关键词: 碳纤维, 钢筘, 共轭凸轮, 平行打纬, 共轭间隙, 立体织物, 打纬阻力

Abstract: Multiple weft yarns are arranged in shuttles at different heights during the formation of three-dimensional carbon fiber fabrics. To ensure that each layer of weft yarns can withstand a uniform beating-up force, the reed must move horizontally in the front dead center, simultaneously feeding each layer of weft yarn into the weaving mouth. Traditional beating-up methods, such as linkage and conjugate cam mechanisms, cannot meet the requirements of multi-layer three-dimensional fabric weaving technology because they can only achieve circular arc trajectory movement of the reed. To solve the problem of uniform force on each layer of weft yarns in three-dimensional fabrics, this paper proposed a parallel beating-up mechanism composed of a conjugate cam and a planar linkage.
In this paper, through an analysis of the form and mechanism principle of beating-up, a modified trapezoidal acceleration motion law was applied to the parallel beating-up of a reed. A reverse design program was compiled in the Matlab environment for the swing arm motion law and the conjugate cam theoretical profile. The Step function was used to simulate the beating-up resistance caused by multi-layer three-dimensional fabrics, and a functional prototype simulation model of the parallel beating-up system was constructed by Adams/View software. The kinematic and dynamic performance of the system were simulated and analyzed, taking into account factors such as beating-up resistance, contact collision, and conjugate clearance. A parallel beating-up mechanism suitable for multi-layer three-dimensional fabrics was developed by effectively connecting conjugate cam and planar linkages through mechanism combination. A calculation method and simulation idea for the beating-up resistance of multi-layer three-dimensional fabrics were also proposed. It is found that near the front dead center, the angular acceleration of the rocker shaft reaches its maximum, and the reed undergoes stable horizontal motion along the X direction, which can well meet the requirements of parallel beating-up technology. Due to conjugate clearance, high-frequency collisions between the main and auxiliary cams and rollers can cause mechanical vibration, adversely affecting the dynamic accuracy of parallel beating-up. 
The new beating-up mechanism has good process applicability and practical application prospects. It provides technical ideas for the design innovation of parallel beating-up for multi-layer three-dimensional fabrics made of carbon fibers.

Key words: carbon fiber, reed, conjugate cam, parallel beating-up, conjugate gap, three-dimensional fabric, beating-up resistance