The invention belongs to the technical field of
spinning, and relates to a drafting device for improving the dry uniformity of vortex
spinning lines. The vortex
spinning front drafting area comprises a front roller, a front pressing roller, a middle roller, a middle pressing roller, an upper pin, two symmetrical upper rubber rings, a lower pin, two symmetrical lower rubber rings, a small pressing roller, a transmission
assembly and a lifting mechanism. The small compression roller is parallel to the middle compression roller, penetrates through the two upper rubber rings at the same time and makes contact with the upper surfaces of the working edges of the two upper rubber rings, the distance between the contact point and the jaw of the front roller is D1, the length of the spun
fiber raw material is L, and the absolute value of the difference value between D1 and L does not exceed 3 mm; the transmission
assembly is used for driving the small compression roller to operate along with the middle roller in the same direction and at the same speed so as to apply acting force F1 parallel to the operation advancing direction of the working edges of the upper rubber rings to the two upper rubber rings; and the lifting mechanism is used for adjusting the height of the small compression roller so as to apply a vertically downward acting force FN to the two upper rubber rings. The drafting device is simple in structure, and the air vortex spinning line evenness can be effectively improved.