Motor-driven thread trimming device of sewing machine

Abstract

The utility model provides a motor-driven thread trimming device of a sewing machine. The motor-driven thread trimming device of the sewing machine comprises a machine base, a motor driving device, a linkage device and a thread trimming execution device, according to the motor-driven thread trimming device of the sewing machine, the stepping motor is innovatively introduced to serve as a driving source, the stepping motor drives the eccentric wheel to further drive the linkage device, and therefore a movable cutter of the thread trimming execution device is driven to linearly move front and back to achieve thread trimming operation; the device has the advantage of modular design, and the design of a cam mechanism with high difficulty is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of industrial sewing machines, in particular to a motor-driven thread trimming device of a sewing machine. Background Art

[0002] At present, the common thread trimming mechanism of sewing machines is: the electromagnet sends a signal, and the cam mechanism drives the thread trimmer to cut the thread. The cam mechanism of this type is difficult to design and has a complex structure. Utility Model Content

[0003] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a motor-driven thread trimming device for a sewing machine, which avoids the difficult and complex cam mechanism design.

[0004] To achieve the above purpose, the solution adopted by the utility model is as follows:

[0005] The utility model provides a motor-driven thread trimming device for a sewing machine, comprising a machine base, a motor driving device fixed on the machine base, a linkage device and a thread trimming execution device; wherein:

[0006] The motor drive device comprises a stepper motor with a drive shaft;

[0007] The linkage device comprises:

[0008] An eccentric wheel, hinged to the driving shaft of the stepping motor;

[0009] A first swing rod assembly, comprising a first swing rod and a first roller capable of axial rotation;

[0010] A second swing rod assembly, comprising a second swing rod and a second roller capable of axial rotation;

[0011] A connecting rod connecting the first swing rod and the second swing rod;

[0012] The eccentric wheel can be in rolling contact with the cylindrical surface of the first roller and the cylindrical surface of the second roller;

[0013] The thread trimming execution device comprises a movable knife and a fixed knife;

[0014] The second swing arm assembly also includes a pushing portion for pushing the movable knife to perform linear forward and backward motion.

[0015] Preferably, the base includes a first platform and a second platform, the motor drive device and the linkage device are fixed on the first platform, the drive shaft of the stepper motor is vertically fixed on the first platform, and the thread trimming actuator is fixed on the second platform.

[0016] Preferably, the first rocker assembly further comprises a first axial screw for axially rotating and fixing the first rocker on the first platform, and the second rocker assembly further comprises a second axial screw for axially rotating and fixing the second rocker on the first platform.

[0017] Preferably, two ends of the connecting rod are connected to the first swing rod and the second swing rod respectively through a third axial screw and a fourth axial screw.

[0018] Preferably, the pushing portion of the second rocker assembly includes a fifth axial screw located at the end of the second rocker.

[0019] Preferably, a long groove extending along the linear forward and backward movement direction of the movable knife is provided on the second platform, and a sliding block is arranged in the long groove, and the sliding block can make linear forward and backward movement in the long groove; a sliding groove is provided on the sliding block, and the fifth axial screw can move in the sliding groove.

[0020] Preferably, one end of the movable knife of the thread trimming actuator is fixed on a movable knife fixing block, and the movable knife fixing block is placed on the sliding block and can contact the end of the second rocker arm.

[0021] Preferably, a sliding portion extending along the linear forward and backward movement direction of the moving knife is provided on the moving knife fixing block; a moving knife guide seat extending along the linear forward and backward movement direction of the moving knife is provided on the second platform, and when the moving knife of the thread cutting actuator moves linearly forward and backward, the sliding portion of the moving knife fixing block slides under the linear guidance of the moving knife guide seat.

[0022] Preferably, the movable knife guide seat is arranged on one side of the long groove on the second platform, and a pressure plate is provided on the other side of the long groove, which is used to press the sliding block into the long groove, and the fifth axial screw of the second rocker arm assembly can abut against the side of the pressure plate during the process of linear forward and backward movement in the long groove.

[0023] Preferably, one end of the fixed knife of the thread trimming actuator is fixed on a fixed knife fixing block, and the fixed knife fixing block is fixed on the second platform; the other end of the fixed knife is a fixed knife blade, and the other end of the movable knife is a movable knife blade, and a spring sheet is also provided below the movable knife blade for adjusting the distance between the movable knife blade and the fixed knife blade when the movable knife makes a linear motion to reach the fixed knife blade, and the spring sheet is fixed on a spring adjustment platform; preferably, the spring adjustment platform is fixed on the movable knife guide seat; preferably, a movable knife auxiliary support plate is also provided between the movable knife blade of the movable knife and the spring sheet, and more preferably, the movable knife auxiliary support plate is fixed on the movable knife guide seat.

[0024] Beneficial Effects

[0025] The utility model provides a motor-driven thread trimming device for a sewing machine, which innovatively introduces a stepping motor as a driving source, wherein the stepping motor drives an eccentric wheel and then drives a linkage device, thereby driving a movable knife of a thread trimming actuator to move back and forth in a straight line to realize a thread trimming operation; the device has the advantage of modular design and avoids the more difficult cam mechanism design. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The utility model is a three-dimensional structural schematic diagram of a motor-driven thread trimming device of a sewing machine.

[0027] Figure 2 The utility model is an exploded structural diagram of a motor-driven thread trimming device of a sewing machine.

[0028] Figure 3 The utility model relates to a relative position diagram of a movable knife and a fixed knife of a motor-driven thread trimming device of a sewing machine in a thread trimming movement direction.

[0029] Figure 4 The utility model relates to a relative position diagram of a power source of a motor-driven thread trimming device of a sewing machine and a fixed knife when thread trimming is completed. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0034] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0035] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] To this end, the following solutions are proposed:

[0037] See also Figure 1 , Figure 2 The utility model provides a motor-driven thread trimming device for a sewing machine, comprising a machine base 100 and a motor driving device 200, a linkage device 300 and a thread trimming actuator 400 fixed on the machine base 100.

[0038] Specifically, the motor drive device 200 includes a stepper motor 201 with a drive shaft 202. The base 100 includes a first platform 101 and a second platform 102. The motor drive device 200 and the linkage device 300 are fixed on the upper plane of the first platform 101. The drive shaft 202 of the stepper motor 201 is vertically fixed on the first platform 101. The stepper motor 201 is fixed on the lower plane of the first platform 101 by screws 501, 502, 503, and 504. The thread trimming actuator 400 is fixed on the upper plane of the second platform 102.

[0039] The linkage device 300 includes an eccentric wheel 301, a first pendulum component 302, and a second pendulum component 303. The eccentric wheel 301 is fixedly connected to the driving shaft 202 of the stepping motor 201 through screws 505 and 506, and the stepping motor 201 drives the rotation of the eccentric wheel 301. The first pendulum component 302 includes a first swing rod 304 and a first roller 305 that can rotate axially, and the second pendulum component 303 includes a second swing rod 306 and a second roller 307 that can rotate axially, wherein the eccentric wheel 301 can roll with the cylindrical surface of the first roller 305 and the cylindrical surface of the second roller 307, so that the eccentric wheel 301 rotates under the drive of the stepping motor 201, driving the first roller 305 or the second roller 307 to roll on the cylindrical surface of the eccentric wheel 301.

[0040] Furthermore, the first pendulum component 302 also includes a first axial screw 308 for axially rotating and fixing the first pendulum rod 304 on the first platform 101, and the second pendulum component 303 also includes a second axial screw 309 for axially rotating and fixing the second pendulum rod 306 on the second platform 102.

[0041] The linkage device 300 further includes a connecting rod 310 connecting the first swing rod 304 and the second swing rod 306 . In a preferred embodiment, both ends of the connecting rod 310 are connected to the first swing rod 304 and the second swing rod 306 respectively through a third axial screw 311 and a fourth axial screw 312 .

[0042] The thread trimming actuator 400 includes a movable knife 401 and a fixed knife 402. Figure 3 The present invention provides a relative position diagram of a movable knife 401 and a fixed knife 402 of a motor-driven thread trimming device of a sewing machine in the thread trimming direction. Figure 3 In the process, the movable knife 401 moves back and forth in a straight line in the thread cutting direction, and the fixed knife 402 remains stationary. Figure 4 When the thread is in the position shown, the thread trimming operation is completed.

[0043] In a motor-driven thread trimming device of a sewing machine of the utility model, the second swing arm assembly 303 further includes a pushing portion 313 for pushing the movable knife 401 to perform a linear forward and backward motion. The eccentric wheel 301 is driven by the stepping motor 201 to rotate axially, and the first swing arm 304, the second swing arm 306 and the connecting rod 310 are pushed to perform a linear forward and backward motion through rolling contact with the first roller 305 and the second roller 307, thereby driving the movable knife 401 of the thread trimming actuator 400 to perform a linear forward and backward motion to achieve thread trimming.

[0044] In some embodiments, the pusher 313 of the second swing rod assembly 303 includes a fifth axial screw 314 located at the end of the second swing rod 306. In addition, a long slot 403 extending along the linear forward and backward movement direction of the movable knife 401 is provided on the second platform 102, and a slider 404 is provided in the long slot 403. The slider 404 can move linearly forward and backward in the long slot 403, and a sliding slot 4041 is provided on the slider 404, and the fifth axial screw 314 can move in the sliding slot 4041. The eccentric wheel 301 rotates axially when driven by the stepper motor 201, and promotes the linkage between the first rocker arm 304, the second rocker arm 306 and the connecting rod 310 through rolling contact with the first roller 305 and the second roller 307. The fifth axial screw 314 at the end of the second rocker arm 306 swings back and forth around the first axial screw 308 of the second rocker assembly 303. The fifth axial screw 314 stuck in the sliding groove 4041 drives the slider 404 to slide back and forth in a straight line in the long groove 403 on the second platform 102.

[0045] Furthermore, one end of the moving knife 401 of the thread trimming actuator 400 is fixed to the moving knife fixing block 405 by screws 518 and 519. The moving knife fixing block 405 is placed on the slider 404, and the moving knife fixing block 405 can contact the end of the second swing rod 306. During the forward and backward swinging of the second swing rod 306, the fifth axial screw 314 drives the slider 404 to slide forward and backward in a straight line in the long groove 403 on the second platform 102, thereby driving the moving knife fixing block 405 on the slider 404 to move forward and backward, thereby realizing the moving knife 401 to do the following Figure 3 The straight line forward and backward motion shown in the figure realizes the thread trimming operation.

[0046] In a preferred embodiment, a sliding portion 4051 extending along the linear forward and backward movement direction of the movable knife 401 is provided on the movable knife fixing block 405. A movable knife guide seat 406 extending along the linear forward and backward movement direction of the movable knife 401 is provided on the second platform 102, and the movable knife guide seat 406 is fixed to the second platform 102 by screws 505 and 520. When the movable knife 401 of the thread trimming actuator 400 moves forward and backward in a linear manner, the sliding portion 4051 of the movable knife fixing block 405 slides under the linear guidance of the movable knife guide seat 406, which is more conducive to the movable knife 401 to make a smooth linear forward and backward movement.

[0047] In a further preferred embodiment, the movable knife guide seat 406 is arranged on one side of the long groove 403 on the second platform 102, and a pressure plate 407 is provided on the other side of the long groove 403 for pressing the slider 404 into the long groove 403. The pressure plate 407 is fixed to the second platform 102 and one side of the long groove 403 by screws 507 and 508, and the fifth axial screw 314 of the second rocker arm assembly 303 can abut against the side of the pressure plate 407 during the process of making a linear forward and backward movement in the long groove 403, which is more conducive to the fifth axial screw 314 of the second rocker arm assembly 303 to make a smooth linear forward and backward movement in the long groove 403.

[0048] In a motor-driven thread trimming device of a sewing machine of the utility model, one end of the fixed knife 402 of the thread trimming actuator 400 is fixed to the fixed knife fixing block 408 by screws 509 and 510, and the fixed knife fixing block 408 is fixed to the machine base 100 by screws 511, 512, and 513. The other end of the fixed knife 402 is a fixed knife blade 4021, and the other end of the movable knife 401 is a movable knife blade 4011 (such as Figure 3 , Figure 4 As shown), a portion for adjusting the movable knife 401 when the movable knife 401 makes a linear motion to reach the fixed knife blade 4021 (i.e. Figure 4 The spring sheet 409 is fixed to the spring adjustment platform 410 by screws 514, and the spring adjustment platform 410 is fixed to the moving knife guide seat 406 by screws 521. In some embodiments, a moving knife auxiliary support plate 411 is further provided between the moving knife blade 4011 of the moving knife 401 and the spring sheet 409, and the moving knife auxiliary support plate 411 is fixed to the moving knife guide seat 406 by screws 516 and 517. The rotary hook 412 is placed in the shaft hole of the machine base 100 to complete the thread cutting action.

[0049] See also Figure 1 , Figure 2The utility model provides a motor-driven thread trimming device for a sewing machine, and its implementation process is as follows: the eccentric wheel 301 is hinged with the driving shaft 202 of the stepping motor 201, and the stepping motor 201 drives the rotation of the eccentric wheel 301, and the eccentric wheel 301 rotates counterclockwise; when the eccentric wheel 301 touches the second roller 307, it will drive the second swing rod 306 to move through the connecting rod 310, and the pushing part 313 on the second swing rod 306 and its fifth axial screw 314 will move accordingly, and the fifth axial screw 314 is in the sliding groove 4041 of the slider 404 in the long groove 403 on the second platform 102, and the fifth axial screw 314 drives the slider 404 to move forward along the long groove 403 on the second platform 102, thereby driving the moving knife fixing block 405 on the slider 404 to move forward, and the moving knife 401 on the moving knife fixing block 405 also moves backward accordingly ( Figure 3 The A direction is backward and the B direction is forward) to the frontmost position (such as Figure 3 The movable blade 4011 of the movable knife 401 extends to the frontmost position ( Figure 3 The eccentric wheel 301 continues to move counterclockwise and separates from the second roller 307, touching the first roller 305 on the first swing rod 304, driving the connecting rod 310 to move, the connecting rod 310 drives the second swing rod 306 to move, the pushing portion 313 on the second swing rod 306 and the fifth axial screw 314 thereof will move accordingly, the fifth axial screw 314 drives the slider 404 to move backward along the long slot 403 on the second platform 102, thereby driving the moving knife fixing block 405 on the slider 404 to move backward, and the moving knife 401 on the moving knife fixing block 405 also moves backward accordingly to the position as shown in FIG. Figure 4 The position shown in the figure is interlaced with the fixed knife blade 4021 of the fixed knife 402 to complete the thread cutting action.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A motor-driven thread trimming device for a sewing machine, characterized in that: It includes a machine base and a motor drive device, a linkage device and a thread trimming actuator fixed on the machine base; wherein: The motor drive device comprises a stepper motor with a drive shaft; The linkage device comprises: An eccentric wheel, hinged to the driving shaft of the stepping motor; A first swing rod assembly, comprising a first swing rod and an axially rotatable first roller; A second swing rod assembly, comprising a second swing rod and a second roller capable of axial rotation; A connecting rod connecting the first swing rod and the second swing rod; The eccentric wheel can be in rolling contact with the cylindrical surface of the first roller and the cylindrical surface of the second roller; The thread trimming execution device comprises a movable knife and a fixed knife; The second swing arm assembly also includes a pushing portion for pushing the movable knife to perform linear forward and backward motion.

2. A motor-driven thread trimming device for a sewing machine according to claim 1, characterized in that: The machine base comprises a first platform and a second platform, the motor driving device and the linkage device are fixed on the first platform, the driving shaft of the stepping motor is vertically fixed on the first platform, and the thread trimming actuator is fixed on the second platform.

3. A motor-driven thread trimming device for a sewing machine according to claim 2, characterized in that: The first rocker assembly further includes a first axial screw for axially rotating and fixing the first rocker on the first platform, and the second rocker assembly further includes a second axial screw for axially rotating and fixing the second rocker on the first platform.

4. The motor-driven thread trimming device of a sewing machine according to claim 1, characterized in that: The two ends of the connecting rod are respectively connected to the first swing rod and the second swing rod through a third axial screw and a fourth axial screw.

5. The motor-driven thread trimming device of a sewing machine according to claim 2, characterized in that: The pushing portion of the second swing rod assembly includes a fifth axial screw located at an end portion of the second swing rod.

6. A motor-driven thread trimming device for a sewing machine according to claim 5, characterized in that: A long groove extending along the linear forward and backward movement direction of the movable knife is provided on the second platform, and a sliding block is provided in the long groove. The sliding block can make linear forward and backward movement in the long groove; a sliding groove is provided on the sliding block, and the fifth axial screw can move in the sliding groove.

7. A motor-driven thread trimming device for a sewing machine according to claim 6, characterized in that: One end of the movable knife of the thread trimming actuator is fixed on a movable knife fixing block, and the movable knife fixing block is placed on the sliding block and can contact the end of the second swing rod.

8. The motor-driven thread trimming device of a sewing machine according to claim 7, characterized in that: A sliding portion extending along the linear forward and backward movement direction of the movable knife is provided on the movable knife fixing block; a movable knife guide seat extending along the linear forward and backward movement direction of the movable knife is provided on the second platform. When the movable knife of the thread trimming actuator moves linearly forward and backward, the sliding portion of the movable knife fixing block slides under the linear guidance of the movable knife guide seat.

9. The motor-driven thread trimming device for a sewing machine according to claim 8, characterized in that: The movable knife guide seat is arranged on one side of the long groove on the second platform, and a pressure plate is provided on the other side of the long groove, which is used to press the sliding block into the long groove, and the fifth axial screw of the second rocker arm assembly can abut against the side of the pressure plate during the process of linear forward and backward movement in the long groove.

10. The motor-driven thread trimming device for a sewing machine according to claim 8, characterized in that: One end of the fixed knife of the thread trimming actuator is fixed on a fixed knife fixing block, and the fixed knife fixing block is fixed on the second platform; the other end of the fixed knife is a fixed knife blade, and the other end of the movable knife is a movable knife blade. A spring sheet is provided below the movable knife blade for adjusting the distance between the movable knife blade and the fixed knife blade when the movable knife makes a linear motion and reaches the fixed knife blade, and the spring sheet is fixed on a spring adjustment platform.

11. A motor-driven thread trimming device for a sewing machine according to claim 10, characterized in that: The spring adjustment platform is fixed on the movable knife guide seat.

12. The motor-driven thread trimming device for a sewing machine according to claim 10, characterized in that: A movable knife auxiliary support plate is also provided between the movable knife blade of the movable knife and the spring sheet.

13. A motor-driven thread trimming device for a sewing machine according to claim 12, characterized in that: The movable knife auxiliary support plate is fixed on the movable knife guide seat.

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