Sewing machine and control method

Abstract

The sewing machine comprises a synchronous belt transmission mechanism, a tension adjusting mechanism and a detection sensor, the synchronous belt transmission mechanism comprises a main shaft, a lower shaft, a driving wheel, a driven wheel and a synchronous belt, the driving wheel is connected with the main shaft in a limiting mode, and the driven wheel is connected with the lower shaft in a limiting mode; the synchronous belt is arranged on the driving wheel and the driven wheel and is respectively meshed with the driving wheel and the driven wheel; the tensioning adjusting mechanism and the detection sensor are both arranged on the outer side of the synchronous belt and located between the driving wheel and the driven wheel, the tensioning adjusting mechanism comprises a driving part and a tensioning wheel, and the tensioning wheel abuts against the peripheral wall of the synchronous belt and is in transmission connection with the driving part. The tensioning wheel can actively adjust the tightness of the synchronous belt under the driving of the driving part; the detection sensor directly faces the peripheral wall of the synchronous belt and is used for detecting the motion frequency of the synchronous belt and controlling the driving part to work. Therefore, the sewing machine can automatically adjust the motion frequency of the synchronous belt by using the tension adjusting mechanism.

Description

Technical Field

[0001] The present invention belongs to the technical field related to sewing machines, and in particular relates to a sewing machine and a control method thereof. Background Art

[0002] At present, a synchronous belt is usually used to transmit power between the main shaft and the lower shaft of a sewing machine. The specific structure is: a main shaft synchronous pulley is installed on the main shaft, and a lower shaft synchronous pulley is installed on the lower shaft. The synchronous belt is installed on the main shaft synchronous pulley and the lower shaft synchronous pulley, and the tensioning pulley is used to apply appropriate tension to the synchronous belt to ensure the stable operation of the transmission system.

[0003] In a synchronous belt drive system, the belt reaches an optimal frequency during transmission, achieving maximum efficiency and minimal wear. However, during the actual sewing process, the teeth on the synchronous belt experience increased wear due to constant friction, resulting in decreased transmission efficiency or even failure. As the teeth wear, the meshing clearance between them and the synchronous pulley increases. This increased transmission resistance can cause the belt to slip when sewing thicker materials, leading to inaccurate stitch length and poor feed. This necessitates manual readjustment of the tensioner pulley or replacement of the synchronous belt, which not only shortens the belt's lifespan but also compromises production efficiency. Summary of the Invention

[0004] In view of this, it is necessary to provide a sewing machine and a control method for solving the above technical problems.

[0005] A sewing machine, comprising:

[0006] A synchronous belt transmission mechanism includes a main shaft, a lower shaft, a driving wheel, a driven wheel, and a synchronous belt. The driving wheel is mounted on the main shaft and is connected to the main shaft for a limited position. The driven wheel is mounted on the lower shaft and is connected to the lower shaft for a limited position. The synchronous belt is installed on the driving wheel and the driven wheel and meshes with the driving wheel and the driven wheel respectively.

[0007] A tensioning adjustment mechanism is provided on the outside of the synchronous belt and located between the driving pulley and the driven pulley. The tensioning adjustment mechanism includes a driving member and a tensioning pulley. The tensioning pulley abuts against the outer peripheral wall of the synchronous belt and is in transmission connection with the driving member. The tensioning pulley can actively adjust the tightness of the synchronous belt under the drive of the driving member.

[0008] A detection sensor is arranged on the outside of the synchronous belt and located between the driving wheel and the driven wheel, and the detection sensor is arranged opposite to the outer peripheral wall of the synchronous belt, for detecting the movement frequency of the synchronous belt and generating a first feedback signal, and the first feedback signal is used for the operation of the driving member.

[0009] It can be understood that the movement frequency of the synchronous belt is monitored by a detection sensor, and the tightness of the synchronous belt is adjusted in real time with a tensioning wheel to ensure that the movement frequency of the synchronous belt meets the set requirements. On the one hand, this can improve the transmission efficiency of the synchronous belt, reduce wear, and increase the life of the synchronous belt; on the other hand, it can also enable the sewing machine to be adaptively adjusted according to different working conditions, which has the effect of improving the sewing efficiency and sewing effect of the sewing machine.

[0010] In one embodiment, the movement frequency of the synchronous belt is set to f, f=n / t, wherein n is the number of circles of the synchronous belt in the time t.

[0011] In one embodiment, the driving member is configured as a motor, and the tensioning wheel is configured as an eccentric wheel;

[0012] Furthermore, the motor can adjust the tightness of the synchronous belt by controlling the rotation angle of the eccentric wheel.

[0013] It can be understood that the tension of the synchronous belt is adjusted by using a motor to drive the eccentric wheel to rotate, so that the tension adjustment mechanism can adjust the tightness of the synchronous belt in real time through the change of the rotational position of the eccentric wheel. It has the characteristics of rapid response and precise control, and can effectively improve the adjustment efficiency and reliability of the tension adjustment mechanism.

[0014] In one embodiment, the detection sensor is configured as an acoustic wave sensor;

[0015] The acoustic wave sensor is capable of transmitting acoustic waves toward an outer peripheral wall of the synchronous belt and receiving the acoustic waves reflected by the outer peripheral wall of the synchronous belt to generate the first feedback signal.

[0016] In one embodiment, the sewing machine further comprises a controller, wherein the controller is electrically connected to the driving member and the detection sensor respectively;

[0017] Furthermore, the controller can analyze and process the first feedback signal transmitted by the detection sensor to control the operation of the driving member so that the value obtained by the detection sensor after detecting the movement frequency of the synchronous belt is adjusted to a preset target value.

[0018] In one embodiment, the controller has a memory module;

[0019] The memory module can record different working states after the driving member drives the tensioning wheel to adjust. When the driving member is in any of the working states, the number obtained by the detection sensor after detecting the movement frequency of the synchronous belt is a preset target value.

[0020] It can be understood that by storing the different working states of the driving parts through the memory module of the controller, when the sewing machine faces the corresponding working conditions again, the tension adjustment mechanism can realize fast and accurate adjustment of the tightness of the synchronous belt through the records of the memory module. This not only can respond to the tension requirements of the synchronous belt under different working conditions in real time, but also provides a technical basis for the sewing machine to realize intelligent pre-adjustment of the tightness of the synchronous belt, thereby improving the adaptability and ease of operation of the sewing machine.

[0021] In one embodiment, the sewing machine further comprises a laser sensor, the laser sensor being electrically connected to the controller and configured to detect a thickness of a material to be sewn by the sewing machine and generate a second feedback signal;

[0022] Furthermore, the controller can control the driving member to switch to the corresponding working state according to the second feedback signal.

[0023] It can be understood that by pre-detecting the thickness of the sewing material through the laser sensor, the tightness of the synchronous belt of the sewing machine has been adjusted to the corresponding requirements by the tensioning adjustment mechanism before sewing the material, which can further improve the sewing effect of the sewing machine when sewing the material subsequently.

[0024] The present application also provides a control method, which includes the following steps:

[0025] Providing the sewing machine described above;

[0026] The detection sensor detects the movement frequency of the synchronous belt to generate a first feedback signal;

[0027] The driving component controls the tensioning wheel to adjust the tightness of the synchronous belt according to the first feedback signal.

[0028] In one embodiment, the control method further comprises the following steps:

[0029] Recording a working state of the driving member, wherein in the working state, the movement frequency of the synchronous belt is a preset target value;

[0030] detecting the thickness of the material to be sewn by the sewing machine using a laser sensor to generate a second feedback signal;

[0031] The driving member switches to the corresponding working state according to the second feedback signal.

[0032] In one embodiment, the sewing machine has a first state, a second state, and a third state;

[0033] In the first state, when the sewing machine accelerates, the driving member controls the tensioning wheel to increase the tension on the synchronous belt;

[0034] In the second state, when the sewing machine decelerates, the driving member controls the tensioning wheel to reduce the tension on the synchronous belt;

[0035] In the third state, when the thickness of the sewing material sewed by the sewing machine changes, the driving member controls the tensioning wheel to adjust the tensioning force on the synchronous belt until the detection sensor measures that the movement frequency of the synchronous belt is a preset target value.

[0036] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0037] The sewing machine and control method for which protection is sought in the present application use a detection sensor to monitor the movement frequency of the synchronous belt and use a tensioning wheel to adjust the tightness of the synchronous belt in real time, thereby ensuring that the movement frequency of the synchronous belt meets the set requirements. This can, on the one hand, improve the transmission efficiency of the synchronous belt and reduce wear, thereby increasing the life of the synchronous belt; on the other hand, it can also enable the sewing machine to be adaptively adjusted according to different working conditions, thereby improving the sewing efficiency and sewing effect of the sewing machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 This is a schematic diagram of the structure of the sewing machine provided in this application.

[0040] Figure 2 This is a structural schematic diagram of the sewing machine provided in this application from another perspective.

[0041] Figure 3 This is a schematic diagram of the partial structure of the sewing machine provided in this application.

[0042] Figure 4 This is a structural diagram of the synchronous belt transmission mechanism, tensioning adjustment mechanism and detection sensor during assembly in this application.

[0043] Figure 5 for Figure 4 Enlarged view of part A in the middle.

[0044] Figure 6 This is a schematic diagram of the local structure when the eccentric wheel in this application adjusts the tightness of the synchronous belt according to the ultrasonic sensor.

[0045] Figure 7This is a flow chart of the control method provided in this application.

[0046] 1. Sewing machine; 2. Timing belt transmission mechanism; 3. Main shaft; 4. Lower shaft; 5. Driving pulley; 6. Drive pulley; 7. Driven pulley; 8. Timing belt; 9. Outer peripheral wall; 10. Main shaft motor; 11. Tensioning adjustment mechanism; 12. Driving member; 13. Motor; 14. Motor shaft; 15. Tensioning pulley; 16. Eccentric wheel; 17. Detection sensor; 18. Acoustic wave sensor; 19. Fixing bracket; 20. Sewing machine head; 21. First screw; 22. Second screw. DETAILED DESCRIPTION

[0047] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] It should be noted that when an element is referred to as being “provided on” another element, it may be directly provided on the other element or there may be an intermediate element. When an element is considered to be “provided on” another element, it may be directly provided on the other element or there may be an intermediate element. When an element is considered to be “fixed to” another element, it may be directly fixed to the other element or there may be an intermediate element.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] like Figures 1 to 6As shown, the sewing machine 100 provided in the present application includes a synchronous belt transmission mechanism 10, a tensioning adjustment mechanism 20 and a detection sensor 30. The synchronous belt transmission mechanism 10 includes a main shaft 11, a lower shaft 12, a driving wheel 13, a driven wheel 14 and a synchronous belt 15. The driving wheel 13 is mounted on the main shaft 11 and is connected to the main shaft 11 for limiting position. The driven wheel 14 is mounted on the lower shaft 12 and is connected to the lower shaft 12 for limiting position. The synchronous belt 15 is installed on the driving wheel 13 and the driven wheel 14 and is respectively engaged with the driving wheel 13 and the driven wheel 14; the tensioning adjustment mechanism 20 is arranged on the outside of the synchronous belt 15 and is located between the driving wheel 13 and the driven wheel 14. The tensioning mechanism 20 includes a driving member 21 and a tensioning pulley 22. The tensioning pulley 22 is against the outer peripheral wall 151 of the synchronous belt 15 and is connected to the driving member 21 in transmission. The tensioning pulley 22 can actively adjust the tightness of the synchronous belt 15 under the drive of the driving member 21. The detection sensor 30 is arranged on the outside of the synchronous belt 15 and is located between the driving pulley 13 and the driven pulley 14. In addition, the detection sensor 30 is arranged opposite to the outer peripheral wall 151 of the synchronous belt 15 for detecting the movement frequency of the synchronous belt 15 and generating a first feedback signal. The first feedback signal is used for the operation of the driving member 21. Here, the main shaft 11 and the lower shaft 12 are both rotatably mounted on the housing 40 of the sewing machine, wherein the main shaft 11 can be specifically driven by a main shaft motor 16 mounted on the housing 40, so that while the main shaft 11 is driven to rotate, the main shaft motor 16 drives the lower shaft 12 to rotate under the drive of the driving wheel 13, the synchronous belt 15 and the driven wheel 14, so as to achieve the purpose of controlling the rotation of the shuttle (not shown in the figure) in the sewing machine 100.

[0051] As can be seen from the above, when the sewing machine 100 of the present application is working, the detection sensor 30 is used to monitor the movement frequency of the synchronous belt 15, and the tensioning wheel 22 is used to adjust the tightness of the synchronous belt 15 in real time, so as to ensure that the movement frequency of the synchronous belt 15 meets the set requirements. On the one hand, this can improve the transmission efficiency of the synchronous belt 15 and reduce wear, which has the effect of increasing the life of the synchronous belt 15; on the other hand, it can also enable the sewing machine 100 to be adaptively adjusted according to different working conditions, which has the effect of improving the sewing efficiency and sewing effect of the sewing machine 100.

[0052] In the present application, the movement frequency of the synchronous belt 15 is set to f, where f = n / t, where n is the number of circular revolutions of the synchronous belt 15 within the time t. It is understood that as the driving pulley 13 drives the driven pulley 14 to rotate via the synchronous belt 15, the pressure on the synchronous belt 15 changes, causing the synchronous belt 15 to oscillate during power transmission. The frequency of this oscillation of the synchronous belt 15 is the aforementioned movement frequency of the synchronous belt 15. It should be noted that in existing sewing machines, the synchronous belt 15 has an optimal movement frequency. For example, the optimal movement frequency of a compound feed sewing machine is 95 Hz.

[0053] like Figure 5 、 Figure 6 As shown, in one embodiment, the driving member 21 is configured as a motor 211, and the tensioning pulley 22 is configured as an eccentric wheel 221. Furthermore, the motor 211 is capable of adjusting the tension of the synchronous belt 15 by controlling the rotation angle of the eccentric wheel 221. In other words, the tensioning mechanism 20 of this embodiment adjusts the tension of the synchronous belt 15 by rotating the eccentric wheel 221 driven by the motor 211. This allows the tensioning mechanism 20 to adjust the tension of the synchronous belt 15 in real time by changing the rotational position of the eccentric wheel 221. This provides rapid response and precise control, effectively improving the adjustment efficiency and reliability of the tensioning mechanism 20. It is understood that in other embodiments, the driving member 21 may be configured as a rotary cylinder, and the tensioning pulley 22 may be configured as a cam. Alternatively, the driving member 21 may be configured as a mechanical adjustment mechanism that controls the rotation of an electromagnet. This will not be elaborated upon here.

[0054] like Figure 5 As shown, in this embodiment, the eccentric wheel 221 is mounted on the motor shaft 2111 of the motor 211 through an eccentric hole (not shown) and is fixed with a first screw 101. Here, the motor 211 is partially inserted into the housing 40 and fixedly connected to the housing 40, thereby achieving the assembly connection of the tension adjustment mechanism 20 on the housing 40.

[0055] like Figure 5 、 Figure 6 As shown, in one embodiment, the detection sensor 30 is configured as an acoustic wave sensor 31; the acoustic wave sensor 31 is capable of transmitting acoustic waves toward the outer peripheral wall 151 of the synchronous belt 15 and receiving the acoustic waves reflected by the outer peripheral wall 151 of the synchronous belt 15 to generate a first feedback signal. In other words, this embodiment can detect the movement frequency of the synchronous belt 15 by detecting the swing of the portion of the synchronous belt 15 aligned with the acoustic wave sensor 31. Here, the acoustic wave sensor 31 is specifically arranged in the middle position between the driving pulley 13 and the driven pulley 14, and the acoustic wave sensor 31 is specifically arranged to align with the outer peripheral wall 151 of the synchronous belt 15 at an angle of 89°, 90°, or 91°. It is understood that in other embodiments, the detection sensor 30 can also be configured as a photoelectric switch or other sensor that can be used for distance measurement, which will not be elaborated here.

[0056] like Figure 1 、 Figure 2 and Figure 5 As shown, in this embodiment, the housing 40 is mounted with a fixing bracket 32 ​​via two second screws 102 , and the acoustic wave sensor 31 is fixedly mounted on the fixing bracket 32 ​​, thereby achieving assembly connection of the acoustic wave sensor 31 on the housing 40 .

[0057] In one embodiment, the sewing machine 100 further includes a controller (not shown), which is electrically connected to the driving member 21 and the detection sensor 30. The controller is capable of analyzing and processing the first feedback signal transmitted by the detection sensor 30 to control the operation of the driving member 21 so that the value obtained by the detection sensor 30 after detecting the motion frequency of the synchronous belt 15 is adjusted to a preset target value. Here, the preset target value specifically refers to the value corresponding to the motion frequency of the synchronous belt 15 being at the optimal motion frequency.

[0058] In this embodiment, the controller has a memory module (not shown); the memory module is capable of recording the different operating states after the drive member 21 drives the tensioning wheel 22 to adjust. When the drive member 21 is in any operating state, the value obtained by the detection sensor 30 after detecting the movement frequency of the synchronous belt 15 is the preset target value. In other words, this embodiment can use the memory module of the controller to record the different operating states of the drive member 21, so that when the sewing machine 100 faces the corresponding working conditions again, the tension adjustment mechanism 20 can quickly and accurately adjust the tightness of the synchronous belt 15 through the records in the memory module. This not only enables real-time response to the tension requirements of the synchronous belt 15 under different working conditions, but also provides a technical basis for the sewing machine 100 to achieve intelligent pre-adjustment of the tightness of the synchronous belt 15, thereby improving the adaptability and ease of operation of the sewing machine 100. Here, the working state of the driving member 21 mentioned above specifically refers to the rotation angle of the driving member 21 when the sewing machine 100 drives the tensioning wheel 22 to rotate in order to cope with different working conditions and needs to use the tensioning adjustment mechanism 20 to actively adjust the tightness of the synchronous belt 15 until the movement frequency of the synchronous belt 15 detected by the detection sensor 30 is adjusted to the preset target value.

[0059] In one embodiment, the sewing machine 100 further includes a laser sensor (not shown), which is electrically connected to the controller for detecting the thickness of the material to be sewn by the sewing machine 100 and generating a second feedback signal; and the controller can control the drive member 21 to switch to a corresponding working state according to the second feedback signal. In other words, this embodiment can use a laser sensor to pre-detect the thickness of the material, so that the tightness of the synchronous belt 15 of the sewing machine 100 has been adjusted to the corresponding requirement by the tensioning adjustment mechanism 20 before sewing the material, which can further improve the sewing effect of the sewing machine 100 when sewing the material subsequently. Here, as Figure 1 、 Figure 3 As shown, the laser sensor is mounted on the sewing head 50 of the sewing machine 100 .

[0060] It should be noted that when the sewing machine 100 of this embodiment is in operation, a laser sensor can be used to detect changes in the thickness of the sewing material in advance. Specifically, the thickness of the sewing material to be sewn can be detected in advance, and the distance between the needle and the point where the sewing material changes can be detected in advance. For example, when the sewing machine 100 detects a change in the thickness of the sewing material for the first time, the controller's memory module can first record the rotation angle of the motor 211 when the eccentric wheel 221 is rotated. The operator can observe the sewing effect and, if stitch skipping or thread breakage is found at that point, reset the motion frequency f. The next time the sewing machine 100 detects the same change in the thickness of the sewing material as the first time, the motor 211 can react by changing its angle in advance. The detection sensor 30 then detects the motion frequency of the timing belt 15 and feeds it back to the controller. If the motion frequency f of the timing belt meets the requirements, there is no need to adjust the angle of the motor 211. If the motion frequency f still falls short, the motor 211 angle can be fine-tuned to meet the set requirements. This can achieve better sewing results with the sewing machine 100.

[0061] like Figure 7 As shown, the present application also provides a control method, which includes the following steps:

[0062] Providing the sewing machine 100 described above;

[0063] The detection sensor 30 detects the movement frequency of the synchronous belt 15 to generate a first feedback signal;

[0064] The driving member 21 controls the tensioning wheel 22 to adjust the tightness of the synchronous belt 15 according to the first feedback signal.

[0065] like Figure 7 As shown, in one embodiment, the control method further includes the following steps:

[0066] Recording the working state of the driving member 21, in which the movement frequency of the synchronous belt 15 is a preset target value;

[0067] Using a laser sensor to detect the thickness of the material to be sewn by the sewing machine 100 to generate a second feedback signal;

[0068] The driving member 21 switches to a corresponding working state according to the second feedback signal.

[0069] In the present application, the sewing machine 100 of the present application has a first state, a second state, and a third state. In the first state, when the sewing machine 100 accelerates, the driver 21 controls the tensioning wheel 22 to increase the tension on the synchronous belt 15. In the second state, when the sewing machine 100 decelerates, the driver 21 controls the tensioning wheel 22 to reduce the tension on the synchronous belt 15. In the third state, when the thickness of the sewing material being sewn by the sewing machine 100 changes, the driver 21 controls the tensioning wheel 22 to adjust the tension on the synchronous belt 15 until the detection sensor measures the motion frequency of the synchronous belt 15 at a preset target value. In other words, the sewing machine 100 of the present application can automatically and adaptively adjust the motion frequency of the synchronous belt 15 using the tensioning mechanism 20 when accelerating, decelerating, or when the sewing material thickness changes, thereby improving the sewing efficiency and sewing effect of the sewing machine 100. Here, acceleration and deceleration of the sewing machine 100 specifically refers to the acceleration and deceleration of the rotation of the main shaft 11 of the sewing machine 100.

[0070] When the sewing machine 100 of the present application is turned on, the spindle 11 of the sewing machine 100 increases from 0 rpm to the set rpm (for example, 2000 rpm), and due to the rapid change in rpm, the driving wheel 13 drives the synchronous belt 15 from a static state to a dynamic state. As the power increases, the tension on the synchronous belt 15 increases rapidly. Due to the friction between the synchronous belt 15 and the driving wheel 13 and the driven wheel 14, a greater torque is transmitted, thereby accelerating the sewing machine 100. At the same time, as the rpm continues to increase, the running speed of the synchronous belt 15 on the driving wheel 13 and the driven wheel 14 increases, and the centrifugal force causes the synchronous belt 15 to deform and lengthen. Wherein, the total length of the synchronous belt 15 is set to P, the original length of the synchronous belt 15 is set to X, and the length of the synchronous belt when it is stretched is set to Y. In this way, the length of the synchronous belt 15 when accelerating is P = X + Y; and the length of the synchronous belt 15 when it is stationary is P = X.

[0071] Here, when the length of the synchronous belt 15 becomes longer, the synchronous belt 15 is stretched, the synchronous belt 15 is in a loose state as a whole, and the swing amplitude of the synchronous belt 15 becomes larger; since the movement frequency f of the synchronous belt 15 is f = n / t, when the speed remains unchanged, the synchronous belt 15 is stretched, the time taken for the synchronous belt 15 to make one circle as a whole becomes longer, n decreases, and t remains unchanged, which makes the movement frequency f of the synchronous belt 15 smaller; for this reason, the driving member 21 drives the tensioning wheel 22 to tension the synchronous belt 15 inward and increases the tensioning force of the tensioning wheel 22 on the synchronous belt 15 to reduce the range of vibration of the synchronous belt 15 and increase the movement frequency f of the synchronous belt 15, so that the synchronous belt 15 can normally fit the driving wheel 13 and the driven wheel 14, stabilize the transmission efficiency of the synchronous belt 15, and prevent the occurrence of wear caused by deformation of the synchronous belt 15.

[0072] When the sewing machine 100 of the present application is in the process of sewing, once the thickness of the sewing material changes, for example, when the sewing machine 100 needs to sew thicker sewing materials, the required transmission force increases, and the required torque increases to reach the original rotation speed. At this time, the torque of the main shaft motor 16 remains unchanged, that is, the sewing machine 100 outputs the same torque at the same speed when sewing thin materials and thick materials. When sewing thick materials, the thick material will squeeze the presser foot spring (not shown) on the sewing machine 100, increasing the pressure on the feed teeth (not shown). Since the torque cannot be increased to the required requirement, the feeding speed of the lower shaft 12 slows down, making the transmission speed between the main shaft 11 and the lower shaft 12 asynchronous, and there is a synchronous belt 15 and the driving wheel 13 and the driven wheel 14. There is a situation of misaligned teeth or even slipping. At this time, the speed of the lower shaft 12 is reduced, resulting in the main shaft 11 rotating unchanged during sewing, and the speed of the lower shaft 12 becomes smaller. The needle driven by the main shaft 11 (not shown) and the hooking angle of the rotary hook driven by the lower shaft 12 cannot be perfectly matched, and the hooking effect is unsatisfactory, which will cause situations such as stitch skipping and thread breakage. At this time, the speed of the lower shaft 12 is reduced, and the movement frequency should be reduced. The control method of the present application, combined with the detection sensor 30, adjusts the rotation angle of the motor 211 according to the change of the movement frequency of the synchronous belt 15, and adjusts the eccentric wheel 221 to achieve the set movement frequency of the synchronous belt 15, so as to achieve the effect of precise sewing, avoid the situation of misaligned teeth, and increase the service life of the synchronous belt 15.

[0073] When the sewing machine 100 encounters a jam during sewing, some operators will slow down before passing the jam, such as quickly reducing the speed from 3000 rpm to 500 rpm. At this time, the centrifugal force of the synchronous belt 15 becomes smaller, which will shorten the deformation of the synchronous belt 15, and the movement frequency f of the synchronous belt 15 becomes larger accordingly. When the detection sensor 30 detects that the movement frequency f of the synchronous belt 15 does not meet the preset target value, the motor 211 rotates the angle to reduce the tension of the eccentric wheel 221 on the synchronous belt 15, increase the movement frequency f, and meet the set preset target value requirements.

[0074] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present invention and are not intended to limit the present invention. Any appropriate changes and modifications to the above embodiments are intended to fall within the scope of protection claimed by the present invention as long as they are within the spirit of the present invention.

Claims

1. A sewing machine, characterized in that: The sewing machine (100) comprises: A synchronous belt transmission mechanism (10) comprises a main shaft (11), a lower shaft (12), a driving wheel (13), a driven wheel (14) and a synchronous belt (15), wherein the driving wheel (13) is sleeved on the main shaft (11) and connected to the main shaft (11) for limiting position, the driven wheel (14) is sleeved on the lower shaft (12) and connected to the lower shaft (12) for limiting position, and the synchronous belt (15) is installed on the driving wheel (13) and the driven wheel (14) and meshes with the driving wheel (13) and the driven wheel (14) respectively; A tensioning adjustment mechanism (20) is arranged on the outside of the synchronous belt (15) and located between the driving wheel (13) and the driven wheel (14). The tensioning adjustment mechanism (20) includes a driving member (21) and a tensioning wheel (22). The tensioning wheel (22) abuts against the outer peripheral wall (151) of the synchronous belt (15) and is in transmission connection with the driving member (21). The tensioning wheel (22) can actively adjust the tightness of the synchronous belt (15) under the driving of the driving member (21); A detection sensor (30) is arranged outside the synchronous belt (15) and located between the driving wheel (13) and the driven wheel (14), and the detection sensor (30) is arranged opposite to the outer peripheral wall (151) of the synchronous belt (15) and is used to detect the movement frequency of the synchronous belt (15) and generate a first feedback signal, wherein the first feedback signal is used for the operation of the driving member (21).

2. The sewing machine according to claim 1, characterized in that The movement frequency of the synchronous belt (15) is set to f, f=n / t, wherein n is the number of circles of the synchronous belt (15) in the time t.

3. The sewing machine according to claim 1, wherein The driving member (21) is configured as a motor (211), and the tensioning wheel (22) is configured as an eccentric wheel (221); Furthermore, the motor (211) can adjust the tightness of the synchronous belt (15) by controlling the rotation angle of the eccentric wheel (221).

4. The sewing machine according to claim 1, wherein The detection sensor (30) is configured as an acoustic wave sensor (31); The acoustic wave sensor (31) is capable of transmitting acoustic waves toward the outer peripheral wall (151) of the synchronous belt (15), and receiving the acoustic waves reflected by the outer peripheral wall (151) of the synchronous belt (15) to generate the first feedback signal.

5. The sewing machine according to claim 1, characterized in that The sewing machine (100) further includes a controller, wherein the controller is electrically connected to the driving member (21) and the detection sensor (30) respectively; Furthermore, the controller is capable of analyzing and processing the first feedback signal transmitted by the detection sensor (30) to control the operation of the driving member (21) so that the value obtained by the detection sensor (30) after detecting the movement frequency of the synchronous belt (15) is adjusted to a preset target value.

6. The sewing machine according to claim 5, characterized in that The controller has a memory module; The memory module is capable of recording different working states after the driving member (21) drives the tensioning wheel (22) to adjust. When the driving member (21) is in any of the working states, the number obtained by the detection sensor (30) after detecting the movement frequency of the synchronous belt (15) is a preset target value.

7. The sewing machine according to claim 6, characterized in that The sewing machine (100) further comprises a laser sensor, the laser sensor being electrically connected to the controller and being used to detect the thickness of the material to be sewn by the sewing machine (100) and generate a second feedback signal; Furthermore, the controller can control the driving member (21) to switch to the corresponding working state according to the second feedback signal.

8. A control method, characterized in that: The control method includes the following steps: Provided is a sewing machine (100) according to any one of claims 1 to 7; The detection sensor (30) detects the movement frequency of the synchronous belt (15) to generate a first feedback signal; The driving member (21) controls the tensioning wheel (22) to adjust the tightness of the synchronous belt (15) according to the first feedback signal.

9. The control method according to claim 8, characterized in that: The control method further comprises the following steps: Recording the working state of the driving member (21), wherein in the working state, the movement frequency of the synchronous belt (15) is a preset target value; Using a laser sensor to detect the thickness of the material to be sewn by the sewing machine (100) to generate a second feedback signal; The driving member (21) switches to the corresponding working state according to the second feedback signal.

10. The control method according to claim 8, characterized in that: The sewing machine (100) has a first state, a second state and a third state; In the first state, when the sewing machine (100) is accelerated, the driving member (21) controls the tensioning wheel (22) to increase the tensioning force on the synchronous belt (15); In the second state, when the sewing machine (100) decelerates, the driving member (21) controls the tensioning wheel (22) to reduce the tensioning force on the synchronous belt (15); In the third state, when the thickness of the sewing material being sewn by the sewing machine (100) changes, the driving member (21) controls the tensioning wheel (22) to adjust the tensioning force on the synchronous belt (15) until the detection sensor (30) measures that the movement frequency of the synchronous belt (15) is a preset target value.

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