关键词: 多臂开口, 二分法, 共轭凸轮, 综框, 协同, 安全角

Abstract: The rotary electronic dobby has many advantages, such as compact structure, high efficiency, and good stability. In order to control the lifting motion of multi-page healed frames precisely, the current mechanical system of electronic dobby chooses a cam drive in both lifting and selection units. Designing high-precision lifting and selection cams with good dynamic characteristics has always been problematic in developing high-speed electronic dobby. In addition, the motion control of the lifting and selection systems for the heald frame is complementary, so it is necessary to consider the cooperating factors of the lifting and selection process from the process level. This paper combines the composition and operating principle of the rotary electronic dobby and realizes the joint reverse design of the lifting and selecting cams in Matlab software, which is conducive to a deep understanding of the rotary electronic dobby's lifting and selection coordination mechanism. 
By analyzing the process, designing the mechanism, deducing equations, and conducting theoretical calculations, the cycloidal, corrected and constant velocity motion law was applied to the rotation output of the slider rod. A reverse design program for the profile curve of the lifting conjugate cam was developed by Matlab software. The "bisection method" was used to iteratively calculate the coordination parameters of the lifting and selection cams, thereby determining the safety angle of the large disk, the lifting angle, and the return angle of the selection cam. On this basis, combined with the requirements of selection and control, a swinging rod motion law based on a quintic polynomial was constructed, and the theoretical profile curve of the selection conjugate cam was designed and generated through Matlab software. The joint development of the lifting and selection conjugate cams was achieved, and the feasibility of the cooperation between the lifting and selection system was verified. The lifting and selecting cam mechanism has good motion performance and coordination relationship when the motion laws of cycloidal, corrected and constant velocity and the quintic polynomial are employed.
The reverse design ideas and numerical implementation method of lifting and selecting conjugate cams have been clarified, providing an essential reference for designing and developing high-precision rotary electronic dobby.

Key words: electronic dobby, bisection method, conjugate cam, heald frame, collaboration, safe angle