General trouble shooting method of needle car

Broken wire is the most common problem of needle car. Generally, it occurs in the first sewing and sewing process, which causes many reasons for thread breakage. It is difficult to describe the matter clearly and to understand the repair method simply by describing in words or by using a diagram or two. Make sure the reason for the disconnection. It is necessary to analyze the specific problems and find out the relationship between needle and thread of sewing machine and which parts and their movement way. All parts of the needle, such as presser foot, needle plate hole, shuttle frame, etc., shall not be abraded, otherwise the thread will be broken. All the places where the line passes, such as shuttle frame, shuttle, shuttle support, etc., must be smooth and undamaged, otherwise the wire will be broken. When the machine breaks the wire, first remove the needle plate, turn the upper wheel slowly by hand, and look down from the top to the bottom, observe the relationship between the line and the parts it passes through, see if there is any phenomenon of wire hanging and scraping, and find out the cause of the disconnection. Determine the repair method.

The broken line is generally divided into two types: dramatic and general. The former is easy to find, while the latter is difficult to find. For example, the sharp break (i.e. the line is cut neatly) is inevitable due to the breakage of the shuttle frame tip.

The break of the shuttle skin is also one of the reasons for the severe breakage of the thread, because each sewing needle must pass through the outer part of the shuttle skin. The shuttle skin is broken, the online movement is blocked, and it must be scraped and broken, causing severe broken line. In case of this phenomenon, only remove the shuttle screw and replace the new shuttle skin.

The loss of elasticity of the shuttlecock cover is also the cause of severe broken line. Every sewing needle, the line must pass through the outside of the shuttle door. The door cover must be opened and the upper thread must be scraped. This is mainly caused by the loss of elasticity of the shuttle door spring. During maintenance, only take the shuttle sleeve out of the shuttle bed, then screw down the shuttle door screw in the shuttle sleeve, take out the full set of shuttle door and replace the shuttle door spring.

In addition, the clearance between the shuttle support and the shuttle frame is too small, and the line can not be put forward smoothly. Also, severe disconnection is required. At this time, only use a wrench to gently pull the shuttle support outward to adjust the gap between the two parts to a standard distance of 0.6-0.8mm. In addition, the needle is installed in reverse. The reason for the sharp wire breaking is that the thread hole of the thread rod is too tight and the groove is worn out.

The reason of common broken line is difficult to check, because its fault is not obvious. It depends on hand touch, observation and correct judgment to find. For example, the surface of the needle plate hole, spindle core sleeve, shuttle frame, shuttle support spring and needle hole is rough or burr. It is most likely to cause common disconnection. Similar faults can be eliminated only by grinding the burr gently with oilstone or fine sand cloth to make the surface of parts smooth. If the needle hole is rough, the machine needle must be replaced.