1. The influence of the processing quality and assembly accuracy of each part
Judging from the single technical parameters of the die cutting machine, the gap between the domestic die cutting machine and the foreign die cutting machine is very small, but there is a large gap in die cutting speed, accuracy, stability, and reliability. Mainly limited by the technical level of the domestic manufacturing industry, many parts are processed rough, the error range is relatively large, and the assembly is not accurate enough, which causes the machine to run fast and the die cutting accuracy is not high enough. For example, the matching and manufacturing accuracy between the intermittent mechanism and the main drive system and chain row directly affect the speed of the machine. If the assembly accuracy is not enough, it will affect the die cutting accuracy and cause noise increase. Another example is the matching of the toggle pressure mechanism and the moving platform. Due to the relative motion, there must be a gap. If the gap is not determined properly, it will cause impact load, vibration, and noise increase, which will affect the speed and accuracy of die cutting.
2. The influence of paper speed and positioning mechanism
At present, the paper feeding method commonly used at home and abroad is continuous paper feeding, that is, a part of the front sheet and the back sheet always overlap together, and this method of sheet feeding is stable and fast. However, the paper feed speed is fast, and the paper will produce a large impact force when it leans against the forward gauge, which may easily cause the paper to curl or bounce, resulting in inaccurate positioning and reduced accuracy. Therefore, the ideal die-cutting machine should ensure the speed of the die-cutting while reducing the speed of the paper on the conveying Table, thereby reducing the impact of the paper on the front gauge, ensuring accurate positioning, and improving the accuracy of the die-cutting.
The printed matter is positioned by the positioning mechanism before die cutting. The positioning mechanism of the die-cutting machine consists of a front gauge, a side gauge, a front gauge mechanism and a rear gauge mechanism. The positioning mechanism has a crucial influence on the accuracy of the die cutting machine.
Before the paper enters the gripper row, it is positioned by the front and side rules. The role of the front rule is to position the paper longitudinally. If multiple front rules are installed, there are only two positioning rules, and the remaining front rules It must be precisely on the same horizontal line to play an auxiliary role, otherwise, it will cause over-positioning and reduce positioning accuracy. The height of the front gauge is adjustable, and the height should be moderate during die cutting and positioning. If the front gauge is adjusted too high, it will cause the front edge of the paper to bend, which will affect the positioning accuracy. No positioning effect. Side gauges are used for horizontal positioning of paper. There are usually two side gauges, but only one is used during work. In order to ensure accurate positioning, the pressure of the side gauge pull roller should be appropriate. Excessive pressure of the paper pulling wheel will cause the side edges of the paper to bend; too little pressure may cause the paper to not be pulled in place, affecting positioning accuracy. In addition, because the positioning time is fixed, the length of the positioning time of the front and side gauges will also affect the positioning accuracy and thus the die-cutting accuracy. Therefore, the positioning time of the front and side gauges should be reasonably allocated.
After the paper is positioned, the paper feed row transfers the paper to the molded part for die cutting and indentation. The paper feed row is fixed on the intermittent conveyor chain. In order to ensure the accuracy of die cutting, it must stay in an accurate position. Therefore, when the paper feed row moves to the end of the cardboard, the front row of gauges drives the row shaft to a certain position to complete the front positioning of the paper feed row. When the conveying chain discharges the paper feeding teeth between the upper platform and the lower platform of the molded part, the rear regulating mechanism moves the shaft of the tooth row to the positioning point to achieve accurate positioning. Therefore, the front and rear gauge mechanisms directly affect the die cutting accuracy.
3. The influence of intermittent mechanism, chain and paper feeding row
The movement of the paper feed row is an intermittent movement process, controlled by the intermittent mechanism. The intermittent mechanism of flat die cutting machine generally uses parallel indexing cam mechanism. Compared with other intermittent mechanisms, it has the following characteristics: reliable movement; smooth transmission; the law of motion of the follower depends on the contour shape of the cam; the turntable can achieve ideal expectations Movement and obtain good power performance, the positioning of the turntable in the intermittent period is completed by the curved groove of the cam, and no additional positioning device is required. When the machine is running at high speed, the cam profile is affected by the speed, acceleration, inertia size and direction of the follower, causing the machine to vibrate. This vibration is transmitted to the chain, and the rapid start and stop will cause the jitter of the paper feed row. , Thereby affecting the speed and accuracy of the whole machine.
Therefore, on the basis of analyzing with dynamics, it is also necessary to dynamically design the cam profile to ensure the smooth movement of the intermittent mechanism itself.
The chain is a flexible piece, and the links are connected with pins, so the pitch error is large. Long-term use, due to wear, will naturally extend the chain and increase the error, which will bring unstable factors to the transmission, affect the position of the positioning point of the feeder row, and thus affect the die cutting accuracy. When working, the chain should not be too tight or too loose. If the chain is too tight, the wear will be accelerated and the service life of the chain will be shortened. If the chain is too loose, the vibration will be severe and the noise will increase.
The paper feed row is used to transport paper. The flat die cutting machine mostly uses solid row, which is easily deformed during the high-speed operation of the machine, which affects the positioning accuracy. Due to its large quality, it is in the process of rapid rotation and instantaneous stop , It will not be easy to stop due to large inertia, affecting machine operation stability and die cutting accuracy. Therefore, it is the direction of future development to change the solid tooth row to a hollow row with higher hardness. In addition, the gripper will produce noise when working, causing vibration of the tooth row, which will affect the die cutting speed, and will also affect other components. Generally, the following measures can be taken: (1) The gap between the plugs is as small as possible; (2) The gripper should be staggered from the rule plate; (3) The gripper angle should be adjusted appropriately. In addition, the pressure of the grippers will also affect the accuracy of the die cutting. Excessive pressure of the grippers will damage the paper; too low pressure will cause the paper to slip or slip off during the transfer process; the pressure between the grippers is not All may cause the paper to skew during die cutting.
Desk For Study , Study Desk For Students , Desk Study Grey ,Table Lamp For Study Desk ,Plastic Study Desk ,Children Desk Study Table
Shenzhen Guang Disen Furniture co.,ltd , https://www.gdisenfurniture.com