Method for measuring, calculating and interlocking inner diameter of mandrel of uncoiling machine

Abstract

The invention relates to the technical field of mandrel inner diameter measurement and core coil correction, and particularly discloses an uncoiler mandrel inner diameter measurement calculation and linkage method, which comprises the following steps: signal acquisition: according to the uncoiler expansion and shrinkage mechanical design principle, installing a photoelectric sensor I and a photoelectric sensor II on an uncoiler; a measuring point of the photoelectric sensor I is vertically downwards opposite to the outer edge of the mandrel and is beyond the width of the production line; the measuring point of the photoelectric sensor II is aligned with the plane center of the rotary joint and is on the same horizontal line so as to measure the displacement distance of the mandrel; the diameter deviation is converted into length deviation, wherein the diameter deviation of the core pulling roll and the second-stage lower part is converted into the length deviation; establishing an interlocking method for the uncoilers; according to the invention, the production accident that the strip tail is easy to slip into the inlet loop during the production of the'core-pulling roll 'is fundamentally avoided, the applicable production capacity of the cold rolling continuous production line on upstream raw materials is improved, and the stability of the production line is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of core shaft inner diameter measurement and core removal coil correction, and particularly relates to a method for measuring, calculating and interlocking the inner diameter of a mandrel of an uncoiler. Background Art

[0002] The raw material coils of pickling, tempering, galvanizing cold rolling continuous production lines are steel coils produced by the upstream hot rolling production line. They are uncoiled, straightened, scrap cut, welded (the tail of the previous coil and the head of the next coil are welded by a welder to complete continuous production), and further processed on the uncoiler through transportation equipment. The inner diameter and length of the raw materials are important data for material tracking in the cold rolling continuous production line. In actual production, when there are defects in the raw material coils (such as edge cracks, tower shape, hem, wrinkles, etc.) that affect coil loading, product quality or pose a risk of strip breakage, they will be manually cut offline. The coils processed manually are commonly called "core removal coils". These "core removal coils" will cause the distortion of the original data of the inner diameter and length, directly resulting in inaccurate tracking of the strip tail and weld seam during the uncoiling process. It is necessary to verify manually before the coil is put on the line, and manually track and intervene in advance after the coil is put on the line. If the detection and intervention are not timely, it will cause inaccurate tracking of the fixed tail, the strip tail slipping into the inlet loop and being unable to be welded, and the production cannot continue, resulting in production stoppage (it is necessary to manually use a threading rope to pull the strip tail from the inlet loop to the welding position of the welder for welding, and the treatment time for each accident is not less than 3 hours), seriously affecting normal production.

[0003] There is no interlocking and detection design concept for producing "core removal coils" in cold rolling continuous production lines at home and abroad. When producing "core removal coils", it is necessary to verify manually before the coil is put on the line, and manually track and intervene in advance after the coil is put on the line. The efficiency is low, and it is easy to occur the accident that the strip tail slips into the inlet loop, seriously restricting the stable production of the production line. Therefore, a set of methods for measuring, calculating and interlocking the inner diameter of the mandrel of the uncoiler in the coil continuous production line is designed and invented to solve the problems of low efficiency of manual verification before the coil is put on the line and affecting the stable production of the production line. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a method for measuring, calculating and interlocking the inner diameter of a mandrel of an uncoiler. By collecting sensor signals and using calculation methods, the actual inner diameter value is calculated and participates in the interlocking and tracking calculations, avoiding the accident that the "core removal coil" causes inaccurate fixed tail and slips into the loop.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a method for measuring, calculating and interlocking the inner diameter of a mandrel of an uncoiler, including the following steps:

[0006] S1. Signal acquisition: According to the mechanical design principle of the diameter expansion and contraction of the uncoiler, a photoelectric sensor I and a photoelectric sensor II are installed on the uncoiler;

[0007] S2. Installation and calculation of the photoelectric sensor I:

[0008] S21. Installation requirements: The measurement point of Photoelectric Sensor 1 is vertically downward and directly opposite to the outer edge of the mandrel, and it is outside the width of the production line.

[0009] S22. The calculation formula is: D r = 2(0 - L r ) + C;

[0010] S3. Installation and calculation of Photoelectric Sensor 2:

[0011] S31. Installation requirements: The measurement point of Photoelectric Sensor 2 is aligned with the center of the rotary joint plane and on the same horizontal line, aiming to measure the displacement distance of the mandrel.

[0012] S32. The calculation formula is: D r = D min + tan∠A * L * 2 + C,

[0013] Or D r = D min +(D max - D min ) / (L max - L min ) * (L r - L min );

[0014] S4. Conversion of diameter deviation to length deviation: Convert the diameter deviation of the "core - removed coil" and the secondary - issued diameter deviation to length deviation. The calculation formula: DL = {π * (((D r / 2) 2 -(Ds / 2) 2 ) / TH};

[0015] S5. Method for establishing the interlock of the uncoiler.

[0016] Specifically, the uncoiler in step S1 includes a mandrel and a fixed base. The mandrel adopts a wedge - type expanding and contracting diameter structure. The mandrel is connected to the output shaft of the reducer, and the input shaft of the reducer is connected to the rotary joint.

[0017] Specifically, the bottom of the reducer is installed on the sliding base. The sliding base is slidably connected to the fixed base. A sliding power mechanism is installed on the fixed base. The sliding power mechanism is connected to the sliding base. The sliding power mechanism uses a hydraulic cylinder or a motor. The hydraulic cylinder or the motor drives the sliding base to move and drives the mandrel to move, driving the sector plate that cooperates with the inclined wedge sliding surface inside the mandrel to expand or contract radially. Photoelectric Sensor 1 and Photoelectric Sensor 2 measure and collect signals for the expanding and contracting action distance of the mandrel.

[0018] Specifically, the first photoelectric sensor in step S2 is fixedly installed on the speed reducer through a bracket. Since cracks will appear on the surface of the mandrel when it is in the expanded diameter state, it is necessary to add a stop iron in the arc surface area on the driving side of the rotating mandrel and add positioning and limiting on the reel base. The positioning and limiting are perpendicular to the first photoelectric sensor in a straight line, or the arc surface data is only obtained through programming without installing the positioning and limiting to ensure the acquisition of the plane area signal during the rotation of the mandrel.

[0019] Specifically, in the calculation formula of step S2, D r : The actual inner diameter value measured and calculated in the state of having a coil and expanded diameter;

[0020] D min : The inner diameter value measured by the measuring tool in the reduced diameter state;

[0021] L max : The value of the photoelectric sensor in the reduced diameter state, that is, the measured height from the installation position to the mandrel;

[0022] 0: The value of the position from the photoelectric sensor to the center of the mandrel calculated in the reduced diameter state (L max +D min / 2), and this value only needs to be calculated once;

[0023] L r : The measured value of the photoelectric sensor when the mandrel has a coil and is in the expanded diameter state;

[0024] C: Compensation value.

[0025] Specifically, the first calculation formula of the second photoelectric sensor in step S3 is that the mechanical structure of the inclined wedge and the sector plate are composed of multiple groups of symmetric and equal right-angled triangle components, and knowing the angle of ∠A, then the proportional coefficient of the hydraulic cylinder displacement and the diameter is calculated using the right-angled triangle function, and the actual diameter is calculated through the actual measured value;

[0026] In formula one, tan∠A = a opposite side / b adjacent side = R H / L, and the angle data of ∠A is obtained through measurement or design drawings;

[0027] D r : The actual inner diameter value measured and calculated in the state of having a coil and expanded diameter;

[0028] D min : The inner diameter value measured by the measuring tool in the reduced diameter state;

[0029] L: Hydraulic cylinder displacement;

[0030] R H : Sector plate displacement height, mandrel radius change height;

[0031] C; Compensation value.

[0032] Specifically, the second calculation formula of the photoelectric sensor two in step S3 is: if the mechanical structure cannot be calculated by the first trigonometric function formula, measure (maximum inner diameter - minimum inner diameter) / displacement change measured by the photoelectric sensor two with a measuring tool, calculate the proportionality coefficient, and calculate the change of the actual inner diameter value through the actual numerical change difference of the photoelectric sensor;

[0033] In formula two, D r : The actual inner diameter value measured and calculated in the state of having a coil and expanding diameter;

[0034] D min : The inner diameter value measured by the measuring tool in the state of reducing diameter;

[0035] D max : The inner diameter value measured by the measuring tool in the state of no steel coil and expanding diameter;

[0036] L min : The value measured by the photoelectric sensor in the state of reducing diameter;

[0037] L max : The value measured by the photoelectric sensor in the state of no steel coil and expanding diameter;

[0038] The above are the data recorded by one-time measurement;

[0039] L r : The real-time measurement value of the photoelectric sensor when the mandrel expands with a coil;

[0040] C: Compensation value.

[0041] Specifically, in the formula of step S4, D r : The actual inner diameter value measured and calculated in the state of having a coil and expanding diameter;

[0042] D s : The inner diameter of the steel coil issued at the second level, that is, the standard inner diameter of the raw material coil;

[0043] TH: The thickness of the steel coil issued at the second level, that is, the standard thickness of the raw material coil;

[0044] DL: The deviation between the actual length and the length of the raw material coil;

[0045] LS; Allowable diameter tolerance.

[0046] Specifically, the specific steps of the interlocking method established by the uncoiler in step S5 include:

[0047] S51. After the uncoiler finishes winding and expanding the diameter, compare the actual inner diameter value D r with the original value D s issued at the second level plus the allowable tolerance. When D r > (D sWhen it is +LS, the HMI human-machine interface prompts "core extraction coil", and the operating console buzzer alarms;

[0048] S52. Automatically calculate the length deviation and add this value to the deceleration length before tail flick and the set tail length tracking value;

[0049] S53. When the uncoiler tails to the slitting shear + the slitting shear operates, immediately and automatically synchronize the tail tracking position to the slitting shear;

[0050] S54. When the uncoiler tails to the welding machine sequence start + the grating signal in front of the slitting shear is lost, immediately and automatically synchronize the tail tracking position to the slitting shear.

[0051] The present invention has the following beneficial effects:

[0052] The designed inner diameter measurement, calculation and interlocking method of the uncoiler mandrel of the present invention, by combining the mechanical mechanism of the uncoiler mandrel, installs the photoelectric sensor at a specific position for signal acquisition, calculates the actual inner diameter value through a calculation method, and calculates the inner diameter deviation and length deviation values through comparison with the standard inner diameter value of the raw material. This value is used for "core extraction coil" alarm detection and for related interlocking and tracking correction, fundamentally avoiding the production accident that the tail of the strip is likely to slip into the inlet loop during the production of "core extraction coil", improving the applicable production capacity of the cold rolling continuous production line for upstream raw materials, and improving the production line stability. Description of the Drawings

[0053] Figure 1 is a schematic structural diagram of installing a photoelectric sensor on the uncoiler.

[0054] Figure 2 is a sectional view showing the internal inclined wedge type diameter expansion and contraction structure of the mandrel.

[0055] In the figure: 1 - steel coil; 2 - mandrel; 3 - reducer; 4 - sliding base; 5 - rotary joint; 6 - fixed base; 7 - sliding power mechanism; 8 - photoelectric sensor one; 9 - photoelectric sensor two; 10 - sector plate. Detailed Embodiments

[0056] The following will further clearly and completely describe in detail the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] As Figure 1 - Figure 2 shown, a method for measuring, calculating and interlocking the inner diameter of an uncoiler mandrel includes the following steps:

[0058] 1. Signal acquisition: According to the mechanical design principle of the diameter expansion and contraction of the uncoiler, a photoelectric sensor 1 and a photoelectric sensor 2 are installed on the uncoiler. The uncoiler includes a mandrel 2 and a fixed base 6. The mandrel 2 adopts a wedge-type diameter expansion and contraction structure. The mandrel 2 is connected to the output shaft of the reducer 3, and the input shaft of the reducer 3 is connected to the rotary joint 5.

[0059] The bottom of the reducer 3 is installed on the sliding base 4. The sliding base 4 is slidably connected to the fixed base 6. A sliding power mechanism 7 is installed on the fixed base 6. The sliding power mechanism 7 is connected to the sliding base 4. The sliding power mechanism 6 adopts a hydraulic cylinder or a motor. The hydraulic cylinder or the motor drives the sliding base 4 to move and drives the mandrel 2 to move, driving the sector plate 10 that cooperates with the inclined wedge sliding surface inside the mandrel 2 to perform radial diameter expansion or contraction. The photoelectric sensor 1 8 and the photoelectric sensor 2 9 measure and collect the signal of the diameter expansion and contraction action distance of the mandrel 2.

[0060] 2. Installation and calculation of the photoelectric sensor 1 8.

[0061] ① Installation requirements: The measurement point of the photoelectric sensor 1 8 is vertically downward and directly opposite the outer edge of the mandrel 2, and outside the width of the production line. The photoelectric sensor 1 8 is fixedly installed on the reducer 3 through a bracket. Since cracks will appear on the surface of the mandrel 2 in the diameter-expanded state, it is necessary to add a stop iron in the arc surface area on the driving side of the rotating mandrel 2 and add a positioning limit on the reel base. The positioning limit and the photoelectric sensor 1 8 are in a straight line perpendicular to each other, or the positioning limit is not installed and only the arc surface data is obtained through programming to ensure the acquisition of the signal in the plane area during the rotation of the mandrel.

[0062] ② The calculation formula is: D r =2(0 - L r ) + C;

[0063] D r : The actual inner diameter value measured and calculated in the diameter-expanded state with a coil;

[0064] D min : The inner diameter value measured by the measuring tool in the diameter-contracted state;

[0065] L max : The value of the photoelectric sensor in the diameter-contracted state, that is, the measurement height from the installation position to the mandrel;

[0066] 0: The value of the photoelectric sensor to the center position of the mandrel calculated in the diameter-contracted state (L max + D min / 2), and this value only needs to be calculated once;

[0067] L r : The value measured by the photoelectric sensor when the mandrel is diameter-expanded with a coil;

[0068] C: Compensation value. Regularly use a calibration sleeve (metal ring) with a known diameter equal to the inner diameter of the raw material to check and correct the actual measurement and calculation values, eliminating errors caused by factors such as mechanical clearance and stroke changes.

[0069] 3. Installation and calculation of photoelectric sensor II 9:

[0070] ① Installation requirements: Photoelectric sensor II 9 is installed on the fixed base 6 through a bracket. The measurement point of photoelectric sensor II 9 is aligned with the center of the rotary joint plane and on the same horizontal line, aiming to measure the displacement distance of the mandrel.

[0071] ② Calculation method: The first calculation formula of photoelectric sensor II is that the mechanical structure of the inclined wedge and the sector plate consists of multiple groups of symmetric and equal right triangle components, and knowing the angle of ∠A, then use the right triangle function to calculate the proportional coefficient of the hydraulic cylinder displacement and the diameter, and calculate the actual diameter through the actual measurement value.

[0072] The first calculation formula is: D r =D min +tan∠A*L*2+C;

[0073] In formula one, tan∠A = opposite side of a / adjacent side of b = R H / L, and the angle data of ∠A is obtained through measurement or mechanical drawing design;

[0074] D r : The actual inner diameter value measured and calculated in the state of having a coiling diameter;

[0075] D min : The inner diameter value measured by the measuring tool in the state of reduced diameter;

[0076] L: Hydraulic cylinder displacement;

[0077] R H : Displacement height of the sector plate, change height of the mandrel radius;

[0078] C: Compensation value. Regularly use a calibration sleeve (metal ring) with a known diameter equal to the inner diameter of the raw material to check and correct the actual measurement and calculation values, eliminating errors caused by factors such as mechanical clearance and stroke changes.

[0079] If the mechanical structure cannot be calculated through the trigonometric function formula one, measure (maximum inner diameter - minimum inner diameter) / displacement change measured by photoelectric sensor II with a measuring tool, calculate the proportional coefficient, and calculate the change of the actual inner diameter value through the actual numerical change difference of the photoelectric sensor.

[0080] The second calculation formula is: D r =D min +(D max -Dmin ) / (L max -L min )*(L r -L min );

[0081] In Formula 2, D r : The actual inner diameter value measured and calculated under the state of having coil expansion diameter;

[0082] D min : The inner diameter value measured by the measuring tool under the state of diameter reduction;

[0083] D max : The inner diameter value measured by the measuring tool under the state of no coil expansion diameter;

[0084] L min : The value measured by the photoelectric sensor under the state of diameter reduction;

[0085] L max : The value measured by the photoelectric sensor under the state of no coil expansion diameter;

[0086] The above are the data recorded by one-time measurement;

[0087] L r : The real-time measurement value of the photoelectric sensor when the mandrel has coil expansion;

[0088] C: Compensation value. Regularly use a calibration sleeve (metal ring) with a known diameter equal to the inner diameter of the raw material to check and correct and supplement the actual measurement and calculation value to eliminate errors caused by factors such as mechanical clearance and stroke change.

[0089] 4. Conversion of diameter deviation to length deviation: Convert the diameter deviation of the "core-removed coil" issued by the second level to length deviation. The calculation formula: DL = {π * ((D r / 2) 2 -(Ds / 2) 2 ) / TH};

[0090] In the formula, D r : The actual inner diameter value measured and calculated under the state of having coil expansion diameter;

[0091] D s : The inner diameter of the coil issued by the second level, that is, the standard inner diameter of the raw material coil;

[0092] TH: The thickness of the coil issued by the second level, that is, the standard thickness of the raw material coil;

[0093] DL: The length deviation between the actual and the raw material coil;

[0094] LS; Allowable value of diameter out-of-tolerance.

[0095] 5. Method for establishing interlock of the uncoiler. The specific steps include:

[0096] ① After the expanding diameter of the decoiler for loading the coil is completed, the actual inner diameter value D r is compared with the original value D sent from the second level s plus the allowable deviation value. When D r >(D s +LS), the HMI human-machine interface will prompt "core-removing coil" and the operating console buzzer will alarm.

[0097] ② Automatically calculate the length deviation and add this value to the deceleration length before tailing-off and the tracking value of the tailing-off length.

[0098] ③ When the decoiler tails off to the slitter + the slitter operates, immediately and automatically synchronize the tail tracking position to the slitter.

[0099] ④ When the decoiler tails off to the sequence control start of the welder + the grating signal in front of the slitter is lost, immediately and automatically synchronize the tail tracking position to the slitter.

[0100] Since the decoiler is designed in a tension control mode, no relevant interlocks need to be added to the tension control part.

[0101] The present invention combines the mechanical mechanism of the decoiler mandrel, installs the photoelectric sensor at a specific position for signal acquisition. Converts the collected data into the actual inner diameter value through a calculation method, and calculates the inner diameter deviation value and the length deviation value through comparison with the raw material standard data. For the first time in the same industry, the "core-removing coil" alarm and tracking correction function are proposed and developed. Fundamentally, it avoids the production accident that the tail of the strip is likely to slip into the inlet loop during the production of "core-removing coil". Self-made calibration sleeves of various sizes matching the raw materials, and regularly conduct data verification to ensure the accuracy and effectiveness of the data. Improve the applicable production capacity of the cold rolling continuous production line for upstream raw materials.

[0102] The present invention is not limited to the above embodiments. Anyone should know that the structural changes made under the inspiration of the present invention, as long as they have the same or similar technical solutions as the present invention, all fall within the protection scope of the present invention.

[0103] The technologies, shapes, and structures not described in detail in the present invention are all well-known technologies.

Claims

1. A method for measuring, calculating and chaining the inner diameter of a mandrel of an unwinding machine, characterized in that: The following steps are involved: S1. Signal acquisition: According to the mechanical design principle of the uncoiler expansion and contraction, photoelectric sensor 1 and photoelectric sensor 2 are installed on the uncoiler; S2. Installation and calculation of photoelectric sensor 1: S21. Installation requirements: The measuring point of the photoelectric sensor 1 is vertically downward facing the outer edge of the mandrel and outside the width of the production line; S22, the calculation formula is: D r =2(0-L r )+C; S3. Installation and calculation of photoelectric sensor 2: S31. Installation requirements: The measuring point of the second photoelectric sensor should be aligned with the center of the rotating joint plane and on the same horizontal line, in order to measure the displacement distance of the core shaft; S32, the calculation formula is: D r =D min +tan∠A*L*2+C, or D r =D min +(D max -D min ) / (L max -L min )*(L r -L min ); S4. Convert diameter deviation to length deviation: Convert the diameter deviation of the "core roll" and the secondary issued diameter deviation to length deviation. The calculation formula is: DL = {π*((D r / 2) 2 -(Ds / 2) 2 ) / TH}; S5. The unwinding machine establishes a chain method.

2. The method for measuring, calculating and chaining the inner diameter of the mandrel of the unwinding machine according to claim 1, characterized in that: The uncoiler in step S1 comprises a mandrel and a fixed base, the mandrel adopts an inclined wedge-type expansion and contraction structure, the mandrel is connected to the output shaft of the reducer, and the input shaft of the reducer is connected to the rotary joint.

3. The method for measuring, calculating and interlocking the inner diameter of the mandrel of the unwinding machine according to claim 2, characterized in that: The bottom of the reducer is installed on a sliding base, the sliding base is slidably connected to the fixed base, a sliding power mechanism is installed on the fixed base, the sliding power mechanism is connected to the sliding base, the sliding power mechanism adopts a hydraulic cylinder or a motor, the hydraulic cylinder or the motor drives the sliding base to move and drives the core shaft to move, drives the fan-shaped plate matched with the inclined wedge sliding surface inside the core shaft to radially expand or shrink, and the photoelectric sensor 1 and the photoelectric sensor 2 measure the expansion and contraction action distance of the core shaft and collect signals.

4. The method for measuring, calculating and interlocking the inner diameter of the mandrel of the unwinding machine according to claim 3, characterized in that: The photoelectric sensor in step S2 is fixedly installed on the reducer through a bracket. Since cracks will appear on the surface of the core shaft when the core shaft is in an expanded diameter state, it is necessary to add a stopper iron to the arc surface area on the rotating core shaft transmission side and a positioning limit on the drum base. The positioning limit is in a straight line perpendicular to the photoelectric sensor, or the positioning limit is not installed and only the arc surface data is obtained through programming to ensure that the plane area signal is collected during the rotation of the core shaft.

5. The method for measuring, calculating and chaining the inner diameter of the mandrel of the unwinding machine according to claim 1, characterized in that: In the calculation formula of step S2, D r : The actual inner diameter value measured and calculated under the coil expansion state; D min : The inner diameter value measured by the gauge in the reduced diameter state; L max : The value of the photoelectric sensor in the reduced diameter state, that is, the measured height from the installation position to the core shaft; 0: The value of the photoelectric sensor to the center of the mandrel calculated in the reduced diameter state (L max +D min / 2), this value only needs to be calculated once; L r : The photoelectric sensor measures the value when the core shaft expands and curls; C: Compensation value.

6. The method for measuring, calculating and chaining the inner diameter of the mandrel of the unwinding machine according to claim 1, characterized in that: The calculation formula of the photoelectric sensor 2 in step S3 is: the mechanical structure of the wedge and the fan plate is composed of two groups of symmetrical and equal right triangle components, and the angle of ∠A is known. The proportional coefficient of the displacement of the hydraulic cylinder and the diameter is calculated using the right triangle function, and the actual diameter is calculated by the actual measurement value; In formula 1, tan∠A = a opposite side / b adjacent side = R H / L, ∠A angle data are obtained by measurement or design of mechanical drawings; D r : The actual inner diameter value measured and calculated under the coil expansion state; D min : The inner diameter value measured by the gauge in the reduced diameter state; L: displacement of hydraulic cylinder; R H : Displacement height of the sector plate, change height of the core shaft radius; C; compensation value.

7. The method for measuring, calculating and chaining the inner diameter of the mandrel of the unwinding machine according to claim 1, characterized in that: The calculation formula 2 of the photoelectric sensor 2 in step S3 is: if the mechanical structure cannot be calculated by the trigonometric formula 1, the (maximum inner diameter-minimum inner diameter) / photoelectric sensor 2 displacement change is measured by a measuring tool, the proportional coefficient is calculated, and the actual inner diameter change is calculated by the difference of the actual value change of the photoelectric sensor; Formula 2 D r : The actual inner diameter value measured and calculated under the coil expansion state; D min : The inner diameter value measured by the gauge in the reduced diameter state; D max : The inner diameter value measured by the measuring tool without the expansion of the steel coil; L min : The measured value of the photoelectric sensor in the reduced diameter state; L max : The photoelectric sensor measurement value when there is no coil expansion; The above is a one-time measurement and recording data; L r : The photoelectric sensor measures the value in real time when the core shaft expands and curls; C: Compensation value.

8. The method for measuring, calculating and chaining the inner diameter of the mandrel of the unwinding machine according to claim 1, characterized in that: In the formula of step S4, D r : The actual inner diameter value measured and calculated under the coil expansion state; D s : The inner diameter of the secondary issued steel coil, i.e. the standard inner diameter of the raw material coil; TH: Secondary issued steel coil thickness, i.e. standard thickness of raw material coil; DL: actual length deviation from raw material roll; LS: allowable value of diameter deviation.

9. The method for measuring, calculating and chaining the inner diameter of the mandrel of the unwinding machine according to claim 1, characterized in that: The specific steps of the method for establishing a chain of uncoilers in step S5 include: S51, after the coiling diameter is increased on the uncoiler, the actual inner diameter value D r The original value D sent by the second level s Add the tolerance allowable value for comparison. When D r >(D s +LS), the HMI human-machine interface prompts "core roll" and the console buzzer alarms; S52, automatically calculating the length deviation, and adding the value to the speed reduction length before tail swing and the tail fixed length tracking value; S53, when the uncoiler swings its tail to the slitting shear + slitting shear action, it will automatically synchronize the tail tracking position to the slitting shear immediately; S54, when the grating signal is lost before the unwinder tail swings to the welding machine sequential control start + slitting shear, the tail tracking position is automatically synchronized to the slitting shear.

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