Dynamic Performance Analysis And Research For Cam Pendulum Shear System Of PC Steel Bar

Cam pendulum shearing mechanism is one of key components of the PC steel barshearing equipment, whose work performance can affect the shearing precision andstability of the machine directly. The purpose of this paper is aiming at the shortcomingsof the existing PC shear machine during working, based on the analysis of athleticperformance of the shearing mechanism, exploring the influence of clearance to theworking performance of the cam mechanism, and improving design of cam shearmechanism.Based on the classical Hertz contact theory, contact stiffness of cam high pair isanalyzed in the paper, according to the existing collision contact model of cam motion pair,the model of the conjugate cam motion pair with clearance is established, and checkingformula of cam contact strength is provided. By using the knowledge of rigid bodykinematics and mechanical dynamics, the influence of dynamic performance of shearmechanism with clearance is researched. The reason that caused dynamic impact andvibration of the existing institutions is analyzed in the working process from the twoaspects of static, and indicate the deficiency in design of the existing mechanism.The working characteristic and cutter movement process of the existing shearingmachine are analyzed. Combine with the design method of the existing mechanism,formulate the parameter selection principle of cam mechanism, and build the relativerelationship model of base circle radius, swinging rod length and center distance, the mainparameters of cam mechanism are redesigned, and then a new cam shearing mechanism isdesigned according to the design method. The new cam mechanism made up for theinadequacy of the existing equipment, and effectively improved the working performance.Three-dimensional models with different clearance of the conjugate cam mechanismare simulated by ADAMS, and the curve of the impact force change with clearance isobtained. Combining with cam pair contact stress checking formula, the allowedmaximum scope of clearance in cam pair between swinging rod and cam of the conjugate cam shearing mechanism is obtained. The influence of conjugate cam pair with clearanceto working kinetic characteristic of follower and the overall performance of mechanismare quantitative analyzed.