Synchronous-drive thread shearing and clamping mechanism of sewing machine

Abstract

The invention discloses a synchronous-drive thread shearing and clamping mechanism of a sewing machine. The synchronous-drive thread shearing and clamping mechanism comprises a driving motor, a thread clamping cam, a thread shearing cam, a thread shearing driving rod set, a thread clamping driving rod set, a thread shearing assembly and a thread clamping assembly. The thread trimming cam and the thread clamping cam are provided with a first oval cam groove and a second oval cam groove respectively, the thread clamping cam and the thread trimming cam are both in linkage with the driving motor, the thread trimming cam and the thread clamping cam are arranged in a mirror image mode, and the directions of the first cam groove and the second cam groove are opposite. A first rolling wheel is arranged on the first cam groove in a sliding mode, and the thread trimming driving rod set is connected with the first rolling wheel and the thread trimming assembly; a second roller is arranged on the second cam groove in a sliding mode, and the wire clamping driving rod set is connected with the second roller and the wire clamping assembly. According to the invention, the same motor is adopted for driving to realize synchronous and coordinated operation of thread trimming and thread clamping, the transmission structure is optimized, the thread trimming and thread clamping stability can be effectively improved, and the bird nest phenomenon is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of sewing equipment, and particularly relates to a same-drive thread cutting and clamping mechanism for a sewing machine. Background Art

[0002] Sewing machines are widely used in industries such as shoemaking, handbags, luggage, clothing, and automotive interiors. Sewing machines can sew fabrics such as cotton, linen, silk, wool, and artificial fibers, as well as sewing products such as leather, plastic, and paper. The sewn stitches are neat, beautiful, flat, and firm. The sewing speed is fast and it is easy to use. When the existing sewing machine starts sewing, the material difference or the length of the surface thread end will affect the starting sewing effect. If the thread end is too short, the thread will not be picked up at the start of sewing. If the thread end is too long, a "bird's nest" will be formed at the bottom of the sewn material, that is, the thread ends will stack together, affecting the product quality. The existing transmission structure is too long, resulting in insufficient force during the thread cutting process, affecting the thread cutting and prone to the appearance of "bird's nests". In addition, for the transmission of thread cutting and thread clamping, different motors are generally used for driving at present, which is prone to delays, resulting in the asynchronous thread cutting and thread clamping, increasing the probability of "bird's nests". Therefore, the current thread clamping and thread cutting mechanisms need to be improved. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned defects in the prior art, and provide a same-drive thread cutting and clamping mechanism for a sewing machine, which uses the same motor to drive to realize the synchronous and coordinated operation of thread cutting and thread clamping. Optimizing the transmission structure can effectively improve the stability of thread cutting and thread clamping, and effectively reduce the "bird's nest" phenomenon.

[0004] To achieve the above purpose, the present invention provides a same-drive thread cutting and clamping mechanism for a sewing machine, including a driving motor, a thread clamping cam, a thread cutting cam, a thread cutting drive rod group, a thread clamping drive rod group, a thread cutting assembly, and a thread clamping assembly;

[0005] The thread cutting cam and the thread clamping cam are respectively provided with an elliptical first cam groove and a second cam groove. The thread clamping cam and the thread cutting cam are both linked with the driving motor. The thread cutting cam and the thread clamping cam are arranged in a mirror image of each other, so that the directions of the first cam groove and the second cam groove are opposite;

[0006] A first roller is slidably arranged on the first cam groove. The thread cutting drive rod group is respectively connected with the first roller and the thread cutting assembly to realize the first roller cooperating with the thread cutting cam to drive the thread cutting assembly to perform thread cutting operation;

[0007] A second roller is slidably arranged on the second cam groove. The thread clamping drive rod group is respectively connected with the second roller and the thread clamping assembly to realize the second roller cooperating with the thread clamping cam to drive the thread cutting assembly to perform thread cutting operation.

[0008] Further, the thread cutting drive rod group includes a thread cutting connecting piece, a main thread cutting transmission shaft, and a moving knife connecting rod. The two ends of the main thread cutting transmission shaft are respectively linked with the thread cutting connecting piece and the moving knife connecting rod. The other end of the thread cutting connecting piece away from the main thread cutting transmission shaft forms a first connecting arm, and the first connecting arm is connected with the first roller. The first roller is inserted into the first cam groove to realize the movable connection between the first roller and the thread cutting cam. The moving knife connecting rod is connected with the thread cutting assembly.

[0009] Further, a first buffer spring is further included. One end of the first buffer spring is connected with a tension spring pin, and the tension spring pin is fixedly connected to the machine base of the sewing machine and is away from the main thread cutting transmission shaft. The other end of the first buffer spring is connected with the thread cutting connecting piece. By arranging the first buffer tension spring, the impact force generated by the transmission components can be absorbed during the operation of the thread cutting mechanism, significantly reducing the vibration and noise of the mechanism, improving the running stability, and at the same time playing a certain limiting role on the thread cutting connecting piece to prevent it from shaking under force and affecting the thread clamping effect.

[0010] Further, a thread cutting connecting rod is arranged between the main thread cutting transmission shaft and the moving knife connecting rod. A first shaft hole for sleeving the main thread cutting transmission shaft is arranged on the thread cutting connecting rod, and a second locking hole communicating with the first shaft hole is arranged on the side wing of the thread cutting connecting rod for cooperating with the locking of the main thread cutting transmission shaft. The other end of the thread cutting connecting rod away from the first shaft hole extends outwards to form a second connecting arm, and a third shaft hole for connecting with the moving knife connecting rod is arranged on the second connecting arm. The second connecting arm and the thread cutting connecting rod are arranged at 90°, realizing the conversion of the rotational force of the main thread cutting transmission shaft into a longitudinal pulling force. The thread cutting connecting rod adopts an integral extension design, realizing power transmission and direction conversion in a limited space, avoiding additional connecting parts, improving the overall rigidity of the mechanism and space utilization rate, and being applicable to the thread cutting mechanism layouts of different models of sewing machines. Through the first shaft hole tightly sleeving the main transmission shaft and combining with the locking structure of the second locking hole, the rigid connection between the thread cutting connecting rod and the main transmission shaft is ensured, preventing loosening or offset during the movement process, and improving the accuracy and reliability of power transmission. The design of the second locking hole allows for quick locking or unlocking through standard parts such as bolts and pins, simplifying the assembly process, facilitating later maintenance or replacement at the same time, and reducing the use cost. The setting of the second connecting arm and the third shaft hole forms a multi-point lever structure, effectively dispersing the driving force of the main transmission shaft, making the movement of the moving knife connecting rod more stable, reducing impact and vibration, and improving the smoothness of the thread cutting action.

[0011] Further, the thread cutting assembly includes a thread cutting thread clamping piece, a thread cutting movable knife, and a fixed knife. The thread cutting movable knife is arranged below the needle plate of the sewing machine through a provided thread cutting movable shaft, and the fixed knife is fixedly connected below the needle plate and cooperates with the thread cutting movable knife to cut the thread.

[0012] The movable thread cutting knife includes a thread cutting connection part, a fourth shaft hole for cooperating with the movable thread cutting shaft, and a movable knife thread cutting part. The fourth shaft hole is arranged at the middle position of the movable thread cutting knife. The thread cutting connection part and the movable knife thread cutting part are respectively the two end parts of the movable thread cutting knife. The thread cutting connection part is rotatably connected to the above-mentioned movable knife connecting rod. One end of the movable knife thread cutting part is a wire splitting end part, and this wire splitting end part is bent inwards, so that an arc-shaped wire splitting opening is formed between the wire splitting end part and the body of the movable thread cutting knife. The other end of the movable knife thread cutting part away from the wire splitting end part forms a wire guiding opening, and a movable knife cutting edge is arranged on the movable knife thread cutting part;

[0013] A fixed knife cutting edge is arranged on one side of the fixed knife. This fixed knife cutting edge is placed above the movable knife thread cutting part and is located on the rotation track of the movable thread cutting knife. The front end part of the thread cutting clamping piece is provided with an arc-shaped thread cutting clamping part;

[0014] The thread cutting clamping piece is arranged below the movable thread cutting knife and cooperates with the wire guiding opening to clamp the bobbin thread.

[0015] By accurately arranging the fourth shaft hole at the middle position of the movable thread cutting knife, an ideal lever fulcrum is formed, making the forces on the thread cutting connection part and the movable knife thread cutting part more balanced, and significantly improving the stability and accuracy of the thread cutting action; the movable knife thread cutting part forms a movable knife cutting edge, a wire splitting opening and a wire guiding opening before and after, and they cooperate with each other to realize the wire splitting and thread cutting functions as the movable knife thread cutting part rotates. The structure is simple, the thread cutting effect is good, and the bird's nest phenomenon can be effectively avoided.

[0016] Further, the clamping driving rod group includes a clamping movable connecting rod, a clamping main transmission shaft and a first clamping connecting rod. One end of the clamping movable connecting rod is connected to the second roller, and the other end of the clamping movable connecting rod is locked to the clamping main transmission shaft to realize linkage. A first buffer assembly is arranged between the clamping movable connecting rod and the clamping main transmission shaft. Both ends of the first clamping connecting rod are respectively connected to the clamping assembly and the clamping main transmission shaft.

[0017] Further, the first buffer assembly includes a clamping fixed connecting rod, a second buffer spring and a third buffer spring. The clamping fixed connecting rod is provided with a third connecting arm, a fourth connecting arm and a fifth connecting arm. A clamping connecting sleeve is fixedly connected to the third connecting arm. The clamping main transmission shaft is clamped on this clamping connecting sleeve and is linked with the clamping fixed connecting rod. One end of the clamping movable connecting rod is movably connected to the clamping connecting sleeve. The fourth connecting arm is adjacent to the other end of the clamping movable connecting rod and is connected through the second buffer spring. One end of the third buffer spring is connected to the fifth connecting arm, and the other end of the third buffer spring is connected to the sewing machine base. This assembly can ensure that the bobbin thread clamping piece can always clamp the face thread, and can play a buffering role when exceeding the range, avoiding motor overload.

[0018] Further, a wire clamping limiting groove is provided on the wire clamping movable connecting rod, and a limiting screw is connected to the wire clamping fixed connecting rod. The limiting screw is placed in the wire clamping limiting groove to limit the wire clamping movable connecting rod. The wire clamping limiting groove is an arc-shaped groove body. The rotation of the first movable connecting rod is restricted through the limiting groove to avoid overloading the motor due to exceeding the limit. The radian of the arc-shaped groove allows precise control of the swing angle of the movable connecting rod by rotating the position of the screw. At the same time, the contact line between the screw and the arc-shaped groove is a continuous curve. Compared with the point contact or short-side line contact of the straight groove, the pressure load can be dispersed, and the wear rate per unit area can be reduced.

[0019] Further, a second wire clamping connecting rod is also provided between the wire clamping main transmission shaft and the first wire clamping connecting rod. One end of the second wire clamping connecting rod is provided with a first connecting hole for sleeving the wire clamping main transmission shaft. The other end of the second wire clamping connecting rod is linked with the first wire clamping connecting rod through a provided screw. The second wire clamping connecting rod and the first wire clamping connecting rod are distributed at 90°. The second wire clamping connecting rod and the wire clamping main transmission shaft are sleeved through the first connecting hole to ensure the concentricity of power transmission, reduce torque loss and wear caused by eccentricity. The second wire clamping connecting rod and the first wire clamping connecting rod are vertically arranged, which can convert the rotational motion of the thread cutting main transmission shaft into the orthogonal direction motion of the first wire clamping connecting rod, enabling the first wire clamping connecting rod to pull the bottom thread clamping piece back and forth for clamping and releasing.

[0020] Further, the wire clamping assembly includes a bottom thread clamping piece and a wire clamping fixed block. The wire clamping fixed block is arranged on one side of the bottom thread clamping piece and cooperates with the bottom thread clamping piece to clamp the wire. The bottom thread clamping piece includes a wire clamping connecting portion, a wire clamping rotating hole, and a wire clamping clamping arm. A wire clamping rotating shaft is sleeved on the wire clamping rotating hole. The wire clamping rotating shaft is fixed to the sewing machine. The wire clamping clamping arm is linked with the first wire clamping connecting rod through a provided screw. The wire clamping clamping arm is an arc structure and matches the outer edge shape of the wire clamping fixed block. It can enable the wire clamping clamping arm to rotate around the wire clamping rotating shaft, and cooperate with the wire clamping fixed block to clamp the sewing thread.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The driving motor of the present invention uses a stepping motor as the power source, which can provide precise power output to ensure the accuracy of wire clamping and thread cutting. Moreover, by using a thread cutting cam and a wire clamping cam in linkage with the driving motor, synchronous rotation of the two cams can be achieved, and thus synchronous thread cutting and wire clamping can be realized. In particular, the thread cutting cam and the wire clamping cam adopt a reverse spatial arrangement, which can separate the arrangement positions of the thread cutting drive rod group and the wire clamping drive rod group without mutual interference, ensuring the stable operation of the whole.

[0023] 2. Thread cutting operation of the present invention: By using the cooperation of the first cam groove and the first roller, the thread cutting cam is driven to rotate by a stepper motor. The first roller is driven by the first cam groove to rotate the thread cutting connecting piece. The thread cutting connecting piece drives the thread cutting connecting rod to rotate through the main thread cutting transmission shaft. The thread cutting connecting rod pulls the thread cutting movable knife to rotate along the thread cutting movable shaft through the movable knife connecting rod, and cooperates with the fixed knife and the thread cutting thread clamping piece to cut the bobbin thread and the surface thread and clamp the bobbin thread. By adopting a stepper motor drive and an oval first cam groove design, digital precise control of the thread cutting timing and stroke is realized; at the same time, the oval first cam groove effectively converts the rotational motion into an ideal variable-speed linear motion, which can effectively improve the power transmission efficiency. The precise cooperation between the movable knife and the fixed knife ensures accurate and rapid cutting of the surface thread and the bobbin thread, ensures the flatness of the cut, can effectively reduce the occurrence of the bird's nest phenomenon, and improves the processing quality of the sewing machine.

[0024] 3. Thread clamping operation of the present invention: When the sewing machine needle bar rises to the set position after reaching the lowest point during the first sewing stitch (preset, the second or third stitch, etc. can be set), the sewing machine sends a signal to drive the stepper motor to drive the thread clamping cam to rotate clockwise. The roller in the thread clamping link assembly moves in the thread clamping cam groove. When the stepper motor rotates clockwise, the roller, the first movable link, the main transmission shaft and the second link rotate counterclockwise. At the same time, the second link pulls the first link to move backward, and the first link pulls the bobbin thread clamping piece to rotate clockwise until it contacts the bobbin thread fixing block to complete the thread clamping operation; the first movable link can rotate around the first fixed link group, and the rotation range is within the limit screw in the limit groove range of the first movable link. When not clamping the thread, the first movable link and the first fixed link are located at the maximum movable range position under the action of the first buffer spring. Since the limit groove is an arc structure, when the first movable link rotates, the convex part of the limit groove will squeeze the limit screw to drive the first fixed link to rotate accordingly. When the bobbin thread clamping piece contacts the bobbin thread fixing block, the limit screw has not reached the end of the limit groove. Therefore, the first movable link can still continue to rotate a certain angle around the first fixed link, which can ensure that the bobbin thread clamping piece and the bobbin thread fixing block can always clamp the surface thread, and can play a buffering role when exceeding the range, avoiding motor overload.

[0025] 4. The thread cutting drive rod group and the thread clamping drive rod group of the present invention are both provided with buffer components, which can protect each connecting rod and the motor, and avoid problems such as over-rotation and motor overload. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technology in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0027] Figure 1 It is a schematic structural diagram of a same-drive thread-cutting and thread-clamping mechanism of a sewing machine according to the present invention;

[0028] Figure 2 It is a schematic explosion diagram when the present invention is installed on a sewing machine base;

[0029] Figure 3 It is a schematic structural diagram of a thread-clamping cam and a thread-cutting cam of the present invention;

[0030] Figure 4 It is a schematic structural diagram of a drive motor, a thread-cutting cam, a thread-cutting drive rod group and a thread-cutting assembly of the present invention;

[0031] Figure 5 It is a schematic structural diagram of a main thread-cutting transmission shaft of the present invention;

[0032] Figure 6 It is a schematic structural diagram of a thread-cutting connecting piece of the present invention;

[0033] Figure 7 It is a schematic structural diagram of a moving knife connecting rod and a thread-cutting connecting rod of the present invention;

[0034] Figure 8 It is a schematic diagram of the assembly positions of a thread-cutting moving knife, a fixed knife and a thread-cutting and thread-clamping piece of the present invention;

[0035] Figure 9 It is a schematic diagram of the structure of a thread-cutting moving knife of the present invention;

[0036] Figure 10 It is a schematic structural diagram of a fixed knife of the present invention;

[0037] Figure 11 It is a schematic structural diagram of a thread-cutting and thread-clamping piece of the present invention;

[0038] Figure 12 It is a schematic diagram of the movement trajectories of each thread-dividing group of the present invention;

[0039] Figure 13 It is a schematic diagram after the thread division of the present invention is completed;

[0040] Figure 14 It is a schematic structural diagram of a drive motor, a thread-clamping cam, a thread-clamping drive rod group and a thread-clamping assembly of the present invention;

[0041] Figure 15 is Figure 14 Another perspective schematic diagram with the drive motor hidden;

[0042] Figure 16 It is an exploded schematic diagram of a thread-clamping drive rod group and a first buffer assembly of the present invention;

[0043] Figure 17 It is a schematic structural diagram of the thread clamping fixed connecting rod, connecting sleeve and main drive shaft for thread clamping of the present invention;

[0044] Figure 18 It is a schematic structural diagram of the bobbin thread clamping piece and the thread clamping fixed block of the present invention;

[0045] Figure 19 It is a schematic diagram of the running track when the present invention enters the thread clamping state;

[0046] Figure 20 It is an assembly schematic diagram of the present invention and the sewing machine base;

[0047] Figure 21 It is Figure 20 A direct view in the A direction in

[0048] In the figure, it includes:

[0049] 1. Driving motor; 11. Motor fixing base; 2. Thread clamping cam; 21. Second cam groove; 22. Second roller; 3. Thread cutting cam; 31. First cam groove; 32. Camshaft hole; 33. Motor shaft tightening hole; 34. First roller; 4. Thread cutting drive rod group; 41. Thread cutting connecting piece; 411. First annular mounting part; 412. First locking port; 413. First locking hole; 414. First connecting arm; 415. First roller connection hole; 416. First roller rotating shaft; 4161. Head; 4162. Shaft connecting part; 4163. Locking part; 42. Main thread cutting drive shaft; 421. Thread cutting main shaft bearing; 422. Clamping edge; 43. Moving knife connecting rod; 431. First connecting rod hole; 432. Second connecting rod hole; 433. Connecting screw; 44. Thread cutting connecting rod; 441. First shaft hole; 442. Second locking hole; 443. Second connecting arm; 4431. Reinforcing rib; 444. Third shaft hole; 45. First buffer spring; 451. Pull spring pin; 5. Thread clamping drive rod group; 51. Thread clamping movable connecting rod; 511. First mounting part; 512. Third connecting hole; 513. Connecting shaft; 514. Fifth connecting hole; 515. Shaft retaining ring; 516. Limiting groove; 5161. Protruding part; 517. First spring pressing arm; 52. Main thread clamping drive shaft; 521. Second flat surface; 522. Thread clamping main shaft bearing; 53. First buffer assembly; 531. Thread clamping fixed connecting rod; 5311. Third connecting arm; 5312. Fourth connecting arm; 5313. Fifth connecting arm; 5314. Fourth connecting hole; 53141. First flat inner wall; 5315. Second spring pressing arm; 532. Second buffer spring; 533. Third buffer spring; 534. Connecting sleeve; 5341. Sleeve shaft hole; 5342. Sleeve connecting part; 5343. Sleeve connecting protrusion; 53431. First flat surface; 5344. Sleeve locking hole; 535. Limiting screw; 54. Second thread clamping connecting rod; 541. First connecting hole; 55. First thread clamping connecting rod; 6. Thread cutting assembly; 61. Thread cutting and clamping piece; 611. Thread cutting clamping part; 612. Clamping guiding part; 62. Thread cutting movable knife; 621. Thread cutting movable shaft; 622. Thread cutting connecting part; 6221. Fifth shaft hole; 623. Fourth shaft hole; 624. Moving knife thread cutting part; 6241. Wire separating end; 6242. Wire separating opening; 6243. Wire guiding opening; 6244. Moving knife cutting edge; 625. Guiding part; 63. Fixed knife; 631. Fixed knife cutting edge; 632. Fixed knife connecting hole; 7. Thread clamping assembly; 71. Bottom thread clamping piece; 711. Clamping connecting part; 712. Clamping rotating hole; 713. Clamping holding arm; 714. Clamping rotating shaft; 72. Thread clamping fixed block; 8. Sewing machine base; 9. Needle plate; 91. Bottom thread; 92. Top thread. Specific embodiments

[0050] The following will clearly and completely describe the technology in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are one embodiment of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0051] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as described in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0052] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features.

[0053] Please refer to Figures 1 to 21 , the embodiments of the present invention provide a same-drive thread cutting and clamping mechanism for a sewing machine, including a drive motor 1, a thread clamping cam 2, a thread cutting cam 3, a thread cutting drive rod group 4, a thread clamping drive rod group 5, a thread cutting assembly 6, and a thread clamping assembly 7;

[0054] As Figure 3As shown in the figure, the thread cutting cam 3 and the thread clamping cam 2 are respectively provided with an oval first cam groove 31 and a second cam groove 21. The thread cutting cam 3 and the thread clamping cam 2 are both linked with the driving motor 1. Specifically, the thread cutting cam 3 and the thread clamping cam 2 have the same structure. A camshaft hole 32 for inserting the output shaft of the driving motor 1 is provided in the middle of the thread cutting cam 3 and the thread clamping cam 2. A motor shaft tightening hole 33 is opened on one side of the camshaft hole 32. After the output shaft of the driving motor 1 is inserted into the camshaft hole 32, the motor shaft tightening hole 33 is locked with screws / bolts, etc., so that the main shaft of the driving motor 1 can be linked with the thread cutting cam 3 and the thread clamping cam 2. The thread clamping cam 2 and the thread cutting cam 3 are arranged in a mirror image of each other, so that the directions of the first cam groove 31 and the second cam groove 21 are opposite. That is, in this embodiment, the surface of the thread clamping cam 2 provided with the first cam groove 31 faces downward, and the surface of the thread cutting cam 3 provided with the second cam groove 21 faces upward. The other end surfaces of the thread clamping cam 2 and the thread cutting cam 3 are close to each other, and then they are locked with the output shaft of the driving motor 1 through the motor shaft tightening holes 33 provided respectively and bolts, etc. Thus, the thread cutting drive rod group 4 and the thread clamping drive rod group 5 are respectively placed on both sides of the driving motor 1, and they can work without interference during operation, improving the smoothness of the equipment operation. It should be noted that the setting of this embodiment is only one of the assembly methods. In other embodiments, the setting directions and positions of the thread cutting cam 3 and the thread clamping cam 2 can be freely adjusted, as long as the thread cutting drive rod group 4 and the thread clamping drive rod group 5 can work normally;

[0055] A first roller 34 is slidably arranged on the first cam groove 31. The thread cutting drive rod group 4 is respectively connected with the first roller 34 and the thread cutting assembly 6, so that the first roller 34 cooperates with the thread cutting cam 3 to drive the thread cutting assembly 6 to perform thread cutting operation;

[0056] As Figure 4 shown in the figure, the thread cutting drive rod group 4 includes a thread cutting connecting piece 41, a thread cutting main transmission shaft 42 and a moving knife connecting rod 43. A thread cutting connecting rod 44 is arranged between the thread cutting main transmission shaft 42 and the moving knife connecting rod 43. The two ends of the thread cutting main transmission shaft 42 are respectively linked with the thread cutting connecting piece 41 and the moving knife connecting rod 43. The other end of the thread cutting connecting piece 41 away from the thread cutting main transmission shaft 42 is connected with the first roller 34. The first roller 34 is inserted into the first cam groove 31 and is movably connected with the thread cutting cam 3; Specifically, as Figure 4As shown, two main cutting spindles bearings 421 are sleeved on the main cutting spindle drive shaft 42. The two main cutting spindles bearings 421 are respectively sleeved on the upper and lower ends of the main cutting spindle drive shaft 42. The main cutting spindles bearings 421 are fixedly connected to the sewing machine base 8, realizing the vertical setting of the main cutting spindle drive shaft 42 without affecting the rotation of the main cutting spindle drive shaft 42. Moreover, a clamping edge 422 is arranged along the outer periphery of the main cutting spindles bearings 421. The clamping edge 422 can make the main cutting spindles bearings 421 be clamped with the outer side of the sewing machine base 8, making the connection of the main cutting spindles bearings 421 more stable. At the same time, the clamping edge 422 of the main cutting spindles bearings 421 arranged above can play a certain bearing role for the cutting link 44, and the clamping edge 422 of the main cutting spindles bearings 421 arranged below plays a limiting role for the cutting connector 41, so that the cutting connector 41 will not shake up and down, improving the stability of the kinetic energy conversion during rotation.

[0057] The lower end of the main cutting spindle drive shaft 42 is locked and linked with the cutting connector 41. The specific structure is as Figure 5 and Figure 6 shown. A first annular mounting portion 411 for wrapping the main cutting spindle drive shaft 42 is arranged on the cutting connector 41. A first locking opening 412 is opened on one side of the first annular mounting portion 411. A first locking hole 413 penetrating the first locking opening 412 is arranged on one side of the first annular mounting portion 411. During assembly, first insert the lower end of the main cutting spindle drive shaft 42 into the first locking opening 412, and then lock the first locking hole 413 through components such as screws so that the first annular mounting portion 411 can be tightly locked with the lower end of the main cutting spindle drive shaft 42. A first connecting arm 414 is formed at the other end of the cutting connector 41 away from the first annular mounting portion 411. A first roller connection hole 415 is arranged on the first connecting arm 414. A first roller rotating shaft 416 is arranged on the first roller connection hole 415. The first roller 34 is movably connected to the first roller rotating shaft 416. The first roller 34 is inserted into the first cam groove 31, so that the outer edge of the first roller 34 is attached to the inner wall of the first cam groove 31, enabling the first roller 34 to rotate as the cutting cam 3 rotates.

[0058] To buffer the wire cutting connector 41 and prevent the driving motor 1 from being overloaded, a first buffer spring 45 is further provided in this embodiment. One end of the first buffer spring 45 is connected with a draw spring pin 451. The draw spring pin 451 is fixedly connected to the sewing machine base 8 and is far away from the main wire cutting transmission shaft 42. The other end of the first buffer spring 45 is connected with the wire cutting connector 41. By providing the first buffer spring 45, the impact force generated by the transmission components can be absorbed during the wire cutting operation, significantly reducing the mechanism vibration and noise, improving the running stability. At the same time, it plays a certain limiting role on the wire cutting connector 41, preventing it from shaking under force and affecting the thread clamping effect. Preferably, the first buffer spring 45 can be connected to the wire cutting connector 41 through a second draw spring pin 451. The second draw spring pin 451 is arranged at the middle position of the wire cutting connector 41, so that the two ends of the wire cutting connector 41 are evenly stressed. And when the driving motor 1 rotates beyond the range, the first buffer spring 45 can play a buffering role to prevent the motor from being overloaded.

[0059] As Figure 7 shown, a first shaft hole 441 for sleeving the main wire cutting transmission shaft 42 is provided on the wire cutting connecting rod 44. A second locking hole 442 communicating with the first shaft hole 441 is opened on the flank of the wire cutting connecting rod 44 for cooperating with the locking of the main wire cutting transmission shaft 42. The main wire cutting transmission shaft 42 is tightly sleeved through the first shaft hole 441, and combined with the locking structure of the screw and the second locking hole 442, to ensure the rigid connection between the wire cutting connecting rod 44 and the main wire cutting transmission shaft 42, preventing looseness or deviation during the movement process, and improving the accuracy and reliability of power transmission. The other end of the wire cutting connecting rod 44 far away from the first shaft hole 441 extends outwards to form a second connecting arm 443. A third shaft hole 444 for connecting with the moving knife connecting rod 43 is provided on the second connecting arm 443. Specifically, first connecting holes 431 and second connecting holes 432 are respectively arranged at both ends of the moving knife connecting rod 43. The first connecting hole 431 is connected with the third shaft hole 444 through a connecting screw 433. The connecting screw 433 has the same structure as the first roller rotating shaft 416, and both include a head 4161, a shaft connecting part 4162 and a locking part 4163. The first connecting hole 431 is sleeved on the shaft connecting part 4162 of the connecting screw 433 to realize rotation, and the locking part is locked with the third shaft hole 444, which can be specifically a thread locking. Thus, the rotation between the moving knife connecting rod 43 and the main wire cutting transmission shaft 42 is realized. The second connecting arm 443 and the wire cutting connecting rod 44 are arranged at 90°, realizing the transformation of the rotational force of the main wire cutting transmission shaft 42 into a longitudinal pulling force.

[0060] To increase the structural rigidity of the second connecting arm 443, a reinforcing rib 4431 is provided on the second connecting arm 443. The setting of the reinforcing rib 4431 can effectively enhance the bending and torsion resistance of the wire cutting connecting rod 44, prevent deformation or fracture caused by alternating stress during high-frequency wire cutting actions, and extend the service life.

[0061] As shown Figure 8 in the figure, the thread cutting assembly 6 includes a thread cutting and clamping piece 61, a thread cutting moving knife 62 and a fixed knife 63. The thread cutting moving knife 62 is arranged below the needle plate 9 of the sewing machine through a provided thread cutting moving shaft 621. The fixed knife 63 is fixedly connected below the needle plate 9 and cooperates with the thread cutting moving knife 62 adjacent to cut the thread. The thread cutting moving knife 62 is arranged below the needle plate 9 of the sewing machine through a provided thread cutting moving shaft 621. Specifically, as shown Figure 9 in the figure, the thread cutting moving knife 62 includes a thread cutting connecting part 622, a fourth shaft hole 623 for cooperating with the thread cutting moving shaft 621 and a moving knife thread cutting part 624. The fourth shaft hole 623 is arranged at the middle position of the thread cutting moving knife 62. The thread cutting connecting part 622 and the moving knife thread cutting part 624 are respectively the two end parts of the thread cutting moving knife 62. A fifth shaft hole 6221 is arranged on the thread cutting connecting part 622. The fifth shaft hole 6221 is rotatably connected with the second connecting hole 432 of the moving knife connecting rod 43 through a moving shaft. One end of the moving knife thread cutting part 624 is a wire separating end part 6241. The wire separating end part 6241 is a sharp structure arranged obliquely, and the wire separating end part 6241 bends towards the inside of the thread cutting moving knife 62, so that an arc-shaped wire separating opening 6242 is formed between the wire separating end part 6241 and the body of the thread cutting moving knife 62. The other end of the moving knife thread cutting part 624 far from the wire separating end part 6241 forms a wire guiding opening 6243. A moving knife cutting edge 6244 is arranged on the moving knife thread cutting part 624. The thickness of the moving knife thread cutting part 624 gradually increases from both sides to the moving knife cutting edge 6244, so that a height difference is formed between the wire guiding opening 6243 and the moving knife cutting edge 6244. A flat wire guiding part is formed between the wire guiding opening 6243 and the moving knife cutting edge 6244. Through the design of the height difference between the wire guiding opening 6243 and the moving knife cutting edge 6244, a natural wire transition slope is formed to ensure that the sewing thread can be smoothly guided from the wire guiding opening 6243 to the cutting position, effectively preventing the wire from getting stuck or shifting during the thread cutting process. By adopting the thickness design that gradually increases from both sides of the wire guiding opening 6243 to the moving knife cutting edge 6244, a larger material cross-section is obtained at the edge part, significantly improving the bending strength and wear resistance of the cutting part and prolonging the service life of the tool.

[0062] As shown Figure 8 and Figure 10As shown, a fixed cutting edge 631 is provided on one side of the fixed knife 63. The fixed cutting edge 631 is placed above the moving knife thread cutting part 624 and is located on the projection of the rotation trajectory of the thread cutting moving knife 62. Specifically, the setting direction of the fixed cutting edge 631 is the same as that of the wire separating end part 6241 and is arranged opposite to the moving knife cutting edge 6244. The distance between the fixed cutting edge 631 and the moving knife cutting edge 6244 is smaller than the diameters of the bobbin thread 91 and the face thread 92, ensuring that the bobbin thread 91 and the face thread 92 can be completely cut. On the other side of the fixed knife 63 far from the fixed cutting edge 631, a fixed knife connection hole 632 is provided, and the fixed knife 63 is fixed below the needle plate 9 through the cooperation of the fixed knife connection hole 632 and a screw. Through the cooperation design of the upper and lower knives, a shearing principle similar to that of scissors is formed. The moving force of the moving knife is effectively received by the fixed knife 63, significantly improving the shearing efficiency, reducing energy consumption, and the fixed cutting edge 631 is accurately set above the moving knife thread cutting part 624 and is located on its rotation trajectory, ensuring that the moving knife cutting edge 6244 and the fixed cutting edge 631 meet at the best shearing position, realizing a clean and neat thread cutting action with a smooth incision and no burrs.

[0063] As Figure 8 and Figure 11 described, an arc-shaped thread cutting clamping part 611 is provided at the front end of the thread cutting and clamping piece 61. The thread cutting and clamping piece 61 is arranged below the thread cutting moving knife 62 and cooperates with the wire guiding port 6243 to clamp the bobbin thread 91. Specifically, the setting direction of the thread cutting clamping part 611 is the same as that of the wire separating end part 6241 and is arranged opposite to the wire guiding port 6243. The thread cutting clamping part 611 extends outward to form an inclined clamping wire guiding part 612. The setting of the clamping wire guiding part 612 can more accurately guide the ground wire to the cooperation of the thread cutting clamping part 611 and the wire guiding port 6243 to clamp the bobbin thread 91. By providing the arc-shaped thread cutting clamping part 611, a cooperative clamping mechanism is formed with the wire guiding port 6243 of the thread cutting moving knife 62, ensuring that the bobbin thread 91 maintains a stable tension during the thread cutting process, avoiding the retraction or loosening of the thread end, and significantly improving the thread cutting success rate.

[0064] A second roller 22 is slidably arranged on the second cam groove 21. The clamping wire driving rod group 5 is respectively connected to the second roller 22 and the clamping wire assembly 7, realizing that the second roller 22 cooperates with the clamping wire cam 2 to drive the thread cutting assembly 6 to perform thread cutting operations.

[0065] As Figure 1 , Figure 2 , Figure 14 , Figure 15 and Figure 16As shown, the thread clamping drive rod group 5 includes a thread clamping movable connecting rod 51, a thread clamping main transmission shaft 52, and a first thread clamping connecting rod 55. A first mounting portion 511 extends outward from the middle position of the thread clamping movable connecting rod 51. A third connecting hole 512 is provided on the first mounting portion 511. A connecting shaft 513 is connected to the third connecting hole 512. The end of the connecting shaft 513 is connected to the second roller 22. The second roller 22 is slidably disposed in the second cam groove 21. When the thread clamping cam 2 rotates, the roller can be driven to rotate along the second cam groove 21, realizing the action of the thread clamping cam 2 driving the thread clamping movable connecting rod 51 to rotate.

[0066] As Figure 17 , a first buffer assembly 53 is provided between the thread clamping movable connecting rod 51 and the thread clamping main transmission shaft 52. The first buffer assembly 53 is used to realize the linkage between the thread clamping movable connecting rod 51 and the thread clamping main transmission shaft 52. As Figures 14 to 17 shown, in this embodiment, the first buffer assembly 53 includes a thread clamping fixed connecting rod 531, a second buffer spring 532, and a third buffer spring 533. The thread clamping fixed connecting rod 531 is provided with a third connecting arm 5311, a fourth connecting arm 5312, and a fifth connecting arm 5313. A connecting sleeve 534 is fixedly connected to the third connecting arm 5311. The thread clamping main transmission shaft 52 is clamped on the connecting sleeve 534 to be linked with the thread clamping fixed connecting rod 531. Specifically, a fourth connecting hole 5314 is provided on the third connecting arm 5311. A first straight inner wall 53141 is provided on the inner wall of the fourth connecting hole 5314. The connecting sleeve 534 is provided with a sleeve shaft hole 5341 penetrating through the connecting sleeve 534. A sleeve connecting portion 5342 is provided at the lower end of the connecting sleeve 534. The sleeve connecting portion 5342 is provided with a sleeve connecting protrusion 5343 matching the fourth connecting hole 5314. A first flat surface 53431 matching the first straight inner wall 53141 is provided on the sleeve connecting protrusion 5343. During assembly, the sleeve connecting portion 5342 of the connecting sleeve 534 is directly inserted into the fourth connecting hole 5314, and the cooperation between the first flat surface 53431 and the first straight inner wall 7141 can realize the linkage between the two. A sleeve locking hole 5344 communicating with the sleeve shaft hole 5341 is provided on one side of the connecting sleeve 534. The lower end of the thread clamping main transmission shaft 52 is inserted into the sleeve shaft hole 5341, and the thread clamping main transmission shaft 52 is locked through bolts and other parts with the sleeve locking hole 5344. To increase the connection stability between the connecting sleeve 534 and the thread clamping main transmission shaft 52, a second flat surface 521 is provided at the lower end of the thread clamping main transmission shaft 52. During locking, the bolt can directly abut against the second flat surface 521 for locking, so that the locking is more firm.

[0067] One end of the wire clamping movable link 51 is provided with a fifth connection hole 514. The sleeve connection part 5342 is directly inserted into the fifth connection hole 514, so that the wire clamping movable link 51 can rotate around the sleeve connection part 5342 to realize the movable connection with the connection sleeve 534. Finally, the wire clamping movable link 51 is locked by the provided shaft retaining ring 515 to prevent the wire clamping movable link 51 from falling off.

[0068] A limiting groove 516 is arranged on the wire clamping movable link 51. The wire clamping fixed link 531 is connected with a limiting screw 535. The limiting screw 535 is placed in the limiting groove 516 to limit the wire clamping movable link 51. The limiting groove 516 is an arc groove body. Through the cooperation of the limiting groove 516 and the limiting screw 535, the wire clamping movable link 51 and the wire clamping fixed link 531 are linked, and then the rotation of the wire clamping main transmission shaft 52 is driven. Preferably, a convex part 5161 is arranged on the inner wall of one side of the limiting groove 516.

[0069] In addition, to further improve the buffering effect between the wire clamping movable link 51 and the wire clamping fixed link 531 and the protection of the second buffer spring 532, the fourth connecting arm 5312 is adjacent to the other end of the wire clamping movable link 51 and is connected by the second buffer spring 532. A first spring pressing arm 517 is arranged at the connection part of the wire clamping movable link 51 and the second buffer spring 532. A second spring pressing arm 5315 is arranged on the fourth connecting arm 5312. The first spring pressing arm 517 and the second spring pressing arm 5315 are stacked relative to each other at the axial center position of the second buffer spring 532, and the lengths of the first spring pressing arm 517 and the second spring pressing arm 5315 are the same. When the wire clamping movable link 51 rotates, the second buffer spring 532 is compressed, so that the first spring pressing arm 517 and the second spring pressing arm 5315 move relative to each other. Finally, the first spring pressing arm 517 and the second spring pressing arm 5315 will respectively abut against the side wings of the fourth connecting arm 5312 and the side wings of the wire clamping movable link 51, so that the wire clamping movable link 51 and the wire clamping fixed link 531 rotate synchronously and no longer compress the second buffer spring 532, thereby realizing the protection of the second buffer spring 532.

[0070] One end of the third buffer spring 533 is connected with the fifth connecting arm 5313, and the other end of the third buffer spring 533 is connected with the sewing machine base 8. The third buffer spring 533 plays a buffering role in the rotation of the wire clamping fixed link 531 to avoid damage to parts caused by overloading of rotation.

[0071] A wire clamping main transmission shaft bearing 522 is sleeved on the wire clamping main transmission shaft 52. The wire clamping main transmission shaft bearing 522 is fixedly connected to the sewing machine base 8 to realize the limitation of the wire clamping main transmission shaft 52. By fixing the wire clamping main transmission shaft bearing 522 on the sewing machine base 8, the wire clamping main transmission shaft 52 can only rotate, ensuring the stability of the operation of the bottom thread clamping piece 71.

[0072] Both ends of the first thread clamping link 55 are respectively connected to the bottom thread clamping piece 71 and the main thread clamping transmission shaft 52. A second thread clamping link 54 is also arranged between the main thread clamping transmission shaft 52 and the first thread clamping link 55. One end of the second thread clamping link 54 is provided with a first connection hole 541 for sleeving the main thread clamping transmission shaft 52. The other end of the second thread clamping link 54 is linked with the first thread clamping link 55 through a screw. The second thread clamping link 54 and the first thread clamping link 55 are distributed at 90°. Preferably, the second thread clamping link 54 is integrally in a semi-circular bending structure. In a limited space, the bending link can bypass obstacles, optimize the overall layout, improve the utilization rate of space, and at the same time, the geometric characteristics of the semi-circular bending structure can enhance the bending resistance ability, provide a stable force transmission to ensure the normal clamping and loosening of the bottom thread clamping piece 71.

[0073] As Figure 18 shown, the thread clamping assembly 7 includes a bottom thread clamping piece 71 and a thread clamping fixed block 72. The thread clamping fixed block 72 is arranged on one side of the bottom thread clamping piece 71 and cooperates with the bottom thread clamping piece 71 to clamp the thread. Specifically, as shown in the figure, the bottom thread clamping piece 71 includes a thread clamping connection part 711, a thread clamping rotation hole 712 and a thread clamping holding arm 713. A thread clamping rotation shaft 714 is sleeved on the thread clamping rotation hole 712. The thread clamping rotation shaft 714 is fixed to the needle plate 9. The thread clamping holding arm 713 is linked with the first thread clamping link 55 through a screw. The thread clamping holding arm 713 is in an arc structure and matches the outer edge shape of the thread clamping fixed block 72. It can enable the thread clamping holding arm 713 to rotate around the thread clamping rotation shaft 714 as the axis, and can cooperate with the thread clamping fixed block 72 to clamp the sewing thread. The front end of the thread clamping fixed block 72 is an arc surface. Setting it as an arc surface can better closely abut against the clamping part, making the clamping effect on the sewing thread better.

[0074] Brief description of the working principle of the present invention:

[0075] As Figure 2 Figure 20 and Figure 21 shown, during assembly, the thread cutting assembly 6 and the thread clamping assembly 7 are respectively placed on both sides of the driving motor 1. The driving motor 1 drives the thread cutting cam 3 and the thread clamping cam 2 to rotate synchronously, so that thread cutting and thread clamping can be carried out synchronously without delay. In particular, the thread cutting cam 3 and the thread clamping cam 2 are arranged in a mirror image. Therefore, when the driving motor 1 is started, the rotation directions of the thread cutting cam 3 and the thread clamping cam 2 are opposite to each other, and alternating synchronous operations of thread cutting and thread clamping can be realized, improving the operation efficiency and accuracy. The specific operation process is as follows:

[0076] Working principle of thread cutting: As Figure 12 and Figure 13As shown, in practical applications, the drive motor 1 is fixed to the lower side of the lower machine base through the motor fixing base 11. The tension spring pin 451 is fixedly connected to the sewing machine base 8 to form a force application point. The fixed cutter 63 and the thread cutting clamping piece 61 surround the needle insertion opening of the needle plate 9. The thread cutting movable cutter 62 is placed between the fixed cutter 63 and the thread cutting clamping piece 61 for cooperation. During operation, when receiving the start signal from the electronic control device of the sewing machine, as shown in the figure, the drive motor 1 starts and drives the thread cutting cam 3 to rotate counterclockwise. The roller moves in the groove of the thread cutting cam 3, thereby driving the thread cutting connecting piece 41 and the thread cutting connecting rod 44 to move clockwise. The thread cutting connecting rod 44 pushes the movable cutter connecting rod 43 to move to the left. The movable cutter connecting rod 43 drives the thread cutting movable cutter 62 to rotate clockwise. As the thread cutting movable cutter 62 moves, the thread separating end 6241 passes through between the bobbin thread 91 and the upper thread 92, causing the upper thread 92 to be placed on the thread separating opening 6242 until the thread cutting movable cutter 62 moves to the preset limit distance as shown in the figure. At this time, the thread separating action is completed.

[0077] After the thread separating action is completed, the drive motor 1 rotates clockwise in reverse. Through the above intermediate transmission rods, the thread cutting movable cutter 62 rotates counterclockwise. When the thread cutting movable cutter 62 rotates, it drives the upper thread 92 and the bobbin thread 91 to move towards the fixed cutter 63 through the wire guiding opening 6243 of the thread cutting movable cutter 62. When the cutting edge of the thread cutting movable cutter 62 contacts the fixed cutting edge 631 of the fixed cutter 63, the upper thread 92 and the bobbin thread 91 are cut. The bobbin thread 91 will fall onto the wire guiding part. The drive motor 1 continues to rotate in reverse, driving the thread cutting movable cutter 62 to continue moving until it contacts the thread cutting clamping part 611 in contact with the thread cutting clamping piece 61 and clamps the bobbin thread 91, completing the thread cutting action.

[0078] The working principle of clamping the thread: In the assembly of the present invention, as shown in the figure and the figure, the drive motor 1 can be installed on the side wing of the sewing machine base 8 through a motor fixing base 11. The bobbin thread clamping piece 71 and the bobbin thread 91 fixing block are directly installed below the needle plate 9 of the sewing machine base 8. The two clamping main drive shaft bearings 522 provided at the upper and lower ends of the clamping main drive shaft 52 are respectively clamped on the sewing machine base 8. The other end of the third buffer spring 533 is fixedly connected to the sewing machine base 8 through screws, etc. During operation, as shown in the figure, when the sewing machine starts sewing the first stitch (preset, the second stitch or the third stitch, etc. can be set) and the needle bar of the sewing machine rises to the set position after reaching the lowest point, the sewing machine sends a signal to drive the drive motor 1 to drive the clamping cam 2 to rotate clockwise. The roller in the clamping link assembly moves in the groove of the clamping cam 2. When the drive motor 1 rotates clockwise, the roller, the clamping movable link 51, the clamping main drive shaft 52, and the second clamping link 54 rotate counterclockwise. At the same time, the second clamping link 54 pulls the first clamping link 55 to move backward, and the first clamping link 55 pulls the bobbin thread clamping piece 71 to rotate clockwise until it contacts the bobbin thread 91 fixing block, completing the clamping action.

[0079] When sewing to the second stitch (preset, the third stitch or the fourth stitch, etc. can be set), when the needle bar returns to the set position after rising to the lowest point, the sewing machine sends a signal again, causing the drive motor 1 to reverse counterclockwise and return to its original position. Through the above intermediate transmission parts, the bottom thread clamping piece 71 rotates counterclockwise to the initial position, completing the whole action.

[0080] Brief description of the working principle of the thread clamping movable link 51 and the thread clamping fixed link 531:

[0081] As Figure 19 , the thread clamping movable link 51 can rotate around the thread clamping fixed link 531 group, and the rotation range is within the limit groove 516 of the thread clamping movable link 51 by the limit screw 535. When not clamping the thread, the thread clamping movable link 51 and the thread clamping fixed link 531 are located at the maximum movement range position under the action of the second buffer spring 532. Since the limit groove 516 is an arc structure, when the thread clamping movable link 51 rotates, the protrusion 5161 of the limit groove 516 will squeeze the limit screw 535 to drive the thread clamping fixed link 531 to rotate accordingly. When the bottom thread clamping piece 71 contacts the bottom thread 91 fixing block, the limit screw 535 has not reached the end of the limit groove 516. Therefore, the first movable rod can still continue to rotate a certain angle around the thread clamping fixed link 531. Thus, it can ensure that the bottom thread clamping piece 71 and the bottom thread 91 fixing block can always clamp the surface thread 92, and can play a buffering role when exceeding the range, avoiding motor overload.

[0082] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A same-drive thread cutting and clamping mechanism for a sewing machine, characterized in that, It includes a drive motor (1), a thread clamping cam (2), a thread cutting cam (3), a thread cutting drive rod group (4), a thread clamping drive rod group (5), a thread cutting assembly (6), and a thread clamping assembly (7); The thread cutting cam (3) and the thread clamping cam (2) are respectively provided with an oval first cam groove (31) and a second cam groove (21). The thread clamping cam (2) and the thread cutting cam (3) are both linked with the drive motor (1). The thread cutting cam (3) and the thread clamping cam (2) are arranged in a mirror image of each other, so that the directions of the first cam groove (31) and the second cam groove (21) are opposite to each other; A first roller (34) is slidably arranged on the first cam groove (31). The thread cutting drive rod group (4) is respectively connected with the first roller (34) and the thread cutting assembly (6) to realize that the first roller (34) cooperates with the thread cutting cam (3) to drive the thread cutting assembly (6) to perform a thread cutting operation; A second roller (22) is slidably arranged on the second cam groove (21). The thread clamping drive rod group (5) is respectively connected with the second roller (22) and the thread clamping assembly (7) to realize that the second roller (22) cooperates with the thread clamping cam (2) to drive the thread cutting assembly (6) to perform a thread cutting operation.

2. The same-drive thread cutting and clamping mechanism of a sewing machine according to claim 1, characterized in that, The thread cutting drive rod group (4) includes a thread cutting connecting piece (41), a thread cutting main transmission shaft (42), and a moving knife connecting rod (43). The two ends of the thread cutting main transmission shaft (42) are respectively linked with the thread cutting connecting piece (41) and the moving knife connecting rod (43). The other end of the thread cutting connecting piece (41) far from the thread cutting main transmission shaft (42) forms a first connecting arm (414). The first connecting arm (414) is connected with the first roller (34). The first roller (34) is inserted into the first cam groove (31) to realize the movable connection between the first roller (34) and the thread cutting cam (3). The moving knife connecting rod (43) is connected with the thread cutting assembly (6).

3. The same-drive thread cutting and clamping mechanism of a sewing machine according to claim 2, characterized in that, It further includes a first buffer spring (45). One end of the first buffer spring (45) is connected with a pull spring pin (451). The pull spring pin (451) is fixedly connected to the machine base of the sewing machine and is far from the thread cutting main transmission shaft (42). The other end of the first buffer spring (45) is connected with the thread cutting connecting piece (41).

4. The same-drive thread cutting and clamping mechanism of a sewing machine according to claim 3, characterized in that, A thread cutting connecting rod (44) is arranged between the thread cutting main transmission shaft (42) and the moving knife connecting rod (43). A first shaft hole (441) for sleeving the thread cutting main transmission shaft (42) is arranged on the thread cutting connecting rod (44). A second locking hole (442) communicating with the first shaft hole (441) is arranged on the flank of the thread cutting connecting rod (44) for cooperating with the locking of the thread cutting main transmission shaft (42); The other end of the thread cutting connecting rod (44) far from the first shaft hole (441) extends outwards to form a second connecting arm (443). A third shaft hole (444) connected with the moving knife connecting rod (43) is arranged on the second connecting arm (443). The second connecting arm (443) and the thread cutting connecting rod (44) are arranged at 90°, realizing the conversion of the rotational force of the thread cutting main transmission shaft (42) into a longitudinal pulling force.

5. The same-drive thread cutting and clamping mechanism of a sewing machine according to claim 4, characterized in that, The wire cutting assembly (6) includes a wire cutting and clamping piece (61), a wire cutting moving knife (62), and a fixed knife (63). The wire cutting moving knife (62) is arranged below the needle plate (9) of the sewing machine through a provided wire cutting moving shaft (621). The fixed knife (63) is fixedly connected below the needle plate (9) and cooperates with the wire cutting moving knife (62) adjacent to cut the wire. The wire cutting moving knife (62) includes a wire cutting connecting part (622), a fourth shaft hole (623) for cooperating with the wire cutting moving shaft (621), and a moving knife wire cutting part (624). The fourth shaft hole (623) is arranged at the middle position of the wire cutting moving knife (62). The wire cutting connecting part (622) and the moving knife wire cutting part (624) are respectively the two end parts of the wire cutting moving knife (62). The wire cutting connecting part (622) is rotatably connected with the above-mentioned moving knife connecting rod (43). One end of the moving knife wire cutting part (624) is a wire separating end part (6241), and this wire separating end part (6241) is bent inwards, so that an arc-shaped wire separating opening (6242) is formed between the wire separating end part (6241) and the body of the wire cutting moving knife (62). The other end of the moving knife wire cutting part (624) away from the wire separating end part (6241) forms a wire guiding opening (6243). A moving knife cutting edge (6244) is provided on the moving knife wire cutting part (624). A fixed knife cutting edge (631) is arranged on one side of the fixed knife (63). This fixed knife cutting edge (631) is placed above the moving knife wire cutting part (624) and is located on the rotation track of the wire cutting moving knife (62). The front end of the wire cutting and clamping piece (61) is provided with an arc-shaped wire cutting clamping part (611). The wire cutting and clamping piece (61) is arranged below the wire cutting moving knife (62) and cooperates with the wire guiding opening (6243) to clamp the bobbin thread (91).

6. The same-drive thread cutting and clamping mechanism of a sewing machine according to claim 1, characterized in that, The clamping driving rod group (5) includes a clamping moving connecting rod (51), a clamping main transmission shaft (52), and a first clamping connecting rod (55). One end of the clamping moving connecting rod (51) is connected with the second roller (22). The other end of the clamping moving connecting rod (51) is locked with the clamping main transmission shaft (52) to achieve linkage. A first buffer assembly (53) is arranged between the clamping moving connecting rod (51) and the clamping main transmission shaft (52). The two ends of the first clamping connecting rod (55) are respectively connected with the clamping assembly (7) and the clamping main transmission shaft (52).

7. The same-drive thread cutting and clamping mechanism of a sewing machine according to claim 6, characterized in that, The first buffer assembly (53) includes a wire clamping fixed link (531), a second buffer spring (532), and a third buffer spring (533). The wire clamping fixed link (531) is provided with a third connecting arm (5311), a fourth connecting arm (5312), and a fifth connecting arm (5313). A wire clamping connecting sleeve (534) is fixedly connected to the third connecting arm (5311). The wire clamping main transmission shaft (52) is clamped on the wire clamping connecting sleeve (534) and is linked with the wire clamping fixed link (531). One end of the wire clamping movable link (51) is movably connected to the wire clamping connecting sleeve (534). The fourth connecting arm (5312) is adjacent to the other end of the wire clamping movable link (51) and is connected by the second buffer spring (532). One end of the third buffer spring (533) is connected to the fifth connecting arm (5313), and the other end of the third buffer spring (533) is connected to the sewing machine base (8).

8. A same-drive thread cutting and clamping mechanism for a sewing machine according to claim 7, characterized in that, A wire clamping limit groove (516) is provided on the wire clamping movable link (51). The wire clamping fixed link (531) is connected with a limit screw (535). The limit screw (535) is placed in the wire clamping limit groove (516) to limit the wire clamping movable link (51). The wire clamping limit groove (516) is an arc groove body.

9. The same-drive thread cutting and clamping mechanism of a sewing machine according to claim 8, characterized in that A second wire clamping link (54) is further provided between the wire clamping main transmission shaft (52) and the first wire clamping link (55). One end of the second wire clamping link (54) is provided with a first connection hole (541) for sleeving the wire clamping main transmission shaft (52). The other end of the second wire clamping link (54) is linked with the first wire clamping link (55) through a provided screw. The second wire clamping link (54) and the first wire clamping link (55) are distributed at 90°.

10. A same-drive thread cutting and clamping mechanism of a sewing machine according to claim 7, characterized in that, The wire clamping assembly (7) includes a bobbin thread clamping piece (71) and a wire clamping fixed block (72). The wire clamping fixed block (72) is arranged on one side of the bobbin thread clamping piece (71) and cooperates with the bobbin thread clamping piece (71) to clamp the thread. The bobbin thread clamping piece (71) includes a wire clamping connection part (711), a wire clamping rotation hole (712), and a wire clamping clamping arm (713). A wire clamping rotation shaft (714) is sleeved on the wire clamping rotation hole (712). The wire clamping rotation shaft (714) is fixed to the sewing machine. The wire clamping clamping arm (713) is linked with the first wire clamping link (55) through a provided screw. The wire clamping clamping arm (713) is an arc structure and matches the outer edge shape of the wire clamping fixed block (72).

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