Both imported and domestic injection molding machines have following characteristics:
Injection molding machine has large investment in fixed assets, large production scale, large consumption of raw materials, high labor productivity, and large output value. It is a form of production organization with high labor efficiency.
Injection molding machine is composed of machinery, hydraulics, electrical appliances, special accessories, etc., which are organically combined according to needs of injection molding process technology. If a component of injection molding machine fails, it will cause a shutdown.
Although operation of injection molding machine is simple and number of workers is small, management and maintenance of injection molding machine has a high technical content and a large workload. Therefore, to ensure that injection molding machine is always in good condition, it is necessary to strengthen management of injection molding machine and strictly control failure of injection molding machine.

 

In order to achieve purpose of reducing failure rate, reducing maintenance costs and prolonging service life. Injection molding machine failure generally refers to event or phenomenon that injection molding machine or system loses or reduces its specified function during use. Injection molding machine is equipped by enterprise to meet production process requirements of injection molding products.
Function of injection molding machine reflects its value in production activities of injection molding products and degree of guarantee for injection molding production. In production of modern injection molding machines, due to complex structure of injection molding machine, high degree of automation, and close connection between hydraulic pressure, electrical control and machinery, failure of injection molding machine, even if it is a partial failure, will cause entire injection molding machine to stop production. Failure of injection molding machine directly affects quantity and quality of injection molding products.
In order to ensure fast and effective fault analysis and troubleshooting, certain procedures must be followed, which are roughly as follows:

1. Ask operator
What's wrong? Under what circumstances did it happen? When did it happen?
How long has injection molding machine been running?
Was there any abnormality before failure occurred? Are there any audible or audible and visual warning signals? Is there any smoke or odor? Is there any wrong operation (pay attention to way of asking)?
Is control system operating normally? Has operating procedure changed? Are there any special difficulties or exceptions in operation?
2. Observe status of the whole machine and various operating parameters
Are there any obvious abnormalities? Are parts jammed or damaged? Is hydraulic system loose or leaking? Is wire broken, scratched, or burned?
What are changes in operating parameters of injection molding machine? Are there any obvious interfering signals? Are there any obvious signs of damage?
3. Check monitoring and indicating device
Check whether all readings are normal, including pressure gauge and other instrument readings, and oil level.
Check that filters, alarms and interlocks, action outputs or displays are normal.
4. Jog injection molding machine inspection (under permitted conditions)
Check for intermittent conditions, persistent conditions, conditions during fast forward or slow forward, to see if these conditions affect output and may cause damage or other hazards.

1. Use sensory inspection (process of continuing to observe deeply)
Check: whether plug and socket are abnormal, whether motor or pump is running normally, whether control adjustment position is correct, whether there are traces of arcing or burning, whether fuse is good or not, whether there is liquid leakage, whether lubricating oil path is smooth, etc.
Touch: vibration of injection molding machine, heat of element (component), temperature of oil pipe, and state of mechanical movement.
Listen: Whether there is any abnormal sound.
Smell: with or without burnt odor, leakage odor, and other peculiar smells.
Inspection: Changes in shape and position of workpiece, changes in performance parameters of injection molding machine, and abnormal circuit inspection.
2. Evaluate inspection results
Evaluate whether fault judgment is correct, whether fault clues are found, and whether inspection results are consistent.

1. Identify system structure and determine test method
Refer to instruction manual of injection molding machine to identify what kind of structure injection molding machine is, what method to use for testing, what testing methods are required, what test parameters or performance parameters may be obtained, under what operating conditions test is performed, what safety measures must be followed, and whether an operating license is required.
2. System detection
Check with technology most suitable for system structure. At appropriate test points, results obtained based on input and feedback are compared with normal values or performance standards to identify suspicious locations.

1. Repair
Find cause of failure, repair and take preventive measures against failure of injection molding machine; check relevant parts to prevent failure from spreading.
2. Replace
Correctly assemble and debug replacement parts, and pay attention to related parts. Replaced parts are repaired or scrapped.

1. Start injection molding machine
After parts are assembled and debugged, start injection molding machine, first manually (or jog), then measure no-load and load.
2. Adjust load change speed from low to high, load from small to large, maximum system pressure cannot exceed 140kg/cm2, and measure performance according to specified standards.
3. Expand scope of performance test
According to needs, gradually expand performance test range from local to system. Note non-fault zone system health. If performance meets requirements, it will be delivered for use, and if it does not meet requirements, fault location will be re-determined.

1. Collect valuable information and data
Such as occurrence time of injection molding machine failure, failure phenomenon, downtime, repair man-hours, replacement parts, repair results, problems to be solved, settlement costs, etc., are stored in file according to specified requirements.
2. Statistical analysis
Regularly analyze use records of injection molding machines, analyze loss of downtime, revise memo catalog, find key measures to reduce maintenance operations, study failure mechanism, and propose improvement measures.
3. According to procedure, report fault to competent department and report it to injection molding machine manufacturing unit.