Thread trimming device for a sewing machine

Abstract

The utility model relates to sewing machine technical field, concretely is a sewing machine thread trimming device. A sewing machine thread trimming device, including sewing machine main part and being located on the sewing machine main part's sewing platform, is equipped with sewing chamber and the cover plate that covers sewing chamber on the sewing platform, is equipped with the rotating hook mechanism in sewing chamber, is equipped with the tail swallow portion that separates one side line with the ground line on the rotating hook mechanism, is equipped with the fixed blade, the moving blade in sewing chamber, is equipped with the control computer on the sewing machine main part, is equipped with the sensor that detects the rotation angle with control computer signal connection on the pivot of rotating hook mechanism, sewing chamber still installs the moving knife drive arrangement that drives the moving blade and makes it with the fixed blade cooperation and cuts off the other side line and the ground line, is provided with the reset device on the moving knife drive arrangement, and the moving knife drive arrangement is connected with control computer signal.

Description

Technical Field

[0001] This utility model relates to the field of sewing machine technology, specifically a sewing machine thread cutting device. Background Technology

[0002] With the continuous development of technology, sewing machines are becoming increasingly automated. Most existing sewing machines are equipped with an automatic thread-cutting mechanism. After the fabric is put into the sewing machine and sewing begins, the automatic thread-cutting mechanism can be used to cut the thread and separate it from the fabric. This can save sewing time and reduce the labor intensity of sewing workers.

[0003] Currently, sewing machine thread-cutting devices on the market often employ a multi-stage linkage mechanism to achieve the thread-cutting function. Chinese patent disclosure (application publication number CN105908400A) describes a sewing machine function drive device and sewing machine, including a motor located within the machine head. The motor has a rotating shaft, which is horizontally positioned and perpendicular to the sewing machine's main shaft. The two ends of the rotating shaft are designated as end point one and end point two, both extending beyond the motor body. A cam component is fixed at one end point, and this cam component one drives the sewing machine's thread-cutting mechanism via a clutch mechanism. This multi-stage linkage structure involves multiple transmission components and complex connections, increasing manufacturing costs and assembly difficulty, and reducing the equipment's reliability and stability. Utility Model Content

[0004] To overcome the shortcomings mentioned above, this utility model aims to provide a technical solution that can solve the above problems.

[0005] A sewing machine thread-cutting device includes a sewing machine body and a sewing platform mounted on the sewing machine body. The sewing platform has a sewing chamber and a cover plate covering the sewing chamber. The sewing chamber has a rotary hook mechanism with a tail section that separates one side thread from the bobbin thread. The sewing chamber also has a fixed blade and a movable blade. The sewing machine body has a control computer. The rotating shaft of the rotary hook mechanism is equipped with a sensor that is connected to the control computer and detects the rotation angle. The sewing chamber also has a movable blade drive device that drives the movable blade to cooperate with the fixed blade to cut the other side thread and bobbin thread. The movable blade drive device is equipped with a reset device and is connected to the control computer.

[0006] Furthermore, the sensor is an encoder mounted on the shaft of the rotary shuttle mechanism.

[0007] Furthermore, the moving blade driving device includes a guide rod fixedly installed at the bottom of the cover plate, a slider slidably installed on the guide rod, and an electromagnet connected to the control computer signal. A driving rod passing through the electromagnet is fixedly connected to the slider, and an iron piece that can be attracted by the electromagnet is fixedly installed at the tail end of the driving rod. The reset device is a reset spring sleeved on the guide rod, and the moving blade is fixedly installed on the slider.

[0008] Furthermore, the moving blade is equipped with a wire-separating tip of a wire-protecting plate that further separates one side wire from the bottom wire, and a wire-cutting groove that works with the fixed blade to cut the other side wire and the bottom wire.

[0009] Furthermore, the moving blade has a protrusion on the edge of the cutting groove that cooperates with the fixed blade to squeeze and cut the other side line and bottom line.

[0010] Furthermore, the cover plate is provided with an installation groove, in which a fixed blade mounting block is installed. The bottom of the fixed blade mounting block is provided with a fixed blade groove, and the fixed blade is installed in the fixed blade groove.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model abandons the multi-level linkage structure and adopts the form of moving blade drive device directly driving moving blade, which reduces the number of transmission parts, reduces the manufacturing and assembly cost of the device, simplifies the equipment structure, and makes the overall layout more compact; reducing intermediate transmission parts reduces the failure rate caused by component matching errors, improves the reliability and stability of equipment operation, and extends the service life of the equipment.

[0012] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the main body of the sewing machine in this utility model.

[0015] Figure 2 This is a schematic diagram of the sewing chamber in this utility model.

[0016] Figure 3 This is a schematic diagram of the moving blade drive device in this utility model. Detailed Implementation

[0017] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0018] Please see Figures 1-3 A sewing machine thread trimming device includes a sewing machine body 1 and a sewing platform 2 mounted on the sewing machine body 1. The sewing platform 2 has a sewing chamber and a cover plate 3 covering the sewing chamber. A rotary shuttle mechanism 4 is provided inside the sewing chamber, and the rotary shuttle mechanism 4 has a tail section 41. The tail section 41 can separate one side thread from the bottom thread, providing convenient conditions for subsequent thread trimming operations.

[0019] The sewing chamber is equipped with a fixed blade 5 and a moving blade 6. A control computer (not shown) is mounted on the sewing machine body 1. A sensor (not shown) connected to the control computer (not shown) and detecting the rotation angle is mounted on the rotating shaft of the rotary hook mechanism 4. This sensor (not shown) is preferably an encoder mounted on the rotating shaft of the rotary hook mechanism 4. The encoder can accurately detect the rotation angle of the rotary hook mechanism 4 and feed the angle information back to the control computer (not shown) in real time, enabling the control computer (not shown) to accurately determine the thread-cutting timing based on the working state of the rotary hook mechanism 4.

[0020] The moving blade drive device 7 installed in the sewing chamber adopts a simple single-stage drive structure, including a guide rod 71 fixedly installed at the bottom of the cover plate 3, a slider 72 slidably installed on the guide rod 71, and an electromagnet 73 connected to the control computer (not shown). A drive rod 721 passing through the electromagnet 73 is fixedly connected to the slider 72. An iron piece 722 that can be attracted by the electromagnet 73 is fixedly installed at the tail end of the drive rod 721. The reset device is a reset spring 711 sleeved on the guide rod 71. The moving blade 6 is directly fixedly installed on the slider 72. Compared to multi-stage linkage structures, this single-stage drive structure reduces intermediate transmission components. When the control computer (not shown in the figure) issues a wire-cutting command, it directly controls the electromagnet 73 to be energized to generate magnetic attraction to the iron sheet 722, which drives the drive rod 721, slider 72, and moving blade 6 to move along the guide rod 71, so that the moving blade 6 cooperates with the fixed blade 5 to complete the wire-cutting operation. After the wire is cut, the electromagnet 73 is de-energized, and the return spring 711 pushes the slider 72 and the moving blade 6 to reset, reducing energy loss and improving the wire-cutting response speed.

[0021] The moving blade 6 is equipped with a wire-separating tip 61 and a wire-cutting groove 62. The wire-separating tip 61 can further separate the side wire from the bottom wire, ensuring clear stitches and facilitating wire cutting. The wire-cutting groove 62 cooperates with the fixed blade 5 to cut the other side wire and bottom wire. Furthermore, the moving blade 6 has a protrusion 63 on the edge of the wire-cutting groove 62. The protrusion 63 cooperates with the fixed blade 5 to squeeze and cut the other side wire and bottom wire. The protrusion 63 increases the shearing force between the moving blade 6 and the fixed blade 5, improving the wire cutting effect.

[0022] The cover plate 3 has a mounting groove 31, in which a fixed blade mounting block 8 is installed. The bottom of the fixed blade mounting block 8 has a fixed blade groove, in which the fixed blade 5 is installed. This installation method facilitates the installation and removal of the fixed blade 5, and makes it convenient to maintain and replace the fixed blade 5.

[0023] Specifically, after the sewing machine starts, the rotary hook mechanism 4 begins to work. The encoder detects the rotation angle of the rotary hook mechanism 4 in real time and transmits the angle information to the control computer (not shown in the figure). When the sewing machine finishes the last stitch, the top thread on the inside of the rotary hook mechanism 4 just separates from its tail 41, separating it from the bottom thread and the top thread on the other side. At this time, the sewing machine stops sewing. The control computer (not shown in the figure) sends an energizing command to the electromagnet 73 of the moving blade drive device 7. After the electromagnet 73 is energized, it generates magnetism and attracts the iron plate 722 at the tail end of the drive rod 721. This drives the drive rod 721, the slider 72, and the moving blade 6 fixed on the slider 72 to move along the guide rod 71 towards the fixed blade 5. The thread-separating tip 61 on the moving blade 6 further separates the top thread on the inside. The thread-cutting groove 62 on the moving blade 6 cooperates with the fixed blade 5. At the same time, the protrusion 63 on the edge of the thread-cutting groove 62 squeezes against the fixed blade 5, cutting off the top thread and the bottom thread on the other side. After the wire cutting is completed, the electromagnet 73 is de-energized and loses its magnetism. The reset spring 711, which is sleeved on the guide rod 71, pushes the slider 72 and the moving blade 6 to reset and return to the initial position, waiting for the next wire cutting command.

[0024] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

Claims

1. A thread-cutting device for a sewing machine, comprising a sewing machine body and a sewing platform disposed on the sewing machine body, the sewing platform having a sewing chamber and a cover plate covering the sewing chamber, the sewing chamber having a rotary hook mechanism, the rotary hook mechanism having a tail section for separating one side thread from the bottom thread, characterized in that, The sewing chamber contains a fixed blade and a moving blade. The sewing machine body is equipped with a control computer. The rotating shaft of the rotary hook mechanism is equipped with a sensor that is connected to the control computer and detects the rotation angle. The sewing chamber is also equipped with a moving blade drive device that drives the moving blade to cooperate with the fixed blade to cut the other side thread and the bottom thread. The moving blade drive device is equipped with a reset device and is connected to the control computer.

2. The sewing machine thread-cutting device according to claim 1, characterized in that, The sensor is an encoder mounted on the shaft of the rotary shuttle mechanism.

3. The sewing machine thread-cutting device according to claim 1, characterized in that, The moving blade drive device includes a guide rod fixedly installed at the bottom of the cover plate, a slider slidably installed on the guide rod, and an electromagnet connected to the control computer signal. A drive rod passing through the electromagnet is fixedly connected to the slider. An iron piece that can be attracted by the electromagnet is fixedly installed at the tail end of the drive rod. The reset device is a reset spring sleeved on the guide rod. The moving blade is fixedly installed on the slider.

4. A sewing machine thread-cutting device according to claim 1 or 3, characterized in that, The moving blade is equipped with a wire-separating tip of a wire-protecting plate that further separates one side line from the bottom line, and a wire-cutting groove that works with the fixed blade to cut the other side line and the bottom line.

5. The sewing machine thread-cutting device according to claim 4, characterized in that, The moving blade has a protrusion on the edge of the cutting groove that cooperates with the fixed blade to squeeze and cut the other side line and bottom line.

6. The sewing machine thread-cutting device according to claim 1, characterized in that, The cover plate is provided with a mounting groove, in which a fixed blade mounting block is installed. The bottom of the fixed blade mounting block is provided with a fixed blade groove, in which the fixed blade is installed.

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