Each of the four institutions is to cooperaNeedle rod mechanism, hoisting mechanism, thread lifting mechanism and feeding mechanism are the four main institutions for sewing purposes，it is also the most basic mechanism of all kinds of special sewing machines.Sewing machines, instead of manual sewing, are done through close cooperation between these mechanisms and other related auxiliary parts. For some special machines, different types of machinery are required except for the above-mentioned machinery. In addition, the mechanism of swing needle, cutting knife, cutting wire, opening and stopping mechanism and oil supply and return oil are added.
In order to form a complete line trace, the work of four major mechanisms includes eight stages in the process of forming wire loop, withdrawing needle, entry ring, feeding needle, stitch formation etc. Stitch formation and so on.They te with the associated other bodies in order to complete the sewing needs when a particular task is completed independently.Any organization or associated organization will affect the whole sewing effect if there is bad coordination or failure. Therefore, they are both independent institutions, but must cooperate with each other accurately.
Being familiar with and mastering the operation principle of the four mechanisms is the most basic theoretical knowledge of the maintenance of sewing equipment. It is an important guarantee for good sewing that know about each process well and apply to the processing of equipment failure.
1. Needle bar mechanism
The needle with suture sewing mechanism called puncture needle bar mechanism. The task of the needle bar mechanism is driving machine needle, guide line through the sewing material forming surface of wire ring suture interwoven preparations.
The action of the needle bar mechanism is realized by a machine needle. When the sewing machine is in operation, sewing machines work to stitch the material together, and the needle moves through the hook of the needle.There are vertical, horizontal, straight-line and curvilinear movements of needle stitching materials. The type of needle rod mechanism is different for different purposes of sewing machine. Most sewing machines are in vertical reciprocating linear motion, while some special machines need not only vertical reciprocating straight line motion, but also horizontal swing,such as keyhole machines, nail buckling machines, embroidery machines, etc.But this lateral swing time must occur after the needle leaves the seam material and ends before entering the seam material.
The height position of needle rod is an important parameter in the operation and maintenance of sewing equipment. The height of double straight needle or multiple straight needle is different.As uaual, the long needle shall prevail when the height is positioned.
The distance between the top and the lowest of the needle bar movement is called the needle bar stroke. The needle bar stroke is an important parameter of the sewing equipment, and the stroke of the needle bar and the effective working stroke of the machine needle are different. The effective stroke of the machine needle refers to the distance that the needle reaches the lowest point.
Try to be straight needle selection and seam thickness, seam thickness, quality of sewing technology products to unify, make straight needle sewing in the puncture to ensure that material and sewing thread is not damaged, and is conducive to the formation of the ring line.
1.1 The needle is one of the key parts of the sewing machine, through which every action and mechanism of needle rod mechanism is realized. The needle from the slit to overcome the friction resistance and the forward feed sewing material due to side suture, change the needle and suture material interactions between the three tension reached the highest point.
It is reduce the friction between the needle and seam can take the precise manufacturing of the needle (especially the needle tip), the needle coating and the soft treatment of the sewing material, or the needle , suture and silicone oil.
In addition to the friction between the needle and the stitching, the pressure of the pin and the size of the hole of the needle are influenced by the factors that affect the needle to proceed smoothly.If the needle selection is improper or the manufacturing defect or the hole of the needle plate is too large, a hole is formed on the seam material, so that the damage of the seam material is caused, the aesthetic appearance is influenced, and the firmness is lowered.Therefore, in the case of satisfying the sewing strength requirement, the machine needle with small diameter shall be adopted as far as possible, and special sewing needle shall be selected for special sewing material.
1.2The process of bringing the suture to the back of the seam by the needle is called an incoming line. The phase is from the descent of the needle to the beginning of the contact between the needle eye and the seam material until the desired stitch length is formed.
The length of the thread is not equal to the length of suture needed to form the stitch . It is the important parameter that satisfies the thread loop and can be accurately entered by the thread hook and the thread hook of the sewing machine , so that the thread amount and the actual wire amount are about 6 times in the sewing machine , so that the thread quantity and the actual wire amount are about 6 times in the sewing machine , so that the stitch length can be repeatedly punctured for multiple times , and the friction times are increased , so that the strength of the suture is affected , and the breakage phenomenon can be easily caused.