Thread Trimming Principle Of Computerized Thread Trimming Device For Straight Cylinder Type Stretch Sewing Machine

With the improvement of quality requirements for garment products and the increasing demand for factory production efficiency, more and more factories choose and begin to use computerized sewing machines with automatic functions. The computer thread trimming device of straight cylinder type stretch sewing machine is one of the models that is widely used. This article will Straight cylinder type stretch sewing machine The principle of the computer thread trimming device is introduced, and it is right to throw a brick to attract jade.

The thread trimming principle of the thread trimming device of the tension sewing machine: the needle and thread of the machine are at the upper pole of the thread take-up, that is, the needle bar and the thread take-up bar are at the highest point of the return force, and the thread is in a tightened state. The bobbin thread is at the starting point of the thread take-up cam, that is, at the lowest concave position on the cam, and it lightly touches the bobbin thread at this time. At this time, the feeding of the machine has ended, the stitch of the previous needle has formed, and the stitch has exhausted the amount of thread picked out by the thread take-up cam of the previous needle, so the bobbin thread is also in a tight state.

　　 Thread trimming device The thread trimming mechanism of the thread trimming device starts to move forward to the preset position, and the moving knife of the thread trimming mechanism also extends at the same time. At the beginning of thread trimming, the moving knife hooks the machine line into the fixed knife to cut the line, and then the thread trimming mechanism starts to reset for the next thread trimming. After thread trimming, the needle and thread are cut directly. The bobbin thread is clamped by the fixed knife after being cut to ensure that the first stitch will not jump during the next sewing.

The thread take-up mechanism of the thread trimming device is linked at the same time. The thread pulling mechanism is to leave enough thread ends after thread cutting for the next sewing. The principle is that when the thread trimming mechanism moves forward, the thread take-up mechanism plays the role of thread take-up. At this time, the thread will come out from the thread gripper without loosing the thread. When the thread trimming mechanism reaches the predetermined position, the extended moving knife starts to hook the thread, and the thread take-up mechanism also starts to loosen the thread, because the synchronized thread still maintains a certain tension. When the moving knife returns to the original position, the thread has been cut, and the thread pulling mechanism continues to loosen the thread. This part of thread is the thread head left for the next sewing. Then the thread trimming mechanism starts to reset, the thread release of the thread take-up mechanism ends, and a thread trimming process is completed.

The clearance between the moving knife and the looper hole when it starts to move back can also be understood as the time when the thread take-up mechanism also starts to loosen the thread. To ensure the normal operation of the thread trimming device, Thread trimming principle The timing line at the starting point P is very important for tightening. The needle thread is taken up by the take-up lever, so the adjustment is relatively simple. The bottom thread is a thread take-up cam, and it is required to be clamped to the thread head after thread trimming, so special attention should be paid during adjustment.