At present, many domestic enterprises are still using mechanical warp knitting machines with warp feeding mechanisms, which do not have self stopping devices for warp knitting machines and display functions for the remaining number of warp yarn revolutions. Although some domestic enterprises have also imported warp knitting machines with EBA warp feeding mechanisms and self stopping devices for warp knitting machines, due to various reasons, problems such as low accuracy, large errors, and unfavorable production control often occur in actual production. In order to improve efficiency, reduce costs, and accurately control the warp knitting machine time, we have modified the counter of this warp knitting machine.
When renovating, sensors should be installed in places that can accurately record the rotation data of the warp axis and are relatively concealed, so as to prevent the sensors from being damaged during the replacement of the warp axis or other operations. When installing, considering the need to meet both usage requirements and material conservation requirements, we believe that different installation positions should be selected for warp knitting machines with different structures. In the early production of warp knitting machines, sensors were installed below the warp shaft head due to the transmission of the warp shaft through worm gears. An 8mm bolt was installed on the shaft head as the sensing point, which could achieve the goal of the sensor acting once for every rotation of the warp shaft. For warp knitting machines driven by gear belts, it is more convenient to install sensors by installing a bolt on the gear belt pulley as the sensing point and fixing the sensor next to it.
This technology, which relies on a counter to record the number of axes and machine conditions, has the following advantages: high accuracy, simple operation, and solves the problem of difficult control of machine time. The counter can display the remaining number of warp threads in real time, which not only facilitates the arrangement of the next production plan, but also creates conditions for controlling the multi warp threads of the warp knitting machine. The experience of renovation shows that the renovation fee is generally around 300 yuan per axle. We have proven through nearly a year of use that this method has the advantages of improving feasibility and equipment stability.
The warp knitting machine comb guides the yarn towards the knitting needle through the guiding needle to achieve the action of padding the yarn. There are generally two forms of relative motion in the process of lining yarn. One is the comb movement, where the knitting needle remains stationary during the lining process. This method is called the comb actively lining the knitting needle; Another method is for the comb to remain stationary while the needle actively moves along the trajectory of the guide needle hole, which is called passive yarn padding by the comb to the needle.
When the number of comb bars is small, the comb bar mass and moment of inertia are both small. At this point, generally adopting the first type of yarn padding method is beneficial for the equipment to achieve high speed, and this type of warp knitting machine is commonly referred to as a high-speed warp knitting machine. When there are many combs, the comb mass and moment of inertia are large, and the transverse movement of the flower comb is not suitable for movement in the front and rear directions of the machine. Multi comb warp knitting machines generally use passive yarn padding method, which is the first type of yarn padding method. At this point, in addition to the up and down movement, the needle movement also superimposes the movement of the comb along the front and back directions of the machine in the first method onto the needle movement.
It can be seen that in order to further improve the speed of the warp knitting machine, the less comb mechanism should be modified. The active yarn padding process of the few comb warp knitting machine comb often adopts a reciprocating swinging motion. Its structure is: the comb is fixedly installed on the comb hanger, and the hanger is fixedly installed on the swing shaft, which is driven by the comb swing arm to achieve reciprocating swinging; The active component (crank) of the multi bar planar linkage mechanism is installed on the spindle of the warp knitting machine and driven by the spindle motor. The specific structure of the active component crank is an eccentric wheel or crankshaft.
Through design practice, it can be seen that the comb motion of a few comb warp knitting machine requires a stop and reciprocating swing at the extreme position. By using a WATT type planar six link mechanism with a dead point position, a longer approximate stop can be achieved. For different machine models, users can choose the optimal solution based on the machine structure layout, transmission angle, and other requirements, as well as organize the graphical method into analytical expressions and solve the optimal solution through computer programs.