Sewing machine

Abstract

The utility model provides a sewing machine, 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 rotating shuttle located below the needle plate, a thread shifting rod and a rotating piece capable of horizontally rotating, a guide piece located on the side portion of the rotating shuttle and capable of horizontally swinging is arranged on the base, the thread shifting rod comprises a rod body and an arc-strip-shaped thread shifting head, and the rod body is connected to the guide piece in a sliding mode in the axial direction of the rod body. One end of the thread pulling head is fixedly connected to the end, close to the rotating shuttle, of the rod body and bent upwards relative to the rod body, the other end of the rod body is rotationally connected to the position, deviating from the rotating center of the rotating piece, of the rotating piece, and when the rotating piece drives the rod body to move, the other end of the thread pulling head can be located between the needle falling hole and the rotating shuttle. According to the utility model, the sewing quality is further improved, and the manufacturing cost is obviously reduced on the basis.

Description

TECHNICAL FIELD

[0001] The utility model belongs to sewing equipment technical field relates to a sewing machine. BACKGROUND

[0002] The sewing machine as the indispensable equipment of the sewing industry such as clothing manufacturing, its development course has hundreds of years. Along with the continuous development of industrial technology and the intensification of market competition, the clothing industry etc. have put forward higher requirements to the automation, intelligentization and high efficiency of sewing equipment. Under this background, the computer sewing machine such as template machine, pattern machine arises at the historic moment.

[0003] The computer sewing machine is the product that combines traditional sewing technology with modern numerical control technology and automation control technology, and it mainly includes base with workbench, machine head, rotating shuttle, etc. The needle bar mechanism is arranged on the machine head, and the feeding device for fixing and driving the sewing material to move is arranged on the workbench. During sewing, the sewing pattern is first input into the computer sewing machine, and after the input of the sewing pattern, the numerical control system of the computer sewing machine will generate the needle point track and the movement track of the feeding device according to the pattern. After the sewing starts, the feeding device will move with the sewing material according to the movement track, the needle bar mechanism will drive the needle to perform the needle-down action at each needle point of the needle point track, and the rotating shuttle will cooperate to interweave the top thread and the bottom thread, so as to realize the sewing of the sewing material.

[0004] In the traditional computer sewing machine, 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 pattern, since the sewing material will move horizontally in different directions with the feeding device, it will cause that some of the stitches formed on the final sewing material are forward stitches (301 stitches) as shown in Figure 6 , and some are reverse stitches (319 stitches) as shown in Figure 7 . Since the forward stitch can usually ensure the beauty and consistency of sewing, in some occasions where high-end clothing, leather products and other occasions with high requirements on sewing quality, only forward stitches can be used for sewing products, therefore, in order to ensure the beauty of the product, it is necessary to avoid the appearance of reverse stitches on the product, and this type of computer sewing machine obviously cannot meet this demand.

[0005] To solve the above technical problems, the current conventional technical means is to adopt the structure that the machine head and the bottom shuttle system follow the sewing direction to rotate, so as to avoid the appearance of reverse stitches. For example, a machine head freely rotatable and liftable template sewing machine (authorized publication number: CN207582086U) disclosed in Chinese patent literature, the machine head and the bottom line mechanism are realized synchronous rotation by a synchronous belt through a rotary motor arranged in the machine head assembly, and a lifting mechanism for driving the machine head to lift is arranged between the machine head and the machine head assembly. The device can rotate along with the feeding direction through the machine head and the bottom line mechanism, ensuring that the needle bar and the rotating shuttle can automatically adjust the direction according to the direction of the sewing pattern, so as to effectively avoid the appearance of reverse stitches.

[0006] Similarly, the sewing machine, such as a needle bar rotatable template machine head (publication number: CN210368223U), a 360° infinite rotation head template machine (publication number: CN215051188U), a machine head rotating template machine on a sewing machine (publication number: CN221681367U) disclosed in Chinese patent literature also adopts the structure that the machine head and the bottom shuttle system follow the sewing direction to rotate, so as to avoid the appearance of reverse stitches in the sewing process. However, although the computer sewing machine of this type solves the technical problem of ensuring uniform stitches, it still has the following disadvantages:

[0007] 1. The machine head and the bottom shuttle system in the computer sewing machine rotate along with the fabric feeding direction, resulting in complex mechanism and high precision requirement. The complex mechanical structure is prone to cumulative error, which causes the machine head and the bottom shuttle system to deviate in rotation angle or rotation synchronization, thereby affecting the sewing precision and causing problems such as uneven stitches and needle skipping. Therefore, the existing computer sewing machine still has the problems of insufficient sewing quality and insufficient sewing aesthetics.

[0008] 2. The machine head and the bottom shuttle system follow the sewing direction to rotate, which requires the addition of corresponding driving structure and transmission structure, and the mechanical structure of the machine head and the bottom shuttle system is more complex, which leads to the increase of sewing machine parts and high manufacturing cost of the sewing machine.

[0009] At present, in order to solve the problem of insufficient sewing quality caused by the rotation of the machine head and the bottom shuttle system along with the sewing direction, the conventional technical means adopted by the technical personnel in the field is:

[0010] 1. In the manufacturing process, high-precision machining technology is adopted to manufacture key components, improve the assembly precision and running precision of the sewing mechanism, reduce error accumulation, and improve the sewing quality.

[0011] 2. By optimizing the control algorithm, the synchronization of the machine head and the rotating shuttle is improved, and the error is reduced.

[0012] 3. The use of synchronous belt or synchronous gear transmission ensures that the head and the bottom shuttle system can rotate synchronously when the sewing direction changes, reduces the deviation of the rotation angle, and improves the sewing quality. SUMMARY

[0013] The utility model discloses to the above-mentioned problem of prior art, propose a sewing machine, the utility model discloses can avoid the appearance of reverse stitch in the sewing process, solve the problem of insufficient sewing quality of the existing sewing machine simultaneously.

[0014] The utility model discloses a sewing machine, including base, the needle plate with the needle drop hole and the rotating shuttle below needle plate, its characterized in that, this sewing machine still includes the thread shifting lever and rotatable rotating part, be equipped with the guide on the base and can swing the rotating shuttle side part, the thread shifting lever includes the pole body and the thread shifting head of strip, the pole body is along its axial direction sliding connection on the guide, the thread shifting head one end fixed connection on the pole body near the rotating shuttle one end, the other end of pole body rotatory connection on the rotating part deviates its rotating center's position, when rotating part drives the pole body movement, the other end of thread shifting head can be between needle drop hole and rotating shuttle.

[0015] For sewing machine, the space between rotating shuttle and needle plate is very limited, thus, how to make the thread shifting lever can carry out the thread shifting action between rotating shuttle and needle plate is very critical. In the utility model, the thread shifting lever includes the pole body and the thread shifting head of strip, and the pole body structure is favorable to the installation and guidance of the thread shifting lever, guarantees the stability of the thread shifting lever during movement, and the thread shifting head is designed as a strip to ensure that it can smoothly move to the narrow space between the needle plate and the rotating shuttle to perform the thread shifting action.

[0016] When the sewing machine is used for sewing a pattern, the sewing material will move horizontally in different directions with the feeding device. When the sewing machine is used for forward sewing, the rotating part can not rotate, and the thread shifting lever does not perform the thread shifting action at this time. When the feeding direction of the sewing material is changed to make the sewing machine perform reverse sewing, if the position of the bottom thread between the rotating shuttle and the needle plate is not changed through the thread shifting lever, the needle will normally drop, and at this time, a reverse stitch will be formed. The reason is that after the rotating shuttle expands the thread loop and covers the bottom thread, the needle needs to move upward. During this process, the thread on the needle will pass between the bottom thread and the thread on the cloth and tighten upward, and finally the thread and the bottom thread are intertwined to form a "knot", that is, a reverse stitch.

[0017] In the sewing machine, a thread shifting rod is added to the side of the rotating hook, and the rod body is connected to a horizontally swingable guide member in axial sliding manner. The rod body is connected to a thread shifting head at one end close to the rotating hook, and is rotatably connected to the rotating member at the other end at a position deviated from the rotating center of the rotating member. When the rotating member rotates, the rod body moves axially and swings, and the thread shifting head at the end of the rod body performs a circumferential circular motion. The direction of the circular motion of the thread shifting head can be controlled by controlling the rotating direction of the rotating member. When the rotating member drives the rod body to move, the other end of the thread shifting head can be located between the drop hole and the rotating hook. That is, during the circular motion of the thread shifting head, the other end of the thread shifting head can pass through the gap between the drop hole and the rotating hook.

[0018] When the sewing machine sews in reverse, the rotating member starts to rotate, and drives the rod body to move before the needle goes down. When the other end of the thread shifting head passes through the gap between the drop hole and the rotating hook, the bottom thread between the rotating hook and the needle plate is pushed, and a part of the bottom thread crosses the axial line of the needle. Then, the needle goes down again. When the needle moves downward to bring the face thread below the needle plate, the other end of the thread shifting head does not simply swing back and forth, but performs a circumferential circular motion, and has a stroke of moving to the side of the rotating hook. Therefore, the other end of the thread shifting head can be separated from the bottom thread after the needle goes down. At this time, the bottom thread cannot be reset to the initial position due to the blockage of the needle, so that the face thread on the needle is on the same side as the bottom thread and the face thread on the cloth during the tightening process of the needle moving upward. Therefore, the face thread on the needle does not pass through the bottom thread and the face thread on the cloth to be tightened, so that the face thread and the bottom thread are not knotted, and a beautiful forward stitch is finally formed. In addition, the thread shifting head is separated from the bottom thread, so that the rotating hook expands the face thread loop, and the process of the rotating hook sleeving the bottom thread is not interfered by the thread shifting head.

[0019] Therefore, the sewing machine with the thread shifting rod having the stitch conversion function effectively avoids the generation of reverse stitches during sewing. Moreover, the design only needs to cooperate with the needle going down to control the thread shifting rod to move, and does not need the head and the rotating hook to rotate with the sewing direction, so as to eliminate the problem of reduced sewing quality caused by the deviation of the rotating angle or the synchronization deviation of the head and the rotating hook. Therefore, the design of the sewing machine not only reduces the control difficulty, but also significantly reduces the sewing error, and further improves the sewing quality.

[0020] In the above-mentioned sewing machine, the rotating member can horizontally rotate, the guide member can horizontally swing, the rod body is in straight rod shape and is horizontally arranged, and the thread shifting head is a metal strip bent to form.

[0021] The straight rod-shaped rod body is beneficial to the installation and guidance of the thread poking rod, ensures the stability of the movement process of the thread poking rod, and has high thread poking precision. The thread poking head is formed by bending a metal strip, which is convenient to manufacture, and has a small diameter, which can facilitate the extension into the narrow space between the needle plate and the rotating hook for thread poking action.

[0022] In the above sewing machine, when the rod body moves to make the other end of the thread poking head between the needle falling hole and the rotating hook, the thread poking head is close to the outer peripheral wall of the rotating hook. When the rod body moves to make the other end of the thread poking head between the needle falling hole and the rotating hook, the thread poking head is close to the outer peripheral wall of the rotating hook, which is beneficial to reducing the occupation of the space near the rotating hook by the thread poking head while realizing the thread poking function, thereby avoiding interference with components such as thread cutting components, and the layout is more reasonable.

[0023] In the above sewing machine, the base includes a seat body and a motor seat fixedly connected to the outer wall of the seat body, a motor with a vertical rotating shaft is fixedly arranged on the motor seat, the rotating member is a disc-shaped thread poking wheel, and the rotating member is connected to the rotating shaft of the motor and arranged concentrically. The motor is fixedly connected to the outer wall of the seat body through the motor seat, which is convenient for the installation and maintenance of the motor and avoids the occupation of the internal space of the seat body. The design of the thread poking wheel can stably drive the axial movement and swinging of the thread poking rod, and the thread poking wheel has the advantages of simple structure and small space occupation, thereby facilitating the installation of the thread poking rod in the limited space in the seat body.

[0024] In the above sewing machine, the base includes a seat body and a motor seat fixedly connected to the outer wall of the seat body, a motor with a vertical rotating shaft is fixedly arranged on the motor seat, the rotating member is a disc-shaped thread poking wheel, and the rotating member is connected to the rotating shaft of the motor and arranged concentrically. The motor is fixedly connected to the outer wall of the seat body through the motor seat, which is convenient for the installation and maintenance of the motor and avoids the occupation of the internal space of the seat body. The design of the thread poking wheel can stably drive the axial movement and swinging of the thread poking rod, and the thread poking wheel has the advantages of simple structure and small space occupation, thereby facilitating the installation of the thread poking rod in the limited space in the seat body.

[0025] In the above sewing machine, the base further includes a connecting plate, the outer wall of the seat body has a clearance, the connecting plate passes through the clearance, the outer end of the connecting plate is fixedly connected to the motor seat, the inner end of the connecting plate extends into the seat body and is close to the rotating hook, and the guide member is rotatably connected to the inner end of the connecting plate.

[0026] On the basis of the external motor, the guide member is rotatably connected to the inner end of the connecting plate by arranging the clearance on the seat body and the connecting plate extending into the internal space of the seat body, so that the guide member is close to the rotating hook, which is beneficial to providing stable support and guidance for the end of the rod body close to the rotating hook, preventing the rod body from deviating or shaking during the movement process, making the thread poking position of the thread poking head connected to the rod body accurate, and avoiding the failure of thread poking caused by action errors.

[0027] In the sewing machine, the front side of the other end of the thread shifting head is provided with an avoiding cut surface, the rotating part rotates to drive the rod body to move reciprocatingly along the axial direction and swing forward and backward, and the swing amplitude is smaller than the axial movement amplitude.

[0028] The front side of the other end of the thread shifting head is provided with an avoiding cut surface, so that the other end of the thread shifting head can effectively avoid the needle during movement, avoiding collision or interference with the needle. Moreover, the design of the avoiding cut surface makes the forward and backward swing amplitude of the thread shifting rod smaller, thereby shortening the swing stroke of the rod body, and the smaller swing stroke means faster movement speed and higher efficiency, thereby improving the sewing efficiency of the sewing machine. At the same time, the larger amplitude of the axial movement of the rod body can ensure that the thread shifting head smoothly separates from the bottom thread, ensure that the rotating hook can smoothly hook the face thread, and interweave with the bottom thread after expanding the face thread loop, thereby improving the working stability and reliability of the sewing machine.

[0029] In the sewing machine, the end face of the rod body near the rotating hook is provided with an insertion hole, one end of the thread shifting head is matched and inserted into the insertion hole, and a locking screw is screwed on the outer wall of the rod body and abuts against the thread shifting head. By tightening the locking screw, the thread shifting head can be firmly fixed in the insertion hole, preventing the thread shifting head from loosening or deviating during movement. At the same time, the design allows the position of the thread shifting head to be adjusted, ensuring that the position accuracy of the thread shifting head reaches the best state, thereby improving the accuracy of the thread shifting position of the thread shifting rod, avoiding the situation that the thread shifting is not in place or fails, and ensuring that the thread shifting head does not collide with the needle during movement, making the sewing process more stable and improving the sewing quality and the safety and reliability of the sewing machine.

[0030] In the sewing machine, the guide piece is provided with a guide hole, a guide sleeve coaxial with the guide hole is arranged in the guide hole, and the middle segment of the rod body is slidably arranged in the guide sleeve. This structure can improve the guiding effect of the guide piece, allowing the rod body to stably move along the axial direction. At the same time, the guide sleeve can also provide good support to the rod body, avoiding excessive deflection caused by deformation of the rod body, thereby ensuring stable thread shifting action and accurate thread shifting position of the thread shifting rod.

[0031] In the sewing machine, the rod body is integrally formed with a sliding block, the guide piece is provided with a sliding groove parallel to the rod body, and the sliding block is slidably connected in the sliding groove. This structure can not only guide the rod body but also provide good support to the rod body, avoiding excessive deflection caused by deformation of the rod body, thereby ensuring stable thread shifting action and accurate thread shifting position of the thread shifting rod.

[0032] In the sewing machine, the thread shifting rod further comprises a connecting head, and the other end of the rod body is rotatably connected to the rotating member through the connecting head. The connecting head is manufactured separately from the rod body, which is convenient for manufacturing and facilitates the rotatable connection of the rod body and the rotating member through the connecting head.

[0033] In the sewing machine, the thread shifting head is in the shape of an arc and is upwardly bent relative to the rod body. This design can make the thread shifting head closer to the outer peripheral wall of the rotating hook during the thread shifting operation, so as to reduce the space occupied by the thread shifting head around the rotating hook while realizing the thread shifting function. In addition, the upward bending of the thread shifting head relative to the rod body can also lower the installation position of the rod body, thereby lowering the installation position of the guide member for guiding the rod body, and avoiding the situation that the guide member cannot be installed or is difficult to be installed due to being too close to the sewing table surface of the base.

[0034] Compared with the prior art, the sewing machine has the following advantages:

[0035] 1. In the sewing machine, the thread shifting rod is added, which has the function of "stitch conversion", can avoid the appearance of reverse stitches during sewing, ensure the beauty and consistency of sewing, and enable the computerized sewing machine to be well applied to the sewing of some high-end garments, leather products and other occasions with high requirements on sewing quality.

[0036] 2. In the sewing machine, only the needle lowering action of the needle is required to control the reciprocating movement of the thread shifting rod above the rotating hook, and the head and the rotating hook do not need to rotate with the sewing direction, thereby eliminating the problem of reduced sewing quality caused by the deviation of the rotation angle or the deviation of the synchronization of the head and the rotating hook. Therefore, the design of the computerized sewing machine not only reduces the control difficulty, but also significantly reduces the sewing error and further improves the sewing quality.

[0037] 3. In the computerized sewing machine, the head and the rotating hook only need to maintain a constant direction for sewing, thereby simplifying the structure of the sewing machine and significantly reducing the manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a top view of the rotating hook and the thread shifting rod.

[0039] Figure 2 is a schematic view of a partial structure of the sewing machine.

[0040] Figure 3 is an enlarged view of the rotating hook part of the sewing machine.

[0041] Figure 4 is a schematic view of a partial structure of the sewing machine.

[0042] Figure 5 is a partial sectional view of the thread shifting rod and the guide member.

[0043] Figure 6 is a schematic diagram of a forward stitch (301 stitch).

[0044] Figure 7 is a schematic diagram of a reverse stitch (319 stitch).

[0045] Figure 8 is a schematic diagram of a sewing process Figure 1 .

[0046] Figure 9 is a schematic diagram of the principle of forming a reverse stitch.

[0047] Figure 10 is a schematic diagram of a sewing process Figure 2 .

[0048] Figure 11 is a schematic diagram of the movement of the bottom thread driven by the thread lever.

[0049] Figure 12 is a schematic diagram of the stitch area of Example Two.

[0050] Figure 13 is a schematic diagram of the mounting structure of the thread lever in Example Three.

[0051] In the figure, 1, base; 1a, seat body; 1a1, clearance; 1b, connecting plate; 1c, motor seat; 2, needle plate; 21, needle drop hole; 3, rotating shuttle; 31, thread outlet; 32, shuttle tip; 4, thread lever; 41, lever body; 411, plug-in hole; 412, sliding block; 42, thread lever head; 421, avoidance cutting surface; 43, connecting head; 5, motor; 6, rotating piece; 7, guide piece; 71, guide hole; 72, sliding groove; 8, guide sleeve; 9, locking screw; 10, machine needle. DETAILED DESCRIPTION

[0052] The following are specific embodiments of the present application and further describe the technical solutions of the present application in combination with the accompanying drawings, but the present application is not limited to these embodiments.

[0053] Example One

[0054] As Figure 1 and Figure 2As shown, the sewing machine comprises a base 1, a thread shifting lever 4, a needle plate 2 with a needle drop hole 21, a rotating hook 3 below the needle plate 2, a rotating member 6 capable of horizontal rotation, and a feeding device on the top surface of the base 1 for fixing and moving the sewing material. The feeding device is a prior art and not shown in the figure. The feeding device is usually a feeding template. The base 1 further comprises a guide member 7 capable of horizontal swinging on the side of the rotating hook 3. The base 1 comprises a seat body 1a, a connecting plate 1b, and a motor seat 1c fixedly connected to the outer wall of the seat body 1a. A motor 5 is fixedly arranged on the motor seat 1c. The outer wall of the seat body 1a has a clearance 1a1. The connecting plate 1b passes through the clearance 1a1. The outer end of the connecting plate 1b is fixedly connected to the motor seat 1c. The inner end of the connecting plate 1b extends into the inner side of the seat body 1a and is close to the rotating hook 3. The guide member 7 is rotationally connected to the inner end of the connecting plate 1b. The rotating member 6 is a disc-shaped thread shifting wheel. The rotating member 6 is connected to the rotating shaft of the motor 5 and is concentrically arranged.

[0055] As shown in the figure, Figures 3 to 5 The thread shifting lever 4 comprises a straight rod-shaped lever body 41, a connecting head 43, and an arc-shaped thread shifting head 42. The lever body 41 is axially and slidingly connected to the guide member 7. One end of the thread shifting head 42 is fixedly connected to one end of the lever body 41 close to the rotating hook 3 and is upwardly bent relative to the lever body 41. The other end of the lever body 41 is rotationally connected to the rotating member 6 at a position deviated from the rotating center of the rotating member 6 through the connecting head 43. When the rotating member 6 moves the lever body 41, the other end of the thread shifting head 42 can be between the needle drop hole 21 and the rotating hook 3. Specifically, when the rotating member 6 rotates, it can drive the lever body 41 to reciprocatingly move axially and swing at the same time, so that the thread shifting head 42 at the end of the lever body 41 performs a circumferential circular motion. During the motion, the other end of the thread shifting head 42 can pass through the gap between the needle drop hole 21 and the rotating hook 3. The swinging amplitude of the lever body 41 is smaller than the axial movement amplitude. The motor 5 is preferably a servo motor. Through the rotating direction of the motor 5, the direction of the circumferential circular motion of the thread shifting head 42 can be controlled.

[0056] Further, as shown in the figures, Figure 2 and Figure 4 The thread shifting head 42 is formed by bending a metal strip. The diameter of the thread shifting head 42 is smaller than the diameter of the lever body 41. When the lever body 41 moves to make the other end of the thread shifting head 42 between the needle drop hole 21 and the rotating hook 3, the thread shifting head 42 is close to the outer peripheral wall of the rotating hook 3. Such design is beneficial to realize the thread shifting function while reducing the occupation of the space near the rotating hook 3 by the thread shifting head 42, thereby avoiding interference with components such as thread cutting components, and the layout is more reasonable. Further, the front side of the other end of the thread shifting head 42 has an avoiding cutting surface 421. The design of the avoiding cutting surface 421 enables the other end of the thread shifting head 42 to effectively avoid the needle 10 during the motion, thereby avoiding collision or interference with the needle 10.

[0057] As Figure 5 As shown, the guide 7 has a guide hole 71, and a guide sleeve 8 coaxial with the guide hole 71 is arranged in the guide hole 71, and the middle section of the rod body 41 is slidably arranged in the guide sleeve 8. An insertion hole 411 is formed in the end surface of the rod body 41 close to the hook 3, and one end of the wire pushing head 42 is inserted into the insertion hole 411, and a locking screw 9 is screwed on the outer wall of the rod body 41, and the inner end of the locking screw 9 abuts against the wire pushing head 42. This design allows the position of the wire pushing head 42 to be finely adjusted, ensuring that the position accuracy of the wire pushing head 42 is optimal, thereby improving the accuracy of the wire pushing position of the wire pushing rod 4 and avoiding the situation that the wire is not pushed to the correct position or the wire pushing fails.

[0058] The working principle of the sewing machine is briefly described as follows:

[0059] In this embodiment, the axis of the hook 3 is horizontally arranged along the front-rear direction of the sewing machine, the hook 3 has a hook tip 32 and a thread outlet 31 through which the bobbin thread is threaded, and the hook tip 32 moves to the rear side of the needle 10 to hook the thread on the needle 10. The plane in which the axis of the hook 3 and the needle 10 are located is the critical plane A, and the line connecting the thread outlet 31 and the needle drop hole 21 is obliquely arranged, and the vertical plane in which the line is located is the critical plane B. When the hook tip 32 of the bobbin moves to the needle 10, the area between the side of the critical plane A facing away from the thread outlet 31 and the side of the critical plane B facing away from the hook tip 32 is the reverse stitch area a, and the remaining area is the forward stitch area b. For a certain sewing machine or the same type of sewing machine, since the structure (including the type, installation position, hooking direction of the hook 3, and the position of the thread outlet 31) and the position of the needle 10 are determined, the critical plane A and the critical plane B are determined, and the reverse stitch area a and the forward stitch area b are also determined.

[0060] In the actual sewing process of the sewing machine, the following steps can be performed:

[0061] 1. The control system generates the needle point trajectory and the movement trajectory of the feeding device according to the sewing pattern, and determines whether the feeding device moves to the reverse stitch area a after each needle is sewn, if so, the needle point corresponding to the next needle is determined as a reverse stitch needle point and recorded;

[0062] 2. The sewing machine starts working and sews the first needle;

[0063] 3. The feeding device moves the sewing material to the next needle sewing position according to the movement trajectory, and performs the following actions according to whether the needle point at the current sewing position is a reverse stitch needle point recorded in the control system:

[0064] If yes, the control system controls the wire shifting rod 4 to move, so that the other end of the wire shifting head 42 moves from the front lower side of the drop point hole 21 to the rear lower side, and pushes the bottom thread between the rotating hook 3 and the needle plate 2 in the process of movement, so that the bottom thread part crosses the axis of the needle 10. Then, the motor 5 continues to drive the wire shifting rod 4 to move, so that the other end of the wire shifting head 42 moves from the rear lower side of the drop point hole 21 to the left and away from the rotating hook 3, so that the other end of the wire shifting head 42 is separated from the bottom thread. Then, the needle 10 continues to move downward to the lowest point, and then moves upward to form a thread loop on the face thread on the needle 10. In the process of upward movement of the needle 10, the hook point 32 of the rotating hook 3 hooks the face thread on the needle 10 from the rear side of the needle 10, and expands the thread loop, so that the thread loop is sleeved on the bottom thread to interweave with the bottom thread. When the needle 10 continues to move upward to the highest point, the face thread and the bottom thread are tightened to form a stitch, and at the same time, the motor 5 continues to drive the wire shifting rod 4 to move, so that the other end of the wire shifting head 42 is returned to the front lower side of the drop point hole 21.

[0065] If no, the wire shifting rod 4 can be in a static waiting state, and the sewing machine can normally sew.

[0066] 4. Repeat step 3 and perform subsequent sewing according to the stitch trajectory obtained according to the sewing pattern.

[0067] Further, in step 3, when the stitch point at the current sewing position is not the reverse stitch stitch point recorded in the control system, the wire shifting rod 4 can also continue to perform the wire shifting action. At this time, in the process of moving the other end of the wire shifting head 42 from the front lower side of the drop point hole 21 to the rear lower side, even if the bottom thread is pushed, the bottom thread will not cross the axis of the needle 10. Therefore, in this case, the wire shifting rod 4 performs the above wire shifting action or is in a static waiting state, which is essentially the same, and both can form a forward stitch.

[0068] In the working process of the sewing machine, when step 3 is performed, the stitch point at the current sewing position is not the reverse stitch stitch point recorded in the control system, and the feeding device moves to the forward stitch area b for feeding, and the sewing machine is in a forward sewing state. At this time, the needle 10 moves upward with the face thread, and in the process of tightening the face thread, as shown in FIG. 6, the bottom thread between the rotating hook 3 and the needle plate 2 and the face thread on the cloth are all located on the same side of the face thread on the needle 10. Therefore, the wire shifting rod 4 does not need to change the position of the bottom thread between the rotating hook 3 and the needle plate 2, and can form a forward stitch (i.e., a 301 stitch) as shown in FIG. 7. Figure 8 Figure 6

[0069] ​​When the needle point of the current sewing position is the reverse trace needle point recorded in the control system, the feeding device moves to the reverse trace area a for feeding, and the sewing machine is in the reverse sewing state. At this time, if the position of the bobbin thread between the rotating hook 3 and the needle plate 2 is not changed by the thread shifting lever 4, the needle 10 directly normally lowers, at this time, the reverse trace is formed, and the reason is that, as shown in Figure 9 , after the rotating hook 3 expands the thread loop and the bobbin thread is sleeved on the bobbin thread, the needle 10 needs to move upward. In this process, the bobbin thread on the needle 10 will pass through the bobbin thread and the thread on the fabric and be tightened upward, and finally the bobbin thread and the thread are intertwined to form a “knot”, that is, the reverse trace (i.e., 319 trace) as shown in Figure 7 .

[0070] In the sewing machine, since the step of changing the position of the bobbin thread by the thread shifting lever 4 is added in step 3, before the needle 10 lowers, the bobbin thread between the rotating hook 3 and the needle plate 2 is moved and acted on by the thread shifting lever 4, so that a part of the bobbin thread crosses the axis of the needle 10, and then the needle 10 lowers, as shown in Figure 11 , the front and rear states of the bobbin thread moved by the thread shifting lever 4 can be clearly understood, Figure 11 , the thick solid line T represents the position state of the bobbin thread between the rotating hook 3 and the needle plate 2 when the thread shifting lever 4 does not perform the thread shifting action, and the thin solid line t represents the position state of the bobbin thread between the rotating hook 3 and the needle plate 2 after the thread shifting lever 4 performs the thread shifting action. As can be seen from the thin solid line t, a part of the bobbin thread crosses the axis of the needle 10. When the needle 10 moves downward to bring the thread to the lower side of the needle plate 2, the thread shifting head 42 of the thread shifting lever 4 is separated from the bobbin thread, at this time, the bobbin thread cannot be reset to the initial position due to the blockage of the needle 10, so that the thread on the needle 10 is no longer passed through between the bobbin thread and the thread on the fabric to be tightened, thereby avoiding the “knot” of the thread and the bobbin thread, and finally forming the forward trace as shown in Figure 10 . Figure 9 Figure 6 .

[0071] Embodiment Two

[0072] The structure and principle of this embodiment are basically the same as those of embodiment one, and the difference lies in that the type of the rotating hook 3 is different, and specifically, as shown in Figure 12 ​, the axis line of the rotating hook 3 is horizontally arranged along the front-rear direction of the sewing machine, the rotating hook 3 has a hook tip 32 and a thread outlet 31 for the bobbin thread to pass through, and the hook tip 32 moves to the front side of the needle 10 to hook the thread on the needle 10. The plane where the axis line of the rotating hook 3 and the needle 10 are located is the critical plane A, the line connecting the thread outlet 31 and the drop needle hole 21 is arranged obliquely, and the vertical plane where the line is located is the critical plane B. When the hook tip 32 of the bobbin moves to the needle 10, the area between the side of the critical plane A facing away from the thread outlet 31 and the side of the critical plane B facing away from the hook tip 32 is the reverse stitch area a, and the remaining area is the forward stitch area b.

[0073] In the actual sewing process of the sewing machine, the following steps can be performed:

[0074] 1. The control system generates the needle point trajectory and the movement trajectory of the feeding device according to the sewing pattern, and determines whether the feeding device moves to the reverse stitch area a after each needle is sewn. If yes, the needle point corresponding to the next needle is determined as a reverse stitch needle point and recorded.

[0075] 2. The sewing machine starts working and sews the first needle.

[0076] 3. The feeding device moves the sewing material to the next needle sewing position according to the movement trajectory. According to whether the needle point at the current sewing position is a reverse stitch needle point recorded in the control system, the following actions are performed:

[0077] If yes, the control system controls the thread shifting lever 4 to move, so that the other end of the thread shifting head 42 moves from the lower rear side of the drop needle hole 21 to the lower front side, and in the process of moving, pushes the bobbin thread between the rotating hook 3 and the needle plate 2, so that the bobbin thread part crosses the axis line where the needle 10 is located. Then, the motor 5 continues to drive the thread shifting lever 4 to move, so that the other end of the thread shifting head 42 moves from the lower front side of the drop needle hole 21 to the side and away from the rotating hook 3, so that the other end of the thread shifting head 42 is separated from the bobbin thread. Then, the needle 10 continues to move downward to the lowest point, and then moves upward to form a thread loop on the needle 10. In the process of upward movement of the needle 10, the hook tip 32 of the rotating hook 3 hooks the thread on the needle 10 from the front side of the needle 10, and expands the thread loop, so that the thread loop is sleeved on the bobbin thread to interweave with the bobbin thread. When the needle 10 continues to move upward to the highest point, the thread and the bobbin thread are tightened to form a stitch, and at the same time, the motor 5 continues to drive the thread shifting lever 4 to move, so that the other end of the thread shifting head 42 is returned to the lower front side of the drop needle hole 21.

[0078] If no, the thread shifting lever 4 can be in a static waiting state, the sewing machine normally sews, and the shape is a forward stitch.

[0079] 4. Repeat step 3 and perform subsequent sewing according to the needle point trajectory obtained by the sewing pattern.

[0080] The principle of "line trace conversion" implemented in this embodiment is similar to that in Embodiment 1, and will not be described in detail here.

[0081] Example 3

[0082] This embodiment is basically the same as embodiment one in structure and principle, except that: Figure 13 As shown, a motor 5 with a vertically oriented rotating shaft is fixed on the motor base 1c. A strip-shaped rotating component 6 is attached, with one end fixedly connected to the rotating shaft of the motor 5 and the other end rotatably connected to the other end of the rod 41. The strip-shaped rotating component 6 is easy to manufacture, low in cost, and can stably drive the rod 41 to reciprocate and swing axially. A slider 412 is integrally formed on the rod 41, and a groove 72 parallel to the rod 41 is provided on the guide component 7. The slider 412 is slidably connected within the groove 72.

[0083] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0084] Although this document frequently uses terms such as 1. base; 1a. seat body; 1a1. clearance opening; 1b. connecting plate; 1c. motor base; 2. needle plate; 21. needle drop hole; 3. rotary hook; 31. thread outlet; 32. hook tip; 4. thread guide lever; 41. lever body; 411. insertion hole; 42. thread guide head; 421. clearance cut surface; 43. connector; 5. motor; 6. rotating component; 7. guide component; 71. guide hole; 8. guide sleeve; 9. locking screw; 10. needle, etc., the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A sewing machine comprising a base (1), a needle plate (2) having a needle drop hole (21), and a rotary hook (3) located below the needle plate (2), characterized in that, This sewing machine also includes a thread guide (4) and a rotatable rotating component (6). The base (1) is provided with a guide (7) located on the side of the rotary hook (3) and capable of swinging. The thread guide (4) includes a rod body (41) and a strip-shaped thread guide head (42). The rod body (41) is slidably connected to the guide (7) along its axial direction. One end of the thread guide head (42) is fixedly connected to the end of the rod body (41) near the rotary hook (3). The other end of the rod body (41) is rotatably connected to the rotating component (6) at a position off its rotation center. When the rotating component (6) drives the rod body (41) to move, the other end of the thread guide head (42) can be positioned between the needle drop hole (21) and the rotary hook (3).

2. The sewing machine according to claim 1, characterized in that, The rotating component (6) can rotate horizontally, the guide component (7) can swing horizontally, the rod body (41) is straight and horizontally arranged, and the wire pull head (42) is formed by bending a metal strip.

3. The sewing machine according to claim 1, characterized in that, When the rod (41) moves to the point where the other end of the thread-pulling head (42) is between the needle hole (21) and the rotary hook (3), the thread-pulling head (42) comes into close contact with the outer peripheral wall of the rotary hook (3).

4. The sewing machine according to claim 1, 2, or 3, characterized in that, The base (1) includes a seat body (1a) and a motor seat (1c) fixedly connected to the outer wall of the seat body (1a). A motor (5) with a vertically arranged rotating shaft is fixed on the motor seat (1c). The rotating component (6) is a disc-shaped dial wheel. The rotating component (6) is connected to the rotating shaft of the motor (5) and is arranged concentrically.

5. The sewing machine according to claim 1, 2, or 3, characterized in that, The base (1) includes a seat (1a) and a motor seat (1c) fixedly connected to the outer wall of the seat (1a). A motor (5) with a vertically arranged rotating shaft is fixedly mounted on the motor seat (1c). The rotating component (6) is strip-shaped. One end of the rotating component (6) is fixedly connected to the rotating shaft of the motor (5), and the other end is rotatably connected to the other end of the rod (41).

6. The sewing machine according to claim 4, characterized in that, The base (1) also includes a connecting plate (1b). The outer wall of the seat body (1a) has a clearance opening (1a1). The connecting plate (1b) passes through the clearance opening (1a1). The outer end of the connecting plate (1b) is fixedly connected to the motor seat (1c). The inner end extends into the inner side of the seat body (1a) and is close to the rotary hook (3). The guide (7) is rotatably connected to the inner end of the connecting plate (1b).

7. The sewing machine according to claim 3, characterized in that, The other end of the dial head (42) has a clearance cut surface (421) on its front side. When the rotating part (6) rotates, it can drive the rod body (41) to move back and forth along the axial direction and swing back and forth at the same time, and the swing amplitude is less than the amplitude of the axial movement.

8. The sewing machine according to claim 1, 2, or 3, characterized in that, The rod (41) has a plug hole (411) on the end face near the rotary hook (3). One end of the wire puller (42) is plugged into the plug hole (411). A locking screw (9) is screwed onto the outer wall of the rod (41). The inner end of the locking screw (9) abuts against the wire puller (42).

9. The sewing machine according to claim 1, 2, or 3, characterized in that, The dial head (42) is arc-shaped and bends upward relative to the rod (41).

10. The sewing machine according to claim 1, 2, or 3, characterized in that, A slider (412) is integrally formed on the rod (41), and a groove (72) parallel to the rod (41) is provided on the guide (7), and the slider (412) is slidably connected in the groove (72).

Images