Automatic thread chain shifting structure, overedger and front thread trimming control method

Abstract

The invention relates to the technical field of sewing machines, in particular to an automatic thread chain shifting structure, an overlock machine and a front thread trimming control method. The automatic thread chain shifting structure comprises a fixing support, a driving assembly, a limiting sleeve and a thread shifting assembly, the driving assembly and the limiting sleeve are both fixedly connected to the fixing support, the thread shifting assembly penetrates through the limiting sleeve, and one end of the thread shifting assembly is in limiting connection with the output end of the driving assembly so that the thread shifting assembly can move under driving of the driving assembly. A guide groove is formed in the inner wall of the limiting sleeve, the guide groove comprises a first straight groove and a first inclined groove, a guide part is arranged on the wire shifting assembly, the guide part is inserted into the guide groove and can move along the guide groove, and when the guide part moves along the first inclined groove, the guide part can drive the wire shifting assembly to rotate. According to the automatic thread braid shifting structure, the overedger and the front thread trimming control method, the problem that the success rate of front thread trimming of an existing overedger is low is solved.

Description

Technical Field

[0001] The present application relates to the technical field of sewing machines, and in particular to an automatic thread-pinning structure, an overlock sewing machine, and a front thread trimming control method. Background Art

[0002] During the fabric processing process, the overlock sewing machine may need to sew the fabric multiple times. After one sewing is completed, the fabric may be cut to form a loose thread chain at the end, which is in the shape of a long and thin braid, called a "thread braid". The thread braid needs to be trimmed in the next sewing to improve the sewing quality.

[0003] At present, the overlock sewing machine uses a thread trimmer to remove the thread braids at the front end of the fabric. The thread trimmer delays the fall of several needles after the fabric passes through the sensor to achieve front thread trimming. However, the direction of the thread braid after it comes out of the presser foot cannot be determined, which leads to a low success rate of front thread trimming and the function of completely shortening the thread ends cannot be achieved. Summary of the Invention

[0004] Based on this, it is necessary to provide an automatic thread braid structure, an overlock sewing machine and a front thread trimming control method to solve the problem of low success rate of the front thread trimming of the existing overlock sewing machine.

[0005] The present application provides an automatic wire-drying braid structure, which includes a fixed bracket, a driving assembly, a limiting sleeve and a wire-drying assembly, the driving assembly and the limiting sleeve are fixedly connected to the fixed bracket, the wire-drying assembly is passed through the limiting sleeve, and one end of the wire-drying assembly is limitatively connected to the output end of the driving assembly so that the wire-drying assembly can move under the drive of the driving assembly; a guide groove is provided on the inner wall of the limiting sleeve, and the guide groove includes a first straight groove and a first oblique groove, the first straight groove extends axially along the limiting sleeve, the first oblique groove is connected to one end of the first straight groove away from the driving assembly, and the first oblique groove and the first straight groove are arranged at an angle; wherein, a guide part is provided on the wire-drying assembly, the guide part is inserted into the guide groove and can move along the guide groove, and when the guide part moves along the first oblique groove, the guide part can drive the wire-drying assembly to rotate.

[0006] In one embodiment, the guide groove further includes a second straight groove and a second oblique groove, the second straight groove extends along the axial direction of the limit sleeve, and the second straight groove is connected to the end of the first oblique groove away from the first straight groove, and the two ends of the second oblique groove are respectively connected to the first straight groove and the end of the second straight groove away from the first oblique groove.

[0007] In one embodiment, the driving assembly includes a driving member and a driving block, the driving member is fixedly connected to the fixed bracket, the driving block is connected to the output end of the driving member, and a limiting slot is provided on the driving block; the wire-drying assembly is provided with a limiting portion, the limiting portion can be inserted into the limiting slot, and abut against the slot wall of the limiting slot, so that the driving block can drive the wire-drying assembly to move.

[0008] In one embodiment, the automatic wire-drying braid structure further includes a first elastic member, the two ends of which are respectively connected to the fixed bracket and the wire-drying assembly, and when the wire-drying assembly moves in a direction away from the driving assembly, the first elastic member can apply a force to the wire-drying assembly to move toward the driving assembly; when the guide portion moves along the first oblique groove, the limiting portion can rotate relative to the driving block and disengage from the limiting groove, so that the wire-drying assembly can move along the second straight groove toward the driving member under the drive of the first elastic member, and rotate along the second oblique groove to reset.

[0009] In one embodiment, the driving block is further provided with a return groove connected to the limit groove, and the driving block is movably connected with a paddle, part of the paddle extends into the return groove and forms the limit groove together with the driving block; when the driving block moves toward the driving member, the limiting portion can move along the return groove and apply force to the paddle to move the paddle, and when the limiting portion moves along the return groove until it is disengaged from the paddle, the paddle can move to reset and stop at the limiting portion.

[0010] In one embodiment, a sliding groove is provided on the fixing bracket, and a boss is provided on the driving block. The boss is inserted into the sliding groove and slidably cooperates with the sliding groove.

[0011] In one embodiment, the limiting sleeve includes an inner sleeve and an outer sleeve, and the outer sleeve is connected to at least part of the circumference of the inner sleeve; wherein, a through groove is provided on the side wall of the inner sleeve, and a protrusion is provided on the inner wall of the outer sleeve, and the protrusion is inserted into the through groove, and the side wall of the protrusion is spaced apart from the side wall of the through groove so that the guide groove can be formed between the side wall of the protrusion and the side wall of the through groove.

[0012] In one embodiment, the limiting sleeve further includes a tightening member, which is sleeved on the outer circumference of the inner sleeve and the outer sleeve to tighten the inner sleeve and the outer sleeve.

[0013] In one embodiment, the wire-drivable assembly includes a movable shaft, a mounting seat, a wire-drivable rod and a second elastic member. The movable shaft is passed through the limiting sleeve, and one end of the movable shaft is connected to the driving assembly, and the other end is connected to the mounting seat; an accommodating cavity is defined in the mounting seat, and the second elastic member is installed in the accommodating cavity; one end of the wire-drivable rod is limitedly installed in the accommodating cavity and abuts against the second elastic member, and the other end extends out of the accommodating cavity for responding to the rotation of the wire-drivable assembly to shift the wire braid.

[0014] The present application also provides a sewing machine, which includes a machine body, a knife group fixing seat, a presser foot arm and the automatic thread braid structure described in any one of the above embodiments; the knife group fixing seat and the presser foot arm are installed on the machine body, and the automatic thread braid structure is arranged between the knife group fixing seat and the presser foot arm, and is connected to the knife group fixing seat.

[0015] The present application also provides a front thread trimming control method, which is implemented based on the above-mentioned overlock sewing machine, and the front thread trimming control method includes: starting sewing, judging whether the sensor is covered by the fabric through the feedback signal of the sensor; if the sensor is covered by the fabric, controlling the thread trimmer to perform a front thread trimming action; if the sensor is not covered by the fabric, using an automatic thread diverting braid structure to divert the thread braids of the fabric, and during the thread diverting action, if it is detected that the sensor is covered by the fabric, then after the thread diverting action is completed, controlling the thread trimmer to perform a front thread trimming action, and if it is not detected that the sensor is covered by the fabric, then after detecting that the sensor is covered by the fabric, controlling the thread trimmer to perform a front thread trimming action.

[0016] Compared with the prior art, the automatic thread-diverting braid structure, overlock sewing machine and front thread trimming control method provided by the present application, when the driving component drives the thread-diverting component, the thread-diverting component can first move in a straight line along the first straight groove through the guide part, thereby gradually approaching the position where the thread braid is connected to the fabric, and when the guide part moves along the first oblique groove, since the first oblique groove and the first straight groove are set at an angle, the guide part will drive the thread-diverting component to rotate. At this time, the end of the thread-diverting component away from the driving component will straighten the thread braid due to the rotation. In this way, the situation of unsuccessful thread cutting or long thread ends due to skewed thread braids is avoided, thereby greatly improving the success rate of thread cutting, which is beneficial to improving the quality of fabric sewing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1A schematic structural diagram of an overlock sewing machine according to an embodiment of the present invention;

[0019] Figure 2 A schematic structural diagram of an automatic wire-drying braid structure according to an embodiment of the present application;

[0020] Figure 3 An exploded view of an automatic wire-drying braid structure according to an embodiment of the present application;

[0021] Figure 4 A schematic structural diagram of a driving block according to an embodiment of the present application;

[0022] Figure 5 A cross-sectional view of a limiting sleeve according to an embodiment of the present application;

[0023] Figure 6 A schematic diagram of the partial structure of an overlock sewing machine according to an embodiment of the present application;

[0024] Figure 7 A schematic diagram of the partial structure of an overlock sewing machine according to an embodiment of the present application;

[0025] Figure 8 A schematic diagram of the partial structure of an overlock sewing machine according to an embodiment of the present application;

[0026] Figure 9 This is a flow chart of a front thread trimmer control method according to an embodiment of the present application.

[0027] The symbols in the figure mean the following:

[0028] 100, automatic wire braiding structure; 10, fixed bracket; 101, slide; 20, drive assembly; 21, drive member; 22, drive block; 2201, limit slot; 2202, return slot; 221, pick; 30, limit sleeve; 301, guide slot; 3011, first straight slot; 3012, first oblique slot; 3013, second straight slot; 3014, second oblique slot; 31, inner sleeve; 3101, through slot; 32, outer sleeve; 321, convex 1. Start; 33. Tightening member; 40. Thread-digging assembly; 41. Guide portion; 42. Limiting portion; 43. Moving shaft; 44. Mounting seat; 4401. Accommodating chamber; 45. Thread-digging rod; 46. Second elastic member; 47. Cover cap; 48. Thread-digging head; 50. First elastic member; 200. Overlock sewing machine; 210. Machine body; 220. Knife assembly fixing seat; 230. Thread cutter; 240. Presser foot arm; 250. Sensor; 260. Needle plate; 300. Thread braid. DETAILED DESCRIPTION

[0029] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0030] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0031] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0032] In this application, unless otherwise expressly specified or limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or that the first feature and the second feature are indirectly in contact through an intermediate medium. Furthermore, a first feature being “above,” “above,” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below,” “below,” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more of the relevant listed items.

[0034] During the fabric processing process, the overlock sewing machine may need to sew the fabric multiple times. After one sewing is completed, the fabric may be cut to form a loose thread chain at the end, which is in the shape of a long and thin braid, called a "thread braid". The thread braid needs to be trimmed in the next sewing to improve the sewing quality.

[0035] At present, the overlock sewing machine uses a thread trimmer to remove the thread braids at the front end of the fabric. The thread trimmer delays the fall of several needles after the fabric passes through the sensor to achieve front thread trimming. However, the direction of the thread braid after it comes out of the presser foot cannot be determined, which leads to a low success rate of front thread trimming and the function of completely shortening the thread ends cannot be achieved.

[0036] See also Figures 1-8 The present application provides an automatic thread-pulling braid structure 100, which is applied to a sewing machine 200 to solve the problem of low success rate of front thread trimming in the existing sewing machine 200.

[0037] Specifically, the automatic wire-drying braid structure 100 includes a fixed bracket 10, a driving component 20, a limiting sleeve 30, and a wire-drying component 40. The driving component 20 and the limiting sleeve 30 are both fixedly connected to the fixed bracket 10. The wire-drying component 40 is inserted into the limiting sleeve 30, and one end of the wire-drying component 40 is limitedly connected to the output end of the driving component 20 so that the wire-drying component 40 can move under the drive of the driving component 20. A guide groove 301 is provided on the inner wall of the limiting sleeve 30. The guide groove 301 includes a first straight groove 3011 and a first oblique groove 3012. The first straight groove 3011 extends along the axial direction of the limiting sleeve 30. The first oblique groove 3012 is connected to the end of the first straight groove 3011 away from the driving component 20, and the first oblique groove 3012 and the first straight groove 3011 are arranged at an angle. The wire-pulling assembly 40 is provided with a guide portion 41 , which is inserted into the guide groove 301 and can move along the guide groove 301 . When the guide portion 41 moves along the first inclined groove 3012 , the guide portion 41 can drive the wire-pulling assembly 40 to rotate.

[0038] It can be understood that when the driving component 20 drives the wire-digging component 40, the wire-digging component 40 can first move in a straight line along the first straight groove 3011 through the guide part 41, thereby gradually approaching the position where the wire braid 300 is connected to the fabric. When the guide part 41 moves along the first oblique groove 3012, since the first oblique groove 3012 and the first straight groove 3011 are set at an angle, the guide part 41 will drive the wire-digging component 40 to rotate. At this time, the end of the wire-digging component 40 away from the driving component 20 will straighten the wire braid 300 due to the rotation. In this way, the situation of unsuccessful thread cutting or long thread ends due to the skewness of the wire braid 300 is avoided, thereby greatly improving the success rate of thread cutting, which is beneficial to improving the quality of fabric sewing.

[0039] In one embodiment, if Figure 2and Figure 3 As shown, the wire-moving assembly 40 includes a movable shaft 43, a mounting base 44, a wire-moving lever 45, and a second elastic member 46. The movable shaft 43 is inserted into the retaining sleeve 30, with one end of the movable shaft 43 connected to the drive assembly 20 and the other end connected to the mounting base 44. The mounting base 44 defines a receiving cavity 4401, within which the second elastic member 46 is mounted. One end of the wire-moving lever 45 is retained within the receiving cavity 4401 and abuts against the second elastic member 46, while the other end extends out of the receiving cavity 4401, thereby moving the wire braid 300 in response to rotation of the wire-moving assembly 40. In other words, the wire-moving lever 45 specifically functions to move the wire braid 300. Furthermore, the provision of the second elastic member 46 allows the wire-moving lever 45 to extend and retract relative to the mounting base 44, thereby ensuring that the wire-moving lever 45 maintains contact with the needle plate 260 (wire braid 300) during rotation and reducing the difficulty of mating between the wire-moving lever 45 and the needle plate 260.

[0040] Specifically, one end of the accommodating chamber 4401 is detachably connected to a cap 47 to facilitate the installation of the second elastic member 46 and the wire-drivable rod 45, and a step structure can be set on the inner wall of the accommodating chamber 4401 and the outer wall of the wire-drivable rod 45 for stop cooperation to prevent the wire-drivable rod 45 from detaching from the mounting seat 44, thereby improving the reliability of the overall structure.

[0041] In order to avoid noise generated when the thread-moving rod 45 contacts the needle plate 260 , a thread-moving head 48 may be installed at the end of the thread-moving rod 45 . The thread-moving head 48 may be made of a flexible material such as rubber and be spherical.

[0042] It should be noted that before the wire-pushing lever 45 rotates with the movable shaft 43, the wire-pushing lever 45 can be tilted outward relative to the wire cutter 230. The tilt angle can be appropriately set according to actual needs. In this way, the wire-pushing lever 45 can reach a wider range, thereby more reliably straightening the skewed wire braid 300.

[0043] In one embodiment, if Figure 5As shown, the guide groove 301 also includes a second straight groove 3013 and a second oblique groove 3014. The second straight groove 3013 extends along the axial direction of the limiting sleeve 30, and the second straight groove 3013 is connected to the end of the first oblique groove 3012 away from the first straight groove 3011. The two ends of the second oblique groove 3014 are respectively connected to the first straight groove 3011 and the second straight groove 3013 away from the first oblique groove 3012. It is easy to understand that when the guide portion 41 moves to the second straight groove 3013 through the first oblique groove 3012, the guide portion 41 can drive the entire wire-digging assembly 40 to retreat along the second straight groove 3013. Since the wire-digging head 48 is still in contact with the wire braid 300 at this time, the wire-digging head 48 can flatten the wire braid 300 as a whole, thereby further improving the success rate of wire cutting and reducing the length of the wire end. When the guide portion 41 moves along the second oblique slot 3014 to the connection position with the first straight slot 3011 , the wire-placing assembly 40 moves back to its original position to facilitate the next wire-placing operation.

[0044] Furthermore, in the process of the wire removal assembly 40 moving and resetting along the second straight groove 3013 and the second oblique groove 3014, in order to improve the efficiency of resetting, in this embodiment, as shown in FIG. Figure 2 and Figure 3 As shown, the automatic wire braid structure 100 further includes a first elastic member 50, the two ends of which are respectively connected to the fixed bracket 10 and the wire braid assembly 40. When the wire braid assembly 40 moves away from the drive assembly 20, the first elastic member 50 can exert a force on the wire braid assembly 40 to move toward the drive assembly 20. In this way, through the pulling of the first elastic member 50, the movement response speed of the wire braid assembly 40 is faster, so that the wire braid 300 is straightened faster, thereby improving the efficiency of wire cutting.

[0045] Since the first elastic member 50 is used for reset in this embodiment, the connection between the wire-drying assembly 40 and the driving assembly 20 needs to be released to avoid interference between the wire-drying assembly 40 and the driving assembly 20. Based on this, in one embodiment, if Figure 2 and Figure 3 Shown, drive assembly 20 comprises driver 21 and driver block 22, and driver 21 is fixedly connected to fixed support 10, and driver 21 can be drive motor or drive cylinder here.Drive block 22 is connected to the output terminal of driver 21, and offers limiting groove 2201 on driver block 22.Line dialing assembly 40 is provided with limiting portion 42, and limiting portion 42 can be inserted in limiting groove 2201, and abuts with the groove wall of limiting groove 2201, so that driver block 22 can drive line dialing assembly 40 to move.And, when guide portion 41 moves along first skewed slot 3012, limiting portion 42 can rotate relative to driver block 22, and breaks away from limiting groove 2201, so that line dialing assembly 40 can move towards the direction close to driver 21 along second straight groove 3013 under the first elastic member 50 drive, and rotates and resets along second skewed slot 3014.

[0046] That is, in the present embodiment, the wire-drying assembly 40 is in active contact with the limiting groove 2201 on the driver block 22 through the limiting portion 42. In this way, when the wire-drying assembly 40 moves along the first straight groove 3011 through the guide portion 41, the limiting portion 42 maintains contact with the inner wall of the limiting groove 2201, so that the driver 21 can synchronously drive the wire-drying assembly 40 to move when driving the driver block 22 to move. And when the guide portion 41 moves along the first oblique groove 3012, as the wire-drying assembly 40 rotates, the limiting portion 42 can also rotate relative to the driver block 22, thereby gradually disengaging from the limiting groove 2201 and releasing the degree of freedom of the wire-drying assembly 40. In this way, the wire-drying assembly 40 can move quickly under the pull of the first elastic member 50 and achieve reset through the second straight groove 3013 and the second oblique groove 3014.

[0047] Furthermore, in one embodiment, Figure 4 As shown, the driving block 22 is further provided with a return groove 2202 that is connected to the limit groove 2201. A paddle 221 is movably connected to the driving block 22. A portion of the paddle 221 extends into the return groove 2202 and forms the limit groove 2201 with the driving block 22. When the driving block 22 moves toward the driving member 21, the limit portion 42 can move along the return groove 2202 and apply force to the paddle 221 to move the paddle 221. Moreover, when the limit portion 42 moves along the return groove 2202 until it is disengaged from the paddle 221, the paddle 221 can move back to its original position and stop at the limit portion 42. It is easy to understand that the paddle 221 acts as abutment against the limit portion 42 to limit the position, thereby enabling the driving block 22 to drive the wire-pulling assembly 40 to move toward the wire braid 300. During the process of moving and resetting the wire-pulling assembly 40, since the speed at which the first elastic member 50 pulls the wire-pulling assembly 40 to move and reset is faster than the speed at which the driving member 21 drives the driving block 22 to recover, the limiting portion 42 will first move to the initial position. Then, as the driving block 22 recovers, the driving block 22 gradually approaches the limiting portion 42, so that the limiting portion 42 can extend into the recovery groove 2202 and force the paddle 221 to move. After the limiting portion 42 continues to move along the recovery groove 2202 until it disengages from the paddle 221, the paddle 221 automatically resets, thereby achieving the stop cooperation with the limiting portion 42. In this way, a complete wire-pulling braid 300 process is completed.

[0048] Here, the movement of the paddle 221 relative to the drive block 22 can be linear movement or rotation. The automatic reset of the paddle 221 can be achieved by controlling the shape of the paddle 221 so that the paddle 221 can be reset by its own gravity. In this embodiment, rotation is used as an example. In this case, the reset of the paddle 221 can also be achieved by providing a torsion spring. Specifically, when one end of the paddle 221 contacts the limit portion 42, the other end of the paddle 221 can contact the drive block 22, thereby preventing the paddle 221 from excessive rotation and preventing the limit portion 42 from being separated from the drive block 22 by the return groove 2202, effectively ensuring the reliability of the connection between the two.

[0049] Furthermore, the driving block 22 and the paddle 221 can be connected by a pin to enable the paddle 221 to rotate relative to the driving block 22. At the same time, the unidirectional rotation stop between the paddle 221 and the driving block 22 can also be achieved by a pin, or of course, it can also be achieved by a step structure on the driving block 22, and the specific configuration can be reasonably determined according to actual needs. Similarly, the guide portion 41 and the limit portion 42 on the wire-pulling assembly 40 can also be configured as a pin or other structure, which is easy to process and form.

[0050] In other embodiments, the wire-pulling assembly 40 may also be moved and reset by the driving assembly 20 . In this case, it is sufficient to ensure that the limiting portion 42 can abut against the inner wall of the limiting groove 2201 and can rotate relative to the limiting groove 2201 .

[0051] In one embodiment, if Figure 2 and Figure 3 As shown, a slide groove 101 is provided on the fixing bracket 10, and a boss (not shown) is provided on the driving block 22, which is inserted into the slide groove 101 and slides with the slide groove 101. In this way, the stability of the movement of the driving block 22 can be further improved, and the connection between the driving block 22 and the wire-pulling assembly 40 can be ensured to be reliable.

[0052] In one embodiment, if Figure 5 As shown, the limiting sleeve 30 includes an inner sleeve 31 and an outer sleeve 32, with the outer sleeve 32 connected to at least a portion of the circumference of the inner sleeve 31. A through slot 3101 is defined on the sidewall of the inner sleeve 31, and a protrusion 321 is provided on the inner wall of the outer sleeve 32. The protrusion 321 is inserted into the through slot 3101, and the sidewalls of the protrusion 321 are spaced apart from the sidewalls of the through slot 3101, so that the sidewalls of the protrusion 321 and the sidewalls of the through slot 3101 form a guide groove 301. This facilitates the connection between the limiting sleeve 30 and the wire removal assembly 40.

[0053] Specifically, when the wire-pulling assembly 40 is connected to the limiting sleeve 30, the movable shaft 43 can be first passed through the inner sleeve 31, and then the guide part 41 can be installed on the movable shaft 43. After the guide part 41 is installed, the outer sleeve 32 is installed on the inner sleeve 31. In this way, while forming the guide groove 301, the guide part 41 is limited in the guide groove 301, and the overall installation is simpler.

[0054] Furthermore, one of the inner sleeve 31 and the outer sleeve 32 is provided with a positioning post, and the other is provided with a positioning hole, and the positioning post is inserted into the positioning hole. In this way, the accuracy of the fit between the inner sleeve 31 and the outer sleeve 32 can be further improved.

[0055] Furthermore, in one embodiment, the limiting sleeve 30 further includes a tightening member 33, which is disposed around the outer circumference of the inner sleeve 31 and the outer sleeve 32 to tighten the inner sleeve 31 and the outer sleeve 32. The tightening member 33 can be an O-ring or the like. This ensures a reliable connection between the inner sleeve 31 and the outer sleeve 32, facilitates disassembly, and reduces the difficulty of subsequent maintenance.

[0056] The automatic wire braiding structure 100 provided by the present application mainly includes the following steps during operation: First, Figure 1 As shown, at this time, the driving assembly 20 and the wire-pulling assembly 40 are both in the initial position. After that, the driving member 21 starts to push the driving block 22 to move. At the same time, the driving block 22 drives the wire-pulling assembly 40 to move synchronously through the cooperation between the paddle 221 and the limiting portion 42. Here, the wire-pulling assembly 40 moves in a straight line along the first straight groove 3011 through the guide portion 41 until the guide portion 41 moves to the connection between the first straight groove 3011 and the second straight groove 3013. At this time, as shown in FIG. Figure 6 As shown, the automatic wire-pulling braid structure 100 is in a critical state where the wire-pulling assembly 40 is about to rotate. Afterwards, the driving member 21 pushes the driving block 22 and drives the wire-pulling assembly 40 to continue moving, and the guide portion 41 moves along the first inclined groove 3012, thereby causing the wire-pulling assembly 40 to move forward in a rotating state until the guide portion 41 moves to the connection between the first inclined groove 3012 and the second straight groove 3013. At this time, Figure 7 As shown, the automatic wire braid structure 100 is in a critical state when the wire assembly 40 is about to generate a reset action. During this period, the wire head 48 realizes the movement of the wire braid 300, and the limiting portion 42 gradually separates from the driving block 22. Figure 8As shown, the first elastic member 50 pulls the wire-drilling assembly 40 to move along the second straight groove 3013 and the second oblique groove 3014 to achieve reset, so that the wire-drilling head 48 straightens the entire wire braid 300. After the driving member 21 drives the driving block 22 to reset, the limiting portion 42 pushes the paddle 221 to re-engage the limiting groove 2201, completing the wire-drilling and reset action. After the entire action is completed, the wire cutter 230 completes the action of cutting the wire braid 300. The entire process can be automated, greatly improving the wire cutting efficiency and ensuring that the length of the thread ends on the fabric is shorter.

[0057] The present application also provides an overlock sewing machine 200, comprising a machine body 210, a knife assembly fixing base 220, a presser foot arm 240, and an automatic thread-pulling braid structure 100 according to any of the above embodiments. The knife assembly fixing base 220 and the presser foot arm 240 are mounted on the machine body 210, and the automatic thread-pulling braid structure 100 is disposed between the knife assembly fixing base 220 and the presser foot arm 240 and connected to the knife assembly fixing base 220. As such, the automatic thread-pulling braid structure 100 of the present application is compact, effectively reducing costs.

[0058] The present application also provides a front thread trimming control method, which is implemented based on the above-mentioned overlock sewing machine 200. Figure 9 As shown, where Y represents yes and N represents no, the front thread trimming control method includes:

[0059] Start sewing and determine whether the sensor 250 is covered by the fabric through the feedback signal of the sensor 250;

[0060] If the sensor 250 is covered by the fabric, the thread cutter 230 is controlled to perform a front thread trimming action;

[0061] If the sensor 250 is not covered by the cloth, the automatic wire braid structure 100 is used to spread the wire braid 300 of the cloth. During the spreading action, if it is detected that the sensor 250 is covered by the cloth, the wire cutter 230 is controlled to perform a front wire cutting action after the spreading action is completed. If it is not detected that the sensor 250 is covered by the cloth, the wire cutter 230 is controlled to perform a front wire cutting action after it is detected that the sensor 250 is covered by the cloth.

[0062] Normally, the sensor 250 will control the thread trimmer 230 to drop and cut the thread after delaying a few stitches after recognizing the fabric. Based on this, if the present application detects that the sensor 250 is covered by the fabric at the beginning of sewing, the thread-digging action will not be performed to avoid the thread trimmer 230 from falling and interfering with the thread-digging assembly 40, thereby causing damage to the thread-digging assembly 40. If the sensor 250 is not covered by the fabric, the thread-digging action can be performed. During the thread-digging action, even if the fabric moves to the sensor 250, the thread-digging will not be performed temporarily. Instead, the thread trimmer 230 will be controlled to cut the thread after the entire thread-digging and resetting action is completed, thereby ensuring the safety of thread cutting.

[0063] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of patent protection for the present application shall be determined by the appended claims.

Claims

1. An automatic wire braid structure, characterized in that: The invention comprises a fixed bracket (10), a driving component (20), a limiting sleeve (30) and a wire-drivable component (40), wherein the driving component (20) and the limiting sleeve (30) are both fixedly connected to the fixed bracket (10), the wire-drivable component (40) is passed through the limiting sleeve (30), and one end of the wire-drivable component (40) is limitedly connected to the output end of the driving component (20), so that the wire-drivable component (40) can move under the drive of the driving component (20); A guide groove (301) is provided on the inner wall of the limiting sleeve (30), and the guide groove (301) includes a first straight groove (3011) and a first oblique groove (3012), wherein the first straight groove (3011) extends along the axial direction of the limiting sleeve (30), and the first oblique groove (3012) is connected to an end of the first straight groove (3011) away from the driving assembly (20), and the first oblique groove (3012) and the first straight groove (3011) are arranged at an angle; The wire-pulling assembly (40) is provided with a guide portion (41), which is inserted into the guide groove (301) and can move along the guide groove (301), and when the guide portion (41) moves along the first inclined groove (3012), the guide portion (41) can drive the wire-pulling assembly (40) to rotate.

2. The automatic wire braid structure according to claim 1, characterized in that: The guide groove (301) further comprises a second straight groove (3013) and a second oblique groove (3014), wherein the second straight groove (3013) extends along the axial direction of the limiting sleeve (30), and the second straight groove (3013) is connected to an end of the first oblique groove (3012) away from the first straight groove (3011), and the two ends of the second oblique groove (3014) are respectively connected to the first straight groove (3011) and an end of the second straight groove (3013) away from the first oblique groove (3012).

3. The automatic wire braid structure according to claim 2, characterized in that: The driving assembly (20) comprises a driving member (21) and a driving block (22), wherein the driving member (21) is fixedly connected to the fixed bracket (10), the driving block (22) is connected to the output end of the driving member (21), and a limiting slot (2201) is provided on the driving block (22); The wire-driving assembly (40) is provided with a limiting portion (42), which can be inserted into the limiting groove (2201) and abutted against the groove wall of the limiting groove (2201), so that the driving block (22) can drive the wire-driving assembly (40) to move.

4. The automatic wire braid structure according to claim 3, characterized in that: The automatic wire-drying braid structure further comprises a first elastic member (50), two ends of which are respectively connected to the fixed bracket (10) and the wire-drying assembly (40), and when the wire-drying assembly (40) moves in a direction away from the driving assembly (20), the first elastic member (50) can exert a force on the wire-drying assembly (40) to move toward the driving assembly (20); When the guide portion (41) moves along the first inclined groove (3012), the limiting portion (42) can rotate relative to the driving block (22) and disengage from the limiting groove (2201), so that the wire-pulling assembly (40) can move along the second straight groove (3013) toward the driving member (21) under the drive of the first elastic member (50), and rotate and reset along the second inclined groove (3014).

5. The automatic wire braid structure according to claim 4, characterized in that: The driving block (22) is further provided with a return groove (2202) communicating with the limiting groove (2201); the driving block (22) is movably connected with a paddle (221); a portion of the paddle (221) extends into the return groove (2202) and forms the limiting groove (2201) with the driving block (22); When the driving block (22) moves toward the driving member (21), the limiting portion (42) can move along the return groove (2202) and exert force on the paddle (221) to move the paddle (221), and when the limiting portion (42) moves along the return groove (2202) to disengage from the paddle (221), the paddle (221) can move to reset and stop at the limiting portion (42).

6. The automatic wire braid structure according to claim 3, characterized in that: A sliding groove (101) is provided on the fixing bracket (10), and a boss is provided on the driving block (22). The boss is inserted into the sliding groove (101) and slidably engages with the sliding groove (101).

7. The automatic wire braid structure according to any one of claims 1 to 6, characterized in that: The limiting sleeve (30) comprises an inner sleeve (31) and an outer sleeve (32), wherein the outer sleeve (32) is connected to at least a portion of the circumference of the inner sleeve (31); A through groove (3101) is provided on the side wall of the inner sleeve (31), and a protrusion (321) is provided on the inner wall of the outer sleeve (32), wherein the protrusion (321) is inserted into the through groove (3101), and the side wall of the protrusion (321) is spaced apart from the side wall of the through groove (3101), so that the side wall of the protrusion (321) and the side wall of the through groove (3101) can enclose the guide groove (301).

8. The automatic wire braid structure according to claim 7, characterized in that: The limiting sleeve (30) further includes a tightening member (33), wherein the tightening member (33) is sleeved on the outer periphery of the inner sleeve (31) and the outer sleeve (32) to tighten the inner sleeve (31) and the outer sleeve (32).

9. The automatic wire braid structure according to claim 1, characterized in that: The wire-drivable assembly (40) comprises a movable shaft (43), a mounting seat (44), a wire-drivable rod (45) and a second elastic member (46); the movable shaft (43) is passed through the limiting sleeve (30), and one end of the movable shaft (43) is connected to the driving assembly (20), and the other end is connected to the mounting seat (44); An accommodating cavity (4401) is provided in the mounting seat (44), the second elastic member (46) is installed in the accommodating cavity (4401), one end of the wire-moving rod (45) is limitedly installed in the accommodating cavity (4401) and abuts against the second elastic member (46), and the other end extends out of the accommodating cavity (4401) for moving the wire braid (300) in response to the rotation of the wire-moving assembly (40).

10. An overlock sewing machine, characterized in that: It comprises a machine body (210), a knife group fixing seat (220), a presser foot arm (240), and an automatic wire braiding structure according to any one of claims 1 to 9; The knife group fixing seat (220) and the presser foot arm (240) are mounted on the machine body (210); the automatic wire braiding structure is arranged between the knife group fixing seat (220) and the presser foot arm (240), and is connected to the knife group fixing seat (220).

11. A front trimmer control method, characterized in that: The front thread trimming control method is implemented based on the overlock sewing machine according to claim 10, and the front thread trimming control method includes: Start sewing, and determine whether the sensor (250) is covered by the fabric through the feedback signal of the sensor (250); If the sensor (250) is covered by the fabric, the thread cutter (230) is controlled to perform a front thread cutting action; If the sensor (250) is not covered by the fabric, the automatic wire braid structure is used to perform wire braiding on the fabric wire braid (300); during the wire braiding action, if it is detected that the sensor (250) is covered by the fabric, then after the wire braiding action is completed, the wire cutter (230) is controlled to perform a front wire cutting action; if it is not detected that the sensor (250) is covered by the fabric, then after it is detected that the sensor (250) is covered by the fabric, the wire cutter (230) is controlled to perform a front wire cutting action.

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