Cryptic seam method and overlock machine

Abstract

The application relates to an encryption sewing method and a lockstitch machine. The encryption sewing method comprises the following steps: a, adjusting the rotating angle alpha of a motor, controlling the position of a presser plate to be fixed relative to a needle plate, and controlling the moving track of a feed dog to move a preset distance x away from the presser plate; b, a feed dog driving structure drives the feed dog to move along the moving track, drives the cloth on the needle plate to move, and performs encryption sewing on the cloth; the moving track of the feed dog is controlled to move away from the presser plate by adjusting the motor, so that the single cloth feeding distance d of the feed dog is reduced, and the sewing stitch of the cloth is reduced; meanwhile, the position of the presser plate is controlled to be fixed relative to the needle plate by the adjusting motor, so that the change of the single cloth feeding distance d of the feed dog is only affected by the preset distance x, variables introduced due to the movement of the presser plate are reduced, the user can control the single cloth feeding distance d of the feed dog, and the adjusting difficulty is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of the feeding mechanism of a coverstitch machine, and in particular to a method for coverstitching, a coverstitching device and a coverstitch machine. BACKGROUND

[0002] At present, when a garment factory is sewing a fabric cover, it needs to cut the thread, which is divided into front cutting and back cutting. The thread after cutting should not be too long or too short. If the thread is too long, it needs to be processed manually for the second time. If the thread is too short, the thread ring is easy to scatter, which leads to unqualified sewing of the fabric.

[0003] After the fabric is coverstitched, even if the thread is short, the thread braid is not easy to come off and scatter, which can effectively improve the quality of cutting. The existing sewing machine usually adjusts the needle spacing by adjusting the electric control parameters, so as to complete the coverstitching of the fabric. However, the mainstream model of the coverstitch machine cannot adjust the needle spacing by adjusting the electric control parameters. SUMMARY

[0004] Therefore, it is necessary to provide a method for coverstitching, a coverstitching device and a coverstitch machine suitable for the mainstream model of the coverstitch machine to solve the problem that the mainstream model of the coverstitch machine cannot adjust the needle spacing by adjusting the electric control parameters.

[0005] The present application provides a method for coverstitching, which comprises the following steps:

[0006] a. Adjusting the rotation angle α° of the motor, controlling the position of the presser plate fixed relative to the needle plate, and controlling the moving track of the feed dog to move a preset distance x away from the presser plate;

[0007] b. The feed dog driving structure drives the feed dog to move along the moving track, drives the fabric on the needle plate to move, and coverstitches the fabric.

[0008] 2. The method for coverstitching according to claim 1, further comprising

[0009] c1. Judging whether the number of coverstitching n2 is less than the second preset number of needles N2. If yes, step b is executed. If no, the rotation angle α° of the motor is adjusted, the position of the presser plate is controlled to be fixed relative to the needle plate, and the moving track of the feed dog is controlled to reset.

[0010] In one embodiment, step a further comprises

[0011] The rotation speed of the main shaft motor is reduced from v1 to v2.

[0012] 4. The method for coverstitching according to claim 3, further comprising

[0013] c2 judging whether the number of the encryption stitches n2 is less than the second preset number N2, if yes, executing step b, if no, the rotating speed of the main shaft motor is increased from v2 to v1, and the motor reverse angle a° is adjusted, the position of the presser plate relative to the needle plate is fixed, and the moving track of the feed dog is reset.

[0014] In one of the embodiments, after step c2, it further includes

[0015] d the feed dog driving structure drives the feed dog to move along the moving track, and drives the cloth on the needle plate to move, and the cloth is normally sewed.

[0016] In one of the embodiments, before step a, it further includes

[0017] e the feed dog driving structure drives the feed dog to move along the moving track, and drives the cloth on the needle plate to move, and the cloth is normally sewed.

[0018] f judging whether the cloth covers the first sensor, if no, executing step e, if yes, after the first preset number N1 of stitches, executing step a.

[0019] 7. The encryption sewing method according to claim 6, wherein after step d, it further includes

[0020] g judging whether the cloth covers the second sensor, if no, executing step d, if yes, the front thread cutting is performed, and step d is executed until the cloth leaves the first sensor;

[0021] h after the first preset number N1 of stitches, executing step a, step b, step c2 and step i in sequence.

[0022] i judging whether the cloth leaves the second sensor, if no, continuing to execute step c2, if yes, the rear thread cutting is performed, and the sewing is ended.

[0023] The second aspect of the present application provides an encryption sewing device for executing the encryption sewing method, which comprises a machine body, a cloth feeding assembly, a feed dog driving structure and a presser plate. The cloth feeding assembly comprises a toothed frame and a feed dog fixed to one end of the toothed frame. The feed dog driving structure is arranged on the machine body and connected with the toothed frame, and is used for driving the feed dog to move along a moving track through the toothed frame. The moving track passes through the presser plate. The encryption sewing device further comprises an adjusting motor and a track adjusting assembly. The adjusting motor is fixed to the machine body and can drive the presser plate to move. The track adjusting assembly is connected with the output shaft of the adjusting motor and the toothed frame. The adjusting motor has an encryption sewing adjusting range β. Within the encryption sewing adjusting range β, the adjusting motor can drive the toothed frame to move through the track adjusting assembly, so as to change the position of the moving track in the direction of approaching or moving away from the presser plate, and the presser plate is fixed relative to the machine body.

[0024] In one embodiment, the encryption seam device comprises a presser plate structure, the presser plate structure comprises the presser plate, a presser plate cam, a presser plate swing arm and a linkage set, the presser plate cam is fixed to the output shaft of the adjusting motor, the presser plate swing arm is rotationally connected to the machine body and abuts against the outer circumferential surface of the presser plate cam, and the linkage set connects the presser plate swing arm and the presser plate, so that the adjusting motor can drive the presser plate to move in the direction of approaching or moving away from the feed dog; the outer circumferential surface of the presser plate cam comprises a base circle segment, the radius of the base circle segment is equal at all places; within the encryption seam rotation angle range β, the base circle segment abuts against the presser plate swing arm.

[0025] The third aspect of the present application provides a zigzag sewing machine comprising the above encryption seam device.

[0026] The above encryption seam method controls the movement trajectory of the feed dog to move away from the presser plate by the adjusting motor, so that the single feed distance d of the feed dog is reduced, and the sewing stitch of the fabric is reduced; at the same time, since the adjusting motor also controls the relative fixation of the presser plate, the change of the single feed distance d of the feed dog is only affected by the preset distance x, which reduces the variable introduced by the movement of the presser plate, facilitates the user to control the single feed distance d of the feed dog, and reduces the adjustment difficulty. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a flowchart of the encryption seam method of the present application in one embodiment;

[0028] Figure 2 FIG. 2 is a schematic diagram of the movement trajectory of the feed dog and the presser plate of the encryption seam device of the present application in the ordinary sewing state;

[0029] Figure 3 FIG. 3 is a schematic diagram of the movement trajectory of the feed dog and the presser plate of the encryption seam device of the present application in the encryption seam state;

[0030] Figure 4 、 Figure 5 、 Figure 6 and Figure 7 are flowcharts of the encryption seam method of the present application in other embodiments;

[0031] Figure 8 FIG. 7 is a schematic diagram of the three-dimensional structure of the encryption seam device of the present application;

[0032] Figure 9 is Figure 8 a schematic diagram of the three-dimensional structure of the presser plate structure in FIG. 6;

[0033] Figure 10 is Figure 8 a front view structural schematic diagram of the presser plate cam in FIG. 6;

[0034] Figure 11 For Figure 8 Schematic perspective view of the step feeding tooth driving structure;

[0035] Figure 12 For Figure 8 Schematic perspective view of the fabric feeding assembly;

[0036] Figure 13 For Figure 8 Schematic perspective view of the presser cam hidden structure;

[0037] Figure 14 For Figure 13 Schematic perspective view of the trajectory adjusting assembly.

[0038] Fig. 20, needle plate; 30, fabric feeding assembly; 31, tooth rack; 311, first sliding groove; 312, second sliding groove; 32, step feeding tooth; 40, step feeding tooth driving structure; 41, main shaft; 42, first eccentric shaft; 43, first sliding block; 50, adjusting motor; 60, trajectory adjusting assembly; 61, adjusting cam; 62, adjusting swing arm; 63, adjusting pivot; 64, second sliding block; 70, presser plate structure; 71, presser plate; 72, presser cam; 721, base circle segment; 73, presser swing arm; 74, connecting rod set; 741, hook; 742, first connecting rod; 743, presser pivot; 744, second connecting rod; 745, torsional spring; 1, moving trajectory; 2, first direction. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings. In the following description, a large number of specific details are set forth in order to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the concept of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0040] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0041] In addition, the terms "first", "second", etc. are used herein for descriptive purposes only and should not be construed as indicating or implying relative importance or an ordered sequence. Thus, features defined with "first", "second" etc. can include at least one of the features, explicitly or implicitly.

[0042] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0044] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can be a middle element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not the only implementation.

[0045] Please refer to Figure 1 , Figure 2 and Figure 3 , the present application first provides a method for encrypting a seam, comprising the following steps:

[0046] S300, adjust the rotation angle of the motor α°, control the position of the pressing plate relative to the needle plate to be fixed, and control the moving track of the step tooth to move a preset distance x away from the pressing plate;

[0047] S400, the step tooth driving structure drives the step tooth to move along the moving track, drives the cloth on the needle plate to move, and encrypts the cloth.

[0048] The moving track of the step tooth is generally elliptical. In a normal sewing state, the upper half of the elliptical moving track intersects with the plane where the pressing plate is located, and the distance between the two intersection points is the single step distance d of the step tooth. By controlling the moving track of the step tooth to move away from the pressing plate, the distance between the two intersection points of the moving track and the plane where the pressing plate is located is reduced, so that the single step distance d of the step tooth is reduced, and the encryption sewing effect is achieved.

[0049] The preset distance x can be set according to the single step distance d of the step tooth required in the encryption sewing state. As long as the moving track of the step tooth moves away from the pressing plate by the preset distance x, there are still two intersection points between the moving track and the plane where the pressing plate is located.

[0050] It should be noted that, since the position of the pressing plate relative to the needle plate is fixed during the adjustment of the rotation angle a° of the motor, the change of the single step distance d of the step tooth is only affected by the preset distance x, which reduces the variable introduced by the movement of the pressing plate, facilitates the user to control the single step distance d of the step tooth, and reduces the adjustment difficulty.

[0051] Please refer to Figure 4 As shown in FIG. 1,

[0052] S500a, whether the encryption sewing needle number n2 is less than the second preset needle number N2 is judged, if yes, step S400 is executed, if not, the rotation angle a° of the motor is adjusted, the position of the pressing plate relative to the needle plate is fixed, and the moving track of the step tooth is reset.

[0053] Here, the second preset needle number N2 is a needle number preset according to actual encryption sewing needs, and the encryption sewing needle number n2 is the running needle number recognized by the sewing machine since the completion of step 300.

[0054] If the encryption sewing needle number n2 is less than the second preset needle number N2, the encryption sewing length does not reach the preset requirement, at this time step S400 is executed to continue encryption sewing; otherwise, the encryption sewing length reaches the requirement, the moving track of the step tooth is reset by adjusting the motor, so as to facilitate the normal operation of subsequent sewing work.

[0055] In some embodiments, step S500a can also be: whether the encryption sewing time t2 is less than the second preset time T2 is judged, if yes, step S400 is executed, if not, the rotation angle a° of the motor is adjusted, the position of the pressing plate relative to the needle plate is fixed, and the moving track of the step tooth is reset.

[0056] Here, the encryption seam time t2 and the second preset time T2 are both a period of time, wherein the second preset time T2 is a period of time preset according to actual encryption seam needs, and the encryption seam time t2 is the machine running time recognized by the sewing machine since step 300 is completed.

[0057] Please refer to Figure 5 As shown in the figure, in some embodiments, step S300 further includes

[0058] The rotation speed of the main shaft motor is reduced from v1 to v2.

[0059] The rotation speed v1 is greater than the rotation speed v2. Since the rotation speed v1 of the main shaft motor is relatively fast, the reaction time of the adjusting motor is relatively short in step S300. If the adjusting motor does not control the movement of the feed dog at the correct time, it may cause the stitch length of the encryption seam to be unstable, and even may miss the set encryption seam area of the cloth. At the same time, the main shaft motor is slowed down in step S300, which can increase the reaction time of the adjusting motor, thereby increasing the stitch length stability of the encryption seam and the success rate of the encryption seam.

[0060] Please refer to Figure 5 As shown in the figure, in some embodiments, step S400 further includes

[0061] S500b, determine whether the encryption seam stitch number n2 is less than the second preset stitch number N2. If yes, execute step S400. If no, the rotation speed of the main shaft motor is increased from v2 to v1, and the reverse angle a° of the adjusting motor is adjusted. The position of the presser foot relative to the needle plate is fixed, and the movement trajectory of the feed dog is reset.

[0062] Please refer to Figure 6 As shown in the figure, in some embodiments, step S500b further includes

[0063] S600, the feed dog driving structure drives the feed dog to move along the movement trajectory, drives the cloth on the needle plate to move, and performs ordinary sewing on the cloth.

[0064] Here, the ordinary sewing refers to that the stitch length is restored to the state before the movement trajectory of the feed dog is changed in step S300, and the rotation speed of the main shaft is returned to v1 for sewing, so as to realize the sewing work on the cloth with a larger stitch length and a faster sewing speed relative to the encryption seam state.

[0065] Please refer to Figure 7 As shown in the figure, in some embodiments, step S300 further includes

[0066] S100, the feed dog driving structure drives the feed dog to move along the movement trajectory, drives the cloth on the needle plate to move, and performs ordinary sewing on the cloth.

[0067] S200, judging whether the cloth covers the first sensor, if not, executing step S100, if yes, executing step S300 after not less than the first preset needle number N1.

[0068] The first preset frame number N1 is the running needle number of the sewing machine in the process that the front edge of the cloth is sent from the position of the first sensor to the sewing position of the sewing machine. Since there is still a certain distance between the position of the first sensor and the sewing position of the sewing machine, step S300 is executed after the first preset frame number N1 is delayed after the first sensor detects the cloth, so as to ensure that the front edge of the cloth is located at the sewing position or has covered the sewing position when the sewing machine executes step S300, thereby ensuring the normal performance of the encryption sewing.

[0069] In some embodiments, step S200 can also be: judging whether the cloth covers the first sensor, if not, executing step S100, if yes, executing step S300 after not less than the first preset time T1.

[0070] Please refer to Figure 7 In some embodiments, after step S600, there is also

[0071] S700 judges whether the cloth covers the second sensor, if not, executing step S600, if yes, performing front thread cutting and executing steps S600 to S900 in sequence after the cloth leaves the first sensor;

[0072] S800 executes steps S300, S400, S500b and S900 in sequence after not less than the first preset needle number N1.

[0073] S900 judges whether the cloth leaves the second sensor, if not, continuing to execute step S500b, if yes, performing rear thread cutting and ending the sewing.

[0074] The thread cutting of the cloth is usually divided into front thread cutting and rear thread cutting, wherein steps S100 to S500b are encryption sewing performed for facilitating the front thread cutting, and after the front thread cutting is completed in step S700, the rear thread cutting of the cloth can be completed through steps S800 and S900.

[0075] In step S700, the cloth leaves the first sensor, that is, the rear edge of the cloth leaves the first sensor, at this time, there is still a certain distance between the rear edge of the cloth and the sewing position of the sewing machine, and through step S800, the first preset needle number N1 is delayed, so as to ensure that the rear edge of the cloth is located at the sewing position or has covered the sewing position when step S300 is executed again, thereby ensuring the normal performance of the encryption sewing.

[0076] Please combine Figure 2 , Figure 3 and Figure 8In the second aspect, the application provides an encryption sewing device for performing the encryption sewing method, which comprises a machine body (not shown in the figure), a cloth feeding assembly 30, a step tooth driving structure 40, and a pressing plate 71. The cloth feeding assembly 30 comprises a tooth rack 31 and a step tooth 32 fixed to one end of the tooth rack 31. The step tooth driving structure 40 is arranged on the machine body and connected with the tooth rack 31, and is used for driving the step tooth 32 to move along a movement track 1 through the tooth rack 31. The movement track 1 passes through the pressing plate 71. The encryption sewing device further comprises an adjusting motor 50 and a track adjusting assembly 60. The adjusting motor 50 is fixed to the machine body and can drive the pressing plate 71 to move. The track adjusting assembly 60 is connected with the output shaft of the adjusting motor 50 and the tooth rack 31. The adjusting motor 50 has an encryption sewing adjusting range β. Within the encryption sewing adjusting range β, the adjusting motor 50 can drive the tooth rack 31 to move through the track adjusting assembly 60, so as to change the position of the movement track 1 in the direction of approaching or moving away from the pressing plate 71, and the pressing plate 71 is fixed relative to the machine body.

[0077] The adjusting motor 50 is used for driving the pressing plate 71 to move and driving the movement track 1 of the step tooth 32 to move. The movement of the pressing plate 71 can meet the clamping requirements of cloth with different thicknesses, and facilitates the installation and taking of the cloth. The movement of the movement track 1 of the step tooth 32 can realize the adjustment of the single cloth feeding distance d of the step tooth.

[0078] In the application, by running the adjusting motor 50 within the encryption sewing adjusting range β, the position of the pressing plate 71 relative to the machine body can be ensured to be fixed during the movement of the movement track 1 of the step tooth 32, so as to avoid the adjustment of the single cloth feeding distance d of the step tooth being affected by the movement of the pressing plate 71, reduce the introduction of variables, facilitate the user to control the single cloth feeding distance d of the step tooth, and reduce the adjustment difficulty.

[0079] Please refer to Figure 8 , Figure 9 and Figure 10 for the following. In some embodiments, the encryption sewing device comprises a pressing plate structure 70, which comprises the pressing plate 71, a pressing plate cam 72, a pressing plate swing arm 73, and a connecting rod set 74. The pressing plate cam 72 is fixed to the output shaft of the adjusting motor 50. The pressing plate swing arm 73 is rotationally connected to the machine body and abuts against the outer circumferential surface of the pressing plate cam 72. The connecting rod set 74 connects the pressing plate swing arm 73 and the pressing plate 71, so that the adjusting motor 50 can drive the pressing plate 71 to move in the direction of approaching or moving away from the step tooth 32. The outer circumferential surface of the pressing plate cam 72 comprises a base circle segment 721, and the radius of the base circle segment 721 is equal everywhere. Within the encryption sewing rotation angle range β, the base circle segment 721 abuts against the pressing plate swing arm 73.

[0080] Of course, the pressing plate structure 70 can also adopt other common transmission structures, such as a half gear structure, etc., as long as the pressing plate 71 is not moved by the adjusting motor 50 when the adjusting motor 50 operates within the encryption seam rotation angle range β.

[0081] In the encryption seam method, the rotation angle α of the adjusting motor 50 is less than the encryption seam rotation angle range β.

[0082] Please refer to Figure 9 In some embodiments, as shown in the drawings, the connecting rod set 74 includes a hook 741, a first connecting rod 742, a pressing plate rotation shaft 743, a second connecting rod 744, and a torsion spring 745. The pressing plate rotation shaft 743 is rotationally connected to the machine body. The first connecting rod 742 and the second connecting rod 744 are both fixed to the pressing plate rotation shaft 743. The end of the first connecting rod 742 away from the pressing plate rotation shaft 743 is fixed to the pressing plate swing arm 73 through the hook 741. The end of the second connecting rod 744 away from the pressing plate rotation shaft 743 is fixed to the pressing plate 71. The torsion spring 745 is sleeved on the pressing plate rotation shaft 743, and the two ends are respectively fixed to the first connecting rod 742 and the machine body.

[0083] Please refer to Figure 8 , Figure 11 and Figure 12 In some embodiments, as shown in the drawings, the step feeding tooth driving structure 40 includes a vertical driving assembly and a horizontal driving assembly (not shown in the drawings). The vertical driving assembly includes a main shaft motor (not shown in the drawings), a main shaft 41, a first eccentric shaft 42, and a first sliding block 43. The main shaft motor is fixed to the machine body and used to drive the main shaft 41 to rotate. The normal end of the first eccentric shaft 42 is fixed to the main shaft 41, and the eccentric end is rotationally connected to the first sliding block 43. The tooth frame 31 is provided with a first sliding groove 311 in the first direction 2. The first sliding block 43 is slidingly connected to the first sliding groove 311.

[0084] Please refer to Figure 13 and Figure 14 In some embodiments, as shown in the drawings, the trajectory adjusting assembly 60 includes an adjusting cam 61, an adjusting swing arm 62, an adjusting rotation shaft 63, and a second sliding block 64. The adjusting cam 61 is fixed to the output shaft of the adjusting motor 50. The adjusting rotation shaft 63 is an eccentric shaft and is rotationally connected to the machine body. The adjusting swing arm 62 and the second sliding block 64 are both fixed to the adjusting rotation shaft 63. The end of the adjusting swing arm 62 away from the adjusting rotation shaft 63 abuts against the outer circumferential surface of the adjusting cam 61. The tooth frame 31 is provided with a second sliding groove 312 in the first direction 2. The second sliding block 64 is slidingly connected to the second sliding groove 312.

[0085] In some embodiments, the machine body and / or the needle plate 20 are fixed with a first sensor (not shown in the drawings) and a second sensor (not shown in the drawings) corresponding to the step feeding tooth 32 in the first direction 2.

[0086] The third aspect of the present application provides a lockstitch machine comprising the above-mentioned encryption stitching device.

[0087] The technical features of the above-mentioned embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present disclosure.

[0088] The above-mentioned embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A method for creating denser seams, characterized in that, Includes the following steps; a. Adjust the motor rotation angle α° to control the pressure plate to be fixed relative to the needle plate, and at the same time control the movement trajectory of the feed tooth to move a preset distance x away from the pressure plate, and the speed of the main spindle motor decreases from v1 to v2. b. The feed tooth drive structure drives the feed tooth to move along the moving trajectory, which in turn moves the fabric on the needle plate to perform dense stitching on the fabric. c2 determines whether the number of stitches n2 is less than the second preset number of stitches N2. If yes, execute step b. If no, the speed of the main spindle motor increases from v2 to v1, and the motor reverse angle α° is adjusted at the same time to fix the position of the pressure plate relative to the needle plate and to reset the movement trajectory of the feed tooth. The dense sewing method is executed by a dense sewing device, which includes a machine body, a fabric feeding assembly (30), a feed dog drive structure (40), and a pressure plate (71). The fabric feeding assembly (30) includes a feed dog frame (31) and a feed dog (32) fixed to one end of the feed dog frame (31). The feed dog drive structure (40) is disposed on the machine body and connected to the feed dog frame (31), and is used to drive the feed dog (32) to move along a movement trajectory (1) through the feed dog frame (31). The movement trajectory (1) passes through the pressure plate (71). The densification device also includes an adjustment motor (50) and a trajectory adjustment component (60). The adjustment motor (50) is fixed to the machine body and can drive the pressure plate (71) to move. The trajectory adjustment component (60) is connected to the output shaft of the adjustment motor (50) and the dental frame (31). The adjustment motor (50) has a densification adjustment range β. Within the density seam adjustment range β, the adjustment motor (50) can drive the dental frame (31) to move via the trajectory adjustment component (60), thereby changing the position of the movement trajectory (1) in the direction of approaching or moving away from the pressure plate (71), and the pressure plate (71) is fixed relative to the machine body.

2. The method for increasing the density of seams according to claim 1, characterized in that, Step b is followed by c1 determines whether the number of stitches n2 is less than the second preset number of stitches N2. If yes, proceed to step b. If no, adjust the motor reverse angle α° to fix the position of the pressure plate relative to the needle plate, and simultaneously control the movement trajectory of the feed teeth to reset.

3. The method for increasing the density of seams according to claim 1, characterized in that, Step c2 is followed by The feed tooth drive structure drives the feed tooth to move along the moving trajectory, which in turn moves the fabric on the needle plate to perform ordinary sewing on the fabric.

4. The method for increasing the density of seams according to claim 3, characterized in that, Step a includes The feed dog drive structure drives the feed dog to move along the moving trajectory, which in turn moves the fabric on the needle plate to perform ordinary sewing. f determines whether the fabric covers the first sensor. If not, proceed to step e. If yes, proceed to step a after the number of stitches is not less than the first preset number of stitches N1.

5. The method for increasing the density of seams according to claim 4, characterized in that, Step d is followed by g determines whether the fabric is covering the second sensor. If not, proceed to step d. If yes, perform a pre-cutting and proceed to step d until the fabric leaves the first sensor. After h is not less than the first preset number of needles N1, steps a, b, c2 and i are executed sequentially. i determines whether the fabric has left the second sensor. If not, continue to step c2. If yes, perform back thread trimming and end sewing.

6. The method for increasing the density of seams according to claim 1, characterized in that, The dense stitching device includes a pressure plate structure (70), which includes a pressure plate (71), a pressure plate cam (72), a pressure plate swing arm (73), and a linkage group (74). The pressure plate cam (72) is fixed to the output shaft of the adjusting motor (50). The pressure plate swing arm (73) is rotatably connected to the machine body and abuts against the outer peripheral surface of the pressure plate cam (72). The linkage group (74) connects the pressure plate swing arm (73) and the pressure plate (71) so that the adjusting motor (50) can drive the pressure plate (71) to move in a direction closer to or away from the feed tooth (32). The outer circumferential surface of the pressure plate cam (72) includes a base circle segment (721), the radius of which is equal everywhere; within the density seam adjustment range β, the base circle segment (721) abuts against the pressure plate swing arm (73).

7. An overlock sewing machine, characterized in that, The method for performing the seam-sealing method of claim 1 includes the seam-sealing device.

Images