Automatic head straightening and strip threading control method based on strip steel mechanical properties

Abstract

The invention discloses a strip steel mechanical property-based automatic head straightening and strip threading control method, which comprises the following steps of: 1, acquiring actual straightening machine roller diameter data, strip steel mechanical property data and strip steel thickness specification data, executing simulation and measurement and calculation inspection by using a GBTD algorithm, and fitting to obtain straightening machine strip threading roller gap basic parameters; forming a straightening machine compensation coefficient according to the strip steel strength grade, and establishing a straightening machine process model regulation table; 2, calling and substituting a straightener roll gap calculation formula based on the data obtained in the step 1 to obtain an actual roll gap set value of the straightener; and 3, the process control system sends the actual roll gap set value, obtained in the step 2, of the straightening machine to the electrical automatic control system, and the electrical automatic control system conducts control according to set data so that the strip steel head can be straightened and straightened to reach the prediction precision. Manual intervention of operators can be reduced, and the working efficiency, the automation efficiency and the production quality are improved.

Description

Technical Field

[0001] This invention relates to the field of control technology for hot-rolled strip leveling mills, specifically to a control method for automatic straightening and threading of strips based on the mechanical properties of strip steel. Background Technology

[0002] Currently, hot-rolled steel strip products are widely used in various industries, such as engineering machinery, transportation vehicles, containers, and construction. Different products have significantly different material properties, which makes it easy for the strip to tilt upwards or downwards during the threading process at the leveling mill. This can prevent the strip from passing smoothly through the leveling mill, and in severe cases, the strip may impact the roll surface, causing bulges or depressions. This affects the surface quality of the strip during rolling and restricts the stable and normal production efficiency of the leveling mill. Summary of the Invention

[0003] The purpose of this invention is to provide a control method for automatic straightening head threading based on the mechanical properties of strip steel. This method can effectively combine the elastic-plastic deformation characteristics of metal materials, the precision management of the straightening machine, and the preset value of the straightening machine roll gap model, thereby reducing manual intervention by operators and achieving the goal of improving work efficiency, automation efficiency, and production quality.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A control method for automatic straightening head threading based on the mechanical properties of steel strip includes the following steps: Step 1: Collect actual straightener roll diameter data, strip mechanical property data, and strip thickness specification data. Then, use the GBTD algorithm to perform simulation and calculation verification, fit the basic parameters of the straightener roll gap, and form the straightener compensation coefficient according to the strip strength grade. Step 2: Based on the data obtained in Step 1, call and substitute the formula for calculating the roll gap of the straightener to obtain the actual roll gap setting value of the straightener; Step 3: The process control system sends the actual roll gap setting value of the straightener obtained in Step 2 to the electrical automation control system, which then controls the straightener according to the set data to ensure that the straightening head of the strip reaches the predicted accuracy.

[0005] Furthermore, in step two, the formula for calculating the roll gap of the straightening machine includes the following: Formula 1: Calculated value of roller gap in straightening machine = * * +α* * + ; In Formula 1: Expressed as the strip thickness coefficient; Expressed as strip thickness, in mm; This represents the roll position allocation ratio adjusted according to the strip thickness; Expressed as the coefficient of linear expansion; Expressed as the roller spacing, = 1.15 * , The diameter of the straightening roller is in mm. This represents the difference between the feeding temperature and the standard temperature, where the standard temperature is set to 20℃. Formula 2: Actual roll gap setting value of straightener = Calculated roll gap value of straightener * Compensation coefficient of straightener.

[0006] Furthermore, the calculated range of the roller gap of the straightening machine is required to be: 0 ≤ Fset ≤ 12, in mm.

[0007] Furthermore, in step one, a process model specification table for the straightening machine is established based on the data obtained in step one.

[0008] Furthermore, in step one, if new specifications or new strengths of steel are introduced, it is necessary to first establish fuzzy matching index rules for the corresponding specification table.

[0009] The beneficial effects of this invention are: 1. This invention can reduce operator intervention, effectively improve work efficiency, automation efficiency and production quality. By looking up the coefficients in the specification table through strip mechanical property data and strip thickness specification data, the calculation logic of the straightening machine model is improved, the automatic control capability of the hot rolling leveling unit in the strip threading process is improved, the straightening control accuracy of the strip head is enhanced, and the phenomenon of collision and puncture of the rollers caused by the strip tilting upward or downward is avoided.

[0010] 2. The method of this invention enables the process control system to set production parameters more accurately. After the model is put into use, the belt threading rhythm is improved from 102 seconds to 65 seconds, and the occurrence of roller collisions or punctures is reduced from an average of 5 times per shift to 0 times. The average time for grinding the roller surface due to roller damage is reduced by 35 minutes per shift, thereby achieving economic benefits of increased production and efficiency. At the same time, it reduces the safety risks of personnel entering the machine frame to grind the rollers. It is applicable to various strip steel finishing production lines, effectively reducing manual labor load and improving work efficiency and product quality. Attached Figure Description

[0011] Figure 1 This is a flowchart of an automatic straightening and strap-threading control method based on the mechanical properties of steel strip, according to the present invention.

[0012] Figure 2 This is an example diagram of the process model specification table for the straightening machine in an embodiment of the present invention.

[0013] Figure 3 This is a data table diagram of the roller position allocation ratio in an embodiment of the present invention. Detailed Implementation

[0014] The technical solutions in the embodiments of the present invention will now be described with reference to the accompanying drawings.

[0015] like Figure 1 As shown, this invention provides a control method for automatic straightening head threading based on the mechanical properties of steel strip, comprising the following steps: Step 1: Collect actual straightener roll diameter data, strip mechanical property data, and strip thickness specification data. Using the GBTD algorithm, perform simulation and calculation verification to obtain the basic parameters of the strip threading roll gap for the #2 and #4 roll groups of the straightener. Simultaneously, generate straightener compensation coefficients based on the strip strength grade, and then establish a straightener process model specification table. Since new specifications and strengths of steel may appear during production, resulting in a lack of accurately indexed data in the straightener process model specification table, it is necessary to develop fuzzy matching index rules for the straightener process model specification table, as shown below: The data in the procedure table that is closest to the diameter of the straightening roll is used as a subsequent index; The data in the specification table that matches the diameter of the straightening roll and is closest to the actual yield strength is used as a subsequent index. Find the data in the specification table that best matches the straightening roll diameter, actual yield strength, and is closest to the actual strip thickness; Finally, a process model specification table for the straightening machine is generated, as shown in the table below. Figure 2 As shown.

[0016] Step Two: Based on the data obtained in Step One, call and substitute the formula for calculating the roll gap of the straightener to obtain the actual roll gap setting value for roll group #2 and roll group #4 of the straightener. The formula for calculating the roll gap of the straightener includes the following: Formula 1: Calculated value of roller gap in straightening machine = * * +α* * + ; In Formula 1: Expressed as the strip thickness coefficient, based on the current design capacity of the hot rolling leveling unit. Set it to 0.28; Expressed as strip thickness, in mm; This represents the roll position allocation ratio adjusted according to the strip thickness. For example, the current roll position allocation ratio of the straightening machine... Figure 3 As shown, it should be noted that roller groups 1, 3, and 5 of the straightening machine are all fixed roller groups and do not participate in the roller position allocation adjustment; Expressed as the coefficient of linear expansion, α is set to 12.2 * 10⁻⁶. -6 ; Expressed as the roller spacing, = 1.15 * , The diameter of the straightening roller is in mm. This represents the difference between the feeding temperature and the standard temperature, where the standard temperature is set to 20℃. The calculated range of the roller gap for the straightening machine is: 0 ≤ Fset ≤ 12, in mm; Formula 2: Actual roll gap setting value of straightener = Calculated roll gap value of straightener * Compensation coefficient of straightener.

[0017] Step 3: The process control system sends the actual roll gap setting values ​​of roll group 2 and roll group 4 obtained in step 2 to the electrical automation control system. The electrical automation control system then controls the strip head according to the set data to ensure that the strip head straightening head achieves the predicted accuracy.

[0018] Based on the control methods described above, the present invention will be further illustrated below through two specific application examples.

[0019] Example 1: 1. Select steel coils from a hot rolling leveling mill production line, steel grade IV5949E7. Based on the actual collected data, the specific details include: straightening roll diameter of 259mm, yield strength of 380MPa, strip thickness of 1.862mm, strip width of 1120mm, and feeding temperature of 60℃. 2. Based on the formula for calculating the roll gap of the straightener, the calculated roll gap value of the #2 roll group of the straightener is 2.11361mm, and the calculated roll gap value of the #4 roll group is 2.18446mm; 3. Since this steel grade belongs to the 400MPa strength grade, it is necessary to multiply the original calculated value by the straightening machine compensation coefficient of 0.6. The actual roll gap setting value of the 2# roll group of the straightening machine is 1.26817mm, and the actual roll gap setting value of the 4# roll group is 1.31067mm.

[0020] Example 2: 1. Select steel coils from a hot rolling leveling mill production line, steel grade EU7815A6. Based on the actual collected data, the specific details include: straightening roll diameter of 259mm, yield strength of 700MPa, strip thickness of 5.881mm, strip width of 1575mm, and feeding temperature of 70℃. 2. Based on the formula for calculating the roll gap of the straightener, the calculated roll gap value of the #2 roll group of the straightener is 6.48513mm, and the calculated roll gap value of the #4 roll group is 6.76676mm; 3. Since this steel grade belongs to the 700MPa strength grade, it is necessary to multiply the original calculated value by the straightening machine compensation coefficient of 0.8. The actual roll gap setting value of the 2# roll group of the straightening machine is 5.188104mm, and the actual roll gap setting value of the 4# roll group is 5.413408mm.

[0021] After this invention was put into use in the hot rolling leveling unit, the threading rhythm was improved from 102 seconds to 65 seconds, the occurrence of roller collisions and punctures was reduced from an average of 5 times per shift to 0 times, and the average time for repairing the roller surface due to roller damage was reduced by 35 minutes per shift, directly increasing the production capacity of the leveling unit by 50 tons per shift.

[0022] The above content is only used to illustrate the technical solution of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A control method for automatic straightening head threading based on the mechanical properties of strip steel, characterized in that, Includes the following steps: Step 1: Collect actual straightener roll diameter data, strip mechanical property data, and strip thickness specification data. Then, use the GBTD algorithm to perform simulation and calculation verification, fit the basic parameters of the straightener roll gap, and form the straightener compensation coefficient according to the strip strength grade. Step 2: Based on the data obtained in Step 1, call and substitute the formula for calculating the roll gap of the straightener to obtain the actual roll gap setting value of the straightener; Step 3: The process control system sends the actual roll gap setting value of the straightener obtained in Step 2 to the electrical automation control system, which then controls the straightener according to the set data to ensure that the straightening head of the strip reaches the predicted accuracy.

2. The automatic straightening head and belt threading control method based on the mechanical properties of strip steel according to claim 1, characterized in that, In step two, the formula for calculating the roll gap of the straightening machine includes the following: Formula 1: Calculated value of roller gap in straightening machine = * * +α* * + ; In Formula 1: Expressed as the strip thickness coefficient; Expressed as strip thickness, in mm; This represents the roll position allocation ratio adjusted according to the strip thickness; Expressed as the coefficient of linear expansion; Expressed as the roller spacing, = 1.15 * , The diameter of the straightening roller is in mm. This represents the difference between the feeding temperature and the standard temperature, where the standard temperature is set to 20℃. Formula 2: Actual roll gap setting value of straightener = Calculated roll gap value of straightener * Compensation coefficient of straightener.

3. The automatic straightening head and belt threading control method based on the mechanical properties of strip steel according to claim 2, characterized in that, The calculated range of the roller gap for the straightening machine is required to be: 0 ≤ Fset ≤ 12, in mm.

4. The automatic straightening head and belt threading control method based on the mechanical properties of strip steel according to any one of claims 1 to 3, characterized in that, In step one, a process model specification table for the straightening machine is established based on the data obtained in step one.

5. The automatic straightening head and belt threading control method based on the mechanical properties of strip steel according to claim 4, characterized in that, In step one, if new specifications or strengths of steel are introduced, it is necessary to first establish fuzzy matching index rules for the corresponding specification table.

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