At present, advanced die cutting machines and hot stamping machines are becoming more intelligent. Multifunctional, large format, high speed, high precision, high stability and online development. Domestic flat-press die-cutting machines are quite close to the world advanced level in some aspects, but there is still a certain gap in speed and accuracy, especially in machine stability and reliability. In the technical indicators of the automatic die-cutting machine, the speed and accuracy of the die-cutting machine are important technical indicators. The speed directly reflects the production efficiency, and the accuracy marks the product quality. Increasing the speed while increasing the accuracy is a difficult problem for the post-press packaging equipment. The following is a further discussion of flat-pressing automatic die-cutting machines, for reference only to the peers.
Accurate positioning of speed feed paper
The automatic paper feeder can be divided into three types according to the way the paper runs: intermittent, continuous, and variable-speed feeding. At present, the continuous paper feeding method is widely used at home and abroad, that is, the front sheet paper and the back sheet paper are always overlapped together. In this way, the paper feeding is stable and the speed is high. At the same die-cutting speed, assuming that the paper has the same settling time at the front gauge, the intermittent feeding speed is much faster than the continuous feeding speed. The speed of paper feeding is faster, and the paper will have a greater impact on the forward gauge, which will easily cause the paper to bounce or curl, resulting in inaccurate positioning and reduced accuracy. In the case of equal feeding speeds, the positioning time of the intermittent feeding is much less than that of the continuous feeding, and the problem of unsteady positioning of the paper in the front gauge and the side gauge occurs, which also causes a decrease in accuracy. If enough paper stability is required for batch feed, the speed of the machine must be reduced to reduce the die cutting capacity. Therefore, intermittent feeding is generally only used for small size and low speed machines, while continuous feeding is mostly used for large format and high speed machines.
In recent years, the use of variable-speed paper feeding has begun on high-speed die-cutting machines. The working principle of variable-speed feeding and continuous feeding is basically the same, but based on this, a paper-transmission mechanism is added. If the average speed of the paper is equal, the positioning time of the variable speed feed and the continuous feed is the same, but the speed change of the feed paper changes at each feed step. When the paper arrives at the front gauge, the paper feeding speed reaches a minimum, the impact of the paper is small, and the positioning is accurate, which helps to improve the cutting speed and precision.
Influence of Body Parts on Speed ​​and Accuracy
The accuracy of the product lies mainly in the die-cutting part of the automatic die-cutting machine, and the parts of the assembly play a key role here. Before the paper enters the gripper row, the body part accurately positions it so that during the die-cutting process, the incision and the indentation line are in the same position on each sheet, achieving the requirements of high die-cutting precision. The positioning of the paper on the regular parts requires that the front, back, and left and right directions be accurately positioned, which is guaranteed by the front gauge and the side gauge, respectively.
After positioning, the paper must also have a high-precision paper transfer mechanism, that is, the paper gripper row body accurately conveys the paper to the die-cut indentation plate for die cutting. In order to ensure the precision of die-cutting, it is necessary to ensure the precision of the transmission and ensure that each row of teeth stays in the correct position. The accuracy and stability of the stopping mechanism of the dental unit plays an important role in the precision of die cutting, and its movement, rest time and stability are determined by the intermittent mechanism of the die cutting machine.
Intermittent mechanism pair
The impact of speed and accuracy
The flat press die cutting machine generally adopts a parallel indexing cam mechanism, which is a conjugate cam mechanism. Compared with intermittent gears such as sheaves and incomplete gears, it has good motion characteristics, smooth start and stop, and the like. Vibration and noise, compact structure. Convenient processing, etc., so it is widely used. When the machine speed is high, the cam profile is affected by the speed, acceleration, inertia size, and direction of the follower, causing the mechanism to vibrate, thus making the feed bar row unstable. Therefore, based on the kinematics principle design, mechanical dynamics is needed to dynamically design the cam profile to ensure that the intermittent mechanism itself is stable. If the intermittent mechanism itself is not stable, the transition to the chain, coupled with the rapid start and stop caused by the tooth row body jitter, resulting in the machine's speed is not high, the accuracy is also greatly affected. In addition, the law of motion of the intermittent mechanism is also very important. After the sine curve is improved, the speed at start and stop is low and the motion is relatively stable.
The motion angle of the intermittent mechanism also has a great influence on the speed and accuracy. The larger the stroke angle, the smoother the machine and the faster the machine speed. Assuming that the die cutting speed does not change, the longer the intermittent mechanism movement time (the larger the moving angle) and the longer the gripper row movement time, the lower the average speed of the row of teeth and the smoother the movement, which is more conducive to improving the accuracy.
Although the positioning mechanism of the die-cutting machine produced by each company is different, the basic principle is the same.
Die cutting precision is divided into two aspects of side accuracy and front accuracy. The gripper tooth row mechanism is composed of a tooth row body and a connecting chain mechanism, and the gripper tooth row structure is reasonable and high in precision, which is very important for die cutting accuracy. In order to eliminate the errors in the length direction of the teeth row, the positioning mechanism on the side of the teeth row generally uses one side for fixed positioning and one side for active positioning. In order to improve the side accuracy, the fixed positioning side of the tooth row should be close to the fixed side positioning plate, so that there is no gap under the action of the positioning spring on the movable side. Assume that the side pull gauge is working without error, the fixed side is positioned with the paper margin on the pull gauge side as a fixed value, and the row length error has no effect on the side accuracy. On the other hand, if the pressure of the movable side positioning spring is insufficient or other factors make the tooth row close to the fixed side positioning plate and there is a gap between the positioning plate, then to solve the side accuracy problem, in addition to improving the accuracy of the side scale, it must be eliminated. Fixed tooth positioning gap error.
In addition, the pull position of the side pull gauge, that is, the distance from the front gauge edge, also affects the accuracy of the side. Automatic die-cutting machine pull gauge distance from the front gauge If you have the same position as the offset gauge of the supporting offset press, you can basically eliminate the paper edge tilt error.
There are many factors affecting the accuracy of the product: 1 The work stability of the intermittent mechanism, especially the start-up and stop of the intermittent mechanism, directly affects the stability of the stalling state of the tooth row, which affects the accuracy of the front. If the intermittent mechanism wears, it will also cause the teeth to fluctuate during stop or start-up, thus affecting the precision before die cutting.
(2) After a long period of operation, the front baffle body determines the change in the front and rear position of the paper, which affects the accuracy of the front.
3 The front and rear positioning blocks that play a role in positioning the grippers should have good strength and stability in order to ensure that each row of teeth is positioned in the same front and rear positioning points.
4 The error of the length of the row of teeth and the lengthening and elongation of the chain will affect the position of the tooth positioning point, which will affect the accuracy of the front. Yuyin's products are imported from Germany, such as MY1050A, MY1060 die-cutting machine designed with a unique mechanism to eliminate the chain length error, which will help improve die-cutting accuracy. The teeth are positioned in the same front and rear anchor points.
4 The error of the length of the row of teeth and the lengthening and elongation of the chain will affect the position of the tooth positioning point, which will affect the accuracy of the front. Yuyin's products are imported from Germany, such as MY1050A, MY1060 die-cutting machine designed with a unique mechanism to eliminate the chain length error, which will help improve die-cutting accuracy.
Accurate positioning of speed feed paper
The automatic paper feeder can be divided into three types according to the way the paper runs: intermittent, continuous, and variable-speed feeding. At present, the continuous paper feeding method is widely used at home and abroad, that is, the front sheet paper and the back sheet paper are always overlapped together. In this way, the paper feeding is stable and the speed is high. At the same die-cutting speed, assuming that the paper has the same settling time at the front gauge, the intermittent feeding speed is much faster than the continuous feeding speed. The speed of paper feeding is faster, and the paper will have a greater impact on the forward gauge, which will easily cause the paper to bounce or curl, resulting in inaccurate positioning and reduced accuracy. In the case of equal feeding speeds, the positioning time of the intermittent feeding is much less than that of the continuous feeding, and the problem of unsteady positioning of the paper in the front gauge and the side gauge occurs, which also causes a decrease in accuracy. If enough paper stability is required for batch feed, the speed of the machine must be reduced to reduce the die cutting capacity. Therefore, intermittent feeding is generally only used for small size and low speed machines, while continuous feeding is mostly used for large format and high speed machines.
In recent years, the use of variable-speed paper feeding has begun on high-speed die-cutting machines. The working principle of variable-speed feeding and continuous feeding is basically the same, but based on this, a paper-transmission mechanism is added. If the average speed of the paper is equal, the positioning time of the variable speed feed and the continuous feed is the same, but the speed change of the feed paper changes at each feed step. When the paper arrives at the front gauge, the paper feeding speed reaches a minimum, the impact of the paper is small, and the positioning is accurate, which helps to improve the cutting speed and precision.
Influence of Body Parts on Speed ​​and Accuracy
The accuracy of the product lies mainly in the die-cutting part of the automatic die-cutting machine, and the parts of the assembly play a key role here. Before the paper enters the gripper row, the body part accurately positions it so that during the die-cutting process, the incision and the indentation line are in the same position on each sheet, achieving the requirements of high die-cutting precision. The positioning of the paper on the regular parts requires that the front, back, and left and right directions be accurately positioned, which is guaranteed by the front gauge and the side gauge, respectively.
After positioning, the paper must also have a high-precision paper transfer mechanism, that is, the paper gripper row body accurately conveys the paper to the die-cut indentation plate for die cutting. In order to ensure the precision of die-cutting, it is necessary to ensure the precision of the transmission and ensure that each row of teeth stays in the correct position. The accuracy and stability of the stopping mechanism of the dental unit plays an important role in the precision of die cutting, and its movement, rest time and stability are determined by the intermittent mechanism of the die cutting machine.
Intermittent mechanism pair
The impact of speed and accuracy
The flat press die cutting machine generally adopts a parallel indexing cam mechanism, which is a conjugate cam mechanism. Compared with intermittent gears such as sheaves and incomplete gears, it has good motion characteristics, smooth start and stop, and the like. Vibration and noise, compact structure. Convenient processing, etc., so it is widely used. When the machine speed is high, the cam profile is affected by the speed, acceleration, inertia size, and direction of the follower, causing the mechanism to vibrate, thus making the feed bar row unstable. Therefore, based on the kinematics principle design, mechanical dynamics is needed to dynamically design the cam profile to ensure that the intermittent mechanism itself is stable. If the intermittent mechanism itself is not stable, the transition to the chain, coupled with the rapid start and stop caused by the tooth row body jitter, resulting in the machine's speed is not high, the accuracy is also greatly affected. In addition, the law of motion of the intermittent mechanism is also very important. After the sine curve is improved, the speed at start and stop is low and the motion is relatively stable.
The motion angle of the intermittent mechanism also has a great influence on the speed and accuracy. The larger the stroke angle, the smoother the machine and the faster the machine speed. Assuming that the die cutting speed does not change, the longer the intermittent mechanism movement time (the larger the moving angle) and the longer the gripper row movement time, the lower the average speed of the row of teeth and the smoother the movement, which is more conducive to improving the accuracy.
Although the positioning mechanism of the die-cutting machine produced by each company is different, the basic principle is the same.
Die cutting precision is divided into two aspects of side accuracy and front accuracy. The gripper tooth row mechanism is composed of a tooth row body and a connecting chain mechanism, and the gripper tooth row structure is reasonable and high in precision, which is very important for die cutting accuracy. In order to eliminate the errors in the length direction of the teeth row, the positioning mechanism on the side of the teeth row generally uses one side for fixed positioning and one side for active positioning. In order to improve the side accuracy, the fixed positioning side of the tooth row should be close to the fixed side positioning plate, so that there is no gap under the action of the positioning spring on the movable side. Assume that the side pull gauge is working without error, the fixed side is positioned with the paper margin on the pull gauge side as a fixed value, and the row length error has no effect on the side accuracy. On the other hand, if the pressure of the movable side positioning spring is insufficient or other factors make the tooth row close to the fixed side positioning plate and there is a gap between the positioning plate, then to solve the side accuracy problem, in addition to improving the accuracy of the side scale, it must be eliminated. Fixed tooth positioning gap error.
In addition, the pull position of the side pull gauge, that is, the distance from the front gauge edge, also affects the accuracy of the side. Automatic die-cutting machine pull gauge distance from the front gauge If you have the same position as the offset gauge of the supporting offset press, you can basically eliminate the paper edge tilt error.
There are many factors affecting the accuracy of the product: 1 The work stability of the intermittent mechanism, especially the start-up and stop of the intermittent mechanism, directly affects the stability of the stalling state of the tooth row, which affects the accuracy of the front. If the intermittent mechanism wears, it will also cause the teeth to fluctuate during stop or start-up, thus affecting the precision before die cutting.
(2) After a long period of operation, the front baffle body determines the change in the front and rear position of the paper, which affects the accuracy of the front.
3 The front and rear positioning blocks that play a role in positioning the grippers should have good strength and stability in order to ensure that each row of teeth is positioned in the same front and rear positioning points.
4 The error of the length of the row of teeth and the lengthening and elongation of the chain will affect the position of the tooth positioning point, which will affect the accuracy of the front. Yuyin's products are imported from Germany, such as MY1050A, MY1060 die-cutting machine designed with a unique mechanism to eliminate the chain length error, which will help improve die-cutting accuracy. The teeth are positioned in the same front and rear anchor points.
4 The error of the length of the row of teeth and the lengthening and elongation of the chain will affect the position of the tooth positioning point, which will affect the accuracy of the front. Yuyin's products are imported from Germany, such as MY1050A, MY1060 die-cutting machine designed with a unique mechanism to eliminate the chain length error, which will help improve die-cutting accuracy.
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