On the influence of positioning mechanism of die c

2022-08-24
  • Detail

A brief introduction to the influence of the positioning mechanism of the die cutting machine on the die cutting accuracy (Part 2)

the second positioning of the paper feeding tooth row

the second positioning of the paper feeding tooth row occurs before the formal die cutting, and the process is shown in Figure 2. When the conveying chain sends the paper feeding tooth row to the end between the movable platen 1 and the fixed platen 2 of the die cutting indentation part, the paper feeding tooth row on the paper feeding tooth row shaft 3 is chased by the back gauge 4 to complete the second positioning of the paper feeding tooth row

as shown in Figure 3, the rear backup specified position mechanism is composed of rear backup gauge 1 and slot cam 2. The slot cam is fixed on the inner side of the wall panel of the machine operation surface, and the rotating shaft a point of the back gauge is fixed on the f point of the movable plate table 3, which reciprocates up and down with the movable plate table. The roller 4 on the back gauge rolls along the contour surface of the slot cam, and point B is the center of the roller. The rear positioning mechanism is a complex vibration system. The increase of the working speed of the machine will cause the dynamic characteristic deviation of the back gauge when positioning the paper feeding tooth row, which will seriously affect the die cutting accuracy

due to the joint action of the slot cam and the movable plate, the back gauge moves up and down with the movable plate stage on the one hand, and swings with a fixed axis relative to point F on the movable plate stage on the other hand. When the positioning surface of the back gauge is placed perpendicular to the movement direction of the tooth row, the second positioning of the paper feeding tooth row is completed

from the above analysis, it can be seen that the motion of the back gauge is a complex composite motion, which is formed under the joint excitation of the cam contour and the movable platform. Therefore, there are two input sources of the rear positioning mechanism, one is the groove cam profile, and the other is the movable version table. Therefore, we can improve these two parts to optimize the positioning mechanism of the back gauge in order to improve the precision of die cutting. The error of slot cam in the original processing and the error of cam in surveying and mapping form the comprehensive error of cam contour, which causes the positioning error of the back gauge positioning mechanism. Therefore, eliminating this error is conducive to improving the precision and stability of die cutting. In practical analysis, we often use the method of modifying the cam contour to eliminate the comprehensive error of the cam contour

the following briefly introduces two commonly used methods of modifying cam profile

the first method is the comparison method. On the premise of ensuring the motion requirements of the follower, a similar motion law curve is used to replace the motion law of the original follower, and the contour curve of the cam is redesigned

the second method is to deal with and correct the number of follower motion law curve in static analysis and the improvement of element quality, and then correct the contour curve of the cam according to the corrected motion curve. As the movement of the movable plate table also has higher and higher requirements for materials in all walks of life, it is one of the input sources affecting the positioning mechanism of the back gauge, and the motion error of the elbow bar mechanism, the power source of the movable plate table, will also be accumulated, and it will be counted into the positioning error of the back gauge due to the decrease of fuel consumption or the increase of load. Therefore, we should start with optimizing the elbow bar mechanism, further optimize the positioning mechanism of the back gauge, and reduce the positioning error of the back gauge positioning mechanism. Because the prime mover in the elbow mechanism is a crank, the length of the crank can be optimized. 1. The speed regulation system adopts servo electromechanical and reducer hands to minimize the motion error of the elbow mechanism, so as to improve the positioning accuracy of the back gauge positioning mechanism

conclusion

in Fuping die-cutting machine, in addition to the positioning mechanism mentioned above, other mechanisms will also affect the die-cutting accuracy in n direction, so we need to do further research and analysis. Through the above analysis, it is beneficial for us to improve and develop the automatic die-cutting machine for car flattening, so as to design a new type of automatic die-cutting machine with high speed, high precision, high stability and high quality suitable for modern production. (author: Chen Hui, Zhang Haiyan)

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