What is the focus of gravure printing machine maintenance

2020-12-22 15:34:03 浙江紫明印刷机械有限公司 Viewd 53

The following points fully illustrate the importance and necessity of equipment maintenance:


1. The oil circuit


In terms of oil circuit, lubrication of production equipment is an important part of equipment maintenance. Keeping the oil circuit of the printing machine unblocked is related to the lubrication of the flowing parts of the whole machine. It is necessary to change the oil and clean the oil through the filter device on schedule to ensure that the oil flowing into the pipeline does not contain impurities and avoid blockage of the oil passages of the department. Especially the needle roller bearing of a unit supporting the roller, if there is no lubrication and cooling of the oil, it will cause long-term dry friction between the bearing and the roller shaft. When an abnormality is found, the shaft and the inner ring of the bearing have been glued. Replace the inner ring for the lighter ones; for the heavier ones, the roller shaft is severely damaged.


2. Mechanical angle


From a mechanical point of view, only the equipment operators must strengthen maintenance to keep the mechanical fluid parts of the machine clean and lubricated, and operate flexibly in order to fully display the technical functions of the equipment and keep the equipment in good condition. Anyone who has used a printing press knows that the bearing seats of the inking roller and the water roller of the multi-color printing press and the pressure regulating worm seat are the most vulnerable to wear. If the gold and silver ink unit cannot be cleaned in time, the metal particles will accelerate the wear of the bearing seat or worm seat after a long time. Generally, it takes several hours to remove the worn inking roller bearing seat from the wall of the machine. Since the bearing seat is fixed on the lifting mechanism with a shaft retaining ring, the space is extremely small, with only a few centimeters of loose position. It takes time for the reflector to find the two holes on the retaining ring and to take out the retaining ring to reinstall the bearing seat and its lifting mechanism. The same applies to the installation and disassembly of the water roller seat. Different multi-color offset printing machines have different installation methods for the pressure regulating worm seat: one is that the fixing bolts of the fixing seat are fixed and locked from the outside to the machine wall (easy to install and disassemble); the other is that the fixing bolts are from the machine wall Lock outwards (most of them use this method), the space is narrow, assembly, disassembly and maintenance are difficult. If the machine staff understands this, they can maintain and keep clean at ordinary times, and remove the ink accumulated on the machine in time, so there is no need to frequently replace the bearing seat and worm seat. This can not only reduce downtime, improve production efficiency, but also save replacement costs.


In order to prevent smearing of printed matter, offset printing machines generally use powder spraying. If the amount of powder sprayed is too large and cannot be cleaned up in time, it will also cause some failures, such as failure of the automatic lifting device for paper delivery and damage to the paper suction reduction wheel shaft mechanism. It is worth mentioning that the suction reduction wheel of the paper delivery device of the Heidelberg offset printing machine. If the dust near the axle and the suction reduction belt cannot be removed in time, the powder and the engine oil are mixed to form sludge, and the sludge will stick to the suction after a long time. The air reduction wheel shaft prevents it from rolling. In order to protect the motor that drives the reduction wheel shaft to roll, the gears in the reduction mechanism are forced to peel off or sweep teeth. The motor is also related to the circuit of the dampening system. Once a failure occurs, the whole machine will stop. To troubleshoot, you need to install a new gear. Therefore, clean these mechanisms more often, otherwise, the machine can only print thick-for support. If you print thin paper, because the suction speed wheel does not work, it will cause paper messing in the delivery mechanism and reduce production efficiency.


3. Electrical aspects


The offset printing machine is equipped with many safety devices and is very agile. As long as it is touched slightly, the whole machine will stop running. Sometimes too much dust accumulates at the relay contacts in the electrical control box of the machine, causing poor contact of the relay contacts and making the machine unable to operate.

There are many other similar problems. For example, excessive dust accumulation in the motor will image the movement and resetting of the carbon brush holder, and the pressing force of the spring on the carbon brush holder against the carbon brush, making the carbon brush and the commutator copper head Poor contact can also cause problems for machine operation.


4. Airway


The four-color and five-color offset presses produced in the late 1980s all used starters to control the cylinder clutch pressure, the release of the ink roller and the water roller, and the ink transfer roller. Each unit of the multi-color printing machine has several two-position five-way control valves to control these actions. The movement of the cylinder piston can be controlled by the control valve to realize the inking roller, the water roller and the ink transfer roller. Sometimes, the air valve seal is damaged because of the water in the control valve or the air cylinder, which causes the control valve or air cylinder to leak air, which makes the inking roller and the water roller separate from the plate. In addition, because the ink accumulates in the action control mechanism, the movement of these flowing parts is not flexible, which increases the burden on the control valve and the air cylinder, resulting in fragile sealing of the control valve and easier deformation of the air cylinder piston. In addition, because of the aging of the gas hose, the pipeline leaks, and the pipeline pressure drops rapidly, so that the control valve cannot be opened, and the clutch pressure action cannot be completed. If the pressure is increased, the life of the image compressor will further accelerate the aging of the hose. Therefore, it is not thorough to solve the problem of the unsmooth lifting mechanism by changing the pressure of the air valve or the air cylinder. These operating mechanisms are often cleaned to maintain flexible operation. , The long-term solution is to ensure that the air path does not leak air and does not accumulate water.


All these problems are caused by poor maintenance. Therefore, it is important to strengthen maintenance and do daily, weekly and monthly maintenance. It can not only extend the service life of the printing machine, but also improve the production efficiency.