Flexible auxiliary thread feeding device and intelligent sewing machine

Abstract

The utility model relates to sewing machine technical field especially a kind of flexible auxiliary thread supply device and intelligent sewing machine.Flexible auxiliary thread supply device includes driving motor, thread take-up cam and thread guide, driving motor is set in the shell of sewing machine, driving motor is independently driven the rotation of thread take-up cam around axis by transmission mechanism outside the shell, thread guide is set outside the shell and is located below thread take-up cam, the middle position of thread guide is equipped with the avoidance slot for the rotation of thread take-up cam to pass, thread guide is equipped with inside thread guide hook in the side close to shell, and outside thread guide hook is equipped with in the side away from shell, inside thread guide hook and outside thread guide hook are all position-adjustably installed on thread guide;And intelligent sewing machine uses the flexible auxiliary thread supply device of this utility model.The flexible auxiliary thread supply device and intelligent sewing machine of the utility model are convenient to adjust, and adjustment effect is good.

Description

Technical Field

[0001] This utility model relates to the field of sewing machine technology, and in particular to a flexible auxiliary thread supply device, and an intelligent sewing machine using the flexible auxiliary thread supply device. Background Technology

[0002] See Figure 1 and Figure 2 In existing lock sewing machines, the thread take-up mechanism is usually a four-bar linkage consisting of a thread take-up crank 1, a connecting rod 2, a rocker arm, and a thread take-up lever 3. The entire thread take-up mechanism is set inside the machine housing 4 of the lock sewing machine. A long slot is opened on the side of the machine housing 4. The thread hole E on the thread take-up lever 3 extends out of the machine housing 4 through the long slot. The thread take-up crank 1 rotates at a constant speed with the main shaft and transmits power to the thread take-up lever 3 through the connecting rod 2 and the rocker arm, thereby driving the thread take-up lever 3 to move up and down along the long slot.

[0003] When performing the string-picking action, see Figure 3 The thread passes sequentially through the right hook N, the thread guide hole E, and the left hook M. As the thread take-up lever 3 moves up and down, the spatial position of the thread guide hole E changes continuously, thus causing a change in the amount of thread supplied. After the spatial position of the thread guide hole E changes, the lengths of thread segments EN and EM will change. Let L be the lengths of these two thread segments respectively. EN and L EM Let R be the total length of the two line segments. （φ） Then R （φ） =L EN +L EM Where φ is the principal axis rotation angle, and R is the rotation angle. （φ） It varies with the value of φ. Within one working cycle, when the wire hole E is at its highest point, R... （φ） It has a maximum value R （φ）max Maximum value R （φ）max Subtract the sum R of the line segments at a certain moment （φ） The excess thread can be used to form thread loops, which rotate around the rotary hook to form thread stitches. Therefore, this difference is the amount of thread supplied, denoted as ΔR. （φ） ΔR （φ） =R （φ）max -R （φ） .

[0004] The supply and demand relationship of existing lockstitch sewing machines is as follows: Figure 4 As shown, curve I represents the thread requirement for sewing thin fabrics with a small stitch pitch, curve II represents the thread requirement for sewing thick fabrics with a large stitch pitch, curve III represents the standard thread supply, and curve IV represents the thread supply after shifting the right hook to the left. Figure 4It can be seen that curve III can form an envelope of curve I, and the supply and demand of thread are reasonably matched; however, curves II and III have obvious interference in areas a, b, and c, resulting in insufficient thread supply, which can easily lead to poor stitches or even thread breakage. At this time, it is necessary to move the right hook to the left to adjust the overall thread supply to obtain curve IV. However, although the supply and demand of thread is significantly improved in area b, the leftward movement of the right hook has little impact on areas a and c. This is because the "quasi-sine" shape of the supply and demand of thread curve is determined by the structure and length parameters of the four-bar linkage take-up mechanism. Changing the position of the right hook alone can only play a minor role in adjusting the peak value of the thread supply, which is difficult to match diverse sewing scenarios.

[0005] To adapt to different sewing scenarios, the overall thread supply needs to be adjusted by rotating the connecting pin. However, this adjustment method not only requires removing the end cover of the machine housing for manual adjustment, which involves many steps and takes a long time, but also requires adding new positioning planes to the connecting pin. Due to the limitations of the structural strength and rigidity of the connecting pin, the number of positioning planes that can be machined on the connecting pin is extremely limited. Therefore, this adjustment method has a very limited impact on the amplitude and shape of the thread supply curve. Utility Model Content

[0006] In view of the above-mentioned defects of the prior art, the present invention provides a flexible auxiliary thread supply device and an intelligent sewing machine that are easy to adjust and have good adjustment effect.

[0007] The technical solution adopted by this utility model to solve its technical problem is:

[0008] This utility model provides a flexible auxiliary thread feeding device, including a drive motor, a thread take-up cam, and a thread guide frame. The drive motor is installed inside the sewing machine housing and independently drives the thread take-up cam outside the housing to rotate around its axis through a transmission mechanism. The thread guide frame is installed outside the housing and below the thread take-up cam. A clearance groove is provided in the middle of the thread guide frame for the thread take-up cam to pass through when rotating. The thread guide frame has an inner thread hook on the side closer to the housing and an outer thread hook on the side farther from the housing. Both the inner and outer thread hooks are adjustablely mounted on the thread guide frame.

[0009] Preferably, the drive shaft of the drive motor is arranged in the same direction as the main shaft of the sewing machine.

[0010] Preferably, the transmission mechanism includes a transmission shaft and a thread-taking camshaft. One end of the transmission shaft is connected to the drive shaft of the drive motor via a synchronous belt transmission sub-mechanism, and the other end of the transmission shaft is connected to the thread-taking camshaft via a bevel gear transmission sub-mechanism. The thread-taking camshaft and the thread-taking camshaft are interference-fitted.

[0011] Preferably, the wire guide frame is provided with sliding rails and threaded holes on both the side near the housing and the side away from the housing. The inner wire hook and the outer wire hook are provided with U-shaped locking ends and strip-shaped positioning grooves. The U-shaped locking ends can be slidably locked on the sliding rails, and the threaded fasteners are connected to the threaded holes after passing through the strip-shaped positioning grooves.

[0012] Preferably, the sliding track extends in a straight line from the head end of the housing to the base end.

[0013] Preferably, multiple thread-picking cams are spaced apart, and the drive motor drives all the thread-picking cams to rotate synchronously around the same axis. Multiple thread-passing plates are spaced apart above the clearance groove on the thread-passing frame. The center of the thread-passing plate is hollowed out to form a thread-passing hole. When all the thread-picking cams rotate through the clearance groove, there is a thread-passing plate between any two adjacent thread-picking cams.

[0014] Preferably, when all the wire-taking cams rotate through the clearance groove, a gap space is formed between any two adjacent wire-taking cams, and the wire-passing plate between any two adjacent wire-taking cams divides the gap space equally.

[0015] This utility model also provides an intelligent sewing machine, including a machine housing, a main drive motor, a processor, a thread take-up mechanism, and a flexible auxiliary thread supply device of any of the above. The machine housing is provided with a distance sensor, a left thread hook, and a right thread hook at the head end. The thread take-up mechanism has a thread hole at the end of the thread take-up lever that extends out of the machine housing. The main drive motor drives the thread take-up lever to move up and down reciprocally through the main shaft. The thread take-up cam and the thread guide are both arranged on the side of the thread take-up lever facing the machine housing. The processor is simultaneously connected to the distance sensor, the main drive motor, and the drive motor.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] When the flexible auxiliary thread feeding device of this utility model is installed on a sewing machine, it is equivalent to adding an auxiliary thread feeding mechanism that can take up the thread twice, in addition to the original thread take-up mechanism of the sewing machine. The top thread first passes through the inner thread hook, and then passes through the outer thread hook above the clearance groove of the thread guide frame. Then, the drive motor can easily and conveniently drive the thread take-up cam into the clearance groove to realize the flexible adjustment of the secondary thread feeding. It can also significantly adjust the shape of the thread feeding curve of the sewing machine, and the adjustment effect is good.

[0018] The intelligent sewing machine of this invention can detect and sense changes in fabric thickness through a distance sensor. In conjunction with the independent drive source of the flexible auxiliary thread supply device, it flexibly controls the secondary thread take-up process, changes the specific shape of the sewing machine's thread supply curve, and achieves the effect of adaptive sewing of materials of different thicknesses. This can reduce thread tension and improve the stability, flatness, and aesthetics of the fabric stitches. Attached Figure Description

[0019] Figure 1 This is a structural diagram of the head section of a lock sewing machine in the existing technology.

[0020] Figure 2 This is a schematic diagram of the thread take-up mechanism in a lock sewing machine in the prior art.

[0021] Figure 3 This is a schematic diagram illustrating the calculation of thread supply for the thread take-up mechanism in a lock sewing machine in the prior art.

[0022] Figure 4 This is a diagram showing the supply and demand relationship of thread in lockstrap sewing machines in the existing technology.

[0023] Figure 5 This is a structural diagram of the head section of the intelligent sewing machine in an embodiment of this utility model.

[0024] Figure 6 This is a diagram showing the connection structure of the wire-picking cam in the flexible auxiliary wire supply device according to an embodiment of this utility model.

[0025] Figure 7 This is a connection structure diagram of the wire feeder on the flexible auxiliary wire supply device in an embodiment of this utility model.

[0026] Figure 8 This is a structural diagram of the flexible auxiliary wire feeding device with the wire-picking cam in its conventional position, according to an embodiment of this utility model.

[0027] Figure 9 This is a front view of the flexible auxiliary wire feeding device in the wire-picking position in an embodiment of this utility model.

[0028] Figure 10 This is a side view of the flexible auxiliary wire feeding device in the wire-picking position in an embodiment of this utility model.

[0029] Figure 11 This is a schematic diagram illustrating the calculation of the thread supply amount of the flexible auxiliary thread supply device on the intelligent sewing machine in an embodiment of this utility model.

[0030] Figure 12 This is the first type of supply and demand thread relationship diagram that can be realized by the intelligent sewing machine in this embodiment of the utility model.

[0031] Figure 13 This is a second type of supply and demand thread relationship diagram that can be realized by the intelligent sewing machine in this embodiment of the utility model.

[0032] The reference numerals in the attached figures are explained as follows:

[0033] 1. Thread take-up crank; 2. Connecting rod; 3. Thread take-up lever; 4. Housing; 5. Drive motor; 6. Thread take-up cam; 7. Thread guide frame; 701. Clearance groove; 702. Sliding track; 703. Threaded hole; 8. Inner thread guide hook; 9. Outer thread guide hook; 10. Drive shaft; 11. Thread take-up camshaft; 12. Drive pulley; 13. Driven pulley; 14. Synchronous belt; 15. Driven bevel gear; 16. Driven bevel gear; 17. Thread take-up camshaft sleeve; 18. Thread guide plate; 1801. Thread hole; 19. Distance sensor; E. Thread hole; F. U-shaped snap-fit ​​end; G. Strip positioning groove; H. Interval space; M. Left thread hook; N. Right thread hook; P. Flexible auxiliary thread supply device. Detailed Implementation

[0034] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate this utility model and are not intended to limit it.

[0035] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0037] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0038] See Figures 5 to 7This embodiment provides a flexible auxiliary thread feeding device, including a drive motor 5, a thread take-up cam 6, and a thread guide frame 7. The drive motor 5 is installed inside the housing 4 of the sewing machine. The drive motor 5 independently drives the thread take-up cam 6 outside the housing 4 to rotate around an axis through a transmission mechanism. The thread guide frame 7 is installed outside the housing 4 and below the thread take-up cam 6. A clearance groove 701 is provided in the middle of the thread guide frame 7 for the thread take-up cam 6 to pass through when rotating. The thread guide frame 7 has an inner thread hook 8 on the side closer to the housing 4 and an outer thread hook 9 on the side farther from the housing 4. Both the inner thread hook 8 and the outer thread hook 9 are mounted on the thread guide frame 7 in an adjustable position.

[0039] When the flexible auxiliary thread feeding device of this embodiment is installed on a sewing machine, it is equivalent to adding an auxiliary thread feeding mechanism that can take up the thread twice, in addition to the original thread take-up mechanism of the sewing machine. The top thread first passes through the inner thread hook 8, and then passes through the outer thread hook 9 above the clearance groove 701 of the thread guide frame 7. Then, the drive motor 5 can easily and conveniently drive the thread take-up cam 6 into the clearance groove 701 to realize the flexible adjustment of the secondary thread feeding. It can also significantly adjust the shape of the thread feeding curve of the sewing machine, and the adjustment effect is good.

[0040] It should be noted that initially, the inner wire hook 8 and the outer wire hook 9 should be adjusted to the appropriate positions of the wire guide frame 7, and then the top wire should be passed through the inner wire hook 8 and the outer wire hook 9 in sequence.

[0041] The working principle of the flexible auxiliary wire feeding device in this embodiment is as follows: See [link / description] Figures 8 to 10 When the thread-taking cam 6 rotates clockwise from its normal position to the thread-taking position, the protruding part of the outer contour of the thread-taking cam 6 will push the surface thread above the clearance groove 701 of the thread guide 7 downward.

[0042] Preferably, the drive shaft of the drive motor 5 is arranged in the same direction as the main shaft of the sewing machine to make the sewing machine structure more compact.

[0043] Preferably, see Figure 6 The transmission mechanism includes a transmission shaft 10 and a thread-taking cam shaft 11. One end of the transmission shaft 10 is connected to the drive shaft of the drive motor 5 via a synchronous belt transmission sub-mechanism, and the other end of the transmission shaft 10 is connected to the thread-taking cam shaft 11 via a bevel gear transmission sub-mechanism. The thread-taking cam 6 is interference-fitted with the thread-taking cam shaft 11.

[0044] Better, see Figure 6In this embodiment, the synchronous belt drive sub-mechanism includes a driving pulley 12, a driven pulley 13, and a synchronous belt 14. The drive shaft of the drive motor 5 is axially connected to the driving pulley 12, and one end of the transmission shaft 10 is axially connected to the driven pulley 13. The synchronous belt 14 simultaneously engages with both the driving pulley 12 and the driven pulley 13 and drives the driven pulley 13 to rotate synchronously with the driving pulley 12.

[0045] Better, see Figure 6 In this embodiment, the bevel gear transmission submechanism includes a driving bevel gear 15 and a driven bevel gear 16. One end of the transmission shaft 10 is axially connected to the driving bevel gear 15, and the wire-picking cam shaft 11 is axially connected to the driven bevel gear 16. The driving bevel gear 15 and the driven bevel gear 16 mesh and transmit power.

[0046] Better, see Figure 6 In this embodiment, a thread-taking camshaft sleeve 17 is installed on the thread-taking camshaft 11, and the thread-taking cam 6 is interference-fitted with the thread-taking camshaft sleeve 17.

[0047] Preferably, see Figure 7 The wire guide frame 7 is provided with a sliding rail 702 and a threaded hole 703 on both the side near the housing 4 and the side away from the housing 4. The inner wire hook 8 and the outer wire hook 9 are provided with a U-shaped snap-fit ​​end F and a strip-shaped positioning groove G. The U-shaped snap-fit ​​end F can be slidably snapped on the sliding rail 702. The threaded fastener passes through the strip-shaped positioning groove G and is connected to the threaded hole 703.

[0048] When it is necessary to adjust the position of the inner wire hook 8 and / or the outer wire hook 9, the threaded fastener can be unscrewed from the threaded hole 703 of the wire guide frame 7, and then the inner wire hook 8 and / or the outer wire hook 9 can be slid along the sliding track 702 of the wire guide frame 7 to the appropriate position. After that, the threaded fastener can be re-passed through the strip positioning groove G and screwed into the threaded hole 703 to complete the position adjustment of the inner wire hook 8 and / or the outer wire hook 9.

[0049] Preferably, the sliding track 702 extends linearly from the head end of the housing 4 to the base end, thereby enabling precise fine-tuning and compensation of the hook line by adjusting the position of the inner hook 8 and / or the outer hook 9.

[0050] Preferably, see Figure 7 and Figure 10Multiple thread-picking cams 6 are spaced apart. A drive motor 5 drives all thread-picking cams 6 to rotate synchronously around the same axis. A thread guide frame 7 has multiple thread guide plates 18 spaced apart above the clearance groove 701. Each thread guide plate 18 has a hollowed-out center forming a thread-passing hole 1801. When all the thread-picking cams 6 rotate through the clearance groove 701, a thread guide plate 18 exists between any two adjacent thread-picking cams 6. The presence of multiple thread-picking cams 6 increases the thread throughput of the flexible auxiliary thread supply device, better realizing the flexible adjustment of secondary thread supply; while the presence of the thread guide plates 18 improves the thread's trajectory during thread passage.

[0051] Preferably, see Figure 10 When all the thread-picking cams 6 rotate through the clearance groove 701, a gap space H is formed between any two adjacent thread-picking cams 6, and the thread-passing piece 18 between any two adjacent thread-picking cams 6 divides the gap space H equally, so that the surface line moves better when passing through the line.

[0052] Better, see Figure 7 , Figure 8 and Figure 10 In this embodiment, there are two thread-picking cams 6 spaced apart. When threading, the top thread first passes through the inner thread hook 8, then passes through the thread-passing hole 1801 hollowed out in the middle of the thread-passing piece 18, and then passes through the outer thread hook 9.

[0053] Preferably, in this embodiment, the thread-taking camshaft sleeve 17 of the thread-taking camshaft 11 is fitted with a thread-taking cam washer between two adjacent thread-taking cams 6, thereby axially limiting the thread-taking cam 6.

[0054] See Figure 5 This embodiment also provides an intelligent sewing machine, including a housing 4, a main drive motor, a processor, a thread take-up mechanism, and the aforementioned flexible auxiliary thread supply device. The housing 4 has a distance sensor 19, a left thread hook M, and a right thread hook N arranged at the head end. The thread take-up mechanism has a thread take-up rod 3 with the thread hole E extending out of the housing 4. The main drive motor drives the thread take-up rod 3 to move up and down reciprocally through the main shaft. The thread take-up cam 6 and the thread guide 7 are both arranged on the side of the thread take-up rod 3 facing the base end of the housing 4. The processor is simultaneously connected to the distance sensor 19, the main drive motor, and the drive motor 5.

[0055] The intelligent sewing machine in this embodiment can detect and sense changes in fabric thickness through distance sensor 19. In conjunction with the independent drive source of the flexible auxiliary thread supply device, it flexibly controls the secondary thread take-up process, changes the specific shape of the sewing machine's thread supply curve, and achieves the effect of adaptive sewing of thin and thick materials. This can reduce thread tension and improve the stability, flatness, and aesthetics of the fabric stitches.

[0056] Preferably, in this embodiment, the distance sensor 19 on the smart sewing machine is a laser sensor.

[0057] As described in the aforementioned background technology, the amount of thread supplied is determined by the relative positions of the take-up lever and the left and right hooks. In this embodiment, the intelligent sewing machine, after introducing a flexible auxiliary thread supply device, is equivalent to adding a thread guide point between the take-up lever 3 and the right hook N. The specific principle for calculating the amount of thread supplied is as follows: [See...] Figure 11 The thread passes sequentially through the right hook N, the flexible auxiliary thread supply device P, the thread hole E of the take-up lever 3, and the left hook M. During operation, when the spatial position of the thread hole E on the take-up lever 3 changes continuously, and the flexible auxiliary thread supply device P is not working, the lengths of thread segments EM and EP change, while the length of thread segment PN remains unchanged. The lengths of these three segments are denoted as L. EM L EP and L PN The sum of the three line segments is denoted as R. （φ） =L EM +L EP +L PN Where φ is the principal axis rotation angle, and R is the rotation angle. （φ） It varies with the value of φ. During a work cycle in which the flexible auxiliary cable supply device P is not operating, when the cable through hole E is at its highest point, R... （φ） It has a maximum value R （φ）max Maximum value R （φ）max Subtract the sum R of the line segments at a certain moment （φ） The excess thread can be used to form thread loops, which rotate around the rotary hook to form thread stitches. This difference is the thread supply ΔR. （φ） =R （φ）max -R （φ） When the flexible auxiliary cable supply device P operates and pulls the cable downwards, the length of the line segment between the right hook N and the flexible auxiliary cable supply device P increases, equivalent to increasing from the original length L. PN Transform into L PN′ R （φ） Increase, R （φ）max If ΔR is a constant, then （φ） The amount of wire supplied decreases as the wire take-up cam 6 takes up the wire, and conversely, the amount of wire supplied increases when the wire take-up cam 6 rotates from the wire take-up position to the normal position.

[0058] It should be noted that due to the diverse nature of modern sewing scenarios, different thread quantity curves theoretically correspond to requirements such as fabric thickness and stitch length. Through preliminary theoretical analysis and experimental verification, different thread quantity curves can be matched with suitable thread supply curves to adapt to different sewing scenarios. In this embodiment, the intelligent sewing machine records and stores different thread supply and demand matching relationships in a thread quantity database. Simultaneously, a drive source control logic database corresponding one-to-one with different thread supply quantities is established based on theoretical motion calculation data and also stored in the intelligent sewing machine. When the worker inserts the fabric into the presser foot and compacts it, the intelligent sewing machine can detect the fabric thickness using a laser sensor. Combined with the pre-set stitch length, it can automatically calculate the thread quantity required, then search the thread quantity database for a matching thread supply quantity. This is then linked to the corresponding drive source control logic in the control logic database. The processor issues instructions to control the drive source to update the take-up cam 6, thus adjusting the thread supply.

[0059] For example, see Figures 8 to 10 In the case of sewing thick fabrics with a large stitch pitch, the initial step is to adjust the inner and outer thread hooks of the flexible auxiliary thread supply device to a suitable position. Once the fabric is pressed and the thickness is detected by a laser sensor, the processor automatically controls the rotation of the thread take-up cam 6: within the spindle angle range of 0° to 90°, the thread take-up cam 6 is controlled to rotate to the normal position to increase the thread supply and thus encompass the required thread amount curve; within the spindle angle range of 90° to 150°, the thread take-up cam 6 is controlled to rotate to the thread take-up position to decrease the thread supply, while still encompassing the required thread amount curve and trying to get as close to it as possible; within the spindle angle range of 150° to 360°, the thread take-up cam 6 is controlled to rotate to the normal position to increase the thread supply and thus encompass the required thread amount curve. This control method is the corresponding... Figure 12 When sewing with the "non-sinusoidal" thread supply of curve IV, it can be seen that curves II and IV have no interference in regions a, b, and c, which is an ideal state of matching the supply and demand of thread.

[0060] Traditional four-bar thread take-up mechanisms can only achieve a "quasi-sine" thread supply, with the remaining thread quantity typically fluctuating. The difference between curve IV and curve II remains relatively constant across each stage. This leads to problems when sewing thin elastic fabrics (such as skin-lined clothing and yoga wear) and medium- to slightly thicker fabrics (such as denim). Traditional four-bar mechanisms are prone to thread spillage due to excessive excess thread, or thread breakage due to insufficient excess thread, resulting in poor sewing quality. Therefore, [the following text is incomplete and requires further context: "adopting..."] Figure 12When sewing thin fabrics, the thread supply of the medium curve IV type can ensure that the thread supply at any given time is 10% to 20% greater than the required thread supply. This means the excess thread remains stable within a reasonable range without significant fluctuations, contributing to smoother and more aesthetically pleasing stitches, reduced thread tension, and a lower breakage rate. Furthermore, since the flexible auxiliary thread supply device in this embodiment does not suffer from the parameter limitations of a four-bar linkage thread take-up mechanism, theoretically, the peak value and width of the thread supply curve can be freely adjusted by changing the size and shape of the take-up cam's outer contour and the control logic, greatly improving the possibility of a reasonable match between the supply and demand of thread.

[0061] For example, when sewing thick or extra-thick materials (such as fleece-lined denim), the maximum amount of thread required during the sewing process usually reaches 110mm to 120mm, and the maximum amount of thread supplied needs to reach 115mm to 125mm. In other words, the longitudinal stroke of the thread take-up lever's thread hole needs to reach 68mm to 75mm. Traditional four-bar linkage thread take-up mechanisms can hardly achieve this thread take-up stroke due to limited space in the sewing head and other reasons.

[0062] The flexible auxiliary cable supply device in this embodiment can meet this condition. See also Figures 8 to 10 Initially, the inner and outer thread hooks on the flexible auxiliary thread supply device are adjusted to a suitable position. Once the fabric is pressed and the thickness is detected by a laser sensor, the processor automatically controls the rotation of the thread take-up cam 6: within the spindle angle range of 0° to 210°, the cam 6 is controlled to rotate to the normal position to increase the thread supply and thus encompass the required thread quantity curve; within the spindle angle range of 210° to 260°, the cam 6 is controlled to first rotate to the take-up position and then to the normal position, maintaining a stable thread supply while encompassing the required thread quantity curve; within the spindle angle range of 260° to 360°, the cam 6 continues to rotate to the normal position to further increase the thread supply and thus encompass the required thread quantity curve. This control method is called… Figure 13 When sewing with a non-sinusoidal thread supply of curve IV, it can be seen that curves II and IV do not interfere with each other in regions a, b, and c, representing another ideal state of thread supply and demand matching. Under this supply and demand matching relationship, sufficient thread supply can be achieved in regions a, b, and c, resulting in smoother and more aesthetically pleasing stitches when sewing thick and extremely thick materials, reduced thread tension, and a lower breakage rate.

[0063] The examples above illustrate the adjustment method of the flexible auxiliary thread supply device when the fabric thickness remains uniform. Even in situations where the fabric thickness changes suddenly, such as during over- or under-stitching, the laser sensor can still detect these changes in advance and feed them back to the processor to make decisions about increasing or decreasing the thread supply. Finally, the flexible auxiliary thread supply device executes the corresponding commands, ensuring good stitch quality at the over- and under-stitching points. Compared to the traditional four-bar linkage thread take-up mechanism, which requires removing the end cap for manual adjustment resulting in low efficiency and accuracy, the flexible auxiliary thread supply device in this embodiment allows for fully automatic, real-time, and high-precision adjustment of the sewing equipment. It is simpler and more convenient, improving the efficiency of the operator.

[0064] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A flexible auxiliary wire supply device, characterized in that, The sewing machine includes a drive motor (5), a take-up cam (6), and a thread guide frame (7). The drive motor (5) is located inside the housing (4) of the sewing machine. The drive motor (5) independently drives the take-up cam (6) outside the housing (4) to rotate around the axis through a transmission mechanism. The thread guide frame (7) is located outside the housing (4) and below the take-up cam (6). The thread guide frame (7) has a clearance groove (701) in the middle position for the take-up cam (6) to pass through when rotating. The thread guide frame (7) has an inner thread hook (8) on the side close to the housing (4) and an outer thread hook (9) on the side away from the housing (4). The inner thread hook (8) and the outer thread hook (9) are both mounted on the thread guide frame (7) in an adjustable position.

2. The flexible auxiliary wire supply device according to claim 1, characterized in that, The drive shaft of the drive motor (5) is arranged in the same direction as the main shaft of the sewing machine.

3. The flexible auxiliary wire supply device according to claim 1, characterized in that, The transmission mechanism includes a transmission shaft (10) and a thread-taking cam shaft (11). One end of the transmission shaft (10) is connected to the drive shaft of the drive motor (5) via a synchronous belt transmission sub-mechanism, and the other end of the transmission shaft (10) is connected to the thread-taking cam shaft (11) via a bevel gear transmission sub-mechanism. The thread-taking cam (6) is interference-fitted with the thread-taking cam shaft (11).

4. The flexible auxiliary wire supply device according to claim 1, characterized in that, The wire guide frame (7) is provided with a sliding rail (702) and a threaded hole (703) on both the side near the housing (4) and the side away from the housing (4). The inner wire hook (8) and the outer wire hook (9) are provided with a U-shaped snap-fit ​​end (F) and a strip-shaped positioning groove (G). The U-shaped snap-fit ​​end (F) can be slidably snapped on the sliding rail (702). The threaded fastener passes through the strip-shaped positioning groove (G) and connects to the threaded hole (703).

5. The flexible auxiliary wire supply device according to claim 4, characterized in that, The sliding track (702) extends in a straight line from the head end of the housing (4) to the base end.

6. The flexible auxiliary wire supply device according to claim 1, characterized in that, The thread-picking cams (6) are spaced apart. The drive motor (5) drives all the thread-picking cams (6) to rotate synchronously around the same axis. The thread guide frame (7) is spaced apart above the clearance groove (701) with multiple thread guide pieces (18). The center of each thread guide piece (18) is hollowed out to form a thread-passing hole (1801). When all the thread-picking cams (6) rotate through the clearance groove (701), there is a thread guide piece (18) between any two adjacent thread-picking cams (6).

7. The flexible auxiliary wire supply device according to claim 6, characterized in that, When all the wire-picking cams (6) rotate through the clearance groove (701), a gap space (H) is formed between any two adjacent wire-picking cams (6), and the wire guide plate (18) between any two adjacent wire-picking cams (6) divides the gap space (H) equally.

8. An intelligent sewing machine, characterized in that, The device includes a housing (4), a main drive motor, a processor, a thread take-up mechanism, and a flexible auxiliary thread supply device as described in any one of claims 1-7. The housing (4) has a distance sensor (19), a left thread hook (M), and a right thread hook (N) arranged at the head end. The thread take-up mechanism has a thread take-up rod (3) with the thread through hole (E) extending out of the housing (4). The main drive motor drives the thread take-up rod (3) to move up and down reciprocally through the main shaft. The thread take-up cam (6) and the thread guide frame (7) are both arranged on the side of the thread take-up rod (3) facing the base end of the housing (4). The processor is simultaneously connected to the distance sensor (19), the main drive motor, and the drive motor (5).

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