A drill bit cooling control method based on cooling temperature data

Abstract

The application discloses a drill bit cooling control method based on cooling temperature data and relates to the technical field of cooling control of drilling equipment. The method is executed by an embedded controller connected with a handheld drilling equipment, and cooling liquid temperature data, cooling liquid supply data and drill bit operation data in a drilling process are acquired. When it is determined that a drilling state is stable according to the drill bit operation data, the cooling liquid supply amount is adjusted, and a target cooling control scheme matched with a current drilling working condition is determined according to the cooling liquid temperature data, the cooling liquid supply data and the drill bit operation data before and after the adjustment. The cooling liquid supply is adjusted according to the target cooling control scheme, and a drill bit driving motor is controlled or an operation prompt is output to an operator. The application can make the drill bit cooling control adapt to the current drilling working condition, and improve the cooling liquid supply adjustment and the drill bit protection timing.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment cooling control technology, and more specifically, to a drill bit cooling control method based on cooling temperature data. Background Technology

[0002] When drilling equipment drills into materials such as concrete and stone, the operator applies axial thrust by holding the control part, the drill bit drive motor drives the drill bit to rotate and cut, and coolant is supplied to the cutting area of ​​the drill bit through the coolant supply device to reduce the temperature of the drill bit and remove drill cuttings.

[0003] In the prior art, CN113818812B discloses a roller cone drill bit with temperature monitoring and cooling functions. This solution uses a temperature sensor and a speed sensor to monitor the drill bit status, and controls the water spray assembly to spray coolant onto the roller cone based on the detection results, thereby achieving temperature monitoring and cooling during the drilling process.

[0004] In actual handheld drilling, the axial thrust applied by the operator, the material being drilled, the drilling depth, and the state of the coolant supply channel will change. Existing drill bit cooling control typically relies on fixed coolant supply parameters, the current drill bit temperature, or the drill bit speed. It fails to adjust the coolant supply under comparable drilling conditions, and it doesn't determine a cooling control scheme that matches the current drilling conditions based on coolant temperature and supply data before and after adjustment. Under different drilling conditions, the controller struggles to promptly determine whether to adjust the coolant supply, limit the drill bit drive motor, or provide operational prompts to the operator. This can easily lead to insufficient coolant supply, unnecessarily increased supply, or delayed drill bit protection.

[0005] Therefore, it is necessary to provide a drill bit cooling control method based on cooling temperature data, so that the cooling control scheme can adapt to the current drilling conditions and improve the regulation of coolant supply and the timing of drill bit protection. Summary of the Invention

[0006] To overcome the shortcomings of existing handheld drilling equipment that primarily rely on fixed fluid supply parameters or single operating data for cooling control, making it difficult to determine a suitable cooling control scheme based on the current drilling conditions, this invention provides a drill bit cooling control method based on cooling temperature data. The method is executed by an embedded controller connected to the handheld drilling equipment. By acquiring coolant temperature data, coolant supply data, and drill bit operating data during the drilling process, the coolant supply is adjusted when the drilling state is determined to be stable based on the drill bit operating data. A target cooling control scheme matching the current drilling conditions is determined based on the coolant temperature and supply data before and after the adjustment. The coolant supply is adjusted according to the target cooling control scheme, the drill bit drive motor is controlled, or operating prompts are output to the operator, thereby improving the adaptability of drill bit cooling control to the current drilling conditions.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A drill bit cooling control method based on cooling temperature data, the method being executed by an embedded controller connected to a handheld drilling device, comprising: acquiring coolant temperature data, coolant supply data, and drill bit operation data during the drilling process; when the drilling state is determined to be stable based on the drill bit operation data, adjusting the coolant supply, and determining a target cooling control scheme matching the current drilling conditions based on the coolant temperature data, coolant supply data, and drill bit operation data before and after adjustment; adjusting the coolant supply according to the target cooling control scheme, and controlling the drill bit drive motor or outputting operation prompts to the operator.

[0009] In a preferred embodiment, acquiring coolant temperature data, coolant supply data, and drill bit operation data during the drilling process, and determining the stability of the drilling state based on the drill bit operation data, includes: the coolant temperature data including coolant inlet temperature and outlet temperature; the coolant supply data including target flow rate, actual flow rate, supply pressure, and liquid arrival status; the drill bit operation data including drill bit speed and propulsion status, and one or more of drive motor current, spindle torque, axial propulsion force, propulsion speed, and drill bit axial displacement, with the drilling load determined based on at least one of the drive motor current, spindle torque, and axial propulsion force; aligning the coolant temperature data, coolant supply data, and drill bit operation data according to a control cycle to form a synchronous data window; determining the most recent effective stable data window from the synchronous data window prior to the current judgment time, using the effective stable data window as a reference window, with the latest control cycle being judged not participating in the reference value calculation of the reference window; and determining that the drilling state is stable when the drill bit speed and drilling load are within their respective stable ranges, and the propulsion status remains stable based on the drill bit operation data, and this stability confirmation time is continuously reached.

[0010] In a preferred embodiment, adjusting the coolant supply includes: determining a basic target flow rate based on drill bit specifications, drilled material, drilling direction, coolant inlet temperature, and supply system configuration; increasing the basic target flow rate to a trial target flow rate when the drilling state is stable, the drill bit is not in a high-temperature dangerous state, the supply pressure is below the safety upper limit, and the supply actuator has adjustment margin, wherein the supply actuator includes a supply pump and a flow regulating component; during a single coolant supply adjustment process, only one of the supply pump and the flow regulating component is changed, keeping the state of the flow regulating component unchanged when changing the supply pump, and keeping the output of the supply pump stable when changing the flow regulating component; determining that the trial target flow rate has been executed when the difference between the actual flow rate and the trial target flow rate is not greater than the larger of the repeatability error of the flow detection device and the minimum adjustment amount of the supply actuator, and this continues until the execution confirmation time is reached; maintaining the trial target flow rate, and restoring the coolant target flow rate to the basic target flow rate after the trial holding time is reached.

[0011] In a preferred embodiment, determining a target cooling control scheme matching the current drilling conditions based on the coolant temperature data, coolant supply data, and drill bit operation data before and after adjustment includes: before increasing the target coolant flow rate, acquiring discharge fluid temperature data during a period when the drilling state is stable and the target coolant flow rate remains unchanged, forming a temperature stability window, and determining the original temperature change trend and normal fluctuation range based on the temperature stability window; after increasing the target coolant flow rate, acquiring the actual flow response, supply pressure response, discharge fluid temperature response, and drill bit thermal state response; the drill bit thermal state response includes the direction of change of thermal state category, response time, and data reliability status determined based on the drill bit proximal temperature or indirect judgment results, wherein the response time is calculated from the moment the target coolant flow rate increases until the thermal state category changes and continuously reaches the corresponding state to enter the confirmation time; continuing the original temperature change trend to form a predicted temperature range under the condition that the target coolant flow rate has not increased, and when the discharge fluid temperature continuously deviates from the predicted temperature range, and deviates from the predicted temperature range, the following steps are taken: When the flow rate exceeds the sum of the normal fluctuation range and the repeated measurement error of the discharge fluid temperature detection device, and reaches the temperature response confirmation time, the discharge fluid temperature response is determined to occur. After the coolant target flow rate is restored, a recovery prediction range is formed based on the change trend of the discharge fluid temperature. When the discharge fluid temperature enters the recovery prediction range and continues to reach the temperature recovery confirmation time, temperature recovery is determined. When the discharge fluid temperature exceeds the recovery prediction range in the opposite direction to the temperature recovery direction after temperature recovery, a temperature rebound is determined. Based on the actual flow rate response, the supply pressure response, the discharge fluid temperature response, the drill bit thermal state response, the temperature recovery, and the temperature rebound, a cooling response reference range for the current borehole is established. Based on the comparison results between the corresponding data during the current drilling process and the cooling response reference range, the target cooling control scheme is determined. When the drilling stability condition fails, the test target flow rate is not actually executed, the liquid arrival state is invalid, the temperature stability window is invalid, or a time synchronization anomaly occurs, the corresponding data is not used to determine the target cooling control scheme.

[0012] In a preferred embodiment, establishing the current borehole cooling response reference range includes: saving valid test records according to the borehole depth range. These valid test records include actual flow response time, supply pressure response time, discharge fluid temperature response direction, discharge fluid temperature response time, temperature change amplitude, temperature recovery time, cooling hold time, drill bit thermal state category change direction, drill bit thermal state response time, and data reliability status. The numerical response parameters include actual flow response time, supply pressure response time, discharge fluid temperature response time, temperature change amplitude, temperature recovery time, cooling hold time, and drill bit thermal state response time. The direction of change in liquid temperature response and drill bit thermal state category are used for directional consistency verification. Data reliability status is used to determine whether the corresponding drill bit thermal state response participates in the establishment of the cooling response reference range. When there are three or four sets of valid test records for the same borehole depth range, the minimum to maximum effective values ​​of each numerical response parameter are used to form the corresponding numerical reference range. When there are five sets of valid test records, each numerical response parameter is sorted, and the second smallest to the second largest value after sorting is used to form the corresponding numerical reference range. When there are more than five sets of valid test records, the five most recent sets of valid test records within the current borehole depth range are selected, and the five sets are used to form the reference range. The processing method of valid test records forms a candidate reference range; when the candidate reference range meets the single adjustment boundary and cumulative offset boundary, and the drill bit thermal state is stable, the coolant transfer and heat exchange state is normal, and the relevant data is reliable, it is updated to the current cooling response reference range; otherwise, the original cooling response reference range is retained; after entering an adjacent borehole depth range, the cooling response reference range of the previous borehole depth range is inherited as a temporary reference range, and a verification test is performed; if any numerical response parameter continuously exceeds the temporary reference range and the allowable error and reaches the corresponding deviation confirmation condition, or the change direction of the discharge fluid temperature response or the drill bit thermal state category is different from the temporary reference range, the candidate reference range is updated to the current cooling response reference range; otherwise, the candidate reference range is retained. When the directional reference range corresponding to the current drilling depth range is inconsistent, a new cooling response reference range is established. When the drill bit specifications, fluid supply channel specifications, coolant type, drilled material type, drilling direction, fluid supply system configuration, detection component configuration, and parameter version are all consistent with the historical records, the historical cooling response reference range is used as a temporary reference range and converted into the cooling response reference range for the current drilling depth after the verification test is passed. When the response parameters gradually change along the same direction, the cooling response reference range is updated within the single adjustment boundary and cumulative offset boundary. When the response parameters cross the cooling response reference range and the allowable error, the cooling response reference range is frozen.

[0013] In a preferred embodiment, determining the target cooling control scheme based on the comparison results of relevant data during the current drilling process and the cooling response reference range includes: performing a comprehensive analysis of the drill bit thermal state and a comprehensive analysis of the coolant transfer and heat transfer state in parallel based on the same synchronous data window; the comprehensive analysis of the drill bit thermal state determines the drill bit thermal state based on the drill bit proximal temperature or indirect judgment results, drilling load, drill bit rotation speed, propulsion state, and state duration, and forms a first state boundary parameter set; the comprehensive analysis of the coolant transfer and heat transfer state is based on the target flow rate, actual flow rate, supply pressure, coolant inlet temperature, discharge temperature, liquid arrival state, target flow rate change time, and the... The cooling response reference range determines the coolant transfer and heat exchange state and forms a second state boundary parameter set. The first and second state boundary parameter sets respectively include state category, data reliability state, allowable drilling load, state entry condition, state exit condition, state holding time, allowable transition state set, prohibited transition state set, and recovery condition. The second state boundary parameter set also includes the allowable cooling response time and the coolant supply adjustment range. Neither the drill bit thermal state comprehensive analysis nor the coolant transfer and heat exchange state comprehensive analysis reads the output of the other comprehensive analysis, and neither directly generates the final control command for the coolant supply pump, flow regulation component, drill bit drive motor, or prompt output component.

[0014] In a preferred embodiment, adjusting the coolant supply according to the target cooling control scheme and controlling the drill bit drive motor or outputting operation prompts to the operator includes: determining the state boundaries of the underlying state machine based on the first state boundary parameter set and the second state boundary parameter set; taking the lower permissible drilling load in the two state boundary parameter sets as the permissible drilling load of the underlying state machine, taking the permissible cooling response time in the second state boundary parameter set as the permissible cooling response time of the underlying state machine, taking the longer confirmation time in the two state exit conditions as the state exit confirmation time, taking the intersection of the two permissible transition state sets as the permissible transition state set, and taking the union of the two prohibited transition state sets as the prohibited transition state set; if no new effective state boundary parameter set is formed within the state boundary update cycle in any comprehensive analysis, the corresponding previous effective state boundary parameter set is used; if no new effective state boundary parameter set is formed... When the duration of the boundary parameter group reaches the failure confirmation time, the corresponding comprehensive analysis is determined to be continuously failed; when only one comprehensive analysis is continuously failed, the drilling is restricted; when the current target flow rate is within the fluid supply adjustment range, and the actual flow rate and fluid supply pressure are both effective and within the corresponding allowable range, the current target flow rate is maintained; otherwise, the safe target flow rate is switched and increasing the drilling load is prohibited; when both comprehensive analyses are continuously failed, the feed stop cooling state is entered and a stop propulsion prompt is output; when neither the actual flow rate nor the fluid supply pressure can be confirmed, the drill bit drive motor is stopped and the cooling failure protection state is entered; when there is no common state in the set of allowed transition states, the state that has met the entry conditions and has the highest priority is selected according to the priority order of cooling failure protection state, feed stop cooling state, restricted drilling state, and enhanced cooling state; when none of the above states meet the entry conditions, the current state is maintained and increasing the drilling load is prohibited until a new effective state boundary parameter group is formed.

[0015] In a preferred embodiment, the underlying state machine includes equipment verification state, reference range establishment state, normal drilling state, cooling response check state, enhanced cooling state, restricted drilling state, feed stop cooling state, cooling failure protection state, and recovery observation state, with each state mutually exclusive. Except for the equipment verification state, the priority of the cooling failure protection state, feed stop cooling state, restricted drilling state, enhanced cooling state, cooling response check state, reference range establishment state, recovery observation state, and normal drilling state decreases sequentially. When the drill bit thermal state is characterized by mild heat accumulation or a decrease in effective heat exchange capacity in the coolant transfer and heat exchange state, the enhanced cooling state is entered, increasing the target coolant flow rate and maintaining the current drilling load or prohibiting further increases in the drilling load. When the drill bit thermal state is characterized by continuous heat accumulation, the use of a temporary reference range, or a single comprehensive analysis showing continuous failure, the restricted drilling state is entered, maintaining the current target flow rate or switching to a safe target flow rate, reducing the drill bit speed or allowable torque, and transmitting data to the operator. The system provides the following warnings: Reduce thrust warning; If the drill bit's thermal state is rapidly heating up or at a dangerous high temperature, both comprehensive analyses remain ineffective, or the restricted drilling state reaches its maximum holding time without meeting the exit conditions, enter the stop-feed cooling state, output a stop-feed warning, and reduce the drill bit speed or allowable torque; In the stop-feed cooling state, if the actual flow rate and supply pressure are both effective and within their respective allowable ranges, maintain the safe target flow rate and output a retraction warning; If the operator does not stop the feed, the drilling load exceeds the current allowable drilling load, or the drill bit drive motor experiences overcurrent, stop the drill bit drive motor; If the stop-feed cooling state reaches its maximum holding time without meeting the exit conditions, or if the actual flow rate and supply pressure cannot be confirmed, enter the cooling failure protection state; The recovery observation state includes a first recovery level and a second recovery level. When the drill bit's thermal state and coolant transfer and heat exchange state both meet the corresponding recovery conditions and reach the corresponding holding time, the allowable drilling load is gradually increased; When the second recovery level is completed and no temperature rebound occurs, enter the normal drilling state.

[0016] In a preferred embodiment, the drill bit thermal state is obtained through direct detection or indirect judgment. Direct detection determines the drill bit thermal state based on the drill bit proximal temperature, the direction of temperature change, and the duration of the change. Indirect judgment determines the drill bit thermal state and data reliability based on the coolant inlet temperature, outlet temperature, drilling load, drill bit rotation speed, propulsion status, and drilling duration, using a calibration data table corresponding to the drill bit specifications. A new valid data is obtained if the drill bit proximal temperature continuously exceeds the range, exhibits abnormal fluctuations, or shows an invalid reading, reaching the direct detection failure confirmation time, or if the sum of the temperature sampling period and the allowable communication delay is exceeded without obtaining a new valid reading. When sampling values, it is determined that the direct detection method is invalid; when the direct detection method is invalid, and the data required by the indirect judgment method and the calibration data table are valid, switch to the indirect judgment method and enter the restricted drilling state; when the drill bit proximal temperature is continuously valid, changes continuously, and does not have a continuous inconsistency with the result of the indirect judgment method, and the direct detection recovery confirmation time is reached, the direct detection method is re-adopted after recovery observation; when neither the direct detection method nor the indirect judgment method can form a reliable drill bit thermal state, a stop propulsion prompt is output; when both the actual flow rate and the fluid supply pressure are invalid, the drill bit drive motor is stopped and enters the cooling failure protection.

[0017] A drill bit cooling control device includes a processor, a memory, a data acquisition interface, and a control output interface. The data acquisition interface is used to connect to a coolant temperature detector, a flow rate detector, a pressure detector, a liquid arrival detector, and a drill bit operation detection interface. The control output interface is used to connect to a liquid supply pump, a flow regulation component, a drill bit drive motor, and a prompt output component. The memory stores a drill bit cooling control program, which, when executed by the processor, enables the drill bit cooling control device to implement the aforementioned drill bit cooling control method.

[0018] The technical effects and advantages of the drill bit cooling control method based on cooling temperature data of the present invention are as follows:

[0019] This invention acquires synchronous data such as coolant inlet temperature, outlet temperature, actual flow rate, supply pressure, drill bit speed, propulsion status, and drilling load. During periods when the drilling load remains stable, it implements a process of increasing and restoring coolant supply. Based on the actual flow rate response, pressure response, temperature response, and restoration status, it establishes a reference range for the cooling response of the current borehole, thereby improving the adaptability of cooling control to changes in drill bit specifications, drilled materials, borehole depth, and operating conditions.

[0020] This invention helps to distinguish between situations such as increased drill bit heat generation, abnormal coolant supply execution, delayed coolant arrival, and decreased heat exchange capacity by performing parallel comprehensive analysis of drill bit thermal state and coolant transfer and heat exchange state. It also forms boundary parameters of the underlying state machine for each situation, reducing misjudgments caused by adjusting only a single temperature or fixed fluid supply parameters.

[0021] This invention uses a bottom-level state machine to uniformly determine states such as normal drilling, enhanced cooling, restricted drilling, feed stop cooling, cooling failure protection, and recovery observation. It also outputs coolant supply, speed limit, drilling load control, stop propulsion prompt, retraction prompt, and abnormal protection results, which helps to improve the accuracy, adaptability, and safety of drill bit cooling control. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the application scenario of the handheld drilling equipment and coolant supply of the present invention.

[0023] Figure 2 This is a cross-sectional view of the structure for collecting and detecting the temperature of the returned liquid and the discharged liquid in this invention.

[0024] Figure 3 This is a diagram illustrating the architecture of the embedded drill bit cooling control device, data interface, and control interface of the present invention.

[0025] Figure 4 This is a flowchart of the overall process of the drill bit cooling control method based on cooling temperature data according to the present invention.

[0026] Figure 5 This is a schematic diagram illustrating the multi-source data time alignment and drilling status stability determination of the present invention.

[0027] Figure 6 This is a flowchart illustrating the switching process between direct detection and indirect judgment of the thermal state of the drill bit in this invention.

[0028] Figure 7 This is a time-series diagram showing the adjustment of coolant supply and the changes in data before and after adjustment in this invention.

[0029] Figure 8 This diagram illustrates the establishment, verification, and updating of the current borehole cooling response reference range for this invention.

[0030] Figure 9 This is a schematic diagram illustrating the two comprehensive analyses and the underlying state machine control relationships of this invention.

[0031] Figure 10 This is the state transition diagram of the underlying state machine of this invention.

[0032] Figure 11 This is a flowchart illustrating the data degradation, inconsistent analysis results, and protection against special operating conditions in this invention.

[0033] 100. Drilling equipment; 110. Drill bit; 120. Drill barrel or drill rod; 130. Drill bit drive unit; 140. Handheld operating unit; 150. Material to be drilled; 160. Drill hole; 200. Coolant supply device; 210. Supply pump; 220. Supply pipeline; 230. Flow regulating component; 240. Supply channel; 310. Inlet temperature sensor; 320. Outlet temperature sensor; 330. Flow sensor; 340. Pressure sensor; 350. Drill bit proximal end temperature sensor; 400. Return fluid collection structure; 410. Temperature detection space; 420. Liquid arrival detection component. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0035] This invention provides a drill bit cooling control method based on cooling temperature data, applicable to handheld water drills, handheld core drills, and other rotary drilling equipment 100 that have a coolant supply function and allow the operator to directly apply axial thrust. The coolant can be water or a water-based coolant suitable for the drill bit 110 and the material being drilled 150.

[0036] In this embodiment, the advancing state refers to the state formed when the operator applies an axial advancing force in the direction of the borehole 160 through the hand-held operating part 140; stopping advancing means that the operator stops applying the axial advancing force; the retraction prompt is used to prompt the operator to move the drilling equipment 100 in the opposite direction of the borehole 160 so that a coolant flow space is formed between the cutting area of ​​the drill bit 110 and the hole wall.

[0037] This method is executed by an embedded controller connected to the drilling equipment 100. The embedded controller includes a processor, memory, a data acquisition interface, and a control output interface. The embedded controller can control the fluid supply pump 210, the flow regulation component 230, and the drill bit drive motor, and output prompts to the operator to reduce the thrust, stop the thrust, or retract the drill bit via the prompt output component. The embedded controller does not actively generate axial thrust or retraction movements of the drill bit 110. External devices connected to the embedded controller can be used for parameter calibration, version management, and export of operation records, but do not participate in real-time cooling control.

[0038] like Figure 3 and Figure 4 As shown, this method includes four interconnected processing steps.

[0039] The first step is to acquire coolant temperature data, coolant supply data, and drill bit operation data during the drilling process, time-align the data from different sampling frequencies, and determine the time period when the drilling status is stable.

[0040] The second step involves increasing the base target flow rate to the test target flow rate during a period of stable drilling, maintaining this level, and then restoring it to the base target flow rate. This process yields the actual flow rate, supply pressure, discharge fluid temperature, and drill bit thermal status response, and establishes a reference range for the current borehole cooling response.

[0041] The third step involves performing parallel comprehensive analyses of the drill bit's thermal state and coolant transfer and heat exchange states, based on the same synchronized data window, to generate a first state boundary parameter set and a second state boundary parameter set, respectively. Neither comprehensive analysis reads the output of the other, nor does it directly generate the final control command for the actuator.

[0042] The fourth step is to determine the state boundaries of the bottom-level state machine based on the first state boundary parameter group and the second state boundary parameter group. The bottom-level state machine then outputs the coolant supply, drill bit speed, allowable torque, operation prompts, and abnormal protection results.

[0043] Example 1 illustrates the drilling equipment, data acquisition, stability assessment of drilling status, and coolant supply testing.

[0044] like Figure 1 As shown, the drilling equipment 100 includes a drill bit 110, a drill barrel or drill rod 120, a drill bit drive unit 130, and a handheld operating unit 140. The drill bit drive motor in the drill bit drive unit 130 drives the drill barrel or drill rod 120 and the drill bit 110 to rotate via a spindle. The operator pushes the drill bit 110 towards the borehole 160 in the material being drilled 150 via the handheld operating unit 140.

[0045] The coolant supply device 200 includes a water source or storage container, a supply pump 210, a supply pipeline 220, and a flow regulating component 230. The supply pipeline 220 is connected to a supply channel 240 inside or around the drill barrel or drill rod 120, and the supply channel 240 extends to a position near the cutting end of the drill bit 110.

[0046] The inlet temperature sensor 310 is installed in the liquid supply line 220 downstream of the flow regulating component 230. The flow sensor 330 and the pressure sensor 340 are used to obtain the actual flow rate and liquid supply pressure, respectively.

[0047] The drill bit proximal temperature sensor 350 is located in the exposed area of ​​the drill barrel or drill rod 120 near the borehole opening. Preferably, the drill bit proximal temperature sensor 350 is a fixed non-contact temperature sensor, fixed to the housing or independent bracket of the return fluid collection structure 400, with its detection direction facing the exposed surface of the drill barrel or drill rod 120, and the detection area avoiding the area directly flushed by the discharged fluid. The mounting bracket of the sensor adopts a vibration-damping connection, and the temperature sensing window is equipped with a cleanable protective plate. If water film or drill cuttings continuously obstruct the detection area, vibration causes the temperature data to exceed the abnormal jump boundary, the measured value exceeds the range, or no new valid sampling value is continuously obtained, the drill bit proximal temperature data is marked as invalid.

[0048] like Figure 2 As shown, a return fluid collection structure 400 is provided near the borehole opening. The return fluid collection structure 400 includes a return fluid inlet, a settling space, a sampling channel, a temperature detection space 410, and a discharge outlet. The sampling channel is equipped with a chip-blocking structure, and the temperature detection space 410 is equipped with a detachable cleaning structure. A discharge fluid temperature sensor 320 is located within the temperature detection space 410, and a liquid arrival sensor 420 is located before the discharge fluid enters the effective temperature sensing area of ​​the discharge fluid temperature sensor 320. When the liquid arrival status is invalid, the corresponding discharge fluid temperature data is not used to form a deterministic temperature response, nor is it used to establish a cooling response reference range.

[0049] Coolant temperature data includes coolant inlet temperature and outlet temperature. Coolant supply data includes target flow rate, actual flow rate, supply pressure, and fluid arrival status. Drill bit operation data includes drill bit 110 rotational speed and propulsion status, as well as one or more of the following: drive motor current, spindle torque, axial propulsion force, propulsion speed, and drill bit 110 axial displacement.

[0050] Drilling load is determined based on at least one of the drive motor current, spindle torque, and axial thrust. When using two or more detection quantities, each quantity is used separately to judge changes in drilling load. Drilling load stability is confirmed when all valid critical detection quantities are within their corresponding stable ranges; drilling instability is confirmed when any critical detection quantity exceeds its corresponding abnormal boundary; in case of inconsistent detection results, the result with the higher level of protection is adopted. When a single non-critical detection quantity fails, a downgrade judgment is performed based on the remaining valid detection quantities, and updating the baseline window and cooling response reference range is prohibited. Critical detection quantities are determined based on the current detection configuration and parameter version.

[0051] Temperature data can be sampled at a frequency of 5 to 20 times per second, flow and pressure data at 20 to 100 times per second, and drive motor current data at 100 to 1000 times per second. The embedded controller performs time alignment on the data according to a control cycle of 50 to 200 milliseconds, forming a synchronized data window that includes start and end times, data source identifiers, valid status, and parameter versions. When the data time deviation exceeds the time window corresponding to the current control cycle, the corresponding data is marked as a time synchronization anomaly.

[0052] After the equipment is powered on, reset, drill bit 110 is replaced, fluid supply line 220 is reconnected, or the fault is cleared, online checks of test components, low-flow fluid supply checks, and no-load operation checks are performed. The low-flow fluid supply check confirms whether the actual flow rate and fluid supply pressure change within the corresponding response time in accordance with the calibration relationship. The no-load operation check obtains the no-load speed, no-load current, and their fluctuation range. The equipment calibration duration can be from 10 to 60 seconds. If the calibration times out, fluid supply execution cannot be confirmed, or key test data becomes invalid, the equipment enters a cooling failure protection state.

[0053] like Figure 5 As shown, the embedded controller selects the most recent valid stable data window from the synchronous data window prior to the current judgment time as the reference window. The latest control cycle being judged is not included in the reference value calculation. When the drill bit 110 speed is within 3% to 5% of the reference average, the drive motor current or spindle torque is within 5% to 8% of the reference average, and the feed speed is within 5% to 10% of the reference average, and the feed state remains stable for 0.5 to 2 seconds, the drilling state is determined to be stable.

[0054] When no propulsion speed detection device is set, the propulsion status is determined based on valid data from axial propulsion force, drive motor current, spindle torque, and drill bit 110 rotation speed. The stable range and stable confirmation time are calibrated through stable propulsion, gradual increase of propulsion force, sudden decrease of propulsion force, rebar cutting, drill bit 110 jamming, and manual retraction tests, and saved in accordance with the drill bit 110 specifications, detection configuration, and parameter version. When manual retraction, rebar cutting, jamming, target flow adjustment, or sudden changes in actual base flow occur, the reference window is frozen; if no historical valid window exists, the corresponding conservative factory stable range is adopted.

[0055] The basic target flow rate is determined from the basic fluid supply parameter table based on the drill bit 110 specification, drilled material 150, borehole 160 direction, coolant inlet temperature, and fluid supply system configuration. The basic fluid supply parameter table is established through normal drilling tests. Starting from the manufacturer's recommended minimum cooling flow rate or the equipment's lowest fluid supply setting, the fluid supply is gradually increased. When the fluid reaches an effective state, the supply pressure is below the safety limit, the drill bit's thermal state is stable, and drill cuttings can be continuously discharged, the corresponding minimum actual flow rate is determined as the minimum stable cooling flow rate, and a safety margin of 5% to 15% is added to form the basic target flow rate. If matching parameters cannot be obtained, a conservative factory target flow rate is used, limiting the drill bit 110 speed or allowable torque, and a reduced thrust warning is output.

[0056] The safety target flow rate is used for trial termination, data degradation, recovery observation, and protection. When the fluid supply channel 240 is in normal condition and the drill bit's thermal condition deteriorates, the safety target flow rate can be 100% to 120% of the basic target flow rate. When the fluid supply pressure increases or the resistance of the fluid supply channel 240 increases, the safety target flow rate is gradually reduced in increments of 5% to 10% of the basic target flow rate. If the actual flow rate cannot reach the target value and the fluid supply pressure does not increase, the output of the fluid supply pump 210 is increased or the opening of the flow regulating component 230 is increased, maintaining at least one corresponding response time after each adjustment. If the fluid supply pressure still does not recover after reducing to the minimum stable cooling flow rate, or if the actual flow rate still cannot be confirmed after the fluid supply actuator reaches its output limit, the system enters protection mode. If upstream waterlessness, fluid supply line 220 rupture, serious leakage, waterless running, or serious electrical fault is detected, the safety target flow rate is set to zero and the drill bit drive motor is stopped.

[0057] When the drilling is stable, the drill bit 110 is not in a high-temperature dangerous state, the fluid supply pressure is lower than the safety limit and the fluid supply actuator has an adjustment margin, increase the basic target flow rate by 8% to 20% to form the test target flow rate, maintain it for 0.5 to 2.5 seconds and then restore it to the basic target flow rate. After restoration, observe for 1 to 5 seconds. The interval between two adjacent tests is 5 to 30 seconds.

[0058] Each trial involves changing only one of the liquid supply pump 210 and the flow regulating component 230. When changing the output of the liquid supply pump 210, the state of the flow regulating component 230 remains unchanged; when changing the opening degree of the flow regulating component 230, the output of the liquid supply pump 210 remains stable.

[0059] The minimum adjustment amount of the liquid supply actuator is represented by the smallest identifiable change in actual flow rate that can be achieved after the action. When the difference between the actual flow rate and the target flow rate is no greater than the larger of the repeatability error of the flow sensor 330 and the minimum adjustment amount of the liquid supply actuator, and this difference is maintained continuously for 2 to 5 control cycles, the target flow rate is confirmed to have been achieved. If the achievement confirmation condition is not met, the current test is terminated and the flow rate is restored to the safe target flow rate.

[0060] The initial response reference time is preferably determined according to the following formula:

[0061] ;

[0062] in, Indicates the initial response reference time; This indicates the effective fluid supply volume between the downstream of the flow regulating component 230 and the coolant outlet in the cutting area of ​​the drill bit 110; This represents the average volumetric flow rate detected during the trial liquid supply period; This indicates the coolant return time as it passes through the borehole area and flows to the temperature detection space 410. This indicates the time required for the discharge liquid temperature detection element 320 to reach the specified response ratio.

[0063] The effective fluid supply volume is calculated based on the structural dimensions of the fluid supply channel 240 or obtained through quantitative fluid injection. The return fluid transfer time is obtained through a low-load fluid supply test. After obtaining the effective field response of the current borehole, the field response time range is used to replace the initial response reference time.

[0064] If the following occurs during the test: drilling instability, drill bit 110 entering a high-temperature dangerous state, the test target flow rate not being actually executed, the fluid supply pressure exceeding the safety limit, the fluid supply actuator reaching the output limit, the fluid arrival status being invalid, or the detection communication being interrupted or a manual emergency stop is performed, the test will be terminated, the corresponding record will be marked as invalid, and the basic target flow rate will be restored, switched to the safe target flow rate, or the protection state will be entered, depending on the degree of abnormality.

[0065] Example 2 illustrates the extraction of cooling response, the establishment of cooling response reference range, and the determination of target cooling control scheme.

[0066] like Figure 7 As shown, before increasing the target coolant flow rate, a temperature stabilization window is formed by selecting 1 to 3 seconds of effective discharged fluid temperature data within a period of stable drilling conditions and unchanged target flow rate. The original temperature trend is determined based on the initial, final, and duration of the temperature within the window. The normal fluctuation range is the larger of the maximum deviation of the discharged fluid temperature from the original temperature trend and the repeatability error of the discharged fluid temperature sensor 320. If a change in target flow rate, instability in drilling conditions, invalid fluid arrival status, or communication anomalies occur within the temperature stabilization window, the window is marked as invalid.

[0067] The instantaneous abrupt change boundary is determined based on the repeatability error of the discharge fluid temperature sensor 320 and the maximum normal variation of adjacent valid sampled values ​​during stable drilling. If a single sampled value exceeds the instantaneous abrupt change boundary, and the subsequent valid sampled value returns to the normal fluctuation range, that sampled value is excluded. A change in temperature change trend is confirmed when two to five consecutive new valid sampled values ​​deviate from the normal fluctuation range in the same direction. Trend judgment can be based on the median or moving average of three to five consecutive sampled values.

[0068] After the target coolant flow rate is increased, the actual flow rate response, supply pressure response, discharge fluid temperature response, and drill bit thermal state response are acquired. The actual flow rate response time and supply pressure response time are both calculated from the moment the target flow rate changes, and continue until the actual flow rate or supply pressure consistently exceeds the pre-adjustment fluctuation range and reaches the response confirmation time. When the actual flow rate reaches the allowable range corresponding to the trial target flow rate, while the supply pressure remains within the pre-adjustment fluctuation range, the supply pressure response is recorded as the pressure stabilization response, and the actual flow rate execution confirmation time is recorded as its response time.

[0069] The embedded controller determines the original temperature change rate based on the difference between the first and last effective temperatures within the temperature stability window and the corresponding time difference. When there are instantaneous abrupt changes in sampled values, abnormal sampled values ​​are first excluded. Starting with the effective discharge liquid temperature at the moment the target flow rate increases, the reference temperature for subsequent sampling moments is extrapolated according to the original temperature change rate. The normal fluctuation range is then superimposed on both sides of the reference temperature to form the expected temperature range under the condition that the target flow rate does not increase.

[0070] When the discharge fluid temperature continuously deviates from the expected temperature range, exceeding the sum of the normal fluctuation range and the repeated measurement error of the discharge fluid temperature sensor 320, and maintains this deviation for 2 to 5 consecutive valid new sample values, a discharge fluid temperature response is confirmed. When initially establishing a cooling response reference range, record the actual direction of the discharge fluid temperature response, without pre-defining its increase or decrease.

[0071] After the coolant target flow rate is restored, the effective discharge temperature at the time of restoration is used as the starting point. Based on 2 to 5 consecutive effective new sampled values ​​after restoration, the direction and rate of temperature recovery are determined, and a recovery prediction range is formed. Temperature recovery is confirmed when the discharge temperature enters the recovery prediction range and continues to reach the temperature recovery confirmation time; temperature rebound is confirmed when the temperature exceeds the recovery prediction range in the opposite direction after restoration.

[0072] The drill bit thermal state response includes the direction of change in thermal state category, the drill bit thermal state response time, and the data reliability status. The drill bit thermal state response time is calculated from the moment the target coolant flow rate is increased until the drill bit thermal state category changes and remains at the corresponding state until confirmation. If a reliable drill bit thermal state cannot be formed, the drill bit thermal state response time is not recorded. The cooling hold time is the time from when the drill bit thermal state enters the cooling recovery phase until it re-enters the heat accumulation state or returns to a steady state.

[0073] A valid test record should include at least the following: drill bit specification 110, drilled material 150, borehole depth range 160, basic target flow rate, test target flow rate, basic actual flow rate, test actual flow rate, actual flow rate response time, fluid supply pressure response status and response time, discharge fluid temperature response direction, discharge fluid temperature response time, temperature change amplitude, temperature recovery time, cooling hold time, temperature rebound status, drill bit thermal state category change direction, drill bit thermal state response time and data reliability status.

[0074] like Figure 8 As shown, when no valid on-site response has been obtained, the conservative factory range corresponding to the 110 drill bit specification is used to limit the testing and trigger protection. When 3 or 4 sets of valid test records are obtained in the same borehole depth range, the corresponding range is formed by the minimum to the maximum valid value of each numerical response parameter; when 5 sets of valid test records are obtained, the corresponding range is formed by the second smallest to the second largest value after sorting.

[0075] When there are more than 5 valid test records, the 5 most recent valid test records within the current borehole depth range are selected to form a candidate reference range. If the candidate reference range meets the single adjustment boundary and cumulative offset boundary, and the drill bit thermal state is stable, cooling transfer is normal, and relevant data is reliable, it is updated to the current cooling response reference range; otherwise, the original cooling response reference range is retained. Records with consistent response directions form a directional benchmark; records with inconsistent directions are used for anomaly checks and are not included in the numerical range establishment.

[0076] The drilling depth range can be divided into 10 mm to 50 mm, or into 0.5 to 2 times the diameter of the drill bit 110. The length of the range is determined based on the drill bit diameter, the uniformity of the drilled material 150, the drilling direction, and the depth detection accuracy.

[0077] Upon entering an adjacent depth interval, the cooling response reference range of the previous depth interval is inherited as a temporary reference range, and one to two verification tests are performed. The allowable error is the maximum value among the repeated measurement error of the test piece, the control response error, and the width of the original response range (5% to 15%). If the same response parameter exceeds the temporary reference range and allowable error twice consecutively in the same direction, or if the direction of the discharge fluid temperature response or the direction of change of the drill bit thermal state category is inconsistent with the corresponding directional reference, the cooling response reference range for the current depth interval is re-established.

[0078] When referencing historical cooling response reference ranges, the drill bit specification (110), fluid supply channel specification (240), coolant type, drilled material category (150), drilling direction, fluid supply system configuration, sensor configuration, and parameter version must be consistent. Historical ranges are initially used as temporary reference ranges and, after successful verification, are converted to the current cooling response reference range.

[0079] The cooling response reference range is updated only when the drill bit's thermal condition is stable, cooling transfer is normal, the depth range has not switched, relevant data is valid, and there are no time synchronization anomalies. A single adjustment should not exceed 5% to 10% of the original response range width, and the cumulative offset should not exceed 20% to 50% of the initial response range width. If the cumulative offset limit is reached, or if the response parameters directly cross the original response range and allowable error, the cooling response reference range is frozen and the system enters a cooling response check state.

[0080] The embedded controller compares the current response with a cooling response reference range. When the actual flow rate, supply pressure, and discharge temperature responses are all within their respective ranges, the base target flow rate and current drilling load are maintained. If the actual flow rate is insufficient and the supply pressure does not increase, the output of the supply pump 210 is increased or the opening of the flow regulation component 230 is increased; if the supply pressure increases but the actual flow rate does not increase accordingly, further increases in the supply rate are prohibited, and drilling is restricted.

[0081] When the actual flow rate increases but the fluid arrival status is invalid, the discharge fluid temperature data is marked as invalid, and drilling is restricted. When the actual flow rate, supply pressure, and discharge fluid temperature response are all within the corresponding range, but the drill bit thermal condition improvement is insufficient, the effective heat exchange capacity decreases or the drilling heat generation exceeds the current cooling capacity, depending on the drilling load.

[0082] If the direction of the discharged fluid temperature response is inconsistent with the direction reference recorded in the cooling response reference range, or if the discharged fluid temperature response time or temperature change amplitude continuously exceeds the cooling response reference range and allowable error, the discharged fluid temperature response is determined to be abnormal. When the abnormal discharged fluid temperature response reaches the confirmation time, and the drill bit's thermal state is characterized by rapid temperature rise or high-temperature danger, the conditions for entering the stop-feed cooling state are met. If more than two temperature rebounds are confirmed during the same recovery observation period, the stop-feed cooling state is entered.

[0083] When the liquid arrival status remains valid, the actual flow rate and supply pressure have recovered to the corresponding allowable range, the drill bit's thermal state is stable or has cooled down and recovered, and the temperature recovery time of the discharged liquid after the target flow rate recovery exceeds the upper limit of the cooling response reference range and the allowable error, and reaches the retention confirmation time, it is determined that the return channel is stuck. The retention confirmation time is determined through normal drainage and drainage obstruction tests, and is saved in accordance with the configuration and parameter version of the return collection structure 400.

[0084] Example 3 illustrates two parallel synthesis analyses, state boundary merging, analysis anomaly handling, and the underlying state machine.

[0085] like Figure 9 As shown, within each control cycle, the embedded controller performs a comprehensive analysis of the drill bit's thermal state and a comprehensive analysis of the coolant transfer and heat exchange state in parallel based on the same synchronous data window.

[0086] The drill bit thermal status comprehensive analysis reads the drill bit proximal temperature or indirectly determines the drilling load, drill bit rotation speed (110), propulsion status, and status duration. The coolant transfer and heat exchange status comprehensive analysis reads the target flow rate, actual flow rate, supply pressure, coolant inlet temperature, discharge temperature, liquid arrival status, target flow rate change time, and current cooling response reference range. Neither comprehensive analysis reads the output of the other comprehensive analysis, nor does it directly generate final control commands for the supply pump 210, flow regulation component 230, drill bit drive motor, or prompt output component.

[0087] The two comprehensive analyses respectively form the first state boundary parameter set and the second state boundary parameter set. Both parameter sets include generation time, applicable drill bit size 110, applicable depth range, parameter version, state category, data reliability status, allowable drilling load, state entry conditions, state exit conditions, state holding time, allowable state transition set, prohibited state transition set, and recovery conditions; the second state boundary parameter set also includes the allowable cooling response time and fluid supply adjustment range.

[0088] Drill bit thermal states include stable, mild heat accumulation, continuous heat accumulation, rapid temperature rise, high temperature danger, cooling recovery, and unreliable data.

[0089] If the near-end temperature of the drill bit or the indirect assessment result continues to rise for more than the first duration and the drilling load does not decrease, it is determined to be mild heat accumulation; if it continues to rise for more than the second duration, or if the cooling hold time after enhanced cooling is shortened relative to the cooling response reference range, it is determined to be continuous heat accumulation; if the rate of temperature change exceeds the rapid temperature rise boundary, or if more than two temperature rebounds are confirmed during the same recovery observation period, it is determined to be rapid temperature rise; if the temperature enters the high temperature protection range, or continues to rise after the output of the stop propulsion prompt, it is determined to be high temperature danger.

[0090] The hot state of the drill bit is confirmed by two to five consecutive control cycles, and the exit confirmation time is 1.5 to 3 times the corresponding entry confirmation time. The first duration, the second duration, the rapid temperature rise boundary, and the high temperature protection range are calibrated through normal drilling, gradually increasing thrust, overload drilling, and stopping thrust for cooling tests.

[0091] Coolant transfer and heat exchange status includes normal cooling transfer, delayed coolant arrival, increased resistance in the supply channel, stagnation in the return channel, high inlet temperature, decreased effective heat exchange capacity, abnormal supply execution, drilling heat generation exceeding the current cooling capacity, and unreliable data.

[0092] If the actual flow rate does not increase after the target flow rate is increased, an abnormality in the fluid supply execution is determined, and the cause is further differentiated based on changes in the fluid supply pressure: insufficient upstream fluid supply, unresponsive fluid supply actuators, and increased resistance in the fluid supply channel. If the actual flow rate increases but the fluid arrival status is invalid, a coolant arrival delay is determined, and the discharge fluid temperature is marked as invalid. If the actual flow rate, fluid supply pressure, and discharge fluid temperature response are all within their respective ranges, but the improvement in the drill bit thermal condition is insufficient, and the drilling load is within a stable range, the effective heat exchange capacity is determined to have decreased; if the drilling load exceeds the current allowable range, the drilling heat generation is determined to have exceeded the current cooling capacity.

[0093] like Figure 9 As shown, when merging state boundaries, the lower permissible drilling load in the two state boundary parameter sets is used as the permissible drilling load of the underlying state machine, and the permissible cooling response time in the second state boundary parameter set is used as the permissible cooling response time of the underlying state machine. When both state exit conditions include an exit confirmation time, the longer exit confirmation time is used; the intersection of two permissible transition state sets is used, and the union of two prohibited transition state sets is used.

[0094] If no new valid parameter set is formed within the state boundary update cycle of any comprehensive analysis, the previous valid parameter set is used. When the failure confirmation time is continuously reached, the corresponding comprehensive analysis is confirmed to be continuously failed. If only one comprehensive analysis is continuously failed, drilling is restricted; if the current target flow rate is within the fluid supply adjustment range, and both the actual flow rate and fluid supply pressure are valid and within their respective allowable ranges, the current target flow rate is maintained; otherwise, the safe target flow rate is switched to, and increasing the drilling load is prohibited. If both comprehensive analyses are continuously failed, feed is stopped and cooling is initiated, and a stop-progress warning is output; if neither the actual flow rate nor the fluid supply pressure can be confirmed, the drill bit drive motor is stopped, and cooling failure protection is initiated.

[0095] If the comprehensive analysis of coolant transfer and heat exchange status outputs normal coolant transfer, but the comprehensive analysis of drill bit thermal status outputs continuous heat accumulation, rapid temperature rise, or high-temperature danger, a first inconsistency indicator is formed. If the comprehensive analysis of coolant transfer and heat exchange status outputs abnormal coolant supply execution, delayed coolant arrival, or reduced effective heat exchange capacity, but the comprehensive analysis of drill bit thermal status outputs stable, a second inconsistency indicator is formed.

[0096] Before confirming inconsistencies in the analysis results, a state boundary with a high degree of protection is adopted, and the cooling response reference range is frozen. If the inconsistency in the analysis results persists until the confirmation time, and the drill bit's thermal state is rapidly heating up or at risk of high temperature, it enters a stop-feed cooling state; otherwise, it enters a restricted drilling state. After the two comprehensive analyses continuously return to consistency and the data is reliable, the inconsistency flag is removed through recovery observation. In the event of a high temperature hazard, complete failure of fluid supply, fluid supply pressure exceeding the safety limit, or failure of critical data, it directly enters the corresponding high-priority state.

[0097] When two sets of permissible transition states do not share a common state, the state with the highest priority that has already met the entry conditions is selected, following the priority order of cooling failure protection state, feed stop cooling state, drilling restriction state, and enhanced cooling state. If none of the above states meet the entry conditions, the current state is maintained and increasing the drilling load is prohibited until a new set of valid state boundary parameters is formed. If the fluid supply, drill bit speed of 110 rpm, or drilling load limit results corresponding to the current state cannot be effectively executed within the execution confirmation time, or if continuing to maintain it would cause the drill bit thermal state, fluid supply pressure, or drilling load to exceed the safety boundary, the current state is determined to be unsustainable and a higher priority state is entered.

[0098] like Figure 10 As shown, the bottom-level state machine includes equipment verification state, reference range establishment state, normal drilling state, cooling response check state, enhanced cooling state, limited drilling state, feed stop cooling state, cooling failure protection state, and recovery observation state. These states are mutually exclusive. Except for the equipment verification state, the priority of the cooling failure protection state, feed stop cooling state, limited drilling state, enhanced cooling state, cooling response check state, reference range establishment state, recovery observation state, and normal drilling state decreases in that order. Manual emergency stop and severe electrical faults override the current state output.

[0099] The equipment enters the calibration state after power-on, reset, replacement of drill bit 110, reconnection of liquid supply line 220, or fault resolution. It exits the calibration state after passing the calibration and enters the cooling failure protection state after calibration timeout.

[0100] If an effective cooling response reference range has not yet been established in the current borehole, the system enters a reference range establishment state. This state uses a conservative factory-set range to limit the drill bit speed to 110 rpm and allowable torque, and establishes the current cooling response reference range through effective trial recordings. This state can last for a maximum of 30 seconds to 3 minutes, and the maximum number of invalid trials can be 3 to 5. If an effective range is still not established after reaching either upper limit, the system adopts a conservative factory-set range and enters a restricted drilling state.

[0101] When the cooling response reference range is valid, both state boundary parameter groups are allowed to enter, the drill bit thermal state is stable, and cooling transfer is normal, the system enters the normal drilling state and outputs the basic target flow rate and normal drill bit operating parameters. When verification testing is required or checks are needed after the cooling response reference range has been frozen, the system enters the cooling response check state, prohibiting the increase of drilling load. If the response is normal, the system returns to the normal drilling state; if the response is abnormal, the system enters the enhanced cooling state or the restricted drilling state.

[0102] When the drill bit's thermal state is characterized by slight heat accumulation or a decrease in effective heat transfer capacity of the coolant, it enters an enhanced cooling state. This increases the target coolant flow rate and maintains the current drilling load or prevents further increases in the drilling load. The minimum holding time for the enhanced cooling state is the maximum of the actual flow rate response time, the supply pressure response time, and the drill bit's thermal state entry confirmation time. The maximum holding time can range from 3 to 30 seconds. If the exit conditions are not met even after reaching the maximum holding time, the drill bit enters a restricted drilling state.

[0103] When the drill bit's thermal state involves continuous heat accumulation, the use of a temporary reference range, or a single comprehensive analysis showing persistent failure, it enters a restricted drilling state. This maintains the current target flow rate or switches to a safe target flow rate, reduces the drill bit's 110° rotational speed or allowable torque, and outputs a warning to reduce thrust. If the coolant supply pressure increases or the resistance in the coolant supply channel 240 increases, the target coolant flow rate will not be increased further. The minimum holding time for the restricted drilling state is the maximum of the temperature response allowable time, the drill bit thermal state exit confirmation time, and the drill bit drive control response time; the maximum holding time can be 5 to 60 seconds. If the exit condition is not met even after reaching the maximum holding time, it enters a stop-feed cooling state.

[0104] When the drill bit's thermal state is rapidly rising or at a dangerous high temperature, both comprehensive analyses fail continuously, or the drilling restriction condition is maintained for the maximum time without meeting the exit conditions, the drill bit enters a stop-feed cooling state, outputting a stop-advancement prompt and reducing the drill bit speed to 110 rpm or the allowable torque. If the actual flow rate and fluid supply pressure are effective and within their respective allowable ranges, the drill bit maintains the safe target flow rate and outputs a retraction prompt. If the operator does not stop the advance, the drilling load exceeds the current allowable drilling load, or the drill bit drive motor experiences overcurrent, the drill bit drive motor is stopped. This state can be maintained for a maximum of 10 to 120 seconds. If the drill bit's thermal state continues to decrease and cooling transfer is normal even after the maximum maintenance time is reached, the drill bit enters a cooling failure protection state.

[0105] In the cooling failure protection state, the drill bit drive motor is stopped, and the safe target flow rate is maintained, the fluid supply pump 210 is stopped, or the flow regulation component 230 is shut down, depending on the type of abnormality. If upstream water shortage, fluid supply line 220 rupture, serious leakage, waterless operation, or serious electrical fault is detected, the safe target flow rate is set to zero. This state can only be exited after the fault has been resolved and necessary manual verification and equipment calibration have been completed.

[0106] The recovery observation state includes a first recovery level and a second recovery level. The permissible drilling load for the first recovery level can be 30% to 50% of the normal drilling load, and for the second recovery level, it can be 60% to 80%, with each level held for 2 to 10 seconds. The next recovery level is initiated when the drill bit thermal condition and coolant transfer and heat exchange conditions both meet the corresponding recovery conditions. Normal drilling resumes once the second recovery level is completed and no temperature rebound occurs. If a temperature rebound or deterioration occurs at any recovery level, the system returns to the corresponding enhanced cooling state, limited drilling state, or feed stop cooling state.

[0107] The entry confirmation time, exit confirmation time, minimum holding time, maximum holding time, allowable drilling load, and recovery conditions for each state are calibrated based on the drill bit 110 specification, the drilled material 150, the response performance of the test piece, the response performance of the fluid supply system, and normal and abnormal tests, and saved according to the applicable configuration and parameter version.

[0108] Example 4 illustrates the switching of drill bit thermal state acquisition methods, data anomaly handling, and the implementation of the drill bit cooling control device.

[0109] like Figure 6As shown, the thermal state of the drill bit can be obtained through direct detection or indirect judgment. Direct detection determines the drill bit's thermal state based on the near-end temperature, the direction of temperature change, and the duration of the change. Indirect judgment determines the drill bit's thermal state and data reliability based on the coolant inlet temperature, outlet temperature, drilling load, drill bit 110 rotational speed, feed state, and drilling duration, referring to the calibration data table corresponding to the drill bit 110 specifications. The results of indirect judgment are not output as the actual temperature value of the drill bit 110's cutting end.

[0110] The calibration data sheet should include at least the drill bit 110 specification, drilled material 150 category, coolant inlet temperature range, effluent temperature range, drilling load range, drill bit 110 rotation speed range, propulsion status, drill bit thermal status category, data reliability status, and parameter version.

[0111] In one implementation, a stable state is output when the coolant inlet temperature, outlet temperature, drilling load, drill bit speed (110 rpm), and propulsion status all fall within their respective stable ranges; a state of slight heat accumulation or continuous heat accumulation is output when the outlet temperature continues to rise and the drilling load exceeds the stable range; and a rapid temperature rise state is output when the rate of change of the outlet temperature exceeds the rapid temperature rise boundary. When multiple conditions are simultaneously met, a state with a higher level of protection is output; if necessary inputs are invalid or do not match valid entries, the output data is unreliable. Each range and boundary is determined through calibration tests for the corresponding drill bit specifications.

[0112] If two to five consecutive new samples of the drill bit proximal temperature show over-range, abnormal jumps, or invalid flags, or if no new valid sample value is obtained for more than the sum of the temperature sampling period and the allowable communication delay, the direct detection method is confirmed to have failed. If the same valid sample value is reused in multiple control cycles, it is not directly considered a failure, but after the aforementioned time, it is marked as having no new data.

[0113] If the direct detection method fails, and the data required for indirect judgment and the calibration data table are valid, the system switches to the indirect judgment method and enters a restricted drilling state. The maximum degradation operation time for the indirect judgment method can be 1 to 10 seconds, determined based on the drill bit's 110 heat capacity, the detection component's response time, and safety tests under restricted drilling conditions. If a reliable drill bit thermal state cannot be established even after the maximum degradation operation time, the system enters a stop-feed cooling state and outputs a stop-advance prompt.

[0114] If the drill bit proximal temperature remains within the effective range for 3 to 10 consecutive valid new sampling values, shows continuous variation, and does not exhibit persistent inconsistencies with indirect judgment results, direct detection should be reinstated after recovery observation. Normal drilling should not commence until recovery confirmation is complete. If neither method can establish a reliable drill bit thermal state, the drill bit thermal state should be marked as unreliable. If the actual flow rate and fluid supply pressure can be confirmed, maintain the safe target flow rate and stop drilling; if neither can be confirmed, stop the drill bit drive motor and enter cooling failure protection mode.

[0115] like Figure 11 As shown, if one of the actual flow rate and the fluid supply pressure is invalid and the other is valid, the drilling state or the safe target flow rate is maintained based on the valid data, and the complete failure of the fluid supply is not directly determined; if neither the actual flow rate nor the fluid supply pressure can be confirmed, the cooling failure protection state is entered.

[0116] If the discharge fluid temperature sensor 320 fails, but the drill bit proximal temperature, actual flow rate, and supply fluid pressure are valid, the cooling response reference range will stop being updated, the safe target flow rate will be maintained, and drilling will be restricted. If the drill bit proximal temperature sensor 350 fails, but the data required for indirect judgment is valid, the system will switch to indirect judgment mode.

[0117] When the liquid arrival status is invalid, the discharged liquid temperature data is not used to establish a deterministic heat transfer status. Drilling is restricted, and the return fluid collection structure 400 is checked. When drilling upwards or when a continuous and stable return fluid cannot be formed, a sealed return fluid collection structure 400 or intermittent arrival detection can be used. The discharged liquid temperature is extracted only after the liquid arrival detection element 420 confirms that the discharged liquid has reached the effective sensing temperature zone. If an effective discharged liquid temperature cannot be obtained in multiple consecutive trial cycles, the establishment of the current cooling response reference range is stopped, a conservative factory range is adopted, and drilling is restricted.

[0118] If the drill bit proximal temperature sensor 350 is not installed and the discharged fluid cannot be stably collected, the drilling should be restricted based on the actual flow rate, supply pressure, and drilling load. The maximum duration of this restriction can be from 2 to 120 seconds. During this time, it is prohibited to increase the drill bit speed 110, allowable torque, and drilling load. If a reliable drill bit thermal state cannot be obtained even after the maximum duration has been reached, the feed should be stopped and the drill bit cooled down.

[0119] When communication between the sensor or controller is interrupted, increasing the drilling load should be immediately prohibited, and the current target flow rate should be maintained or switched to a safe target flow rate. If a single non-critical sensor recovers within 100 to 500 milliseconds, the corresponding data segment will be marked as communication disruption data and will not be used to update the cooling response reference range. When the communication interruption reaches the failure confirmation time, a stop-progress prompt or a stop-drill-drive motor will be output based on the current drill bit thermal state. Manual emergency stop, dry running without water, 220mm rupture in the fluid supply line, severe leakage, and severe electrical faults will directly trigger the protection output without waiting for two comprehensive analyses to complete the current control cycle.

[0120] The prompting output can be an indicator light, buzzer, vibrating element, or display. A decrease in thrust prompt corresponds to a limit level, while a stop in thrust prompt and a retraction prompt correspond to a protection level. If the operator fails to respond to the prompt and the drill bit's thermal condition continues to deteriorate, the lower-level state machine enters a higher-priority state.

[0121] The calibration tests include normal fluid supply, insufficient fluid supply, obstruction of the fluid supply channel 240, increased coolant inlet temperature, missing return fluid, restricted sampling channel, partial blockage of the drain outlet, abnormal test piece, gradual increase of thrust, sudden decrease of thrust, overload drilling, drill bit jamming at 110, stopping thrust for cooling, and manual retraction tests. Each calibration condition can be tested 3 to 5 times independently. If fewer than 3 valid tests are performed, conservative factory parameters are used; data corresponding to manual interruption, communication interruption, unplanned rebar cutting, or abnormal drill bit damage are marked as invalid.

[0122] Sampling records, comprehensive analysis results, state boundary parameter sets, control instructions, execution feedback, and exception records all include generation time, applicable objects, parameter values ​​or state values, effective status, exception reasons, and parameter versions. Control instructions also include the execution object, target value, validity period, and control priority. Execution feedback includes the actual executed value, execution status, and reasons for not achieving the target.

[0123] This embodiment also provides a drill bit cooling control device, including a processor, a memory, a data acquisition interface, and a control output interface. The data acquisition interface is connected to an inlet temperature detector 310, a discharge fluid temperature detector 320, a flow rate detector 330, a pressure detector 340, a drill bit proximal end temperature detector 350, a liquid arrival detector 420, and a drill bit operation detection interface. The control output interface is connected to a fluid supply pump 210, a flow regulation component 230, a drill bit drive motor, and a prompt output component. The memory stores the drill bit cooling control program, basic fluid supply parameters, calibration data, the current cooling response reference range, state boundary parameter groups, and operation records.

[0124] The above functions can be executed by the same processor, or they can be executed collaboratively by the main controller in the drilling equipment 100 and the coolant supply controller in the coolant supply device 200. When two controllers are used, the two controllers exchange timestamps, data validity status, status boundary parameters, and execution confirmation results using a unified time base; in the event of communication failure, the coolant supply controller performs safe coolant supply processing, and the main controller prohibits increasing the drilling load and outputs protection results.

[0125] The aforementioned processing steps are executed according to data dependencies. The comprehensive analysis of the drill bit's thermal state and the comprehensive analysis of the coolant transfer and heat exchange state are executed in parallel based on the same synchronous data window, and neither directly generates the final control command; the final target cooling control scheme is output by the underlying state machine based on the state boundary parameters formed by the two comprehensive analyses.

[0126] It should be noted that, for the sake of brevity, the foregoing method embodiments are described as a series of actions, but this does not mean that the application limits the order of the steps. Based on the ideas of this application, some steps can be executed in different orders or in parallel without affecting the functional implementation. Secondly, those skilled in the art should also understand that the specific embodiments described in the specification are preferred embodiments of the technical solutions of this application, and not limitations on the scope of protection of this application. All equivalent improvements or substitutions made within the spirit and principles of this application should be covered within the scope of protection of this application.

[0127] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A drill bit cooling control method based on cooling temperature data, characterized in that, The method is executed by an embedded controller connected to a handheld drilling device, including: Acquire coolant temperature data, coolant supply data, and drill bit operation data during the drilling process; When the drilling state is determined to be stable based on the drill bit operation data, the coolant supply is adjusted, and a target cooling control scheme matching the current drilling conditions is determined based on the coolant temperature data, coolant supply data and drill bit operation data before and after adjustment. Adjust the coolant supply according to the target cooling control scheme, and control the drill bit drive motor or output operation prompts to the operator.

2. The drill bit cooling control method based on cooling temperature data according to claim 1, characterized in that, The acquisition of coolant temperature data, coolant supply data, and drill bit operation data during the drilling process, and the determination of a stable drilling state based on the drill bit operation data, includes: The coolant temperature data includes the coolant inlet temperature and the coolant outlet temperature; The coolant supply data includes target flow rate, actual flow rate, supply pressure, and liquid arrival status; The drill bit operating data includes drill bit rotation speed and propulsion status, as well as one or more of drive motor current, spindle torque, axial propulsion force, propulsion speed and drill bit axial displacement. The drilling load is determined based on at least one of the drive motor current, the spindle torque and the axial propulsion force. The coolant temperature data, coolant supply data, and drill bit operation data are time-aligned according to the control cycle to form a synchronized data window; The most recent valid stable data window is determined from the synchronized data window before the current judgment time, and the valid stable data window is used as the reference window. The latest control cycle being judged is not included in the calculation of the reference value of the reference window. When the drill bit speed and drilling load are within the corresponding stable range, and the propulsion state is determined to remain stable based on the drill bit operation data, and this stability confirmation time is continuously reached, the drilling state is determined to be stable.

3. The drill bit cooling control method based on cooling temperature data according to claim 2, characterized in that, The adjustment of the coolant supply includes: The basic target flow rate is determined based on the drill bit specifications, the material being drilled, the drilling direction, the coolant inlet temperature, and the configuration of the fluid supply system. When the drilling is stable, the drill bit is not in a high-temperature dangerous state, the fluid supply pressure is lower than the safety upper limit, and the fluid supply actuator has an adjustment margin, the basic target flow rate is increased to the test target flow rate. The fluid supply actuator includes a fluid supply pump and a flow regulation component. During a single coolant supply adjustment process, only one of the coolant supply pump and the flow regulating component is changed. When the coolant supply pump is changed, the state of the flow regulating component remains unchanged. When the flow regulating component is changed, the output of the coolant supply pump remains stable. When the difference between the actual flow rate and the target flow rate is not greater than the larger of the repeatability error of the flow detection device and the minimum adjustment amount of the liquid supply actuator, and continues to reach the execution confirmation time, it is determined that the target flow rate has been executed. Maintain the target flow rate during the trial, and restore the target flow rate of the coolant to the base target flow rate after the trial holding time has been reached.

4. The drill bit cooling control method based on cooling temperature data according to claim 3, characterized in that, The step of determining a target cooling control scheme that matches the current drilling conditions based on the coolant temperature data before and after adjustment, the coolant supply data, and the drill bit operation data includes: Before the target flow rate of the coolant is increased, the temperature data of the discharged fluid is obtained during the period when the drilling status is stable and the target flow rate of the coolant does not change, forming a temperature stability window, and the original temperature change trend and normal fluctuation range are determined based on the temperature stability window. After the target flow rate of the coolant is increased, the actual flow rate response, supply pressure response, discharge fluid temperature response and drill bit thermal status response are obtained. The drill bit thermal status response includes the direction of change of thermal status category, response time and data reliability status determined based on the drill bit proximal temperature or indirect judgment results. The response time is calculated from the moment the target flow rate of the coolant is increased until the thermal status category changes and continues to reach the corresponding status and enters the confirmation time. The original temperature change trend is used to form the expected temperature range under the condition that the target flow rate of coolant is not increased. When the discharge temperature continues to deviate from the expected temperature range, and the deviation exceeds the sum of the normal fluctuation range and the repeated measurement error of the discharge temperature detection device and reaches the temperature response confirmation time, the discharge temperature response is determined to be generated. After the coolant target flow rate is restored, a recovery prediction range is formed based on the change trend of the discharge fluid temperature; when the discharge fluid temperature enters the recovery prediction range and continues to reach the temperature recovery confirmation time, temperature recovery is determined; when the discharge fluid temperature exceeds the recovery prediction range in the opposite direction to the temperature recovery direction after temperature recovery, temperature rebound is determined. Based on the actual flow response, the supply pressure response, the discharge fluid temperature response, the drill bit thermal state response, the temperature recovery, and the temperature rebound, a cooling response reference range for the current borehole is established, and the target cooling control scheme is determined based on the comparison results between the corresponding data during the current borehole process and the cooling response reference range. When the drilling stability condition fails, the target flow rate is not actually executed, the liquid arrival state is invalid, the temperature stability window is invalid, or a time synchronization anomaly occurs, the corresponding data will not be used to determine the target cooling control scheme.

5. The drill bit cooling control method based on cooling temperature data according to claim 4, characterized in that, The establishment of the current borehole cooling response reference range includes: Valid test records are stored according to the borehole depth range. The valid test records include the actual flow response time, the fluid supply pressure response time, the direction of the discharge fluid temperature response, the discharge fluid temperature response time, the temperature change amplitude, the temperature recovery time, the cooling holding time, the direction of the change of the drill bit thermal state category, the drill bit thermal state response time, and the data reliability status. The numerical response parameters include actual flow response time, supply pressure response time, discharge fluid temperature response time, temperature change amplitude, temperature recovery time, cooling hold time, and drill bit thermal state response time. The discharge fluid temperature response direction and the change direction of the drill bit thermal state category are used for directional consistency verification, and the data reliability status is used to determine whether the corresponding drill bit thermal state response participates in the establishment of the cooling response reference range. When there are three or four sets of valid test records for the same borehole depth range, the minimum to maximum effective values ​​of each numerical response parameter are used to form the corresponding numerical reference range; when there are five sets of valid test records, each numerical response parameter is sorted, and the second smallest to the second largest value after sorting is used to form the corresponding numerical reference range. When there are more than five valid test records, select the five most recent valid test records within the current borehole depth range and form a candidate reference range according to the processing method of the five valid test records; when the candidate reference range meets the single adjustment boundary and cumulative offset boundary, and the drill bit thermal state is stable, the coolant transfer and heat exchange state is normal, and the relevant data is reliable, it is updated to the current cooling response reference range; otherwise, the original cooling response reference range is retained. Upon entering an adjacent borehole depth range, the cooling response reference range of the previous borehole depth range is inherited as a temporary reference range, and a verification test is performed. If any numerical response parameter continuously exceeds the temporary reference range and allowable error and reaches the corresponding deviation confirmation condition, or if the change direction of the discharge fluid temperature response or the drill bit thermal state category is inconsistent with the direction reference corresponding to the temporary reference range, the cooling response reference range of the current borehole depth range is re-established. When the drill bit specifications, fluid supply channel specifications, coolant type, type of material being drilled, drilling direction, fluid supply system configuration, test piece configuration, and parameter version are all consistent with the historical records, the historical cooling response reference range will be used as a temporary reference range and converted into the current cooling response reference range after the verification test is passed. When the response parameters change gradually in the same direction, the cooling response reference range is updated within the single adjustment boundary and the cumulative offset boundary; when the response parameters cross the cooling response reference range and the allowable error, the cooling response reference range is frozen.

6. A drill bit cooling control method based on cooling temperature data according to claim 4 or 5, characterized in that, The step of determining the target cooling control scheme based on a comparison of relevant data from the current drilling process with the cooling response reference range includes: The drill bit thermal state comprehensive analysis and coolant transfer and heat exchange state comprehensive analysis are performed in parallel based on the same synchronous data window. The comprehensive analysis of the drill bit thermal state determines the drill bit thermal state based on the drill bit proximal temperature or indirect judgment results, drilling load, drill bit rotation speed, propulsion state and state duration, and forms a first state boundary parameter set; The comprehensive analysis of the coolant transfer and heat exchange state determines the coolant transfer and heat exchange state based on the target flow rate, actual flow rate, supply pressure, coolant inlet temperature, discharge temperature, liquid arrival state, target flow rate change time, and the cooling response reference range, and forms a second state boundary parameter set. The first state boundary parameter group and the second state boundary parameter group respectively include state category, data reliability state, allowable drilling load, state entry condition, state exit condition, state holding time, allowable transition state set, prohibition transition state set and recovery condition. The second state boundary parameter group also includes cooling response allowable time and fluid supply adjustment range. Neither the comprehensive analysis of the drill bit's thermal state nor the comprehensive analysis of the coolant transfer and heat exchange state reads the output of the other comprehensive analysis, and neither directly generates the final control commands for the fluid supply pump, flow regulation component, drill bit drive motor, or prompt output component.

7. The drill bit cooling control method based on cooling temperature data according to claim 6, characterized in that, The step of adjusting the coolant supply according to the target cooling control scheme and controlling the drill bit drive motor or outputting operation prompts to the operator includes: The state boundaries of the underlying state machine are determined based on the first state boundary parameter set and the second state boundary parameter set. The lower permissible drilling load in the two state boundary parameter sets is taken as the permissible drilling load of the bottom state machine, the allowable cooling response time in the second state boundary parameter set is taken as the allowable cooling response time of the bottom state machine, the longer confirmation time in the two state exit conditions is taken as the state exit confirmation time, the intersection of the two permissible transition state sets is taken as the permissible transition state set, and the union of the two prohibited transition state sets is taken as the prohibited transition state set. If no new valid state boundary parameter set is formed within the state boundary update cycle of any comprehensive analysis, the corresponding previous valid state boundary parameter set is used; when the duration of the failure to form a new valid state boundary parameter set reaches the failure confirmation time, the corresponding comprehensive analysis is determined to be continuously failed. If only one comprehensive analysis fails continuously, enter the restricted drilling state; if the current target flow rate is within the fluid supply adjustment range, and the actual flow rate and fluid supply pressure are both effective and within the corresponding allowable range, maintain the current target flow rate; otherwise, switch to the safe target flow rate and prohibit increasing the drilling load. If both comprehensive analyses continue to fail, the system will enter a stop-feed cooling state and output a stop-propulsion prompt; if the actual flow rate and fluid supply pressure cannot be confirmed, the drill bit drive motor will stop and the system will enter a cooling failure protection state. When there is no common state in the set of allowed transition states, the state that has met the entry conditions and has the highest priority is selected according to the priority order of cooling failure protection state, stop feed cooling state, restricted drilling state and enhanced cooling state; when none of the above states meet the entry conditions, the current state is maintained and increasing the drilling load is prohibited until a new set of effective state boundary parameters is formed.

8. The drill bit cooling control method based on cooling temperature data according to claim 7, characterized in that, The underlying state machine includes equipment verification state, reference range establishment state, normal drilling state, cooling response check state, enhanced cooling state, limited drilling state, feed stop cooling state, cooling failure protection state, and recovery observation state. Each state is mutually exclusive. Apart from the equipment calibration status, the priority of the cooling failure protection status, the feed stop cooling status, the drilling restriction status, the enhanced cooling status, the cooling response check status, the reference range establishment status, the recovery observation status, and the normal drilling status decreases in that order. When the drill bit is in a state of mild heat accumulation or the coolant transfer and heat exchange state is in a state of reduced effective heat exchange capacity, it enters the enhanced cooling state, increases the target flow rate of the coolant, and maintains the current drilling load or prevents the drilling load from increasing further. When the drill bit thermal state is characterized by continuous heat accumulation, the use of a temporary reference range, or the continuous failure of a single comprehensive analysis, it enters the restricted drilling state, maintains the current target flow rate or switches to a safe target flow rate, reduces the drill bit speed or allowable torque, and outputs a prompt to the operator to reduce the thrust. When the drill bit is in a rapid heating or high temperature danger state, both comprehensive analyses continue to fail, or the restricted drilling state reaches the maximum holding time but still fails to meet the exit conditions, the drill bit enters the stop feed cooling state, outputs a stop propulsion prompt, and reduces the drill bit speed or allowable torque. When the feed is stopped and the liquid supply pressure is in the cooling state, the actual flow rate and the liquid supply pressure are both effective and within the corresponding allowable range, the safe target flow rate is maintained and a retraction prompt is output. If the operator fails to stop the drilling, the drilling load exceeds the current allowable drilling load, or the drill bit drive motor experiences an overcurrent, the drill bit drive motor shall be stopped. When the stop-feed cooling state reaches the maximum holding time and the exit condition is not met, or when the actual flow rate and liquid supply pressure cannot be confirmed, the cooling failure protection state is entered. The recovery observation state includes a first recovery level and a second recovery level. When the corresponding recovery conditions are met and the corresponding holding time is reached in both the drill bit thermal state and the coolant transfer and heat exchange state, the allowable drilling load is gradually increased. When the second recovery level is completed and no temperature rebound occurs, the normal drilling state is entered.

9. The drill bit cooling control method based on cooling temperature data according to claim 8, characterized in that, The thermal state of the drill bit is obtained through direct detection or indirect judgment. The direct detection method determines the thermal state of the drill bit based on the near-end temperature of the drill bit, the direction of temperature change, and the duration of the change. The indirect judgment method determines the thermal state and data reliability of the drill bit based on the coolant inlet temperature, outlet temperature, drilling load, drill bit speed, propulsion status and drilling duration in a calibration data table corresponding to the drill bit specifications. If the near-end temperature of the drill bit continuously shows an over-range, abnormal jump, or invalid flag and reaches the direct detection failure confirmation time, or if no new valid sample value is obtained for more than the sum of the temperature sampling period and the allowable communication delay, the direct detection method is determined to be faulty. When the direct detection method fails, and the data required by the indirect judgment method and the calibration data table are valid, switch to the indirect judgment method and enter the restricted drilling state; When the drill bit proximal temperature remains effective and changes continuously, and there is no continuous inconsistency with the results of the indirect judgment method, and the direct detection recovery confirmation time has been reached, the direct detection method is re-adopted after recovery observation. If neither the direct detection method nor the indirect judgment method can establish a reliable drill bit thermal state, a stop-propulsion prompt will be output; if both the actual flow rate and the fluid supply pressure are invalid, the drill bit drive motor will be stopped and the cooling failure protection will be activated.

10. A drill bit cooling control device, characterized in that, Includes processor, memory, data acquisition interface, and control output interface; The data acquisition interface is used to connect to the coolant temperature detection device, flow detection device, pressure detection device, liquid arrival detection device, and drill bit operation detection interface; The control output interface is used to connect to the liquid supply pump, flow regulation component, drill bit drive motor and prompt output component; The memory stores a drill bit cooling control program, which, when executed by the processor, causes the drill bit cooling control device to perform the method according to any one of claims 1 to 9.

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