Thread suction device and thread suction method

Abstract

The invention discloses a thread suction device and a thread suction method, and relates to the technical field of sewing machines, and the thread suction device comprises a material suction pipe, an air pressure driving part, a negative pressure generator and an air source assembly. The material suction pipe is used for sucking the upper thread at the upper thread residual position, and the air pressure driving part is connected with the material suction pipe and used for driving the material suction pipe to move in the direction close to or away from the upper thread residual position; the negative pressure generator is communicated with the material suction pipe and is used for generating negative pressure, so that the material suction pipe sucks the upper thread at the upper thread residual position; the air source assembly is connected with the air pressure driving part and the negative pressure generator through pipelines, and the air source assembly is used for providing an air source for the air pressure driving part and the negative pressure generator so as to control the air pressure driving part and the negative pressure generator to work. The thread suction device can reduce the production cost while solving the problem of upper thread residue.

Description

Technical Field

[0001] The present application relates to the technical field of sewing machines, and in particular to a thread suction device and a thread suction method. Background Art

[0002] In the sewing industry, to ensure smooth and attractive seams, a presser foot is often added to hold down the fabric. During operation, the needle and presser foot descend synchronously, with the presser foot pressing down on the fabric to prevent it from shifting, ensuring smooth and attractive seams.

[0003] Currently, to address the issue of upper thread residue during the sewing process, a thread sweeping mechanism is used to continuously clean the thread ends, thereby improving sewing quality. Since some fabrics require manual placement, the thread sweeping mechanism interferes with this placement and can easily cause hand injuries. Therefore, some models on the market often remove the thread sweeping mechanism and instead use an electronic thread clamp to address the issue of upper thread residue caused by the presser foot. However, electronic thread clamps exert high pressure during use and are easily damaged, requiring frequent replacement, which increases production costs. Summary of the Invention

[0004] The purpose of this application is to provide a thread suction device and a thread suction method, which can solve the problem of surface thread residue and reduce production costs.

[0005] To achieve the above objectives, the present application provides a thread suction device, comprising:

[0006] Suction tube, used to suck up the remaining upper thread;

[0007] A pneumatic drive component is connected to the material suction pipe and is used to drive the material suction pipe to move toward or away from the residual position of the upper thread;

[0008] a negative pressure generator, connected to the material suction pipe, for generating negative pressure so that the material suction pipe can suck up the upper thread at the remaining position of the upper thread;

[0009] The air source component is connected to the air pressure driving component and the negative pressure generator through pipelines respectively, and is used to provide air source to the air pressure driving component and the negative pressure generator to control the operation of the air pressure driving component and the negative pressure generator.

[0010] In some embodiments, the thread aspirating device further comprises:

[0011] A first control valve is provided on the pipeline between the air source component and the pneumatic drive component, and is used to control the on-off of the pipeline between the air source component and the pneumatic drive component;

[0012] The second control valve is provided on the pipeline between the gas source component and the negative pressure generator, and is used to control the on-off of the pipeline between the gas source component and the negative pressure generator;

[0013] The control module is communicatively connected with the first control valve, the second control valve, the pneumatic drive component and the negative pressure generator, and is used to control the operation of the first control valve, the second control valve, the pneumatic drive component and the negative pressure generator.

[0014] In some embodiments, a pressure sensor is provided at the negative pressure output end of the negative pressure generator. The pressure sensor is used to detect the negative pressure value in the suction pipe and transmit the detection signal to the control module.

[0015] In some embodiments, the pneumatic drive component is a telescopic drive assembly, which includes a cylinder and a telescopic rod. The telescopic rod is connected to the suction pipe to drive the suction pipe to switch between an extended state and a retracted state.

[0016] In some embodiments, the thread aspirating device further comprises:

[0017] A fixed sleeve connecting the telescopic rod and the suction tube;

[0018] The guide sleeve has a guide hole, and the guide hole is matched with the suction pipe to guide the movement of the suction pipe.

[0019] In some embodiments, the suction tube comprises:

[0020] The bent pipe section, including a retractable flexible pipe section, is connected to the negative pressure generator;

[0021] A straight pipe section is connected to the bent pipe section and is slidably engaged with the guide sleeve; and / or

[0022] The bendable corrugated pipe section is arranged at one end of the straight pipe section away from the bent pipe section and is used to adapt to the curved surface structure of the middle presser foot.

[0023] In some embodiments, an elastic reset member is provided between the pneumatic drive member and the suction tube, and the elastic reset member is used to provide an elastic reset force to the suction tube when the pneumatic drive member stops working, so that the suction tube has a tendency to switch from an extended state to a retracted state.

[0024] In some embodiments, the thread suction device further includes a detection module, which is disposed on the suction tube and is used to detect whether the upper thread is completely sucked.

[0025] In some embodiments, a spiral guide groove is provided on the inner wall of the suction tube, and the spiral guide groove is used to guide the surface thread to smoothly enter the suction tube.

[0026] The present application also provides a thread aspirating method, which is applied to any of the above thread aspirating devices, and the thread aspirating method includes:

[0027] After receiving the signal indicating that sewing is finished, the air source is supplied to the pneumatic drive unit through the air source assembly, so that the pneumatic drive unit drives the nozzle of the material suction pipe close to the remaining position of the upper thread;

[0028] The air source component is used to supply air to the negative pressure generator, so that the negative pressure generator generates negative pressure and then sucks the upper thread at the remaining position of the upper thread through the suction pipe;

[0029] After receiving the sewing start signal, the air source is provided to the pneumatic driving component through the air source assembly, so that the pneumatic driving component drives the pipe opening of the material suction pipe away from the residual position of the upper thread.

[0030] Compared to the above background technology, the thread suction device provided in the embodiments of the present application includes a suction pipe, a pneumatic drive, a negative pressure generator, and an air source assembly. The suction pipe is used to suck the surface thread from the remaining surface thread position; the pneumatic drive is connected to the suction pipe and is used to drive the suction pipe to move toward or away from the remaining surface thread position; the negative pressure generator is connected to the suction pipe and is used to generate negative pressure to enable the suction pipe to suck the surface thread from the remaining surface thread position; and the air source assembly is connected to the pneumatic drive and the negative pressure generator respectively via pipelines and is used to provide air to the pneumatic drive and the negative pressure generator to control their operation.

[0031] The working logic specifically includes: after receiving the signal of the end of sewing, providing air source to the pneumatic driving component through the air source component, so that the pneumatic driving component drives the pipe mouth of the suction tube close to the residual position of the upper thread; thereafter, providing air source to the negative pressure generator through the air source component, so that the negative pressure generator generates negative pressure and then absorbs the upper thread at the residual position of the upper thread through the suction tube; after receiving the signal of the start of sewing, providing air source to the pneumatic driving component through the air source component, so that the pneumatic driving component drives the pipe mouth of the suction tube away from the residual position of the upper thread.

[0032] With this setup, the pneumatic drive element moves the suction tube toward or away from the remaining upper thread location, ensuring that the tube's opening is precisely aligned with the remaining upper thread location (such as the presser foot needle hole or the intersection of the stitches). Once the suction tube reaches the designated location, the negative pressure generator generates negative pressure to suck the upper thread from the remaining location, thereby resolving the problem of upper thread residue. Compared to the traditional method of using an electronic thread clamp, this setup avoids the increased production costs associated with frequent replacement of the electronic thread clamp. Furthermore, the negative pressure generator and air source assembly utilize the same air supply, making them more energy-efficient than separate electric systems, significantly reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0034] Figure 1 Schematic diagram of the structure of the thread suction device in the embodiment of the present application.

[0035] Figure 2 Flowchart of the line suction method in an embodiment of the present application.

[0036] in:

[0037] 10-suction pipe, 11-bend pipe section, 12-straight pipe section;

[0038] 20-pneumatic drive element, 21-cylinder body, 22-telescopic rod;

[0039] 30-negative pressure generator;

[0040] 40-gas source assembly;

[0041] 50-first control valve;

[0042] 60- second control valve;

[0043] 70-fixed sleeve;

[0044] 80-Guide sleeve. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0046] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0047] See also Figure 1 The thread suction device provided in the embodiment of the present application includes a material suction tube 10, a pneumatic driving component 20, a negative pressure generator 30 and an air source component 40.

[0048] The suction tube 10 is used to suck up the surface thread at the residual position of the surface thread. The suction tube 10 has a suction nozzle or a suction port. The suction tube 10 can move in the direction close to / away from the residual position of the surface thread (such as the needle hole of the middle presser foot, the intersection of the stitches, this application takes the middle presser foot as an example), ensuring that the suction nozzle is precisely aligned with the residual position of the surface thread, avoiding incomplete suction caused by position deviation of the traditional fixed suction nozzle.

[0049] The pneumatic actuator 20 is connected to the suction tube 10 and is used to move the suction tube 10 toward or away from the remaining needle thread. The pneumatic actuator 20 can be a cylinder or a combination of a pneumatically powered device (such as a pneumatic motor or vacuum cup) and an elastic member.

[0050] The negative pressure generator 30 is connected to the suction pipe 10 and is used to generate negative pressure, allowing the suction pipe 10 to absorb the remaining surface thread. This negative pressure generator 30 typically utilizes the principle of a Venturi tube to generate negative pressure. Specifically, the nozzle of the Venturi tube is connected to the air path of the air source assembly 40, and the negative pressure output end of the Venturi tube is connected to the suction pipe 10. When compressed air passes through a narrow nozzle, the airflow velocity increases significantly. According to Bernoulli's equation, this increase in flow velocity leads to a decrease in pressure, thus generating negative pressure.

[0051] The air source assembly 40 is connected to the pneumatic driving component 20 and the negative pressure generator 30 through pipelines respectively. The air source assembly 40 is used to provide air source to the pneumatic driving component 20 and the negative pressure generator 30 to control the operation of the pneumatic driving component 20 and the negative pressure generator 30.

[0052] The working logic of the thread suction device specifically includes: after receiving the signal that sewing is finished, the air source is provided to the pneumatic driving component 20 through the air source component 40, so that the pneumatic driving component 20 drives the pipe mouth of the suction tube 10 close to the residual position of the upper thread; thereafter, the air source is provided to the negative pressure generator 30 through the air source component 40, so that the negative pressure generator 30 generates negative pressure and then sucks the upper thread at the residual position of the upper thread through the suction tube 10; after receiving the signal that sewing starts, the air source is provided to the pneumatic driving component 20 through the air source component 40, so that the pneumatic driving component 20 drives the pipe mouth of the suction tube 10 away from the residual position of the upper thread.

[0053] With this arrangement, the pneumatic drive 20 drives the suction tube 10 to move toward or away from the remaining surface thread position, ensuring that the nozzle of the suction tube 10 is precisely aligned with the remaining surface thread position. After the suction tube 10 reaches the designated position, the negative pressure generator 30 generates negative pressure to suck the surface thread from the remaining surface thread position, thereby resolving the problem of residual surface thread. Compared to the traditional method of using an electronic thread clamp, the above arrangement avoids the increased production costs caused by the need for frequent replacement of the electronic thread clamp. Furthermore, the negative pressure generator 30 and the air source assembly 40 both use the same air source assembly 40 for air supply, which is more energy-efficient than a separate electric system, thereby significantly reducing production costs.

[0054] In order to facilitate the suction tube 10 to move closer to or away from the residual position of the noodle thread through telescopic movement, the suction tube 10 may include a rigid tube body part and a flexible tube body part. The rigid tube body part (with a suction nozzle or suction port) extends to the residual position of the noodle thread, and the flexible tube body part is connected between the rigid tube body part and the negative pressure generator 30. The flexible tube body part has a telescopic tube body, so that the rigid tube body part can be elastically deformed or flexibly extended during the movement of the rigid tube body part, so that the rigid tube body part can be able to telescopically move relative to the negative pressure generator 30.

[0055] In some embodiments, the thread aspirating device further includes a first control valve 50 , a second control valve 60 , and a control module.

[0056] Among them, the first control valve 50 is arranged on the pipeline between the air source component 40 and the pneumatic drive 20, and the first control valve 50 is used to control the on-off of the pipeline between the air source component 40 and the pneumatic drive 20; the second control valve 60 is arranged on the pipeline between the air source component 40 and the negative pressure generator 30, and the second control valve 60 is used to control the on-off of the pipeline between the air source component 40 and the negative pressure generator 30; the control module is communicatively connected with the first control valve 50, the second control valve 60, the pneumatic drive 20 and the negative pressure generator 30, and the control module is used to control the operation of the first control valve 50, the second control valve 60, the pneumatic drive 20 and the negative pressure generator 30 according to the signal sent by the sewing machine.

[0057] Taking the cylinder as an example, the first control valve 50 is connected to the rod chamber and the rodless chamber of the cylinder through the first pipeline and the second pipeline respectively. In this way, when the air source provided by the air source component 40 enters the rod chamber of the cylinder through the first control valve 50 and the first pipeline, the telescopic rod 22 of the cylinder retracts, and the suction pipe 10 is away from the middle presser foot. When the air source provided by the air source component 40 enters the rodless chamber of the cylinder through the first control valve 50 and the second pipeline, the telescopic rod 22 of the cylinder extends, and the suction pipe 10 is close to the middle presser foot.

[0058] Of course, depending on actual needs, both the first control valve 50 and the second control valve 60 can be solenoid valves, and the control module can be a PLC (programmable logic controller). During operation, after the air source assembly 40 is turned on, the entire machine begins sewing. At the end of sewing, the thread is pre-trimmed. The control module provides a signal to the first control valve 50, causing the cylinder to begin pushing out. After the presser foot is raised and the cylinder is pushed out, the suction pipe 10 is pushed to the designated position. The control module then provides a signal to the second control valve 60, causing the negative pressure generator 30 to start operating, and the thread ends in the presser foot are sucked into the suction pipe 10. When the thread ends are sucked out and the next sewing cycle begins, the second control valve 60 and the negative pressure generator 30 stop operating, and the suction pipe 10 retracts. When the cylinder retracts to a certain position, the machine begins sewing. After the next sewing cycle ends, the machine continues to operate according to the above logic.

[0059] In this way, the control module coordinates the cylinder push, negative pressure start and stop, and sewing action, achieving a fully automated process: thread trimming → thread suction → reset → sewing. This eliminates the need for manual thread cleaning, reduces downtime, and improves production efficiency. For example, the negative pressure generator 30 activates only after the suction tube 10 is in place, avoiding inefficient energy consumption. After thread suction is completed, the cylinder resets immediately, reserving a time window for the next sewing cycle, meeting the high-speed cycle requirements of industrial sewing.

[0060] In some embodiments, a pressure sensor is provided at the negative pressure output end of the negative pressure generator 30 . The pressure sensor is used to detect the negative pressure value in the suction pipe 10 and transmit the detection signal to the control module.

[0061] As can be seen, the pressure sensor continuously monitors the actual negative pressure within the suction pipe 10 and transmits this data in real time to the control module. The control module automatically adjusts the power output of the negative pressure generator 30 accordingly, ensuring that the negative pressure of the negative pressure generator 30 remains stable within the set range, thus preventing insufficient suction force or overload caused by pressure fluctuations.

[0062] In this way, if the suction tube 10 is blocked due to thread entanglement or foreign matter, the pressure sensor will detect an abnormal increase in negative pressure, and the control module will immediately trigger an alarm or suspend the equipment to prevent the motor from being overloaded and damaged; when there is a leak in the pipeline, the negative pressure value of the negative pressure generator 30 is lower than the set threshold, and the control module will automatically increase the power of the negative pressure generator 30 to maintain a stable suction force and avoid functional failure due to sealing failure.

[0063] In some embodiments, the pneumatic drive component 20 is a telescopic drive assembly (specifically a cylinder), which includes a cylinder body 21 and a telescopic rod 22. The telescopic rod 22 is connected to the suction tube 10 to drive the suction tube 10 to switch between an extended state and a retracted state.

[0064] It should be noted that the pneumatic cylinder 21 and the telescopic rod 22 adopt an integrated structure, eliminating intermediate transmission components such as gears and belts, greatly reducing mechanical complexity. Under the same output force, the volume and mass of pneumatic components are much smaller than those of electric systems, which is particularly suitable for the layout of sewing equipment with limited space. At the same time, the suction tube 10 can be directly fixed to the end of the telescopic rod 22 to reduce the risk of loosening of the connector. In addition, the air viscosity of the cylinder is lower than that of hydraulic oil, and the flow resistance is small, which enables the telescopic rod 22 to respond extremely quickly (the entire telescopic process can be completed within 0.1-0.5 seconds). This is crucial for scenarios where the thread ends need to be sucked out immediately after cutting the thread to avoid residual thread ends affecting the next sewing cycle.

[0065] In some embodiments, the thread suction device further includes a fixed sleeve 70 and a guide sleeve 80. The fixed sleeve 70 connects the telescopic rod 22 and the suction tube 10; the guide sleeve 80 (also called a sliding sleeve) has a guide hole that fits through the suction tube 10 to guide its movement.

[0066] In this way, the fixing sleeve 70 rigidly connects the telescopic rod 22 to the suction tube 10, avoiding the risk of loosening of traditional threaded or snap connections. At the same time, the guide hole of the guide sleeve 80 and the suction tube 10 adopt a clearance fit, combined with high-hardness materials (such as hardened steel or ceramic coating), to ensure that the telescopic path of the suction tube 10 is completely consistent each time, and the repeated positioning error is within 0.1mm, thereby limiting the radial shaking of the suction tube 10 through the guide sleeve 80, ensuring the accuracy of the telescopic path of the suction tube 10 each time.

[0067] Of course, according to actual needs, a wavy support plate or a rubber ring can also be provided in the guide sleeve 80. For example, the elastic deformation of the rubber ring can absorb the instantaneous impact force of the piston rod movement, attenuate the collision impact force, and extend the service life of the suction pipe 10.

[0068] In some embodiments, the suction pipe 10 includes a bent pipe section 11 and a straight pipe section 12. The bent pipe section 11 includes a retractable flexible pipe section and is connected to the negative pressure generator 30; the straight pipe section 12 is connected to the bent pipe section 11 and is slidably engaged with the guide sleeve 80.

[0069] For example, the straight pipe section 12 can be a steel pipe or a copper pipe, and the bent pipe section 11 can be a rubber pipe. In this way, the bent pipe section 11 can undergo elastic deformation or flexible expansion and contraction during the expansion and contraction movement of the straight pipe section 12, so that the straight pipe section 12 can expand and contract relative to the negative pressure generator 30.

[0070] In some embodiments, the suction tube 10 also includes a bendable bellows section, which is arranged at one end of the straight tube section 12 away from the bent tube section 11. The bellows section is used to adapt to the curved surface structure of the middle presser foot, so that the suction port of the bellows section is aligned with the position where the surface line needs to be sucked.

[0071] In some embodiments, an elastic reset member is provided between the pneumatic drive member 20 and the suction tube 10, and the elastic reset member is used to provide an elastic reset force to the suction tube 10 when the pneumatic drive member 20 stops working, so that the suction tube 10 has a tendency to switch from an extended state to a retracted state.

[0072] In this embodiment, the pneumatic drive element 20 can be a vacuum generator, and the elastic return element can be a tension spring. The vacuum generator, movable plate, and tension spring are arranged in sequence from a direction away from the negative pressure generator 30 to a direction close to the negative pressure generator 30. The vacuum generator is connected to the movable plate, and one end of the tension spring is fixed and the other end is connected to the movable plate. When suction is required, the air source assembly 40 supplies air to the vacuum generator, which generates negative pressure, causing the movable plate to move away from the negative pressure generator 30. At this time, the tension spring is stretched, accumulating elastic potential energy, and causing the suction tube 10 to extend relative to the negative pressure generator 30 to reach a designated position, ready for suction. After suction is completed, the vacuum generator stops working, the tension spring releases the accumulated elastic potential energy, and the suction tube 10 is pulled back, thereby achieving the purpose of retracting the suction tube 10.

[0073] Of course, according to actual needs, the elastic reset member can be replaced by an organ type sucker in addition to adopting a tension spring. In this way, the telescopic movement of the suction pipe 10 can be achieved by the combination of a vacuum generator and an organ type sucker.

[0074] In some embodiments, the thread suction device further includes a detection module, which is disposed on the suction tube 10 and is used to detect whether the upper thread at the remaining position of the upper thread has been completely sucked.

[0075] In this embodiment, the detection module can be a visual sensor or camera module. For example, the visual sensor can monitor the residual thread in the middle presser foot in real time and generate a residual thread image. The detection module is communicatively connected to the control module. In this way, if the upper thread is not completely absorbed, the control module immediately triggers an alarm or automatically initiates a secondary absorption process, reducing the residual thread rate to nearly 0%.

[0076] In addition, for different thread materials (cotton thread, chemical fiber) or fabric sewing thickness, the detection module can link with the control module to switch the working mode: for example, for thin fabrics, a higher detection frequency is used, that is, switching to high sensitivity mode to prevent thin and soft thread ends from remaining; for example, for thick canvas, the negative pressure intensity is increased, that is, switching to strong suction mode.

[0077] In some embodiments, a spiral guide groove is provided on the inner wall of the suction tube 10 , and the spiral guide groove is used to guide the surface thread to smoothly enter the suction tube 10 .

[0078] It is understood that the spiral guide grooves in the suction pipe 10 can cause the negative pressure airflow to move along a spiral trajectory, thereby generating centripetal acceleration and pushing the lint to flow closely against the pipe wall. This wall adhesion effect can reduce the frictional resistance between the airflow and the pipe wall, increasing the flow rate and shortening the response time for the lint to enter the suction pipe 10 to less than 0.1 seconds. Compared to straight pipes without guide grooves, the airflow is more likely to form turbulence, and the lint is more likely to collide with the pipe wall in a disordered manner, resulting in delayed intake.

[0079] The spiral guide groove also forces thread ends to follow a fixed trajectory, preventing them from accumulating locally on the tube wall. This is especially true for lint-rich materials like cotton and synthetic fibers, where the continuous spiral surface of the spiral guide groove decouples the entanglement of the threads and reduces the likelihood of blockage.

[0080] In some embodiments, a float switch can be installed on the telescopic rod 22 of the cylinder to accurately detect the end position of the telescopic rod 22. When the piston moves to a preset point, the magnetic ring triggers the switch, sending a signal to the control module to ensure that the cylinder movement is strictly executed according to the program.

[0081] In some embodiments, a filter is provided at the end of the suction tube 10 to prevent impurities in the noodles from entering the negative pressure generator 30 .

[0082] The thread suction device using the above-mentioned setting method has a simple structure, a closed-loop logic control, high stability, and does not require excessive operation. At the same time, the integrated electronic thread clamp and the thread sweeping mechanism can be eliminated, thereby avoiding the interference of the thread sweeping mechanism with the placement of the fabric during sewing, and the frequency of parts replacement is low. At the same time, the problem of residual thread ends on the surface of the upper thread is solved, and the subsequent processes are avoided, and the device can operate for a long time.

[0083] See also Figure 2 The present application provides a thread aspirating method, which is applied to the thread aspirating device described in the above specific embodiment; the thread aspirating method includes:

[0084] S1: After receiving the sewing end signal, the air source assembly 40 provides air to the pneumatic driving member 20, so that the pneumatic driving member 20 drives the nozzle of the suction pipe 10 to approach the remaining position of the upper thread;

[0085] S2: The air source assembly 40 provides an air source to the negative pressure generator 30, so that the negative pressure generator 30 generates a negative pressure and then sucks the remaining surface thread through the suction pipe 10;

[0086] S3: After receiving the sewing start signal, the air source assembly 40 provides air to the pneumatic driving member 20 so that the pneumatic driving member 20 drives the pipe opening of the material suction tube 10 away from the residual position of the upper thread.

[0087] Specifically, when the thread suction device is working, the air source assembly 40 is turned on first, and then the whole machine starts sewing. After sewing is completed, the thread is pre-cut, and the control module provides a signal to the first control valve 50, and the cylinder starts to be pushed out. After the presser foot is lifted and the cylinder is pushed out, the suction pipe 10 is pushed to the specified position, and then the control module provides a signal to the second control valve 60, the negative pressure generator 30 starts working, and the thread end in the middle presser foot is sucked by the suction pipe 10; when the thread end is sucked out and the next sewing begins, the second control valve 60 stops working, the negative pressure generator 30 stops working, and the cylinder retracts. When the cylinder retracts to a certain position, the machine starts sewing; after the next sewing is completed, it continues to work according to the above logic.

[0088] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.

[0089] The above provides a detailed introduction to the thread aspirating device and thread aspirating method provided by this application. This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is intended only to facilitate understanding of the solution and core concepts of this application. It should be noted that those skilled in the art may make various improvements and modifications to this application without departing from the principles of this application, and such improvements and modifications are also within the scope of protection of this application.

Claims

1. A thread suction device, characterized in that: include: Suction tube, used to suck up the remaining upper thread; a pneumatic driving member connected to the material suction pipe and used to drive the material suction pipe to move in a direction close to or away from the residual position of the upper thread; a negative pressure generator, connected to the suction pipe, for generating negative pressure so that the suction pipe can suck up the upper thread at the remaining position of the upper thread; The air source component is connected to the air pressure driving component and the negative pressure generator through pipelines respectively, and is used to provide air source to the air pressure driving component and the negative pressure generator to control the operation of the air pressure driving component and the negative pressure generator.

2. The thread aspirating device according to claim 1, wherein: The thread suction device also includes: a first control valve, provided on the pipeline between the air source assembly and the pneumatic drive element, for controlling the on-off of the pipeline between the air source assembly and the pneumatic drive element; a second control valve, provided on the pipeline between the gas source assembly and the negative pressure generator, for controlling the on-off of the pipeline between the gas source assembly and the negative pressure generator; The control module is communicatively connected with the first control valve, the second control valve, the pneumatic drive component and the negative pressure generator, and is used to control the operation of the first control valve, the second control valve, the pneumatic drive component and the negative pressure generator.

3. The thread aspirating device according to claim 2, wherein: A pressure sensor is provided at the negative pressure output end of the negative pressure generator, and the pressure sensor is used to detect the negative pressure value in the suction pipe and transmit the detection signal to the control module.

4. The thread aspirating device according to claim 1, wherein: The pneumatic drive component is a telescopic drive assembly, which includes a cylinder and a telescopic rod. The telescopic rod is connected to the suction pipe to drive the suction pipe to switch between an extended state and a retracted state.

5. The thread aspirating device according to claim 4, wherein: The thread suction device also includes: A fixed sleeve connecting the telescopic rod and the suction pipe; The guide sleeve has a guide hole, and the guide hole is matched with the suction pipe to guide the movement of the suction pipe.

6. The thread aspirating device according to claim 5, wherein: The suction pipe comprises: a bent pipe section, including a retractable flexible pipe section, connected to the negative pressure generator; a straight pipe section connected to the bent pipe section and slidingly engaged with the guide sleeve; and / or The bendable corrugated pipe section is arranged at one end of the straight pipe section away from the bent pipe section and is used to adapt to the curved surface structure of the middle presser foot.

7. The thread aspirating device according to claim 1, wherein: An elastic reset member is provided between the pneumatic driving member and the suction pipe, and the elastic reset member is used to provide an elastic reset force to the suction pipe when the pneumatic driving member stops working, so that the suction pipe has a tendency to switch from an extended state to a retracted state.

8. The thread aspirating device according to any one of claims 1 to 7, characterized in that: The thread suction device further includes a detection module, which is arranged on the material suction pipe and is used to detect whether the upper thread is completely sucked.

9. The thread aspirating device according to any one of claims 1 to 7, characterized in that: The inner wall of the suction pipe is provided with a spiral guide groove, and the spiral guide groove is used to guide the surface thread to smoothly enter the suction pipe.

10. A thread suction method, characterized in that: Applicable to the thread aspirating device according to any one of claims 1 to 9, the thread aspirating method comprising: After receiving a signal indicating that sewing is completed, the air source is provided to the pneumatic driving member through the air source assembly, so that the pneumatic driving member drives the nozzle of the material suction pipe to approach the remaining position of the upper thread; The air source assembly is used to supply an air source to the negative pressure generator, so that the negative pressure generator generates negative pressure and then sucks the noodle thread at the remaining position through the suction pipe; After receiving the sewing start signal, the air source is provided to the pneumatic driving member through the air source assembly, so that the pneumatic driving member drives the pipe opening of the suction pipe away from the upper thread residual position.

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