; 9-input channel of pressure medium. DETAILED DESCRIPTION

[0069] Example 1

[0070] like Figure 1 , Figures 10-12 As shown, a rolling method capable of realizing axial variable tension is realized by a tension roller device for axial variable tension rolling, the tension roller device for axial variable tension rolling comprises a tension roller core shaft 2, an expandable capsule 1 is arranged on the outer side of the tension roller core shaft 2, the expandable capsule 1 is arranged in sections along the axial direction of the tension roller core shaft 2, a rotary joint 3 is arranged at each end of the tension roller core shaft 2, a plurality of connecting holes are arranged on the rotary joint 3, a plurality of channels are arranged inside the tension roller core shaft 2, one end of the channel is connected to the inside of the segmented expandable capsule 1, and the other end is connected to the connecting hole of the rotary joint 3, a control valve group is connected to the rotary joint 3, the control valve group is connected to a pressure source, the pressure source provides pressure medium to the segmented expandable capsule 1 outside the tension roller core shaft 2 through the control valve group and the rotary joint 3, so as to realize different pressure control in the segmented expandable capsule 1, the rolling method comprises the following steps:

[0071] S1: each section of the expandable bladder 1 is directly contacted with the plate strip to be processed, so that the plate strip forms a wrap angle of 30° to 150° around the tension roller device;

[0072] S2: Use a shape meter to measure the actual shape of the strip at the mill exit and obtain the measured longitudinal residual stress , according to the target residual stress of the plate Calculate the longitudinal residual stress that needs to be compensated by the axial variable tension roller, that is, the tensile stress that needs to be compensated locally in the strip ;

[0073] S3: Based on the tensile stress that needs to be compensated locally in the plate strip in S2 , calculate the pressure required to be provided in each section of the expandable bladder 1 ;

[0074] S4: Provide pressure medium to the segmented expandable bladder 1 outside the tension roller core shaft 2 through the control valve group and the rotary joint 3, so that the pressure inside each segment of the expandable bladder 1 reaches the required pressure calculated in S3. ;

[0075] S5: By changing the supporting force of each section of the expandable bladder 1 on the surface of the plate and strip, different tensile stresses are constructed in the width direction of the plate and strip, and variable tension rolling operation is performed.

[0076] In actual use, the pressure source of the present invention provides pressure medium to the segmented expandable bag 1 outside the tension roller core shaft 2 through the control valve group and the rotary joint, so as to realize different pressure control in the segmented expandable bag 1, thereby realizing different supporting forces along the axial direction of the tension roller, realizing variable tension rolling in the width direction of the plate and strip during the rolling process, improving the control ability and flexibility of the tension on the plate shape, and being conducive to improving the quality of the plate and strip.

[0077] The tensile stress of the strip that needs to be compensated locally in step S2 Target residual stress of plate and strip And measured longitudinal residual stress Satisfies the following relationship:

[0078] (1)

[0079] Since the expandable bladder 1 cannot provide compressive stress for the strip, it does not compensate for the compressive stress required by the strip. The tensile stress required to be compensated locally in the strip after correction is for

[0080] (2)

[0081] Use close The positive pressure value at the position is linearly interpolated or quadratically interpolated according to the slope change law to obtain the tensile stress that needs to be compensated in the local area of ​​the plate after interpolation. , and then obtain the corrected tensile stress that needs to be compensated locally on the strip for

[0082] (3)

[0083] like Figure 2 As shown, the pressure required to be provided in each section of the expandable bladder (1) in step S3 is The tensile stress that needs to be compensated locally on the strip satisfy

[0084] (4)

[0085] In the formula, h is the strip thickness, mm; It is half of the wrap angle of the strip around the tension roller. is the local width of the strip, mm, is the nominal radius of the tension roller, mm; is the tensile stress that needs to be compensated locally in the plate strip, MPa, The internal pressure of the capsule, MPa; is the integration variable;

[0086] Thus, the pressure required to be provided in each section of the expandable bladder 1 is obtained. The tensile stress that needs to be compensated locally on the strip The relationship is:

[0087] (5)

[0088] Consider the distance attenuation effect and increase the compensation coefficient According to the negative value zeroing method, the pressure inside the hydraulic or pneumatic bag of each section of the tension roller equipment is obtained. The size is:

[0089] (6)

[0090] Or use the interpolation method to obtain the pressure in each section of the hydraulic or pneumatic bag of the tension roller The size is:

[0091] (7)

[0092] like Figure 7~Figure 9 As shown, each segment of the inflatable bladder 1 is connected to two channels inside, one channel is an input channel 9 for the pressure medium, and the other channel is an output channel 8 for the pressure medium. The input channel 9 for the pressure medium is connected to the rotary joint 3 on the left side of the tension roller core shaft 2, and the output channel 8 for the pressure medium is connected to the rotary joint 3 on the right side of the tension roller core shaft 2.

[0093] During actual use, each segment of the inflatable bladder 1 of the present invention is connected to two channels, one channel is an input channel 9 for the pressure medium, and the other channel is an output channel 8 for the pressure medium, so that the control valve group can control the pressure of the inflatable bladder 1.

[0094] Preferably, Figure 1 , Figure 3~Figure 6 As shown, the pressure source is a hydraulic oil source 6 or an air pressure source 7.

[0095] In actual use, the pressure source of the present invention is a hydraulic oil source 6 or an air pressure source 7, and pressure control is flexible and convenient.

[0096] Preferably, Figure 3~Figure 6 As shown, the control valve group is a pressure reducing valve group 4 and a back pressure valve group 5. The pressure reducing valve group 4 is connected to the rotary joint 3 on the left side of the tension roller core shaft 2. The pressure reducing valve group 4 includes a P1 pressure reducing valve, a P2 pressure reducing valve, a P3 pressure reducing valve, and a P4 pressure reducing valve. n Pressure reducing valves, a total of n groups of pressure reducing valves, n is the number of segments of the inflatable bag 1, P n The pressure reducing valve is connected to the nth segment of the expandable bag 1, and the back pressure valve group 5 is connected to the rotary joint 3 on the right side of the tension roller core shaft 2. The back pressure valve group 5 includes P 1 Back pressure valve, P 2 Back pressure valve, P 3 Back pressure valve…P n Back pressure valve, a total of n groups of back pressure valves, n is the number of segments of the expandable bag 1, P n The back pressure valve is connected to the nth segment of the inflatable bladder 1 .

[0097] In actual use, the present invention P n The pressure reducing valve is connected to the nth segment of the inflatable bladder 1, so as to provide pressure medium to the segmented inflatable bladder 1, realize different pressure control in the segmented inflatable bladder 1, and improve the control accuracy. n The back pressure valve is connected to the nth segment of the inflatable bladder 1 to provide pressure medium to the segmented inflatable bladder 1, thereby achieving different pressure controls in the segmented inflatable bladder 3 and improving control accuracy.

[0098] Preferably, the pressure reducing valve group 4 is connected to the pressure source, and the back pressure valve group 5 is connected to the hydraulic oil tank or the air silencer system.

[0099] During actual use, the pressure reducing valve group 4 of the present invention is connected to the pressure source, so that the pressure source provides pressure medium for the pressure reducing valve group 4. The back pressure valve group 5 of the present invention is connected to the hydraulic oil tank or the air silencer system, so as to control the rapid pressure relief.

[0100] Preferably, the P n Pressure reducing valve with the P n Back pressure valve differential pressure connection.

[0101] The P of the present invention n Pressure reducing valve with the P n The back pressure valve differential pressure connection realizes differential pressure reduction, facilitates the pressure adjustment of each section of the bladder, and improves the pressure control capability.

[0102] Preferably, the pressure reducing valve group is a pilot electromagnetic proportional pressure reducing valve group with feedback or an electro-hydraulic pressure servo valve, and the back pressure valve group is a pilot electromagnetic proportional sequence valve group with feedback or an electro-hydraulic pressure servo valve.

[0103] During actual use, the pressure reducing valve group described in the present invention is a pilot electromagnetic proportional pressure reducing valve group with feedback, and the back-pressure valve group is a pilot electromagnetic proportional sequential valve group with feedback. The control valve group can realize variable pressure of the axial airbag through the pressure reducing valve group and the back-pressure valve group, thereby realizing the application of different supporting forces to the plate strip, realizing the segmented variable tensile stress structure in the width direction of the plate strip, and achieving the purpose of segmented adjustment of the plate shape. The implementation method can be differential pressure type or pressure reducing constant pressure-back pressure type, and the adjustment method is fast, accurate, simple and flexible.

[0104] Preferably, the expandable bladder 1 is uniformly coated on the outer side of the tension roller core shaft 2, and the various sections of the expandable bladder 1 are flexibly connected into one body, and are in direct contact with the plate strip during operation.

[0105] In actual use, the present invention adopts a flexible expandable bag 1 to avoid scratches on the surface of the plate and strip caused by the rigid roller, thereby improving the shape and surface quality of the plate and strip after rolling.

[0106] Example 2

[0107] According to the rolling method capable of realizing axial variable tension described in Example 1, a steel plant is used to simulate the rolling of silicon steel with micro-medium wave as the target plate shape of axial variable tension. The target residual stress corresponding to the target plate shape of silicon steel is Distribution Fig.13 As shown in the figure, the control of silicon steel edge drop is prone to coupling the control of silicon steel flatness and edge drop. After the actual control of silicon steel edge drop, the residual stress measured by the rolling mill exit flatness meter is like Fig.14 shown.

[0108] Since the tension roller hydraulic or pneumatic bag cannot provide compressive stress for the strip, the compressive stress required by the strip is not compensated. After correction by the negative value zeroing method, the tensile stress that needs to be compensated locally is: , whose distribution is as follows Fig.15 shown.

[0109] near The positive pressure value at the position is linearly interpolated or quadratically interpolated according to the slope change law to obtain the compensation stress after interpolation. , and then obtain the tensile stress that needs to be compensated locally after correction for , distributed as Fig.16 shown.

[0110] When the interpolation method is used to compensate for the residual stress of the plate strip, according to the formula Calculated pressure in each section of hydraulic or pneumatic bladder Considering that there is a certain distance between the tension roller system and the exit of the deformation zone, according to the Saint-Venant principle, the longitudinal compensation stress of the strip will decay at a position far away from the tension roller. Considering the influence of distance attenuation, the compensation value is set to The calculated stress axial distribution of each section of the tension roller liquid / air pressure bag is as follows: Fig.17 shown.

[0111] In order to further analyze the influence of the tension roller along the roller axial tension on the strip stress, finite element analysis was performed. All simulated strips are made of steel strips with an elastic modulus of 205000MPa, a Poisson's ratio of 0.29, a thickness of 1mm, and a width of 1200mm. The strips on both sides of the strip are symmetrically distributed about the center of the tension roller, and the single-side length of the strip is 1200mm. The strip unit type is hexahedron, with a unit size of 30mm*30mm*0.25mm. A solid roller with a radius of 150mm is used as the tension roller, a steel elastic roller, an elastic modulus of 205000MPa, and a Poisson's ratio of 0.29.

[0112] When the wrap angle of the strip to the tension roller is 150°, the two ends of the strip are fixed and constrained, the tension roller follows Fig.17 The radial support force of each section is shown The calculated Mises equivalent stress state cloud diagram of the strip steel acting on the strip steel cladding surface is as follows: Fig.18 As shown in the figure, the Mises equivalent stress of the strip is relatively uniform at a position far from the center of the tension roller, while the fluctuation is more obvious at a position close to the center of the tension roller. The longitudinal tensile stress distribution of the strip at a distance of 200 mm and 1000 mm from the end face of the strip is further extracted, which is similar to the longitudinal residual stress. ,like Fig.19 and Fig. 20 At a position 200 mm away from one end of the strip, far from the center of the tension roller, due to a certain attenuation near the center of the tension roller, the longitudinal tensile stress distribution of the strip appears asymmetric as shown in the figure. Fig.16 The distribution law is similar, but due to a certain attenuation, at a position 1000mm away from the end face of the strip, near the center of the tension roller, and far away from the center of the tension roller, the longitudinal stress attenuation of the strip is close to the mid-wave stress distribution, and the edge stress correction effect is close to Fig.16 Distribution pattern.

[0113] When the wrap angle of the strip to the tension roller is 150°, the longitudinal tensile stress applied to both ends of the strip is equal to . is the average tensile stress, for Fig.16 The local non-uniform residual stress is shown in Figure 1. The pressure distribution law of each section of the tension axis is calculated as follows: Fig.21As shown in the figure, the pressure of the strip on the two ends of the tension roller is the greatest, and it is almost zero at the 1 / 4 width position of the roller body. The pressure on the roller surface in the center of the roller body is relatively small. The distribution of the tension roller surface pressure along the axial direction is shown in the figure. Fig. 22 ,and Fig.17 The axial distribution of the stress of the liquid / air bag of the tension roller is similar. The relationship between the longitudinal tensile stress of the plate strip and the radial pressure of the tension roller approximately satisfies , verifying the effectiveness of the control model.

[0114] In order to further study the coupling effect of the longitudinal tension of the strip and the variable support force of the tension roller under different wrap angle conditions, a tensile stress equal to , is the average tensile stress, for Fig.16 The local non-uniform residual stress shown is used to simulate the actual double quarter wave shape. Fig.17 The radial support forces of each section shown act on the strip cladding surface, and a simulation model is carried out to analyze the ability of the tension roller to repair and adjust the double quarter-wave plate shape.

[0115] When the wrap angle of the strip to the tension roller is 120°, the Mises stress cloud diagram of the strip under the coupling of different radial support forces of the tension roller and the longitudinal stress of the strip is as follows: Fig.23 As shown in the figure, near the center of the tension roller, the strip Mises equivalent stress is relatively uniform, and near the two ends of the tension roller, the equivalent stress is larger and fluctuates more obviously. The pressure distribution law of each section of the tension axis is calculated as follows: Fig.24 As shown in the figure, the pressure of the strip on the two end surfaces and the center of the tension roller is relatively large, while it is very small at the 1 / 4 width position of the roller. The relationship between the longitudinal tensile stress of the strip and the radial pressure of the tension roller is approximately satisfied , further verifying the effectiveness of the control model.

[0116] Further extraction of the longitudinal tensile stress distribution along the strip at a distance of 200 mm and 1000 mm from one end of the strip is similar to the longitudinal residual stress. ,like Fig.25 and Fig.26 At a position 200 mm from the end of the strip and far from the center of the tension roller, the longitudinal tensile stress distribution of the strip is as follows: Fig.16 The distribution law is similar. After removing the average tensile stress, the value is close to Fig.14 The double quarter wave stress distribution law shows that the tension roller has a weakened ability to correct the actual residual stress of the strip at a farther position. At a position 200 mm away from the end of the strip, close to the center of the tension roller, the longitudinal tensile stress distribution of the strip is as follows Fig.16 The distribution law is similar. At a distance of 1000 mm from the end of the strip, the longitudinal stress of the strip is corrected. After removing the average tensile stress, the longitudinal stress of the strip is attenuated to a value close to Fig.13 The distribution law of the target micro-medium wave stress shows that the tension roller can effectively compensate for the influence of the double quarter wave of the strip, so that the longitudinal tensile stress of the strip near the tension roller is close to the target micro-medium wave plate shape, and the longitudinal tensile stress distribution of the plate and strip at the two positions is compared, which indirectly shows that the tension compensation model needs to consider the attenuation effect.

[0117] When the wrap angle of the strip to the tension roller is 135°, the Mises stress cloud diagram of the strip under the coupling of different radial support forces of the tension roller and the longitudinal stress of the strip is as follows: Fig. 27 As shown in the figure, the Mises equivalent stress of the strip is relatively uniform near the center of the tension roller, while the equivalent stress is larger and the fluctuation is more obvious near the two ends of the tension roller. Fig.28 The pressure distribution law of each section of the tension axis is similar to Fig.24 , but under the condition of relative wrap angle of 120°, the roller surface pressure is slightly reduced. The longitudinal tensile stress distribution of the strip at 200mm and 1000mm from one end of the strip is as follows Fig.29 , Fig.30 As shown, similar to the longitudinal residual stress ,and Fig.25 and Fig.26 similar.

[0118] When the wrap angle of the strip to the tension roller is 150°, the Mises stress cloud diagram of the strip under the coupling of different radial support forces of the tension roller and the longitudinal stress of the strip is as follows: Fig.31 As shown in the figure, the Mises equivalent stress of the strip is relatively uniform near the center of the tension roller, while the equivalent stress is larger and the fluctuation is more obvious near the two ends of the tension roller. Fig.32 The pressure distribution law of each section of the tension axis is similar to Fig.24 and Fig.28 Similar, but under the relative wrap angle of 120° and 135°, the roller surface pressure is further reduced. The distribution of tensile stress along the longitudinal direction of the strip at 200mm and 1000mm from one end of the strip is as follows Fig.33 , Fig.34 As shown, similar to the longitudinal residual stress ,and Fig.25 and Fig.29 and Fig.26 and Fig.30 similar.

[0119] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A rolling method capable of achieving axial variable tension, characterized in that: The rolling method is implemented by a tension roller device for axially variable tension rolling, the tension roller device for axially variable tension rolling comprising a tension roller core shaft (2), an expandable bag (1) is provided on the outer side of the tension roller core shaft (2), the expandable bag (1) is arranged in sections along the axial direction of the tension roller core shaft (2), and a swivel joint (3) is provided at each end of the tension roller core shaft (2), and a plurality of connection holes are provided on the swivel joint (3). The tension roller core shaft (2) is provided with a plurality of channels inside, one end of the channels is connected to the inside of the segmented expandable bag (1), and the other end is connected to the connection hole of the rotary joint (3), the rotary joint (3) is connected to a control valve group, the control valve group is connected to a pressure source, the pressure source is a hydraulic oil source (6) or an air pressure source (7), the pressure source provides pressure medium to the segmented expandable bag (1) outside the tension roller core shaft (2) through the control valve group and the rotary joint (3), so as to realize different pressure control in the segmented expandable bag (1), the rolling method comprises the following steps: S1: each section of the expandable bladder (1) is directly contacted with the plate strip to be processed, so that the plate strip forms a wrap angle of 30° to 150° around the tension roller device; S2: Use a shape meter to measure the actual shape of the strip at the mill exit and obtain the measured longitudinal residual stress , according to the target residual stress of the plate Calculate the longitudinal residual stress that needs to be compensated by the tension roller equipment, that is, the tensile stress that needs to be compensated locally in the strip , the tensile stress that needs to be compensated locally in the plate Target residual stress of plate and strip And measured longitudinal residual stress Satisfies the following relationship: （1） Since the expandable bag (1) cannot provide compressive stress to the strip, it does not compensate for the compressive stress required by the strip. The tensile stress required to be compensated locally in the strip after correction is for （2） or close to The positive pressure value at the position is linearly interpolated or quadratically interpolated according to the slope change law to obtain the tensile stress that needs to be compensated in the local area of ​​the plate after interpolation. , and then obtain the corrected tensile stress that needs to be compensated locally on the strip for （3） S3: Based on the tensile stress that needs to be compensated locally in the plate strip in S2 , calculate the pressure required to be provided in each section of the expandable bladder (1) , the pressure required to be provided in each section of the expandable bladder (1) The tensile stress that needs to be compensated locally on the strip satisfy （4） In the formula, h is the strip thickness, mm; It is half of the wrap angle of the strip around the tension roller. is the local width of the strip, mm, is the nominal radius of the tension roller, mm; is the tensile stress that needs to be compensated locally in the plate strip, MPa, is the internal pressure of the capsule, MPa; is the integration variable; Thus, the pressure required to be provided in each section of the expandable bladder (1) is obtained. The tensile stress that needs to be compensated locally on the strip The relationship is: （5） S4: Pressure medium is provided to the segmented expandable bladder (1) outside the tension roller core shaft (2) through the control valve group and the rotary joint (3), so that the pressure inside each segment of the expandable bladder (1) reaches the required pressure calculated in S3. ; S5: By changing the supporting force of each section of the expandable bladder (1) on the surface of the plate and strip, different tensile stresses are constructed in the width direction of the plate and strip, and variable tension rolling operation is performed.

2. A rolling method capable of achieving axial variable tension according to claim 1, characterized in that: Consider the distance attenuation effect and increase the compensation coefficient According to the negative value zeroing method, the pressure inside the hydraulic or pneumatic bag of each section of the tension roller equipment is obtained. The size is: （6） Or use the interpolation method to obtain the pressure in each section of the hydraulic or pneumatic bag of the tension roller The size is: （7） In the formula, in the formula, σ r is the pressure inside the air bag, MPa.

3. A rolling method capable of achieving axial variable tension according to claim 1, characterized in that: Each segment of the expandable bladder (1) is internally connected with two channels, one channel is an input channel (9) for the pressure medium, and the other channel is an output channel (8) for the pressure medium. The input channel (9) for the pressure medium is connected to the rotary joint (3) on the left side of the tension roller core shaft (2), and the output channel (8) for the pressure medium is connected to the rotary joint (3) on the right side of the tension roller core shaft (2).

4. A rolling method capable of achieving axial variable tension according to claim 1, characterized in that: The control valve group comprises a pressure reducing valve group (4) and a back pressure valve group (5). The pressure reducing valve group (4) is connected to the rotary joint (3) on the left side of the tension roller core shaft (2). The pressure reducing valve group (4) comprises a P1 pressure reducing valve, a P2 pressure reducing valve, a P3 pressure reducing valve, and a P4 pressure reducing valve. n Pressure reducing valves, a total of n groups of pressure reducing valves, n is the number of segments of the inflatable bag (1), P n The pressure reducing valve is connected to the nth segment of the expandable bag (1), the back pressure valve group (5) is connected to the rotary joint (3) on the right side of the tension roller core shaft (2), and the back pressure valve group (5) includes a P 1 Back pressure valve, P 2 Back pressure valve, P 3 Back pressure valve…P n Back pressure valve, a total of n groups of back pressure valves, n is the number of segments of the expandable bag (1), P n The back pressure valve is connected to the nth segment of the expandable bladder (1).

5. A rolling method capable of achieving axial variable tension according to claim 4, characterized in that: The pressure reducing valve group (4) is connected to the pressure source, and the back pressure valve group (5) is connected to a hydraulic oil tank or an air silencer system.

6. A rolling method capable of achieving axial variable tension according to claim 4, characterized in that: The P n Pressure reducing valve with the P n Back pressure valve differential pressure connection.

7. A rolling method capable of achieving axial variable tension according to claim 4, characterized in that: The pressure reducing valve group is a pilot electromagnetic proportional pressure reducing valve group with feedback or an electro-hydraulic pressure servo valve, and the back pressure valve group is a pilot electromagnetic proportional sequence valve group with feedback or an electro-hydraulic pressure servo valve.

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