According to the location of the fault of CNC machine tools

First, the host of the fault: high-speed machining center of the host generally refers to the composition of high-speed machining center machinery, lubrication, cooling, chip removal, hydraulic, pneumatic and protective parts; host common faults are:

1, due to rails, spindles and other moving parts of the interference, excessive friction and other causes of failure

2, due to mechanical parts damage, bad connection and other causes of failure, and so on.

Host failure mainly for the transmission noise, poor processing accuracy, running resistance, mechanical parts action is not carried out, mechanical parts damage and so on. Poor lubrication, hydraulic, pneumatic system, pipeline blockage and poor sealing, is a common cause of failure of the host. High-speed machining center of the regular maintenance, maintenance. Control and eradication of the "three leakage" phenomenon is to reduce the host part of the important measures of failure.

3, due to mechanical parts installation, commissioning, improper operation and other reasons caused by mechanical transmission failure Second, the electrical control system is faulty from the type of components used. According to the usual habit, electrical control system failure is usually divided into "weak" fault and "strong power" fault two categories, "weak" part of the control system is to electronic components, integrated circuit-based control part. High-speed machining center of the weak part, including CNC, PLC, MDI / C RT and servo drive unit, lost to the output unit.

"Weak" failure and hardware failure and software failure of the points. Hardware failure refers to the above-mentioned parts of the integrated circuit chip, discrete electronic components, connectors and external connection components such as the failure. Software failure refers to the hardware in the normal circumstances of the action out of germanium, data loss and other failures, there are common. Processing program error, system program and parameter changes or loss, computer operation error and so on.

"Strong" refers to the control system in the main circuit or high voltage, high-power circuit in the relay, contactors, switches, fuses, power transformers, motors, electromagnets, travel switches and other electrical components and its composition Control circuit. This part of the fault although the maintenance, diagnosis is more convenient, but because of its high pressure, high current working state, the probability of failure is higher than the "weak" part. Must pay attention to the maintenance staff.

Third, according to the nature of the classification of failure

1, deterministic fault Deterministic failure refers to the control system host hardware damage or as long as meet certain conditions, high-speed machining center will inevitably occur failure. This type of fault phenomenon in the high-speed machining center is the most common, but because it has a certain law, it also brought convenience to the maintenance

Deterministic failure is irreversible, the failure occurs, if not for its maintenance processing, the machine will not automatically return to normal. But as long as the root cause of the failure to find out, after the completion of maintenance machine can immediately return to normal. Proper use and careful maintenance is an important measure to prevent or avoid malfunctions.

2, random failure random failure refers to the high-speed machining center in the course of the accident occurred in the fault of such failures occur more subtle, it is difficult to find its regularity, it is often referred to as "soft fault", random failure The fault analysis is often related to the installation quality of components, the setting of parameters, the quality of components, the imperfect design of the software, the impact of the working environment and many other factors.

Random failure is recoverable, after the failure, through the restart and other measures, the machine can usually return to normal, but in the course of the operation, and the same failure may occur.

Strengthen the maintenance of CNC system checks to ensure that the electrical box of the sealed, reliable installation, connection, the correct grounding and shielding is to reduce the occurrence of such failures important measures.

4, according to the failure of the instructions in the form of classification

There are reported with the fault display High-speed machining center fault display can be divided into indicator display and display display two cases:

Indicator indicator Alarm indicator The alarm is displayed by the status indicator on the unit of the control system (usually composed of LED LED or small indicator light). According to the status indicator of the numerical control system, even in the display failure, can still be roughly analyzed to determine the location and nature of the fault occurred, therefore. In the maintenance, troubleshooting process should be carefully check the status of these status lights.

The display shows an alarm. The display shows that the alarm is an alarm that can display the alarm number and alarm information through the CNC display. As the CNC system generally have a strong self-diagnostic function, if the system's diagnostic software and display circuit work properly, once the system fails, you can display on the display in the form of alarm and text display fault information. CNC system can display the alarm as few as dozens, as many as thousands, it is an important diagnostic information.

In the display display alarm, can be divided into NC alarm and PLC reported two categories. The former for the NC manufacturers set the drop display. It can be based on the system's "maintenance manual" to determine the possible causes of the failure. The latter is set by the high-speed machining center manufacturers PLC alarm information text, is the machine side of the drop display. It can control the machine tool manufacturer provided by the "machine maintenance manual" in the relevant content. Determine the cause of the failure.

No alarm display failure This type of failure occurs. Machine and system are no alarm display, the diagnosis and diagnosis is usually more difficult. Need to be carefully and carefully analyzed to confirm. Especially for some of the early CNC system, because the system itself is not strong diagnostic function, or no PLC alarm message text, there is no alarm display failure wish more.

For no alarm display failure, usually specific analysis of specific circumstances, according to changes before and after the failure. Analysis and judgment, principle analysis and PLC program analysis method is to solve the main method of no alarm display failure.

According to the cause of the fault classification

High-speed machining center itself failure This type of failure is due to high-speed machining center itself caused by the reasons, and external use of environmental conditions have nothing to do. Many of the faults that occur at high-speed machining centers are such failures.

High Speed Machining Center External Fault This type of failure is caused by external causes. Power supply voltage is too low, too high, excessive fluctuations: the power phase sequence is not correct or three-phase input voltage imbalance; ambient temperature is too high: harmful gases, moisture, dust granted: external vibration and interference are caused by failure the reason.

In addition, human factors are also caused by high-speed machining center failure of one of the external reasons, according to the statistics, the first use of high-speed machining centers or by unskilled workers to operate high-speed machining center, in the first year of use, improper operation caused by the external Failure to account for more than one-third of the total machine failure.

In addition to the above common fault classification methods, there are many other different classification methods. Such as: whether the failure occurred when the destruction can be divided into destructive and non-destructive failure of two. According to the failure occurred with the need to repair the specific functional parts. Can be divided into numerical control device failure, feed servo system failure, spindle drive system failure, white change tool system failure, etc., this classification method commonly used in maintenance.