C-type dropless flip conveying method and control system for a multi-lane flexible zipper

Abstract

The application discloses a C-shaped non-drop overturning conveying method and a control system of a multi-channel flexible zipper, and belongs to the technical field of automatic detection of flexible belt-shaped workpieces. The method comprises the following steps: making N zippers that have completed front face detection enter a clamping channel formed by an upper flexible clamping belt and a lower conveying supporting belt in an attitude with the front faces upward; driving the upper and lower belts to apply clamping force on the zippers; making the upper and lower belts with the zippers clamped thereon run synchronously along a C-shaped path, and the zippers gradually complete 180-degree overturning with the change of curvature under the continuous clamping; keeping the lateral positions and channel numbers of the channels unchanged through channel mapping during the overturning process; and releasing the zippers to a back face detection belt after the overturning is completed, and keeping the channel numbers consistent. The application realizes non-drop overturning in the continuous conveying of the multi-channel flexible zippers, and the overturning process is free of falling, twisting and channel stringing, front and back face detection data can be accurately bound according to the channels, and the application is suitable for a zipper automatic detection line.

Description

Technical Field

[0001] This invention relates to the field of automated inspection and conveying technology for flexible strip workpieces, specifically to a C-type drop-free flipping conveying method and control system for multi-channel flexible zipper inspection lines. Background Technology

[0002] Zippers are widely used connectors in industries such as apparel, bags, and home textiles, making quality inspection a crucial step in the production process. In automated visual inspection lines, zippers typically require image acquisition and defect detection on both the front and back sides. Existing technologies primarily employ two approaches: one utilizes dual-sided cameras to achieve flip-free double-sided inspection, and the other employs mechanical flipping to physically flip the zipper between front and back inspections.

[0003] Based on a comparative analysis with existing technologies, the findings are summarized below.

[0004] Regarding zipper visual inspection and partial fixation, CN207081666U discloses a machine vision-based zipper inspection device, including a feeding unit, a vision unit, a cutting unit, a discharging unit, and a zipper clamp. The vision unit can arrange cameras on both sides of the zipper clamp to achieve image acquisition and inspection of the front and back sides of the zipper. This solution focuses on achieving double-sided inspection without flipping through cameras on both sides. It does not disclose how to continuously mechanically flip the zipper after front-side inspection to the back-side inspection state when multiple zippers are conveyed in parallel, nor does it disclose methods to prevent the zipper from falling freely, twisting, or going off track during the flipping process. CN206057200U discloses a zipper visual inspection machine and its zipper top stop fixing device, which limits the zipper near the top stop through clamps, chain-splitting components, and bosses. It belongs to the partial fixation and chain-guiding structure and does not involve a method for controlling the 180° flipping of the entire or multiple parallel zippers. CN114384087A discloses a vision-based zipper defect detection device, including a conveying device, a cutting device, a vision system, and a control system. The vision system can be configured with multiple cameras to acquire images of the front and back sides of the fabric tape, the chain teeth, and the end. This solution focuses on a multi-camera detection layout and does not disclose a C-type flipping control method for continuously flipping a multi-channel flexible zipper from the front detection conveying surface to the back detection conveying surface.

[0005] Regarding clamping, flipping, and conveying, CN103569644A discloses a tire flipping device, including a frame, a flipping mechanism, and a clamping and conveying mechanism. This device can transport a tire to the center, clamp it, and achieve a 180° flip. This solution is designed for large, rigid, ring-shaped products such as tires. It is a single-piece material clamping and then flipping station, with a control flow of stop → clamp → rotate → release. It is not suitable for scenarios where multiple flexible, slender zippers are conveyed and flipped simultaneously in a continuous inspection line. CN108482944B discloses a double-roller turning conveyor. The double-roller structure causes the belt conveyor path to turn at bends. This solution mainly addresses the problem of turning the conveying route for ordinary materials, rather than flipping flexible strip-shaped workpieces from face-up to back-up. It also does not disclose a control method for simultaneously clamping flexible zippers on a C-shaped curved path with upper and lower belts to achieve a 180° drop-free flip. CN203558517U discloses a tire flipping device, which is also a single-piece material clamping and flipping station. The flipping process involves a cycle of stopping, clamping, rotating, and releasing, which is not suitable for stable and continuous detection of multi-channel slender flexible zippers.

[0006] In summary, existing technologies have disclosed solutions such as zipper visual inspection, zipper partial limiting, ordinary turning conveyor, and large-item clamping and flipping. However, a C-type drop-free flipping conveyor control method and system specifically designed for multi-channel flexible zipper inspection lines has not yet been found. This system can continuously complete a 180° flip between the front and back inspection belts while maintaining the corresponding relationship between each channel. Summary of the Invention

[0007] This invention aims to solve the following core technical problems: First, existing flipping solutions are not suitable for continuous conveying of flexible, slender zippers—the large-item clamping and flipping mechanism adopts a stop-clamp-rotate-release cycle mode, which cannot achieve flipping in continuous conveying; Second, flexible zippers are at risk of falling, twisting, arching, and channel misalignment during flipping—if free flipping, air-blowing flipping, or mechanical flipping methods are used, the zipper landing point is uncertain, the posture is chaotic, and the correspondence between adjacent channels is lost; Third, multi-channel detection requires that the channel numbers between the front detection strip and the back detection strip be consistent for data binding and traceability, and existing flipping control methods lack corresponding channel mapping and maintenance mechanisms.

[0008] To solve the above technical problem, the present invention provides a C-type drop-free flipping conveying method for multi-channel flexible zippers, comprising: making N zippers that have completed front-side detection enter a clamping channel formed by an upper flexible clamping belt and a lower conveying support belt in a front-up posture, wherein N is an integer greater than or equal to 1; driving the upper flexible clamping belt and the lower conveying support belt to close, applying a clamping force to the effective support area of the zipper fabric belt, so that the zipper is constrained between the upper and lower double belts, and during the whole process from the zipper entering the clamping channel to being released to the back-side detection belt, the zipper is always supported by the upper flexible clamping belt or the lower conveying support belt, and there is no unconstrained free movement section; making the upper and lower double belts clamping the zipper run synchronously along a preset C-shaped path, and the zipper completes 180° flipping gradually with the curvature change of the C-shaped path under the continuous clamping state; during the flipping process, the transverse position of the zipper in each channel is detected in real time by position detection devices respectively arranged at the inlet and outlet of the C-shaped path, and channel mapping control is performed based on the detection result, so that the transverse position and channel number of each zipper from the 1st channel to the Nth channel remain unchanged when running along the C-shaped path; after flipping is completed, the zipper is released to the back-side detection belt through the overlapping handover area between the upper and lower double belts at the outlet and the back-side detection belt, so that the zipper maintains the back-up posture without twisting or sudden position change during the release process, and the channel numbers before and after flipping remain consistent.

[0009] Further, the equivalent radius R of the C-shaped path satisfies R ≥ R_min, wherein R_min is the minimum allowable flipping radius without damaging the zipper, and the value range of R is 160mm to 250mm.

[0010] Further, the linear velocity v_u of the upper flexible clamping belt and the linear velocity v_l of the lower conveying support belt satisfy the speed synchronization condition: |v_u - v_l| / v_l ≤ ε_v, wherein v_l>0, ε_v is the allowable speed difference ratio between the upper and lower belts, and ε_v is not more than 5%.

[0011] Further, the equivalent clamping force Fc of a single channel satisfies F_min ≤ Fc ≤ F_max; when Fc<F_min, an insufficient clamping force alarm is triggered and the clamping pressure is automatically increased; when Fc>F_max, an excessive clamping force alarm is triggered and the clamping pressure is automatically reduced.

[0012] Further, the value range of N is 1 to 8; the channel center distance P satisfies P ≥ W_max + Δ_c, wherein W_max is the maximum effective width of zippers of the same batch, Δ_c is the channel safety gap, and the value range of Δ_c is 2mm to 20mm.

[0013] Further, before the zipper enters the clamping passage, the method further comprises: controlling the postures of the front end and the tail end of the zipper through inlet transition support, so as to prevent the zipper from sagging, curling or lateral offset before entering the clamping area.

[0014] The present invention further provides a C-type zero-drop overturning control system for multi-channel flexible zippers, comprising: a front detection interface module, configured to receive N zippers after a front detection belt completes front image acquisition, and transmit in-position signals of zippers in each channel and channel number information to the overturning control system; a clamping force control module, configured to control the clamping force between an upper flexible clamping belt and a lower conveying support belt, so that the zipper is constrained between the upper belt and the lower belt; an overturning path control module, configured to control the upper belt and the lower belt clamping the zipper to synchronously operate along a preset C-type path, so that the zipper gradually completes 180° overturning along with the curvature change of the C-type path in a continuous clamping state; a channel mapping maintaining module, comprising position detection devices arranged at an inlet and an outlet of the C-type path, configured to detect the lateral position of the zipper in each channel in real time during the overturning process and keep the corresponding relationship of channel numbers of the N zippers unchanged, so that the zipper at the i-th channel on the front detection belt still corresponds to the i-th channel on a back detection belt after C-type overturning, wherein i=1, 2, …, N; and an outlet posture control module, configured to control the release of the overturned zipper to the back detection belt, so that the zipper keeps the back-up posture and does not twist or have sudden position change during the release process.

[0015] Further, the clamping force control module comprises a pressure setting unit, a pressure detection unit and a pressure adjusting unit; the pressure adjusting unit adopts at least one mode selected from spring force adjustment, cylinder pressure adjustment, counterweight moment adjustment, slider position adjustment or lead screw displacement adjustment, so that the equivalent clamping force Fc of a single channel is kept within an adjustable range from F_min to F_max; when Fc<F_min, the clamping force control module triggers an insufficient clamping force alarm and automatically increases the clamping pressure; when Fc>F_max, the clamping force control module triggers an excessive clamping force alarm and automatically reduces the clamping pressure.

[0016] Further, in the overturning path control module, an equivalent radius R of the C-type path satisfies R ≥ R_min, and R_min is 160mm.

[0017] Further, the system further comprises a speed synchronization control module, configured to control the upper flexible clamping belt and the lower conveying support belt to keep linear velocity synchronization, so that a speed difference ratio ε_v is not more than 5%; the speed synchronization control module is implemented by at least one mode selected from coaxial transmission control, synchronous belt linkage control, gear set linkage control, servo motor electronic gear ratio control or encoder feedback closed-loop control.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) Continuous flipping, no free fall: The zipper is flipped 180° along the C-shaped path under the constraint by the upper and lower double belt clamping control method, avoiding the uncertainty of the landing point, twisting, arching and secondary alignment difficulties caused by free flipping.

[0019] (2) Multi-channel parallel and channel mapping maintenance: The horizontal position of each channel zipper is detected in real time by the position detection device and the channel mapping control is performed based on the detection results. It is suitable for parallel detection of multiple flexible zippers. It can keep the channel number and horizontal correspondence unchanged before and after flipping, which is convenient for binding of front and back images, defect tracing and subsequent removal.

[0020] (3) Large radius path protection: By controlling the path radius of the flipping path, the equivalent radius R of the C-type path is controlled to be above 160mm, which effectively reduces the bending stress of the zipper during the flipping process and protects the chain teeth, fabric tape, zipper pull and MARK mark.

[0021] (4) Parameter Adaptation: The clamping force and the speed of the upper and lower belts can be adjusted by control methods to adapt to zippers of different lengths, widths, thicknesses and local protrusions without the need to replace mechanical parts.

[0022] (5) Continuous cycle and strong channel retention capability: Compared with the robot suction cup flipping one by one, air knife blowing, or existing roller secondary alignment scheme, the control method of the present invention can realize continuous cycle flipping without stopping and waiting, with strong channel retention capability and low subsequent alignment requirements.

[0023] (6) Modular and integrable: The control system of the present invention serves as a functional module between the front detection strip and the back detection strip, and can be integrated and deployed without changing the upstream and downstream detection equipment. Attached Figure Description

[0024] Figure 1 This is a flowchart of the overall process of a multi-channel flexible zipper C-type flip-over conveyor system.

[0025] Figure 2 This is a functional module architecture diagram of the flip control system.

[0026] Figure 3 This is a flowchart of the clamping force control logic.

[0027] Figure 4 This is a block diagram for speed synchronization control.

[0028] The meanings of the markings in the attached diagram are as follows: 1—Upper flexible clamping belt; 2—Lower conveyor support belt; 3—Clamping force control module; 4—Tilting path control module; 5—Speed ​​synchronization control module; 6—Channel mapping and holding module; 7—Exit posture control module; 8—Front-side detection interface module; 9—System integration interface module; 10—Pressure setting unit; 11—Pressure detection unit; 12—Pressure adjustment unit; 13—Tilting control system. Detailed Implementation

[0029] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0030] In this invention, the effective support area of ​​the zipper tape refers to the flat area on the zipper tape other than the protruding areas of the zipper head and zipper teeth, which can be evenly contacted and clamped by the upper flexible clamping belt and the lower conveyor support belt.

[0031] Example 1: C-type flip control of an 8-channel zipper detection line In this embodiment, see Figures 1 to 4 Eight zippers are conveyed side-by-side on the front inspection belt, N=8. Each zipper corresponds to an independent channel, and the center distance P of the channels is determined based on the maximum effective width W_max of the zippers in the same batch and the safety clearance Δ_c, where Δ_c is taken as 5mm to 10mm.

[0032] After the zipper passes the front detection, the front detection interface module 8 acquires the positioning signal and channel number information of each channel and transmits it to the flipping control system 13. The entrance transition control module ensures that the zipper enters the upper and lower double-belt clamping area in a stable, front-facing posture by controlling the guide surface inclination angle and support width of the entrance transition support. Throughout the entire process from entering the clamping channel to being released to the back detection belt, the zipper is always supported by the upper flexible clamping belt 1 or the lower conveyor support belt 2, with no unrestrained free movement segment, thus achieving "drop-free" flipping.

[0033] The clamping force control module 3 sets the single-channel equivalent clamping force Fc between F_min and F_max. F_min can be determined by the formula F_min = k1·(m·g + m·v). 2 / R) is determined, where m is the mass of a single zipper, v is the conveyor line speed, R is the equivalent radius of the C-shaped path, and k1 is the safety factor, ranging from 1.2 to 1.5; F_max is determined through a zipper tape compression test—an increasing pressure is applied to the zipper tape using a standard pressure head, and F_max is defined as 60% to 80% of the pressure value at which the tape exhibits irreversible deformation. In this embodiment, Fc ranges from 0.5N to 2N. The pressure detection unit 11 monitors the clamping force in real time, and if it exceeds the preset range, it triggers the pressure adjustment unit 12 for automatic correction.

[0034] After the zipper enters the upper and lower double-belt clamping area, the speed synchronization control module 5 uses encoder feedback closed-loop control to ensure that the difference ratio ε_v between the linear speed v_u of the upper flexible clamping belt 1 and the linear speed v_l of the lower conveyor support belt 2 is no greater than 3%, where v_l>0. The flipping path control module 4 drives the double belts to run along a C-shaped flipping path with an equivalent radius R=200mm. The C-shaped flipping path is formed by the bending of the upper and lower double belts guided by at least one guide wheel.

[0035] During the flipping process, the channel mapping and holding module 6 acquires the lateral position data of each channel zipper in real time through position detection devices located at the entrance and exit of the C-shaped flipping path. These position detection devices can be linear CCD sensor arrays or infrared through-beam position sensors, arranged laterally along the channel to locate the two edges of each zipper in real time. When the lateral offset of a zipper in a certain channel exceeds 30% of the channel safety gap Δ_c, the channel mapping and holding module 6 determines it as a channel deviation and triggers a lateral limiting guide wheel or adjustable partition located at the apex of the C-shaped flipping path to limit the lateral movement range of the zipper, ensuring that the channel indices of the zippers in channels 1 to 8 are always consistent at the entrance, apex, and exit of the C-shaped flipping path. The specific implementation of channel mapping control is not limited to the aforementioned sensor types and correction mechanisms; for example, a machine vision-based edge tracking method can also be used, where an industrial camera captures images of each channel at the entrance and exit of the C-shaped path, and the zipper edge positions are extracted through image processing for channel mapping.

[0036] After the flipping is complete, the exit posture control module 7 releases the zipper to the back detection belt with its back facing upwards through the overlapping area between the upper and lower double belts at the exit and the back detection belt. During the release process, the zipper maintains its back-facing upwards posture without twisting or abrupt position changes. After the back detection belt receives the zipper, the system integration interface module 9 binds the channel number with the front detection data and the back detection data.

[0037] Expected results: 8 zippers will complete a 180° rotation in continuous conveying mode. The channel numbers will be consistent before and after the rotation. There will be no zipper slippage, detachment or twisting. There will be no obvious indentations on the surface of the fabric and zipper teeth.

[0038] Example 2: Adaptive adjustment of clamping force for zippers of different thicknesses This embodiment differs from Embodiment 1 in that zippers of different thickness specifications need to be alternately processed on the same detection line, such as thin nylon zippers and thick metal zippers.

[0039] In the step of confirming and adjusting the clamping parameters, the clamping force control module 3 automatically calls the corresponding F_min and F_max thresholds according to the preset parameters of the current batch of zippers, including the tape thickness, the material of the teeth and the position of the slider. When switching from a thin zipper to a thick zipper, the clamping force control module 3 automatically increases Fc to a range suitable for thick zippers; otherwise, it automatically decreases Fc.

[0040] Meanwhile, when the slider passes through the clamping area, if the pressure detection unit 11 detects that the local pressure peak exceeds F_max, the clamping force control module 3 triggers an elastic adaptation mechanism, adopting cylinder buffering or spring yielding to avoid damage to the slider area, and automatically restores the normal clamping force after the slider passes. When Fc<F_min, the clamping force control module 3 triggers an insufficient clamping force alarm and automatically increases the clamping pressure; when Fc>F_max, it triggers an excessive clamping force alarm and automatically reduces the clamping pressure, forming a complete force control closed loop.

[0041] Example 3: Equivalent implementation of C-shaped path This embodiment presents various equivalent implementations of the turning path control module 4.

[0042] Implementation mode 1: Single large-radius guide wheel mode. The upper and lower double tapes are wound around a large-radius guide wheel with an equivalent radius R=200mm to form a C-shaped turning path.

[0043] Implementation mode 2: Combination of multiple small guide wheels. 6 to 12 small-radius guide wheels are arranged along the C-shaped arc, and the outer envelope of each guide wheel forms an arc path with an equivalent radius R≥160mm.

[0044] Implementation mode 3: Arc-shaped support plate mode. The upper and lower double tapes run along the curved surface of an arc-shaped support plate, the curvature radius R of the support plate is 160mm to 250mm, and rolling or sliding contact is formed between the double tapes and the plate surface.

[0045] Implementation mode 4: Semicircular guide rail mode. A semicircular guide rail is used as the running track for the double tapes, and the radius R of the guide rail is 180mm.

[0046] Implementation mode 5: Combination of flexible guide belts. The upper and lower double tapes are linked with the main drive system through flexible guide belts, and the guide belts are arranged along a preset arc path to form an equivalent C-shaped path.

[0047] The common feature of the above methods is that the upper and lower belts remain clamped on the C-shaped flipping path, and the zipper gradually completes a 180° flip during continuous conveying; the functions of the channel mapping and holding module 6 and the speed synchronization control module 5 are independent of the specific mechanical implementation of the path. The value of the flipping radius R can be flexibly selected according to the zipper specifications: for thin nylon zippers, R can be 160mm to save equipment space without causing damage; for thick metal zippers or zippers with large sliders, R can be 200mm to 250mm to further reduce bending stress.

[0048] Example 4: Single-channel independent control mode In this embodiment, the upper and lower belts adopt a narrow belt form with each channel independently set, that is, N upper clamping belts and N lower support belts, and each channel is independently configured with a pressure adjustment unit 12 and a speed synchronization unit.

[0049] The channel mapping and holding module 6 independently tracks the position of each channel. When a channel experiences zipper misalignment or insufficient clamping force, that channel can be adjusted individually without affecting the normal operation of other channels. This method is particularly suitable for scenarios where the zipper specifications of each channel are inconsistent or require individual adjustment.

[0050] Variation Example The preferred embodiments of the present invention have been described above. Those skilled in the art can make several modifications and improvements without departing from the concept of the present invention.

[0051] In terms of structural equivalent replacement, the position detection device in the channel mapping and holding module 6 can be any one or more combinations of a linear CCD sensor array, an infrared through-beam position sensor, a machine vision-based edge tracking system, or encoder indirect position estimation; the upper flexible clamping belt 1 can be replaced by an elastic belt, a synchronous belt with an elastic layer, or a combination of segmented narrow belts; the lower conveyor support belt 2 can be replaced by a conveyor belt, a synchronous belt, or a chain conveyor belt.

[0052] Regarding parameter range variations, the number of channels N can be adjusted from 1 to 8 according to the requirements of the detection line; the equivalent radius R of the C-type flip path can be adjusted from 160mm to 250mm according to the zipper specifications and spatial layout, where R=160mm is suitable for thin zippers or compact layout scenarios, and R=250mm is suitable for thick zippers or scenarios sensitive to bending stress; the speed difference ratio ε_v can be set from 1% to 5%, and the higher the detection cycle requirement, the lower the value of ε_v, while satisfying v_l>0.

[0053] Regarding the transformation of connection relationships, the speed synchronization control module 5 can adopt any one or more combinations of coaxial transmission control, synchronous belt linkage control, gear set linkage control, servo motor electronic gear ratio control, or encoder feedback closed-loop control.

[0054] The specific embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A C-shaped drop-free flipping conveying method for multi-channel flexible zippers, characterized in that, include: N zippers that have completed the front-side inspection are made to enter the clamping channel formed by the upper flexible clamping belt and the lower conveyor support belt with their front faces facing up, where N is an integer greater than or equal to 1; The upper flexible clamping belt and the lower conveyor support belt are driven to close, applying clamping force to the effective support area of ​​the zipper's fabric, thus constraining the zipper between the upper and lower belts. Throughout the entire process from entering the clamping channel to being released to the back detection belt, the zipper is always supported by the upper flexible clamping belt or the lower conveyor support belt, and there is no unrestrained free movement segment. The upper and lower straps holding the zipper move synchronously along a preset C-shaped path. Under continuous clamping, the zipper gradually completes a 180° rotation as the curvature of the C-shaped path changes. During the flipping process, the lateral position of the zipper in each channel is detected in real time by the position detection devices set at the entrance and exit of the C-shaped path respectively, and the channel mapping control is performed based on the detection results to keep the lateral position and channel number of each zipper from the first channel to the Nth channel unchanged when running along the C-shaped path. After the flip is completed, the zipper is released to the back detection belt through the overlapping area between the upper and lower double belts at the exit and the back detection belt. This ensures that the zipper remains in a back-facing position during release without twisting or sudden changes in position, and the channel number remains consistent before and after the flip.

2. The C-shaped drop-free flipping conveying method for multi-channel flexible zippers according to claim 1, characterized in that, The equivalent radius R of the C-shaped path satisfies R ≥ R_min, where R_min is the minimum allowable turning radius without damaging the zipper, and the value of R ranges from 160mm to 250mm.

3. The C-shaped drop-free flipping conveying method for multi-channel flexible zippers according to claim 1, characterized in that, The linear velocity v_u of the upper flexible clamping belt and the linear velocity v_l of the lower conveying support belt satisfy the speed synchronization condition: |v_u - v_l| / v_l ≤ ε_v, where v_l > 0, ε_v is the allowable speed difference ratio between the upper and lower belts, and ε_v is not greater than 5%.

4. The C-shaped drop-free flipping conveying method for multi-channel flexible zippers according to claim 1, characterized in that, The single-channel equivalent clamping force Fc satisfies F_min ≤ Fc ≤ F_max; when Fc < F_min, an insufficient clamping force alarm is triggered and the clamping pressure is automatically increased; when Fc > F_max, an excessive clamping force alarm is triggered and the clamping pressure is automatically reduced.

5. The C-shaped drop-free flipping conveying method for multi-channel flexible zippers according to claim 1, characterized in that, The value of N ranges from 1 to 8; the center distance P of the channel satisfies P ≥ W_max + Δ_c, where W_max is the maximum effective width of the zippers in the same batch, Δ_c is the safety gap of the channel, and the value of Δ_c ranges from 2mm to 20mm.

6. The C-shaped drop-free flipping conveying method for multi-channel flexible zippers according to claim 1, characterized in that, Before the zipper enters the clamping channel, the method further includes controlling the posture of the front and rear ends of the zipper through an inlet transition support to prevent the zipper from sagging, curling, or shifting laterally before entering the clamping area.

7. A C-type drop-free flipping control system for a multi-channel flexible zipper, characterized in that, include: The front detection interface module is used to receive the N zippers after the front detection belt has completed the front image acquisition, and transmit the positioning signal and channel number information of each channel zipper to the flip control system. The clamping force control module is used to control the clamping force between the upper flexible clamping belt and the lower conveyor support belt, so that the zipper is constrained between the upper and lower belts; The flip path control module is used to control the upper and lower double straps holding the zipper to run synchronously along a preset C-shaped path, so that the zipper gradually completes a 180° flip as the curvature of the C-shaped path changes under continuous clamping. The channel mapping and holding module includes a position detection device set at the entrance and exit of the C-shaped path. It is used to detect the lateral position of the zipper in each channel in real time during the flipping process and keep the channel number correspondence of the N zippers unchanged, so that the zipper of the i-th channel on the front detection strip still corresponds to the i-th channel on the back detection strip after the C-shaped flipping, i=1, 2, …, N; The exit posture control module is used to control the release of the zipper toward the back detection belt after the flipping is completed, so that the zipper maintains the back facing up posture during the release process and does not twist or change position abruptly.

8. The C-type drop-free flipping control system for multi-channel flexible zippers according to claim 7, characterized in that, The clamping force control module includes a pressure setting unit, a pressure detection unit, and a pressure adjustment unit. The pressure adjustment unit uses at least one of the following methods: spring force adjustment, cylinder pressure adjustment, counterweight torque adjustment, slider position adjustment, or lead screw displacement adjustment, to keep the single-channel equivalent clamping force Fc within the adjustable range of F_min to F_max. When Fc < F_min, the clamping force control module triggers an insufficient clamping force alarm and automatically increases the clamping pressure. When Fc > F_max, the clamping force control module triggers an excessive clamping force alarm and automatically decreases the clamping pressure.

9. The C-type drop-free flipping control system for multi-channel flexible zippers according to claim 7, characterized in that, In the flipping path control module, the equivalent radius R of the C-shaped path satisfies R ≥ R_min, where R_min is 160mm.

10. The C-type drop-free flipping control system for multi-channel flexible zippers according to claim 7, characterized in that, It also includes a speed synchronization control module, which controls the upper flexible clamping belt and the lower conveyor support belt to maintain synchronous linear speed, so that the speed difference ratio ε_v is not greater than 5%; the speed synchronization control module is implemented by at least one of the following methods: coaxial transmission control, synchronous belt linkage control, gear set linkage control, servo motor electronic gear ratio control or encoder feedback closed-loop control.

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