A kind of control method and structure of overlock thread trimming

Abstract

The invention provides an overseam trimming control method. The method comprises the following steps that S1, a first sensor and a second sensor are arranged; S2, a standard trimming time T is presetin an electrical control module; S3, when an overseam machine conducts sewing for the M th time, the electrical control module obtains M th current sewing parameters of the overseam machine when edgesof sewing materials pass through the first sensor and the second sensor; S4, when the overseam machine conducts (M+1) th sewing and the first sensor detects passing of the edges of the sewing materials, the electrical control module starts timekeeping, obtains (M+1) th current sewing parameters of the overseam machine at the moment, and is combined with M th current sewing parameters to calculatethe cutting compensation time delta T of the overseam machine during (M+1) th sewing, and the actual trimming time X during (M+1) th sewing in real time, wherein X=T-delta T; when counting of the electrical control module reaches the actual trimming time X, a trimming assembly is controlled to execute trimming motions. The timeliness and accuracy of trimming are guaranteed, and the short thread residue effect with low cost is effectively achieved.

Description

technical field [0001] The invention relates to a control method for overlock thread trimming. [0002] The present invention also relates to an overlock thread trimming control structure for realizing the above overlock thread trimming control method. Background technique [0003] At present, when the overlock sewing machine sews the sewing material, a front braid will be formed at the front edge of the sewing material, and a rear thread braid will be formed at the rear edge of the sewing material, which requires the overlock sewing machine to trim the front braid and Trim short braids at the end of sewing to improve sewing quality. The thread trimming mechanism used to trim the front braid and the rear braid in the existing computerized overlock sewing machine is divided into two types: side suction thread trimmer and machete trimmer, such as the one disclosed in the Chinese utility model patent specification with application number 201521073051.3 Knife set for computeri...

AI Technical Summary

Problems solved by technology

The machete thread trimming needs to be equipped with a sensor. After the sewing material passes the position of the sensor, the electronic control timing of the overlock sewing machine reaches the preset time T and then controls the thread trimming drive source (such as an electromagnet or cylinder) to move to realize thread trimming; The structure of this kind of machete thread trimming can realize low cost, but it also has the following problems at the same time: it is affected by aspects such as the rotational speed of the motor during actual sewing, the sewing needle pitch, and the artificial operation gesture of the worker, so that the required thread trimming time is different from the preset time. If the setting time T is advanced or delayed, it will easily lead to unstable thread trimming length, and it is impossible to achieve the effect of low-cost short thread ends

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