Automatic thread feeding system of sewing machine and control method thereof

Abstract

The invention discloses an automatic thread feeding system of a sewing machine. The automatic thread feeding system comprises an upper shaft, a lower shaft, a control device, a cloth feeding system and a sewing thread tension adjusting device. One end of the upper shaft is connected with a sewing machine driving mechanism, and the other end of the upper shaft is connected with a thread take-up lever and a sewing needle; one end of the lower shaft is connected with the upper shaft through a transmission shaft, and a rotating shuttle is arranged at the other end of the lower shaft and wound with a sewing bottom thread. The automatic thread feeding system is characterized in that the sewing thread tension adjusting device comprises a rotating body and a stepping motor, the rotating body is connected with an output end of the stepping motor, the sewing machine driving mechanism and a control end of the stepping motor are connected with the control device, the rotating body is wound with a sewing upper thread, and the sewing upper thread penetrates through the thread take-up lever and is connected with the sewing needle. The control method includes the steps of parameter setting, sewing needle sewing, rotating body taking up, cloth moving and rotating body paying off. The sewn stitches are in order, and sewing quality is high.

Description

technical field [0001] The invention relates to a sewing machine, in particular to an automatic thread feeding system of the sewing machine and its control method, which is mainly used for the sewing machine with a thread take-up lever. Background technique [0002] A sewing machine is a machine that uses one or more sewing threads to form one or more stitches on the sewing material to interweave or sew one or more layers of sewing material. The sewing machine can sew fabrics such as cotton, fiber crops, silk, wool, and artificial fibers, and products such as leather, plastics, and paper. [0003] In the prior art, the thread feeding system of the sewing machine with the thread take-up lever is mainly composed of the thread take-up lever, thread gripper and rotary hook. Among them, the thread clamp is completely clamped by manually adjusting the tightness of the spring. However, the thread clamp has the following disadvantages: [0004] 1. The tightness of the thread tensi...

AI Technical Summary

Problems solved by technology

[0004] 1. The tightness of the thread tensioner is adjusted manually. The manual adjustment is not accurate enough, and it is easy to adjust too loose or too tight, which makes the sewing stitches messy;

[0005] 2. When the thread take-up lever rises, when the bottom thread under the fabric is taken away, part of the upper thread will be pulled out from the thread gripper, so the upper thread under the fabric cannot be fully retracted, so that the upper thread under the fabric cannot be tightened , affect the sewing quality of the fabric, and the fabric is easy to take off the thread in the later stage;

[0006] 3. When the thread take-up lever rises and the upper thread is pulled out from the thread clamp, if the thread clamp is adjusted too tightly, it will generate excessive tension on the upper thread. At this time, the upper thread will generate a pulling force on the moving fabric. This pulling force It will affect the flatness of the fabric and affect the entire stitching; if the tensioner is loosely adjusted, it will not be possible to retract all the upper thread under the fabric, so that the upper thread under the fabric cannot be tightened, which will affect the sewing quality of the fabric

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