Thread trimming device and sewing machine

Abstract

The utility model provides a thread trimming device and a sewing machine. The thread trimming device comprises a fixed knife and a fixed knife, the clamping piece is arranged below the fixed cutter, and a clamping gap is formed between the clamping piece and the fixed cutter; the movable cutter is provided with a first groove used for clamping a to-be-sheared line, and the driving motor is in driving connection with the movable cutter to drive the movable cutter to swing, so that the movable cutter swings to the position where at least part of the first groove is attached to the fixed cutter to complete line shearing; and in the swinging process of the movable cutter, the movable cutter drives the line to penetrate into the clamping gap, so that part of the cut line is clamped between the clamping piece and the movable cutter. The sewing machine solves the problem that the sewing efficiency of a sewing machine in the prior art is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of sewing machines, in particular to a thread trimming device and a sewing machine. Background Art

[0002] A sewing machine is a machine that uses one or more sewing threads to form one or more stitches on the sewing material, so that one or more layers of sewing material are interwoven or sewn together; during the production process, the bobbin thread is set in the rotary hook of the sewing machine, and the fabric is sewn by moving the upper thread to intersect with the lower thread. When sewing the last stitch, the upper thread and the lower thread will be intertwined under the needle plate. At this time, one end of the upper thread and the lower thread are connected to the fabric, the other end of the upper thread is connected to the sewing needle, and the other end of the lower thread is connected to the rotary hook. The interwoven upper thread and lower thread need to be cut by a thread cutting device.

[0003] Most thread trimming devices cut the upper thread and the lower thread through the cooperation of a movable knife and a fixed knife. After the cutting is completed, the sewing needle pulls out the thread end of the upper thread, while the thread end of the lower thread near the bobbin end will fall over due to lack of support, which may easily cause the upper thread to fail to combine quickly with the lower thread next time, resulting in a decrease in the sewing efficiency of the sewing machine. Utility Model Content

[0004] The main purpose of the utility model is to provide a thread trimming device and a sewing machine to solve the problem of reduced sewing efficiency of the sewing machine in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the utility model, there is provided a wire cutting device, comprising: a fixed knife; a clamping member, which is arranged below the fixed knife and forms a clamping gap with the fixed knife; a movable knife and a driving motor, the movable knife having a first groove for clamping the wire to be cut, and the driving motor is connected to the movable knife to drive the movable knife to swing, so as to complete the wire cutting by swinging the movable knife to a position where at least a part of the first groove fits the fixed knife; wherein, during the swinging process of the movable knife, the movable knife drives the wire to pass through the clamping gap, so that the part of the wire after cutting is clamped between the clamping member and the movable knife.

[0006] Furthermore, the clamping member includes a connecting portion, the connecting portion is fitted with the fixed knife, a first connecting hole is provided on the connecting portion, a second connecting hole is provided on the fixed knife, and fasteners are inserted into the first connecting hole and the second connecting hole to fasten the connecting portion to the fixed knife.

[0007] Furthermore, the clamping member also includes a clamping portion, the clamping portion includes a first clamping section and a second clamping section, two ends of the first clamping section are respectively connected to the second clamping section and the connecting portion, the extension direction of the second clamping section is parallel to the extension direction of the fixed knife, the extension direction of the first clamping section is perpendicular to the extension direction of the second clamping section, and a clamping gap is formed between the second clamping section and the fixed knife along the extension direction of the first clamping section.

[0008] Furthermore, the movable knife includes a first end face and a second end face that are arranged opposite to each other, and a first groove is arranged on the first end face, so that after the movable knife drives the line to pass through the clamping gap, both sides of the line respectively abut against the second end face and the second clamping section.

[0009] Furthermore, along the extension direction of the first groove, the first groove has a closed end and a free end that are relatively arranged, so that the movable knife is swung to a position where the closed end fits the fixed knife to complete the thread cutting; wherein, along the direction from the free end to the closed end, the distance between two adjacent groove walls of the first groove gradually decreases.

[0010] Furthermore, the thread trimming device also includes a transmission component, the drive motor is drivingly connected to the transmission component, and the transmission component is drivingly connected to the movable knife, so that the drive motor drives the movable knife to swing through the transmission component.

[0011] Furthermore, the transmission component includes a first transmission crank and a transmission rod. The first transmission crank is connected to the output shaft of the driving motor. The first transmission crank is hinged to one end of the transmission rod. The other end of the transmission rod is connected to the moving knife for transmission, so that the driving motor drives the transmission rod to reciprocate in a preset direction by driving the first transmission crank to rotate, so that the transmission rod drives the moving knife to swing.

[0012] Furthermore, the transmission component also includes a second transmission crank and a third transmission crank, the two ends of the second transmission crank are respectively connected to one end of the third transmission crank and the transmission rod, and the other end of the third transmission crank is connected to the moving knife, so that the transmission rod drives the second transmission crank to rotate, and the second transmission crank drives the third transmission crank and the moving knife to swing.

[0013] Furthermore, the wire trimming device also includes a base and a connecting plate, the connecting plate is connected to the base, the connecting plate cover is arranged above the drive motor and connected to the drive motor, a through hole is opened on the connecting plate, and the output shaft of the drive motor is passed through the through hole to be connected to the first transmission crank.

[0014] According to another aspect of the utility model, a sewing machine is provided, comprising the above-mentioned thread trimming device.

[0015] By applying the technical solution of the utility model, the thread trimming device of the utility model includes a fixed knife, a clamping member, a driving motor and a movable knife. The clamping member and the fixed knife form a clamping gap. The movable knife has a first groove for clamping the line to be cut. The driving motor drives the movable knife to swing to a position where at least a portion of the first groove fits the fixed knife to complete the thread cutting. During the swinging of the movable knife, the movable knife drives the line to pass through the clamping gap, so that the part of the line after cutting is clamped between the clamping member and the movable knife, so that the part of the line cut no longer shakes, and is smoothly combined with the surface thread, thereby ensuring the smooth progress of the sewing, thereby solving the problem of reduced sewing efficiency of the sewing machine in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0017] Figure 1 A schematic structural diagram of an embodiment of a thread trimming device according to the utility model is shown;

[0018] Figure 2 A front schematic diagram showing the structure of a movable knife, a fixed knife and a clamping member of a thread trimming device according to the utility model;

[0019] Figure 3 A schematic back view of the structure of the movable knife, the fixed knife and the clamping member of the thread trimming device according to the utility model is shown;

[0020] Figure 4 A side schematic diagram showing the structure of a movable knife, a fixed knife and a clamping member of a thread trimming device according to the utility model;

[0021] Figure 5 A schematic structural diagram of a clamping member of a thread trimming device according to the utility model is shown;

[0022] Figure 6 A schematic structural diagram of a movable knife of a thread trimming device according to the utility model is shown;

[0023] Figure 7 The schematic diagram of the structure of the transmission component, the movable knife, the fixed knife and the clamping member of the thread trimming device according to the utility model is shown.

[0024] The above drawings include the following reference numerals:

[0025] 10. Fixed knife; 20. Clamping member; 11. Clamping gap; 17. Blade; 30. Moving knife; 33. First groove; 39. Thread hooking part; 391. Thread blocking part; 21. Connecting part; 6. First connecting hole; 22. Clamping part; 221. First clamping section; 222. Second clamping section; 31. First end face; 32. Second end face; 331. Closed end; 332. Free end; 50. Driving motor; 61. First transmission crank; 62. Transmission rod; 63. Second transmission crank; 64. Third transmission crank; 70. Base; 71. Connecting plate; 80. Needle and thread board; 81. Thread passing hole. DETAILED DESCRIPTION

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0028] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0029] Please refer to Figures 1 to 7The utility model provides a wire cutting device, comprising: a fixed knife 10; a clamping member 20, which is arranged below the fixed knife 10 and forms a clamping gap 11 with the fixed knife 10; a movable knife 30 and a driving motor 50, wherein the movable knife 30 has a first groove 33 for clamping the wire to be cut, and the driving motor 50 is drivingly connected to the movable knife 30 to drive the movable knife 30 to swing, so as to complete the wire cutting by swinging the movable knife 30 to a position where at least a part of the first groove 33 is in contact with the fixed knife 10; wherein, during the swinging process of the movable knife 30, the movable knife 30 drives the wire to pass through the clamping gap 11, so that the part of the wire after cutting is clamped between the clamping member 20 and the movable knife 30.

[0030] like Figures 2 to 4 As shown, the thread trimming device of the utility model includes a fixed knife 10, a clamping member 20, a driving motor 50 and a movable knife 30. The clamping member 20 and the fixed knife 10 form a clamping gap 11. The movable knife 30 has a first groove 33 for clamping the line to be cut. The driving motor 50 drives the movable knife 30 to swing to a position where at least a portion of the first groove 33 fits with the fixed knife 10 to complete the thread trimming. During the swinging process of the movable knife 30, the movable knife 30 drives the line to pass through the clamping gap 11, so that the part of the line after cutting is clamped between the clamping member 20 and the movable knife 30, so that the part of the line cut no longer shakes, and is smoothly combined with the surface thread, thereby ensuring the smooth progress of the sewing, thereby solving the problem of reduced sewing efficiency of the sewing machine in the prior art.

[0031] Specifically, the lines to be cut include the bottom line and the top line. After the lines are cut, the thread end of the top line close to the sewing needle is pulled out, and the thread end of the bottom line close to the shuttle core end is clamped between the clamping member 20 and the movable knife 30 and will no longer fall over, so that the next top line can be quickly combined with the bottom line and the stitching is completed smoothly, which helps to improve the sewing efficiency of the sewing machine.

[0032] Specifically, the thread trimming device also includes a needle and thread plate 80 and a rotary shuttle (not shown in the figure). The needle and thread plate 80 is arranged above the fixed knife 10 and the movable knife 30, and the rotary shuttle is arranged below the movable knife 30, the fixed knife 10 and the clamping member 20. The needle and thread plate 80 has a thread passing hole 81. When sewing to the last stitch, since the cloth is above the needle and thread plate 80, the bottom line passes through the thread passing hole 81, and the end of the bottom line connected to the cloth is above the thread passing hole 81, and the end of the bottom line connected to the rotary shuttle is below the movable knife 30, the fixed knife 10 and the clamping member 20.

[0033] In the prior art, a sewing machine uses a sewing needle and two threads to complete sewing, one surface thread is inserted into the needle tip of the sewing needle, and the other bottom thread is hidden in the thread shuttle; when the machine rotates, the sewing needle carries the surface thread led out of the thread ball through the sewing material, and when the sewing needle drops to the lowest position, the sewing needle carries the surface thread and starts to rise upward from the original needle insertion position, and the sewing needle starts to be squeezed by the sewing thread as it rises with the surface thread. Due to the different friction coefficients among the needle, thread and material, the friction coefficient between the thread and the material is larger, so although the needle rises, the surface thread remains in the original position and does not move, so a thread loop is generated under the sewing needle plate hole, and this thread loop can just be hooked by the thread shuttle mouth that is being driven to rotate, and the thread loop is continuously enlarged, so that the thread is wrapped around the bobbin case and the bobbin hidden in the thread shuttle, and the surface thread and the bottom thread are intertwined. When the above actions are completed, the thread take-up rod rises sharply to shrink the thread loop, so that the surface thread and the bottom thread are intertwined in the middle of the sewing material.

[0034] When implementing it, Figure 6 As shown, the movable knife 30 also includes a thread hooking portion 39 and a thread blocking portion 391. When the thread cutting starts, the movable knife 30 swings so that the thread hooking portion 39 hooks the thread loop formed by the surface thread. At this time, the bottom line remains stationary, and the thread loop formed by the surface thread is gradually enlarged by the thread hooking portion 39, so that one side of the thread loop is blocked by the thread blocking portion 391, and the other side of the thread loop gradually slides to the first groove 33. Then the movable knife 30 starts to swing in the opposite direction, so that the bottom line enters the first groove 33. Then the movable knife 30 moves with the bottom line and the surface thread. When the movable knife 30 enters the clamping gap 11, the bottom line and the surface thread are blocked by the fixed knife and are gradually pressed into the first groove 33 by the fixed knife 10. At the same time, the bottom line connected to the rotary shuttle is blocked by the clamping member 20 and is gradually pressed between the movable knife 30 and the clamping member 20. Then when the movable knife 30 continues to swing to the position where at least part of the first groove 33 is in contact with the fixed knife 10, the thread cutting is completed.

[0035] In this embodiment, if Figure 5 As shown, the clamping member 20 includes a connecting portion 21, which is fitted with the fixed knife 10, a first connecting hole 6 is provided on the connecting portion 21, and a second connecting hole is provided on the fixed knife 10. Fasteners are inserted into the first connecting hole 6 and the second connecting hole to fasten the connecting portion 21 to the fixed knife 10.

[0036] Specifically, the connecting portion 21 is used to connect the fixed knife 10 and the clamping member 20, and is passed through the first connecting hole 6 and the second connecting hole by a fastener, thereby ensuring the connection reliability between the connecting portion 21 and the fixed knife 10, wherein the fastener is a bolt, and the fixed knife 10 is also connected to the needle and thread plate 80 by a bolt.

[0037] In this embodiment, if Figure 5As shown, the clamping member 20 also includes a clamping portion 22, and the clamping portion 22 includes a first clamping section 221 and a second clamping section 222. The two ends of the first clamping section 221 are respectively connected to the second clamping section 222 and the connecting portion 21, and the extension direction of the second clamping section 222 is parallel to the extension direction of the fixed knife 10. The extension direction of the first clamping section 221 is perpendicular to the extension direction of the second clamping section 222, and a clamping gap is formed between the second clamping section 222 and the fixed knife 10 along the extension direction of the first clamping section 221.

[0038] Specifically, the first clamping section 221 is used to connect the second clamping section 222 and the connecting portion 21, and the second clamping section 222 is used to form a clamping gap 11 together with the fixed knife 10, wherein the extension direction of the second clamping section 222 is parallel to the extension direction of the fixed knife 10, which helps to ensure that the height of the clamping gap 11 remains unchanged along the extension direction of the fixed knife 10, and avoids the movable knife 30 from stopping swinging due to the reduction of the clamping gap 11 before it swings to the position where at least part of the first groove fits with the fixed knife 10.

[0039] In this embodiment, if Figure 6 As shown, the movable knife 30 includes a first end face 31 and a second end face 32 arranged opposite to each other. A first groove 33 is arranged on the first end face 31 so that after the movable knife 30 drives the line to pass through the clamping gap 11, the two sides of the line respectively abut against the second end face 32 and the second clamping section 222.

[0040] Specifically, the two sides of the cut bobbin thread respectively abut against the second end surface 32 and the second clamping section 222, so that the bobbin thread is firmly clamped between the movable knife 30 and the clamping member 20, thereby preventing the bobbin thread from falling down due to lack of support.

[0041] In this embodiment, if Figure 6 As shown, along the extension direction of the first groove 33, the first groove 33 has a closed end 331 and a free end 332 that are relatively arranged, so that the movable knife 30 is swung to a position where the closed end 331 is in contact with the fixed knife 10 to complete the thread cutting; wherein, along the direction from the free end 332 to the closed end 331, the distance between two adjacent groove walls of the first groove 33 gradually decreases.

[0042] Specifically, the blade 17 of the fixed knife 10 fits with the closed end 331 so that the blade 17 of the fixed knife 10 cuts the wire at the closed end 331, thereby ensuring that the wire cutting action is completed smoothly.

[0043] During specific implementation, when the movable knife 30 enters the clamping gap 11, the bottom line and the surface line are blocked by the fixed knife, and the bottom line and the surface line are gradually pressed from the free end 332 to the closed end 331 by the fixed knife 10. The movable knife 30 swings to a position where the closed end 331 fits with the fixed knife 10, and the blade of the fixed knife 10 fits with the closed end 331, and the blade of the fixed knife 10 cuts off the line at the closed end 331.

[0044] In this embodiment, if Figure 7 As shown, the thread trimming device further includes a transmission component, the drive motor 50 is drivingly connected to the transmission component, and the transmission component is drivingly connected to the movable knife 30, so that the drive motor 50 drives the movable knife 30 to swing through the transmission component.

[0045] Specifically, the driving motor 50 is used to drive the movable knife 30 to swing, and the transmission component is used to transmit and connect the driving motor 50 and the movable knife 30 to ensure that the movable knife 30 swings smoothly, thereby ensuring that the thread cutting action is completed smoothly.

[0046] Specifically, the driving motor 50 is a stepping motor, and the driving motor 50 is communicatively connected to the controller, and the user can control the rotation direction and rotation speed of the driving motor 50 through the controller.

[0047] In this embodiment, if Figure 7 As shown, the transmission component includes a first transmission crank 61 and a transmission rod 62. The first transmission crank 61 is connected to the output shaft of the driving motor 50. The first transmission crank 61 is hinged to one end of the transmission rod 62, and the other end of the transmission rod 62 is connected to the movable knife 30. The driving motor 50 drives the first transmission crank 61 to rotate and drives the transmission rod 62 to reciprocate in a preset direction, so that the transmission rod 62 drives the movable knife 30 to swing.

[0048] Specifically, the first transmission crank 61 and the transmission rod 62 jointly ensure the transmission reliability of the transmission component, thereby ensuring that the thread trimming action is completed smoothly.

[0049] In this embodiment, if Figure 7 As shown, the transmission component also includes a second transmission crank 63 and a third transmission crank 64. The two ends of the second transmission crank 63 are respectively connected to one end of the third transmission crank 64 and the transmission rod 62, and the other end of the third transmission crank 64 is connected to the movable knife 30, so that the transmission rod 62 drives the second transmission crank 63 to rotate, and the second transmission crank 63 drives the third transmission crank 64 and the movable knife 30 to swing.

[0050] Specifically, the second transmission crank 63 drives the third transmission crank 64 to transmit and connect the transmission rod 62 and the movable knife 30, thereby jointly ensuring the smooth swing of the movable knife 30, and further ensuring the smooth completion of the thread cutting action.

[0051] In this embodiment, if Figure 1As shown, the wire trimming device also includes a base 70 and a connecting plate 71, the connecting plate 71 is connected to the base 70, the connecting plate 71 is covered above the driving motor 50 and is connected to the driving motor 50, a through hole is opened on the connecting plate 71, and the output shaft of the driving motor 50 is passed through the through hole to be connected to the first transmission crank 61.

[0052] Specifically, the connecting plate 71 is used to connect the base 70 and the driving motor 50 to ensure stable operation of the driving motor 50 .

[0053] Specifically, the thread plate 80 is also disposed on the base 70 .

[0054] The utility model also provides a sewing machine, comprising the above-mentioned thread trimming device. The thread trimming device comprises a fixed knife 10, a clamping member 20, a driving motor 50 and a moving knife 30, wherein the clamping member 20 and the fixed knife 10 form a clamping gap 11, and the moving knife 30 has a first groove 33 for clamping the line to be cut, and the driving motor 50 drives the moving knife 30 to swing to a position where at least part of the first groove 33 fits with the fixed knife 10 to complete the thread trimming. During the swinging process of the moving knife 30, the moving knife 30 drives the line to pass through the clamping gap 11, so that the part of the line after cutting is clamped between the clamping member 20 and the moving knife 30, so that the part of the line cut no longer shakes, and is smoothly combined with the surface line, thereby ensuring the smooth progress of the sewing, thereby solving the problem of reduced sewing efficiency of the sewing machine in the prior art.

[0055] From the above description, it can be seen that the above embodiments of the utility model achieve the following technical effects:

[0056] The thread trimming device of the utility model comprises a fixed knife 10, a clamping member 20, a driving motor 50 and a movable knife 30. The clamping member 20 and the fixed knife 10 form a clamping gap 11. The movable knife 30 has a first groove 33 for clamping the line to be cut. The driving motor 50 drives the movable knife 30 to swing to a position where at least a portion of the first groove 33 fits with the fixed knife 10 to complete the thread trimming. During the swinging process of the movable knife 30, the movable knife 30 drives the line to pass through the clamping gap 11, so that the part of the line after cutting is clamped between the clamping member 20 and the movable knife 30, so that the part of the line cut no longer shakes, and is smoothly combined with the surface thread, thereby ensuring the smooth progress of the sewing, thereby solving the problem of reduced sewing efficiency of the sewing machine in the prior art.

[0057] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0058] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0059] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, 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 thread trimming device, characterized in that: include: Fixed knife (10); A clamping member (20) is arranged below the fixed knife (10) and forms a clamping gap (11) with the fixed knife (10); A movable knife (30) and a driving motor (50), wherein the movable knife (30) has a first groove (33) for clamping a line to be cut, and the driving motor (50) is connected to the movable knife (30) to drive the movable knife (30) to swing, so as to complete the line cutting by swinging the movable knife (30) to a position where at least a portion of the first groove (33) is in contact with the fixed knife (10); wherein, during the swinging of the movable knife (30), the movable knife (30) drives the line to pass through the clamping gap (11), so that the part of the line after cutting is clamped between the clamping member (20) and the movable knife (30).

2. The thread trimming device according to claim 1, characterized in that: The clamping member (20) comprises a connecting portion (21), the connecting portion (21) being in contact with the fixed knife (10), the connecting portion (21) being provided with a first connecting hole (6), the fixed knife (10) being provided with a second connecting hole, and fasteners being inserted into the first connecting hole (6) and the second connecting hole so as to fasten the connecting portion (21) to the fixed knife (10).

3. The thread trimming device according to claim 2, characterized in that: The clamping member (20) further comprises a clamping portion (22), wherein the clamping portion (22) comprises a first clamping section (221) and a second clamping section (222), wherein two ends of the first clamping section (221) are respectively connected to the second clamping section (222) and the connecting portion (21), wherein an extension direction of the second clamping section (222) is parallel to an extension direction of the fixed knife (10), and an extension direction of the first clamping section (221) is perpendicular to an extension direction of the second clamping section (222), and the clamping gap (11) is formed between the second clamping section (222) and the fixed knife (10) along the extension direction of the first clamping section (221).

4. The thread trimming device according to claim 3, characterized in that: The movable knife (30) comprises a first end face (31) and a second end face (32) which are arranged opposite to each other. The first end face (31) is provided with the first groove (33) so that after the movable knife (30) drives the line to pass through the clamping gap (11), two sides of the line respectively abut against the second end face (32) and the second clamping section (222).

5. The thread trimming device according to claim 1, characterized in that: Along the extension direction of the first groove (33), the first groove (33) has a closed end (331) and a free end (332) arranged opposite to each other, so that the movable knife (30) is swung to a position where the closed end (331) is in contact with the fixed knife (10) to complete the thread cutting; wherein, along the direction from the free end (332) to the closed end (331), the distance between two adjacent groove walls of the first groove (33) gradually decreases.

6. The thread trimming device according to claim 1, characterized in that: The thread trimming device further comprises a transmission component, the drive motor (50) is drivingly connected to the transmission component, and the transmission component is drivingly connected to the movable knife (30), so that the drive motor (50) drives the movable knife (30) to swing through the transmission component.

7. The thread trimming device according to claim 6, characterized in that: The transmission component comprises a first transmission crank (61) and a transmission rod (62); the first transmission crank (61) is connected to the output shaft of the driving motor (50); the first transmission crank (61) is hinged to one end of the transmission rod (62); the other end of the transmission rod (62) is transmission-connected to the movable knife (30), so that the driving motor (50) drives the first transmission crank (61) to rotate and drives the transmission rod (62) to reciprocate in a preset direction, so that the transmission rod (62) drives the movable knife (30) to swing.

8. The thread trimming device according to claim 7, characterized in that: The transmission component also includes a second transmission crank (63) and a third transmission crank (64), the two ends of the second transmission crank (63) are respectively connected to one end of the third transmission crank (64) and a transmission rod (62), and the other end of the third transmission crank (64) is connected to the movable knife (30), so that the transmission rod (62) drives the second transmission crank (63) to rotate, and the second transmission crank (63) drives the third transmission crank (64) and the movable knife (30) to swing.

9. The thread trimming device according to claim 7, characterized in that: The thread trimming device further comprises a base (70) and a connecting plate (71), wherein the connecting plate (71) is connected to the base (70), the connecting plate (71) is arranged above the driving motor (50) and is connected to the driving motor (50), and a through hole is provided on the connecting plate (71), and an output shaft of the driving motor (50) is passed through the through hole to be connected to the first transmission crank (61).

10. A sewing machine, characterized in that: The invention comprises the thread cutting device according to any one of claims 1 to 9.

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