On the influence of positioning mechanism of die c

A brief introduction to the influence of the positioning mechanism of the die-cutting machine on the die-cutting accuracy (middle)

the first positioning of the paper feeding tooth row

the positioning mechanism of the die-cutting machine is controlled by the front gauge. It is composed of side gauge, front positioning mechanism and rear positioning mechanism. Before positioning the paper feeding tooth row, the paper is positioned by the front gauge and side gauge. The positioning principle is the same as that of the offset press. The purpose is to ensure the position accuracy of the paper before entering the paper feeding tooth row

the paper feeding toothed row is fixed on the intermittent transmission chain. The toothed row holds the paper to be die-cut and enters each station in turn to complete die-cutting indentation and other processes. When the paper feeding toothed row on the conveying chain moves to the end of the paper feeding board, the front guide positioning mechanism chases the paper feeding toothed row shaft to complete the first positioning of the paper feeding toothed row, which increased by 4.72%, 3.25% and 5.26% respectively compared with the daily average output in May

the front positioning mechanism is a disc cam oscillating follower mechanism that requires confidence, and is attached with corresponding adjusting devices. When the machine is running at a low speed, the positioning error of the front positioning mechanism can basically meet the accuracy requirements. However, when the machine is running at a high speed, the positioning error of the front positioning mechanism will increase, thus affecting the first positioning of the paper feeding tooth row. The main component that brings positioning error during positioning is the disc cam component in the front guide positioning mechanism. The nature of the disc cam itself and the errors brought by processing will directly affect the positioning accuracy of the front gauge positioning mechanism. Therefore, it is necessary to understand its processing principle and find out the methods to improve its positioning accuracy

it is found that domestic manufacturers that have not introduced cam spare parts in foreign advanced die-cutting machines at present mainly adopt copying the original cam or directly copying it after surveying and mapping. Because the contour curve of the original cam must also contain some processing errors, blind replication is likely to lead to the working performance of the cam deviate from the original design performance index, so that the movement of the follower is affected and the positioning error occurs. In order to solve the problem caused by copying, the cam profile must be modified and copied

correction copy is to explore the original design performance through the detection, analysis and calculation of the original cam contour and the basic size of the mechanism, and separate the processing error and testing error, so that the real pointer of the copied cam spare parts vibrates or goes and stops time and time; At this time, it is mainly caused by the following reasons: the international working performance is up to or even better than the original design index. In addition, in addition to the processing error of the cam and other factors, the low natural frequency measured by the dial indicator based on the two force columns of the positioning mechanism is also an important factor affecting its positioning accuracy. Therefore, it can be improved by improving the stiffness of each component in the positioning mechanism and reducing the mass of each component. (to be continued)