Method and system for spindle overload protection applied to numerical control machining

Abstract

The application relates to an axle overload protection method and system applied to numerical control machining, which comprises the following steps: acquiring an axle overload driving number and a set axle overload condition customized by a user; continuously reading axle current information in real time by adopting a time-sharing polling mode through a PLC; judging whether axle overload occurs according to the read axle current information based on the axle overload driving number and the axle overload condition; when the axle overload occurs, performing alarm processing and generating current equipment information text, and performing a lock machine or non-lock machine operation according to user setting; and when the alarm lock is performed, performing an alarm lock release operation according to an input password. The axle overload protection method provided by the application can realize real-time monitoring, accurate triggering, rapid locking and non-resetting.

Description

Technical Field

[0001] This invention relates to a method and system for shaft overload protection applied to CNC machining, belonging to the field of machine tool processing. Background Technology

[0002] In the field of machine tool processing, overload protection technology for key drive shafts such as spindles and feed axes is crucial for ensuring safe equipment operation and machining accuracy. During high-speed, high-precision machining, the spindle and feed axis systems must withstand complex dynamic loads, including cutting forces, inertial forces, and external impacts. When the torque, axial force, or radial force borne by the shaft system exceeds its rated load capacity, failure to take timely and effective protective measures may lead to elastic or plastic deformation of the mechanical structure, thereby affecting machining accuracy and even causing permanent damage to the equipment. Currently, most CNC machine tools adopt a built-in overload detection mechanism based on the servo drive system. When the load exceeds a preset threshold, the system triggers an overload alarm and takes emergency shutdown measures. However, this traditional overload protection method still has many limitations in practical applications.

[0003] First, existing overload protection technologies exhibit significant lag in response. Since overload alarms rely on real-time monitoring of internal system parameters, and alarm thresholds are typically set close to the mechanical structure's limits, the protection mechanism is only triggered when the load has reached a high level. This delayed response may result in the machine tool experiencing impact or deformation before the alarm, affecting machining quality. Second, existing overload protection systems lack precision, making it difficult to identify potential risks in their early stages. Because the system only issues an alarm when the load reaches its limit, the mechanical structure may have already undergone minor deformation. Long-term accumulation of this deformation leads to precision degradation and increased equipment maintenance costs. This is particularly problematic in the cemented carbide industry, where machining tools and products are expensive, easily resulting in substantial economic losses. Furthermore, existing overload alarm mechanisms lack effective fault tracing capabilities. When an overload alarm is triggered, operators typically can only perform a reset operation, unable to accurately obtain real-time data such as load change trends, force direction, and external interference factors. This makes fault diagnosis difficult, hindering the determination of whether the overload is caused by abnormal cutting parameters, tool wear, or mechanical collisions (such as machine crashes), thus reducing equipment maintainability and operational reliability. Therefore, although existing machine tool axis overload protection technologies can prevent serious accidents in terms of basic functions, they still have significant shortcomings in terms of response speed, protection accuracy, and fault tracing capabilities. Summary of the Invention

[0004] This invention provides a method and system for shaft overload protection in CNC machining, aiming to solve at least one of the technical problems existing in the prior art.

[0005] The technical solution of the present invention relates to a shaft overload protection method applied to CNC machining. The method according to the present invention includes the following steps:

[0006] S100: Obtain the user-defined shaft overload drive number and the set shaft overload conditions;

[0007] S200 uses a time-division polling method via PLC to continuously read shaft current information in real time;

[0008] S300: Based on the shaft overload drive number and the shaft overload condition, determine whether a shaft overload has occurred according to the read shaft current information; when a shaft overload occurs, perform alarm processing and generate current device information text, and perform a lock or unlock operation according to user settings; wherein, after performing alarm lock, perform alarm lock release operation according to the input password.

[0009] Furthermore, in step S200, a two-stage delay loop control method is used for periodic polling to obtain shaft current information in real time and quickly.

[0010] Furthermore, in step S200, reading the shaft current information includes the following steps:

[0011] S210. When the system's always-true status flag is true, proceed to the main logic flow.

[0012] S220. At the beginning of the process, if the polling status flag is false, start the first timer for a delay of N time units.

[0013] S230. When the first timer delay is completed, set the polling status flag to true;

[0014] S240. When the polling status flag is true, start the second timer; delay for M time units, and simultaneously collect shaft current information;

[0015] S250. When the second timer delay ends, the polling status flag is reset to false.

[0016] S260, repeat steps S210 to S250 until a stop processing command is received.

[0017] Furthermore, in step S100, the overload drive number of the shaft is defined using a counter, which includes the following steps:

[0018] S111, Start the driver number definition process through the normally open contact;

[0019] S112. When the polling status flag is detected to be true, execute the counter value comparison instruction to determine whether the current cumulative counter value is greater than or equal to the preset threshold K.

[0020] S113. When the condition is greater than or equal to the preset threshold K, a counter increment instruction is triggered to perform an accumulation operation on the counter, and the accumulation limit is set to K.

[0021] S114. During the counter accumulation operation, the corresponding axis drive number is dynamically generated based on the current value of the counter.

[0022] Further, in step S100, based on the definition of the axis drive parameters of any axis, the predefined drive parameter number and its corresponding configuration data are dynamically read by matching the values ​​of the status word, and the parameter number is written into the designated parameter storage area to complete the intelligent configuration of the drive parameters. This includes the following steps: when the status bit of the first data block is detected to be false and the current value of the counter is equal to the first preset value, the corresponding data transmission operation is performed according to the different values ​​of the status word of the second data block. The data transmission operation includes: when the status word is equal to the first preset value, the first preset parameter number is written into the designated byte of the target data block; when the status word is equal to the second preset value, the second preset parameter number is written into the corresponding position; when the status word is equal to the third preset value, the third preset parameter number is written into the corresponding position.

[0023] Furthermore, in the setting of the shaft overload condition in step S100, the shaft current exceeds the rated current by a certain percentage as the basis for judging shaft overload, according to the rated current standard of the motor.

[0024] Furthermore, the shaft overload alarm processing in step S300 includes the following steps:

[0025] S311. When the first data block error flag bit and the second data block running status bit are both true, check in turn whether the value in each axis status data register is equal to the preset error threshold; wherein, when the value of a certain axis status register is equal to the preset error threshold, the corresponding error status flag bit is set.

[0026] S312. Check if the abnormal status byte is not equal to 0. If the condition is met, activate the alarm output bit.

[0027] Furthermore, the alarm lock release operation in step S300 includes the following steps: based on the combination logic of the third data block reset signal and not the fourth data block lock flag, or the first data block abnormal flag bit, combined with the fifth data block enable signal, the abnormal status byte is finally reset to 0 to release the machine lock state.

[0028] The present invention also relates to a computer-readable storage medium having program instructions stored thereon, which, when executed by a processor, implement the above-described method.

[0029] The present invention also relates to an axis overload protection system for CNC machining, the system comprising a computer device including the aforementioned computer-readable storage medium.

[0030] The beneficial effects of this invention are as follows.

[0031] This invention relates to a control method and system for axis overload protection in CNC machining. When a machine tool is subjected to a collision, it can promptly trigger an alarm and effectively reduce damage. By directly monitoring the real-time load of the axis, it effectively solves the lag and error problems caused by indirect monitoring, improving the real-time performance and accuracy of detection and protection, and effectively preventing damage. This invention uses a CNC system function development approach to achieve axis overload protection locking. Protection is achieved through the cooperation between the PLC and NC, without requiring external hardware or modifications to existing configurations, thus not increasing production costs. Furthermore, based on the internal overload protection of the CNC system, it adds monitoring functionality to the PLC, realizing a multi-machine protection mechanism. When an overload alarm occurs, it can automatically generate text in real time, recording the current machine tool information, and does not easily reset to clear the alarm, effectively protecting the field status and facilitating the identification of the cause of the anomaly. This invention has strong versatility, adaptable to different motor configurations and different hardware connection sequences, and its functionality is unified and easy to operate. Attached Figure Description

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0033] Figure 1 This is a basic flowchart of the method according to the present invention.

[0034] Figure 2 This is a schematic diagram illustrating the effect of shaft drive number setting according to an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram illustrating the effect of the shaft drive number index according to an embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram illustrating the effect of shaft overload condition setting according to an embodiment of the present invention.

[0037] Figure 5 This is a schematic diagram illustrating the effect of the shaft overload relief mode according to an embodiment of the present invention. Detailed Implementation

[0038] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0039] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "upper," "lower," "left," "right," "top," and "bottom" used in this invention are only relative to the relative positional relationships of the various components of the invention in the accompanying drawings.

[0040] Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and not for limiting the invention. The term "and / or" as used herein includes any combination of one or more of the associated listed items.

[0041] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various elements, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from one another. For example, without departing from the scope of this disclosure, a first element may also be referred to as a second element, and similarly, a second element may also be referred to as a first element.

[0042] See Figures 1 to 5 The present invention provides a method for shaft overload protection in CNC machining, which includes at least the following steps:

[0043] S100: Obtain the user-defined shaft overload drive number and the set shaft overload conditions;

[0044] S200 uses a time-division polling method via PLC to continuously read shaft current information in real time;

[0045] S300: Based on the shaft overload drive number and the shaft overload condition, determine whether a shaft overload has occurred according to the read shaft current information; when a shaft overload occurs, perform alarm processing and generate current device information text, and perform a lock or unlock operation according to user settings; wherein, after performing alarm lock, perform alarm lock release operation according to the input password.

[0046] This invention relates to a control method and system for axis overload protection in CNC machining. When a machine tool is subjected to a collision, it can promptly trigger an alarm and effectively reduce damage. By directly monitoring the real-time load of the axis, it effectively solves the lag and error problems caused by indirect monitoring, improving the real-time performance and accuracy of detection and protection, and effectively preventing damage. This invention uses a CNC system function development approach to achieve axis overload protection locking. Protection is achieved through the cooperation between the PLC and NC, without requiring external hardware or modifications to existing configurations, thus not increasing production costs. Furthermore, based on the internal overload protection of the CNC system, it adds monitoring functionality to the PLC, realizing a multi-machine protection mechanism. When an overload alarm occurs, it can automatically generate text in real time, recording the current machine tool information, and does not easily reset to clear the alarm, effectively protecting the field status and facilitating the identification of the cause of the anomaly. This invention has strong versatility, adaptable to different motor configurations and different hardware connection sequences, and its functionality is unified and easy to operate.

[0047] In some embodiments, the method of the present invention uses a time-division polling approach to read the axis current information of each moving axis of the device in real time, and uses the read current values ​​as the basis for determining axis overload. The present invention uses a PLC to continuously collect the current and torque of each axis in real time, and adopts a short-cycle scanning method, which can effectively monitor current changes and respond quickly, achieving real-time and accurate axis overload monitoring and protection.

[0048] Specifically, to achieve shaft overload protection, it is first necessary to determine the criteria for judging whether the shaft is overloaded. The method of this invention uses the most intuitive current parameter as the criterion. In addition, unlike the existing system which can only read one drive variable through the PLC at a time, this invention uses a time-division polling method to obtain shaft current information.

[0049] In one application embodiment, the system of the present invention has a polling timer function, which performs the following operations sequentially through ladder logic: First, when the system's always-true status flag (i.e., SM0.0) ​​is true, the program enters the main logic flow. At the beginning of the flow, if the polling status flag (i.e., M70.0) is false, the first timer is started to delay for N time units (e.g., 5 time units); when the first timer (i.e., T163) finishes its delay, the polling status flag is set to true. Subsequently, under the condition that the polling status flag is true, the second timer (i.e., T164) is started to delay for M time units (e.g., 10 time units), while the system collects shaft current information; finally, when the second timer finishes its delay, the polling status flag is reset to false, thus forming a loop control logic containing two levels of delay (e.g., 5 units and 10 units), realizing the periodic polling timing function.

[0050] Specifically, experimental verification shows that to accurately obtain the current axis information, reading the current information of a single axis requires 150ms. Based on the equipment with a reserved four- or five-axis turntable configuration, the time required for this invention to poll the axis current information for one revolution is 900ms. Adding the reading idle period, the entire reading time is about 1 second, which can realize short-cycle polling to obtain axis current information, effectively monitor current changes in real time and make rapid responses.

[0051] In some embodiments, the method of the present invention can customize the shaft overload drive number. Addressing the differences in electrical connections between shafts across different machine models, it employs an open interface to adapt to different drive numbers for different shafts, thereby improving versatility. See also Figure 2 and Figure 3 After setting the axis drive number using the method of this invention, the axis allocation under the current hardware connection can be viewed. By entering the corresponding drive number in the setting parameters, the correct axis information can be obtained.

[0052] Specifically, the method of this invention defines the drive number of an axis using a counter. The execution process includes: the system initiates the drive number definition process through a normally open contact (SM0.0). First, it checks if the polling status flag (M70.0) is true. Then, the system executes a counter value comparison instruction to determine if the accumulated value of the current counter (e.g., C6) is greater than or equal to a preset threshold K (e.g., +5). When this condition is met, the system triggers a counter increment instruction (CTU) to increment the counter (e.g., C6) and sets the upper limit of the increment to K (e.g., +5). During the counter increment operation, the system dynamically generates the corresponding axis drive number based on the current value of the counter (e.g., C6). Specifically, when the counter (e.g., C6) completes a full counting cycle from 0 to K (e.g., +5), the system automatically assigns a unique drive number identifier to the currently controlled motion axis. This drive number maintains a mapping relationship with the analog-to-digital conversion result of the counter, thereby realizing the function of defining the axis drive number through the counter status. The process of defining the drive number specifically occurs during the state transition phase when the counter (such as C6) performs an accumulation operation and reaches a preset threshold K (such as +5). At this time, the system converts the output value of the counter into the corresponding axis drive number code, thus completing the logical definition of the drive number.

[0053] In some application embodiments, the method of the present invention reads predefined drive parameter numbers and their corresponding configuration data according to the definition of axis drive parameters of any axis. Taking the X-axis as an example, its execution operation includes: when the status bit of the first data block (i.e., DB2700.DBX3.0) is false and the current value of the counter (i.e., C6) is equal to the first preset value (e.g., +1), the program performs corresponding data transmission operations according to the different values ​​of the status word of the second data block (e.g., DB4500.DBW62). Specifically, when the status word is equal to the first preset value (e.g., +1), the values ​​101 to 104 (the first preset parameter numbers) are written to the specified bytes (e.g., DBB1000) of the target data block (e.g., DB1200 to DB1203); when the status word is equal to the second preset value (e.g., +2), the values ​​105 to 108 (the second preset parameter numbers) are written to the same position; when the status word is equal to the third preset value (e.g., +3), the values ​​109 to 112 (the third preset parameter numbers) are written to the same position.

[0054] Furthermore, in the subsequent variable index setting for one of the axes (e.g., the X-axis) in the network, when the same initial conditions are met, the program writes the corresponding preset parameter codes (e.g., values ​​113 to 116, 117 to 120, and 121 to 124) into the corresponding positions of the target data block according to the different values ​​of the status word (e.g., preset value 4 (e.g., +4), preset value 5 (e.g., +5), and preset value 6 (e.g., +6)). Specifically, in the conditional judgment step where the system checks if the status word (e.g., DB4500.DBW62) matches the preset value (e.g., +1 to +6), the drive parameter number is read. When the condition is met, the system immediately reads the corresponding parameter number (e.g., 101 to 124) from the preset parameter library and writes it to the designated storage area, completing the dynamic configuration of the drive parameter number.

[0055] It should be noted that the values ​​such as 101 to 124 in the method of this invention are only illustrative examples and not specific limitations. They can be flexibly customized according to the device control code (such as axis control instructions, speed parameters, position identifiers, etc.) or hardware address mapping values ​​(such as servo driver register numbers) in actual applications.

[0056] In some application embodiments, the method of the present invention can read the defined drive parameters of any axis (such as the X-axis). The operation includes: when a timer trigger signal (i.e., T167) is activated, the system detects the current value of the parameter selection register (e.g., DB4500.DBW62). If this value is equal to a preset condition 1 (e.g., +1), the first set of parameter configuration procedures is executed: the system sequentially checks the values ​​of each register in the parameter identifier register group. When the value of the first parameter identifier register (e.g., DB1200.DBB1000) is equal to 101, the data from the first parameter storage area (e.g., DB1200.DBD3016) is transferred to the drive parameter storage area (e.g., DB9048.DBD0); when the value of the second parameter identifier register (e.g., DB1201.DBB1000) is equal to 102, the data from the second parameter storage area (e.g., DB1201.DBD3016) is transferred to the drive parameter storage area (e.g., DB9048.DBD0). DB9048.DBD24) is used to back up the data to a temporary storage unit (such as MD56); when the value of the third parameter identifier register (such as DB1202.DBB1000) is equal to 103, the data in the third parameter storage area (such as DB1202.DBD3016) is transferred to the driver parameter storage area (such as DB9048.DBD48); when the value of the fourth parameter identifier register (such as DB1203.DBB1000) is equal to 104, the data in the fourth parameter storage area (such as DB1203.DBD3016) is transferred to the driver parameter storage area (such as DB9048.DBD72).

[0057] Furthermore, if the value of the parameter selection register (e.g., DB4500.DBW62) is equal to the preset condition 2 (e.g., +2), then the second set of parameter configuration procedures is executed. The specific steps are similar to the first set, except that the comparison value of the parameter identifier register changes to 105 to 108, and the rest of the operations are the same. When the value of the parameter selection register is equal to the preset condition 3 (e.g., +3), the third set of parameter configuration procedures is executed, and the comparison value changes to 109 to 112; when it is equal to the preset condition 4 (e.g., +4), the fourth set of procedures is executed, and the comparison value changes to 113 to 116; when it is equal to the preset condition 5 (e.g., +5), the fifth set of procedures is executed, and the comparison value changes to 117 to 120; when it is equal to the preset condition 6 (e.g., +6), the sixth set of procedures is executed, and the comparison value changes to 121 to 124.

[0058] It is understood that this invention, by setting axis drive numbers, is compatible with all configurations. For different machine types (such as CNC machine tools, robotic arms, etc.), the electrical connection methods (such as drive numbers and signal interfaces) of each axis may differ. By decoupling the logical axis numbers (such as X-axis, Y-axis) from the physical drive numbers (such as 101, 201), the system can dynamically adapt to the hardware configurations of different machine types. Therefore, there is no need to modify the core control program; only the drive number configuration needs to be adjusted to adapt to new machine types (e.g., mapping the X-axis drive number from 101 to 201 through a configuration file to achieve compatibility with machine type B). It supports subsequent hardware upgrades or modifications, such as changing the drive model or adding a new axis. Only the drive number definition needs to be updated; there is no need to reconstruct the software logic, and the existing control architecture is not affected, effectively reducing development and maintenance costs.

[0059] Furthermore, the drive number is bound to the physical signal (such as current) of the axis. The system monitors the load status of a specific axis in real time through the drive number. For example, drive number 101 corresponds to the current sensor of the X-axis. When an overload is detected, a protection action (such as shutdown or alarm) is immediately triggered. Thus, when an overload alarm occurs, the faulty axis (such as drive number 101 corresponding to the X-axis) can be quickly located through the drive number.

[0060] In some embodiments, the method of the present invention can set shaft overload conditions. Specifically, different models correspond to different motor configurations, and under a specific motor configuration, the shaft overload conditions also need to be defined to adapt to the customer's on-site operating conditions. The present invention uses an open parameter interface for setting shaft overload conditions to adapt to the shaft overload current under different operating conditions. See also Figure 4 According to the rated current of the motor, the present invention sets a certain percentage of the shaft current exceeding the rated current as the basis for judging shaft overload, thereby adapting to the differences in shaft overload protection caused by different motors by setting the percentage.

[0061] In some application embodiments, the method of the present invention can customize axis overload conditions, set axis overload judgment parameter values ​​in a percentage manner, and set any axis overload to trigger an alarm. The operation steps include: First, the system starts the detection process through a normally open contact (i.e., SM0.0). When the first data block abnormal flag bit (e.g., DB4500.DBX1012.0) and the second data block running status bit (e.g., DB2700.DBX3.0) are both true, the system sequentially checks whether the value in each axis status data register is equal to a preset abnormal threshold (e.g., +207900). When the value of the first axis status register (e.g., DB1200.DBD3020) is equal to the preset abnormal threshold (e.g., +207900), the system triggers an alarm through rising edge detection (i.e., EU). The system sends and sets the abnormal status flag (e.g., +DB9048.DBX144.6); when the value of the second axis status register (e.g., +DB1201.DBD3020) is equal to the preset abnormal threshold (e.g., +207900), the system also sets the abnormal status flag (e.g., DB9048.DBX144.6); when the value of the third axis status register (e.g., DB1202.DBD3020) is equal to the preset abnormal threshold (e.g., +207900), the system continues to set the abnormal status flag (e.g., DB9048.DBX144.6); when the value of the fourth axis status register (e.g., DB1203.DBD3020) is equal to the preset abnormal threshold (e.g., +207900), the system sets the abnormal status flag again (e.g., DB9048.DBX144.6). Subsequently, the system checks whether the abnormal status byte (such as DB9048.DBB144) is not equal to 0. If the condition is met, the alarm output bit (such as DB1600.DBX10.1) is activated.

[0062] In some embodiments, see Figure 5 The method of this invention prevents easy reset after an alarm is triggered; only authorized personnel can perform the reset operation. The system also generates a status information file, facilitating management and cause tracing. Furthermore, the method can be configured to use either a lock-after-alarm setting or an unlock-after-alarm setting, depending on customer needs, and this setting can be flexibly configured via parameters. Moreover, when the lock-after-alarm setting is selected, unlocking requires a password or other specific operation, replacing the traditional arbitrary reset method, effectively preserving the scene and facilitating management.

[0063] The axis overload lock operation includes: when the system simultaneously detects that the first data block overload flag bit (e.g., DB4500.DBX1012.0) and the second data block running status bit (e.g., DB2700.DBX3.0) are true, the system sequentially checks whether the value of each axis status data register is equal to the preset overload threshold (e.g., +207900). Specifically, it first compares the value of the first axis status register (e.g., DB1200.DBD3020). When it equals the preset overload threshold (+207900), it sets the abnormal status flag bit (e.g., DB9048.D) via rising edge trigger (EU). BX144.6); Next, the value of the second axis status register (e.g., DB1201.DBD3020) is compared. When it equals the preset overload threshold (+207900), the corresponding exception flag is set. The value of the third axis status register (e.g., DB1202.DBD3020) is then compared. When it equals the preset overload threshold (+207900), the corresponding exception flag is set again. Finally, the value of the fourth axis status register (e.g., DB1203.DBD3020) is compared. When it equals the preset overload threshold (+207900), all exception flags are set. The system then checks whether the exception status byte (e.g., DB9048.DBB144) is non-zero. If the condition is met, the locking control signal (e.g., DB1600.DBX10.1) is immediately activated. This step is the specific locking action execution stage. In subsequent processing, the system uses a combination of logic involving the third data block reset signal (e.g., DB9905.DBX14.0) and either the fourth data block lock flag (e.g., DB9062.DBX0.0) or the first data block overload flag (e.g., DB4500.DBX1012.0), combined with the fifth data block enable signal (e.g., DB9060.DBX5.7), to ultimately reset the abnormal status byte (e.g., DB9048.DBB144) to 0, thus releasing the machine from lock. Furthermore, after an overload alarm occurs, the system generates a subroutine to record the alarm time, the location of the abnormality, and tool information for analyzing the cause of the abnormality.

[0064] In one application embodiment, the method of the present invention uses a set current percentage as the basis for judging axis overload. When the equipment is running, if the axis current read twice consecutively exceeds the set overload current (set current percentage), it is judged as axis overload and an alarm is triggered. After overload, the system displays an alarm prompt (e.g., "Machine tool status abnormal, do not move!"). Furthermore, when the system issues an overload alarm, the alarm cannot be cleared by a reset operation; a specific operation is required. Specifically, when an overload alarm occurs, the emergency stop button must be pressed first, then a password must be entered to activate the machine tool abnormality clearance mode, and finally the reset button on the MCP panel must be pressed to complete the alarm lock-up operation.

[0065] This invention's method is adaptable to different machine models, varying load conditions, motor configurations, and hardware connection differences. It is applicable to a wide range of CNC equipment, different hardware connection methods for different machine models, and various working conditions. It achieves this through read / write coordination between PLC logic and the NC / drive, eliminating the need for additional hardware costs. Simultaneously, it effectively and promptly identifies and alarms when the machine tool load is abnormal, reducing axis damage caused by collisions and associated maintenance costs. Furthermore, it adds axis overload protection to the existing CNC system's internal axis overload protection mechanism, enabling multi-level protection.

[0066] It should be noted that existing CNC systems (such as Siemens systems) primarily rely on limiting parameters such as current, power, or torque for axis overload protection. Furthermore, an overload alarm is only triggered after the current, power, or torque of the axis reaches its limit for a certain period. Specifically, existing axis overload protection methods only issue an overload alarm after a certain time has elapsed. Clearly, these methods exhibit significant lag in practical applications, easily leading to serious collisions. For example, a severe collision in a CNC machine tool can cause serious damage to the external protection system, yet the system may not issue an alarm. Similarly, in CNC equipment with high acceleration, such as drilling and tapping centers, collisions often result in more severe mechanical damage due to the large inertia of moving parts. Finally, in carbide machining, where the cutting tools and finished products are expensive, collisions can easily lead to significant economic losses. However, if the goal is to reduce the overload capacity of the shaft and issue an alarm earlier in case of an anomaly, parameters such as the extreme current, power, and torque need to be lowered. But for some machining models that require full utilization of equipment performance, lowering the extreme values ​​of these key parameters will directly limit the machining capacity of the equipment, making it unable to meet the process requirements of high-performance cutting. This contradiction between protection sensitivity and machining performance has become a technical bottleneck that existing overload protection technologies struggle to overcome.

[0067] The shaft overload protection method of this invention, applied to CNC machining, effectively overcomes the technical bottlenecks of existing technologies, such as monitoring lag, insufficient protection accuracy, and difficulty in fault tracing. Compared to traditional indirect monitoring methods based on internal system parameters, this invention uses direct load sensing technology to dynamically monitor the torque, axial force, and radial force of the drive shaft in real time, fundamentally eliminating time delays and measurement errors in signal transmission, ensuring accurate identification of potential risks in the early stages of load anomalies. This direct measurement method significantly improves the system's response speed, enabling overload protection to be triggered promptly before substantial damage to the mechanical structure, thereby effectively avoiding accuracy degradation caused by protection lag.

[0068] This invention significantly improves the accuracy of overload detection through multi-parameter fusion analysis and intelligent threshold dynamic adjustment technology. The system can automatically optimize protection thresholds based on machining conditions, effectively distinguishing between normal machining fluctuations and true overload states, and significantly reducing the probability of false alarms. Simultaneously, an innovative state-locking mechanism ensures that after an overload alarm is triggered, the system automatically saves complete operating status data, including load curves, motion parameters, and environmental variables, and maintains the alarm status until manual confirmation. This design not only prevents the loss of fault information due to accidental resets but also provides complete data support for subsequent fault diagnosis, enabling technicians to accurately determine the cause of the overload, such as tool malfunction, program error, or mechanical collision, and thus take targeted measures to prevent recurrence.

[0069] This invention significantly improves the accuracy of overload detection through multi-parameter fusion analysis and intelligent threshold dynamic adjustment technology. The system automatically optimizes protection thresholds based on machining conditions, effectively distinguishing between normal machining fluctuations and true overload states, thus significantly reducing the probability of false alarms. Simultaneously, this invention employs a state locking mechanism to ensure that after an overload alarm is triggered, the system automatically saves complete operating status data, including load curves, motion parameters, and environmental variables, and maintains the alarm state until manual confirmation. This not only prevents the loss of fault information due to accidental resets but also provides complete data support for subsequent fault diagnosis, enabling technicians to accurately determine the cause of the overload, such as tool malfunction, program error, or mechanical collision, facilitating targeted measures to prevent recurrence.

[0070] It should be understood that the method steps in the embodiments of the present invention can be implemented or carried out by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable storage medium. The method can use standard programming techniques. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with the computer system. However, if necessary, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. Furthermore, for this purpose, the program can run on a programmed application-specific integrated circuit (ASIC).

[0071] Furthermore, the procedures described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by the context. The procedures described herein (or variations and / or combinations thereof) may be executed under the control of one or more computer systems configured with executable instructions, and may be implemented by hardware or a combination thereof as code (e.g., executable instructions, one or more computer programs, or one or more applications) that commonly executes on one or more processors. The computer program comprises a plurality of instructions executable by one or more processors.

[0072] Furthermore, the method can be implemented in any suitable type of computing platform, including but not limited to personal computers, minicomputers, mainframes, workstations, networked or distributed computing environments, standalone or integrated computer platforms, or in communication with charged particle tools or other imaging devices, etc. Aspects of the invention can be implemented as machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, optical read and / or write storage medium, RSM, ROM, etc., such that it can be read by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the processes described herein. Furthermore, the machine-readable code, or portions thereof, can be transmitted via wired or wireless networks. The invention described herein includes these and other different types of non-transitory computer-readable storage media when such media comprises instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor. When programmed according to the methods and techniques described in the invention, the invention may also include the computer itself.

[0073] A computer program can be applied to input data to perform the functions described herein, thereby transforming the input data to generate output data stored in non-volatile memory. The output information can also be applied to one or more output devices, such as a display. In a preferred embodiment of the invention, the transformed data represents physical and tangible objects, including specific visual depictions of physical and tangible objects generated on the display.

[0074] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention, as long as they achieve the technical effects of the present invention by the same means, should be included within the scope of protection of the present invention. Within the scope of protection of the present invention, the technical solutions and / or implementation methods can have various modifications and variations.

Claims

1. A method for shaft overload protection applied to CNC machining, the method comprising the following steps: S100: Obtain the user-defined shaft overload drive number and the set shaft overload conditions; S200 uses a time-division polling method via PLC to continuously read shaft current information in real time; S300: Based on the shaft overload drive number and the shaft overload condition, determine whether a shaft overload has occurred according to the read shaft current information; when a shaft overload occurs, perform alarm processing and generate current device information text, and perform a lock or unlock operation according to user settings; wherein, after performing alarm lock, perform an alarm lock release operation according to the input password; In step S100, the overload drive number of the shaft is defined using a counter, which includes the following steps: S111, Start the driver number definition process through the normally open contact; S112. When the polling status flag is detected to be true, execute the counter value comparison instruction to determine whether the current cumulative counter value is greater than or equal to the preset threshold K. S113. When the condition is greater than or equal to the preset threshold K, a counter increment instruction is triggered to perform an accumulation operation on the counter, and the accumulation limit is set to K. S114. During the counter accumulation operation, the corresponding axis drive number is dynamically generated based on the current value of the counter. In step S100, based on the definition of the axis drive parameters of any axis, the predefined drive parameter number and its corresponding configuration data are dynamically read by matching the values ​​of the status word, and the parameter number is written into the designated parameter storage area to complete the intelligent configuration of the drive parameters. This includes the following steps: when the status bit of the first data block is detected to be false and the current value of the counter is equal to the first preset value, corresponding data transmission operations are performed according to the different values ​​of the status word of the second data block. These data transmission operations include: when the status word is equal to the first preset value, writing the first preset parameter number into the designated bytes of the target data block; when the status word is equal to the second preset value, writing the second preset parameter number into the corresponding position; and when the status word is equal to the third preset value, writing the third preset parameter number into the corresponding position. In step S200, the PLC continuously collects the current and torque of each axis in real time. The process employs a two-stage delay-based cyclic control method for periodic polling to rapidly acquire shaft current information in real time. The reading of the shaft current information includes the following steps: S210. When the system's always-true status flag is true, proceed to the main logic flow. S220. At the beginning of the process, if the polling status flag is false, start the first timer for a delay of N time units. S230. When the first timer delay is completed, set the polling status flag to true; S240. When the polling status flag is true, start the second timer; delay for M time units, and simultaneously collect shaft current information; S250. When the second timer delay ends, the polling status flag is reset to false. S260, repeat steps S210 to S250 until a stop processing command is received.

2. The method according to claim 1, characterized in that, In the setting of shaft overload conditions in step S100, the shaft current is set to exceed the rated current by a certain percentage according to the rated current of the motor as the basis for judging shaft overload.

3. The method according to claim 2, characterized in that, The shaft overload alarm processing in step S300 includes the following steps: S311. When the first data block error flag bit and the second data block running status bit are both true, check in turn whether the value in each axis status data register is equal to the preset error threshold; wherein, when the value of a certain axis status register is equal to the preset error threshold, the corresponding error status flag bit is set. S312. Check if the abnormal status byte is not equal to 0. If the condition is met, activate the alarm output bit.

4. The method according to claim 3, characterized in that, The alarm lock release operation in step S300 includes the following steps: based on the combination logic of the third data block reset signal and not the fourth data block lock flag, or the first data block abnormal flag bit, combined with the fifth data block enable signal, the abnormal status byte is finally reset to 0 to release the machine lock state.

5. A computer-readable storage medium having stored thereon program instructions that, when executed by a processor, perform the method as described in any one of claims 1 to 4.

6. An axis overload protection system applied to CNC machining, characterized in that, include: A computer device, the computer device comprising the computer-readable storage medium according to claim 5.

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