The composition structure and characteristics of the drafting machine are introduced

The composition of the draft machine: The draft machine is composed of a draft box, impregnating roll, press roll winding roll automatic stop device, lubricating oil road and compressed air pipeline.

1. Draft box: The draft box is equipped with a draft shaft, transmission gear, and lubricating oil device to lubricate each bearing and gear respectively.

2, draft roller components A stretch machine is generally equipped with five or seven draft rollers. Most of the draft rollers are cantilever type. It is divided into two kinds, one is the draft roll with no heating medium inside, and the other is the draft roll with cooling water inside.

3. Press roller: In order to prevent the tow from slipping on the pull roller, a press roller is often added to the draw roller. Its structure has two forms: self-tightening and loading.

(1) The self-tightening press roller is between the two draft rollers. Form a font. The self-tightening roller has two pressure methods, one is to press the tow by the weight of the press roller, and the other is to press the tow by the pressure of the cylinder in addition to the weight of the press roll.

(2) loaded roller: according to the different positions of the roller and the draft roller can be divided into the upper roller and the lower roller. The upper press roll is above the draft roll, and the total pressure is the sum of the cylinder pressure and the weight of the press roll. Generally used for small draft machines. The lower roll is under the draw roll. Total pressure is the difference between cylinder pressure and roll weight. Generally used for large drawing machines. The lower roll can partially offset the bending deformation of the cantilever end of the draft roll. The roller surface is coated with rubber to increase the coefficient of friction. The pressure is generally pressurized by cylinder or cylinder. It can be pressurized by double cylinder or single cylinder through connecting rod mechanism.

4, dip roll: the last roll of the first draft machine and the first roll of the second draft machine are respectively impregnated rolls, immersed in the water bath, the first draft machine impregnated rolls through the cooling water to control the tensile point of the tow.

5, roll winding automatic stop device: an aluminum plate is placed near the surface of the roll, when the roll winding, the mess will make the aluminum plate transposition, drive the lever to move a pulley transposition, make the detector compressed air to turn, the air transformer sends a signal, make the combined machine stop or reduce to low speed, and issue an alarm.

The essence of the draft is the redistribution of the fiber in the length direction in the direction of the whisk, and the length of the output product can be extended relative to the input product, or it can be shortened. If the process of transferring the fiber to the Doffer is considered as drafting, the drafting is the distribution of the fiber on a shorter segment, similar to the drafting between the comb roller and the spinning cup in spinning cup. The older common form of drafting is roller drafting, which is a process of lengthening and fining a whisker by means of a system of rotating rollers with different surface speeds. In addition, the form of the input product and the output product before and after the draft can be the same or different, such as carding machine, strip winding machine and other coiling forms are different; There are also the same, such as union, coarse, thin.

After the yarn is drawn, the connection between the fibers is weakened, and the ability to withstand the draft in the next draft zone is correspondingly reduced, so too much draft zone may not increase the total draft much. Sometimes a collector is used at the end of a draft zone to make the fibers in the yarn close together and then draw. For example, the drafting of 4 pairs of simple rollers can have three drafting areas. Their draft distribution gradually increases from back to front, which is called continuous draft or incremental draft. If the middle drafting area uses a collector to make the whisker drawn through the back area close together, and the drafting multiple is equal to or close to 1, the drafting mechanism of the 4 pairs of rollers actually uses only two drafting areas, which is called two-zone drafting. Two-zone drafting is characterized by the addition of a collection area in the middle of two draft zones.