A method for pre-positioning and speed control of an aluminum strip seam head

Abstract

This invention relates to a method for pre-positioning and speed control of the stitching head of aluminum strip, comprising a PLC control system, a stitching machine, a first clamping roller group, a crescent-shaped shear, a second clamping roller group, and a disc shear arranged sequentially along the aluminum strip conveying direction. The crescent-shaped shear is equipped with a laser rangefinder A for detecting the stitching head of the aluminum strip, a photoelectric detection device for detecting the edge position of narrower aluminum strips, and a displacement sensor for measuring the actual position of the cutting head. Both the laser rangefinder A and the photoelectric detection device are mounted on the crescent-shaped shear head. An encoder for detecting the conveying length of the strip is located at the clamping roller group. A laser rangefinder B is mounted on the disc shear to detect when the stitching head of the aluminum strip reaches the entry position. The crescent-shaped shear position is pre-positioned according to the incoming material width, thereby shortening the process connection time. Speed ​​control ensures that the stitching head, after being cut by the crescent-shaped shear, stops precisely at the disc shear, improving production efficiency.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy strip processing technology, and in particular to a method for pre-positioning and speed control of the stitching head of aluminum strip, which is especially suitable for the continuous rolling and trimming process of aluminum strip. Background Technology

[0002] In the continuous rolling production of aluminum strip, after the two rolls of strip are spliced ​​by the sewing machine, they need to go through two processes in sequence: crescent shear and disc shear. First, the crescent shear punches crescent-shaped notches on the edges of the strip on both sides of the sewing head. Then, the strip is conveyed to the disc shear by the pinch roller. The disc shear uses the crescent notch as the cutting point of the cutting blade to complete the precise positioning before cutting the edge.

[0003] However, in the existing control process, the crescent-shaped scissor head only begins to move from the outermost retraction position to the strip cutting position after the sewing head has actually reached the equipment position. The cutting action is only performed after the head has reached the correct position, and after cutting, the scissor head retracts, while the strip continues to move downstream towards the disc shear. Throughout this process, the scissor head movement and the strip conveying are sequential, resulting in long waiting times between processes and hindering the improvement of overall production line efficiency. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for pre-positioning and speed control of aluminum strip stitching heads that is simple to implement and has low modification costs, thereby shortening the process connection time, reducing energy consumption caused by frequent start-stop, and achieving high-efficiency, low-energy continuous production.

[0005] This invention is implemented using the following scheme: A method for pre-positioning and speed control of the aluminum strip sewing head, comprising a PLC control system, a sewing machine, a first pinch roller group, a crescent-shaped shear, a second pinch roller group, and a disc shear arranged sequentially along the aluminum strip conveying direction. The blade on the crescent shear is driven by a hydraulic cylinder. The crescent shear is equipped with a laser rangefinder A for detecting the aluminum strip sewing head, a photoelectric detection device for detecting the edge position of the narrower aluminum strip, and a displacement sensor for measuring the actual position of the blade. The laser rangefinder A and the photoelectric detection device are both mounted on the crescent shear head. An encoder for detecting the conveying length of the strip is provided at the pinch roller group. A laser rangefinder B is used on the disc shear to detect when the aluminum strip sewing head reaches the entry position. The method includes the following steps: S1, Parameter Preset: The PLC control system obtains the total conveying distance S from the crescent shear to the disc shear, and the maximum permissible speed v of the process. max The following parameters are considered: constant acceleration / deceleration a (production line setting equal acceleration and deceleration capabilities); fixed offset L between the beam of the photoelectric detection device and the center of the crescent-shaped scissor head; cutting depth D; thickness W1 and width d1 of the currently online aluminum strip; thickness W2 and width d2 of the next roll of aluminum strip; preset safety gap value G; and the PLC control system compares d1 and d2, recording the larger width as d.max ; S2, Cutter head pre-positioning: The PLC control system determines the precise position P of the narrow aluminum strip edge based on the photoelectric detection device. edge Calculate the target position Pt of the cutter head based on the preset safety clearance value G. edge +G; When the PLC control system receives the aluminum strip stitching signal, it immediately drives the left and right blades of the crescent shears to move from the outermost position to the Pt position, pre-positioning the blades at the Pt position. The purpose is to ensure that no matter whether the actual strip width in front of the stitching head is d1 or d2, its edge will not interfere with or collide with the blades. At this time, the blades are in standby mode and have not yet come into contact with the edge of the narrower strip that is about to be cut. S3. Seam Head Position Detection and Edge Position Reading: When the laser rangefinder A on the crescent shears detects that the seam head has moved directly below the crescent shear head, the aluminum strip moves in a jogging manner, and the speed gradually approaches zero, so it can be considered stationary relative to the blade head. At this time, the PLC control system cancels the pre-positioning mode with Pt as the target and switches to the fine-tuning mode. The PLC control system drives the blade head to move slowly towards the center of the aluminum strip. When the photoelectric detection device signal changes, the change signal is immediately sent to the PLC control system. The PLC control system then reads the current value of the displacement sensor and obtains the actual edge position P of the blade head relative to the center line of the equipment. This position is the edge position of the narrower strip. S4. Cutting Depth Fine-tuning and Shearing Execution: The PLC control system calculates the fine-tuning distance ΔS=L+D based on the fixed offset L between the photoelectric detection device beam and the cutter head center and the cutting depth D. It then drives the left and right cutters to move ΔS further towards the center of the aluminum strip, ensuring that the cutter head's cutting point accurately covers the overlapping area of ​​the two rolls of strip. After the cutter head is advanced into position, the hydraulic system's solenoid valve locks to maintain the cutter head's position. At this time, the photoelectric detection device is in a constant state where it is completely blocked by the aluminum strip. Subsequently, the PLC sends a "Shearing Ready" signal, and the hydraulic cylinder executes the downward shearing action. After completion, the cutter head retracts to the outermost position for positioning. S5. Conveying Section Speed ​​Planning: After receiving the signal "Shearing complete, cutter head retracts for positioning," the PLC control system initiates the conveying control of the aluminum strip from the crescent shear to the disc shear. During the conveying process, the aluminum strip is required to accelerate uniformly from rest to its maximum speed v. max Then, it decelerates uniformly to a standstill and precisely reaches the disc shear; the PLC control system executes a three-stage speed planning accordingly: since the acceleration and deceleration distances are set to be equal, the formula S is given. 加 =S 减 =v 2 max / 2a; Distance S of the uniform speed segment 匀 =S-(S 加 +S 减 )=Sv2 max / a; The running times for each stage are as follows: Acceleration time t1 = v max / a, deceleration time t3-t2= v max / a, uniform motion time t2-t1=S 匀 / v max ; S6. Speed ​​Setting and Stage Switching: The PLC control system sends a speed setting command to the frequency converter and switches according to the following logic: Acceleration Phase: After startup, the PLC control system linearly increases the speed setpoint at a rate of V=a×t until the set maximum speed v is reached. max ; Uniform speed phase: when the real-time velocity v now Reaching v max At that time, the PLC control system locks the speed setpoint to v. max Keep running; Deceleration phase: When the PLC control system calculates the remaining conveying distance S in real time... rem Satisfy S rem ≤v now When ² / (2a), immediately switch to deceleration setpoint mode, and set the speed setpoint according to V. target = √(2×a×S rem The calculation output is configured with acceleration and deceleration ramp times to ensure a smooth and shock-free speed transition process. S7. Seam Head Detection and Zero Point Marking: When the seam head passes the laser rangefinder B irradiation point at the disc shear, due to the sudden change in thickness at the seam head, the laser rangefinder value jumps instantaneously. After the PLC control system detects this jump signal, the PLC control system immediately clears or freezes the current encoder cumulative value and marks the position as the absolute zero point, which serves as the reference point for subsequent conveying distance calculation. S8. Real-time Remaining Distance Calculation and Deceleration Trigger: With the laser rangefinder B fixed in position and the stitching head marked as the zero point, the fixed distance from this zero point to the disc scissor edge is denoted as L. 固定 The strip continues to be conveyed forward, and the PLC control system calculates the conveyed distance S in real time after the stitching head leaves the laser rangefinder via the encoder on the pinch roller assembly. 走 The real-time remaining distance between the suture head and the disc scissor edge is S. rem =L 固定 -S 走 Meanwhile, the PLC control system adjusts the current speed according to v. now Real-time calculation of the minimum distance S required for deceleration dec = v now ² / (2a); when S rem ≤S decAt that moment, the PLC control system immediately issues a uniform deceleration command to ensure that the aluminum strip can come to a smooth stop before reaching the disc shear. S9, Precise End-of-Line Stop Control: When the PLC control system detects S... rem When the distance is ≤0.5m, an ultra-low speed command is forcibly sent to the frequency converter. The aluminum strip smoothly decreases to this speed (i.e., the preset ultra-low speed, generally 0.005m / s~0.01m / s) within 2~3s of passing through the frequency converter ramp and slowly advances; the PLC control system monitors the remaining distance in real time through the encoder; when S is detected... rem When ≤ΔS1, where ΔS1 is the pre-stop compensation value, ranging from 0 to 0.8 mm, it is used to compensate for the system delay from the issuance of the electrical command to the complete action of the mechanical brake. This value is finely calibrated by the operator before each shift by jogging test cuts and according to the actual stop position. The PLC control system immediately cuts off the inverter enable signal and activates the pinch roller brake, and the aluminum strip is immediately locked. The positioning error can be controlled within ±0.2 mm.

[0006] Furthermore, two sets of photoelectric detection devices are respectively installed on the inner side of the blade head on the operating side and the transmission side of the crescent shears. The photoelectric detection device includes a photoelectric transmitter and a photoelectric receiver. The infrared beam emitted by the photoelectric transmitter is perpendicular to the running direction of the aluminum strip, and the photoelectric receiver receives the reflection. When the edge of the aluminum strip blocks the beam, a signal jump occurs (light path unobstructed → light path blocked). The PLC control system captures the jump signal and triggers the position reading command.

[0007] Furthermore, the displacement sensor is installed on the slide rail of the crescent-shaped scissor head to measure the actual position of the scissor head in real time and transmit the data to the PLC control system.

[0008] Furthermore, there are two laser rangefinders A, which are installed on the inside of the blade head on the operating side and the transmission side of the crescent shear, respectively; and one laser rangefinder B, which is installed on the frame at the entrance of the disc shear.

[0009] Furthermore, the laser rangefinder detects the seam head in steps S3 and S7 as follows: The laser rangefinder collects the distance value X between itself and the surface of the aluminum strip. When the laser rangefinder detects the change in distance value ΔX > W1 + W2 three times in a row within 3 seconds, it indicates that the seam head has been detected.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The present invention can drive the cutter head to move to the target area in advance before the sewing head reaches the crescent shear based on the changes in strip width, real-time position and sewing head position information, and with the help of the trapezoidal speed curve, achieve smooth acceleration and deceleration and precise positioning of the strip from the crescent shear to the disc shear section, thereby shortening the process connection time, reducing the energy consumption caused by frequent start and stop, and realizing high-efficiency and low-energy continuous production.

[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through specific embodiments and related drawings. Attached Figure Description

[0012] Figure 1 This is a structural layout diagram of an embodiment of the present invention; Figure 2 Arrangement diagram of laser rangefinder and photoelectric detection device on the operating side blade of crescent scissors in this embodiment of the invention; Figure 3 A schematic diagram of the suture incision state at the crescent-shaped scissors in an embodiment of the present invention; Figure 4 Speed ​​control curve diagram of an embodiment of the present invention; The numbers in the diagram are explained as follows: 1-sewing machine, 2-first pinch roller group, 3-crescent shears, 4-second pinch roller group, 5-disc shears, 6-laser rangefinder B, 7-displacement sensor, 31-laser rangefinder A, 32-photoelectric measuring device, 33-crescent shear head. Detailed Implementation

[0013] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0014] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0015] like Figures 1-4 As shown, a method for pre-positioning and speed control of the aluminum strip sewing head includes a PLC control system, a sewing machine 1, a first clamping roller group 2, a crescent-shaped shear 3, a second clamping roller group 4, and a disc shear 5 arranged sequentially along the aluminum strip conveying direction. The blade on the crescent shear is driven by a hydraulic cylinder. The crescent shear is equipped with a laser rangefinder A31 for detecting the aluminum strip sewing head, a photoelectric detection device 32 for detecting the edge position of the narrower aluminum strip, and a displacement sensor 7 for measuring the actual position of the blade. The laser rangefinder A and the photoelectric detection device are both mounted on the crescent shear head and move together with the blade. An encoder for detecting the conveying length of the strip is provided at the clamping roller group. A laser rangefinder B is used on the disc shear to detect when the aluminum strip sewing head reaches the entry position. The method includes the following steps: S1. Parameter preset: The PLC control system obtains the total conveying distance S (unit: m) from the crescent shear to the disc shear and the maximum allowable speed v of the process. max (Unit: m / s), constant acceleration / deceleration a (unit: m / s², production line setting acceleration and deceleration capabilities are equal), fixed offset L between the beam of the photoelectric detection device and the center of the crescent-shaped scissor head (unit: mm), cutting depth D (unit: mm), thickness W1 and width d1 of the current online aluminum strip (unit: mm), thickness W2 and width d2 of the next roll of aluminum strip (unit: mm), preset safety gap value G (unit: mm), the PLC control system compares d1 and d2, and records the larger width as d max .

[0016] S2, Cutter head pre-positioning: The PLC control system determines the precise position P of the narrow aluminum strip edge based on the photoelectric detection device. edge Calculate the target position Pt of the cutter head based on the preset safety clearance value G. edge +G; When the PLC control system receives the aluminum strip stitching signal, it immediately drives the left and right blades of the crescent shears to move from the outermost position to the Pt position. The safety gap value G ranges from 0.5mm to 1.0mm, preferably 0.5mm, to ensure that the edge of the wide strip does not touch the blade or block the light switch, and to avoid interference and collision between the blade and the strip. Pre-positioning the blade at the Pt position is to ensure that regardless of whether the actual strip width in front of the stitching head is d1 or d2, its edge will not interfere with or collide with the blade; at this time, the blade is in a standby state and has not yet come into contact with the edge of the narrower strip to be cut.

[0017] S3. Seam Head Position Detection and Edge Position Reading: When the laser rangefinder A on the crescent-shaped shears detects that the seam head has moved directly below the crescent-shaped shear head, the aluminum strip moves in a jogging mode with a speed range of 0.01m / s to 0.05m / s, gradually approaching zero, and can be considered stationary relative to the blade head. At this time, the PLC control system releases the pre-positioning mode with Pt as the target and switches to fine-tuning mode. The PLC control system drives the blade head to move slowly towards the center of the aluminum strip (speed 0.01m / s to 0.05m / s). When the photoelectric detection device signal changes (from light-transmitting to light-blocking), the change signal is immediately sent to the PLC control system. The PLC control system then reads the current value of the displacement sensor to obtain the actual edge position P of the blade head relative to the center line of the equipment. This position is the edge position of the narrower strip. This serves as the data basis for subsequent fine-tuning, avoiding the blade head from cutting empty due to positioning based on the edge of the wider strip, and thus preventing the strip at the notch from breaking under tension.

[0018] S4. Fine-tuning of Cut Depth and Shearing Execution: The PLC control system calculates the fine-tuning distance ΔS = L + D (unit: mm) based on the fixed offset L between the photoelectric detection device beam and the cutter head center and the cut depth D. It then drives the left and right cutters to move ΔS further towards the center of the aluminum strip, ensuring that the cutter head's cutting point accurately covers the overlapping area of ​​the two rolls of strip. After the cutter head is advanced into position, the hydraulic system's solenoid valve locks to maintain the cutter head's position. At this time, the photoelectric detection device is in a constant state where it is completely blocked by the aluminum strip. Subsequently, the PLC control system sends a "Shearing Ready" signal, and the hydraulic cylinder executes the downward shearing action. After completion, the cutter head retracts to the outermost position for positioning. The cut depth D ranges from 3 mm to 8 mm, specifically determined based on the strip widths d1 and d2.

[0019] S5. Conveying Section Speed ​​Planning: After receiving the signal "Shearing complete, cutter head retracts for positioning," the PLC control system initiates the conveying control of the aluminum strip from the crescent shear to the disc shear. During the conveying process, the aluminum strip is required to accelerate uniformly from rest to its maximum speed v. max Then, it decelerates uniformly to a standstill and precisely reaches the disc shear; the PLC control system executes a three-stage speed planning accordingly: since the acceleration and deceleration distances are set to be equal, the formula S is given. 加 =S 减 =v 2 max / 2a; Distance S of the uniform speed segment 匀 =S-(S 加 +S 减 )=Sv 2 max / a; The running times for each stage are as follows: Acceleration time t1 = v max / a, deceleration time t3-t2= v max / a, uniform motion time t2-t1=S 匀 / v max .

[0020] S6. Speed ​​Setting and Stage Switching: The PLC control system sends a speed setting command to the frequency converter and switches according to the following logic: Acceleration Phase: After startup, the PLC control system linearly increases the speed setpoint at a rate of V=a×t until the set maximum speed v is reached. max ; Uniform speed phase: when the real-time velocity v now Reaching v max At that time, the PLC control system locks the speed setpoint to v. max Keep running; Deceleration phase: When the PLC control system calculates the remaining conveying distance S in real time... rem Satisfy S rem ≤v nowWhen ² / (2a), immediately switch to deceleration setpoint mode, and set the speed setpoint according to V. target = √(2×a×S rem The calculation output is configured with acceleration and deceleration ramp times to ensure a smooth and shock-free speed switching process.

[0021] S7. Seam Head Detection and Zero Point Marking: When the seam head passes the laser rangefinder B irradiation point at the disc shear, due to the sudden change in thickness at the seam head, the laser rangefinder value jumps instantaneously. After the PLC control system detects this jump signal, the PLC control system immediately clears or freezes the current encoder cumulative value and marks the position as the absolute zero point, which serves as the reference point for subsequent conveying distance calculation.

[0022] S8. Real-time Remaining Distance Calculation and Deceleration Trigger: With the laser rangefinder B fixed in position and the stitching head marked as the zero point, the fixed distance from this zero point to the disc scissor edge is denoted as L. 固定 (Unit: m); The strip continues to be conveyed forward, and the PLC control system calculates the conveyed distance S in real time after the stitching head leaves the laser rangefinder via the encoder on the pinch roller group. 走 (Unit: m), then the real-time remaining distance between the suture head and the disc scissor edge is S. rem =L 固定 -S 走 Meanwhile, the PLC control system adjusts the current speed according to v. now Real-time calculation of the minimum distance S required for deceleration dec = v now ² / (2a) (unit: m); when S rem ≤S dec At that moment, the PLC control system immediately issues a uniform deceleration command to ensure that the aluminum strip can come to a smooth stop before reaching the disc shear.

[0023] S9, Precise End-of-Line Stop Control: When the PLC control system detects S... rem When the distance is ≤0.5m, an ultra-low speed command is forcibly sent to the frequency converter. The aluminum strip smoothly decreases to this speed within 2~3 seconds as it passes the ramp of the frequency converter and slowly advances. The PLC control system monitors the remaining distance in real time through the encoder. When S is detected... rem When ≤ΔS1, where ΔS1 is the pre-stop compensation value, ranging from 0 to 0.8 mm, it is used to compensate for the system delay from the issuance of the electrical command to the complete action of the mechanical brake. This value is finely calibrated by the operator before each shift by jogging test cuts and according to the actual stop position. The PLC control system immediately cuts off the inverter enable signal and activates the pinch roller brake, and the aluminum strip is immediately locked. The positioning error can be controlled within ±0.2 mm.

[0024] The above method ensures that the crescent-shaped shear head is pre-positioned until the sewing signal is received, effectively reducing the waiting time between shearing processes and improving production line efficiency. A strategy combining trapezoidal speed control with end-effector ultra-low-speed crawling and pre-stop brakes achieves precise stopping of the strip material from the crescent shear to the disc shear.

[0025] In this embodiment, two sets of photoelectric detection devices are respectively installed on the inner side of the blade head on the operating side and the transmission side of the crescent shears. The photoelectric detection device includes a photoelectric transmitter and a photoelectric receiver. The infrared beam emitted by the photoelectric transmitter is perpendicular to the running direction of the aluminum strip, and the photoelectric receiver receives the reflection. When the edge of the aluminum strip blocks the beam, a signal jump occurs (light path unobstructed → light path blocked). The PLC control system captures the jump signal and triggers the position reading command.

[0026] In this embodiment, the displacement sensor is installed on the slide of the crescent-shaped scissor head to measure the actual position of the scissor head in real time and transmit the data to the PLC control system.

[0027] In this embodiment, there are two laser rangefinders A, which are installed on the inside of the blade head on the operating side and the transmission side of the crescent shear, respectively; there is one laser rangefinder B, which is installed on the frame at the entrance of the disc shear.

[0028] In this embodiment, the laser rangefinder detects the stitch head in steps S3 and S7 as follows: The laser rangefinder collects the distance value X between itself and the surface of the aluminum strip. When the laser rangefinder detects the change in distance value ΔX > W1 + W2 three times in a row within 3 seconds, it indicates that a stitch head has been detected.

[0029] This invention is simple to implement, has low modification costs, and possesses good practicality and promotional value. By pre-positioning the crescent-shaped shear head, the long stroke movement of the shear head is advanced to be executed after the sewing signal is received, effectively reducing the waiting time between shearing processes and improving production line efficiency. By adopting a strategy of trapezoidal speed control combined with ultra-low speed crawling at the end and pre-stop brake, the strip material is accurately stopped from the crescent shear to the disc shear, with a stable positioning accuracy controlled within ±0.2mm. The PLC control system calibrates the shear head position in real time and dynamically adjusts the speed based on the remaining distance of the strip material, forming a closed-loop control with clear logic and rapid response, reducing the need for manual intervention.

[0030] Unless otherwise stated, if any of the technical solutions disclosed in this invention specify a numerical range, then the disclosed numerical range is a preferred numerical range. Anyone skilled in the art should understand that the preferred numerical range is merely one among many feasible numerical values ​​that has a more obvious or representative technical effect. Because there are many numerical values, it is impossible to list them all. Therefore, this invention discloses only some numerical values ​​to illustrate the technical solutions of this invention. Furthermore, the numerical values ​​listed above should not constitute a limitation on the scope of protection of this invention.

[0031] If this invention discloses or relates to mutually fixedly connected components or structural parts, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0032] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0033] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for pre-positioning and speed control of an aluminum strip sewing head, comprising a PLC control system, a sewing machine, a first pinch roller group, a crescent-shaped shear, a second pinch roller group, and a disc shear arranged sequentially along the aluminum strip conveying direction, characterized in that: The crescent-shaped shear is equipped with a laser rangefinder A for detecting the stitching head of the aluminum strip, a photoelectric detection device for detecting the edge position of the narrower aluminum strip, and a displacement sensor for measuring the actual position of the cutter head. Both the laser rangefinder A and the photoelectric detection device are mounted on the head of the crescent-shaped shear. An encoder for detecting the conveying length of the strip is installed at the pinch roller assembly. A laser rangefinder B is used on the disc shear to detect when the stitching head of the aluminum strip reaches the entry position. The method includes the following steps: S1, Parameter Preset: The PLC control system obtains the total conveying distance S from the crescent shear to the disc shear, and the maximum permissible speed v of the process. max The following parameters are considered: constant acceleration / deceleration a, fixed offset L between the beam of the photoelectric detection device and the center of the crescent-shaped scissor head, cutting depth D, current online aluminum strip thickness W1 and width d1, next roll aluminum strip thickness W2 and width d2, preset safety gap value G. The PLC control system compares d1 and d2, and records the larger width as d. max ; S2, Cutter head pre-positioning: The PLC control system determines the precise position P of the narrow aluminum strip edge based on the photoelectric detection device. edge Calculate the target position Pt of the cutter head based on the preset safety clearance value G. edge +G; When the PLC control system receives the aluminum strip stitching signal, it immediately drives the left and right blades of the crescent shears to move from the outermost position to the Pt position, pre-positioning the blades at the Pt position. At this time, the blades are in standby mode and have not yet come into contact with the edge of the narrower strip that is about to be cut. S3. Seam Head Position Detection and Edge Position Reading: When the laser rangefinder A on the crescent scissors detects that the seam head has moved directly below the crescent scissor head, the aluminum strip moves in a jogging manner, and the speed gradually approaches zero, so it can be considered stationary relative to the blade head. At this time, the PLC control system drives the blade head to move slowly towards the center of the aluminum strip. When the photoelectric detection device signal changes, the change signal is immediately sent to the PLC control system. The PLC control system then reads the current value of the displacement sensor to obtain the actual edge position P of the blade head relative to the center line of the equipment. S4. Cutting Depth Fine-tuning and Shearing Execution: The PLC control system calculates the fine-tuning distance ΔS=L+D based on the fixed offset L between the photoelectric detection device beam and the cutter head center and the cutting depth D, and drives the left and right cutters to move ΔS further towards the center of the aluminum strip, so that the cutter head cutting point accurately covers the overlapping area of ​​the two rolls of strip; after the cutter head is advanced into place, the hydraulic system solenoid valve locks to keep the cutter head position locked. At this time, the photoelectric detection device is in a constant state completely blocked by the aluminum strip. Subsequently, the hydraulic cylinder performs the downward shearing action. After completion, the cutter head retracts to the outermost position for positioning. S5. Conveying Section Speed ​​Planning: The PLC control system initiates the conveying control of the aluminum strip from the crescent shear to the disc shear. During the conveying process, the aluminum strip is required to accelerate uniformly from a standstill to its maximum speed v. max Then, it decelerates uniformly to a standstill and precisely reaches the disc shear; the PLC control system executes a three-stage speed planning accordingly: since the acceleration and deceleration distances are set to be equal, the formula S is given. 加 =S 减 =v 2 max / 2a; Distance S of the uniform speed segment 匀 =S-(S 加 +S 减 )=Sv 2 max / a; The running times for each stage are as follows: Acceleration time t1 = v max / a, deceleration time t3-t2= v max / a, uniform motion time t2-t1=S 匀 / v max ; S6. Speed ​​Setting and Stage Switching: The PLC control system sends a speed setting command to the frequency converter and switches according to the following logic: Acceleration Phase: After startup, the PLC control system linearly increases the speed setpoint at a rate of V=a×t until the set maximum speed v is reached. max ; Uniform speed phase: when the real-time velocity v now Reaching v max At that time, the PLC control system locks the speed setpoint to v. max Keep running; Deceleration phase: When the PLC control system calculates the remaining conveying distance S in real time... rem Satisfy S rem ≤v now When ² / (2a), immediately switch to deceleration setpoint mode, and set the speed setpoint according to V. target = √(2×a×S rem The calculation output is configured with acceleration and deceleration ramp times to ensure a smooth and shock-free speed transition process. S7. Suture Head Detection and Zero Point Marking: When the suture head passes the laser rangefinder B illumination point at the disc shear, the PLC control system immediately clears or freezes the current encoder cumulative value and marks the position as the absolute zero point, which serves as the reference point for subsequent conveying distance calculation. S8. Real-time Remaining Distance Calculation and Deceleration Trigger: With the laser rangefinder B fixed in position and the stitching head marked as the zero point, the fixed distance from this zero point to the disc scissor edge is denoted as L. 固定 The strip continues to be conveyed forward, and the PLC control system calculates the conveyed distance S in real time after the stitching head leaves the laser rangefinder via the encoder on the pinch roller assembly. 走 The real-time remaining distance between the suture head and the disc scissor edge is S. rem =L 固定 -S 走 Meanwhile, the PLC control system adjusts the current speed according to v. now Real-time calculation of the minimum distance S required for deceleration dec = v now ² / (2a); when S rem ≤S dec At that moment, the PLC control system immediately issues a uniform deceleration command to ensure that the aluminum strip can come to a smooth stop before reaching the disc shear. S9, Precise End-of-Line Stop Control: When the PLC control system detects S... rem When the distance is ≤0.5m, an ultra-low speed command is forcibly sent to the frequency converter. The aluminum strip smoothly decreases to this speed within 2~3 seconds as it passes the ramp of the frequency converter and slowly advances. The PLC control system monitors the remaining distance in real time through the encoder. When S is detected... rem When the value is ≤ΔS1, where ΔS1 is the pre-stop compensation value, ranging from 0 to 0.8 mm, the PLC control system immediately cuts off the inverter enable signal and activates the pinch roller brake, and the aluminum strip is immediately locked. The positioning error can be controlled within ±0.2 mm.

2. The method for pre-positioning and speed control of the aluminum strip stitching head according to claim 1, characterized in that: Two sets of photoelectric detection devices are respectively installed on the inner side of the blade head on the operating side and the transmission side of the crescent scissors. The photoelectric detection device includes a photoelectric transmitter and a photoelectric receiver.

3. The method for pre-positioning and speed control of the aluminum strip stitching head according to claim 1, characterized in that: The displacement sensor is installed on the slide of the crescent-shaped scissor head.

4. The method for pre-positioning and speed control of the aluminum strip stitching head according to claim 1, characterized in that: There are two laser rangefinders A, which are installed on the inside of the blade head on the operating side and the transmission side of the crescent shear, respectively; there is one laser rangefinder B, which is installed on the frame at the entrance of the disc shear.

5. The method for pre-positioning and speed control of the aluminum strip stitching head according to claim 1, characterized in that: In steps S3 and S7, the laser rangefinder detects the seam head as follows: The laser rangefinder collects the distance value X between itself and the surface of the aluminum strip. When the laser rangefinder detects the change in distance value ΔX > W1 + W2 three times in a row within 3 seconds, it indicates that the seam head has been detected.

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