Usually there are three types of beating-up mechanism of water jet looms: four-link beating-up, six-link beating-up and conjugate cam beating-up.
1. Link-type beating-up mechanism
For the connecting rod type beating-up mechanism, its kinematic characteristics depend on the length of each rod and the proportional relationship between them, especially the ratio of the crankshaft radius and the length of the hand.
2. Four-bar linkage beating-up mechanism
The advantages of the four-link beating-up mechanism are that the structure is simple, the movement is relatively stable during high-speed operation, and the vibration is relatively low. The disadvantage is that the relative static time is short at the back center, and the flight time of the weft yarn is strictly required, which is not conducive to the high-speed operation of the wide-width loom. The four-link beating-up mechanism used on air-jet looms is mostly in the form of short hand, which is slightly longer in the back center than the middle and long hand four-bar beating mechanism in the back center, which is more conducive to weft insertion. The acceleration is relatively high, which is conducive to beating up.
3. Six-link beating-up mechanism
The six-link beating-up mechanism is equivalent to the series connection of two sets of four-link mechanisms, which can prolong the relative static time of the reed in the rear center, allow the weft to fly more fully, and increase the rotation speed of the wide loom. The advantage of the conjugate cam beating-up mechanism is that the motion law can be designed according to the needs of the weaving process, the back center can have a longer absolute static time, and the weft-insertion time is more sufficient; during beating-up, a higher acceleration can be obtained, and the beating-up force is relatively high. big. The disadvantage is that the machining accuracy is high, the manufacturing difficulty is high, the cost is high; the vibration is large and the energy consumption is high. Under the premise of the same reed width and speed, the energy consumption is about 50% higher than that of the four-bar linkage.
