On Product
CNC machine common electric fault diagnosis and elimination method

1.1 CNC subgrade electrical installations Troubleshooting

Electrical equipment malfunction part CNC machine is mainly a hardware failure, hardware failure which is: the control system of a bad or damaged components, no power supply, etc., this failure must be replaced after the repair of damage to the device or troubleshooting.

1.2 Failure Analysis  programmable controller CNC machine tools

CNC machine tools, programmable logic controller, which is part of the PLC controller failure is divided into: (1) software failure: CNC machine tools, including the user program, if the user program fails, the CNC machine tool is running a number of machine failure occurs without an alarm, So good to be prepared PLC user program. (2) Hardware failure: that is, the problem of failure in the PLC caused by input and output modules. For individual input and output ports fails, you can modify the PLC program, you can use the interface to the backup interface to replace faulty.

1.3 Failure analysis of CNC machine tool servo system

CNC machine tool servo control system is the highest part of the NC machine tool failure rate. Servo control system can be divided into DC servo control unit, DC permanent magnet motor and AC servo control unit, AC servo motor has two parts, both of which have their own advantages and disadvantages. Servo system failures are generally due to the servo control unit, servo motors, speed measurement equipment, encoders and other problems caused to be analyzed separately for each unit.

1.4 Failure Analysis display

Under normal circumstances, CNC machine tools display errors of performance: system software error, which can cause confusion displayed by the system or not normal or not displayed, if the machine's power failure or system board failure, then will lead to system normal display. Wherein the display system failure is caused by the system itself is not properly monitor the most important reason, therefore, if the system does not display properly, we must first distinguish the main cause of this phenomenon.
CNC machine tools can be divided is not displayed properly display and the display is not completely normal in both cases. While other parts of the power supply and the system is normal, because no display system, under normal circumstances due to hardware causes, and display confusion or display is not normal, is generally caused due to system software. In addition, systems, caused by different reasons, which have to be analyzed according to the actual situation.

1.5 Control element failure analysis, test switch

CNC machine tool commonly used control elements have hydraulic components, pneumatic components, electrical actuators, mechanical devices, detection switch, sensing elements are: detection switch, machine control these common elements, the detection switch caused by a variety of failures due to poor contact more, this fault is easy to solve, but must cooperate with the inspection instruments.

2 CNC machine tools Common Electrical Troubleshooting Methods

CNC machine tools troubleshooting many ways, can be divided into the following categories:

2.1 visual inspection method

 This is the fault analysis method must be used at the beginning, is the use of sensory examination.
   (1) Q. Namely the fault site staff asked in detail about the process of generating a fault, the fault representation and the consequences of failure, and the entire process of analysis and judgment may have to ask several times.
   (2) See. The overall view is part of the work status of each machine in the normal state (for example, the position of each axis, spindle status, magazine, robot location, etc.), each electronic control device (such as a control system, temperature control equipment, lubrication equipment, etc.) without alarm indication partial view with or without insurance burn burnt, charred components, cracking, cable loss, each operating element position is correct or not and so on.
  (3) touch. Under the conditions of the machine power off by touching the main circuit board installation status, the status of each connector plug seat, all power and signal conductors (such as servo and motor contactor wiring) connection status to detect possible failure the reason.
   (4) again. This means that in order to check for smoke, spark, any abnormal sound, smell and touch the presence or absence of overheating of the motor and components and powered off immediately once the analysis found.

2.2 Instrument Inspection Act

Instrument inspection method is the use of conventional electrical instruments for each group AC and DC power supply voltage and DC and pulse signals related measure, which could find fault. For example, check the power supply situation with a multimeter, and the board is set for some measurements related to the signal state of the measuring point, with the oscilloscope amplitude, phase or whether the relevant heartbeat look with PLC programming PLC program Fault location and reason and so on.

2.3 and alarm indication signal analysis

   (1) refers to the hardware alarm. This refers to a variety of status and fault indicators on the various electronic and electrical equipment including CNC system, servo systems, including combined indicator status and corresponding functional description can be informed of the reasons for the content and fault indication and troubleshooting.
   (2) software alarm indication. As mentioned earlier system software, PLC program and processing program failures are usually equipped with alarm display, alarm control number corresponding diagnostic manual based displays can learn possible causes and troubleshooting methods.

2.4 Interface Status Examination

The more modern CNC system PLC integrated in them, and places a series of interface signals in the form of mutual communication between CNC and PLC connection. Some of the fault is with the interface signal errors or loss related to, some of these interface signals in the corresponding interface board and the input / output panel indicator lights, and some simple operations can be displayed on the CRT screen, and all interfaces signals can be called up using the PLC programmer. Maintenance, require maintenance personnel familiar with the tools necessary to interface signals, but also familiar with PLC programming applications.

2.5 Parameter Adjustment Act

CNC systems have set a number of parameters that can be modified to suit the requirements of different machines, different working conditions. These parameters not only make all electrical systems to match specific machine, but the machine is to make the best of the features necessary to achieve. Therefore, any change (in particular the analog parameter) parameter is not allowed even lost; and changes in mechanical or electrical properties caused by operating the machine changes its optimal state. Such failures need to re-adjust one or more parameters associated with only excluded. This method requires the maintenance staff is very high, not only to the specific parameters of the system is mainly very understanding, both familiar and its role, and have a wealth of experience in the electrical commissioning.

2.6 Spare parts replacement method

When the failure to focus on a printed circuit board, due to expanding circuit integration and make failure more difficult to implement in a given region and a component, in order to reduce downtime, spare parts under the same conditions as may be The spare parts replaced, and then check the repair faults board. Replacement parts board should pay attention to the following issues:
   (1) replacement of any spare parts must be carried out in case of power outages.
   (2) the replacement of spare parts to be recorded under the original panel switch position and set state, and the new board make the same settings, or will cause the alarm was not working.
   (3) some of the printed circuit board needs replacement after replacement of certain operations carried out to establish a complete software and wherein the parameter. It needs to read the appropriate board's instructions carefully.
   (4) Some of the printed circuit board can not be easily pulled out of, such as a plate comprising a working memory, or the backup battery plate, it will lose useful parameter or program. Must also comply with the relevant instructions must be replaced.
    In view of the above conditions after, be sure to read the relevant information carefully before you pull out the old board replacement board, understand the requirements and procedures before you start, so as not to cause more trouble.

2.7 Cross-conversion law

When they find fault board or board but can not determine if the absence of spare parts case, the system of two identical or compatible board swap paint disperser dispersing machine inspection speed disperser laboratory dispersing machine vacuum dispersion dispersed movements machine high viscosity dispersion machine laboratory dispersing machine double planetary mixer, double planetary mixer multifunctional epoxy resin mixer mixer mixer cell battery pulp slurry mixer, not only hardware wiring is correct exchange, but also to a corresponding set of parameter exchange must be well thought out in advance, good software design, hardware exchange programs, exchange of accurate re-examination.

2.8 special treatment method

Today's CNC system in which more and more content-rich software, system software, machine tool maker software, and even the user's own software, due to some problems in the design of software logic inevitably, will make some fault state not able to analyze, for example, the phenomenon of death. For this failure phenomenon can take special measures to deal with, such as machine power, pause and then boot, sometimes it may be the failure to eliminate. Its laws or other effective methods maintenance personnel can explore in their own long-term practice.

3 Conclusion

CNC machine tool production is the key equipment, regardless of price or the price of the product equipment is very expensive, the service life of the machine tool business is very important, therefore, machine repair, maintenance, failure analysis and fault after processing becomes very important. Although a wide range of CNC machine tools, fault ever-changing, but the fault analysis and repair methods are essentially the same. Once identified the cause of the fault will almost equal excluded. Therefore master fault analysis and diagnosis method is very important.

Online Inquiry

Contact US

Taian Hiscience Machinery Co.,Ltd.
Address:No.71, Chuangye street, Taian City, Shandong province
Phone:+86 0538 8095612
Mobile:+86 18562315050
Email: franklee@tahience.com
Copyright 2014-2019 Taian Hiscience Machinery Co.,Ltd. All rights reserved.