Thread trimming mechanism and sewing machine

Abstract

The utility model relates to the technical field of sewing machines, and provides a thread trimming mechanism and a sewing machine. The thread trimming mechanism comprises a fixed cutter, a movable cutter assembly and a driving device. The movable cutter assembly is in transmission connection with the driving device so as to drive the movable cutter assembly to rotate relative to the fixed cutter through the driving device, and the thread trimming angle between the movable cutter assembly and the fixed cutter is adjusted; the driving device comprises a driving part and a first transmission assembly, the first transmission assembly comprises a guiding part, a first transmission part and a second transmission part, the first transmission part is in transmission connection with the driving part and the second transmission part, the second transmission part is connected with the movable cutter assembly, and the first transmission part is configured to move along the guiding part under driving of the driving part; and the second transmission part is driven to drive the movable cutter assembly to rotate, so that the thread trimming angle of the thread trimming mechanism is changed.

Description

TECHNICAL FIELD

[0001] The present application relates to the sewing machine technical field, especially to a thread cutting mechanism and a sewing machine. BACKGROUND

[0002] The sewing machine is a mechanical device that uses a needle and a sewing thread to form a stitch on a material such as fabric or leather, thereby sewing the material together. The sewing machine is generally provided with a thread cutting mechanism, which includes a driving device, a fixed knife, and a movable knife. The fixed knife is usually fixed on the machine body, and the movable knife can usually move relative to the machine body under the driving of the driving device, thereby cooperating with the fixed knife to cut the thread.

[0003] In the prior art, the driving modes of the driving device mainly include electromagnetic driving and cylinder driving. Electromagnetic driving is to make the electromagnet generate magnetic force by electrification, drive the movable knife to descend, and cooperate with the fixed knife to cut the thread. Cylinder driving is to drive the cylinder to move linearly by air pressure, drive the movable knife to descend, and cooperate with the fixed knife to cut the thread.

[0004] The thread cutting action of the electromagnetic driving is usually linear, lacks control of the intermediate position, and limits the adjustment of the angle. The mechanical stroke of the cylinder driving is fixed during use, so the thread cutting angle of the movable knife and the fixed knife is fixed. Both of the above-mentioned two ways cannot control the thread cutting angle, and are prone to failure when facing sewing threads with different toughness, and the thread cutting efficiency is low. CONTENT OF THE UTILITY MODEL

[0005] The present application provides a thread cutting mechanism and a sewing machine to solve the technical problem that the automatic thread cutting mechanism of the sewing machine cannot control the thread cutting angle.

[0006] The present application provides the following technical solutions to solve the above technical problems:

[0007] In a first aspect, the present application provides a thread cutting mechanism, which includes a fixed knife, a movable knife assembly, and a driving device.

[0008] The movable knife assembly is in transmission connection with the driving device, so as to drive the movable knife assembly to rotate relative to the fixed knife by the driving device, and adjust the thread cutting angle between the movable knife assembly and the fixed knife.

[0009] The driving device includes a driving member and a first transmission assembly. The first transmission assembly includes a guide portion, a first transmission member, and a second transmission member. The first transmission member and the second transmission member are in transmission connection with the driving member and the second transmission member. The second transmission member is connected with the movable knife assembly. The first transmission member is configured to move along the guide portion under the driving of the driving member, so as to drive the second transmission member to rotate the movable knife assembly.

[0010] In a possible implementation, the guide portion comprises a sleeve, the first transmission member is at least partially inserted into the sleeve, a connecting groove is formed on the sleeve, and a transmission portion is arranged in the connecting groove to connect the first transmission member and the second transmission member through the transmission portion.

[0011] In a possible implementation, the transmission portion comprises a plurality of first transmission teeth arranged on the first transmission member and a plurality of second transmission teeth arranged on the second transmission member, and the first transmission teeth and the second transmission teeth are in meshing relationship.

[0012] In a possible implementation, the guide portion further comprises an elastic member, and the elastic member is located between the first transmission member and the sleeve away from the driving member.

[0013] In a possible implementation, the guide portion further comprises a fixing head, the fixing head is located at an end of the sleeve away from the driving member, the fixing head at least partially extends into the sleeve, the elastic member is located between the fixing head and the first transmission member, and the fixing head is configured to change the length of extension into the sleeve to adjust the position of the elastic member.

[0014] In a possible implementation, the driving device further comprises a second transmission assembly, the second transmission assembly is in transmission connection with the driving member and the first transmission assembly, and the second transmission assembly is configured to drive the first transmission assembly to move under the driving of the driving member.

[0015] In a possible implementation, the driving member is a control motor, the second transmission assembly comprises a cam and a third transmission member, the cam is connected with an output shaft of the control motor, the part of the first transmission member extending out of the sleeve is connected with the third transmission member, the third transmission member is in abutment with the cam, and the cam is configured to drive the third transmission member to move along the extension direction of the guide portion under the driving of the control motor.

[0016] In a possible implementation, the third transmission member comprises a crank and a rotating ball sleeve, the rotating ball sleeve is in rotational connection with the crank, and the rotating ball sleeve is in abutment with the cam.

[0017] In a second aspect, an embodiment of the present application provides a sewing machine, comprising the thread cutting mechanism, a machine body, a workbench, a moving knife assembly mounting seat and a knife set mounting seat, the workbench is used for placing sewing materials, the driving member, the guide portion and the workbench are arranged on the machine body, the moving knife assembly is arranged on the moving knife assembly mounting seat, the moving knife assembly mounting seat is connected to the machine body through the knife set mounting seat, and the fixed knife is fixed on the workbench.

[0018] In a possible implementation, the sewing machine comprises a control unit and a detection device; the detection device and the thread trimming mechanism are electrically connected to the control unit.

[0019] The worktable plate comprises a detection area, the detection device is configured to detect the sewing material information on the detection area of the worktable plate and send the detected sewing material information to the control unit, and the control unit is configured to:

[0020] determine whether the sewing material exists on the detection area of the worktable plate according to the sewing material information;

[0021] if the sewing material exists, the control unit determines whether the thread trimming needle value is equal to the preset thread trimming needle value after the sewing material passes through the detection device;

[0022] if the thread trimming needle value is equal to the preset thread trimming needle value, the control unit controls the thread trimming mechanism to trim the thread.

[0023] The thread trimming mechanism and the sewing machine provided in the application comprise a movable cutter assembly, a fixed cutter and a driving device, the movable cutter assembly is in transmission connection with the driving device, and the driving part and the second transmission part of the driving device are in transmission connection with the first transmission part. During use, the first transmission part is driven to move along the guide part by the driving part, the second transmission part is driven to rotate by the first transmission part, and the movable cutter assembly is driven to rotate by the second transmission part, so that the movable cutter assembly can be rotated to any angle and cooperate with the fixed cutter to trim the thread. Therefore, the thread trimming mechanism can adjust the thread trimming angle according to the actual situation, and the thread trimming efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] The drawings incorporated into the specification and forming a part thereof show embodiments consistent with the application and, together with the specification, serve to explain the principles of the application.

[0025] Figure 1 a perspective view of the sewing machine provided in the embodiments of the application;

[0026] Figure 2 an exploded view of the thread trimming mechanism provided in the embodiments of the application;

[0027] Figure 3 a structural schematic view of the thread trimming mechanism provided in the embodiments of the application;

[0028] Figure 4 a structural schematic view of the cam in the thread trimming mechanism provided in the embodiments of the application.

[0029] REFERENCE NUMERALS:

[0030] 100 - fixed cutter

[0031] 200 - blade assembly;

[0032] 310 - driving member; 320 - output shaft; 330 - first transmission assembly; 331 - guide portion; 3311 - sleeve; 3312 - elastic member; 3313 - fixed head; 3314 - connecting groove; 332 - first transmission member; 333 - second transmission member; 340 - second transmission assembly; 341 - cam; 342 - third transmission member; 3421 - crank; 3422 - rotating ball sleeve; 350 - transmission portion; 351 - first transmission tooth; 352 - second transmission tooth;

[0033] 400 - machine body; 410 - worktable plate;

[0034] 500 - control unit;

[0035] 600 - detection device;

[0036] a - shearing line stroke angle;

[0037] b - lowest holding angle of shearing line blade assembly.

[0038] The specific embodiments of the application have been shown and described in the above drawings, which will be described in more detail hereinafter. These drawings and the written description are not intended to restrict the scope of the concept of the application in any way, but to illustrate the concept of the application for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0039] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The description of the exemplary embodiments is intended to apply to various alternative embodiments of the application. It is to be understood that features illustrated or described as part of one embodiment can be provided with one or more of the other embodiments as well. Variations to these embodiments can become apparent to those of ordinary skill in the art once the concepts of the application are understood. The following detailed description is, therefore, not to be taken in a limiting sense, as the scope of the application is defined by the appended claims and equivalents thereof.

[0040] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" 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 convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0041] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0042] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication or interaction relationship between two elements, unless otherwise specifically 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 description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0044] In the related art, the existing automatic thread cutting mechanism of the sewing machine is mainly divided into two types of electromagnetic automatic thread cutting and cylinder automatic thread cutting according to the driving mode. The electromagnetic automatic thread cutting drives the moving knife to move for thread cutting operation by generating a magnetic field through the energization of the electromagnet; the cylinder automatic thread cutting drives the piston to move for thread cutting by driving the piston through compressed air. Both methods cannot adjust the thread cutting angle, and the thread cutting noise is large.

[0045] In order to overcome the above problems, the present application provides a thread cutting mechanism, which adjusts the thread cutting angle by driving the moving knife assembly through the driving device. The driving device of the thread cutting mechanism includes a driving member, a first transmission member and a second transmission member, the driving member and the second transmission member are in transmission connection with the first transmission member, the driving member drives the first transmission member to move, so that the first transmission member drives the second transmission member to rotate when moving, the second transmission member rotates to drive the moving knife assembly to rotate synchronously, so that the position of the moving knife assembly relative to the fixed knife changes, the thread cutting angle is adjusted, and the thread cutting is completed, thereby solving the problem that the thread cutting angle cannot be adjusted in the prior art.

[0046] The structure, function and implementation process of the thread trimming mechanism provided by the embodiment will be illustrated below with reference to the drawings.

[0047] Figure 1 is an example of the overall structure of the sewing machine provided by the example embodiment, Figure 2 is an example of the structure of the thread trimming mechanism provided by the example embodiment.

[0048] Please refer to Figure 1 , the sewing machine comprises a machine body 400, the machine body 400 is provided with a workbench plate 410, the workbench plate 410 is used to place a workpiece to be sewn, when the sewing machine is in a working state, the workpiece is placed on the workbench plate 410 for sewing, after sewing is completed, the workpiece is removed from the workbench plate 410, and the thread trimming mechanism of the sewing machine trims the thread; the machine body further comprises a moving knife assembly mounting seat and a knife set mounting seat, the moving knife assembly mounting seat is arranged on the machine body 400 through the knife set mounting seat, and the moving knife assembly mounting seat is used to mount a moving knife assembly 200.

[0049] Please refer to Figure 2 , the thread trimming mechanism comprises a fixed knife 100, a moving knife assembly 200 and a driving device. The moving knife assembly 200 comprises a moving knife and a moving knife shaft, the moving knife is connected to one end of the moving knife shaft, the moving knife assembly 200 is arranged on the moving knife assembly mounting seat, the moving knife assembly mounting seat is arranged on the machine body 400 through the knife set mounting seat, the fixed knife 100 is arranged on the workbench plate 410, the fixed knife 100 and the moving knife are matched and can engage to complete thread trimming. The driving device comprises a driving piece 310 and a first transmission assembly 330, the first transmission assembly 330 comprises a guide portion 331, a first transmission piece 332 and a second transmission piece 333, and the driving piece 310 and the guide portion 331 are arranged on the machine body 400.

[0050] It should be noted that the moving knife can be detachably connected to the moving knife shaft, for example, the moving knife is fixed on the moving knife shaft by using bolts and nuts, or the moving knife and the moving knife shaft are connected by buckles, splines or other methods; the moving knife can also be connected to the moving knife shaft by welding, hot pressing and other non-detachable methods, which are not limited in the embodiment.

[0051] It should be noted that the driving piece 310 and the guide portion 331 can be installed on the machine body 400 by screws, clamps and other methods.

[0052] It should be noted that for the driving piece 310, it can be a combination of some common devices and mechanical components, as long as it can drive the first transmission piece 332 to move along the guide portion 331, which is not limited in the embodiment.

[0053] Exemplarily, the driving member 310 can be a lifting motor, which drives the first transmission member 332 to move along the guide portion 331, drives the second transmission member 333 to rotate, drives the movable knife shaft to rotate, and drives the movable knife to rotate. According to the characteristics of different sewing threads, the movable knife rotates to a corresponding angle and engages with the fixed knife 100 to complete the thread cutting action.

[0054] The thread cutting mechanism of the embodiment has the first transmission member 332 of the driving device in transmission connection with the driving member 310 and the second transmission member 333. The driving member 310 drives the first transmission member 332 to move along the guide portion 331, drives the second transmission member 333 to rotate, drives the movable knife shaft to rotate, and drives the movable knife to rotate, so that the movable knife can rotate to an arbitrary angle and engage with the fixed knife 100 to complete thread cutting. Therefore, the thread cutting mechanism can adjust the thread cutting angle according to actual conditions and improve the thread cutting efficiency.

[0055] The guide portion 331 is used to guide the movement direction of the first transmission member 332 and provide an accurate movement direction for the first transmission member 332, so as to prevent the first transmission member 332 from tilting and deviating from the movement track during movement and improve the stability and safety of the equipment.

[0056] In some embodiments, the guide portion 331 can be a combination of a guide rail and a sliding block. The sliding block is in sliding connection with the guide rail, and the first transmission member 332 is connected with the sliding block. When the driving member 310 drives the first transmission member 332, the first transmission member 332 moves along the guide rail through the sliding block. The guide rail provides an accurate path for the first transmission member 332, ensures the smooth movement of the first transmission member 332, and reduces vibration and friction by using the sliding block in cooperation with the guide rail. This not only improves the work efficiency, but also helps to prolong the service life of the equipment and reduce the maintenance and replacement costs.

[0057] In some embodiments, please continue to refer to Figure 1 and Figure 2 The guide portion 331 includes a sleeve 3311, the first transmission member 332 is at least partially inserted in the sleeve 3311, the sleeve 3311 is provided with a connecting groove 3314, the connecting groove 3314 is provided with a transmission portion 350, and the first transmission member 332 and the second transmission member 333 are connected through the transmission portion 350.

[0058] Exemplarily, the transmission portion 350 can be a connecting rod, and the second transmission member 333 can be a crank. The crank is arranged at the end of the movable knife shaft away from the movable knife. The first transmission member 332 moves linearly in the sleeve 3311, the linear movement is transmitted to the connecting rod, the connecting rod drives the crank to rotate, the movable knife shaft rotates, the angle of the movable knife adjusting engagement with the fixed knife 100 is adjusted, and the thread cutting action is completed.

[0059] Exemplarily, please refer toFigure 2 The transmission part 350 comprises a first transmission tooth 351 arranged on the first transmission member 332 and a second transmission tooth 352 arranged on the second transmission member 333. The first transmission member 332 moves linearly, and the first transmission tooth 351 and the second transmission tooth 352 are engaged to drive the second transmission member 333 to rotate, and the second transmission member 333 drives the movable cutter shaft to rotate, so that the movable cutter adjusts the angle of engagement with the fixed cutter 100 to complete the line cutting action.

[0060] For example, the first transmission member 332 can be a transmission shaft, and the first transmission tooth 351 is arranged on the transmission shaft. The second transmission member 333 can be a gear, and the teeth of the gear are the second transmission teeth 352. The first transmission tooth 351 on the transmission shaft is engaged with the second transmission tooth 352. The transmission shaft moves linearly, and the first transmission tooth 351 and the second transmission tooth 352 are engaged to drive the gear to rotate. The gear drives the movable cutter shaft to rotate, so that the movable cutter adjusts the angle of engagement with the fixed cutter 100 to complete the line cutting action. Through gear transmission, the energy loss is small, and the transmission efficiency is high.

[0061] It can be understood that the above examples are only illustrative of the transmission part 350, but not limiting. The transmission part 350 can be a combination of common devices or mechanical components in the prior art, as long as the movement of the first transmission member 332 can be transmitted to the second transmission member 333 to make the second transmission member 333 rotate.

[0062] In some embodiments, referring to Figure 2 The guide part 331 further comprises an elastic member 3312. The elastic member 3312 is located between the first transmission member 332 and the sleeve 3311.

[0063] For example, the elastic member 3312 can be a spring. The sleeve 3311 and the end of the first transmission member 332 away from the driving member 310 are provided with grooves, and the spring is arranged in the grooves.

[0064] For example, the elastic member 3312 can be a spring. The sleeve 3311 and the end of the first transmission member 332 away from the driving member 310 are provided with mounting seats, and the spring is arranged on the mounting seats.

[0065] For example, the elastic member 3312 can be a spring. The sleeve 3311 and the end of the first transmission member 332 away from the driving member 310 are provided with mounting seats, and the spring is arranged on the mounting seats.

[0066] When the driving member 332 drives the first transmission member 332 to move along the sleeve 3311, the elastic member 3312 is compressed, and when the first transmission member 332 returns to the original position, the elastic member 3312 gradually recovers. By using the elastic member 3312, it can be ensured that the first transmission member 332 is always in contact with the driving member 310.

[0067] Please refer to Figure 2 In the embodiment of the application, the guide part 331 can further include a fixed head 3313, which is arranged at one end of the sleeve 3311 away from the driving member 310 and extends at least partially into the sleeve 3311. The elastic member 3312 is located between the fixed head 3313 and the first transmission member 332.

[0068] The length of the fixed head 3313 extending into the sleeve 3311 can be changed to adjust the pre-tightening force of the elastic member 3312.

[0069] For example, the fixed head 3313 can be a pressure regulating screw, which is connected to the sleeve by threads and connected to one end of the elastic member 3312. When the pressure regulating screw is rotated clockwise, the length of the pressure regulating screw extending into the sleeve 3311 increases, and the pre-tightening force of the elastic member 3312 increases, thereby increasing the shearing force of the moving blade. When the pressure regulating screw is rotated counterclockwise, the length of the pressure regulating screw extending into the sleeve 3311 decreases, and the pre-tightening force of the elastic member 3312 decreases, thereby decreasing the shearing force of the moving blade. The pressure regulating screw adjusts the compression force of the elastic member 3312 by changing the position of the screw, thereby controlling the size of the shearing force of the moving blade. This structure is simple and has a small sound of cutting wire.

[0070] In some embodiments, the driving device further includes a second transmission assembly 340, which is in transmission connection with the driving member 310 and the first transmission assembly 330. The driving member 310 drives the second transmission assembly 340, and the second transmission assembly 340 drives the first transmission assembly 330 to move. The second transmission assembly 340 can be selected from mechanisms such as connecting rods and cams.

[0071] For example, the driving member 310 is a control motor, the output shaft 320 of the control motor is connected to one end of a connecting rod, and the first transmission member 332 is connected to the other end of the connecting rod. The output shaft 320 of the control motor drives the connecting rod to rotate, and the first transmission member 332 is driven by the connecting rod to move along the sleeve 3311 in a reciprocating linear motion. The first transmission member 332 and the second transmission member 333 are engaged by the first transmission teeth 351 and the second transmission teeth 352. The first transmission member 332 drives the second transmission member 333 to rotate, and the second transmission member 333 drives the moving blade to rotate through the moving blade shaft. The moving blade rotates to a corresponding angle and engages with the fixed blade 100 to complete the wire cutting action.

[0072] In some embodiments, please refer to Figure 2 , Figure 3And Figure 4 The second transmission assembly 340 comprises a cam 341 and a third transmission member 342. The cam 341 is arranged on the output shaft 320 of the control motor, for example, the cam 341 can be locked on the output shaft 320 by screws, or connected to the output shaft 320 by a key groove and the like. The third transmission member 342 is in transmission connection with the cam 341 and the part of the first transmission member 332 extending out of the sleeve 3311. The control motor drives the cam 341, the cam 341 pushes the third transmission member 342, and the third transmission member 342 pushes the first transmission member 332 to move along the guide part 331.

[0073] Please refer to Figure 4 The cam 341 comprises a shearing stroke angle a and a minimum holding angle b of the shearing knife assembly. In the range of the shearing stroke angle a, the engagement point is set, and in the use process, the engagement point is set at different positions according to different characteristics of the sewing thread. The movable knife and the fixed knife 100 engage at the engagement point to complete the shearing action. The minimum holding angle b of the shearing knife assembly is the limit angle of the rotation of the movable knife. In the range of the minimum holding angle b of the shearing knife assembly, the movable knife maintains the lowest angle reached by rotation. At this time, if the movable knife and the fixed knife 100 are still not engaged, the cam 341 needs to be reinstalled.

[0074] The third transmission member 342 can be a crank 3421, which is locked on the part of the first transmission member 332 extending out of the sleeve 3311 by screws. Under the action of the elastic member 3312, the crank 3421 is always in contact with the cam 341. The motor shaft drives the cam 341 to rotate, the cam 341 pushes the crank 3421, and the crank 3421 drives the first transmission member 332 to move along the guide part 331. By using the crank 3421, the motion can be smoothly transmitted, the impact and vibration caused by the shape change of the cam 341 can be reduced, the wear of the first transmission member 332 can be reduced, and thus the stability and durability can be improved.

[0075] In the embodiment of the application, the third transmission member 342 further comprises a rotating ball sleeve 3422, which has a through hole and is in rotational connection with the crank 3421 by locking screws or fixing pins and the like. The rotating ball sleeve 3422 can rotate radially, and is always in contact with the cam 341 under the pressure action of the elastic member 3312. The rotating ball sleeve 3422 can transmit motion and force in different angles and directions, and can also absorb and buffer vibration and impact to protect other components from damage.

[0076] In summary, the embodiment of the application provides a thread cutting mechanism, the driving member 310 of the thread cutting mechanism can be a control motor, the cam 341 is installed on the output shaft 320 of the control motor, the cam 341 is in contact with the rotating ball sleeve 3422, the rotating ball sleeve 3422 is installed on the crank 3421, the crank 3421 is installed on the part of the transmission shaft extending out of the sleeve 3311, the end of the sleeve 3311 away from the driving member 310 is provided with a pressure adjusting screw, the spring is installed between the end of the transmission shaft away from the driving member 310 and the pressure adjusting screw, the transmission shaft is in mesh with the gear through the first transmission gear 351, the gear is installed on the moving blade shaft, and the moving blade shaft is provided with a moving blade at the other end.

[0077] The output shaft 320 of the control motor drives the cam 341 to rotate, the cam 341 pushes the crank 3421 to move through the rotating ball sleeve 3422, the crank 3421 pushes the transmission shaft, and the transmission shaft moves linearly along the sleeve 3311; in the connecting groove 3314, the first transmission gear 351 on the transmission shaft is in mesh with the gear, the gear is driven to rotate, the gear drives the moving blade shaft to rotate, the moving blade shaft drives the moving blade to start rotating, within the thread cutting stroke angle a, the moving blade and the fixed blade 100 are in mesh at the set meshing point, the thread cutting action starts, after the thread cutting action is completed, the output shaft 320 of the control motor starts to rotate in the reverse direction, and the moving blade returns to the initial position.

[0078] If the moving blade and the fixed blade 100 are not in mesh at the set meshing point, the output shaft 320 of the control motor continues to drive the cam 341 to rotate, the rotation angle of the cam 341 is increased, the moving blade continues to rotate, and the meshing is completed. The lowest holding angle b of the thread cutting blade assembly is the limit angle of the rotation of the moving blade, the moving blade maintains the limit position reached within the range, if the moving blade and the fixed blade 100 are still not in mesh at the lowest holding angle b of the thread cutting blade assembly, it is necessary to check the installation error and re-install the cam 341.

[0079] If it is necessary to increase the shearing force, the pressure adjusting screw arranged on the sleeve 3311 is rotated, the length of the pressure adjusting screw extending into the sleeve 3311 is increased, the spring is compressed, and the shearing force is increased.

[0080] According to different characteristics of the sewing thread, the output shaft 320 of the control motor drives the cam 341 to rotate different angles, different meshing points are set within the thread cutting stroke angle a of the cam 341, and the thread cutting angle is controlled. In addition, the rotation speed of the output shaft 320 of the control motor can be adjusted, the thread cutting speed is adjusted, and the working efficiency is improved.

[0081] The embodiment of the application further provides a sewing machine, which comprises the thread trimming mechanism, a machine body 400, a worktable plate 410, a movable cutter assembly mounting seat and a cutter set mounting seat, the worktable plate 410 is used for placing a sewing material, the driving member 310, the guide part 331 and the worktable plate 410 are all arranged on the machine body 400, the movable cutter assembly 200 is arranged on the movable cutter assembly mounting seat, the movable cutter assembly mounting seat is connected to the machine body 400 through the cutter set mounting seat, and the fixed cutter 100 is fixed on the worktable plate 410.

[0082] The embodiment of the application further provides a sewing machine, which further comprises a control unit 500 and a detection device 600, the thread trimming mechanism and the detection device 600 are electrically connected with the control unit 500. The worktable plate 410 is provided with a detection area, the detection device 600 detects whether the detection area of the worktable plate 410 has the sewing material, and sends a detection result to the control unit 500; the control unit 500 judges whether the detection area of the worktable plate 410 has the sewing material according to the detection result, and if the sewing material exists, judges whether a thread trimming needle value is equal to a preset thread trimming needle value when the sewing material passes through the detection device 600; and if the thread trimming needle value is equal to the preset thread trimming needle value, the control unit 500 controls the thread trimming mechanism to trim the thread.

[0083] The detection device 600 comprises a transmitting sensor and a receiving sensor, the receiving sensor is arranged on the detection area of the worktable plate 410, and the transmitting sensor is arranged on the machine body 400 and corresponds to the receiving sensor. The transmitting sensor transmits a signal, the receiving sensor receives the signal, and the receiving sensor transmits the received signal to the control unit 500.

[0084] It should be noted that the signal transmitted by the transmitting sensor can be an optical signal, an ultrasonic signal, an infrared signal or the like; the receiving sensor can receive a reflection or shielding condition of light, or a reflection wave condition of ultrasonic waves, or a reflection or absorption characteristic condition of infrared light, etc.

[0085] It should be noted that the control unit 500 can be a programmable control system, which can control the engagement amount of the movable cutter and the fixed cutter 100, so as to improve the thread trimming precision of the sewing machine and improve the work efficiency.

[0086] Finally, it should be noted that: other embodiments of the application will be easily conceived by those skilled in the art after considering the specification and practicing the application disclosed herein. The application aims to cover any variations, uses or adaptations of the application, which follow the general principles of the application and include common knowledge or conventional technical means in the art that are not disclosed by the application, and is not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the application is only limited by the appended claims.

Claims

1. A thread trimming mechanism, characterized in that: It comprises a fixed knife (100), a movable knife assembly (200) and a driving device; The movable knife assembly (200) is in transmission connection with the driving device, so that the movable knife assembly (200) is driven by the driving device to rotate relative to the fixed knife (100), thereby adjusting the thread cutting angle between the movable knife assembly (200) and the fixed knife (100); The driving device includes a driving member (310) and a first transmission assembly (330), wherein the first transmission assembly (330) includes a guide portion (331), a first transmission member (332) and a second transmission member (333), wherein the first transmission member (332) is in transmission connection with the driving member (310) and the second transmission member (333), and the second transmission member (333) is connected to the movable knife assembly (200), and the first transmission member (332) is configured to move along the guide portion (331) under the drive of the driving member (310) to drive the second transmission member (333) to drive the movable knife assembly (200) to rotate.

2. The thread trimming mechanism according to claim 1, characterized in that: The guide portion (331) includes a sleeve (3311), the first transmission member (332) is at least partially inserted into the sleeve (3311), a connecting groove (3314) is provided on the sleeve (3311), and a transmission portion (350) is provided in the connecting groove (3314) to connect the first transmission member (332) and the second transmission member (333) through the transmission portion (350).

3. The thread trimming mechanism according to claim 2, characterized in that: The transmission part (350) comprises a plurality of first transmission teeth (351) provided on the first transmission member (332), and a plurality of second transmission teeth (352) provided on the second transmission member (333), wherein the first transmission teeth (351) and the second transmission teeth (352) are meshed with each other.

4. The thread trimming mechanism according to claim 2, characterized in that: The guide portion (331) further includes an elastic member (3312), and the elastic member (3312) is located between an end of the first transmission member (332) facing away from the driving member (310) and the sleeve (3311).

5. The thread trimming mechanism according to claim 4, characterized in that: The guide portion (331) further includes a fixed head (3313), the fixed head (3313) being located at an end of the sleeve (3311) facing away from the driving member (310), the fixed head (3313) at least partially extending into the sleeve (3311), the elastic member (3312) being located between the fixed head (3313) and the first transmission member (332), and the fixed head (3313) being configured to change the length of the fixed head extending into the sleeve (3311) so as to adjust the position of the elastic member (3312).

6. The thread trimming mechanism according to claim 2, characterized in that: The driving device further includes a second transmission assembly (340), the second transmission assembly (340) being in transmission connection with both the driving member (310) and the first transmission assembly (330), and the second transmission assembly (340) being configured to drive the first transmission assembly (330) to move under the drive of the driving member (310).

7. The thread trimming mechanism according to claim 6, characterized in that: The driving member (310) is a control motor. The second transmission assembly (340) includes a cam (341) and a third transmission member (342). The cam (341) is connected to the output shaft (320) of the control motor. The portion of the first transmission member (332) extending outside the sleeve (3311) is connected to the third transmission member (342). The third transmission member (342) abuts against the cam (341). The cam (341) is configured to, under the drive of the control motor, push the third transmission member (342) to move along the extension direction of the guide portion (331).

8. The thread trimming mechanism according to claim 7, characterized in that: The third transmission member (342) comprises a crank (3421) and a rotating ball sleeve (3422), wherein the rotating ball sleeve (3422) is rotationally connected to the crank (3421), and the rotating ball sleeve (3422) abuts against the cam (341).

9. A sewing machine, characterized in that: The invention comprises the thread cutting mechanism according to any one of claims 1 to 8, a machine body (400), a work table (410), a movable knife assembly mounting seat (210) and a knife group mounting seat (220), wherein the work table (410) is used for placing sewing materials, the driving member (310), the guide portion (331) and the work table (410) are all arranged on the machine body (400), the movable knife assembly (200) is arranged on the movable knife assembly mounting seat, the movable knife assembly mounting seat is connected to the machine body (400) through the knife group mounting seat, and the fixed knife (100) is fixed on the work table (410).

10. The sewing machine according to claim 9, characterized in that It comprises a control unit (500) and a detection device (600); the detection device (600) and the thread cutting mechanism are both electrically connected to the control unit (500); The workbench (410) includes a detection area, and the detection device (600) is used to detect sewing material information on the detection area of ​​the workbench (410), and send the detected sewing material information to the control unit (500). The control unit (500) is configured to: judging whether the sewing material exists on the detection area of ​​the workbench (410) according to the sewing material information; If the sewing material exists, determining whether the trimming needle value is equal to the preset trimming needle value; If the thread trimming needle value is equal to the preset thread trimming needle value, the control unit (500) controls the thread trimming mechanism to trim the thread.

Images