![<?echo $_SERVER['SERVER_NAME'];?>](/template/twentyseventeen/skin/images/header.jpg)
Since 1990, the author has introduced CNC machining equipment from abroad, most of which use Siemens CNC systems. The Siemens CNC systems still in use include 3TT system, 3M system, 805 system, 810T/M system, 840C system, 810D system, 840D system and 840D SL system.
These CNC systems are actually computer control systems, including software and hardware. Sometimes the software has problems or the machine data and parameter confusion will cause the CNC system to work abnormally. These faults can be eliminated by simply downloading the software backup or correcting the machine data and parameters. Here are a few examples of actual fault repairs.
Fault 1, a CNC ball milling machine system can not start
CNC system: Siemens 3TT system
Symptom: When this machine is powered on, the system can't start.
Fault Analysis: When starting the system, observe that the alarm light on the system operation panel is on, but the screen is not displayed. Check the numerical control device and find that the red alarm light on the CPU module of the PLC is on, indicating that there is no problem with the system power supply, and the system startup program may not be executed due to accidental factors or interference.
Troubleshooting: Put the “Run /Stop†toggle switch (Fig. 1) of the CPU module of the PLC in the “Stop†position, press the “Reset†button while the system is powered on, and then toggle “Run / Stopâ€. The switch is dialed from the “Stop†position to the “Run†position, then dials back to the “Stop†position, and then dials to the “Run†position. At this time, the PLC running light “Run†lights up, the system screen resumes display, and the system also It works fine.
Figure 1 Picture of buttons and indicators on the Siemens 3 system 130W/B CPU module
Fault 2, a CNC cylindrical grinding machine system crashes
CNC system: Siemens 805 system
Symptom: After the machine is started up, the system displays the basic screen, but no operation can be performed. Fault analysis and inspection: Through the analysis of the fault phenomenon, it is felt that the system has a crash. If it is a software cause, you can recover the system by forcibly starting it.
The Siemens 805 system is forced to start: there is a 16-speed rotation in the lower left corner of the system board, as shown in Figure 2, where 0 is the normal working mode of the system and 2 is the initialization mode. In the case of system power failure, the switch is set from position 0 to position 2, and then the system is powered on. At this time, the initialization mode is entered as long as the system has no hardware failure.
Figure 2 Siemens 805 system startup status setting switch and status indicator picture
Troubleshooting: After the system is forced to start, check that the system data is not lost. At this time, the shutdown system is powered off, and the rotary switch is turned from position 2 back to position 0. Then the system is powered on and the system resumes normal operation.
Fault 3, a CNC internal grinding machine boot system screen black screen
CNC system: Siemens 810T system
Symptom: After the machine has been deactivated for a period of time, the system does not display when it is turned on.
Fault analysis and inspection: Observe the startup process of the system, find that the alarm light on the panel is on, and the system alarm is displayed, so the system data is suspected to be lost. To do this, the system is first forced to start. The Siemens 810T/M system is forced to start as follows: Restart the system and press and hold the diagnostic “eye†button on the panel. If the system is dead or black due to a software problem, the system will enter the initialization screen. Forced start of this machine, the system enters the initialization screen, but the German text is displayed, indicating that the system data is lost and needs to be reinstalled. At this time, the screen displays alarm No. 1, indicating that the system backup battery is low. Checking the system backup lithium battery and found that the voltage is somewhat low.
Troubleshooting: First replace the system backup battery, then download the machine data and related files, then power off for a few minutes, reboot, the machine resumes normal operation.
Fault 4, a CNC ballistic grinder can not enter the Siemens operation
Interface CNC system: Siemens 840D system
Fault phenomenon: When this machine starts up the system, the error alarm interface shown in Figure 3 appears.
Fault analysis and inspection: The MMC of the numerical control system of this machine adopts PCU50. 1, PCU50. 1 It is actually an industrial computer, which is the host computer of the CNC system, with a hard disk, using the Widows XP operating system. In order to observe the fault phenomenon, restart after a few minutes of shutdown, then observe the system screen and find that when the Windows system boots and enters the Siemens software, the system displays the error alarm interface as shown in Figure 3, and no longer continues to run downward. Analysis error message: Application error (APP Er-ror) information is "Cannot open log file"; system error (System Error) information is "The volume does not communicate a recognized file system" Does not contain an identifiable file system). From the analysis of these information, it is considered that the cause of the obstacle should be PCU50. 1 Some files on the hard disk are missing, which is a problem in the software system.
Troubleshooting: In order to restore the system as soon as possible, the PCU50. 1 hard drive is removed (in fact, it can not be connected to the PC through the network cable for recovery, but the process is too cumbersome), the hard disk is installed to the mobile hard disk box to connect to the office PC, and the GHOST software will be used to backup the entire backup file in advance. Restore to the hard disk, then reinstall the hard disk to the PCU, then power on, the system resumes normal operation.
The CNC system using MMC (PCU) should do a good job of GHOST hard disk backup. Due to the poor environment of the machine and production workshop, the system hard disk is relatively easy to fail. When the system hard disk fails, the system program and data are restored to the new hard disk with the entire disk backup file to quickly eliminate the system failure.
Figure 3 Siemens 840D system error display picture
Fault 5, a CNC external cylindrical grinding machine starts alarm "2000PLC sign —— of —— life monitoring", "810004 Stop / abort event, error analysis via STEP7 re-quired" (stop, abnormal stop) Event, need to be analyzed by STEP7), indicating a problem with the system PLC system
CNC system: Siemens 810D system.
Fault analysis and inspection: When the fault occurs, check the CCU module and find that the digital display shows “6†(as shown in Figure 4). It is also normal, but the SF alarm light of the NC part is on, indicating that there is a fault alarm; the PLC side PS alarm light is on. Indicates that the PLC is stopped; the PF alarm light is on to indicate PLC alarm.
Based on the analysis of these phenomena, it is first suspected that there is a problem with the PLC program, that is, a software problem has occurred. Trouble-shooting: Because it only generates alarms on the PLC side, first perform a total clear operation on the PLC system, then download the PLC series backup file, shut down for a few minutes, and the system will resume normal operation immediately.
Figure 4 Siemens 810D system CCU3.4 module indicator display picture
Fault 6, a special CNC ballistic grinding machine has failed, the processing data can not be modified
CNC system: Siemens 840D system.
Fault analysis and inspection: Observe the fault phenomenon. Figure 5 is one of the system grinding parameter display screens. The data part of the two parameters becomes the ##, which cannot be changed, and the parameters with numerical values ​​cannot be modified. According to the machine operator's operation, in the working process of the machine tool, there have been machine operation, but only after machining several workpieces, the grinding data is modified, and the data is not modified.
Figure 5 grinding parameter modification screen
Based on the analysis of these phenomena, it is suspected that some of the machine data in the NCU has changed, thus causing confusion in the CNC system software. In order to eliminate this fault, the memory of the NC and PLC should be totaled before the series backup file is re-downloaded. In order to prevent this, although there has been a series of backups before, but still do a new series of backups, NC series backup process is very normal, but the PLC backup operation is completed very quickly, check the file found that the number of file bytes is wrong, PLC series The backup file has only 3 072 bytes, while the previous backup has 222 208 bytes, so it is suspected that the PLC program or bed data has been garbled or lost.
Trouble-shooting: First remove the NCU module and check that there is a lot of sludge in the cooling fan tuyere. So clean the NCU module first, then install it on the system, power on, and perform the total clear operation on the NC and PLC systems. Download the normal series. After backing up the file and then running the machining program, the machine resumes its normal function.
The serial backup file of the Siemens 810D/840D system is very important. When the NCU module is replaced or the NCU is abnormal, you need to download the series backup file recovery system. Therefore, the machine should be backed up regularly for NC and PLC when it is used normally after acceptance, so that the software system can be restored as soon as possible when there is a problem with the NCU module.
In addition, some CNC machine tool faults can be eliminated by adjusting the machine data of the CNC system. It is the software of the CNC system to solve the machine tool problem, and it is also a unique method for fault diagnosis of CNC machine tools. Below is an actual maintenance example.
Fault 7, there is a deviation in the position of a CNC lathe robot
CNC system: Siemens 840C system.
Fault phenomenon: After the machine turns on the reference point of each axis, it finds that the loading robot has a positional deviation from the center card.
Fault analysis and inspection: The robot of this machine is driven by the Q axis of the linear axis. The Q axis is driven by the servo motor and the incremental encoder is used as the position feedback component.
Figure 6 Siemens 840D system drive machine data screen
According to the working principle of the machine tool, after the Q axis returns to the reference point, the Q-axis loading robot stops at the center of the fixture. When working, the loading robot grabs the workpiece and stops at this position. The spindle clamp moves down vertically above the workpiece to reach The position of the workpiece grasps and clamps the workpiece, and at the same time the robot loosens the spindle, and the spindle clamp drives the workpiece to the machining position for processing.
In the event of a failure, the loading robot and the spindle chuck center have a deviation of about 7 - 8 mm visually. If the spindle clamp is lowered to grasp the workpiece, it will hit the workpiece.
Repeated Q-axis reference point operation, found that the position of the robot does not change, the analysis may cause the robot's reference point to change due to mechanical reasons.
Fault handling: In order to correct the position of the manipulator, the position compensation data of the Q-axis reference point can be modified, and the Q-axis reference point compensation machine data MD2442 can be called up. The original value is 77 mm. After several adjustments, it is modified to 88. At 1 mm, the deviation is corrected.
Fault 8, an NC quenching machine has an alarm "25080 AxisAZ2 positioningmonitoring" when executing the machining program (axis AZ2 position monitoring)
CNC system: Siemens 840D system.
Fault phenomenon: In order to observe the fault phenomenon, press the system reset button to reset the fault alarm, and then restart the machining program. It is found that the noise is very loud when the AZ2 axis moves, and then the 25080 alarm occurs, and the program is aborted.
Fault analysis and inspection: First check the AZ2 shaft slide and ball screw, but no mechanical problems were found. Because this is a new machine that has just been put into use, it is suspected that the mechanical characteristics of the AZ2 shaft change after a period of running-in. The mechanical inertia becomes smaller, causing the servo system to oscillate and generate noise, and the oscillation is too large and the 25080 alarm occurs. Therefore, in order to solve the problem, the gain machine data of the servo axis should be adjusted.
Digital Air Fryer,Best Digital Air Fryer,Digital Oil Less Fryer,Electric Digital Air Fryer
Ningbo ATAP Electric Appliance Co.,Ltd , https://www.atap-airfryer.com