Discussion on the Adjustment of Transferring Time Between Side Plane and Feeding Handle from Overprint Fault

In the operation of the J2205 offset press, sometimes encountered such a fault: the pull distance of the side gauge is very limited, and usually the paper transported by the feeder, the off-side specified position baffle must be within 4mm to pull in position, if the paper is fed If there is a slight deviation, it is easy to create a phenomenon that it is not pulled or pulled. At the same time, it is also accompanied by a longitudinal overprint failure that is not in place.

At first, it was suspected that there was a problem with the pull gauge. After inspection, there was no abnormality in the pull gauge, and when the empty car was opened, a paper strip was put under the pull roller to pull it. The maximum pull distance can reach 11mm. Excluding the problem of pulling gauges, the following inspections were performed on the paper handing teeth. The distance between the tooth pad and the paper feeding table was appropriate. The force of each tooth was uniform and the movement was consistent. When the car was at 77°, the roller was just opened and closed. The disengagement from the closed tooth bumps corresponds exactly to the pull-up time.

In the end, we put an entire sheet of print on the paper-sheeting station of the delivery station. We slowly re-checked the car and finally found that the paper-feeding tooth was holding the paper ahead of time. After the problem was discovered, we re-adjusted the timing of the transfer between the pull gauge and the delivery tooth. In order to ensure that the paper teeth can be pinched and transported while the pull tab is raised, the paper can be accurately positioned and transported. First, when adjusting the lift time of the pull gauge, point the car to 77° and tear the printed sample into a paper strip. , Put it under the pull roller, and adjust the cam that controls the swing motion of the pull roller so that the pull roller has no pressure on the paper. Then, loosen the fastening screw of the closed tooth bump of the paper feed and turn the position of the bump. The paper strip test conveys the paper to the paper so that the paper hand just holds the paper; finally, the fastening screw of the lug is locked. After repeated adjustments, overprinting of printed products is accurate and the failure is completely eliminated.

After troubleshooting, we analyzed and summarized the problems.

1. It is the key to guarantee the accuracy of overprinting if the time transfer relationship between the side pull gauge and the paper handing tooth is coordinated and accurate. The adjustment should be absolutely accurate to ensure that the side pull time and the transfer time do not interfere with each other.

2. The delivery paper teeth actually hold the paper as the standard, and adjust the time that the paper feed teeth are closed. We used to adjust the closing time of the paper-handling teeth by the fact that the open-closed tooth roller just disengaged from the closed-toothed bump. This traditional adjustment method will produce a large error. The reason is that during the process of closing the teeth of the paper feed teeth, when the open tooth roller goes down from the high point of the closed tooth bump, the two total springs of the paper feed shaft push the tooth shaft and the tooth pieces on the top to the teeth. The direction of the pad rotation, when the tooth piece just pressed between the tooth and the pad between the pad (that is, the delivery of paper on the paper just produce a force), the roller did not leave the closed tooth bumps, just from then on. The force acting on the roller of the closed-tooth protrusion begins to gradually decrease, and the tension of the total spring of the two delivery-feeding-shafts passes through the tooth shaft and the braces. Small springs and teeth, finally applied to the paper. The force on the tooth pad began to increase gradually. Only when the force acting on the roller by the closed-tooth projection gradually decreases to zero, the total spring tension of the delivery toothing is applied to the paper. When the force on the tooth pad reaches a maximum value, the opening and closing of the tooth roller begins to leave the closed tooth bump. From the beginning of the transfer teeth, there is force to hold the paper, and the process of leaving the closed bumps (maximum pick-up force) is generally 3°. If the strength of the paper-feeding teeth is too large or the strength of the teeth is uneven, the movement is inconsistent and the process will be longer.

3. Because the printed paper has a certain thickness, the correct time for picking up the side sheet should tear the printed paper into a paper strip and put it under the pull-off wheel for testing. The pull-out wheel is not suitable for the printed sheet, and should not be Take the pull-off roller and the knurled wheel just below the pull-off roller.

The above point of view is a problem that must be paid attention to when adjusting the time transfer relationship between the side gauge and the transfer paper.