Core of repair work of injection molding machine is judgment of fault and treatment of fault. It involves a wide range of knowledge, a large degree of complexity, and a certain depth (such as comprehensive professional knowledge level). It is necessary to have basic knowledge of mechanical equipment maintenance, basic knowledge of hydraulic maintenance, and basic knowledge of electrical maintenance.

 

In fact, maintenance of injection molding machine is difficult, but it is also a process of continuous learning and progress. As long as you master basic working principle of injection molding machine and master basic working methods, regardless of various models, you can explore a set of maintenance procedures to ensure normal operation of injection molding machine.
Maintenance workers must first understand and master contents of operating instructions of injection molding machine, be familiar with and master mechanical parts, circuits and oil circuits of injection molding machine, understand working process of mechanics, circuits and oil circuits during normal operation of injection molding machine, understand and master inspection and maintenance methods of electrical components and hydraulic components. Know normal working state and abnormal working state to avoid time-consuming misjudgment and wrong disassembly.
Maintenance work must understand operation method of equipment and have some basic knowledge of injection molding, and be able to use injection molding machine correctly. If you don’t know how to operate an injection molding machine, maintenance work is very difficult, and it may be unreliable to judge fault. Circuit boards and electrical components in injection molding machine are affected by factors such as high temperature, environment, and time for a long time, operating point of components is shifted, aging degree of components is within normal range.
Therefore, debugging an injection molding machine is also one of essential basic skills in maintenance work. Understanding working procedures of injection molding machine, debugging electronic circuit and hydraulic circuit of injection molding machine are very important links.
To be accurate, reliable and timely in maintenance work, it is necessary to study and master contents of operating instructions of various types of injection molding machines. In general maintenance process, maintenance idea is usually circuit- oil circuit- action of mechanical parts. Adjustment work is carried out in reverse. If mechanical action and clamping pressure are insufficient, oil circuit and circuit can be found. If circuit output is normal, oil circuit valve should be adjusted.
If oil circuit works normally, adjust circuit electronic board. Of course, final coordination, but relationship between the three is interdependent and mutual control. Correct use of instruments and meters, adjustment of detection circuits, inspection and repair of oil circuits, adjustment of position and actions of mechanical parts are important means of judging failures.
Generally, injection molding machine manufacturers only provide electrical block diagram of equipment, block diagram of oil circuit and main parts of machinery, which is not enough for maintenance work. Must pay attention to daily maintenance work, collect and sort out all aspects of relevant information, such as electrical, electronic, mechanical spare parts, oil circuit, solenoid valve body and other aspects.

 

For example, if there is an opportunity in electrical aspect, it is necessary to survey and map schematic diagram of circuit, schematic diagram of electronic board and actual wiring diagram, and measure relevant information such as components corresponding to wiring terminals, so as to provide accurate detection points for fault judgment and analysis during maintenance.
Measure specific parameters of detection point. When necessary, you must also make your own power supply, simulate input and output signals, perform simulation tests or adjustments to master and obtain first-hand maintenance data, such as parameters at various levels of work points.
Same is true for oil circuit maintenance, which must be adjusted and maintained according to characteristics of oil circuit and oil pressure solenoid valve. Have opportunity to frequently disassemble, clean, inspect, and install the solenoid valve. These treatments will cause a lot of trouble, but they are crucial.
Maintenance work must be mastered and sorted out in line with principle and logical system failure maintenance methods and judgment program diagrams, combined with actual maintenance work on weekdays, collect relevant information of injection molding machine, deal with it immediately if there is a fault. Methods include step-by-step inspection, simulation inspection, voltage testing, continuity testing, circuit board replacement and other methods.
After repairing, it is necessary to re-adjust operating point, re-adjust, and carry out a load test to make equipment work within parameter range of data listed in operation manual.