Experience of the most popular maintenance of the

  • Detail

Experience in repairing the water roller support of the four-color machine

at the end of 1997, the company introduced a new Roland four-color offset press r7043b, which has been put into production for more than 6 years, with a total output of 160million prints. However, recently, the phenomenon of the jumping of the water roller support against the plate is relatively serious, which has brought many difficulties to normal printing. It is understood that the user's equipment failure is generally overhauled by the Roland office in China, which implements the replacement of a complete set of support combinations, but its maintenance cost is relatively expensive. Now let's talk about our experience in the maintenance process

fault phenomenon

1 The support of the water roller against the plate jumps

2. The impact sound of the glass fiber reinforced plastic tensile testing machine during the operation of the machine is large

3. The printing plate resistance decreases

4. The printing belt is dirty

negative effects

1 The water supply is uneven, the ink is unbalanced, and the prints are easy to get dirty. In addition, the ink path of this model is short, and the ink saturation of the prints is not enough, which is prone to the phenomenon of "gray, flat and light"

2. Due to the jumping of the water roller support against the plate, a large impact force is generated, so the machine speed cannot reach the set running speed, resulting in a waste of equipment potential, and it is easy to cause damage to other parts, thus affecting the overall printing accuracy of the machine

3. Due to the jumping of the water roller support against the plate, a large impact force is generated on the surface of the printing plate cylinder, which is easy to cause the printing plate to flower, and the printing resistance is significantly reduced, especially the printing resistance of the line plate will be lower, increasing the printing cost

4. Due to uneven water supply and the elimination of common faults, it is easy to cause uneven paper expansion, which affects the accuracy of overprint, and brings certain difficulties to the printing of fine prints

fault analysis and solutions

1 The support assembly of the water roller on the plate is composed of two fastening bolts, an adjusting screw equipped with several butterfly springs, two copper eccentric worm gears and a group of supports. The loosening or wear of any fastening part, copper sleeve and eccentric worm gear may cause the jump of the support

2 Check all parts of the water roller support assembly one by one, and repair and replace the worn parts. After careful inspection and analysis, we found that 008f21853, 008f217530 and 008g282230 were worn, the hole of support 11 light aggregate frame matched with 008g282230 was out of round, and 092g771840 elastic force was invalid

3. Due to the complex inspection and disassembly process of the water roller support combination of the operation surface and the transmission surface, there are many parts to be disassembled, so sufficient preparation should be made for the technical difficulties in the maintenance process

maintenance process

1 Trim the locating holes of the fixed wallboard that are out of round. Since this hole is a blind hole, it can be repaired with a straight reamer, and the specific size depends on the wear

2. Conduct surface treatment on the out of round positioning support shaft 008g282230 to restore its original function

3. Replace worn parts (008f21853, 008f217530, 091f154140, 092g771840)

maintenance effect

1 The phenomenon of the jumping of the water roller support has been fundamentally solved

2. The dirty phenomenon of products in the printing process has been thoroughly improved

3. The printing resistance of the printing plate increased significantly

4. The product quality has been improved

Author: Liu Jianbin et al.

reprinted from: Printing Technology

Copyright © 2011 JIN SHI