Three Ways To Improve The Quality Control Of Warp Knitting Machine

In this issue, we selected Chen Chen, Jinjiang, Fujian. warp knitting The experience gained by the limited companies and other units in improving the above problems is hoped that it can be used for reference and reference to enterprises with similar difficulties.

Method one transform counter.

Accurate control of warping time

Li Zhixin, Jinjiang Jing BA (China) Warp Knitting Co., Ltd.

At present, many domestic enterprises are still using mechanical let off mechanism. Warp knitting machine The mechanism has no warp shaft self stopping device and warp yarn allowance rotary display function. Although some domestic enterprises have imported warp knitting machines with EBA let off mechanism and warp shaft self stopping device, due to various reasons, problems such as low accuracy, large error and unfavorable production control are often encountered in actual production. In order to improve efficiency, reduce cost and accurately control the time of warping machine, we have reconstructed the counter of this warp knitting machine.

In the process of transformation, the sensor is preferably installed in a place that can accurately record the rotation data of the warp axis and is relatively hidden, so that the sensor can be prevented from changing the warp shaft or other operations. When installing, considering that both the requirements and the material saving requirements should be met, we think different warp knitting machines with different structures should choose different installation positions. Early production warp knitting machine, because the warp shaft is driven by worm wheel and worm, so the sensor is installed under the shaft head, and a 8 millimeter bolt is installed on the shaft head as the induction point. For warp knitting machine driven by gear belt drive, it is more convenient to install sensors, that is to install a bolt on the gear pulley as an induction point and fix the sensor next to it.

The technology of counting the number of the warp shaft by the counter has the following advantages: high accuracy, simple operation, and solves the problem of poor machine time control. The counter can display the remaining revolutions of the warp shaft in real time, which not only facilitates the arrangement of the next production plan, but also creates conditions for controlling the warp knitting machine's warp knitting machine. The experience of transformation shows that the cost of modification is generally around 300 yuan per axle. We have proved that this method has the advantages of improving feasibility and equipment stability through nearly one year's use.

　 Method two improving comb oscillating mechanism

Further improve the warp knitting machine speed

Cao Qinglin, School of mechanical and automotive engineering, Jiangsu Teachers University of Technology

Warp knitting machine comb through guide needle will yarn The needle moves to the knitting needle. There are usually two kinds of relative motion in the process of yarn laying, one is the movement of the comb, and the needle is not stationary in the process of laying the yarn. This method is called the yarn on which the needle is driven by the comb, and the other is that the comb is stationary, and the needle moves along the trajectory of the needle guiding needle.

When the number of bars is small, the quality and moment of inertia of the comb are small. At this time, the first kind of yarn laying method is generally beneficial to the realization of high speed equipment. This warp knitting machine is usually called high-speed warp knitting machine. When the number of combs is large, the quality of the comb and the moment of inertia are large. The movement of the flower comb is not suitable for the movement along the front and rear directions. The multi bar warp knitting machine usually adopts the passive pad yarn method, that is, the first way of yarn laying. In addition to the up and down movement, the movement of the needle in the first mode is superimposed on the movement of the needle in front of the machine and behind the machine.

It can be seen that in order to further improve the speed of warp knitting machine, we should transform the small comb mechanism. In many cases, the way of reciprocating swing is adopted. The structure is: the comb is fixed on the comb hanger, the hanger is fixed on the pendulum shaft, the pendulum shaft is driven by the comb swing arm to swing back and forth; the multi rod planar linkage mechanism (Qu Bing) is installed on the spindle of the warp knitting machine and driven by the spindle motor, and the active part of Qu Bing is specifically constructed as an eccentric wheel or a crankshaft.

Through the design practice, we can see that the comb movement of the warp knitting machine requires stopping and swaying in the limit position. The WATT type planar six bar linkage with dead point position can be used for a long time. For different types of aircraft, such as the length of the rest time and the size of the swing angle, the user can choose the best solution according to the machine structure layout and transmission angle, or the graphical method can be sorted into analytical expressions, and the optimal solution can be solved by computer program.

　　 Method three change the let off and density values.

Adjusting the thickness of double needle bed warp knitted spacer fabric

Zhou Zhicheng, Chen Zhi Warp Knitting Co., Ltd., Jinjiang, Fujian

With customer pairs of double needle beds interval Textile In order to achieve the same batch of production requirements for different fabric thickness products, the production staff should adjust the gap between the two ring plates. Because of the limitation of machine design, the linkage between the ring plate and the support plate must be adjusted one by one, even adjusting the location of the needle, the depth of the needle, the position and the ratio of the yarn to the warp and so on. When the machine is mobilized several times, it is easy to cause the accumulative error of the connecting rod height. Due to frequent adjustment and variation, the machine will have two twisting and bending, which will cause a cloud like coil defect on the surface of the fabric, and there will be a stab feel on the surface. Therefore, it is necessary to find a more convenient way of production operation.

After practice, we found the following rules: first, we can get different thickness of grey cloth without changing the distance between the needle slot plate and adjusting the amount and density of the comb comb. Second, without changing the distance between the needle plate and the ring, adjusting the amount of the face comb, the amount and density of the hair comb, the gray cloth of different thickness can also be obtained. Third, without changing the distance between the pin and slot, the thickness of the cloth can be obtained by adjusting the amount and density of the face comb, the floor comb and the comb. After adjustment, the thickness of the finished cloth can be reduced by 1.3 millimeters. Fourth, without changing the amount of face comb, floor comb and hair comb, there will be a gap of 0.5 millimeters in the distance between the needle and slot of multiple machines. Only when the density of the machine is changed, can we get a uniform thickness and gram weight grey cloth.

Taking advantage of the above relations, we have chosen a simple and feasible plan that is to keep the distance between the needle and the slot of the machine not fixed, only to change the density value (traction force) and the hair comb amount, so that 2.5 mm ~4.0 mm thick grey cloth can be produced.