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Plastic injection molding machine failure and troubleshooting in general 0 replies,2414 views


Whether imported or domestic injection molding machine has the following characteristics:
 1. Injection molding machine of fixed assets investment, scale of production, consumption of raw materials and more high labor productivity, the output value of large.  Is a labor efficient forms of production organization.
 2. Injection molding machine consists of mechanical, hydraulic, electrical, special auxiliary equipment, injection molding technology in accordance with the needs of organically combined high degree of automation, closely related to each other; injection molding machine in 3 classes 24h continuous operation.  If a component injection molding machine failure will result in downtime.
 3, although the injection molding machine is simple, the laborers are few, but the management and maintenance of injection molding machines with high technical content, the workload is also large.
 So often in injection molding machine to ensure good condition, we must strengthen the management of injection molding machines, and strictly control the injection molding machine failure.  To achieve lower failure rate, reduce maintenance costs, extend service life.
 Fault injection molding machine, generally refers to the injection molding machine or system in use, or reduce the loss of events or phenomena required function.  Injection molding machine is the enterprise manufacturing process to meet the requirements of injection molding products equipped.  Function of injection molding machine injection molding products, it embodies the present value of production activities and the level of assurance of the injection molding.  In the modern production of injection molding machine, injection molding machine as complicated structure, high degree of automation, hydraulic, electronic control and mechanical contact is very close,
 Thus injection molding machine failure, even a partial failure, will result in the injection molding machine production.  Injection molding machine failures directly affect the quantity and quality of products.

 First, the classification of fault injection molding machine

 Injection molding machine failure are varied and can classify them from different angles.
 1. By fault state, can be divided into:
 (1) gradual onset of failure.  Initial performance is due to the gradual deterioration of injection molding machine generated, most of the breakdown of injection molding machines are such failures.  Such failures and electronic control, hydraulic machinery parts per wear, corrosion, fatigue and creep processes are closely related.
 (2) unexpected failure.  A variety of adverse effects of external factors and a common accident caused by the interaction, and this effect than the injection molding machine can bear.  For example: due to barrel into the iron overload caused by screw things appear broken; breakdown due to high pressure injection molding machines in series and electronic board.  Such failure is often sudden, without any sign of advance.
 Sudden failure occurred in the injection molding machine using the stage, often because of the design, manufacture, assembly and material and other defects, or operational errors caused by illegal operations.
 2. By the nature of failure can be divided into:
 (1) intermittent failure.  Injection molding machine in the short term loss of some of its features, debugging will be able to recover a little repair, no replacement parts.
 (2) permanent fault.  Some parts injection molding machine has been damaged and need replacement or repair can be restored to use.
 3. By failure impact can be divided into:
 (1) complete failure.  Lead to complete loss of function of injection molding machine.
 (2) partial failure.  Injection molding machine causes some loss of function.
 4. According to the causes of failure can be divided into:

 (1) wear and tear failures.  The injection molding machine failure caused by normal wear and tear.
 (2) misuse of failure.  Due to operation errors, failures caused by improper maintenance.
 (3) the inherent weakness of the fault.  As the design problems so that injection molding machine appears weak links in the normal use failures.
 5. At the risk of failure can be divided into:
 (1) risk of failure.  For example, security systems need to move out due to malfunction protection, resulting in personal injury and injection molding machine breakdown; hydraulic electronic control system malfunction caused by such failure.
 (2) security problems.  Such as security protection system in action when no action; injection molding machine can not start at boot time failures.
 6. By injection molding machine failures occur, the law of development can be divided into;
 (1) random failure.  Failure occurred at a time is random.
 (2) the rules failed.  The occurrence of certain laws fault.
 Each fault has its main features, the so-called failure mode, or fault condition.  Fault status of various injection molding machine is very complicated, but can be summarized as the following species: abnormal vibration, mechanical wear, can not get the computer to accept input, no output signal electromagnetic valve, mechanical breakdown of hydraulic components, the ratio of linear disorders, hydraulic pressure drop, hydraulic leaks, pump failures, hydraulic noise, circuit aging, abnormal noise, oil degradation, power supply voltage drop, zoom board no output, temperature control and more.  A variety of different types of injection molding machine is different from the proportion of failure modes.

 Second, failure analysis and troubleshooting procedures

 Troubleshooting To ensure the efficient, effective, must follow certain procedures, such procedures as follows.
 The first step to keep the symptoms under field analysis of the case 1. Ask the operator what happened a failure?  Under what circumstances did it happen?  When did it happen?
 2, injection molding machine has already started running for how long?
 3 Are there any unusual failure phenomenon before?  What sound or sound and light alarm signals?  Without smoke or smell?  Whether the misuse (note asking way)?
 4 control system operation is normal?  Whether the change in operating procedures?  In operation, whether there are special problems or unusual?
 2. Observe the whole situation, whether the operating parameters of an apparent anomaly?  Parts without jamming or damage?  Whether loose or hydraulic system leak?  Wire without rupture, abrasion or burn?
 2, injection molding machine operating parameters change?  Without significant interference signal?  Without obvious damage to the signal?
 3. Check the monitor indicating device 1 Check that all readings are normal, including pressure gauges and other instruments readings, oil level situation.
 2 Check the filter, alarm and interlock devices, motor output or display correctly.
 4. To move the injection molding machine check (under the conditions allowed)
 Check the condition of intermittent, lasting condition, fast forward or slow into the circumstances to see whether in these circumstances affect the output, it may cause damage or other hazards.
 Check the second step injection molding machine (including parts, components and circuits)
 1. By sensory inspection (to continue in-depth observation of the process)
 1 view: plug and socket without exception, the motor or the pump is functioning properly, the control to adjust the correct position, with or without signs of arcing or burning, fuses quality, liquid leaks, lubricating oil is smooth and so on.
 2 touch: vibration injection molding machine, Yuan (Group) pieces of the heat pipe temperature, mechanical movement of the state.
 3: any abnormal sound.
 4 Oh: whether the burnt smell, drain smell, and other odors.
 5 investigation: the shape and position of the workpiece changes, changes in performance parameters of injection molding machine, line exception checks.
 2. Assessment of test results to determine whether the correct assessment of failure, failure leads are found, the test results are the same.
 The third step is to determine fault location 1. Identification of System and method for determining access to the test manual injection molding machine, injection molding machine which identify a structure, the method used for testing, what testing means, what the test parameters may be given or performance parameters, What operating conditions in the test, which must comply with safety measures, the need for an operating permit.
 2. The system detects the most suitable system architecture to detect.  In the appropriate test points, results based on input and feedback or performance standards with the normal compared to identify suspicious locations.
 Step 1 repair or replacement. Repair troubleshooting reasons, for failure to repair and injection molding machine to take preventive measures; check the relevant parts, to prevent the spread of failure.
 2. Replace the correct replacement parts assembly debugging, and attention to the relevant parts.  Replaced parts for repair or scrapped.
 Determination of Step 1 performance. Starting after the injection molding machine parts assembly debugging start injection molding machine, the first hand (or jog), then no-load and load determination.
 2. Adjust the rate of load change from low to high, the load from small to big, the system pressure can not exceed 140kg/cm2, determination of the required performance standards.
 3. To expand the scope of performance tests as required by the local to the system and gradually expand the range of performance tests.  Note that the health of non-fault zone system.  If performance is delivered to meet requirements, such as not meeting the requirement is to re-determine the fault position.
 Step Six records and feedback 1. Collect valuable information and data, such as injection molding machine failure time, failure phenomena, downtime, repair time, repair parts replacement, repair results, to be resolved, settlement costs, according to requirements into the file.
 2. Statistical analysis of records of regular analysis of injection molding machines used to analyze downtime, revision notes directory, looking for the key measures to reduce the maintenance work, study the failure mechanism, suggest improvements.
 3. According to the procedure of the fault reported to the competent department of the feedback, and feedback to the injection molding machine manufacturing units.

 Third, the fault management of the expansion process

 Injection molding machine fault management to do well, must have the cause of failure, the accumulation of permanent fault and typical fault information and data, conduct failure analysis, attention to failure and failure mechanism of law, strengthening routine maintenance, inspection and pre-repair.  Expand fault management program has the following eight aspects.
 1. To do propaganda and education workers and maintenance workers to operate consciously serious failure on the injection molding machine records, statistics, analysis, rationalization proposals.
 2. Closely with the actual production and injection molding machine injection molding characteristics of the situation, the injection molding machine in use is divided into A, B, C three, to determine the fault management focus.
 3. Using monitoring instruments, focusing on key parts of the injection molding machine in a planned monitoring, and found signs of failure and deterioration of the information.
 General injection molding machine to go through the human senses and general testing tools for daily spot check, mobile inspection, regular inspection (including the accuracy check), good condition inspection, focusing on the fault location and easy to master, body and parts of the technical condition and abnormal phenomenon of information.  At the same time to formulate a check standard to determine the injection molding machine normal, abnormal, fault boundaries.
 4. To carry out failure analysis, training, machine maintenance man to master fault injection method.
 5. Failure to achieve record is the basis of injection molding machine fault management information, but also a failure analysis, processing of the original basis, records must be complete and correct.  Injection molding machine maintenance workers in the field inspection and troubleshooting, it should be in accordance with the "fault injection molding machine repair list" the contents of the fill, plant mechanic and submit monthly statistical analysis of injection molding machine management supervisor.
 6. Workshop injection molding machine maintenance workers failed to grasp the routine circumstances, should be brought together on "fault repair list" and the maintenance records.  Through the statistical failure data, sorting, analysis, calculation of all types of injection molding machine failure frequency, MTBF period of a single fault injection molding machine dynamics and key reasons for failure to find fault occurrence, in order to highlight key points to take countermeasures, fault information and analyzed data will be fed back to the planning department to arrange for repairs or improvements to the prevention program, you can also modify the regular inspection intervals as a check based on the content and standards.
 According to statistics collated data, statistical analysis can draw diagrams, such as a single statistical analysis of dynamic fault injection molding machine is the maintenance team on the fault table, and other effective methods for visual management, both for management and maintenance workers to grasp the various types of injection the case of machine failure, but also in determining when maintenance measures have a clear target.
 7. The daily tour by maintenance workers check and check the status of injection molding machine to obtain the status information and fault symptoms, and related records, analyze data, maintenance workers from the shop or repair of injection molding machines for all types of injection molding machine head of the existence of problems in a timely manner arrangements for routine maintenance, make full use of the production gap of time or holidays, so to prevent the former, in order to control and reduce failure.  Some signs of trouble, problems, routine maintenance can not afford, then back to the planning department for scheduling repairs.
 8. Development of fault information management flow chart.

 Fourth, injection molding machine fault law

 Failure to develop the maintenance of law on countermeasures, as well as to establish a scientific system of maintenance is very beneficial.  In the course of injection molding machine, the performance or status with the use of gradual decline over time.  Many will have some warning before a failure occurs, this is called latent faults, which can identify the physical parameters indicate that a functional failure is about to occur, functional fault injection molding machine that provides for the loss of performance standards.
 Injection molding machine failure rate variation with time, often called the bathtub curve.  Injection molding machine failure rate over time broadly divided into three stages: early failure period, occasional failure and depletion of the fault period.
 1. Early failure in the early failure of the injection molding machine on and started a high failure rate, but the failure rate over time, the rapid decline in the early failure of the mechanical products, also known as run-in period.  The length of this period, the product, system design and manufacturing quality varies.  This occurred during the failure, mainly by the design, manufacturing defects caused by or caused by improper use of the environment.
 2. Occasional failure of the injection molding machine into the occasional failure of the failure rate is about at the steady state, tend to be value.  During this period, failure is random.  Occasional failures in the period, the lowest failure rate of the injection molding machine, and stable.  . And therefore can be said that this is the best injection molding machine, said work on or period.  This section is called the effective life.
 Occasional failure of the fault, more the cause of the design, improper use and maintenance of the poor.  Therefore, by improving the design quality, improved use of management, strengthen monitoring diagnosis and maintenance, etc., can reduce the failure rate to the lowest level.
 3. Wear failure of the later use in injection molding machine, the failure rate begins to rise.  This is because the injection molding machine parts wear, fatigue, aging, corrosion caused.  If the inflection point that is wear and tear failure to overhaul the beginning, you can cost-effectively reduce the failure rate.
 Injection molding machine failure rate curve of the three stages of injection molding machines from truly reflect running, debugging, working to overhaul or scrap the variation of failure rate, strengthen the daily management and injection molding machine maintenance, occasional failure to extend the period.  Accurately identify the inflection point, to avoid excessive expansion of the scope of repair or repairs, to get the best returns on investment.

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