Sewing machine multi-section motor thread trimming control method

Abstract

The invention discloses a sewing machine multi-section motor thread trimming control method, and belongs to the technical field of sewing equipment. The problems that an existing trimmer is unstable in trimming and different in trimmed thread end length are solved. The control method comprises the steps that S1, after thread trimming is started, a thread trimming stepping motor is started to work after a main shaft rotates to reach a knife opening angle alpha, and thread splitting is started at the rotating speed of thread splitting rotating speed V1 till thread splitting is completed; s2, after thread separation is completed, the rotating speed of a thread trimming stepping motor is reduced to a thread protection rotating speed V2 from a thread separation rotating speed V1, a movable cutter of a thread trimming mechanism starts to clamp a bottom thread and an upper thread to a thread groove, and thread protection is completed; and S3, when the main shaft continues to rotate to the angle beta, the rotating speed of the thread trimming stepping motor is switched to the thread breaking rotating speed V3, the movable cutter starts to be driven to be close to the fixed cutter and engaged with the fixed cutter to achieve thread trimming, and thread trimming is completed. The method has the advantage of being good in thread shearing stability.

Description

Technical Field

[0001] The present invention relates to the technical field of sewing equipment, and particularly to a multi-segment motor thread cutting control method for a sewing machine. Background Art

[0002] Both sewing machines and template machines belong to sewing equipment, which are commonly used equipment in the textile industry and are mainly used for processing products such as clothing, shoes and hats. Among them, a sewing machine realizes the connection and fixation of materials by sewing threads on the fabric; while a template machine sews materials according to the shape and position of the mold. Existing sewing machines and template machines usually adopt simple single-segment control of a single motor or mechanical structure for thread cutting. Although this control method is simple, it cannot achieve the stability of thread cutting and the precise control of the length of the cut thread end, and is prone to problems such as failure to cut the thread and uneven lengths of the cut thread ends.

[0003] To solve the above problems, a Chinese patent with the name of a thread cutting control method for a sewing machine and the publication number of CN115897086A is publicly available. The method includes the following steps: S1. An electric control module, a main shaft, an encoder for detecting the angle of the main shaft, and a thread cutting mechanism are provided in the sewing machine; the encoder is communicatively connected to the electric control module, and the angle of the main shaft has an encoder edge zero position uniquely determined according to the output signal of the encoder; the thread cutting mechanism includes a thread cutting motor (10), a thread cutting transmission mechanism, a moving knife (20), and a fixed knife (30), the thread cutting motor (10) is connected to the moving knife (20) through the thread cutting transmission mechanism and drives the moving knife (20) to reciprocate in a direction close to or away from the fixed knife (30), and an avoidance unit is provided in the thread cutting transmission mechanism, and the thread cutting motor (10) is communicatively connected to the electric control module; S2. Determine the needle stop position angle of the main shaft and the thread separating start angle of the main shaft: the needle stop position angle of the main shaft = encoder edge zero position + a first preset angle, the thread separating start angle of the main shaft = encoder edge zero position + a second preset angle, and both the first preset angle and the second preset angle are pre-stored in the electric control module; S3. When sewing is completed, the electric control module receives a thread cutting signal and performs the following control: the main shaft rotates the last circle, when the main shaft rotates through a third preset angle from the needle stop position angle of the last circle, the electric control module controls the motor shaft of the thread cutting motor (10) to rotate in a first direction, and the avoidance unit of the thread cutting mechanism makes there be no power transmission between the thread cutting transmission mechanism and the moving knife (20), and at the same time the sewing machine performs a thread loosening action; the main shaft continues to rotate the last circle, when the main shaft rotates to the thread separating start angle, the avoidance unit of the thread cutting mechanism makes there be power transmission between the thread cutting transmission mechanism and the moving knife (20), and as the motor shaft of the thread cutting motor (10) continues to rotate in the first direction, the thread cutting mechanism sequentially performs a thread separating action and a thread cutting action.

[0004] The above solution preferably solves the problem of instability in thread cutting. However, designing different control methods to solve the problems of unstable thread cutting and uneven lengths of cut thread ends is the direction of efforts of those skilled in the art. Summary of the Invention

[0005] This application provides a multi-stage motor thread cutting control method for a sewing machine, which solves the technical problems of unstable thread cutting and uneven lengths of cut thread ends in the prior art, and achieves the beneficial effects of good stability in thread cutting and precise control of the lengths of cut thread ends.

[0006] This application provides a multi-stage motor thread cutting control method for a sewing machine, which is characterized by including the following steps:

[0007] S1. Thread separation control stage

[0008] After starting thread cutting, wait for the main shaft to rotate to the cutting start angle α, then the thread cutting stepping motor starts to work and starts to move the bobbin thread and the face thread towards the fixed knife at the thread separation speed V 1 to complete thread separation;

[0009] Among them, the cutting start angle α is the deflection angle of the main shaft corresponding to when the moving knife of the thread cutting mechanism starts to move the bobbin thread and the face thread towards the fixed knife for thread separation;

[0010] S2. Thread protection control stage

[0011] After completing thread separation, the speed of the thread cutting stepping motor is reduced from the thread separation speed V 1 to the thread protection speed V 2 , and the moving knife of the thread cutting mechanism starts to move the bobbin thread and the face thread closer to the fixed knife after the above thread separation until the bobbin thread and the face thread are clamped onto the thread groove to complete thread protection;

[0012] S3. Thread cutting control stage

[0013] When the main shaft continues to rotate to the angle β, the speed of the thread cutting stepping motor is switched to the thread breaking speed V 3 and it starts to drive the moving knife closer to the fixed knife and bite with the fixed knife to achieve thread cutting and complete thread cutting;

[0014] Among them, the angle β is the deflection angle of the main shaft corresponding to when the moving knife of the thread cutting mechanism starts to move the bobbin thread and the face thread closer to the fixed knife after thread protection;

[0015] S4. When the main shaft continues to rotate to the angle γ, the main shaft motor stops running, and at the same time the thread cutting stepping motor resets, and the multi-stage motor thread cutting operation is completed;

[0016] Among them, the angle γ is the operating stop angle of the main shaft motor.

[0017] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: during the thread separation in step S2, before the moving knife starts to move the bobbin thread and the upper thread closer to the fixed knife after the above - mentioned thread separation, the thread - loosening electromagnet is controlled to act to loosen the thread; in step S3, before driving the moving knife to approach the fixed knife and engage with the fixed knife to cut the thread, the thread - loosening electromagnet is controlled to close for clamping, and at the same time, the thread - sweeping electromagnet is turned on to sweep the thread.

[0018] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: the thread separation in step S1 is completed when the rotating hook finishes winding to the lowest position or before that.

[0019] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: when the main shaft rotates to the angle β in step S3, the main - shaft thread - lifting lever reaches the highest position.

[0020] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: the thread - separating speed V 1 is 250 revolutions per minute to 350 revolutions per minute. Preferably, it is 300 revolutions per minute.

[0021] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: the thread - hooking speed V 2 is 80 revolutions per minute to 150 revolutions per minute. Preferably, it is 100 revolutions per minute.

[0022] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: the thread - breaking speed V 3 is 40 revolutions per minute to 60 revolutions per minute, and when the thread - cutting stepping motor resets during the thread - cutting process, the thread - cutting stepping motor resets at a reset speed of 150 revolutions per minute to 250 revolutions per minute. Preferably, the thread - breaking speed V 3 is 50 revolutions per minute, and the reset speed is 200 revolutions per minute.

[0023] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: the cutting - knife opening angle α is 290° to 310°. Preferably, it is 304°.

[0024] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: the angle β is 65° to 75°. Preferably, it is 70°.

[0025] In the above - mentioned multi - stage motor thread - cutting control method for a sewing machine, it is characterized in that: the angle γ is 48° to 58°. Preferably, it is 53°.

[0026] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0027] Due to the adoption of a multi - stage motor control method, specifically by adjusting the action timing of the thread - cutting stepping motor in segments according to the different angular positions of the main shaft, and enabling the thread - cutting stepping motor to control the moving knife to accurately control the wire splitting, wire protection, and wire breaking operations according to the mechanical operation trajectory. Therefore, it effectively solves the technical problem in the prior art that the stability of thread cutting is poor and the thread cannot be cut, and further realizes the beneficial effects of good stability in thread cutting and accurate control of the length of the cut thread end. Brief Description of the Drawings

[0028] Figure 1 It is a flow chart of the multi - stage motor thread - cutting control method of this sewing machine.

[0029] Figure 2 It is a working principle flow chart of the multi - stage motor thread - cutting control method of this sewing machine. Detailed Embodiment

[0030] The embodiment of this application provides a multi - stage motor thread - cutting control method for a sewing machine, which solves the technical problems of unstable thread cutting and inconsistent lengths of the cut thread ends in the prior art.

[0031] The technical solution in the embodiment of this application to solve the above problems of unstable thread cutting and inconsistent lengths of the cut thread ends is as follows:

[0032] As Figure 1 shown, it is achieved through the following steps.

[0033] S1. Wire - splitting control stage

[0034] After starting thread cutting, wait for the main shaft to rotate to the knife - opening angle α, then the thread - cutting stepping motor starts to work and starts to move the bobbin thread and the face thread towards the fixed knife at the wire - splitting speed V 1 until the wire splitting is completed.

[0035] Among them, the knife - opening angle α is the deflection angle of the main shaft corresponding to when the moving knife of the thread - cutting mechanism starts to move the bobbin thread and the face thread towards the fixed knife for wire splitting.

[0036] S2. Wire - protecting control stage

[0037] After completing wire splitting, the speed of the thread - cutting stepping motor is reduced from the wire - splitting speed V 1 to the wire - protecting speed V 2 , and the moving knife of the thread - cutting mechanism starts to move the bobbin thread and the face thread closer to the fixed knife after the above - mentioned wire splitting until the bobbin thread and the face thread are clamped onto the wire groove to complete wire protection.

[0038] S3. Thread - cutting control stage

[0039] When the main shaft continues to rotate to the angle β, the speed of the thread - cutting stepping motor is switched to the wire - breaking speed V3 and start driving the moving knife to approach the fixed knife and engage with the fixed knife to cut the thread, completing the thread cutting;

[0040] Among them, the angle β is the deflection angle corresponding to the main shaft when the moving knife of the thread cutting mechanism starts to continue approaching the fixed knife with the bottom thread and the top thread after protecting the thread;

[0041] S4. When the main shaft continues to rotate to reach the angle γ, the main shaft motor stops running, and at the same time, the thread cutting stepping motor resets, and the multi-stage motor thread cutting work is completed;

[0042] Among them, the angle γ is the operating stop angle of the main shaft motor.

[0043] By combining different angular positions of the main shaft to segmentally adjust the action timing of the thread cutting stepping motor, the thread cutting stepping motor controls the moving knife to accurately control the wire splitting, wire protecting, and wire breaking operations according to the mechanical operation trajectory. In the multi-stage motor control mode, the technical problem of poor stability of thread cutting and wire breakage in the prior art is effectively solved.

[0044] To better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0045] Embodiment 1

[0046] A multi-stage motor thread cutting control method for a sewing machine is provided, including the following steps:

[0047] S1. Wire splitting control stage

[0048] After starting the thread cutting, wait for the main shaft to rotate to the knife-opening angle α, the thread cutting stepping motor starts to work and starts to dial the bottom thread and the top thread towards the fixed knife at the wire splitting speed V 1 to perform wire splitting until the wire splitting is completed, and the wire splitting action is completed when the rotary hook finishes winding the thread to the lowest position or before, so as to ensure that the wire splitting action is completed under tension;

[0049] Among them, the knife-opening angle α is the deflection angle corresponding to the main shaft when the moving knife of the thread cutting mechanism starts to dial the bottom thread and the top thread towards the fixed knife for wire splitting. The knife-opening angle α is 290° - 310°. The knife-opening angle α in this embodiment is 304°. The knife-opening angle α is a preset angle obtained according to the mechanical structure, which is the angle at the moment when the bottom and top threads are separated; the preset wire splitting speed V 1 is 250 - 350 revolutions per minute. The wire splitting speed V in this embodiment 1 is specifically 300 revolutions per minute; whether the wire splitting is completed can be judged according to the position of the thread cutting stepping motor, or by the number of steps, preset, or by the stroke, etc.

[0050] S2. Wire protecting control stage

[0051] After the thread splitting is completed, the rotation speed of the thread cutting stepping motor decreases from the thread splitting speed V 1 to the thread protecting speed V 2 . At the same time, the loose thread electromagnet is controlled to act to loosen the thread. The moving knife of the thread cutting mechanism starts to move the bobbin thread and the upper thread closer to the fixed knife in the direction of the fixed knife after the above-mentioned thread splitting until the bobbin thread and the upper thread are clamped onto the thread groove, completing the thread protection;

[0052] Among them, the thread hooking speed V 2 is 80 revolutions per minute to 150 revolutions per minute. The thread hooking speed V of this embodiment 2 is 100 revolutions per minute;

[0053] S3. Thread cutting control stage

[0054] When the main shaft continues to rotate to the angle β, the loose thread electromagnet is controlled to act to close and clamp, and at the same time, the thread sweeping electromagnet is turned on to perform thread sweeping. At this time, the main shaft thread take-up lever reaches the highest position, and the rotation speed of the thread cutting stepping motor switches to the thread breaking speed V 3 and starts to drive the moving knife close to the fixed knife and bite with the fixed knife to achieve thread cutting, completing the thread cutting;

[0055] Among them, the angle β is the deflection angle of the main shaft corresponding to when the moving knife of the thread cutting mechanism starts to move the bobbin thread and the upper thread closer to the fixed knife in the direction of the fixed knife after thread protection; the angle β is 65° to 75°, and the angle β of this embodiment is 70°.

[0056] S4. When the main shaft continues to rotate to the angle γ, the main shaft motor stops running, and at the same time, the thread cutting stepping motor resets, and the multi-stage motor thread cutting work is completed;

[0057] Among them, the angle γ is the running stop angle of the main shaft motor, the angle γ is 48° to 58°, and the angle γ of this embodiment is 53°.

[0058] As Figure 2 shown, the specific control process of this multi-stage motor thread cutting control method for sewing machines is as follows:

[0059] Start thread cutting. After the thread cutting starts, it is detected whether the cutting start angle α of the main shaft has reached 304°. If it has reached, the thread cutting stepping motor starts to work, and then the thread splitting control stage starts. The first-stage thread cutting stepping motor acts to start thread splitting. At this time, the thread splitting speed V 1 is specifically 300 revolutions per minute, and then wait for the stroke action of the thread cutting stepping motor to be completed (that is, the thread splitting action is completed); when the thread splitting action is completed, the thread protecting control stage is started. At this time, the thread hooking speed V 2 is 100 revolutions per minute, that is, the second-stage thread cutting stepping motor acts to start thread protecting. At the same time, the loose thread electromagnet is controlled to act to loosen the thread. When the main shaft rotates to the position of the angle β = 70°, the rotation speed of the thread cutting stepping motor switches to the thread breaking speed V 3, start the wire-breaking control phase, that is, the third-stage wire-cutting stepping motor starts to break the wire. At this time, control the wire-loosening electromagnet to act to close and clamp, and at the same time turn on the wire-sweeping electromagnet to perform wire-sweeping; when the main shaft rotates to the angle γ = 53°, stop, the main shaft motor stops running, and at the same time the wire-cutting stepping motor resets, and the wire-cutting is completed.

[0060] Adopt multi-stage motor control technology, and perform segmented control according to the angular position of the main shaft to ensure that the scissors can accurately divide the bobbin thread and the surface thread to be cut. Specifically, at the moment when the first-stage wire-dividing reaches the main shaft deflection angle of 304°, the wire-cutting stepping motor runs at a high speed of 300 revolutions per minute to quickly open the knife for wire-dividing control. In this stage, the motor runs as fast and stable as possible to ensure that the moving knife can divide the bobbin thread and the surface thread to be cut, and complete the wire-dividing action when the rotary hook completes winding to the lowest position. Second, the wire-cutting stepping motor switches to a slow speed of 100 revolutions per minute and runs the second displacement to stop before wire-breaking. At this time, the moving knife has clamped the wire into the wire groove, and slowing down the speed helps to control wire-cutting and wire-hooking, improving the stability of wire-cutting. Third, the main shaft continues to run to the angle β = 70°. At this time, the main shaft thread take-up lever reaches the highest position (ensuring that the surface thread is the longest at this time), and then control the wire-cutting stepping motor to switch to the wire-breaking speed V 3 And start to drive the moving knife to approach the fixed knife and bite with the fixed knife to achieve wire-cutting and complete the wire-cutting. At this time, turn off the wire-loosening electromagnet, turn on the wire-sweeping control, the main shaft returns to 53°, and the wire-cutting stepping motor resets to complete stable wire-cutting control. Adopt a real-time monitoring and adjustment method to realize real-time monitoring and adjustment of the wire-cutting, wire-dividing, winding and wire-collecting processes, and further improve the wire-cutting accuracy and effect.

[0061] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0062] 1. Precise control: The present invention adopts a multi-stage motor control method, controls the scissors action by programming the wire-cutting stepping motor, and combines with the wire-loosening electromagnet and the wire-sweeping electromagnet for coordinated control. It operates in segments according to the angular position of the main shaft, and controls the wire-cutting stepping motor to run in segments at the set optimal speed, achieving precise control of the operation of the wire-cutting stepping motor. Compared with the single-motor control method in the prior art, the control method of the present invention is more refined, which can effectively avoid problems such as inaccurate cutting caused by unstable running speed or improper control of the wire-cutting stepping motor, and improves the wire-cutting rate and the stability of the wire-cutting thread head length;

[0063] 2. Real-time monitoring and adjustment: The present invention can realize real-time monitoring and adjustment of the wire-cutting process by controlling the wire-cutting stepping motor to run in segments according to the angular position of the main shaft. Compared with the prior art, the control method of the present invention is more flexible and can be adjusted in real time according to the actual situation during the wire-cutting process, further improving the wire-cutting accuracy and effect;

[0064] 3. Improve production efficiency: This segmented control operation mode can effectively improve the stability of wire cutting, thereby improving production efficiency, shortening the production cycle, and reducing production costs;

[0065] 4. Good stability: Compared with the prior art, the control mode of the present invention is more stable, improving the quality of wire cutting.

[0066] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0067] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for controlling thread trimming of a multi-stage motor of a sewing machine, characterized in that: The steps include: S1, line control stage After starting the thread trimming, wait for the main shaft to rotate to the knife angle α, the thread trimming stepper motor starts working and starts to move the bottom thread and the surface thread toward the fixed knife direction at the speed of the thread splitting speed V1 to split the thread until the thread splitting is completed; The knife angle α is the deflection angle of the main axis corresponding to when the moving knife of the thread trimming mechanism starts to move the bottom thread and the surface thread toward the fixed knife direction; S2, line protection control stage After the line division is completed, the speed of the line trimming stepper motor is reduced from the line division speed V1 to the line protection speed V2, and the moving knife of the line trimming mechanism starts to move the bottom thread and the upper thread closer to the fixed knife after the above-mentioned line division until the bottom thread and the upper thread are stuck in the thread groove, thus completing the line protection; S3, thread trimming control stage When the spindle continues to rotate and reaches the angle β, the speed of the thread trimming stepper motor switches to the thread breaking speed V3 and starts to drive the moving knife to approach the fixed knife and engage with the fixed knife to achieve thread trimming, thus completing the thread trimming; The angle β is the deflection angle of the main axis corresponding to when the moving knife of the thread trimming mechanism starts to approach the fixed knife direction with the bottom thread and the top thread after protecting the thread; S4, when the spindle continues to rotate and reaches the angle γ, the spindle motor stops running, and the thread trimming stepping motor is reset at the same time, and the multi-stage motor thread trimming work is completed; Among them, the angle γ is the parking angle of the spindle motor.

2. A sewing machine multi-stage motor thread trimming control method as claimed in claim 1, characterized in that: When the line division is completed in step S2, the line loosening electromagnet is controlled to loosen the line before the movable knife starts to move the bottom line and the top line closer to the fixed knife after the line division; in step S3, before the movable knife is driven close to the fixed knife and engages with the fixed knife to cut the line, the line loosening electromagnet is controlled to close for clamping, and the line sweeping electromagnet is turned on for sweeping.

3. A sewing machine multi-stage motor thread trimming control method as claimed in claim 2, characterized in that: The thread splitting in step S1 is completed when or before the rotary hook completes winding to the lowest position.

4. A sewing machine multi-stage motor thread trimming control method as claimed in claim 3, characterized in that: In step S2, when the main shaft rotates to an angle β, the main shaft thread take-up lever reaches the highest position.

5. A sewing machine multi-stage motor thread trimming control method as claimed in claim 1 or 2 or 3 or 4, characterized in that: The line splitting speed V1 is 250 rpm to 350 rpm.

6. A sewing machine multi-stage motor thread trimming control method as claimed in claim 5, characterized in that: The line hooking speed V2 is 80 rpm to 150 rpm.

7. A sewing machine multi-stage motor thread trimming control method as claimed in claim 6, characterized in that: The thread breaking speed V3 is 40 rpm to 60 rpm, and the thread trimming stepping motor is reset at a reset speed of 150 rpm to 250 rpm.

8. A method for controlling thread trimming of a multi-stage motor of a sewing machine as claimed in claim 1, 2, 3 or 4, characterized in that: The incision angle α is 290° to 310°.

9. A sewing machine multi-stage motor thread trimming control method as claimed in claim 8, characterized in that: The angle β is 65° to 75°.

10. A sewing machine multi-stage motor thread trimming control method as claimed in claim 9, characterized in that: The angle γ is 48° to 58°.

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