Fault injection molding machine maintenance

Date：2016-06-29 09:58:56

Injection molding machine repairs and maintenance in their daily work, companies often lack of awareness in this regard. Today's factory in production for lack of knowledge. We organize a special maintenance and fault causes related content.

    First, the injection molding machine malfunction classification

    Injection molding machine failures are diverse, it can be classified from different angles.

    1. Press the failure state can be divided into:

    (1) gradual onset fault. Is due to the gradual deterioration of the performance of the initial injection molding machines produced most of the injection molding machine fault belongs to this type of failure. Such failures and electronically controlled, hydraulic machinery yuan parts wear, corrosion, fatigue and creep processes are closely related.

    (2) sudden failure. Various unfavorable factors and accidental external influences interaction arising from this effect is beyond the limits of the injection molding machine can bear. For example: Because the cartridge into the iron overload was caused by the screw appears broken; and breakdown due to high pressure injection molding machine series with the electronic board. Such failure often occurs suddenly, without any advance warning. Sudden failure occurred in the injection molding machine stage, often due to the design, manufacture, assembly and material defects, or operational errors, caused by illegal operations

    2. Press the nature of the fault can be divided into:

    (1) intermittent fault.

    Injection molding machine in the short term loss of some of its features, debugging can resume a little repair, no replacement parts.

    (2) permanent failure.

    Some parts of the injection molding machine is damaged, it needs to be replaced or repaired to resume use.

    3. Failure impact can be divided into:

    (1) complete failure. Resulting in complete loss of function of the injection molding machine.

    (2) partial failure. Leading to some loss of function of the injection molding machine.

    4. Press the fault causes division, can be divided into:

    (1) Wear failure. Since the injection molding machine to normal wear and tear caused by the failure.

    (2) misuse failure. Because of a mistake, a failure caused by improper maintenance.

    (3) the inherent weakness of the fault. Because of design issues, makes injection molding machine appears weak link fault generated during normal use.

    5. Press the risk of failure of the division, can be divided into:

    (1) the risk of failure. Such as security systems when action is required due to failure to lose the protective effect, causing personal injury and failure of injection molding machine; hydraulic electronic control system malfunction caused by failure.

    (2) security failures. Security systems such as the action occurs when not in operation; when the injection molding machine can not start Failure to start.

    6. Press the injection molding machine failure occurs, the law of development can be divided into;

    (1) random failures. Time failure is random.

    (2) fault rules. Occurrence of failure there are certain rules.

    Each fault has its main characteristics, the so-called failure mode or fault condition. Fault status of various injection molding machine is quite complex, but can be summarized in the following several kinds: abnormal vibration, mechanical wear and tear, so that the computer can not accept the input signal, the output signal of the solenoid valve is not, Hydraulic component rupture ,, linear ratio imbalance, hydraulic pressure drop, hydraulic leaks, oil pump failure, hydraulic noise, circuit aging, abnormal noise, oil deterioration, the power supply voltage drop, no output amplifier board, and other thermal runaway. Various failure modes of different types of injection molding machine of the proportion of different.

    Second, the failure analysis and troubleshooting procedures

    To ensure fault analysis and elimination of fast, efficient, must follow certain procedures, such a procedure is as follows.

    Diagnostic analysis of the case of the first step in keeping the scene

    1. ask the operator

    ① fault what happened? Under what happens? When did it happen?

    ② injection molding machine has already started running how long?

    ③ before failure or absence of any abnormality? What sound or audible alarms? Have smoke or odor? Have misuse (note the manner of questioning)?

    ④ whether the control system is operating properly? Have changes in operating procedures? In operation if there are special difficulties or abnormal?

    2. Observe the status of the machine, the operating parameters

    ① whether the apparent anomaly? Have parts jam or damage? No hydraulic system for loose or leak? Wires for cracks, scratches or burn?

    ② injection molding machine operating parameters change? Have obvious interference signal? Without obvious damage to the signal?

    3. Check the pointing device monitoring

    ① Check that all readings are normal, including pressure gauges and other instrument readings, oil level conditions.

    ② Check the filter, alarm and interlock operation output or display properly.

    ③ Jog injection molding machine inspection (under allowable conditions) Check the batch, the persistent situation, the situation is fast forward or slow forward when to see whether in these circumstances affect the output, the possibility of causing damage or other hazards.

    Step Check injection molding machine (including parts, components and lines)

    Use sensory test (continue in-depth process of observation)

    1 See: plug and socket whether the abnormal operation of the motor or pump is normal, control setting is correct, with or without arcing or scorch marks, the fuse is good or bad, fluid leaks, lubricating oil passage is smooth and so on.

    2 touch: injection molding machine vibration, Yuan (Group) member of heat, tubing temperature, state of the mechanical movement.

    3: any abnormal sound.

    Olfactory 4: Have a burning smell, the smell of leaking other odors.

    5 check: the shape and position of the workpiece changes, changes in the injection molding machine performance parameters, checks line anomalies. 2. Review

    Given the test results

    Evaluation of fault diagnosis is correct, whether the failure to find the clues, the test results are the same.

    The third step is to determine the fault location

    1. Identify the system configuration and test methods to determine

    Now manual injection molding machine, injection molding machine to identify what kind of structure, the method used for testing, what testing means necessary, what test parameters or performance parameters may be obtained, under what operating conditions tested, which must comply with safety measures, if needed operating license.

    2. The system detects

    Using the technology best suited to detect the system configuration. In a suitable test points, based on input and feedback results obtained with normal or performance standard for comparison, to identify suspicious position.

    The fourth step to repair or replace

    1. Repair

    Find the cause of the malfunction, repair of injection molding machines for the failure and take preventive measures; check the relevant parts to prevent failure from spreading.

    2. Replace

    Correct assembly debugging replacement parts and note the relevant parts. Replacement part for repair or scrapped.

    The fifth step performance measurement

    1. Start injection molding machine

    Parts assembly debugging start the injection molding machine, manually (or jog) and then load and load measurement.

    2. Adjust the load changes from low to high speed, small to large loads, the system pressure can not exceed 140kg / cm2, measured according to the standard performance.

    3. To expand the scope of the performance test

    If necessary, by the local system to gradually expand the scope of performance testing. Note that non-fault zone system health. Such as performance to meet the requirements are delivered, as it does not meet the requirements to re-determine the fault position.

    The sixth step and record feedback

    1. gather valuable information and data, such as time of injection molding machine failure, the failure phenomenon, downtime, when the repairman, repair replacement parts, repair effects, problems to be solved, settlement costs, according to the requirements stored in archives .

    2. Statistical Analysis

    Regular analysis of the injection molding machine record, downtime analysis, revision notes directory to find the key measure to reduce maintenance work, study failure mechanism, suggest improvements.

    3. Press the program feedback about the failure to report the competent authorities, and feedback to the injection molding machine manufacturing units.

    Third, expand Incident Management Program

    To do the injection molding machine fault management, must grasp the reasons for failure, permanent fault accumulation and typical fault information and data, carry out fault analysis, fault law emphasis on research and failure mechanisms, strengthen routine maintenance, inspection and preventive maintenance.

    Expand fault management program has the following eight aspects.

    1. improving information and education, so that operation of the workers and maintenance workers consciously serious fault injection molding machine records, statistics, analysis, rationalization proposals.

    2. The close connection with the actual production and injection molding machine status features, using the injection molding machine is divided into A, B, C categories, in order to determine the fault management focus.

    3. The use of monitoring instruments, focus on key parts of the injection molding machine in a planned monitoring, and found signs of failure and degradation of information.

    General injection molding machine to go through the human senses and the general detection tools for routine inspection, patrol inspection, periodic inspection (including precision inspection), good condition inspection, focusing on master failure-prone parts of the state institutions and technical part and abnormality phenomenon of information. The same time to develop inspection standards to determine the injection molding machine normal, abnormal, fault boundaries.

    4. Conduct failure analysis, training to master the injection molding machine repairman fault analysis.

    5. Fault recording is the basis of data of injection molding machine fault management, but also the failure analysis, based on the original process, records must be complete and accurate. After the injection molding machine maintenance worker at the site for inspection and fault repair should be in accordance with "single injection molding machine troubleshooting," the contents of fill, mechanic workshop and submit monthly statistical analysis of the injection molding machine managing director.

    6. The workshop injection molding machine maintenance staff In addition to routine failure to grasp the situation, the month should bring together "troubleshooting list" and maintenance records. Through the fault data statistics, collation, analysis, calculate the frequency of various types of injection molding machine failure, MTBF of fault analysis dynamic single injection molding machines and key problems, identify Occurrence of failure to take focus Countermeasures, fault information collation analyzing information fed back to the planning department to arrange for repairs or improvements prevention programs can also serve to modify the regular inspection intervals, and check the contents of the standard basis.

    According to statistical data compiled, you can draw statistical analysis of the chart, such as a single injection molding machine fault analysis table is dynamic statistical breakdown maintenance team and other effective methods of visual management, both for managers and maintenance workers to grasp the various types of injection molding case a problem occurs, but also have a clear goal when determining maintenance countermeasures.

    7. Adoption of the routine maintenance inspection tour of workers and injection molding machine status check, and fault status information signs made, and the relevant records, data analysis, by the injection molding machine repair shop clerk or repair problems for all types of leader of injection molding machines, in a timely manner schedule routine maintenance and take advantage of the production gap time or holidays, so prevention front, to control and reduce failure. For some fault symptoms, risks, routine maintenance can not afford, then back to the planning department to arrange unscheduled repairs.

    8. Development of fault information management flowchart.

    Fourth, the injection molding machine fault law

    Research on Fault law of development of maintenance measures, as well as to establish a scientific system maintenance are very favorable. Injection molding machines in use, or performance status over time and gradually decline. There will be a lot of failure before some of the warning, which is called a potential failure, which can identify the physical parameters indicate that a functional failure is imminent, functionality failure showed that the loss of the injection molding machine specified performance standards.

    Injection molding machine failure rate variation with time, often called the bathtub curve.

    Injection molding machine failure rate over time can roughly be divided into three stages: early failure period, occasional failure period and wear and tear failure period.

    1. Early failure period

    Injection molding machine in the early failure period, began a high failure rate, but the passage of time the failure rate drops rapidly, early failure of mechanical products, also known as the run-in period. The length of this period, due to the design and manufacture of quality products, systems varies. Failure occurred during this period, mainly by defects in design, manufacturing caused by, or caused by improper use of the environment.

    2. The occasional failure of

    Injection molding machine into the occasional failure period, the failure rate is substantially stable state, tend to value. During this period, failure is random. The lowest failure rate in the accidental failure period, the injection molding machine, and stable. Thus it can be said that this is the best state of the injection molding machine or called normal working period. This section is called the effective life.

    The occasional failure of failure due to multiple design, improper use and inadequate maintenance. Therefore, by improving the quality of design, use and management improvement, strengthening surveillance and diagnostic maintenance, etc., can reduce the failure rate to the lowest level.

    3. The loss of fault

    In the latter part of the injection molding machine used, the failure rate began to rise. This is due to the injection molding machine parts to wear, fatigue, aging, corrosion caused. If that is the turning point for a major overhaul in depletion fault of the beginning, it can be economically and effectively reduce the failure rate.

    Three stages of the injection molding machine failure rate curve, and a true reflection of the injection molding machine from running, debugging, normal work to overhaul or scrap failure rate of change of the law, strengthen the daily management of the injection molding machine and maintenance, occasional failure period can be extended. Accurately identify the inflection point, to avoid excessive repair or expand the scope of repairs in order to get the best investment returns.

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