Exclusion of difficult problems in offset printing (six)

Section 3 Judgment of Abnormal Sound of Mechanical Parts
As a skilled craftsman operating an offset press, he or she should develop ear hearing skills in daily production. Because there are many parts in the offset press, the sound produced by various parts during operation has a fixed tone and beat, and the operator has to distinguish which part sounds change and find problems. Auditory skills are particularly important for ensuring the safe operation of equipment, because most of the components of a modern offset press are enclosed in a shell and cannot be seen by eyes or touched by hands. The only thing that can be felt is that it is emitted during operation. Voice, which requires that in the usual work, pay attention to the sound of the machine when it is normal, and listen carefully. For the average operator, the minimum requirement is to “smell the sound and check the disease.” If it stays at this stage, it is obviously not enough. The operators who really have the skills must strive to achieve “sound and illness”. This "sound and illness" is an amazing skill, and it should not even be included in the provisions of the Council. The following are some rough understandings of the author in practice.
First, the parts outside the hood when the work is not abnormal sound 1J2108, J2203, J2201 type offset press in the anti-point, sometimes issued a "吱 - 啪哒 啪哒 啪哒 啪哒 啪哒" sound, "吱 吱 比较 比较" sound is more sharp, "啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 啪哒 sounds louder but it seems not ne This is the sound of the swinging tooth tip against the blank edge of the impression cylinder. Or it is the sound of the blank edge of the delivery stamping tooth against the blank side of the impression cylinder. Due to the sharp cusp, when the anti-point scratches the roller while sliding on the open side of the drum, it will inevitably produce a sharp "click" sound. When the teeth are closed, the "click" sound is not neat and tidy. This is because the cusps are short and short. Close your teeth, long scratching the gap and slowly closing your teeth, so the "click" will not be neat.
The oscillating tooth tip touches the blank side of the impression cylinder, and the position of the large cam can be adjusted or the diameter of the roller can be enlarged; the receiving tine can touch the blank side of the impression cylinder to adjust the running time of the paper teeth row as a whole. .
2 When the drum is pressed and operated, it will sound “嘭, 嘭 , , ,” and at a glance, the pressure on the machine will be too great. Occasionally, a "slightly, slightly, slightly" sound is produced, and the plate is not taut or broken. The former need to reduce the pressure between the rollers, the latter need to be tightened or replaced with a new plate.
3 When the paper stack is full of paper, the paper feeder sends out sharp, intermittent sounds like each sheet of paper. This is when the small paper stoppers hit the transfer roller. Loosen the middle foot screw and allow the foot to sink a little.
4 The stack of paper rises upwards. The “吸, 嗒, 嗒” of the suction iron continues to ring continuously and the pile of paper does not rise. This is the pin of the continuous iron core is broken or is about to slide out. It should be stopped immediately. Get it done.
5 During the printing process, a "bump-projection-projection" sound is emitted for each printed piece of paper. This indicates that the pressure of a certain water and ink roller on the printing plate is too great. Because the ink roller and the water roller are made of rubber, the sound produced is boring. To check which one? Whether the adjustment screw to move around? Then regulate.
â‘¥ delivery portion of the machine from below "cracking, cracking, cracking" sound, which is due to the long delivery chains, rejection during cornering force generated in the element row on the rails, should be properly tightened on both sides of the delivery chain .
7 Take-up pile empty The platen rises too high and hits the suction lever of the delivery paper. The suction wheel will give a “buzz-sound” sound, which can move the suction eyes down a bit and the sound should be Will disappear.
These are often audible tone different troubleshooting.
Second, sound ① hood inner part of the hood inner part emitted is most prone to damage the ball bearing, more particularly the drive side, such as the large roller swing cam carrier gear portion like the gear sets are fitted with ball bearings. After the ball bearing damage on the gears, the gear operation will be issued in the "Honghong" sound, which is mainly not normal gears, tooth flank friction emitted excess, typically accompanied by "Honghong" sound. When these sounds are found, the cover should be opened for further inspection. Sometimes it is difficult to determine which component is part of the cover once it is opened. At this time, it can be determined by the “auscultation method”. The specific method is: using a long-handled screwdriver, the blade contacts the parts, the handle is placed in the ear, which machine There is a problem with the piece, and the sound coming from the handle into the ear will be different. With this “listening method”, the proportion of “diseases” can be said to be 100%, which can reduce the need for unnecessary repeated demolition. This kind of "auscultation method" can also be applied to correct other diseases such as motor malfunctions.
2 When the machine stops suddenly, it can be confirmed that parts such as hard screws have fallen off, and the “stingy car” failure caused by the failure of the safety device at the paper feeding position has occurred. If the machine is gradually stopped, it is generally caused by the lack of oil in the major parts of the paper, such as between the rollers or the drum sleeve. When there are no obstacles to the multi-party search, the detachable boot can touch the shaft sleeve and other parts one by one. If hot or hot parts are found, it can be confirmed that this part is caused by lack of oil. Bushings worn in shaft sleeves caused by debris are generally not present on modern offset presses except for manual refueling sites because the automatic lubrication mechanism has multiple layers of filters and filters. However, some oil pipelines are broken, and the oil-losing shutdown caused by the blockage phenomenon also occurs from time to time.
When there is a sudden stoppage of the machine, the operator should immediately turn off the main motor to prevent unnecessary loss of the motor. If it is found that the blanket slides out of a long mouth and does not stop, it means that the parts rolled in between the rollers are slipped into the machine pit from the empty position of the roller, and the machine should be shut down immediately to check the cause.