Sewing machine and sewing method thereof

Abstract

The invention provides a sewing machine and a sewing method thereof, and belongs to the technical field of sewing equipment. The problem that an existing sewing machine is insufficient in sewing quality is solved. The sewing machine comprises a base, a needle plate with a needle falling hole, a bottom shuttle located below the needle plate, a straight-rod-shaped transmission rod and a strip-shaped thread shifting rod, the transmission rod is located on the side portion of the bottom shuttle and movably connected to the base, the end, close to the bottom shuttle, of the transmission rod is fixedly connected with one end of the thread shifting rod, and the other end of the transmission rod is connected with a thread shifting driving assembly. Under the driving of the thread shifting driving assembly, the transmission rod can perform reciprocating motion in the axial direction and swing at the same time, so that the other end of the thread shifting rod performs circumferential circulating motion and can be located between the needle falling hole and the bottom shuttle. Reverse stitches can be avoided in the sewing process, the sewing machine has the advantage of being low in manufacturing cost, and the sewing quality is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sewing equipment and relates to a sewing machine and a sewing method thereof. Background Art

[0002] As an indispensable equipment in the sewing industry such as clothing manufacturing, sewing machines have a history of hundreds of years. With the continuous development of industrial technology and the intensification of market competition, the clothing industry and other industries have put forward higher requirements for the automation, intelligence and efficiency of sewing equipment. In this context, computerized sewing machines such as template machines and pattern machines came into being.

[0003] The computer sewing machine is a product that combines traditional sewing technology with modern numerical control technology and automatic control technology. It mainly includes a base with a work surface, a machine head, a bottom shuttle, etc. The machine head is provided with a needle bar mechanism, and the work surface is provided with a feeding device for fixing the sewing material and driving the sewing material to move. When sewing, first input the sewing pattern into the computer sewing machine. After the sewing pattern is input, the numerical control system of the computer sewing machine will generate the needle point trajectory and the motion trajectory of the feeding device according to the pattern. After sewing starts, the feeding device will move along the motion trajectory with the sewing material, and the needle bar mechanism will drive the machine needle to perform the needle action at each needle point of the needle point trajectory, and cooperate with the bottom shuttle to interweave the upper thread and the lower thread, thereby realizing the sewing of the sewing material.

[0004] In traditional computer sewing machines, the orientation of the machine head and the bottom shuttle system is fixed, that is, the machine head and the bottom shuttle system do not rotate with the change of the cloth feeding direction. When this type of computer sewing machine is used to sew patterns, the sewing material will move horizontally in different directions with the feeding device, which will cause some of the stitches on the final sewing material to be like this: Figure 6 The positive trace (301 trace) shown, some are as follows Figure 7 The reverse stitch (319 stitch) shown. Since the forward stitch can usually ensure the beauty and consistency of sewing, in the occasions where the sewing quality is required to be high, such as sewing some high-end clothing and leather products, only the forward stitch can be used to sew the product. Therefore, in order to ensure the beauty of the product, it is necessary to avoid the reverse stitch on the product, and this type of computer sewing machine obviously cannot meet this demand.

[0005] In order to solve the above technical problems, the conventional technical means to solve the problem is to use a structure in which the machine head and the bottom shuttle system rotate in the sewing direction to avoid the occurrence of reverse stitches. For example, a template sewing machine with a machine head that can rotate and lift freely is disclosed in a Chinese patent document (authorization announcement number: CN207582086U), in which the upper machine head and the bottom line mechanism are synchronously rotated by a rotating motor arranged inside the machine head assembly through a synchronous belt, and a lifting mechanism for driving the upper machine head to lift and lower is also arranged between the upper machine head and the machine head assembly. The device can rotate in the feeding direction through the upper machine head and the bottom line mechanism, ensuring that the needle bar and the rotary shuttle can automatically adjust the direction according to the direction of the sewing pattern, thereby effectively avoiding the occurrence of reverse stitches.

[0006] Similar sewing machines, such as a template machine head with a rotatable needle bar (publication number: CN210368223U), a 360° infinitely rotatable head template machine (publication number: CN215051188U), and a head rotating template machine and sewing machine (publication number: CN221681367U) disclosed in Chinese patent documents, also use a structure in which the head and bottom shuttle system rotate in the sewing direction to avoid the appearance of reverse stitches during sewing. However, although this type of computer sewing solves the technical problem of ensuring uniform stitches, it still has the following shortcomings:

[0007] 1. The machine head and bottom shuttle system of the computer sewing machine rotate with the cloth feeding direction, which leads to a complex mechanism and high precision requirements. The complex mechanical structure is prone to cumulative errors, which leads to the phenomenon of rotation angle deviation or rotation synchronization deviation of the machine head and bottom shuttle system, thereby affecting the sewing accuracy and causing problems such as uneven stitches or skipped stitches. Therefore, the existing computer sewing machines still have problems with sewing quality and sewing aesthetics.

[0008] 2. The machine head and bottom shuttle system rotate in the sewing direction, which requires the addition of corresponding drive structure and transmission structure, and the mechanical structure of the machine head and bottom shuttle system will be more complicated, which will lead to an increase in sewing machine parts and a higher manufacturing cost of the sewing machine.

[0009] At present, in order to solve the problem of poor sewing quality caused by the rotation of the machine head and the bottom shuttle system following the sewing direction, the conventional technical means used by those skilled in the art are:

[0010] 1. In terms of manufacturing technology, high-precision processing technology is used to manufacture key components to improve the assembly accuracy and operation accuracy of the sewing mechanism, reduce error accumulation, and improve sewing quality.

[0011] 2. By optimizing the control algorithm, the synchronization between the machine head and the bottom shuttle can be improved and the error can be reduced.

[0012] 3. Use synchronous belt or synchronous gear transmission to ensure that the machine head and bottom shuttle system can rotate synchronously when the sewing direction changes, reduce the deviation of the rotation angle and improve the sewing quality. Summary of the invention

[0013] The purpose of the present invention is to solve the above problems in the prior art and to propose a sewing machine, which can avoid the occurrence of reverse stitches during the sewing process and solve the problem of insufficient sewing quality of the prior art sewing machines.

[0014] One of the objectives of the present invention is achieved through the following technical solutions: a sewing machine, comprising a base, a needle plate with a needle drop hole and a bottom shuttle located below the needle plate, characterized in that the sewing machine also includes a transmission rod and a thread shifting rod, the transmission rod is located on the side of the bottom shuttle and is movably connected to the base, one end of the transmission rod close to the bottom shuttle is fixedly connected to one end of the thread shifting rod, and the other end of the transmission rod is connected to a thread shifting drive assembly. Under the drive of the thread shifting drive assembly, the transmission rod can move back and forth axially and swing at the same time, so that the other end of the thread shifting rod makes a circumferential circulation motion and can be located between the needle drop hole and the bottom shuttle.

[0015] For sewing machines, the space between the bottom shuttle and the needle plate is very limited, and the transmission rod, as a transmission element that drives the thread-pushing lever, occupies a small space, which is convenient for its installation in the base and for axial reciprocating movement and swinging at the same time. By additionally arranging the thread-pushing lever on the transmission rod, it is ensured that the thread-pushing lever can smoothly move into the narrow space between the needle plate and the bottom shuttle to perform the thread-pushing action.

[0016] During the operation of the thread shifting drive assembly, the transmission rod can be driven to move back and forth axially and swing at the same time, so that the other end of the thread shifting rod can make a circumferential circulation motion and can be between the needle drop hole and the bottom shuttle. That is to say, during this movement, the other end of the thread shifting rod can pass through the gap between the needle drop hole and the bottom shuttle, thereby enabling the thread shifting rod to realize the thread shifting function and perform "stitch conversion".

[0017] Specifically, the principle of the thread lever in the sewing machine to achieve "stitch conversion" is:

[0018] When the sewing machine is used to sew patterns, the sewing material will move horizontally in different directions with the feeding device. When the sewing machine is sewing forward, it can sew forward stitches. When the feeding direction of the sewing material is changed to make the sewing machine perform reverse stitching, if the position of the bottom line between the bottom shuttle and the needle plate is not changed by the thread lever, the needle will be directly inserted normally, and reverse stitches will be formed. The reason is that after the bottom shuttle expands the upper thread loop and puts it on the bottom line, the needle needs to move upward. In this process, the upper thread on the needle will pass between the bottom line and the upper thread on the fabric and tighten upward. Finally, the upper thread and the bottom line are intertwined to form a "knot", that is, a reverse stitch.

[0019] In the present sewing machine, by setting a thread-shifting rod, when the sewing machine works in reverse sewing, the thread-shifting driving assembly starts to work, and drives the transmission rod to move before the needle is lowered. When the other end of the thread-shifting rod passes directly below the needle hole, the bottom line between the bottom shuttle and the needle plate is pushed, so that a part of the bottom line crosses the axis line where the needle is located, and then the needle is lowered again. When the needle moves downward to bring the upper thread under the needle plate, since the transmission rod also has an axial movement, the other end of the thread-shifting rod does not simply swing back and forth, but circumferentially circulates and thus has a stroke moving toward the side of the bottom shuttle, so that the other end of the thread-shifting rod can be separated from the bottom line after the needle is lowered. At this time, the bottom line cannot be reset to the initial position due to the obstruction of the needle, so that the upper thread is tightened by the needle upward, and the bottom line and the upper thread on the fabric are both on the same side of the upper thread on the needle, so that the upper thread on the needle no longer passes between the bottom line and the upper thread on the fabric for tightening, thereby avoiding the situation where the upper thread and the bottom line are "knotted", and finally forming a positive stitch with beautiful stitches. In addition, the thread puller is used to loosen the bottom thread, allowing the bottom shuttle to expand the surface thread loop, and the thread puller will not interfere with the process of putting it on the bottom thread.

[0020] Therefore, the sewing machine effectively avoids the generation of reverse stitches during sewing by adding a thread lever with a "stitch conversion" function. In addition, the design only needs to cooperate with the needle's needle action to control the transmission rod to move, without the need for the machine head and the bottom shuttle to rotate with the sewing direction, thereby eliminating the problem of reduced sewing quality caused by the deviation of the rotation angle or synchronization of the machine head and the bottom shuttle. Therefore, the design of the sewing machine not only reduces the control difficulty, but also significantly reduces the sewing error, further improving the sewing quality.

[0021] In the above-mentioned sewing machine, the transmission rod is in the shape of a straight rod and is arranged horizontally, the thread-shifting rod is formed by bending a metal strip, the thread-shifting rod is in the shape of an arc strip or a "Z"-shaped strip, and the thread-shifting rod is bent upward relative to the transmission rod. The thread-shifting rod is formed by bending a metal strip, which is not only convenient to manufacture, but also has a smaller diameter, which can be easily inserted into the narrow space between the needle plate and the bottom shuttle to perform the thread-shifting action. The straight-rod-shaped transmission rod is arranged horizontally, which is conducive to the installation and guidance of the transmission rod, ensures the good stability of the movement process of the transmission rod, and improves the thread-shifting accuracy of the thread-shifting rod. When the transmission rod moves to make the other end of the thread-shifting rod between the needle drop hole and the bottom shuttle, the thread-shifting rod will be close to the outer peripheral wall of the bottom shuttle, and the thread-shifting rod is in the shape of an arc strip or a "Z"-shaped strip, which is conducive to reducing the occupation of the thread-shifting rod near the bottom shuttle while realizing the thread-shifting function, thereby avoiding interference with components such as thread cutting, and the layout is more reasonable. At the same time, the thread-pushing lever is also bent upward relative to the transmission lever, so that the installation position of the transmission lever can be lowered, leaving enough installation space between the transmission lever and the work surface of the sewing machine, thereby facilitating the installation and movement of the transmission lever. Obviously, the shapes of the transmission lever and the thread-pushing lever in the sewing machine are not randomly selected, but are unconventional improvements made based on the realization of the bottom thread-pushing function of the sewing machine and the solution of the above-mentioned technical problems.

[0022] In the above-mentioned sewing machine, the rear side surface of the other end of the thread-shifting lever is inwardly concave so that the end of the thread-shifting lever forms a pointed shape, and the rear side surface of the end of the thread-shifting lever includes an arc-shaped inner concave surface and an avoidance slope 1 located outside the inner concave surface. When the sewing machine is working in reverse stitching, when the other end of the thread-shifting lever performs a circumferential circular motion, the bottom line between the bottom shuttle and the needle plate can slide over the avoidance slope 1 and smoothly slide into the inner concave surface, so that the thread-shifting lever can move with the bottom line, thereby smoothly bringing the bottom line to the other side of the needle axis, thereby realizing stitch conversion, so that the stitch formed by sewing is a positive stitch.

[0023] In the above-mentioned sewing machine, a second avoidance slope is provided on the front side surface of the other end of the thread-moving rod, and the swing amplitude of the transmission rod is smaller than the amplitude of the axial movement.

[0024] By setting the avoidance slope 2, the other end of the thread lever can effectively avoid the machine needle during movement, avoiding collision or interference with the machine needle. In addition, the design of the avoidance slope 2 allows the thread lever to have a smaller forward and backward swing, thereby shortening the swing stroke of the transmission rod. A smaller swing stroke means faster movement speed and higher efficiency, thus meeting the needs of high-speed sewing of the sewing machine. At the same time, making the axial movement of the transmission rod larger can ensure that the thread lever can smoothly detach from the bottom line, ensure that the bottom shuttle can smoothly hook the upper thread, and interweave with the bottom thread after expanding the upper thread loop, thereby improving the working stability and reliability of the sewing machine.

[0025] In the above-mentioned sewing machine, the thread driving assembly includes a rotating part that can rotate horizontally, the other end of the transmission rod is connected to a position on the rotating part that deviates from its rotation center, the base is provided with a guide frame located between the rotating part and the bottom shuttle and can swing horizontally, the guide frame is provided with a guide sleeve, and the middle section of the transmission rod is slidably inserted into the guide sleeve.

[0026] With this design, when the rotating part rotates, it can drive the transmission rod to move back and forth axially and swing at the same time, and the guide frame swings synchronously with the transmission rod. The guide frame is located between the rotating part and the bottom shuttle, so it can provide stable support and guidance for the transmission rod, preventing the transmission rod from offsetting or shaking during movement, so that the thread-shifting position of the thread-shifting rod connected to the transmission rod is accurate, avoiding the situation where the thread-shifting failure is caused by the action error. The setting of the guide sleeve can enhance the guiding effect, so that the transmission rod can move axially stably.

[0027] In the above-mentioned sewing machine, the thread driving assembly includes a rotating part that can rotate horizontally, the other end of the transmission rod is connected to a position on the rotating part that deviates from its rotation center, a guide groove is provided on the transmission rod along its axial direction, and a vertically arranged transmission shaft is fixedly connected to the base, and the transmission shaft slides through the guide groove.

[0028] The transmission shaft slides through the guide slot, constraining the movement of the transmission rod, so that when the rotating part rotates, it can drive the transmission rod to move back and forth axially and swing at the same time, and make the other end of the wire-pulling rod perform circumferential circulation motion.

[0029] In the above-mentioned sewing machine, the thread driving assembly also includes a motor with a vertically arranged rotating shaft, and the rotating member is a disc-shaped thread driving wheel, which is fixedly connected to the rotating shaft of the motor and concentrically arranged; or, the rotating member is in a bar shape, one end of the rotating member is fixedly connected to the rotating shaft of the motor, and the other end is rotatably connected to the other end of the transmission rod.

[0030] The design of the wire pulley can not only stably drive the transmission rod to move axially and swing, but also has the advantages of simple structure and small space occupation, so it is easy to install in the limited space of the seat body. The rotating part can also adopt a bar structure, which makes it easy to manufacture and low in cost, and can also stably drive the transmission rod to move back and forth axially and swing.

[0031] The second object of the present invention is achieved by the following technical scheme: a sewing method of a sewing machine, the sewing machine comprises a bottom shuttle, a needle plate with a needle drop hole and a feeding device for fixing the sewing material and driving the sewing material to move, the rotation center line of the bottom shuttle is horizontally arranged along the front and rear direction of the sewing machine, characterized in that the sewing machine also comprises a thread driving assembly, a transmission rod and a thread driving rod, one end of the thread driving rod is fixedly connected to the transmission rod, and the sewing method comprises the following steps:

[0032] A. The control system generates the needle point trajectory and the motion trajectory of the feeding device according to the sewing pattern;

[0033] B. The thread driving assembly drives the transmission rod to move, so that the other end of the thread driving rod moves from the front lower part of the needle drop hole to the rear lower part, pushing the bottom line between the bottom shuttle and the needle plate, and then the needle brings the upper thread to the bottom of the needle plate;

[0034] C. The thread-pulling drive assembly continues to drive the transmission rod to move, so that the other end of the thread-pulling rod moves toward the side of the bottom shuttle and detaches from the bottom thread between the bottom shuttle and the needle plate. Then the needle continues to move down to the lowest point and then moves up. The tip of the bottom shuttle moves to the back side of the needle and hooks the upper thread on the needle, interweaving the upper thread and the bottom thread to form a stitch.

[0035] D. The feeding device drives the sewing material to the next stitch sewing position according to the motion trajectory;

[0036] E. Repeat steps B to D and sew according to the needle point trajectory obtained from the sewing pattern.

[0037] The sewing method is applicable to a sewing machine in which the tip of the bottom shuttle hooks the thread behind the needle, wherein the bottom shuttle can be a rotary shuttle in the prior art or a swing shuttle in the prior art. In step B, when the sewing machine is working in reverse sewing, the thread shifting drive assembly starts to work, and before the needle goes down, the transmission rod is driven to move, so that the other end of the thread shifting rod moves from the front lower part of the needle drop hole to the rear lower part, and when passing directly below the needle drop hole, the bottom line between the bottom shuttle and the needle plate is pushed, so that a part of the bottom line crosses the axis line where the needle is located, and then the needle goes down again. When the needle moves downward to bring the upper thread under the needle plate, in step C, since the transmission rod also has an axial movement, the other end of the thread lever does not simply swing back and forth, but circulates in a circular motion and thus has a travel toward the side of the bottom shuttle, so that the other end of the thread lever can be separated from the bottom line after the needle is inserted. At this time, the bottom line cannot be reset to the initial position due to the obstruction of the needle, so that the upper thread moves upward with the needle to tighten, and the bottom line and the upper thread on the fabric are on the same side of the upper thread on the needle. In this way, the upper thread on the needle no longer passes between the bottom line and the upper thread on the fabric for tightening, thereby avoiding the situation where the upper thread and the bottom line are "knotted", and finally forming a positive stitch with beautiful stitches. In addition, the bottom line is loosened by the thread lever, so that the bottom shuttle expands the upper thread loop, and will not be interfered by the thread lever in the process of being put on the bottom line.

[0038] In the sewing method of the sewing machine described above, in step C, during the process of the needle moving from the lowest point to the highest point, the thread shifting drive assembly continues to drive the transmission rod to move, and the other end of the thread shifting rod returns to the front and lower part of the needle drop hole. When the thread shifting rod performs the thread shifting action, its starting point is located in the front and lower part of the needle drop hole. Therefore, during the process of the needle moving up to the highest point, the thread shifting rod synchronously moves to return the other end of the thread shifting rod to the front and lower part of the needle drop hole. This design allows the thread shifting rod to immediately perform the thread shifting action without the need for additional left and right movements when the thread needs to be shifted again, thereby shortening the preparation time for the thread shifting process and satisfying the sewing needs of the sewing machine for fast needle placement.

[0039] The third object of the present invention is achieved by the following technical scheme: a sewing method of a sewing machine, the sewing machine comprises a bottom shuttle, a needle plate with a needle drop hole and a feeding device for fixing the sewing material and driving the sewing material to move, the rotation center line of the bottom shuttle is horizontally arranged along the front and rear direction of the sewing machine, characterized in that the sewing machine also comprises a thread driving assembly, a transmission rod and a thread lever, one end of the thread lever is fixedly connected to the transmission rod, and the sewing method comprises the following steps:

[0040] A. The control system generates the needle point trajectory and the motion trajectory of the feeding device according to the sewing pattern;

[0041] B. The thread driving assembly drives the transmission rod to move, so that the other end of the thread driving rod moves from the lower rear of the needle drop hole to the lower front, pushing the bottom line between the bottom shuttle and the needle plate, and then the needle brings the upper thread to the bottom of the needle plate;

[0042] C. The thread driving assembly continues to drive the transmission rod to move, so that the other end of the thread driving rod moves toward the side of the bottom shuttle and detaches from the bottom line between the bottom shuttle and the needle plate. Then the needle continues to move down to the lowest point and then moves up. The tip of the bottom shuttle moves to the front side of the needle and hooks the upper thread on the needle, interweaving the upper thread and the bottom thread to form a stitch.

[0043] D. The feeding device drives the sewing material to the next stitch sewing position according to the motion trajectory;

[0044] E. Repeat steps B to D and sew according to the needle point trajectory obtained from the sewing pattern.

[0045] The sewing method is applicable to a sewing machine in which the tip of the bottom shuttle hooks the thread in front of the needle, wherein the bottom shuttle can be a rotary shuttle in the prior art. The working principle of the present sewing method is similar to that of the above sewing method, except that the reverse stitch area a of the sewing machine is different due to the different thread hooking positions of the bottom shuttle, so the thread lever needs to move in different directions to achieve "stitch conversion".

[0046] In step B of the thread shifting method, when the sewing machine is working in reverse stitching, the thread shifting drive assembly starts to work, and before the needle goes down, it drives the transmission rod to move, so that the other end of the thread shifting rod moves from the rear lower part of the needle drop hole to the front lower part, and when the other end of the thread shifting rod passes directly below the needle drop hole, it pushes the bottom line between the bottom shuttle and the needle plate, so that a part of the bottom line crosses the axis line where the needle is located, and then the needle goes down again. When the needle moves downward to bring the upper thread under the needle plate, in step C, the other end of the thread shifting rod can be separated from the bottom line after the needle goes down. At this time, the bottom line cannot be reset to the initial position due to the obstruction of the needle, so that the upper thread is in the process of being tightened by the random needle moving upward. The bottom line and the upper thread on the fabric are both on the same side of the upper thread on the needle, so that the upper thread on the needle no longer passes between the bottom line and the upper thread on the fabric for tightening, thereby avoiding the situation where the upper thread and the bottom line are "knotted", and finally forming a positive stitch with beautiful stitches. In addition, the thread puller is used to loosen the bottom thread, allowing the bottom shuttle to expand the surface thread loop, and the thread puller will not interfere with the process of putting it on the bottom thread.

[0047] Compared with the prior art, the sewing machine and the sewing method have the following advantages:

[0048] 1. In this sewing machine, by adding a thread lever, the thread lever has the function of "stitch conversion", which can avoid the appearance of reverse stitches during sewing, ensure the beauty and consistency of sewing, and make the computer sewing machine well applied to sewing some high-end clothing, leather products and other occasions with high sewing quality requirements.

[0049] 2. This sewing machine only needs to coordinate with the needle's lowering action to control the transmission rod to make the thread lever move back and forth above the bottom shuttle, without the need for the machine head and the bottom shuttle to rotate with the sewing direction, thus eliminating the problem of reduced sewing quality caused by the deviation of the rotation angle or synchronization of the machine head and the bottom shuttle. Therefore, the design of this computer sewing machine not only reduces the control difficulty, but also significantly reduces the sewing error, further improving the sewing quality.

[0050] 3. Since in this computer sewing machine, the machine head and the bottom shuttle only need to maintain a constant direction for sewing, the structure of the sewing machine is simplified and the manufacturing cost is significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a top view of the bottom shuttle in the first embodiment.

[0052] Figure 2 It is a partial structural schematic diagram of the first embodiment of the sewing machine.

[0053] Figure 3 It is an enlarged view of the bottom shuttle part in the first embodiment.

[0054] Figure 4 It is a structural schematic diagram of the wire-pushing lever, the transmission shaft and the wire-pushing drive assembly in the first embodiment.

[0055] Figure 5 It is a partial cross-sectional view of the wire-shifting lever and the transmission shaft in the first embodiment.

[0056] Figure 6 This is a schematic diagram of the forward trace (301 trace).

[0057] Figure 7 This is a schematic diagram of the reverse stitch (319 stitch).

[0058] Figure 8 This is the sewing process diagram Figure 1 .

[0059] Fig. 9 It is a schematic diagram of the principle of forming reverse stitches.

[0060] Fig.10 This is the sewing process diagram Figure 2 .

[0061] Fig.11 It is a schematic diagram of the thread-shifting rod driving the bottom line to move in the first embodiment and the fourth embodiment.

[0062] Fig.12 It is a schematic diagram of the stitch area of ​​the sewing machine in the fifth embodiment.

[0063] Fig.13 It is a structural schematic diagram of the wire-pushing lever, the transmission shaft and the wire-pushing drive assembly in the second embodiment.

[0064] Fig.14 It is a structural schematic diagram of the wire-pulling rod in the third embodiment.

[0065] Fig.15 It is a top view of the other end of the wire-pulling rod in the third embodiment.

[0066] In the figure, 1. base; 2. needle plate; 21. needle drop hole; 3. bottom shuttle; 31. shuttle tip; 32. thread outlet; 4. transmission rod; 41. guide slide; 5. thread shifting rod; 51. inner concave surface; 52. avoidance slope 1; 53. avoidance slope 2; 6. thread shifting drive assembly; 61. rotating part; 62. motor; 63. transmission joint; 7. guide frame; 8. guide sleeve; 9. transmission shaft; 10. needle. DETAILED DESCRIPTION

[0067] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0068] Embodiment 1

[0069] like Figures 1 to 4 As shown, the sewing machine includes a base 1, a needle plate 2 with a needle drop hole 21, and a bottom shuttle 3 located below the needle plate 2. The bottom shuttle 3 has a shuttle tip 31 and a thread outlet 32. The rotation center line of the bottom shuttle 3 is horizontally arranged along the front and rear direction of the sewing machine. Further, the sewing machine also includes a straight rod-shaped transmission rod 4, a strip-shaped thread-shifting rod 5, and a feeding device for fixing the sewing material and driving the sewing material to move. Among them, the transmission rod 4 is horizontally arranged, the thread-shifting rod 5 is formed by bending a metal strip, and the diameter of the thread-shifting rod 5 is smaller than the diameter of the transmission rod 4. The transmission rod 4 is located at the side of the bottom shuttle 3 and is movably connected to the base 1. One end of the transmission rod 4 close to the bottom shuttle 3 is fixedly connected to one end of the thread-pulling rod 5 and the thread-pulling rod 5 is bent upward relative to the transmission rod 4. The other end of the transmission rod 4 is connected to the thread-pulling driving assembly 6. Under the drive of the thread-pulling driving assembly 6, the transmission rod 4 can reciprocate axially in the horizontal plane and swing at the same time, so that the other end of the thread-pulling rod 5 performs circumferential circulation and can be located between the needle drop hole 21 and the bottom shuttle 3. In addition, the swinging amplitude of the transmission rod 4 is smaller than the amplitude of the axial movement.

[0070] like Figure 1As shown, in the present sewing machine, the plane where the axis line of the bottom shuttle 3 and the needle 10 of the sewing machine coexist is the critical plane A, the line connecting the thread outlet 32 ​​of the bottom shuttle 3 and the needle drop hole 21 is inclined and the vertical plane where the line is located is the critical plane B, when the shuttle tip 31 of the bottom shuttle 3 moves to the needle 10, the area between the side of the critical plane A facing away from the thread outlet 32 ​​and the side of the critical plane B facing away from the shuttle tip 31 is the reverse stitch area a, and the remaining area is the forward stitch area b.

[0071] like Figure 2 and Figure 4 As shown, the thread-moving rod 5 is in an arc-shaped strip shape. When the transmission rod 4 moves to make the other end of the thread-moving rod 5 between the needle drop hole 21 and the bottom shuttle 3, the thread-moving rod 5 will be close to the outer peripheral wall of the bottom shuttle 3, and the front side surface of the other end of the thread-moving rod 5 has a second avoidance slope 53. The front side of the other end of the thread-moving rod 5 is provided with a second avoidance slope 53, so that the thread-moving rod 5 can effectively avoid the machine needle 10 during the movement, avoiding collision or interference with the machine needle 10.

[0072] like Figure 4 and Figure 5 As shown, the wire-pulling drive assembly 6 includes a motor 62 with a vertically arranged shaft and a rotating member 61 capable of horizontal rotation. The other end of the transmission rod 4 is connected to a position on the rotating member 61 deviating from its rotation center. The base 1 is provided with a guide frame 7 located between the rotating member 61 and the bottom shuttle 3 and capable of horizontal swinging. The guide frame 7 is provided with a guide sleeve 8, and the middle section of the transmission rod 4 is slidably inserted into the guide sleeve 8. Among them, the rotating member 61 is a disc-shaped wire-pulling wheel, which is fixedly connected to the shaft of the motor 62 and is concentrically arranged. The other end of the transmission rod 4 is rotatably connected to the eccentric position of the wire-pulling wheel through a transmission joint 63.

[0073] Embodiment 2

[0074] The structure and principle of this embodiment are basically the same as those of the first embodiment, except that: Fig.13 As shown, the wire-dial drive assembly 6 includes a rotating member 61 that can rotate horizontally. The rotating member 61 is in a bar shape. One end of the rotating member 61 is fixedly connected to the rotating shaft of the motor 62, and the other end is rotatably connected to the other end of the transmission rod 4.

[0075] A guide slot 41 is provided on the transmission rod 4 along its axial direction, and a vertically arranged transmission shaft 9 is fixedly connected to the base 1, and the transmission shaft 9 is slidably inserted into the guide slot 41. The transmission shaft 9 is slidably inserted into the guide slot 41, constraining the movement of the transmission rod 4, so that when the rotating member 61 rotates, the transmission rod 4 can be driven to axially reciprocate and swing at the same time, and the other end of the wire-pulling rod 5 can perform circumferential circulation motion.

[0076] Embodiment 3

[0077] The structure and principle of this embodiment are basically the same as those of the first embodiment, except that: Fig.14 and Fig.15 As shown, the dial lever 5 is in a "Z"-shaped strip, and the rear side surface of the other end is also concave inward so that the end of the dial lever 5 forms a pointed shape, and the rear side surface of the pointed end includes an arc-shaped inner concave surface 51 and an avoidance slope 52 located outside the inner concave surface 51.

[0078] When the sewing machine is working in reverse sewing and the other end of the thread shifting rod 5 makes a circumferential circulation motion, the bottom line between the bottom shuttle 3 and the needle plate 2 can slide over the avoidance slope 52 and smoothly slide into the inner concave surface 51, so that the thread shifting rod 5 can move with the bottom line, and in the process of the thread shifting rod 5 retracting away from the bottom shuttle 3, the side of the inner concave surface 51 close to the avoidance slope 52 can also move a certain distance with the bottom line. After the needle 10 brings the surface thread to the bottom of the needle plate 2, the thread shifting rod 5 is separated from the bottom line again, so that the bottom line can be brought to the other side of the axis of the needle 10 more smoothly, thereby realizing the stitch conversion and making the stitch formed by sewing a forward stitch.

[0079] Embodiment 4

[0080] The present embodiment relates to a sewing method for a sewing machine, which is suitable for a sewing machine in which the shuttle tip 31 of the bottom shuttle 3 hooks the thread behind the needle 10, and the stitch area is as follows: Figure 1 Wherein, the bottom shuttle 3 can be a rotary shuttle in the prior art, and can also be a swing shuttle in the prior art.

[0081] Specifically, the sewing method comprises the following steps:

[0082] A. The control system generates the needle point trajectory and the motion trajectory of the feeding device according to the sewing pattern;

[0083] B. The thread driving assembly 6 drives the transmission rod 4 to move, so that the other end of the thread driving rod 5 moves from the front lower part to the rear lower part of the needle drop hole 21, pushing the bottom line between the bottom shuttle 3 and the needle plate 2, and then the needle 10 brings the upper thread to the lower part of the needle plate 2;

[0084] C. The thread shifting drive assembly 6 continues to drive the transmission rod 4 to move, so that the other end of the thread shifting rod 5 moves toward the side of the bottom shuttle 3 and disengages from the bottom line between the bottom shuttle 3 and the needle plate 2. Then, the needle 10 continues to move down to the lowest point and then moves up. The shuttle tip 31 of the bottom shuttle 3 moves to the rear side of the needle 10 to hook the upper thread on the needle 10, and the upper thread and the bottom thread are interwoven to form a stitch. In the process of the needle 10 moving from the lowest point to the highest point, the other end of the thread shifting rod 5 returns to the front and lower part of the needle drop hole 21.

[0085] D. The feeding device drives the sewing material to the next stitch sewing position according to the motion trajectory;

[0086] E. Repeat steps B to D and sew according to the needle point trajectory obtained from the sewing pattern.

[0087] The following is an example of a sewing machine in which the shuttle tip 31 of the bottom shuttle 3 hooks the thread at the rear side of the needle 10, and describes the working principle of the sewing machine in conjunction with the accompanying drawings:

[0088] For a certain sewing machine or the same model, since the structure (including the type of the bottom shuttle 3, the installation position, the thread hooking direction, the position of the thread outlet 32, and the position of the needle 10) is determined, its critical surface A and critical surface B are determined, and the reverse stitch area a and the forward stitch area b are also determined.

[0089] During the operation of the sewing machine, when the feeding device moves to the positive stitch area b to feed the material, the sewing machine is in the positive sewing working state. At this time, the needle 10 moves up with the upper thread, and in the process of tightening the upper thread, as shown in FIG. Figure 8 As shown, the bottom line between the bottom shuttle 3 and the needle plate 2 and the upper line on the fabric are both located on the same side of the upper line on the needle 10, so that Figure 6 Forward trace (i.e. 301 trace) shown.

[0090] When the feeding device moves to the reverse stitch area b for feeding, the sewing machine is in the reverse stitching working state. At this time, if the thread lever 5 is not used to change the position of the bottom line between the bottom shuttle 3 and the needle plate 2, the needle 10 will be directly inserted normally, and a reverse stitch will be formed at this time. The reason is: Fig. 9 As shown in FIG. 1 , after the bottom shuttle 3 expands the upper thread loop and puts it on the bottom thread, the needle 10 needs to move up. During this process, the upper thread on the needle 10 passes between the bottom thread and the upper thread on the fabric and tightens upward. Finally, the upper thread and the bottom thread are intertwined to form a "knot", that is, a knot is formed as shown in FIG. Figure 7 Reverse stitch (i.e. 319 stitch) shown.

[0091] In the present sewing machine, by adding the thread-pushing lever 5, before the needle 10 is lowered, the other end of the thread-pushing lever 5 can be moved from the front lower part of the needle hole 21 to the rear lower part, and when passing directly below the needle hole 21, the bottom thread between the bottom shuttle 3 and the needle plate 2 is pushed, so that a part of the bottom thread crosses the axis of the needle 10 and moves to the positive stitch area b, and then the needle 10 can be lowered. Fig.11 , you can clearly understand the state before and after the thread lever 5 drives the bottom line to move, Fig.11In the figure, the thick solid line T represents the position of the bottom line between the bottom shuttle 3 and the needle plate 2 when the thread shifting lever 5 has not performed the thread shifting action. The thin solid line t represents the position of the bottom line between the bottom shuttle 3 and the needle plate 2 after the thread shifting lever 5 has performed the thread shifting action. It can be seen from the thin solid line t that a part of the bottom line has crossed the axis line where the needle 10 is located and moved to the positive stitch area b. When the needle 10 moves downward to bring the upper thread under the needle plate 2, the thread shifting lever 5 is separated from the bottom line. At this time, the bottom line can no longer be reset to its initial position due to the obstruction of the needle 10. In this way, the upper thread is tightened as the needle 10 moves upward. Fig.10 As shown, the bottom line and the upper line on the fabric are both located on the same side of the upper line on the needle 10, so that the upper line on the needle 10 is no longer Fig. 9 The thread is tightened by passing it between the bottom thread and the upper thread on the fabric to avoid the upper thread and the bottom thread from becoming tangled. Figure 6 Forward trace shown.

[0092] Embodiment 5

[0093] This embodiment relates to a sewing method for a sewing machine, which is suitable for a sewing machine in which the shuttle tip 31 of the bottom shuttle 3 hooks the thread on the front side of the needle 10, and the stitch area is as follows: Fig.12 shown.

[0094] The sewing method comprises the following steps:

[0095] A. The control system generates the needle point trajectory and the motion trajectory of the feeding device according to the sewing pattern;

[0096] B. The thread driving assembly 6 drives the transmission rod 4 to move, so that the other end of the thread driving rod 5 moves from the rear lower part to the front lower part of the needle drop hole 21, pushing the bottom line between the bottom shuttle 3 and the needle plate 2, and then the needle 10 brings the upper thread to the bottom of the needle plate 2;

[0097] C. The thread driving assembly 6 continues to drive the transmission rod 4 to move, so that the other end of the thread driving rod 5 moves toward the side of the bottom shuttle 3 and detaches from the bottom line between the bottom shuttle 3 and the needle plate 2. Then, the needle 10 continues to move down to the lowest point and then moves up. The shuttle tip 31 of the bottom shuttle 3 moves to the front side of the needle 10 and hooks the upper thread on the needle 10, interweaving the upper thread and the bottom thread to form a stitch.

[0098] D. The feeding device drives the sewing material to the next stitch sewing position according to the motion trajectory;

[0099] E. Repeat steps B to D and sew according to the needle point trajectory obtained from the sewing pattern.

[0100] The working principle of this sewing method is similar to that of the sewing method in the fourth embodiment, except that the thread hooking position of the bottom shuttle 3 is different. Fig.12As shown, the direction of the reverse stitch area a of the sewing machine is different from that in Example 4, so the thread lever 5 needs to be moved in the opposite direction to push the bottom line between the bottom shuttle 3 and the needle plate 2 to the forward stitch area b when the sewing machine is in reverse sewing operation, thereby realizing "stitch conversion" and ensuring that forward stitches are formed during the sewing process.

[0101] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0102] Although this article uses more terms such as 1, base; 2, needle plate; 21, needle drop hole; 3, bottom shuttle; 31, shuttle tip; 32, thread outlet; 4, transmission rod; 41, guide slide; 5, thread-pulling rod; 51, inner concave surface; 52, avoidance slope 1; 53, avoidance slope 2; 6, thread-pulling drive assembly; 61, rotating part; 62, motor; 63, transmission joint; 7, guide frame; 8, guide sleeve; 9, transmission shaft; 10, needle, etc., it does not exclude the possibility of using other terms. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A sewing machine, comprising a base (1), a needle plate (2) having a needle drop hole (21), and a bottom shuttle (3) located below the needle plate (2), characterized in that: The sewing machine further comprises a transmission rod (4) and a thread-moving rod (5), wherein the transmission rod (4) is located at the side of the bottom shuttle (3) and is movably connected to the base (1), one end of the transmission rod (4) close to the bottom shuttle (3) is fixedly connected to one end of the thread-moving rod (5), and the other end of the transmission rod (4) is connected to a thread-moving driving assembly (6). Under the drive of the thread-moving driving assembly (6), the transmission rod (4) can reciprocate along the axial direction and swing at the same time, so that the other end of the thread-moving rod (5) can perform circumferential circulation motion and can be located between the needle drop hole (21) and the bottom shuttle (3).

2. The sewing machine according to claim 1, characterized in that: The transmission rod (4) is in the shape of a straight rod and is arranged horizontally. The wire-pushing rod (5) is formed by bending a metal strip. The wire-pushing rod (5) is in the shape of an arc strip or a "Z"-shaped strip, and the wire-pushing rod (5) is bent upward relative to the transmission rod (4).

3. The sewing machine according to claim 1 or 2, characterized in that: The rear side surface of the other end of the dialing rod (5) is concave inwardly so that the end of the dialing rod (5) forms a pointed shape, and the rear side surface of the end of the dialing rod (5) comprises an arc-shaped inner concave surface (51) and an avoidance inclined surface (52) located outside the inner concave surface (51).

4. The sewing machine according to claim 1 or 2, characterized in that: A second avoidance slope (53) is provided on the front side surface of the other end of the wire-drifting rod (5), and the swing amplitude of the transmission rod (4) is smaller than the amplitude of the axial movement.

5. The sewing machine according to claim 1 or 2, characterized in that: The wire-pulling drive assembly (6) comprises a rotating member (61) capable of horizontal rotation, the other end of the transmission rod (4) being connected to a position on the rotating member (61) deviating from its rotation center, the base (1) further comprising a guide frame (7) located between the rotating member (61) and the bottom shuttle (3) and capable of horizontal swinging, the guide frame (7) being provided with a guide sleeve (8), and the middle section of the transmission rod (4) being slidably inserted into the guide sleeve (8).

6. The sewing machine according to claim 1 or 2, characterized in that: The wire-pulling drive assembly (6) comprises a rotating member (61) capable of horizontal rotation, the other end of the transmission rod (4) being connected to a position on the rotating member (61) deviating from its rotation center, the transmission rod (4) being provided with a guide slot (41) along its axial direction, and the base (1) being fixedly connected with a vertically arranged transmission shaft (9), the transmission shaft (9) being slidably arranged in the guide slot (41).

7. The sewing machine according to claim 5, characterized in that The wire-pulling drive assembly (6) further comprises a motor (62) with a vertically arranged shaft, and the rotating member (61) is a disc-shaped wire-pulling wheel, which is fixedly connected to the shaft of the motor (62) and is arranged concentrically; or, the rotating member (61) is in the shape of a strip, one end of the rotating member (61) is fixedly connected to the shaft of the motor (62), and the other end is rotatably connected to the other end of the transmission rod (4).

8. A sewing method for a sewing machine, the sewing machine comprising a bottom shuttle (3), a needle plate (2) having a needle drop hole (21), and a feeding device for fixing sewing materials and driving the sewing materials to move, the rotation center line of the bottom shuttle (3) being arranged horizontally along the front-rear direction of the sewing machine, characterized in that: The sewing machine further comprises a thread-driving drive assembly (6), a transmission rod (4) and a thread-driving rod (5), one end of the thread-driving rod (5) being fixedly connected to the transmission rod (4). The sewing method comprises the following steps: A. The control system generates the needle point trajectory and the motion trajectory of the feeding device according to the sewing pattern; B. The thread driving assembly (6) drives the transmission rod (4) to move, so that the other end of the thread driving rod (5) moves from the front lower part of the needle drop hole (21) to the rear lower part, pushing the bottom thread between the bottom shuttle (3) and the needle plate (2), and then the needle (10) brings the upper thread to the lower part of the needle plate (2); C. The thread-pulling drive assembly (6) continues to drive the transmission rod (4) to move, so that the other end of the thread-pulling rod (5) moves toward the side of the bottom shuttle (3) and detaches from the bottom thread between the bottom shuttle (3) and the needle plate (2), and then the machine needle (10) continues to move down to the lowest point and then moves up, and the shuttle tip (31) of the bottom shuttle (3) moves to the rear side of the machine needle (10) to hook the upper thread on the machine needle (10), and the upper thread and the bottom thread are interwoven to form a stitch; D. The feeding device drives the sewing material to the next stitch sewing position according to the motion trajectory; E. Repeat steps B to D and sew according to the needle point trajectory obtained from the sewing pattern.

9. The sewing method for a sewing machine according to claim 8, characterized in that: In step C, during the process of the needle (10) moving from the lowest point to the highest point, the thread-moving drive assembly (6) continues to drive the transmission rod (4) to move, so that the other end of the thread-moving rod (5) returns to the front lower part of the needle drop hole (21).

10. A sewing method for a sewing machine, the sewing machine comprising a bottom shuttle (3), a needle plate (2) having a needle drop hole (21), and a feeding device for fixing sewing materials and driving the sewing materials to move, the rotation center line of the bottom shuttle (3) being arranged horizontally along the front-rear direction of the sewing machine, characterized in that: The sewing machine further comprises a thread-driving drive assembly (6), a transmission rod (4) and a thread-driving rod (5), one end of the thread-driving rod (5) being fixedly connected to the transmission rod (4). The sewing method comprises the following steps: A. The control system generates the needle point trajectory and the motion trajectory of the feeding device according to the sewing pattern; B. The thread driving assembly (6) drives the transmission rod (4) to move, so that the other end of the thread driving rod (5) moves from the lower rear portion of the needle drop hole (21) to the lower front portion, pushing the lower thread between the bottom shuttle (3) and the needle plate (2), and then the needle (10) brings the upper thread to the lower portion of the needle plate (2); C. The thread-pulling drive assembly (6) continues to drive the transmission rod (4) to move, so that the other end of the thread-pulling rod (5) moves toward the side of the bottom shuttle (3) and detaches from the bottom thread between the bottom shuttle (3) and the needle plate (2), and then the needle (10) continues to move down to the lowest point and then moves up, and the shuttle tip (31) of the bottom shuttle (3) moves to the front side of the needle (10) to hook the upper thread on the needle (10), and the upper thread and the bottom thread are interwoven to form a stitch; D. The feeding device drives the sewing material to the next stitch sewing position according to the motion trajectory; E. Repeat steps B to D and sew according to the needle point trajectory obtained from the sewing pattern.

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