High precision thread trimming device and method for embroidery machine

Abstract

The invention discloses a high precision thread trimming device and a high precision thread trimming method for an embroidery machine. The device comprises a plastic cutter driving device and a thread trimming device, wherein the plastic cutter driving device is arranged at the upper side of a faller; the thread trimming device is arranged at the lower side of the faller; the plastic cutter driving device comprises a plastic cutter motor; a position sensor and an eccentric wheel are respectively arranged on the periphery of a drive shaft of the plastic cutter motor; the eccentric wheel is connected with a swing rod with a sliding chute at one end by a pin roller; a stationary shaft connected with a motor base is arranged in the middle of the swing rod; the other end of the swing rod is connected with a pull rod driving a plastic cutter by a connecting rod. The device has the beneficial effects that the exact position of the plastic cutter when going back is determined via the position sensor on the periphery of the drive shaft of the plastic cutter motor, thus achieving high precision control of the thread trimming length and avoiding technical defects caused by main shaft speed fluctuation.

Description

technical field [0001] The invention relates to a thread trimming device and method, in particular to a high-precision thread trimming embroidery machine thread trimming device and method. Background technique [0002] At present, for the embroidery machine industry, after completing one graphic unit of embroidery, it is necessary to trim the upper thread and lower thread under the cloth surface when starting to embroider another graphic unit. Due to the large number of embroidery units, frequent thread trimming is required, and the thread trimming remains The lower thread end is located under the cloth surface, and the length of the thread end is directly related to the quality of the embroidery and the cost of the upper thread. The existing thread trimming method is generally that one upper thread driven by the flower machine needle passes through the cloth surface to form two upper threads. These two upper threads wrap the bottom thread under the cloth surface through the...

AI Technical Summary

Problems solved by technology

The existing thread trimming method is generally that one upper thread driven by the flower machine needle passes through the cloth surface to form two upper threads. These two upper threads wrap the bottom thread under the cloth surface through the rotary hook. Scissors cut a strand of upper thread and lower thread, and the cut strand of upper thread and lower thread forms a thread end under the cloth surface. The scissors have no ability to control the length of the thread end, that is, the thread end will be long and short for a while. The main factor affecting the length of the thread head is the length of the thread trimming caused by the change in the time when the scissors start cutting the thread caused by the fluctuation of the speed of the spindle speed.

[0003] Of course, there are also mechanical structures such as hook knife, upper thread clamping, and thread hook in the existing thread trimming process, but these mechanical structures do not control the length of the thread trimming. The main function of the hook knife is to maintain the tension of the upper thread and to help Although

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