Analysis and Treatment of Common Faults of Four-position Electric Tool Holder in Machining Center
In the field of modern mechanical processing, the application of numerical control skills and machining centers is of milestone significance. They excellently solve the automatic processing problems of medium and small batch parts with complex shapes and high consistency requirements. This breakthrough not only significantly improves production efficiency, pushes the processing accuracy to a new height, but also greatly reduces the labor intensity of workers and effectively shortens the production preparation cycle. However, like any complex mechanical equipment, numerical control machines will inevitably encounter various faults during use, which makes fault repair a key challenge that numerical control machine users must face.
On the one hand, the after-sales service provided by companies that sell numerical control machines often cannot be guaranteed in time, which may be caused by various factors such as distance and personnel arrangement. On the other hand, if users themselves can master some maintenance skills, then when a fault occurs, they can quickly determine the location of the fault, thereby greatly shortening the maintenance time and allowing the equipment to resume normal operation as soon as possible. In daily numerical control machine faults, various types of faults such as tool holder type, spindle type, thread processing type, system display type, drive type, communication type, etc. are common. Among them, tool holder faults account for a considerable proportion in overall faults. In view of this, as a machining center manufacturer, we will conduct a detailed classification and introduction of various common faults of the four-position electric tool holder in daily work and provide corresponding treatment methods, in order to provide useful references for the majority of users.
I. Fault analysis and countermeasure strategy for the electric tool holder of the machining center not being locked tightly
(一) Fault causes and detailed analysis
(一) Fault causes and detailed analysis
- The position of the signal transmitter disk is not aligned correctly.
The signal transmitter disk plays a crucial role in the operation of the electric tool holder. It determines the position information of the tool holder through the interaction between the Hall element and the magnetic steel. When the position of the signal transmitter disk is deviated, the Hall element cannot accurately align with the magnetic steel, which leads to inaccurate signals received by the tool holder control system and then affects the locking function of the tool holder. This deviation may be caused by vibration during equipment installation and transportation or by the slight displacement of components after long-term use. - The system reverse locking time is not long enough.
There are specific parameter settings for the tool holder reverse locking time in the numerical control system. If this parameter is set improperly, for example, the setting time is too short, when the tool holder performs the locking action, the motor may not have enough time to complete the complete locking of the mechanical structure. This may be caused by incorrect system initialization settings, inadvertent modification of parameters, or compatibility issues between the new tool holder and the old system. - Mechanical locking mechanism failure.
The mechanical locking mechanism is the key physical structure to ensure the stable locking of the tool holder. During long-term use, mechanical components may have problems such as wear and deformation. For example, the positioning pin may be broken due to frequent stress, or the gap between mechanical transmission components increases, resulting in the inability to effectively transmit the locking force. These problems will directly lead to the inability of the tool holder to lock normally, affecting the processing accuracy and safety.
(二) Detailed explanation of treatment methods
- Adjustment of signal transmitter disk position.
When it is found that there is a problem with the position of the signal transmitter disk, it is necessary to carefully open the top cover of the tool holder. During the operation, pay attention to protecting the internal circuits and other components to avoid secondary damage. When rotating the signal transmitter disk, appropriate tools should be used and the position should be adjusted with slow and accurate movements. The goal of adjustment is to make the Hall element of the tool holder accurately align with the magnetic steel and ensure that the tool position can accurately stop at the corresponding position. This process may require repeated debugging. At the same time, some detection tools can be used to verify the adjustment effect, such as using a Hall element detection instrument to detect the accuracy of the signal. - Adjustment of system reverse locking time parameter.
For the problem of insufficient system reverse locking time, it is necessary to enter the parameter setting interface of the numerical control system. Different numerical control systems may have different operation methods and parameter locations, but generally, the relevant tool holder reverse locking time parameters can be found in the system’s maintenance mode or parameter management menu. According to the model of the tool holder and the actual usage situation, adjust the reverse locking time parameter to an appropriate value. For a new tool holder, usually a reverse locking time t = 1.2s can meet the requirements. After adjusting the parameters, perform multiple tests to ensure that the tool holder can be reliably locked under different working conditions. - Maintenance of mechanical locking mechanism.
When it is suspected that there is a fault in the mechanical locking mechanism, a more comprehensive disassembly of the tool holder is required. During the disassembly process, follow the correct steps and mark and properly store each disassembled component. When adjusting the mechanical structure, carefully check the wear condition of each component, such as the tooth surface wear of gears and the thread wear of lead screws. For the problems found, repair or replace the damaged components in time. At the same time, pay special attention to the state of the positioning pin. If it is found that the positioning pin is broken, select an appropriate material and specification for replacement and ensure that the installation position is accurate. After reassembling the tool holder, conduct a comprehensive debugging to check whether the locking function of the tool holder has returned to normal.
II. Fault analysis and solution for a certain tool position of the electric tool holder of the machining center continuously rotating while other tool positions can rotate
(一) In-depth analysis of fault causes
(一) In-depth analysis of fault causes
- The Hall element of this tool position is damaged.
The Hall element is a key sensor for detecting tool position signals. When the Hall element of a certain tool position is damaged, it will not be able to accurately feed back the information of this tool position to the system. In this case, when the system issues an instruction to rotate this tool position, the tool holder will continue to rotate because the correct in-position signal cannot be received. This damage may be caused by quality problems of the element itself, aging during long-term use, being subjected to excessive voltage shocks, or being affected by external environmental factors such as temperature, humidity, and dust. - The signal line of this tool position is open-circuited, resulting in the system being unable to detect the in-position signal.
The signal line acts as a bridge for information transmission between the tool holder and the numerical control system. If the signal line of a certain tool position is open-circuited, the system will not be able to obtain the status information of this tool position. The open circuit of the signal line may be caused by internal wire breakage due to long-term bending and stretching, or damage due to accidental external force extrusion and pulling during equipment installation and maintenance. It may also be caused by loose connections and oxidation at the joints. - There is a problem with the tool position signal receiving circuit of the system.
The tool position signal receiving circuit inside the numerical control system is responsible for processing the signals coming from the tool holder. If this circuit fails, even if the Hall element and signal line on the tool holder are normal, the system cannot correctly identify the tool position signal. This circuit fault may be caused by damage to circuit components, loose solder joints, moisture on the circuit board, or electromagnetic interference.
(二) Targeted treatment methods
- Hall element fault detection and replacement.
First, determine which tool position causes the tool holder to rotate continuously. Then input an instruction on the numerical control system to rotate this tool position and use a multimeter to measure whether there is a voltage change between the signal contact of this tool position and the +24V contact. If there is no voltage change, it can be determined that the Hall element of this tool position is damaged. At this time, you can choose to replace the entire signal transmitter disk or only replace the Hall element. When replacing, ensure that the new element is consistent with the model and parameters of the original element, and the installation position is accurate. After installation, perform another test to verify the normal operation of the tool holder. - Signal line inspection and repair.
For suspected signal line open circuit, carefully check the connection between the signal of this tool position and the system. Starting from the tool holder end, along the direction of the signal line, check for obvious damages and breaks. For the joints, check for looseness and oxidation. If an open circuit point is found, it can be repaired by welding or replacing the signal line with a new one. After repair, perform insulation treatment on the line to avoid short circuit problems. At the same time, perform signal transmission tests on the repaired signal line to ensure that the signal can be accurately transmitted between the tool holder and the system. - Fault handling of system tool position signal receiving circuit.
When it is confirmed that there is no problem with the Hall element and signal line of this tool position, it is necessary to consider the fault of the system’s tool position signal receiving circuit. In this case, it may be necessary to check the motherboard of the numerical control system. If possible, professional circuit board detection equipment can be used to find the fault point. If the specific fault point cannot be determined, on the premise of backing up the system data, the motherboard can be replaced. After replacing the motherboard, perform system settings and debugging again to ensure that the tool holder can rotate and position normally at each tool position.
During the use of numerical control machines, although the faults of the four-position electric tool holder are complex and diverse, through careful observation of fault phenomena, in-depth analysis of fault causes, and adoption of correct treatment methods, we can effectively solve these problems, ensure the normal operation of machining centers, improve production efficiency, and reduce losses caused by equipment failures. At the same time, for numerical control machine users and maintenance personnel, continuously accumulating fault handling experience and strengthening the learning of equipment principles and maintenance technologies are the keys to dealing with various fault challenges. Only in this way can we better exert the advantages of equipment in the field of numerical control processing and provide strong support for the development of the mechanical processing industry.