Thread trimming and presser foot lifting driving device and sewing machine

Abstract

The present invention provides a thread trimming and presser foot lifting driving device and a sewing machine. The sewing machine comprises a machine body, a cutter assembly and a presser foot assembly. The thread trimming and presser foot lifting driving device comprises a motor, a driving crank, a presser foot lifting driving assembly, a pressure regulating assembly and a thread trimming driving assembly. The driving crank is connected to the rotating shaft of the motor. The driving crank has a first driving part and a second driving part. The first driving part is connected to the presser foot lifting driving assembly. The second driving part is detachably connected to the thread trimming driving assembly. The pressure regulating assembly follows the action of the presser foot lifting driving assembly and is used to adjust the force of the presser foot assembly. When the motor rotates forward, the first driving part drives the presser foot assembly to move through the presser foot lifting driving assembly. When the motor rotates reversely, the second driving part contacts the thread trimming driving assembly, and the second driving part drives the cutter assembly to move through the thread trimming driving assembly. The actions of thread trimming and presser foot lifting of the sewing machine can be realized by one motor. The structure is compact and the assembly and debugging requirements are low.

Description

Technical Field

[0001] The invention relates to the technical field of sewing, and in particular to a thread trimming and presser foot lifting driving device and a sewing machine. Background Art

[0002] Sewing machines can be divided into household sewing machines, industrial sewing machines and sewing machines for service industries according to their uses. Most of the industrial sewing machines are general-purpose sewing machines, including lockstitch machines, chainstitch machines, quilting machines, overlock machines and interlock machines. During the use of sewing machines, in order to increase the work efficiency of operators and reduce labor intensity, the use of automatic presser foot lifters has become more and more frequent.

[0003] The automatic thread trimmer and presser foot lifting device of the existing sewing machine are separate, and the automatic thread trimmer and presser foot lifting device are driven by electromagnets or cylinders to trim and reset the thread. The pneumatic presser foot lifting and thread trimmer take a long time to execute the entire action, react relatively slowly, and make a loud noise. The electromagnet presser foot lifting and thread trimmer take a short time to execute the entire action, react quickly, and make a small noise. However, when working for a long time, the electromagnet is easy to get hot, resulting in slow and weak presser foot lifting and thread trimmer reaction.

[0004] The Chinese invention patent with the authorization announcement number CN 207452400 U discloses a thread trimming, thread loosening and presser foot lifting action driving device for a flat sewing machine and a flat sewing machine, comprising a motor, a thread trimming driving member and a presser foot driving member; the thread trimming driving member comprises a thread trimming cam and a thread trimming driving rod; the thread trimming cam is connected to the motor shaft of the motor; the thread trimming driving rod is in contact with the circumferential surface of the thread trimming cam, and the thread trimming driving rod can move under the drive of the thread trimming cam to drive the thread loosening device and the thread trimming device to move; the presser foot driving member comprises a presser foot lifting cam and a presser foot connecting rod; the presser foot lifting cam is connected to the motor shaft of the motor; the presser foot connecting rod is in contact with the circumferential surface of the presser foot lifting cam, and the presser foot connecting rod can move under the drive of the presser foot lifting cam to drive the presser foot device to move; the position of the protruding portion of the presser foot lifting cam in the circumferential direction of the motor shaft has a specified angle difference relative to the position of the protruding portion of the thread trimming cam in the circumferential direction of the motor shaft, so that the action of the thread trimming device precedes the action of the presser foot device.

[0005] Although the above structure solves the defects of electromagnet-driven presser foot lifting and thread trimming, and realizes one motor to drive thread trimming and presser foot lifting, the actions are driven by the thread trimming cam and the presser foot lifting cam respectively, which has the defects of complex structure and high assembly difficulty. Summary of the invention

[0006] The purpose of the present invention is to provide a thread trimming and presser foot lifting drive device and a sewing machine, which realize the thread trimming and presser foot lifting actions of the sewing machine through a motor, have a compact structure, and have low assembly and debugging requirements, and can effectively improve the production efficiency of the whole machine and reduce production costs.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a thread trimming and presser foot lifting driving device, which is arranged on a sewing machine, the sewing machine comprising a machine body, a cutter assembly and a presser foot assembly, the thread trimming and presser foot lifting driving device comprising a motor, a driving crank, a presser foot lifting driving assembly, a pressure regulating assembly and a thread trimming driving assembly, the driving crank is connected to the rotating shaft of the motor and moves synchronously with the rotating shaft of the motor, the driving crank has a first driving part and a second driving part, the first driving part is connected to the presser foot lifting driving assembly, and the presser foot lifting driving assembly is connected to the presser foot assembly, and the second driving part can be detachably connected to the thread trimming driving assembly The first driving part is connected with the thread cutting driving assembly, and the thread cutting driving assembly is connected with the cutter assembly, the pressure regulating assembly is located at the connection between the presser foot lifting driving assembly and the presser foot assembly, the pressure regulating assembly follows the action of the presser foot lifting driving assembly and is used to adjust the force of the presser foot assembly; when the motor rotates forward, the first driving part drives the presser foot assembly to move through the presser foot lifting driving assembly, and the second driving part is in a separated state from the thread cutting driving assembly; when the motor rotates reversely, the second driving part contacts with the thread cutting driving assembly, and the second driving part drives the cutter assembly to move through the thread cutting driving assembly.

[0008] Optionally, the presser foot lifting drive assembly includes a first connecting rod mechanism, a first connecting crank, a first transmission shaft and a presser foot lifting arm, one end of the first connecting rod mechanism is fixedly connected to the first driving part, and the other end is fixedly connected to one end of the transmission crank, the other end of the first connecting crank is fixedly connected to one end of the first transmission shaft, the other end of the first transmission shaft is fixedly connected to one end of the presser foot lifting arm, and the other end of the presser foot lifting arm is fixedly connected to the presser foot assembly and the pressure regulating assembly. When the motor rotates forward, the first driving part drives the first connecting crank to rotate via the first connecting rod mechanism, the first transmission shaft rotates to follow the first connecting crank and drives the presser foot lifting arm to rotate, thereby driving the presser foot assembly and the pressure regulating assembly to move.

[0009] Optionally, the first connecting rod mechanism includes a first connecting member, a second connecting member and a pressure block, the first connecting member is vertically arranged, the second connecting member is horizontally arranged, one end of the first connecting member is fixedly connected to the first driving part, and the other end is fixedly connected to one end of the second connecting member, the other end of the second connecting member is rotatably connected to the casing of the sewing machine, the pressure block is fixed on the second connecting member, and the bottom end of the pressure block is detachably connected to the first connecting crank. When the motor rotates forward, the first connecting member moves downward, the second connecting member swings downward, the pressure block moves downward and presses the first connecting crank, and when the motor rotates reversely, the first connecting member moves upward, the second connecting member swings upward, and the pressure block moves upward and away from the first connecting crank.

[0010] Optionally, the first connecting member, the second connecting member and the first driving part are all fixedly connected by a fastener, and the fastener fixes the first connecting member, the second connecting member and the first driving part by a conical spring.

[0011] Optionally, the presser foot lifting drive assembly further includes a shock-absorbing spring sleeved on the first transmission shaft, the shock-absorbing spring is located at the connection between the first connecting crank and the first transmission shaft, and one end of the shock-absorbing spring is fixedly connected to the first connecting crank.

[0012] Optionally, the pressure regulating assembly includes a pressure regulating foot screw, a pressure regulating spring and a pressure rod head, one end of the pressure regulating foot screw is fixed to the casing of the sewing machine, and the other end is connected to one end of the pressure regulating spring, the other end of the pressure regulating spring is connected to one end of the pressure rod head, and the other end of the pressure rod head is connected to one end of the presser foot lifting arm and the presser foot assembly. In an initial state, the pressure regulating spring is in a compressed state, and when the motor rotates forward, the pressure regulating spring is further compressed.

[0013] Optionally, the thread cutting drive assembly includes a pressure rod, a second connecting rod mechanism and a second transmission shaft. The top end of the pressure rod is detachably connected to the second driving part, the bottom end of the pressure rod is fixedly connected to one end of the second connecting rod mechanism, the other end of the second connecting rod mechanism is fixedly connected to one end of the second transmission shaft, and the other end of the second transmission shaft is fixedly connected to the cutter assembly. When the motor rotates forward, the second driving part moves in a direction away from the pressure rod. When the motor rotates reversely, the second driving part contacts the pressure rod and drives the pressure rod to move downward. The pressure rod drives the second transmission shaft to rotate through the second connecting rod mechanism, thereby driving the cutter assembly to move.

[0014] Optionally, the second connecting rod mechanism includes a transmission lever, a transmission plate and a second connecting crank, the transmission lever is horizontally arranged, and the transmission plate is vertically arranged, one end of the transmission lever is fixedly connected to the bottom end of the pressure rod, the other end of the transmission lever is fixedly connected to a section of the transmission plate, the fulcrum of the transmission lever is fixed to the casing of the sewing machine, the other end of the transmission plate is rotatably connected to one end of the second connecting crank, the other end of the second connecting crank is fixedly connected to one end of the second transmission shaft, and the other end of the second transmission shaft is fixedly connected to the cutter assembly. When the motor rotates forward, the pressure rod moves downward and moves the transmission plate up through the transmission lever, and the second transmission shaft rotates and drives the cutter assembly to move.

[0015] Optionally, the thread trimmer drive assembly further comprises a return spring, one end of which is fixedly connected to the housing of the sewing machine, and the other end of which is connected to one end of the second connecting rod mechanism and the pressure rod.

[0016] Optionally, the pressure rod includes connecting heads at both ends and a center rod connecting the two connecting heads, the diameter of the connecting head is larger than the diameter of the center rod, a sleeve is sleeved on the center rod, the center rod can move axially relative to the sleeve, and shock-absorbing pads are respectively provided at both ends of the sleeve.

[0017] Based on this, the present invention also provides a sewing machine, including the thread trimming and presser foot lifting driving device.

[0018] In a thread trimming and presser foot lifting driving device and a sewing machine provided by the present invention, at least one of the following beneficial effects is achieved:

[0019] 1) By designing a driving crank with two driving parts, the forward and reverse rotation of the driving motor realizes the thread trimming and presser foot lifting actions of the sewing machine respectively. The structure is compact and the assembly and debugging requirements are low, which can effectively improve the production efficiency of the whole machine and reduce the production cost;

[0020] 2) When the motor rotates forward, the first driving unit drives the presser foot assembly to move through the presser foot lifting driving unit, and the second driving unit is in a separated state from the thread trimming driving unit. When the motor rotates reversely, the second driving unit contacts the thread trimming driving unit, and the second driving unit drives the cutter assembly to move through the thread trimming driving unit. The two actions of thread trimming and presser foot lifting are realized through the forward and reverse rotation of one motor. The structural design is ingenious and the operation is convenient.

[0021] 3) The height of the presser foot can be adjusted by controlling the speed of the motor, and debugging is simple and convenient;

[0022] 4) Pre-pressing the presser foot assembly with pressure through the pressure regulating assembly to facilitate pressing the fabric, and after the presser foot assembly completes the presser foot lifting action, the presser foot assembly is quickly reset to improve work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1-Figure 2 A schematic structural diagram of a thread trimming and presser foot lifting driving device provided in an embodiment of the present invention;

[0024] Figure 3 A three-dimensional diagram of a driving crank provided by an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of the structure of a conical spring provided in an embodiment of the present invention;

[0026] Figure 5 A schematic diagram of the structure of a shock absorbing spring provided in an embodiment of the present invention;

[0027] Figure 6 A schematic diagram of the structure of a shock-absorbing pad provided in an embodiment of the present invention;

[0028] Figure 7 A schematic structural diagram of a sewing machine provided by an embodiment of the present invention;

[0029] Wherein, the accompanying drawings are marked as follows:

[0030] 10-motor; 20-driving crank; 21-first driving part; 22-second driving part; 30-first connecting rod mechanism; 31-first connecting crank; 32-first transmission shaft; 33-presser foot lifting arm; 40-pressure regulating assembly; 50-conical spring; 51-shock absorbing spring; 60-pressing rod; 61-second connecting rod mechanism; 62-second transmission shaft; 63-reset spring; 70-sleeve; 71-shock absorbing pad; 80-machine body;

[0031] 301-first connecting member; 302-second connecting member; 303-pressing block; 401-pressure-adjusting foot screw; 402-pressure-adjusting spring; 403-pressure rod head; 611-transmission lever; 612-transmission plate; 613-second connecting crank. DETAILED DESCRIPTION

[0032] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0033] As used in the present invention, the singular forms "one", "an", and "the" include plural objects, unless the content clearly indicates otherwise. As used in the present invention, the term "or" is generally used in a sense that includes "and / or", unless the content clearly indicates otherwise. As used in the present invention, the term "several" is generally used in a sense that includes "at least one", unless the content clearly indicates otherwise. As used in the present invention, the term "at least two" is generally used in a sense that includes "two or more", unless the content clearly indicates otherwise. In addition, the terms "first", "second", and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features.

[0034] Please refer to Figure 1-Figure 2 , Figure 1-Figure 2The present invention is a structural schematic diagram of a thread trimming and presser foot lifting driving device provided in an embodiment of the present invention. The present embodiment provides a thread trimming and presser foot lifting driving device, which is arranged on a sewing machine. The sewing machine includes a machine body, a cutter assembly and a presser foot assembly. The thread trimming and presser foot lifting driving device includes a motor 10, a driving crank 20, a presser foot lifting driving assembly, a pressure regulating assembly 40 and a thread trimming driving assembly. The driving crank 20 is connected to the rotating shaft of the motor 10 and moves synchronously with the rotating shaft of the motor 10. The driving crank 20 has a first driving part 21 and a second driving part 22. The first driving part 21 is connected to the presser foot lifting driving assembly, and the presser foot lifting driving assembly is connected to the presser foot assembly. The second driving part 2 2 is detachably connected to the thread trimming drive assembly, and the thread trimming drive assembly is connected to the cutter assembly, the pressure regulating assembly 40 is located at the connection between the presser foot lifting drive assembly and the presser foot assembly, the pressure regulating assembly 40 follows the action of the presser foot lifting drive assembly and is used to adjust the force of the presser foot assembly, when the motor 10 rotates forward, the first driving part 21 drives the presser foot assembly to move through the presser foot lifting drive assembly, and the second driving part 22 is in a separated state from the thread trimming drive assembly, when the motor 10 rotates reversely, the second driving part 22 contacts the thread trimming drive assembly, and the second driving part 22 drives the cutter assembly to move through the thread trimming drive assembly.

[0035] In this embodiment, the thread trimming and presser foot lifting driving device is applied to an overlock sewing machine, and can also be applied to other types of sewing machines such as a stretch sewing machine and a lockstitch sewing machine. In addition, the thread trimming and presser foot lifting driving device can be applied to an integrated sewing machine or a non-integrated sewing machine, and this application does not impose any limitation on this.

[0036] Please refer to Figure 3 , Figure 3 A three-dimensional diagram of a driving crank provided in an embodiment of the present invention. The driving crank 20 has a first driving portion 21 and a second driving portion 22, and the first driving portion 21 and the second driving portion 22 are respectively used to drive the presser foot lifting driving component and the thread trimming driving component, that is, in this embodiment, by designing a driving crank 20 with two driving parts, the actions of thread trimming and presser foot lifting of the sewing machine are realized, the structure is simple, and it is easy to assemble, which can effectively improve the production efficiency of the whole machine and reduce the production cost.

[0037] In this embodiment, the first driving part 21 can be fixedly connected to the presser foot lifting driving assembly by means of thread connection, pin connection, etc. When the rotating shaft of the motor 10 rotates, the driving crank 20 is driven to rotate, thereby driving the presser foot lifting driving assembly to move. The second driving part 22 is detachably connected to the thread trimming driving assembly. The detachable type can be understood as that the second driving part 22 is not fixedly connected to the thread trimming driving assembly. When the motor 10 rotates forward, the second driving part 22 will move in a direction away from the thread trimming driving assembly. At this time, the presser foot lifting driving assembly drives the presser foot assembly to move and complete the presser foot lifting action. The thread trimming driving assembly and the cutter assembly do not move. Only when the motor 10 reverses, the second driving part 22 will contact the thread trimming driving assembly and drive the cutter assembly to complete the thread trimming action. At this time, the presser foot lifting driving assembly moves, but the presser foot assembly does not move.

[0038] Please continue to refer to Figure 1-Figure 2 The presser foot lifting driving assembly includes a first connecting rod mechanism 30, a first connecting crank 31, a first transmission shaft 32 and a presser foot lifting arm 33, one end of the first connecting rod mechanism 30 is fixedly connected to the first driving part 21, and the other end is fixedly connected to one end of the first connecting crank 31, the other end of the first connecting crank 31 is fixedly connected to one end of the first transmission shaft 32, the other end of the first transmission shaft 32 is fixedly connected to one end of the presser foot lifting arm 33, the other end of the presser foot lifting arm 33 is fixedly connected to the presser foot assembly and the pressure regulating assembly 40, and the first transmission shaft 32 is connected to the casing of the sewing machine and can rotate relative to the casing. When the motor 10 rotates forward, the first driving part 21 drives the first connecting crank 31 to rotate through the first connecting rod mechanism 30, the first transmission shaft 32 rotates to follow the first connecting crank 31 and drives the presser foot lifting arm 33 to rotate, thereby driving the presser foot assembly and the pressure regulating assembly 40 to act.

[0039] Furthermore, the first connecting rod mechanism 30 includes a first connecting member 301, a second connecting member 302 and a pressure block 303, the first connecting member 301 is vertically arranged, the second connecting member 302 is horizontally arranged, one end of the first connecting member 301 is fixedly connected to the first driving part 21, and the other end is fixedly connected to one end of the second connecting member 302, the other end of the second connecting member 302 is rotatably connected to the casing of the sewing machine, the pressure block 303 is fixed on the second connecting member 302, and the bottom end of the pressure block 303 is detachably connected to the first connecting crank 31.

[0040] When the motor 10 rotates forward, the driving crank 20 rotates counterclockwise (from Figure 1(see Figure 3) , the first connecting member 301 moves downward, and since one end of the second connecting member 302 is rotatably connected to the casing, when the first connecting member 301 moves downward, the end of the second connecting member 302 fixed to the first connecting member 301 swings downward, and the pressing block 303 on the second connecting member 302 moves downward and presses the first connecting crank 31 to drive, so that the first connecting crank 31 drives the first transmission shaft 32 to rotate clockwise, and then drives the presser foot lifting arm 33 to swing upward, thereby completing the presser foot lifting action.

[0041] In this embodiment, the fixing method includes but is not limited to threaded connection and pin connection. In this embodiment, the presser foot assembly is a sewing machine component well known to those skilled in the art.

[0042] It should be understood that when the motor 10 is reversed, the driving crank 20 rotates clockwise, the first connecting member 301 moves upward, and the second connecting member 302 swings upward. At this time, the pressing block 303 moves upward and away from the first connecting crank 31, so that the transmission is interrupted, and the subsequent presser foot lifting arm 33 and presser foot assembly do not operate. In other words, when the motor 10 rotates forward, the presser foot lifting driving assembly operates, the presser foot assembly operates, and the thread trimming driving assembly does not operate; when the motor 10 is reversed, the presser foot lifting driving assembly is disconnected from the pressing block 303 and the first connecting crank 31, the presser foot assembly does not operate, the thread trimming driving assembly operates, and the cutter assembly operates.

[0043] Please refer to Figure 4 , Figure 4 Schematic diagram of a conical spring provided in an embodiment of the present invention. The first connecting member 301 is fixedly connected to the second connecting member 302 and the first driving part 21 by a fastener, and the fastener fixes the first connecting member 301, the second connecting member 302 and the first driving part 21 by a conical spring 50. It can be understood that when the driving crank 20 rotates counterclockwise, the first connecting member 301 is driven to move downward, and the second connecting member 302 is swung downward, so that the first connecting member 301 is subjected to vertical and horizontal forces, which is easy to generate noise and wear the first connecting member 301. By setting the conical spring 50 for connection, the rigid transmission of force can be effectively reduced, replacing the universal joint, and reducing the noise when the sewing machine is working. In this embodiment, the end of the second connecting member 302 is bent 90° to form a connecting portion, and threaded holes are correspondingly provided on the end of the first connecting member 301 and the connecting portion. The fastener includes but is not limited to a bolt, and the bolt passes through the threaded hole and is locked by a nut. The conical spring 50 is located between the first connecting member 301 and the head of the bolt and is in a compressed state.

[0044] For further information, please refer to Figure 5 , Figure 5 Schematic diagram of a shock-absorbing spring provided in an embodiment of the present invention. The presser foot lifting drive assembly further includes a shock-absorbing spring 51 sleeved on the first transmission shaft 32, the shock-absorbing spring 51 is located at the connection between the first connecting crank 31 and the first transmission shaft 32, and one end of the shock-absorbing spring 51 is fixedly connected to the first connecting crank 31. In this embodiment, during the process of the presser foot assembly being frequently lifted and pressed down, the first transmission shaft 32 shakes during the force transmission process, generating noise, and the shock-absorbing spring 51 can be provided to prevent shaking and prevent the generation of noise.

[0045] Please continue to refer to Figure 1-Figure 2 , the pressure regulating assembly 40 comprises a pressure regulating foot screw 401, a pressure regulating spring 402 and a pressure rod head 403, one end of the pressure regulating foot screw 401 is fixed on the housing of the sewing machine, and the other end is connected to one end of the pressure regulating spring 402, the other end of the pressure regulating spring 402 is connected to one end of the pressure rod head 403, and the other end of the pressure rod head 403 is connected to one end of the presser foot lifting arm 33 and the presser foot assembly. In the initial state, the pressure regulating spring 402 is in a compressed state, and when the motor 10 rotates forward, the pressure regulating spring 402 is further compressed. When the presser foot assembly is pressed on the cloth, a certain pressure can be applied by the pressure regulating spring 402 to facilitate pressing the cloth. When the motor 10 rotates forward, the compression spring is released so that the presser foot assembly can be quickly reset to improve work efficiency. In this embodiment, the pressure applied to the presser foot assembly can be changed by adjusting the initial compression amount of the pressure regulating spring 402.

[0046] Please continue to refer to Figure 1-Figure 2 The cutter assembly is a sewing machine component well known to those skilled in the art. The thread trimmer drive assembly includes a pressure rod 60, a second connecting rod mechanism 61 and a second transmission shaft 62. The top end of the pressure rod 60 is detachably connected to the second drive unit 22, the bottom end of the pressure rod 60 is fixedly connected to one end of the second connecting rod mechanism 61, the other end of the second connecting rod mechanism 61 is fixedly connected to one end of the second transmission shaft 62, and the other end of the second transmission shaft 62 is fixedly connected to the cutter assembly. When the motor 10 rotates forward, the second driving unit 22 moves in a direction away from the pressure rod 60. When the motor 10 rotates reversely, the second driving unit 22 contacts the pressure rod 60 and drives the pressure rod 60 to move downward. The pressure rod 60 drives the second transmission shaft 62 to rotate through the second connecting rod mechanism 61, thereby driving the cutter assembly to move.

[0047] Furthermore, the second connecting rod mechanism includes a transmission lever 611, a transmission plate 612 and a second connecting crank 613, the transmission lever 611 is horizontally arranged, the transmission plate 612 is vertically arranged, one end of the transmission lever 611 is fixedly connected to the bottom end of the pressure rod 60, the other end of the transmission lever is fixedly connected to a section of the transmission plate 612, the fulcrum of the transmission lever is fixed to the casing of the sewing machine, the other end of the transmission plate 612 is rotatably connected to one end of the second connecting crank 613, the other end of the second connecting crank 613 is fixedly connected to one end of the second transmission shaft 62, the other end of the second transmission shaft 62 is fixedly connected to the cutter assembly, when the motor 10 rotates forward, the pressure rod 60 moves downward and the transmission plate 612 moves upward through the transmission lever, the second transmission shaft 62 rotates and drives the cutter assembly to move, thereby completing the thread cutting action.

[0048] Furthermore, the thread trimming drive assembly further includes a reset spring 63, one end of which is fixedly connected to the housing of the sewing machine, and the other end is connected to one end of the second connecting rod mechanism and the pressure rod 60. When the motor 10 rotates in reverse, the pressure rod 60 moves downward, and the reset spring 63 is stretched. After the thread trimming action is completed, the motor 10 rotates forward, and the pressure rod 60 moves upward under the elastic force of the reset spring 63, driving the transmission lever and subsequent parts to reset.

[0049] For further information, please refer to Figure 6 , Figure 6 Schematic diagram of a shock-absorbing pad provided in an embodiment of the present invention. The pressure rod 60 includes connectors at both ends and a center rod connecting the two connectors. The diameter of the connector is larger than the diameter of the center rod. A sleeve 70 is sleeved on the center rod. The center rod can move axially relative to the sleeve 70, and shock-absorbing pads 71 ​​are respectively provided at both ends of the sleeve 70. The sleeve 70 is used to limit the up and down movement of the pressure rod 60 to ensure the accuracy of the thread cutting action. The shock-absorbing pad 71 is used to prevent the connector from directly contacting the sleeve 70 and play a buffering role.

[0050] In this embodiment, the motor 10 is a stepper motor or a grating motor, which has high positioning accuracy and fast response, and will not cause the presser foot to be lifted or the thread to be cut weakly, thereby effectively improving the production efficiency of the whole machine and reducing the production cost.

[0051] Based on this, please refer to Figure 7The present embodiment further provides a sewing machine, which comprises a machine body 80, a cutter assembly and a presser foot assembly, and the above-mentioned thread trimming and presser foot lifting driving device. In the present embodiment, the thread trimming and presser foot lifting driving device is integrally installed in the machine body 80, has a compact structure, occupies a small space, and is conducive to the miniaturization of the sewing machine. The motor 10 of the thread trimming and presser foot lifting driving device is installed at the bottom of the machine body 80, which can increase the stability of the machine body 80, reduce the vibration caused by the motor 10 when working, and thus reduce noise.

[0052] In summary, the embodiments of the present invention provide a thread trimming and presser foot lifting drive device and a sewing machine. When the motor rotates forward, the first drive unit drives the presser foot assembly to move through the presser foot lifting drive assembly, and the second drive unit is in a separated state from the thread trimming drive assembly. When the motor rotates reversely, the second drive unit contacts the thread trimming drive assembly, and the second drive unit drives the cutter assembly to move through the thread trimming drive assembly. By designing a driving crank with two driving parts, the forward and reverse rotations of the driving motor respectively realize the thread trimming and presser foot lifting actions of the sewing machine. The structure is compact, and the assembly and debugging requirements are low. The production efficiency of the whole machine can be effectively improved and the production cost can be reduced.

[0053] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.

Claims

1. A thread trimming and presser foot lifting driving device, arranged on a sewing machine, the sewing machine comprising a machine body, a cutter assembly and a presser foot assembly, characterized in that: The thread trimming and presser foot lifting driving device comprises a motor, a driving crank, a presser foot lifting driving assembly, a pressure regulating assembly and a thread trimming driving assembly, wherein the driving crank is connected to the rotating shaft of the motor and moves synchronously with the rotating shaft of the motor, the driving crank has a first driving part and a second driving part, the first driving part is connected to the presser foot lifting driving assembly, and the presser foot lifting driving assembly is connected to the presser foot assembly, the second driving part is detachably connected to the thread trimming driving assembly, and the thread trimming driving assembly is connected to the cutter assembly, the pressure regulating assembly is located at the connection between the presser foot lifting driving assembly and the presser foot assembly, the pressure regulating assembly follows the action of the presser foot lifting driving assembly and is used to adjust the force of the presser foot assembly, when the motor rotates forward, the first driving part drives the presser foot assembly to move through the presser foot lifting driving assembly, the second driving part and the thread trimming driving assembly are in a separated state, when the motor rotates reversely, the second driving part contacts the thread trimming driving assembly, and the second driving part drives the cutter assembly to move through the thread trimming driving assembly; The presser foot lifting driving assembly includes a first connecting rod mechanism, a first connecting crank, a first transmission shaft and a presser foot lifting arm, one end of the first connecting rod mechanism is fixedly connected to the first driving part, and the other end is fixedly connected to one end of the first connecting crank, the other end of the first connecting crank is fixedly connected to one end of the first transmission shaft, the other end of the first transmission shaft is fixedly connected to one end of the presser foot lifting arm, and the other end of the presser foot lifting arm is fixedly connected to the presser foot assembly and the pressure regulating assembly. When the motor rotates forward, the first driving part drives the first connecting crank to rotate through the first connecting rod mechanism, the first transmission shaft rotates to follow the rotation of the first connecting crank and drives the presser foot lifting arm to rotate, thereby driving the presser foot assembly and the pressure regulating assembly to act; The first connecting rod mechanism comprises a first connecting member, a second connecting member and a pressing block, the first connecting member is arranged vertically, the second connecting member is arranged horizontally, one end of the first connecting member is fixedly connected to the first driving part, the other end of the first connecting member is fixedly connected to one end of the second connecting member, the other end of the second connecting member is rotatably connected to the casing of the sewing machine, the pressing block is fixedly arranged on the second connecting member, the bottom end of the pressing block is detachably connected to the first connecting crank, when the motor rotates forward, the first connecting member moves downward, the second connecting member swings downward, the pressing block moves downward and presses the first connecting crank, when the motor rotates reversely, the first connecting member moves upward, the second connecting member swings upward, the pressing block moves upward and away from the first connecting crank; The thread trimmer drive assembly includes a pressure rod, a second connecting rod mechanism and a second transmission shaft, the top end of the pressure rod is detachably connected to the second driving part, the bottom end of the pressure rod is fixedly connected to one end of the second connecting rod mechanism, the other end of the second connecting rod mechanism is fixedly connected to one end of the second transmission shaft, and the other end of the second transmission shaft is fixedly connected to the cutter assembly, when the motor rotates forward, the second driving part moves in a direction away from the pressure rod, when the motor rotates reversely, the second driving part contacts the pressure rod and drives the pressure rod to move downward, and the pressure rod drives the second transmission shaft to rotate through the second connecting rod mechanism, thereby driving the cutter assembly to move; The mechanism includes a transmission lever, a transmission plate and a second connecting crank. The transmission lever is horizontally arranged, and the transmission plate is vertically arranged. One end of the transmission lever is fixedly connected to the bottom end of the pressure rod, and the other end of the transmission lever is fixedly connected to a section of the transmission plate. The fulcrum of the transmission lever is fixed to the casing of the sewing machine. The other end of the transmission plate is rotatably connected to one end of the second connecting crank, and the other end of the second connecting crank is fixedly connected to one end of the second transmission shaft. The other end of the second transmission shaft is fixedly connected to the cutter assembly. When the motor rotates forward, the pressure rod moves downward and moves the transmission plate upward through the transmission lever, and the second transmission shaft rotates and drives the cutter assembly to move.

2. The thread trimming and presser foot lifting driving device according to claim 1, characterized in that: The first connecting member, the second connecting member and the first driving part are all fixedly connected by a fastener, and the fastener fixes the first connecting member, the second connecting member and the first driving part by a conical spring.

3. The thread trimming and presser foot lifting driving device according to claim 1, characterized in that: The presser foot lifting drive assembly also includes a shock-absorbing spring sleeved on the first transmission shaft. The shock-absorbing spring is located at the connection between the first connecting crank and the first transmission shaft, and one end of the shock-absorbing spring is fixedly connected to the first connecting crank.

4. The thread trimming and presser foot lifting driving device according to claim 1, characterized in that: The pressure regulating assembly includes a pressure regulating foot screw, a pressure regulating spring and a pressure rod head, one end of the pressure regulating foot screw is fixed to the casing of the sewing machine, and the other end is connected to one end of the pressure regulating spring, the other end of the pressure regulating spring is connected to one end of the pressure rod head, and the other end of the pressure rod head is connected to one end of the presser foot lifting arm and the presser foot assembly. In the initial state, the pressure regulating spring is in a compressed state, and when the motor rotates forward, the pressure regulating spring is further compressed.

5. The thread trimming and presser foot lifting driving device according to claim 1, characterized in that: The thread trimmer drive assembly also includes a return spring, one end of which is fixedly connected to the housing of the sewing machine, and the other end of which is connected to the second connecting rod mechanism and one end of the pressure rod.

6. The thread trimming and presser foot lifting driving device according to claim 1, characterized in that: The pressure rod includes connecting heads at both ends and a center rod connecting the two connecting heads. The diameter of the connecting head is larger than the diameter of the center rod. A sleeve is sleeved on the center rod. The center rod can move axially relative to the sleeve, and shock-absorbing pads are respectively provided at both ends of the sleeve.

7. A sewing machine, characterized in that: It comprises the thread trimming and presser foot lifting driving device as described in any one of claims 1-6.

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