Spindle water cooling machine control method, system and medium for high-precision numerical control machine tool

Abstract

The application provides a spindle water cooling machine control method, system and medium for a high-precision numerical control machine tool. The method comprises the following steps: determining the working state of the spindle, controlling the shunt flow of a three-way shunt valve according to the working state, obtaining the control strategy of the three-way shunt valve, and controlling the three-way shunt valve to control the cooling water according to the control strategy. The application realizes the switching of the cooling water between the spindle branch and the bypass loop by setting the three-way shunt valve, and solves the problem of sudden cooling shrinkage caused by continuous cooling when the spindle temporarily stops by combining the dynamic adjustment of the frequency conversion water pump and the refrigeration device by the control unit, avoids the problems of low efficiency and reduced equipment service life caused by frequent start-stop or continuous full-load operation of the water cooling machine, and thus realizes the intelligent control of the spindle water cooling machine of the high-precision numerical control machine tool.

Description

Technical Field

[0001] This application relates to the field of CNC machine tool technology, and more specifically, to a control method, system, and medium for a spindle water cooler used in a high-precision CNC machine tool. Background Technology

[0002] In high-precision CNC machine tool machining, the temperature stability of the spindle directly affects machining accuracy. Currently, the design of ordinary water chillers mainly focuses on heat dissipation during spindle thermal expansion, but ignores the problem of thermal contraction when the spindle suddenly stops at high speed. Furthermore, the frequent on / off cycles of water chillers have many drawbacks. CNC machine tools often need to be temporarily stopped during machining. At this time, the spindle stops rotating, and the heat generated decreases sharply. However, the refrigeration unit and water pump of traditional water chillers usually continue to run. The low-temperature cooling water continues to flow through the stationary spindle, causing the spindle temperature to drop sharply, resulting in significant thermal contraction. This severely affects its geometric and positional accuracy, leading to unstable machining accuracy. If the refrigeration unit and water pump continue to run at full load when the machine tool stops, the spindle will be over-cooled. If the refrigeration unit and water pump are completely shut down, the water temperature in the water chiller tank will gradually rise. Simultaneously, the frequent start-stop cycles of the refrigeration unit (traditional complete shutdown solution) shorten the lifespan of the compressor and the entire water cooling system. Therefore, there is an urgent need for a water chiller control method that can accurately control the cooling state when the spindle is temporarily stopped, balancing machining accuracy, energy consumption, and equipment lifespan.

[0003] Effective technical solutions are urgently needed to address the above problems. Summary of the Invention

[0004] The purpose of this application is to provide a control method, system, and medium for a spindle water chiller for high-precision CNC machine tools. By setting a three-way diverter valve, the cooling water can be switched between the spindle branch and the bypass circuit. Combined with the dynamic adjustment of the variable frequency water pump and the refrigeration unit by the control unit, the problem of sudden cooling and contraction caused by continuous cooling when the spindle is temporarily stopped is solved. At the same time, the problems of low efficiency and reduced equipment life caused by frequent start-stop or continuous full-load operation of the water chiller are avoided, thereby realizing intelligent control of the spindle water chiller for high-precision CNC machine tools.

[0005] In a first aspect, this application provides a spindle water-cooler control method for high-precision CNC machine tools, comprising the following steps:

[0006] Obtain the working status of the spindle;

[0007] The control strategy of the three-way diverter valve is obtained by controlling the diversion flow rate of the three-way diverter valve according to the working state.

[0008] The cooling water is controlled by controlling the three-way diverter valve according to the control strategy.

[0009] Optionally, in the spindle water-cooler control method for high-precision CNC machine tools described in this application, obtaining the spindle's working state includes:

[0010] The spindle's working status is obtained according to the preset machining program;

[0011] The operating status includes normal processing status or temporary shutdown status.

[0012] Optionally, in the spindle water-cooled machine control method for high-precision CNC machine tools described in this application, the step of controlling the flow rate of the three-way diverter valve according to the working state to obtain the control strategy of the three-way diverter valve includes:

[0013] If the working state is a normal processing state, then a first control strategy is generated;

[0014] If the operating state is a temporary shutdown state, then a second control strategy is generated;

[0015] The corresponding three-way diverter valve opening is obtained by querying the preset three-way diverter valve opening mapping table according to the first control strategy or the second control strategy.

[0016] Optionally, the spindle water-cooled machine control method for high-precision CNC machine tools described in this application further includes:

[0017] Identify the processing time points corresponding to temporary shutdown nodes based on the preset processing program;

[0018] The control parameters of the water chiller are pre-adjusted at a preset time point before the processing time point, and the operation of the water chiller is controlled according to the control parameters.

[0019] Adjust the three-way diverter valve according to the opening degree of the three-way diverter valve corresponding to the second control strategy based on the processing time point.

[0020] Optionally, the spindle water-cooled machine control method for high-precision CNC machine tools described in this application further includes:

[0021] Acquire historical ambient temperature, historical spindle load, historical spindle speed, historical spindle running time, and corresponding historical heat generation within a preset historical time period;

[0022] The initial spindle heating prediction model is trained based on the historical ambient temperature, historical spindle load, historical spindle speed, historical spindle running time, and corresponding historical heat generation to obtain a trained spindle heating prediction model.

[0023] The real-time ambient temperature, real-time spindle load, real-time spindle speed, and real-time spindle running time are acquired and input into the spindle heating prediction model for processing to obtain the real-time predicted heat generation.

[0024] The real-time predicted heat generation is compared with the preset heat generation control threshold;

[0025] If the real-time predicted heat generation is less than the preset heat generation control threshold, then normal execution will proceed;

[0026] If the real-time predicted heat generation is greater than or equal to the preset heat generation control threshold, the control parameters of the water chiller are adjusted.

[0027] Optionally, the spindle water-cooled machine control method for high-precision CNC machine tools described in this application further includes:

[0028] Obtain the real-time flow rate and pressure of the bypass circuit in the three-way diverter valve;

[0029] The real-time traffic flow is compared with the preset nominal traffic flow to obtain the traffic attenuation rate;

[0030] The real-time pressure is compared with the preset nominal pressure to obtain the pressure decay rate;

[0031] The bypass loop anomaly index is obtained by weighted summation of the flow rate attenuation rate and the pressure attenuation rate.

[0032] The bypass circuit anomaly index is compared with a preset bypass circuit anomaly threshold.

[0033] If the bypass circuit abnormality index is less than the preset bypass circuit abnormality threshold, the bypass circuit is determined to be normal.

[0034] If the bypass circuit abnormality index is greater than or equal to the preset bypass circuit abnormality threshold, the bypass circuit is determined to be abnormal.

[0035] Secondly, this application provides a spindle water-cooled machine control system for a high-precision CNC machine tool. The system includes a memory and a processor. The memory includes a program for a spindle water-cooled machine control method for a high-precision CNC machine tool. When the program for the spindle water-cooled machine control method for a high-precision CNC machine tool is executed by the processor, it performs the following steps:

[0036] Obtain the working status of the spindle;

[0037] The control strategy of the three-way diverter valve is obtained by controlling the diversion flow rate of the three-way diverter valve according to the working state.

[0038] The cooling water is controlled by controlling the three-way diverter valve according to the control strategy.

[0039] Optionally, in the spindle water-cooled machine control system for high-precision CNC machine tools described in this application, the step of acquiring the spindle's working state includes:

[0040] The spindle's working status is obtained according to the preset machining program;

[0041] The operating status includes normal processing status or temporary shutdown status.

[0042] Optionally, in the spindle water-cooled machine control system for high-precision CNC machine tools described in this application, the step of controlling the flow rate of the three-way diverter valve according to the working state to obtain the control strategy of the three-way diverter valve includes:

[0043] If the working state is a normal processing state, then a first control strategy is generated;

[0044] If the operating state is a temporary shutdown state, then a second control strategy is generated;

[0045] The corresponding three-way diverter valve opening is obtained by querying the preset three-way diverter valve opening mapping table according to the first control strategy or the second control strategy.

[0046] Thirdly, this application also provides a computer-readable storage medium storing a spindle water-cooled machine control method program for a high-precision CNC machine tool. When the spindle water-cooled machine control method program for a high-precision CNC machine tool is executed by a processor, it implements the steps of the spindle water-cooled machine control method for a high-precision CNC machine tool as described in any of the above claims.

[0047] As can be seen from the above, the spindle water chiller control method, system and medium provided in this application for high-precision CNC machine tools achieves the switching of cooling water in the spindle branch and bypass circuit by setting a three-way diversion valve, and combined with the dynamic adjustment of the variable frequency water pump and refrigeration device by the control unit, which solves the problem of sudden cooling and contraction caused by continuous cooling when the spindle is temporarily stopped. At the same time, it avoids the problems of low efficiency and reduced equipment life caused by frequent start-up and shutdown or continuous full-load operation of the water chiller, thereby realizing intelligent control of the spindle water chiller of high-precision CNC machine tools.

[0048] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing embodiments of this application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0049] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 A flowchart of a spindle water-cooler control method for high-precision CNC machine tools provided in this application embodiment;

[0051] Figure 2 A flowchart illustrating the control strategy for obtaining the three-way diverter valve in the spindle water cooler control method for high-precision CNC machine tools provided in this application embodiment;

[0052] Figure 3 A flowchart illustrating the real-time predicted heat generation of a spindle water chiller control method for high-precision CNC machine tools, provided in an embodiment of this application. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0054] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0055] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating a spindle water-cooler control method for a high-precision CNC machine tool according to some embodiments of this application. This spindle water-cooler control method for a high-precision CNC machine tool is used in terminal devices, such as computers and mobile terminals. The spindle water-cooler control method for a high-precision CNC machine tool includes the following steps:

[0056] S11. Obtain the working status of the spindle;

[0057] S12. Control the flow rate of the three-way diverter valve according to the working state to obtain the control strategy of the three-way diverter valve;

[0058] S13. Control the three-way diverter valve to control the cooling water according to the control strategy.

[0059] It should be noted that, in order to completely solve the problem of spindle sudden cooling and contraction, the working status of the spindle is monitored, and a three-way diverter valve is installed on the main return water pipe at the outlet of the refrigeration unit. The three-way diverter valve has one inlet and two outlets connected to the outlet of the refrigeration unit. The first outlet is connected to the pipe leading to the machine tool spindle cooling circuit, and the second outlet is connected to the bypass circuit that returns directly to the water tank. Based on the stop and start signals from the machine tool spindle, control commands are output to the three-way diverter valve to control the cooling water. Under normal machining conditions, most or all of the cooling water flows to the first outlet. When a temporary stop signal of the spindle is detected, the three-way diverter valve is controlled to make most or all of the cooling water flow to the second outlet (bypass branch), basically or completely cutting off the water flow to the spindle branch.

[0060] According to an embodiment of the present invention, obtaining the working state of the spindle includes:

[0061] The spindle's working status is obtained according to the preset machining program;

[0062] The operating status includes normal processing status or temporary shutdown status.

[0063] It should be noted that the spindle's working status is predicted based on the preset machining program. For example, when the control unit receives the machine tool's M01 stop signal, it determines that the machine is in a temporary stop state. However, in actual machining, the status may deviate from the program due to operator intervention, abnormal alarms, etc., and it is necessary to verify it in conjunction with the machine tool's real-time signals.

[0064] Please refer to Figure 2 , Figure 2 This is a flowchart illustrating the control strategy for obtaining a three-way flow divider valve in a spindle water-cooled machine tool control method according to some embodiments of this application. According to an embodiment of the present invention, the step of controlling the flow rate of the three-way flow divider valve based on the operating state to obtain the control strategy for the three-way flow divider valve includes:

[0065] S21. If the working state is a normal processing state, then a first control strategy is generated;

[0066] S22. If the working state is a temporary shutdown state, then a second control strategy is generated;

[0067] S23. Query the preset three-way diverter valve opening mapping table according to the first control strategy or the second control strategy to obtain the corresponding three-way diverter valve opening.

[0068] It should be noted that after accurately identifying the spindle's working state (normal machining state or temporary shutdown state), the control unit will generate a corresponding control strategy based on the state determination result: if it is determined to be a normal machining state, a first control strategy with "ensuring efficient cooling of the spindle" as its core will be generated immediately. This strategy focuses on providing sufficient cooling flow and stable water temperature for the continuously rotating and heating spindle; if it is determined to be a temporary shutdown state, a second control strategy with "preventing sudden cooling of the spindle + maintaining stable circulation inside the water chiller" as its core will be generated. The focus is on cutting off the cooling water flow to the stationary spindle and reducing system power consumption. Meanwhile, the control unit has a built-in preset three-way diverter valve opening mapping table. This table is pre-calibrated based on a large amount of operating data to determine the optimal opening parameters of the three-way diverter valve under different control strategies. For example, the first control strategy corresponds to the opening of "main shaft branch fully open / bypass branch fully closed" in the mapping table (e.g., main shaft branch opening 100%, bypass branch opening 0%), ensuring that most of the cooling water flows to the main shaft to meet the cooling requirements. The second control strategy corresponds to the opening of "main shaft branch fully closed / bypass branch fully open" (e.g., main shaft branch opening ≤ 5%, bypass branch opening ≥ 95%), which basically cuts off the water flow to the main shaft, maintaining only the cooling water circulating inside the water chiller. Finally, by querying the mapping table, the control unit quickly obtains and outputs the three-way diverter valve opening command that matches the current control strategy, ensuring the accuracy and timeliness of water circuit switching.

[0069] According to an embodiment of the present invention, it further includes:

[0070] Identify the processing time points corresponding to temporary shutdown nodes based on the preset processing program;

[0071] The control parameters of the water chiller are pre-adjusted at a preset time point before the processing time point, and the operation of the water chiller is controlled according to the control parameters.

[0072] Adjust the three-way diverter valve according to the opening degree of the three-way diverter valve corresponding to the second control strategy based on the processing time point.

[0073] It should be noted that by parsing the preset machining program, the actual machining time point corresponding to each temporary stop node is accurately calculated from the program segments containing temporary stop instructions such as M01 (optional stop), M00 (program pause), and M06 (tool change), combined with the current program execution progress and feed rate parameters (for example, if program segment N50 is parsed as an M01 instruction, and combined with the current feed path and speed, it is calculated that it will take 6 seconds to execute to this segment, that is, the temporary stop machining time point is 6 seconds later). Subsequently, at the preset time node before this machining time point (such as 3 seconds in advance), the control unit starts the pre-adjustment of the water chiller control parameters, such as raising the variable frequency water pump speed from the normal machining set value (such as 50Hz) in advance. The speed is reduced to a low level close to the shutdown requirement (e.g., 40Hz), and the power of the refrigeration unit is pre-reduced from the dynamic adjustment state to the base power (e.g., 45%, during high summer temperatures) to avoid the impact of sudden parameter changes on the system during temporary shutdown. When the processing time corresponding to the temporary shutdown is reached, the control unit immediately queries the preset three-way diverter valve opening mapping table to obtain the opening parameters corresponding to the second control strategy (adapting to the temporary shutdown state) (e.g., spindle branch opening ≤ 5%, bypass branch opening ≥ 95%), and sends an adjustment command to the three-way diverter valve to realize the rapid switching of cooling water from the spindle branch to the bypass circuit. This prevents the continuous flow of low-temperature cooling water through the stationary spindle from causing sudden cooling and contraction, and ensures the stability of the internal circulation of the water chiller.

[0074] Please refer to Figure 3 , Figure 3 This is a flowchart illustrating the real-time predicted heat generation method for controlling the spindle water cooler of a high-precision CNC machine tool, as described in some embodiments of this application. According to embodiments of the present invention, it further includes:

[0075] S31. Obtain the historical ambient temperature, historical spindle load, historical spindle speed, historical spindle running time, and corresponding historical heat generation within a preset historical time period.

[0076] S32. Train the initial spindle heating prediction model based on the historical ambient temperature, historical spindle load, historical spindle speed and historical spindle running time and the corresponding historical heat generation to obtain the trained spindle heating prediction model.

[0077] S33. Obtain the real-time ambient temperature, real-time spindle load, real-time spindle speed and real-time spindle running time, and input them into the spindle heating prediction model for processing to obtain the real-time predicted heat generation.

[0078] S34. Compare the real-time predicted heat generation with the preset heat generation control threshold;

[0079] S341. If the real-time predicted heat generation is less than the preset heat generation control threshold, then the operation proceeds normally.

[0080] S342. If the real-time predicted heat generation is greater than or equal to the preset heat generation control threshold, then adjust the control parameters of the water chiller.

[0081] It should be noted that, to achieve accurate prediction of spindle heat generation and dynamic adaptation of cooling parameters, the data acquisition module first acquires full-condition operating data within a preset historical time period (e.g., the past 3 months). This includes historical ambient temperature recorded by an ambient temperature sensor, historical spindle load and speed read from the machine tool PLC, historical spindle runtime statistics from system timing, and the corresponding historical heat generation. This constructs a historical dataset covering different seasonal temperatures (5℃~40℃), load ranges (0%~120%), and operating modes (continuous / intermittent machining). The historical spindle load is obtained from the real-time torque signal acquired from the spindle drive unit and converted. The historical heat generation is calculated based on spindle temperature changes, combined with material specific heat capacity and mass. Then, using historical ambient temperature, historical spindle load, historical spindle speed, and historical spindle runtime as input features, and the corresponding historical heat generation as the output target, the initial spindle heat generation prediction model (e.g., multivariate) is modified. The system trains a spindle heating prediction model using linear regression or gradient boosting tree models. During actual machining, the system collects real-time ambient temperature, spindle load, spindle speed, and spindle runtime, and inputs this real-time data into the trained model. The model quickly calculates and outputs the predicted heat generation using a preset algorithm. The control unit then compares this predicted heat generation with a preset heat control threshold. If the predicted heat generation is less than the threshold, the current cooling capacity is sufficient to meet the heat dissipation requirements, and the water chiller maintains its existing control parameters. If the predicted heat generation is greater than or equal to the threshold, it indicates a risk of spindle overheating. The control unit immediately triggers a parameter adjustment mechanism, such as increasing the variable frequency water pump speed to increase cooling flow (e.g., from 50Hz to 55Hz) or increasing the cooling device power to reduce water temperature (e.g., from 60% to 80%), thereby actively enhancing the cooling effect to prevent spindle overheating from affecting machining accuracy.

[0082] According to an embodiment of the present invention, it further includes:

[0083] Obtain the real-time flow rate and pressure of the bypass circuit in the three-way diverter valve;

[0084] The real-time traffic flow is compared with the preset nominal traffic flow to obtain the traffic attenuation rate;

[0085] The real-time pressure is compared with the preset nominal pressure to obtain the pressure decay rate;

[0086] The bypass loop anomaly index is obtained by weighted summation of the flow rate attenuation rate and the pressure attenuation rate.

[0087] The bypass circuit anomaly index is compared with a preset bypass circuit anomaly threshold.

[0088] If the bypass circuit abnormality index is less than the preset bypass circuit abnormality threshold, the bypass circuit is determined to be normal.

[0089] If the bypass circuit abnormality index is greater than or equal to the preset bypass circuit abnormality threshold, the bypass circuit is determined to be abnormal.

[0090] It should be noted that, in order to monitor the operating status of the bypass circuit of the three-way diverter valve in real time and promptly troubleshoot pipeline blockages or valve jamming, the real-time flow rate and pressure of the circuit are first collected by a high-precision flow meter and pressure sensor installed in the bypass circuit. Then, the difference between the collected real-time flow rate and the preset nominal flow rate of the bypass circuit under this operating condition is calculated, and then divided by the preset nominal flow rate to obtain the flow rate attenuation rate. Similarly, the pressure attenuation rate is calculated by comparing the real-time pressure with the preset nominal pressure. Considering that the flow rate attenuation has a more critical impact on the "internal circulation protection" function of the bypass circuit, this embodiment assigns a higher weight to the flow rate attenuation rate (e.g., weight 0.6). The pressure decay rate is assigned a corresponding weight (e.g., weight 0.4), and the weighted sum is used to quantify the overall abnormality of the loop. Finally, the calculated bypass loop abnormality index is compared with the preset bypass loop abnormality threshold. If the abnormality index is less than the threshold, it means that the bypass loop flow and pressure are within the normal fluctuation range, and the loop is judged to be operating normally. If the abnormality index is greater than or equal to the threshold, it indicates that there may be pipe blockage or three-way valve switching problems, and the bypass loop is judged to be abnormal. At this time, the control unit needs to immediately trigger an alarm and start the backup adjustment strategy, such as reducing the water pump speed to avoid excessive pressure and switching the backup bypass valve to ensure the stable operation of the water chiller system.

[0091] It is worth mentioning that, according to embodiments of the present invention, it further includes:

[0092] Based on the average historical downtime corresponding to the preset processing program;

[0093] The average historical downtime is compared with a preset historical downtime assessment threshold, and the downtime prediction level is determined based on the threshold range it falls into, including short downtime, medium downtime, or long downtime.

[0094] The control strategy for the water chiller is matched according to the downtime prediction level.

[0095] It should be noted that, to achieve precise matching between the water chiller control strategy and downtime, the average historical downtime of the same preset machining program is first calculated by using the actual downtime of each temporary stop node during historical execution (such as the waiting time after the M01 command, the tool change time of M06) recorded by the system. For example, in the past 100 executions of a certain machining program, the average temporary downtime is 2 minutes. Then, this average historical downtime is compared with the preset historical downtime evaluation threshold. In this embodiment, the short downtime threshold is set to 1 minute and the medium downtime threshold is set to 5 minutes. The downtime prediction is determined based on the range in which the average falls. The system assesses the shutdown level. If the average duration is ≤1 minute, it is classified as a short shutdown; if 1 minute < average duration ≤5 minutes, it is classified as a medium shutdown; and if the average duration >5 minutes, it is classified as a long shutdown. Finally, the system matches the corresponding water chiller control strategy based on the different shutdown prediction levels. For example, during a short shutdown, a higher base cooling power (40%) and water pump speed (35Hz) are maintained to ensure a rapid restart response. During a medium shutdown, the cooling power is appropriately reduced to 35% and the water pump speed to 30Hz to balance energy consumption and recovery speed. During a long shutdown, an intermittent cycle mode is activated (running for 10 seconds every 2 minutes) to further save energy, thereby achieving refined energy consumption control and ensuring cooling effect during shutdown.

[0096] It is worth mentioning that, according to embodiments of the present invention, it further includes:

[0097] Obtain the real-time spindle temperature and real-time water temperature after the spindle stops;

[0098] If the spindle returns to normal machining state, the real-time spindle temperature is compared with the preset spindle control temperature to obtain the spindle temperature difference;

[0099] The water pump speed adjustment strategy of the water chiller is matched according to the spindle temperature difference;

[0100] The real-time water temperature is compared with the preset standard water temperature;

[0101] If the real-time water temperature is less than or equal to the preset standard water temperature, the first cooling power control strategy of the water chiller will be matched.

[0102] If the real-time water temperature is higher than the preset standard water temperature, the second cooling power control strategy of the water chiller will be matched.

[0103] It should be noted that, to ensure the cooling system can quickly adapt to the spindle's heat dissipation needs and avoid sudden temperature changes when the spindle resumes normal machining from a temporary shutdown, the real-time spindle temperature and real-time cooling water temperature are first collected by a spindle temperature sensor and a temperature sensor in the water tank, respectively, after the spindle stops. When the spindle is detected to have resumed normal machining, the real-time spindle temperature is immediately compared with the preset spindle control temperature (the difference is calculated; for example, if the real-time temperature is 23℃ and the preset spindle control temperature is 25℃, the temperature difference is -2℃; if the real-time temperature is 27℃, the temperature difference is 2℃). Based on this temperature difference, a corresponding water pump speed adjustment strategy is matched. For example, if the temperature difference is negative (spindle temperature is lower than the control value), a strategy of slowly increasing the speed is adopted (e.g., increasing from 35Hz to 45Hz within 2 seconds to avoid further cooling of the spindle due to a sudden flow of low-temperature water); if the temperature difference is positive (spindle temperature is higher than the control value), the water pump speed is adjusted accordingly. When the spindle temperature is below 25℃, a strategy of rapidly increasing the spindle speed is adopted (e.g., increasing from 35Hz to 50Hz within 1 second to quickly increase the cooling flow). At the same time, the collected real-time water temperature is compared with the preset standard water temperature (e.g., the target water temperature of 25℃ during normal processing). If the real-time water temperature is ≤25℃, it means that the current water temperature meets the cooling requirements, and the first cooling power control strategy is matched (maintaining the current power or slowly increasing it to the normal level, such as gradually increasing it from 40% to 60%) to avoid overcooling. If the real-time water temperature is >25℃, it means that the water temperature is too high and needs to be cooled down faster, and the second cooling power control strategy is matched (immediately increasing the cooling power to a higher level, such as rapidly increasing it from 40% to 80%) to ensure that the cooling water temperature quickly drops back to the standard range. Finally, through the dual judgment of spindle temperature difference and water temperature, the coordinated adjustment of water pump speed and cooling power during the resumption of processing is achieved, taking into account both spindle temperature stability and cooling efficiency.

[0104] This invention also discloses a spindle water-cooler control system for high-precision CNC machine tools, including a memory and a processor. The memory includes a spindle water-cooler control method program for high-precision CNC machine tools. When the processor executes the spindle water-cooler control method program for high-precision CNC machine tools, it performs the following steps:

[0105] Obtain the working status of the spindle;

[0106] The control strategy of the three-way diverter valve is obtained by controlling the diversion flow rate of the three-way diverter valve according to the working state.

[0107] The cooling water is controlled by controlling the three-way diverter valve according to the control strategy.

[0108] It should be noted that, in order to completely solve the problem of spindle sudden cooling and contraction, the working status of the spindle is monitored, and a three-way diverter valve is installed on the main return water pipe at the outlet of the refrigeration unit. The three-way diverter valve has one inlet and two outlets connected to the outlet of the refrigeration unit. The first outlet is connected to the pipe leading to the machine tool spindle cooling circuit, and the second outlet is connected to the bypass circuit that returns directly to the water tank. Based on the stop and start signals from the machine tool spindle, control commands are output to the three-way diverter valve to control the cooling water. Under normal machining conditions, most or all of the cooling water flows to the first outlet. When a temporary stop signal of the spindle is detected, the three-way diverter valve is controlled to make most or all of the cooling water flow to the second outlet (bypass branch), basically or completely cutting off the water flow to the spindle branch.

[0109] According to an embodiment of the present invention, obtaining the working state of the spindle includes:

[0110] The spindle's working status is obtained according to the preset machining program;

[0111] The operating status includes normal processing status or temporary shutdown status.

[0112] It should be noted that the spindle's working status is predicted based on the preset machining program. For example, when the control unit receives the machine tool's M01 stop signal, it determines that the machine is in a temporary stop state. However, in actual machining, the status may deviate from the program due to operator intervention, abnormal alarms, etc., and it is necessary to verify it in conjunction with the machine tool's real-time signals.

[0113] According to an embodiment of the present invention, the step of controlling the flow rate of the three-way diverter valve based on the operating state to obtain the control strategy of the three-way diverter valve includes:

[0114] If the working state is a normal processing state, then a first control strategy is generated;

[0115] If the operating state is a temporary shutdown state, then a second control strategy is generated;

[0116] The corresponding three-way diverter valve opening is obtained by querying the preset three-way diverter valve opening mapping table according to the first control strategy or the second control strategy.

[0117] It should be noted that after accurately identifying the spindle's working state (normal machining state or temporary shutdown state), the control unit will generate a corresponding control strategy based on the state determination result: if it is determined to be a normal machining state, a first control strategy with "ensuring efficient cooling of the spindle" as its core will be generated immediately. This strategy focuses on providing sufficient cooling flow and stable water temperature for the continuously rotating and heating spindle; if it is determined to be a temporary shutdown state, a second control strategy with "preventing sudden cooling of the spindle + maintaining stable circulation inside the water chiller" as its core will be generated. The focus is on cutting off the cooling water flow to the stationary spindle and reducing system power consumption. Meanwhile, the control unit has a built-in preset three-way diverter valve opening mapping table. This table is pre-calibrated based on a large amount of operating data to determine the optimal opening parameters of the three-way diverter valve under different control strategies. For example, the first control strategy corresponds to the opening of "main shaft branch fully open / bypass branch fully closed" in the mapping table (e.g., main shaft branch opening 100%, bypass branch opening 0%), ensuring that most of the cooling water flows to the main shaft to meet the cooling requirements. The second control strategy corresponds to the opening of "main shaft branch fully closed / bypass branch fully open" (e.g., main shaft branch opening ≤ 5%, bypass branch opening ≥ 95%), which basically cuts off the water flow to the main shaft, maintaining only the cooling water circulating inside the water chiller. Finally, by querying the mapping table, the control unit quickly obtains and outputs the three-way diverter valve opening command that matches the current control strategy, ensuring the accuracy and timeliness of water circuit switching.

[0118] According to an embodiment of the present invention, it further includes:

[0119] Identify the processing time points corresponding to temporary shutdown nodes based on the preset processing program;

[0120] The control parameters of the water chiller are pre-adjusted at a preset time point before the processing time point, and the operation of the water chiller is controlled according to the control parameters.

[0121] Adjust the three-way diverter valve according to the opening degree of the three-way diverter valve corresponding to the second control strategy based on the processing time point.

[0122] It should be noted that by parsing the preset machining program, the actual machining time point corresponding to each temporary stop node is accurately calculated from the program segments containing temporary stop instructions such as M01 (optional stop), M00 (program pause), and M06 (tool change), combined with the current program execution progress and feed rate parameters (for example, if program segment N50 is parsed as an M01 instruction, and combined with the current feed path and speed, it is calculated that it will take 6 seconds to execute to this segment, that is, the temporary stop machining time point is 6 seconds later). Subsequently, at the preset time node before this machining time point (such as 3 seconds in advance), the control unit starts the pre-adjustment of the water chiller control parameters, such as raising the variable frequency water pump speed from the normal machining set value (such as 50Hz) in advance. The speed is reduced to a low level close to the shutdown requirement (e.g., 40Hz), and the power of the refrigeration unit is pre-reduced from the dynamic adjustment state to the base power (e.g., 45%, during high summer temperatures) to avoid the impact of sudden parameter changes on the system during temporary shutdown. When the processing time corresponding to the temporary shutdown is reached, the control unit immediately queries the preset three-way diverter valve opening mapping table to obtain the opening parameters corresponding to the second control strategy (adapting to the temporary shutdown state) (e.g., spindle branch opening ≤ 5%, bypass branch opening ≥ 95%), and sends an adjustment command to the three-way diverter valve to realize the rapid switching of cooling water from the spindle branch to the bypass circuit. This prevents the continuous flow of low-temperature cooling water through the stationary spindle from causing sudden cooling and contraction, and ensures the stability of the internal circulation of the water chiller.

[0123] According to an embodiment of the present invention, it further includes:

[0124] Acquire historical ambient temperature, historical spindle load, historical spindle speed, historical spindle running time, and corresponding historical heat generation within a preset historical time period;

[0125] The initial spindle heating prediction model is trained based on the historical ambient temperature, historical spindle load, historical spindle speed, historical spindle running time, and corresponding historical heat generation to obtain a trained spindle heating prediction model.

[0126] The real-time ambient temperature, real-time spindle load, real-time spindle speed, and real-time spindle running time are acquired and input into the spindle heating prediction model for processing to obtain the real-time predicted heat generation.

[0127] The real-time predicted heat generation is compared with the preset heat generation control threshold;

[0128] If the real-time predicted heat generation is less than the preset heat generation control threshold, then normal execution will proceed;

[0129] If the real-time predicted heat generation is greater than or equal to the preset heat generation control threshold, the control parameters of the water chiller are adjusted.

[0130] It should be noted that, to achieve accurate prediction of spindle heat generation and dynamic adaptation of cooling parameters, the data acquisition module first acquires full-condition operating data within a preset historical time period (e.g., the past 3 months). This includes historical ambient temperature recorded by an ambient temperature sensor, historical spindle load and speed read from the machine tool PLC, historical spindle runtime statistics from system timing, and the corresponding historical heat generation. This constructs a historical dataset covering different seasonal temperatures (5℃~40℃), load ranges (0%~120%), and operating modes (continuous / intermittent machining). The historical spindle load is obtained from the real-time torque signal acquired from the spindle drive unit and converted. The historical heat generation is calculated based on spindle temperature changes, combined with material specific heat capacity and mass. Then, using historical ambient temperature, historical spindle load, historical spindle speed, and historical spindle runtime as input features, and the corresponding historical heat generation as the output target, the initial spindle heat generation prediction model (e.g., multivariate) is modified. The system trains a spindle heating prediction model using linear regression or gradient boosting tree models. During actual machining, the system collects real-time ambient temperature, spindle load, spindle speed, and spindle runtime, and inputs this real-time data into the trained model. The model quickly calculates and outputs the predicted heat generation using a preset algorithm. The control unit then compares this predicted heat generation with a preset heat control threshold. If the predicted heat generation is less than the threshold, the current cooling capacity is sufficient to meet the heat dissipation requirements, and the water chiller maintains its existing control parameters. If the predicted heat generation is greater than or equal to the threshold, it indicates a risk of spindle overheating. The control unit immediately triggers a parameter adjustment mechanism, such as increasing the variable frequency water pump speed to increase cooling flow (e.g., from 50Hz to 55Hz) or increasing the cooling device power to reduce water temperature (e.g., from 60% to 80%), thereby actively enhancing the cooling effect to prevent spindle overheating from affecting machining accuracy.

[0131] According to an embodiment of the present invention, it further includes:

[0132] Obtain the real-time flow rate and pressure of the bypass circuit in the three-way diverter valve;

[0133] The real-time traffic flow is compared with the preset nominal traffic flow to obtain the traffic attenuation rate;

[0134] The real-time pressure is compared with the preset nominal pressure to obtain the pressure decay rate;

[0135] The bypass loop anomaly index is obtained by weighted summation of the flow rate attenuation rate and the pressure attenuation rate.

[0136] The bypass circuit anomaly index is compared with a preset bypass circuit anomaly threshold.

[0137] If the bypass circuit abnormality index is less than the preset bypass circuit abnormality threshold, the bypass circuit is determined to be normal.

[0138] If the bypass circuit abnormality index is greater than or equal to the preset bypass circuit abnormality threshold, the bypass circuit is determined to be abnormal.

[0139] It should be noted that, in order to monitor the operating status of the bypass circuit of the three-way diverter valve in real time and promptly troubleshoot pipeline blockages or valve jamming, the real-time flow rate and pressure of the circuit are first collected by a high-precision flow meter and pressure sensor installed in the bypass circuit. Then, the difference between the collected real-time flow rate and the preset nominal flow rate of the bypass circuit under this operating condition is calculated, and then divided by the preset nominal flow rate to obtain the flow rate attenuation rate. Similarly, the pressure attenuation rate is calculated by comparing the real-time pressure with the preset nominal pressure. Considering that the flow rate attenuation has a more critical impact on the "internal circulation protection" function of the bypass circuit, this embodiment assigns a higher weight to the flow rate attenuation rate (e.g., weight 0.6). The pressure decay rate is assigned a corresponding weight (e.g., weight 0.4), and the weighted sum is used to quantify the overall abnormality of the loop. Finally, the calculated bypass loop abnormality index is compared with the preset bypass loop abnormality threshold. If the abnormality index is less than the threshold, it means that the bypass loop flow and pressure are within the normal fluctuation range, and the loop is judged to be operating normally. If the abnormality index is greater than or equal to the threshold, it indicates that there may be pipe blockage or three-way valve switching problems, and the bypass loop is judged to be abnormal. At this time, the control unit needs to immediately trigger an alarm and start the backup adjustment strategy, such as reducing the water pump speed to avoid excessive pressure and switching the backup bypass valve to ensure the stable operation of the water chiller system.

[0140] It is worth mentioning that, according to embodiments of the present invention, it further includes:

[0141] Based on the average historical downtime corresponding to the preset processing program;

[0142] The average historical downtime is compared with a preset historical downtime assessment threshold, and the downtime prediction level is determined based on the threshold range it falls into, including short downtime, medium downtime, or long downtime.

[0143] The control strategy for the water chiller is matched according to the downtime prediction level.

[0144] It should be noted that, to achieve precise matching between the water chiller control strategy and downtime, the average historical downtime of the same preset machining program is first calculated by using the actual downtime of each temporary stop node during historical execution (such as the waiting time after the M01 command, the tool change time of M06) recorded by the system. For example, in the past 100 executions of a certain machining program, the average temporary downtime is 2 minutes. Then, this average historical downtime is compared with the preset historical downtime evaluation threshold. In this embodiment, the short downtime threshold is set to 1 minute and the medium downtime threshold is set to 5 minutes. The downtime prediction is determined based on the range in which the average falls. The system assesses the shutdown level. If the average duration is ≤1 minute, it is classified as a short shutdown; if 1 minute < average duration ≤5 minutes, it is classified as a medium shutdown; and if the average duration >5 minutes, it is classified as a long shutdown. Finally, the system matches the corresponding water chiller control strategy based on the different shutdown prediction levels. For example, during a short shutdown, a higher base cooling power (40%) and water pump speed (35Hz) are maintained to ensure a rapid restart response. During a medium shutdown, the cooling power is appropriately reduced to 35% and the water pump speed to 30Hz to balance energy consumption and recovery speed. During a long shutdown, an intermittent cycle mode is activated (running for 10 seconds every 2 minutes) to further save energy, thereby achieving refined energy consumption control and ensuring cooling effect during shutdown.

[0145] It is worth mentioning that, according to embodiments of the present invention, it further includes:

[0146] Obtain the real-time spindle temperature and real-time water temperature after the spindle stops;

[0147] If the spindle returns to normal machining state, the real-time spindle temperature is compared with the preset spindle control temperature to obtain the spindle temperature difference;

[0148] The water pump speed adjustment strategy of the water chiller is matched according to the spindle temperature difference;

[0149] The real-time water temperature is compared with the preset standard water temperature;

[0150] If the real-time water temperature is less than or equal to the preset standard water temperature, the first cooling power control strategy of the water chiller will be matched.

[0151] If the real-time water temperature is higher than the preset standard water temperature, the second cooling power control strategy of the water chiller will be matched.

[0152] It should be noted that, to ensure the cooling system can quickly adapt to the spindle's heat dissipation needs and avoid sudden temperature changes when the spindle resumes normal machining from a temporary shutdown, the real-time spindle temperature and real-time cooling water temperature are first collected by a spindle temperature sensor and a temperature sensor in the water tank, respectively, after the spindle stops. When the spindle is detected to have resumed normal machining, the real-time spindle temperature is immediately compared with the preset spindle control temperature (the difference is calculated; for example, if the real-time temperature is 23℃ and the preset spindle control temperature is 25℃, the temperature difference is -2℃; if the real-time temperature is 27℃, the temperature difference is 2℃). Based on this temperature difference, a corresponding water pump speed adjustment strategy is matched. For example, if the temperature difference is negative (spindle temperature is lower than the control value), a strategy of slowly increasing the speed is adopted (e.g., increasing from 35Hz to 45Hz within 2 seconds to avoid further cooling of the spindle due to a sudden flow of low-temperature water); if the temperature difference is positive (spindle temperature is higher than the control value), the water pump speed is adjusted accordingly. When the spindle temperature is below 25℃, a strategy of rapidly increasing the spindle speed is adopted (e.g., increasing from 35Hz to 50Hz within 1 second to quickly increase the cooling flow). At the same time, the collected real-time water temperature is compared with the preset standard water temperature (e.g., the target water temperature of 25℃ during normal processing). If the real-time water temperature is ≤25℃, it means that the current water temperature meets the cooling requirements, and the first cooling power control strategy is matched (maintaining the current power or slowly increasing it to the normal level, such as gradually increasing it from 40% to 60%) to avoid overcooling. If the real-time water temperature is >25℃, it means that the water temperature is too high and needs to be cooled down faster, and the second cooling power control strategy is matched (immediately increasing the cooling power to a higher level, such as rapidly increasing it from 40% to 80%) to ensure that the cooling water temperature quickly drops back to the standard range. Finally, through the dual judgment of spindle temperature difference and water temperature, the coordinated adjustment of water pump speed and cooling power during the resumption of processing is achieved, taking into account both spindle temperature stability and cooling efficiency.

[0153] A third aspect of the present invention provides a readable storage medium storing a spindle water-cooled machine control method program for a high-precision CNC machine tool, wherein when the spindle water-cooled machine control method program for a high-precision CNC machine tool is executed by a processor, the steps of the spindle water-cooled machine control method for a high-precision CNC machine tool as described in any of the preceding claims are implemented.

[0154] The present invention discloses a spindle water chiller control method, system, and medium for high-precision CNC machine tools. By setting a three-way diversion valve to switch the cooling water between the spindle branch circuit and the bypass circuit, and combining the control unit to dynamically adjust the variable frequency water pump and the refrigeration device, the problem of sudden cooling and contraction caused by continuous cooling when the spindle is temporarily stopped is solved. At the same time, it avoids the problems of low efficiency and reduced equipment lifespan caused by frequent start-stop or continuous full-load operation of the water chiller, thereby realizing intelligent control of the spindle water chiller for high-precision CNC machine tools.

[0155] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0156] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0157] In addition, in the various embodiments of the present invention, each functional unit can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0158] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0159] Alternatively, if the integrated units of this invention are implemented as software functional modules and sold or used as independent products, they can also be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

Claims

1. A control method for a spindle water cooler used in high-precision CNC machine tools, characterized in that, Includes the following steps: Obtain the working status of the spindle; The control strategy of the three-way diverter valve is obtained by controlling the diversion flow rate of the three-way diverter valve according to the working state. The three-way diverter valve is controlled according to the control strategy to control the cooling water. The process of obtaining the spindle's operating status includes: The spindle's working status is obtained according to the preset machining program; The working status includes normal processing status or temporary shutdown status; The control strategy for the three-way flow divider valve, which controls the flow rate of the three-way flow divider valve according to the operating state, includes: If the working state is a normal processing state, then a first control strategy is generated; If the operating state is a temporary shutdown state, then a second control strategy is generated; The corresponding three-way diverter valve opening is obtained by querying the preset three-way diverter valve opening mapping table according to the first control strategy or the second control strategy. Also includes: Identify the processing time points corresponding to temporary shutdown nodes based on the preset processing program; The control parameters of the water chiller are pre-adjusted at a preset time point before the processing time point, and the operation of the water chiller is controlled according to the control parameters. Adjust the three-way diverter valve according to the processing time point and the opening degree of the three-way diverter valve corresponding to the second control strategy; Also includes: Acquire historical ambient temperature, historical spindle load, historical spindle speed, historical spindle running time, and corresponding historical heat generation within a preset historical time period; The initial spindle heating prediction model is trained based on the historical ambient temperature, historical spindle load, historical spindle speed, historical spindle running time, and corresponding historical heat generation to obtain a trained spindle heating prediction model. The real-time ambient temperature, real-time spindle load, real-time spindle speed, and real-time spindle running time are acquired and input into the spindle heating prediction model for processing to obtain the real-time predicted heat generation. The real-time predicted heat generation is compared with the preset heat generation control threshold; If the real-time predicted heat generation is less than the preset heat generation control threshold, then normal execution will proceed; If the real-time predicted heat generation is greater than or equal to the preset heat generation control threshold, the control parameters of the water chiller are adjusted.

2. The spindle water-cooled machine control method for high-precision CNC machine tools according to claim 1, characterized in that, Also includes: Obtain the real-time flow rate and pressure of the bypass circuit in the three-way diverter valve; The real-time traffic flow is compared with the preset nominal traffic flow to obtain the traffic attenuation rate; The real-time pressure is compared with the preset nominal pressure to obtain the pressure decay rate; The bypass loop anomaly index is obtained by weighted summation of the flow rate attenuation rate and the pressure attenuation rate. The bypass circuit anomaly index is compared with a preset bypass circuit anomaly threshold. If the bypass circuit abnormality index is less than the preset bypass circuit abnormality threshold, the bypass circuit is determined to be normal. If the bypass circuit abnormality index is greater than or equal to the preset bypass circuit abnormality threshold, the bypass circuit is determined to be abnormal.

3. A spindle water-cooled machine control system for high-precision CNC machine tools, characterized in that, The device includes a memory and a processor, wherein the memory contains a program for the spindle water-cooled machine control method for high-precision CNC machine tools according to any one of claims 1-2, and the processor executes the program for the spindle water-cooled machine control method for high-precision CNC machine tools.

4. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a spindle water-cooled machine control method program for high-precision CNC machine tools. When the spindle water-cooled machine control method program for high-precision CNC machine tools is executed by a processor, it implements the steps of the spindle water-cooled machine control method for high-precision CNC machine tools as described in any one of claims 1 to 2.

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