Flat-bed machine curved panel variable diameter opposite side seaming apparatus and method

Abstract

This invention discloses a device and method for sewing curved sheets with varying diameters on a flat knitting machine, belonging to the field of textile machinery technology. The device includes a curling mechanism and a sewing mechanism; the curling mechanism includes a variable-diameter cylindrical device and a matching holding mechanism. The variable-diameter cylindrical device includes an inner cylinder and an outer cylinder, which expand or contract synchronously via corresponding telescopic connecting rods and a central spindle. The holding mechanism is controlled by an electromagnet, achieving precise holding of the curved sheet by switching the magnetic pole direction. Through the curling and sewing mechanisms, this device expands the fan-shaped curved sheet from a two-dimensional to a three-dimensional structure during rotation, while simultaneously achieving automatic edge sewing of the curved sheet. The inner cylinder can move axially relative to the outer cylinder, allowing the sewn curved sheet to automatically detach from the outer cylinder. This invention simultaneously achieves gripping, curling, expansion, alignment, and demolding, and is suitable for sewing curved sheets with varying diameters on both sides.

Description

Technical Field

[0001] This invention relates to the field of textile machinery technology, and in particular to a device and method for stitching curved sheets of a flat knitting machine with varying diameters at the edges. Background Technology

[0002] Computerized flat knitting machines can weave fan-shaped two-dimensional curved sheets with a certain curvature. In traditional processing techniques, the stitching of these fan-shaped curved sheets presents the following problems: I. Efficiency and Quality Issues of Manual Sewing Manual sewing, or sewing with the help of manually operated sewing machines or sewing pads, is cumbersome, involves repeated adjustments to the position of the sheet, is inefficient and labor-intensive, and is difficult to meet the needs of continuous production. On the other hand, the sewing quality is highly dependent on the operator's experience, and there are significant differences in edge accuracy and sewing effect between different batches or different operators, resulting in poor consistency in forming and affecting the structural stability and appearance quality of the finished product.

[0003] II. Problems with the applicability of existing automatic sewing devices Existing technologies include automatic closing devices for sewing the toes of stockings on circular knitting machines. These devices can automatically align and sew the edges of tubular or near-tubular fabrics. However, their structure and working principle are mainly designed for cylindrical fabrics and cannot be directly applied to fan-shaped two-dimensional curved sheets produced after a computerized flat knitting machine. The geometry of fan-shaped sheets differs fundamentally from that of tubular fabrics, and existing devices lack the necessary gripping, diameter expansion, and edge alignment mechanisms, making them unable to meet the special forming requirements of fan-shaped sheets.

[0004] III. Controllable Deformation Problem of Surface Patches Transformed from Two-Dimensional to Three-Dimensional During the sewing process, the fan-shaped curved sheet needs to transform from a planar state to a three-dimensional circular structure, a process involving spatial deformation of the curved sheet. Current technology lacks a device capable of actively controlling the sheet deformation process, making it difficult to ensure the morphological stability of the sheet during unfolding, curling, and sewing. In existing technologies, the sheet is prone to localized warping, wrinkling, or uneven stretching during deformation, affecting the accuracy of subsequent edge sewing and the quality of the finished product.

[0005] IV. The problem of automatic edge alignment during the deformation process of curved surface sheets of different sizes During the transformation of a fan-shaped sheet from a two-dimensional plane to a three-dimensional solid, the precise alignment of the changed two edges is simultaneously achieved so that the sewing mechanism can complete the closure. Current technology lacks the ability to adaptively and automatically align the edges during the deformation process, adapting to different sizes and degrees of deformation of the curved sheet.

[0006] V. The problem of automatic demolding of the finished product after the curved surface sheets are sewn together. After the curved sheet is rolled, unfolded, and edge-sewn, the finished product fits tightly against the surface of the device. Currently, the rolling, unfolding, and demolding processes in existing devices are independent systems, often requiring additional demolding equipment, increasing system complexity, and making synchronous coordination and control of each system more difficult. How to achieve automatic demolding of the finished product using the device itself, thereby increasing system integration, still requires optimization.

[0007] In summary, existing manual sewing methods are inefficient and inconsistent, while existing automated devices cannot adapt to the special shape and deformation requirements of fan-shaped curved sheets. Furthermore, effective technical solutions are lacking in key aspects such as controllable deformation from two-dimensional to three-dimensional, automatic edge alignment, and automatic demolding. Therefore, there is an urgent need to develop a specialized device with a reasonable structure and integrated functions, capable of automatically grasping, controlling the deformation of, automatically aligning the edges, automatically sewing, and automatically demolding fan-shaped two-dimensional curved sheets. Summary of the Invention

[0008] This invention proposes a device and method for aligning and sewing curved sheets with varying diameters on a flat knitting machine, in order to solve the problems of efficiency and quality in manual sewing; the inapplicability of existing automatic sewing devices; the problem of controllable deformation of curved sheets from two-dimensional to three-dimensional; the problem of automatic alignment of curved sheets during deformation; and the problem of automatic demolding of finished products after sewing of curved sheets.

[0009] The core technical solution of this invention lies in: achieving synchronous expansion and contraction of the inner and outer cylinders through a variable diameter cylinder device, realizing controllable and gradual deformation of the curved sheet from a two-dimensional plane to a three-dimensional solid; utilizing an electromagnetic pressing mechanism to achieve precise control of the pressing force through magnetic pole switching, reducing damage to high-performance materials; and automatically pushing the sewn finished product out of the outer cylinder surface through axial movement of the inner cylinder, achieving automatic demolding; forming a complete automated closed loop from gripping, deformation, edge alignment, sewing to demolding.

[0010] The specific solution of the present invention is as follows: A device for stitching curved sheets with varying diameters on opposite sides of a flat knitting machine includes a curling mechanism and a stitching mechanism. The curling mechanism includes a rotatable variable diameter cylindrical device and a pressing mechanism that cooperates with the variable diameter cylindrical device. The variable diameter cylindrical device includes an inner cylindrical layer and an outer cylindrical layer, with the outer cylindrical layer sleeved on the outside of the inner cylindrical layer; the inner cylindrical layer and the outer cylindrical layer are each a truncated cone composed of several arc plates. The inner cylinder is mounted on the first central main shaft via an inner cylinder telescopic connecting rod, and the outer cylinder is mounted on the second central main shaft via an outer cylinder telescopic connecting rod. When the first central spindle and the second central spindle rotate synchronously, they drive the inner cylindrical telescopic connecting rod and the outer cylindrical telescopic connecting rod to expand or contract, causing the inner cylindrical and outer cylindrical to expand or contract with varying diameters. When the variable diameter cylindrical device rotates and expands, it drives the curved surface sheet to transform from a two-dimensional planar structure to a three-dimensional solid structure, and realizes the alignment of the edges to be sewn. Under the pressure of the holding mechanism, the edges to be sewn are sewn by the sewing mechanism.

[0011] Furthermore, the inner cylindrical telescopic connecting rod includes a first fixed block and a first slider. The first fixed block and the first slider are connected by a number of multi-stage connecting rods, and one of the multi-stage connecting rods is fixedly connected to one of the arc plates of the inner cylindrical layer. The first central spindle includes at least a first lead screw section, the first slider is mounted on the first lead screw section, and the inner side of the first slider is provided with a thread that mates with the first lead screw section; When the first central spindle rotates, the first slider can reciprocate relative to the first fixed block, causing the inner cylindrical telescopic connecting rod to expand or contract.

[0012] Furthermore, the outer cylindrical telescopic connecting rod includes a second fixed block and a second slider. The second fixed block and the second slider are connected by several sets of multi-stage connecting rods. One set of the multi-stage connecting rods is fixedly connected to one of the arc plates of the outer cylindrical shell. The second central spindle includes at least a second lead screw section, the second slider is mounted on the second lead screw section, and the inner side of the second slider is provided with a thread that mates with the second lead screw section; When the second central spindle rotates, the second slider can reciprocate relative to the second fixed block, causing the outer cylindrical telescopic connecting rod to expand or contract.

[0013] Furthermore, the second central spindle has a cavity inside, and a groove is provided inside the cavity; the first central spindle has a protrusion that matches the groove, and the second central spindle is sleeved on the outside of the first central spindle. The groove and the protrusion cooperate to restrict their relative rotation and keep them rotating synchronously under the drive of the first motor.

[0014] Furthermore, the first central spindle includes at least a rack segment, which is meshed with the second motor through a gear transmission structure to convert the rotational motion of the second motor into linear motion of the first central spindle, so that the first central spindle can move axially relative to the second central spindle, thereby realizing the axial movement of the inner cylinder relative to the outer cylinder.

[0015] Furthermore, the pressing mechanism includes a connecting rod and a pressing block. One end of the connecting rod is connected to the pressing block, and the other end is connected to the first central spindle or the second central spindle, so that the pressing block can rotate synchronously with the outer cylinder under the drive of the connecting rod.

[0016] Furthermore, the linkage includes a first linkage and a second linkage sleeved together. The first linkage is connected to the second linkage through an elastic element, so that the first linkage can extend and retract relative to the second linkage.

[0017] Furthermore, a first electromagnet is provided inside the pressing block, and a second electromagnet or ordinary magnet is correspondingly provided on the outer cylinder; by controlling the direction of the magnetic poles of the first electromagnet, the pressing block can switch between an open state away from the outer cylinder and a pressing state close to the outer cylinder.

[0018] Furthermore, the pressing block includes a frame, and the frame has a sewing space inside. The frame is used to press the curved sheet, and the sewing mechanism performs sewing within the sewing space.

[0019] A sewing method for a variable diameter, edge-to-edge sewing device for curved sheets on a flat knitting machine, the method comprising: Step 1: Initially, adjust the variable diameter cylinder device to the contracted state to facilitate the gripping and introduction of the curved surface sheet; Step 2: By controlling the switching of the magnetic poles of the first electromagnet, the first sector edge of the curved sheet is fed into the gap between the pressing mechanism and the outer cylinder, so that the pressing mechanism presses and fixes the first sector edge. Step 3: The first motor rotates in the forward direction, driving the first central spindle and the second central spindle to rotate synchronously. The first lead screw segment and the second lead screw segment drive the first slider and the second slider to move towards the first fixed block and the second fixed block, respectively, so that the inner cylinder telescopic connecting rod and the outer cylinder telescopic connecting rod fold synchronously, pushing the inner cylinder and the outer cylinder to expand outward synchronously, and driving the curved surface sheet to gradually rotate and unfold from two dimensions to three dimensions on the surface of the outer cylinder. Step 4: Control the expansion dimension of the variable diameter cylinder device so that the second sector edge of the curved surface plate overlaps with the first sector edge after one rotation, thus achieving automatic edge alignment; Step 5: After the second sector edge and the first sector edge are aligned, the magnetic poles of the first electromagnet are switched by controlling the pressing mechanism to press the first sector edge and the second sector edge after alignment. Step Six: The sewing mechanism automatically sewn the first and second sector edges of the curved surface sheet, closing the two-dimensional sector-shaped planar curved surface sheet to form a three-dimensional structure; Step 7: The first motor rotates in the opposite direction, causing the first and second sliders to move away from the first and second fixed blocks, driving the inner and outer cylinders to shrink inward synchronously, and the variable diameter cylinder device returns to the shrunken state; then the second motor starts, and through gear and rack transmission, the first central spindle moves axially relative to the second central spindle, driving the inner cylinder to move axially relative to the outer cylinder, pushing the stitched curved sheet product out from the surface of the outer cylinder, completing the automatic demolding.

[0020] The present invention has the following technical effects: This invention employs a double-layer sleeve structure composed of an inner and outer cylinder. By synchronously expanding or contracting a variable-diameter cylinder device, it achieves active and precise control over the unfolding shape and speed of the curved sheet. The curved sheet is uniformly spread out on the outer surface of the outer cylinder, and the deformation process is smooth and controllable, improving problems such as local warping, wrinkles, or uneven stretching, and providing a good morphological basis for subsequent edge stitching.

[0021] The pressing mechanism of this invention can synchronously follow the expansion and contraction of the variable diameter cylindrical device. The electromagnetic pressing mechanism controls the pressing position, pressing time and pressing force, so that the first sector edge and the second sector edge of the curved sheet accurately overlap on the cylindrical surface, which improves the material damage caused by excessive pressing or the slippage caused by insufficient pressing.

[0022] A rack segment is installed on the first central spindle, which is driven by a second motor meshing with a gear to achieve axial movement of the inner cylinder relative to the outer cylinder. After sewing is completed, the axial movement of the inner cylinder smoothly pushes the finished product out of the surface of the outer cylinder, realizing automatic demolding of the finished product.

[0023] The invention has a simple overall structure and a reasonable layout of functional modules, which simultaneously realize multiple functions such as gripping, curling, spreading, alignment and demolding, and has a high degree of integration.

[0024] In summary, this invention effectively solves the key technical problems of existing curved sheet materials, such as the difficulty in controlling the deformation from two dimensions to three dimensions, the difficulty in automatic edge alignment, and the difficulty in automatic demolding, and realizes continuous, automated, and high-quality edge alignment and stitching of fan-shaped two-dimensional curved sheet materials. Attached Figure Description

[0025] Figure 1 This is a system diagram of the cross-sectional stitching device for curved sheet of the flat knitting machine according to the present invention; Figure 2 This is a schematic diagram of the assembly of the variable diameter cylindrical device in one embodiment of the present invention; Figure 3 This is a partial cross-sectional view of a variable diameter cylindrical device in one embodiment of the present invention; Figure 4 This is a side view of a variable diameter cylindrical device in one embodiment of the present invention; Figure 5 This is a schematic diagram of a first central spindle and a second central spindle in one embodiment of the present invention; Figure 6 This is a schematic diagram of the holding mechanism in one embodiment of the present invention; Figure 7 This is a photograph of the curved surface sheet before stitching in one embodiment of the present invention; Figure 8 This is a photograph of the actual product after the curved surface sheets are stitched together, according to one embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures: 1. Computerized flat knitting machine; 2. Tension guide roller; 3. Pressing guide roller; 4. Support frame; 5. Electrical box; 6. Waste yarn detection device; 7. Waste yarn cutting support frame; 8. Waste yarn cutting mechanism; 9. Curling mechanism; 10. Air pump; 11. Waste suction nozzle; 12. Sewing mechanism; 91. Pressing mechanism; 92. Variable diameter cylinder device; 93. Coiling mechanism support frame; 94. First motor; 95. Second motor; 911. First electromagnet; 912. First connecting rod; 913. Second connecting rod; 914. Elastic element; 921. Inner cylinder; 922. Outer cylinder; 923. Outer cylinder telescopic link; 924. Inner cylinder telescopic link; 925. First slider; 926. Second slider; 927. First central spindle; 928. Second central spindle. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] In this specification, identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions towards or away from a specific component, respectively. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this specification, "multiple" means two or more.

[0029] Example 1 This invention provides a device for stitching curved sheet with variable diameter on opposite sides of a flat knitting machine. Figure 1 The overall system structure of the device of this invention is demonstrated. The process connection of the system includes front-end feeding, waste yarn treatment, and subsequent crimping and sewing. Specifically, the computer flat knitting machine 1 weaves a curved sheet. In this embodiment, a two-dimensional fan-shaped curved sheet is used as an example. The curved sheet has a V-shaped opening, and the two sides of the V-shaped opening are the first and second fan-shaped sides to be sewn. The device is powered by the electrical box 5. The sheet first passes through the tension guide roller 2 and the pressure guide roller 3, and is kept under stable tension under the action of the guide rollers. Then it is conveyed to the waste yarn detection device 6 through the support frame 4. The waste yarn detection device 6 is used to detect the waste yarn connection section between adjacent sheets. When waste yarn is detected, the waste yarn cutting mechanism 8 is activated to cut the waste yarn. The waste yarn cutting mechanism 8 is installed on the waste yarn cutting support frame 7. At the same time, the waste suction nozzle 11 sucks away the waste yarn under the action of the air pump 10, so that only the curved sheet enters the subsequent crimping mechanism 9, and finally it is sewn by the sewing mechanism 12.

[0030] like Figure 2 As shown, the curling mechanism 9 includes a variable diameter cylindrical device 92 mounted on a curling mechanism support frame 93. The variable diameter cylindrical device 92 is equipped with a pressing mechanism 91. The pressing mechanism 91 rotates synchronously with the variable diameter cylindrical device 92. The first motor 94 provides power to the curling mechanism 9.

[0031] Specifically, by Figure 3 , Figure 4 As shown, the variable diameter cylindrical device 92 includes an inner cylindrical layer 921 and an outer cylindrical layer 922. The inner cylindrical layer 921 is composed of several arc-shaped pieces forming a truncated cone. The outer cylindrical layer 922 has the same structure as the inner cylindrical layer 921, also consisting of several arc-shaped pieces forming a truncated cone. The difference is that the outer cylindrical layer 922 is larger than the inner cylindrical layer 921, so that it can be fitted onto the outside of the inner cylindrical layer 921.

[0032] like Figure 5 As shown, the inner cylinder 921 is mounted on the first central spindle 927 via the inner cylinder telescopic connecting rod 924. The inner cylinder telescopic connecting rod 924 includes a first fixed block and a first slider 925. The first fixed block and the first slider 925 are connected by several sets of multi-stage connecting rods. Each set of multi-stage connecting rods is provided with a connecting plate. A circular arc piece of the inner cylinder 921 is fixedly connected to a set of connecting plates.

[0033] The first central spindle 927 includes at least a first lead screw section, and a first slider 925 is mounted on the first lead screw section. The inner side of the first slider 925 is threaded. When the first central spindle 927 rotates clockwise or counterclockwise, the first slider 925 can reciprocate along the first central spindle 927. When the first slider 925 moves closer to the first fixed block, the multi-stage connecting rod folds and pushes each arcuate piece of the inner cylinder 921 to expand outward; when the first slider 925 moves away from the first fixed block, the multi-stage connecting rod tends to be straightened, causing each arcuate piece of the inner cylinder 921 to contract inward.

[0034] The outer cylinder 922 is mounted on the second central spindle 928 via the outer cylinder telescopic connecting rod 923. The outer cylinder telescopic connecting rod 923 includes a second fixed block and a second slider 926. The second fixed block and the second slider 926 are connected by several sets of multi-stage connecting rods. Each set of multi-stage connecting rods is provided with a connecting plate. A circular arc piece of the outer cylinder 922 is fixedly connected to a set of connecting plates.

[0035] The second central spindle 928 includes at least a second lead screw section, and a second slider 926 is mounted on the second lead screw section. The inner side of the second slider 926 is threaded. When the second central spindle 928 rotates clockwise or counterclockwise, the second slider 926 can reciprocate along the second central spindle 928. When the second slider 926 moves closer to the second fixed block, the multi-stage connecting rod folds and pushes each arcuate piece of the outer cylinder 922 to expand outward; when the second slider 926 moves away from the second fixed block, the multi-stage connecting rod tends to be straightened, causing each arcuate piece of the outer cylinder 922 to contract inward. Thus, the gripping variable diameter cylinder device 92 can maintain a small diameter when the sheet enters the device, facilitating gripping and introduction, and can gradually increase the diameter during rotation, causing the curved sheet to be spread along the outer surface of the outer cylinder 922.

[0036] The second central spindle 928 has an internal cavity with a groove inside. The first central spindle 927 has a protrusion that matches the groove. The second central spindle 928 can be inserted into the cavity and connected to the first central spindle 927. The matching of the groove and the protrusion restricts their relative rotation, allowing them to rotate synchronously. The first central spindle 927 includes at least a rack segment, which is connected to the second motor 95 through a gear transmission structure. This converts the rotational motion of the second motor 95 into linear movement of the first central spindle 927, allowing the first central spindle 927 to move relative to the second central spindle 928, thus realizing the axial movement of the inner cylinder 921 relative to the outer cylinder 922.

[0037] like Figure 6As shown, the pressing mechanism 91 includes a connecting rod, one end of which is connected to the pressing block, and the other end is connected to either the first central spindle 927 or the second central spindle 928, allowing the pressing block to rotate synchronously with the outer cylinder 922. The connecting rod includes a first connecting rod 912 and a second connecting rod 913 sleeved together. The first connecting rod 912 is connected to the second connecting rod 913 via an elastic element 914, allowing the first connecting rod 912 to extend and retract relative to the second connecting rod 913. When the variable diameter cylinder device 92 expands or contracts, the first connecting rod 912 stretches or compresses the elastic element 914, enabling the pressing mechanism 91 to synchronously follow the diameter change process.

[0038] The pressing block is positioned on the outside of the outer cylinder 922, with an arc-shaped inner side to allow it to fit snugly against the outer cylinder 922. The pressing block includes a frame for pressing the curved sheet, with a sewing space inside the frame. This allows for pressing of the curved sheet without affecting the sewing process.

[0039] The pressing block is equipped with a first electromagnet 911 inside, and a matching second electromagnet or ordinary magnet is installed on the outer cylinder 922. By changing the direction of the magnetic poles of the first electromagnet 911 through alternating current, the pressing block is switched between an open state away from the outer cylinder 922 and a clamping state close to the outer cylinder 922. When the magnetic poles repel each other, the magnetic force pushes the pressing block away from the outer cylinder 922, leaving a gap between them. At this time, the curved sheet can be sent between the pressing block and the outer cylinder 922. When the magnetic poles attract each other, the pressing block presses the curved sheet under the action of attraction.

[0040] Example 2 This invention provides a method for stitching curved sheet with variable diameter on opposite sides using a flat knitting machine: Figure 7 This is a photograph of a curved sheet woven by a flat knitting machine before sewing. The curved sheet is a two-dimensional planar structure. In the initial state, the variable diameter cylindrical device 92 is adjusted to a contracted state to facilitate the gripping and introduction of the curved sheet.

[0041] Curved sheet first sector edge pressing: The curved sheet is fed in, the first electromagnet 911 switches to the magnetic pole repulsion state, at which time the pressing block is far away from the outer cylinder 922, leaving a gap for the curved sheet to enter. The first sector edge of the curved sheet is sent into the gap between the pressing mechanism 91 and the outer cylinder 922. Then the first electromagnet 911 switches to the magnetic pole attraction state, at which time the pressing block is attracted to the surface of the outer cylinder 922, pressing the curved sheet on the surface of the outer cylinder 922.

[0042] Curved surface sheet rotation unfolding: The first motor 94 rotates in the forward direction, driving the first central spindle 927 and the second central spindle 928 to rotate synchronously. The first lead screw section rotates, driving the first slider 925 to move and approach the first fixed block. The second lead screw section rotates, driving the second slider 926 to move and approach the second fixed block. This causes the outer cylindrical telescopic connecting rod 923 and the inner cylindrical telescopic connecting rod 924 to fold synchronously, pushing the inner cylindrical 921 and the outer cylindrical 922 to rotate synchronously and expand outward, gradually increasing the diameter. At the same time, it drives the curved surface sheet to gradually rotate and unfold from two-dimensional to three-dimensional on the surface of the outer cylindrical 922.

[0043] Edge alignment of curved sheet to be sewn: Based on the size of the curved sheet, control the inner cylinder 921 and the outer cylinder 922 to rotate synchronously and expand their size, ensuring that when the variable diameter cylinder device 92 rotates one revolution, the second sector edge and the first sector edge of the curved sheet overlap, thus achieving automatic edge alignment.

[0044] Pressing the second sector edge of the curved sheet: After the variable diameter cylinder device 92 rotates one revolution, the first electromagnet 911 switches to a state of magnetic pole repulsion. At this time, the pressing block moves away from the outer cylinder 922, leaving space for the curved sheet to enter. After the second sector edge of the curved sheet overlaps with the first sector edge of the curved sheet, the first electromagnet 911 switches to a state of magnetic pole attraction. At this time, the pressing block is attracted to the surface of the outer cylinder 922, pressing the first and second sector edges after the opposite edges.

[0045] A first electromagnet 911 is used to achieve precise control of the holding mechanism 91 in terms of holding position and holding time. Adjusting the attraction force of the first electromagnet 911 can control the holding force, improving the situation where excessively tight holding can damage high-performance materials such as carbon fiber curved sheets, or where insufficient holding can cause the curved sheets to slip. The first and second fan-shaped edges to be sewn are held and positioned to keep the two sides stable during the sewing process, improving the problems of springback, slippage, or local lifting of the curved sheets.

[0046] Curved surface sheet edge stitching: After the edges of the curved surface sheet to be stitched are held together, the stitching mechanism 12 starts working to automatically stitch the two edges of the curved surface sheet together, such as... Figure 8 As shown, a two-dimensional fan-shaped planar curved surface sheet is closed to form a three-dimensional structure. This invention does not achieve edge alignment through simple pulling, but rather through a continuous process of diameter reduction gripping, rotation curling, and diameter expansion, enabling the curved surface sheet to stably unfold and automatically align its edges.

[0047] Demolding of the finished curved sheet: After the stitching is completed, the first motor 94 rotates in the opposite direction, the first slider 925 moves away from the first fixed block, the multi-stage connecting rod tends to be straightened, and drives each arc piece of the inner cylinder 921 to shrink inward; the second slider 926 moves away from the second fixed block, the multi-stage connecting rod tends to be straightened, and drives each arc piece of the outer cylinder 922 to shrink inward.

[0048] After the variable-diameter cylinder device 92 retracts to its initial state, the second motor 95 starts. Through gear engagement with the rack section of the first central spindle 927, the gear and rack transmission converts the rotational motion of the second motor 95 into linear movement of the first central spindle 927. This allows the first central spindle 927 to move relative to the second central spindle 928, thus enabling the inner cylinder 921 to move relative to the outer cylinder 922. As the inner cylinder 921 moves, it synchronously moves the stitched curved surface sheet, allowing the stitched curved surface sheet to be demolded from the surface of the outer cylinder 922.

[0049] After demolding is completed, the second motor 95 reverses and meshes with the rack segment of the first central spindle 927 through a gear transmission structure, causing the first central spindle 927 to move in the opposite direction and reset. At this time, the device returns to its initial state, waiting for the next curved sheet to enter, thus realizing the continuous automatic grasping, automatic curling, automatic expansion, and automatic edge alignment of the fan-shaped two-dimensional curved sheet, providing a reliable foundation for the subsequent automatic edge closure by the sewing mechanism 12.

[0050] In the embodiments disclosed in this application, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments disclosed in this invention according to the specific circumstances.

[0051] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A device for stitching curved sheets of a flat knitting machine with varying diameters along opposite sides, characterized in that, Includes a curling mechanism and a sewing mechanism. The curling mechanism includes a rotatable variable diameter cylindrical device and a pressing mechanism that cooperates with the variable diameter cylindrical device. The variable diameter cylindrical device includes an inner cylindrical layer and an outer cylindrical layer, with the outer cylindrical layer sleeved on the outside of the inner cylindrical layer; the inner cylindrical layer and the outer cylindrical layer are each a truncated cone composed of several arc plates. The inner cylinder is mounted on the first central main shaft via an inner cylinder telescopic connecting rod, and the outer cylinder is mounted on the second central main shaft via an outer cylinder telescopic connecting rod. When the first central spindle and the second central spindle rotate synchronously, they drive the inner cylindrical telescopic connecting rod and the outer cylindrical telescopic connecting rod to expand or contract, causing the inner cylindrical and outer cylindrical to expand or contract with varying diameters. When the variable diameter cylindrical device rotates and expands, it drives the curved surface sheet to transform from a two-dimensional planar structure to a three-dimensional solid structure, and realizes the alignment of the edges to be sewn. Under the pressure of the holding mechanism, the edges to be sewn are sewn by the sewing mechanism.

2. The flat knitting machine curved sheet variable diameter side-sewing device according to claim 1, characterized in that, The inner cylindrical telescopic connecting rod includes a first fixed block and a first slider. The first fixed block and the first slider are connected by several sets of multi-stage connecting rods. One set of the multi-stage connecting rods is fixedly connected to one of the arc plates of the inner cylindrical tube. The first central spindle includes at least a first lead screw section, the first slider is mounted on the first lead screw section, and the inner side of the first slider is provided with a thread that mates with the first lead screw section; When the first central spindle rotates, the first slider can reciprocate relative to the first fixed block, causing the inner cylindrical telescopic connecting rod to expand or contract.

3. The flat knitting machine curved sheet variable diameter side-to-side stitching device according to claim 1, characterized in that, The outer cylindrical telescopic connecting rod includes a second fixed block and a second slider. The second fixed block and the second slider are connected by several sets of multi-stage connecting rods. One set of the multi-stage connecting rods is fixedly connected to one of the arc plates of the outer cylindrical shell. The second central spindle includes at least a second lead screw section, the second slider is mounted on the second lead screw section, and the inner side of the second slider is provided with a thread that mates with the second lead screw section; When the second central spindle rotates, the second slider can reciprocate relative to the second fixed block, causing the outer cylindrical telescopic connecting rod to expand or contract.

4. The flat knitting machine curved sheet variable diameter edge-sewing device according to claim 1, characterized in that, The second central spindle has a cavity inside, and a groove is provided inside the cavity; the first central spindle has a protrusion that matches the groove, and the second central spindle is sleeved on the outside of the first central spindle. The groove and the protrusion cooperate to restrict their relative rotation and keep them rotating synchronously under the drive of the first motor.

5. The flat knitting machine curved sheet variable diameter edge-sewing device according to claim 1, characterized in that, The first central spindle includes at least a rack segment, which is meshed with the second motor through a gear transmission structure to convert the rotational motion of the second motor into linear motion of the first central spindle, so that the first central spindle can move axially relative to the second central spindle, thereby realizing the axial movement of the inner cylinder relative to the outer cylinder.

6. The flat knitting machine curved sheet variable diameter side-to-side stitching device according to claim 1, characterized in that, The pressing mechanism includes a connecting rod and a pressing block. One end of the connecting rod is connected to the pressing block, and the other end is connected to the first central spindle or the second central spindle, so that the pressing block can rotate synchronously with the outer cylinder under the drive of the connecting rod.

7. The flat knitting machine curved sheet variable diameter edge-sewing device according to claim 6, characterized in that, The linkage includes a first linkage and a second linkage sleeved together. The first linkage is connected to the second linkage through an elastic element, so that the first linkage can extend and retract relative to the second linkage.

8. The flat knitting machine curved sheet variable diameter edge-sewing device according to claim 6, characterized in that, The pressure block is equipped with a first electromagnet inside, and a second electromagnet or ordinary magnet is correspondingly provided on the outer cylinder; by controlling the direction of the magnetic poles of the first electromagnet, the pressure block can be switched between an open state away from the outer cylinder and a pressing state close to the outer cylinder.

9. The flat knitting machine curved sheet variable diameter side-to-side stitching device according to claim 6, characterized in that, The pressing block includes a frame with a sewing space inside. The frame is used to press the curved sheet, and the sewing mechanism performs sewing within the sewing space.

10. The sewing method of the flat knitting machine curved sheet variable diameter edge sewing device according to any one of claims 1-9, characterized in that, The method includes: Step 1: Initially, adjust the variable diameter cylinder device to the contracted state to facilitate the gripping and introduction of the curved surface sheet; Step 2: By controlling the switching of the magnetic poles of the first electromagnet, the first sector edge of the curved sheet is fed into the gap between the pressing mechanism and the outer cylinder, so that the pressing mechanism presses and fixes the first sector edge. Step 3: The first motor rotates in the forward direction, driving the first central spindle and the second central spindle to rotate synchronously. The first lead screw segment and the second lead screw segment drive the first slider and the second slider to move towards the first fixed block and the second fixed block, respectively, so that the inner cylinder telescopic connecting rod and the outer cylinder telescopic connecting rod fold synchronously, pushing the inner cylinder and the outer cylinder to expand outward synchronously, and driving the curved surface sheet to gradually rotate and unfold from two dimensions to three dimensions on the surface of the outer cylinder. Step 4: Control the expansion dimension of the variable diameter cylinder device so that the second sector edge of the curved surface plate overlaps with the first sector edge after one rotation, thus achieving automatic edge alignment; Step 5: After the second sector edge and the first sector edge are aligned, the magnetic poles of the first electromagnet are switched by controlling the pressing mechanism to press the first sector edge and the second sector edge after alignment. Step Six: The sewing mechanism automatically sewn the first and second sector edges of the curved surface sheet, closing the two-dimensional sector-shaped planar curved surface sheet to form a three-dimensional structure; Step 7: The first motor rotates in the opposite direction, causing the first and second sliders to move away from the first and second fixed blocks, driving the inner and outer cylinders to shrink inward synchronously, and the variable diameter cylinder device returns to the shrunken state; then the second motor starts, and through gear and rack transmission, the first central spindle moves axially relative to the second central spindle, driving the inner cylinder to move axially relative to the outer cylinder, pushing the stitched curved sheet product out from the surface of the outer cylinder, completing the automatic demolding.

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