Thread-tension adjusting device of sewing machine

Abstract

Thread adjusting device improves stability and reproducibility in sewing quality by uniforming the texture of stitches obtained at each sewing machine. A cycle sewing machine main body 2 is controlled by a controller 8, and provided with an EEPROM 60 which stores and holds a correction value [Delta]I intrinsic to the sewing machine main body. The controller 8 calculates a level I corresponding to a thread tension value which is set in an operation panel 5, reads the correction value [Delta]I from the EEPROM 60, and allows a driving current with a level (I+[Delta]I) which is obtained by adding the correction value [Delta]I to the level I to flow in an upper thread solenoid 15. The correction value [Delta]I intrinsic to the sewing machine main body is stored and held in the EEPROM 60 of the cycle sewing machine main body 2, so that the driving current with the level (I+[Delta]I) is permitted to flow regardless of the combination of the cycle sewing machine main body 2 with the controller 8.

Description

technical field [0001] The present invention relates to a thread tension adjusting device of a sewing machine which can change thread tension by electric control. Background technique [0002] Conventionally, a sewing machine equipped with a thread tension adjusting device capable of changing thread tension by electrical control is known, for example, as disclosed in Japanese Patent Application Laid-Open No. 2000-202183, and a solenoid applied to a thread gripper is known. Thrust thread tension adjuster. As this solenoid, a solenoid having a thrust force acting on the thread gripper from the movable part of the solenoid and a specific stroke section not following the stroke of the movable part is used. At this time, if the current flowing into the solenoid If it is certain, the thread tension that the thread tensioner acts on the thread varies with the thickness of the thread. Therefore, if you control the current flowing into the solenoid, you can theoretically control th...

AI Technical Summary

Problems solved by technology

[0003] However, in the above-mentioned thread tension adjusting devices, the surface roughness of the thread tensioner and the thread friction surface of each thread tension adjusting device is different due to the deviation of the parts in the manufacturing stage, or the surface finish of each thread tension adjusting device is different. The characteristics of the solenoids on the adjustment devices are different, or the installation condition of the tensioner on each thread tension adjustment device is different, so even if the current levels flowing through the solenoids of each thread tension adjustment device are equal, the The tension actually acting on the thread sometimes varies depending on the thread tension adjustment device

[0004] On the other hand, when the thread tension of the same value is set from the operation panel of each sewing machine, the calculation of converting the thread tension into current by the control device of each sewing machine is the same, and since the same current flows through the solenoid , the tension applied to the thread by each thread tension adjustment device is also different, so there is a problem of non-commutability of setting data between various sewing machines

That is, even if the same value of thread tension is set from the operation panel, and the control device flows a current corresponding to the set value to the solenoid, the tension generated by the thread tension adjusting device on the thread is different for each sewing machine. , and there is a problem that the touch feeling of the stitches formed on each sewing machine is also different

Images