Common Fault Diagnosis and Maintenance of CNC Machining Center Machine Tool

With the popularization of the application of CNC machine tools, the application of CNC machine tools is becoming wider and wider. To enhance the utilization value of CNC machine tools, we must pay attention to the repair and maintenance of CNC machine tools. In the use of CNC machining center machine tools, common faults should be combined with fault diagnosis and maintenance to ensure the normal operation of CNC machine tools.

The failure of CNC machining center machine tools is relatively common. Once a failure occurs, it will directly affect the operating quality of the CNC machine tool, and then cause the loss of parts and components, and affect the processing efficiency and quality. Therefore, it is necessary to strengthen the diagnosis of its common faults, adopt a fast emergency response mechanism, and carry out repairs in a timely manner to effectively improve the processing quality and efficiency.

1. The composition of CNC machining center machine tools

CNC machine tools are generally composed of input and output devices, numerical control devices (or numerical control units), spindle units, servo units, driving devices (or actuators), programmable controllers PLC, electrical control devices, auxiliary devices, and measuring devices. In the CNC machining center machine tool, the CNC device is the core of the CNC system, which is directly related to the overall operation quality of the CNC machine tool. Therefore, in the application process of CNC machining center machine tools, the diagnosis and inspection of this part of the device should be emphasized, the loopholes and defects in the system should be discovered in time, and the targeted maintenance plan should be adopted.

In the practical application of CNC machining center machine tools, the input and output device is the transmission terminal, through which the operator can judge the processing information, and can be used for the preparation, storage, printing and display of the part processing program or the processing information of the machine tool. Display etc. The CNC machining center machine tool is a comprehensive system that contains diversified devices. Only when different devices interact and interrelate can they effectively realize the functions of the system and truly enhance the integrity of the system. But because of this, in the actual application process of CNC machining center machine tools, various failures are often prone to occur, resulting in uneven quality of parts and components, which seriously affects the overall operating efficiency of CNC machining center machine tools.

2. Common fault types of CNC machine tools

The common faults of CNC machining center machine tools mainly include the following.

2.1 System failure

In the application process of CNC machining center machine tools, system failure is a relatively common type of failure. The system failure of CNC machine tools is mainly due to the influence of its own conditions or related parts exceeding the standard of use. For example, there is a leakage problem in the cooling system. During long-term use, the cooling system has a relatively serious leakage under a large load and pressure, which makes the CNC machining center machine tool produce a relatively serious heating phenomenon in actual action. The system reacts slowly, and the processing accuracy is also reduced. Under more severe conditions, it is easy to cause the CNC machining center machine tool system to alarm or even automatically shut down for protection. For example, when different axes are moving, they may exceed the specified range. When the motion limit is exceeded, the CNC machining center machine tool will also have an overtravel alarm. Based on this, in the actual application process of CNC machining center machine tools, maintenance and management should be strengthened, various failures in the system should be discovered in time, scientific and effective measures should be taken to eliminate failures in time, and ensure the overall safety and reliability of the system.

2.2 Random failure

In the practical application process of CNC machining center machine tools, the occurrence of random failures is also relatively common. However, random failures may not occur as frequently as system failures, nor are they as inevitable as system failures. The former are accidental failures. Only under certain conditions can it happen. Therefore, in the application process of CNC machine tools, it is difficult to analyze and judge the causes of random failures in advance and do preventive work. The reason why random failures are prone to occur may be related to the setting of certain key parameters, the quality of the operating environment, or the operating procedures and skills of the operators. For example, connectors and connecting components are not locked due to negligence, relay contacts, and various switch sockets performance degradation, etc., may cause random failures of CNC machining center machine tools.

2.3 Alarm display failure

In the application process of CNC machining center machine tools, alarm display failures are also relatively common. CNC machine tools are composed of different software and hardware. If the software or hardware fails, an alarm will be displayed. All kinds of hardware equipment of CNC machine tools basically have automatic alarm devices. However, if the hardware equipment is abnormal, or exceeds the normal value specified for use, it will trigger the alarm equipment of the CNC machine tool hardware device, which will cause the warning light to light up. During the operation of the CNC machine tool, the software equipment will also give an alarm. For example, there is an error in the processing program of the numerical control system, or the setting of the system program and parameters is incorrect or missing, the calculation of the computer is wrong, and so on. Compared with other failures, this type of failure will give clear prompts and reminders to arouse the attention of the operator. When such a clear fault occurs in the application of CNC machine tools, you can perform targeted diagnosis and maintenance according to different alarm indicators to ensure the stable operation of the CNC machine tool system. In addition, during the operation of CNC machine tools, there is another type of fault that is difficult to diagnose. When the CNC machine tool has this kind of failure, no matter it is the software equipment or the hardware equipment inside the system, it may not show a clear indicator light. Once this type of failure occurs, the diagnosis is more difficult. In order to quickly determine the fault and quickly delineate the area where the fault occurs, the actual state of the system before and after the fault should be combined to make the judgment and quickly find the fault point.

3. Common fault diagnosis and maintenance of CNC machining center machine tools

When a CNC machine tool fails, maintenance personnel should quickly intervene to avoid the expansion of the fault and endanger the overall operation of the CNC machine tool. However, in the process of fault diagnosis, maintenance personnel should seek the cooperation and support of the operator, and understand the state of the CNC machining center before and after the failure through actual investigations, and then effectively determine the type and size of the failure of the CNC machine tool, using scientific and reasonable methods Maintenance measures for maintenance management. Taking several common failures as examples, we will scientifically discuss the troubleshooting methods of CNC machining center machine tools.

3.1 The tool is dropped when the spindle tool is exchanged with the tool in the tool magazine

In the practical application of CNC machining center machine tools, the occurrence of tool drop problems is relatively common. Once the phenomenon of tool drop occurs, it will seriously affect the efficiency of CNC machining. Analysis of the common causes of tool drop can be summarized in the following aspects: First, during the tool change process, the headstock did not return to the tool change position, and the tool change has been performed when there is still a certain distance from the tool change point, which will affect The quality of the tool change. At the same time, during the tool change process, the tool change point appeared abnormal, and the tool change point deviated from the specified position. During the operation, the manipulator did not reach the designated position, and the tool was pulled. In the actual use of CNC machining center machine tools, once such failures occur, corresponding measures must be taken. The scientific method is to re-select the position of the headstock and let it move again to ensure that it fits the tool change point. If necessary, you can also reset the tool change point inside the system.

3.2 The tool magazine does not rotate properly

In the application process of CNC machining center machine tools, the frequency of such failures is also relatively common. The common reasons for this kind of failure mainly include the following aspects, the failure of the motor, especially the position deviation may occur during the rotation. The performance problem of the hydraulic system, the oil circuit may not be smooth when the hydraulic system is used. Of course, it may also be due to the tool magazine itself, for example, the load of the tool magazine exceeds the actual capacity. Therefore, when dealing with such failures, we should combine the causes of the failures and adopt corresponding measures, focusing on screening the rotation of the motor. If it is found to be the cause of this, it should be adjusted in time, and if necessary, it can be replaced directly. If it is a hydraulic problem, it is necessary to focus on a comprehensive inspection of the system to ensure its overall operating status. If it is the tool magazine, check whether the tool is installed in compliance with the specification, and ensure the accuracy of the tool installation program and position.

3.3 Non-display failure of CNC machine tools

In the application process of the CNC machining center machine tool, especially in the debugging stage, there is no area to display the fault. At the same time, the system is running continuously, but the display is faulty. After restarting, the fault disappeared again. When such failures occur in CNC machine tools, maintenance personnel can make direct judgments through experience. Check the contact performance of various components to determine whether it is a fault due to poor contact. At the same time, check the display board. In the inspection process, manual mode can be used to perform fault diagnosis through inspection one by one.

3.4 Battery voltage drop failure

In the actual application of CNC machining center machine tools, there may also be battery voltage problems. If the battery voltage drops, the CNC machine tool will give a displayed alarm. When such a failure occurs, the maintenance personnel can quickly and accurately determine the cause and area of the failure through the alarm indicator. Once the CNC machining center machine has such a failure, the battery should be replaced in time. Some operators may forget or other subjective factors and forget to replace the battery. The consequence is that the memory content is lost. Therefore, in the application practice of CNC machining center machine tools, when there is an early warning of insufficient power and voltage, the battery should be replaced in time.