Gun drill broken tool detection system and method based on Bernoulli equation and mean value algorithm

Abstract

The invention relates to the technical field of small-diameter gun drill broken tool detection, in particular to a gun drill broken tool detection system and method based on a Bernoulli equation and a mean value algorithm. The gun drill broken tool detection system comprises a small-diameter single-blade gun drill, an extension rod, a hollow main shaft, a rotating joint, a sensor mounting base, a pressure transmitter and an upper computer. The pressure signals are converted into digital signals through the A / D conversion module, real-time pressure values are obtained, the pressure values are collected in each drilling period, the average value is calculated, and whether tool breakage occurs or not is judged by comparing the average pressure fluctuation value of two adjacent holes with a preset threshold interval, so that whether the small-diameter single-blade gun drill is broken or not is detected. According to the technical scheme, the influence of oil temperature changes on long-term pressure monitoring is avoided, high-sensitivity detection can be achieved only through a common pressure transmitter, and the problem that due to the characteristics of small feeding resistance, hidden machining and the like of a small-diameter gun drill, traditional detection means such as a current method and a visual method fail is solved.

Description

Technical Field

[0001] This invention relates to the field of small-diameter gun drill tool breakage detection technology, and in particular to a gun drill tool breakage detection system and method based on Bernoulli's equation and mean value algorithm. Background Technology

[0002] The ring die used for shrimp feed production requires the machining of up to 45,000 to 70,000 1.2mm or 1.0mm die holes with a depth of 23 to 30mm. Due to the large machining volume and the high surface roughness requirements, currently only small-diameter single-edged gun drills can be used for machining. If a tool breaks during the automatic machining process and is not detected in time, it will greatly extend the machining time and seriously affect the machining progress. Therefore, it is necessary to use a tool monitoring method to detect whether the small-diameter single-edged gun drill breaks during the machining process.

[0003] Existing tool monitoring methods include visual methods, current / torque methods, and sound signal methods. When using visual methods, small-diameter single-edged gun drills are completely enclosed inside the guide assembly and the machined hole, making them impossible to capture by the camera. Furthermore, high-pressure cooling oil circulates inside the small-diameter single-edged gun drill during machining, so oil mist from the machine tool also affects the camera. When using current / torque methods, the feed rate of a small-diameter single-edged gun drill is only 0.005 mm / r, and the axial feed resistance is negligible during drill wear or breakage, making it impossible to detect the jumps in current or torque of the driving components caused by drill breakage. However, when using sound signal methods, the subtle changes in small-diameter single-edged gun drills during wear and breakage cannot be detected against the background of machine tool noise. Moreover, due to the small diameter and slender, brittle nature of the tool, the hidden machining process renders probe methods and vibration detection methods ineffective.

[0004] Meanwhile, during the machining process of a small-diameter single-edged gun drill, high-pressure cooling oil is introduced into the center of the tool. This high-pressure cooling oil is released through an oil pump and pressurization circuit, ultimately exiting through an oil hole at the drill tip, forming an open-circuit center-outlet cooling system. According to Bernoulli's equation, the process pressure in this center-outlet system is affected by the cutting fluid density, nozzle diameter, and flow coefficient. When a small-diameter gun drill breaks, the specific location and cross-sectional shape are random. The shape and distribution of the oil nozzles change during and after the breakage, and the edge roughness also changes. This will affect the flow coefficient C. dChanges in the value cause changes in the system pressure. Theoretically, by capturing these pressure changes and converting them into data, and by separating the characteristic differences in the converted data, it can be determined whether the tool has broken. However, traditional tool monitoring algorithms monitor dynamic data online and compare the real-time data with a given comparison value. But the machining time for small-diameter ring dies can be as long as 6 to 12 days. During this process, changes in oil temperature affect changes in the density of the cooling oil, and changes in density also lead to changes in pressure. Using this traditional algorithm greatly increases the probability of false alarms, making it impractical.

[0005] In summary, existing tool monitoring methods are insufficient to detect whether a small-diameter single-edged gun drill breaks during machining. Summary of the Invention

[0006] The purpose of this invention is to provide a gun drill breakage detection system and method based on Bernoulli's equation and mean value algorithm, which solves the problem that existing tool monitoring methods are difficult to detect whether small-diameter single-edged gun drills break during machining.

[0007] To achieve the above objectives, the present invention provides a gun drill breakage detection system based on Bernoulli's equation and mean value algorithm. The gun drill breakage detection system includes a small-diameter single-edged gun drill, an extension rod, a hollow spindle, a rotary joint, a sensor mounting base, a pressure transmitter, and a host computer. The small-diameter single-edged gun drill is fixed to the extension rod by a chuck. The extension rod is inserted into and fixed in the hollow spindle. The tail end of the hollow spindle is connected to the rotary joint. The end of the rotary joint away from the hollow spindle is connected to the sensor mounting base through a high-pressure hose. The pressure transmitter is installed on the sensor mounting base. The end of the sensor mounting base away from the high-pressure hose is connected to the machine tool oil circuit.

[0008] The host computer is equipped with an A / D conversion module, a data sampling module, a mean calculation module, a fluctuation value calculation module, a threshold setting module, and a judgment module. The output terminal of the pressure transmitter is connected to the A / D conversion module. The pressure transmitter is used to convert the oil pressure signal of the oil circuit into an analog current signal. The A / D conversion module is used to convert the analog current signal into a digital signal to obtain the real-time pressure value. The data sampling module is used to continuously sample and store the currently acquired real-time pressure value into the data register of the host computer at preset fixed intervals after each drilling step begins. Furthermore, it is used to record the real-time pressure value at the end of the current drilling step. When the data sampling stops, the sampling count is recorded. The mean calculation module is used to calculate the average pressure value for each drilling step. The fluctuation value calculation module obtains the average oil pressure fluctuation value between two adjacent drilling steps based on the average pressure value obtained by the mean calculation module. The threshold setting module is used to set the upper limit value and the lower limit value of the average oil pressure fluctuation between two adjacent drilling steps. The judgment module is used to compare the calculated average oil pressure fluctuation value with the set upper limit value and lower limit value of the average oil pressure fluctuation to determine whether the tool has broken.

[0009] The formula used in the mean calculation module to calculate the average pressure during each drilling step is as follows:

[0010] Avg m ;

[0011] In the formula, Avg m P represents the average pressure during the m-th drilling step, where n is the number of samples taken during the current drilling step. i This represents the pressure value sampled for the i-th time during the current drilling step.

[0012] The fluctuation value calculation module uses the average pressure Avg1 during the first drilling step as the basic self-learning data. The specific calculation formula for the average oil pressure fluctuation value ΔP during each drilling step is as follows:

[0013] When drilling the second hole: ΔP1 = Avg2 - Avg1;

[0014] When drilling the 3rd hole: △P2=Avg3-Avg2;

[0015] When drilling the 4th hole: △P3=Avg4-Avg3;

[0016] When drilling the m-th hole: △P m =Avg m -Avg m-1 .

[0017] The upper limit of the average oil pressure fluctuation between two adjacent drilling steps in the threshold setting module is denoted as ΔP. max The upper limit of the average oil pressure fluctuation between two adjacent drilling steps is ΔP. min .

[0018] In the determination module, △P m respectively with △P max and △P min Compare, if △P m Not in △P max and △P min If the range is between 0 and 1, then the tool is determined to be broken.

[0019] This invention also provides a method for detecting broken gun drill tools based on Bernoulli's equation and the mean algorithm, applied to the gun drill tool breakage detection system described above, comprising the following steps:

[0020] The threshold setting module is used to set the upper limit value of the average oil pressure fluctuation between two adjacent drilling steps and the lower limit value of the average oil pressure fluctuation between two adjacent drilling steps;

[0021] The pressure transmitter is used to convert the oil pressure signal of the oil circuit into an analog current signal in real time, and the analog current signal is converted into a digital signal through an A / D conversion module to obtain the real-time pressure value;

[0022] The data sampling module is used to acquire real-time pressure values ​​at preset fixed intervals during each drilling process, until the current drilling process ends, along with the pressure value data and the number of samplings.

[0023] Based on the data collected by the data sampling module, the average pressure during each drilling process is calculated using the mean calculation module.

[0024] Based on the average pressure value obtained by the mean calculation module for each drilling process, the average oil pressure fluctuation value of two adjacent drilling steps is obtained by the fluctuation value calculation module.

[0025] The determination module compares the calculated average oil pressure fluctuation value with the set upper and lower limits of the average oil pressure fluctuation. If the average oil pressure fluctuation value is not within the range of the upper and lower limits of the average oil pressure fluctuation, the tool is determined to be broken.

[0026] This invention discloses a gun drill tool breakage detection system and method based on Bernoulli's equation and mean value algorithm, comprising a small-diameter single-edged gun drill, an extension rod, a hollow spindle, a rotary joint, a sensor mounting base, a pressure transmitter, and a host computer. This technical solution utilizes the principle of Bernoulli's equation to determine the flow coefficient C of the internal oil passage when the tool breaks.d The phenomenon of sudden changes leading to significant oil pressure fluctuations is addressed by using the pressure transmitter to acquire oil pressure signals in real time. These signals are then converted into digital signals by the A / D conversion module to obtain real-time pressure values. The average value calculation module and the fluctuation value calculation module work together to acquire pressure values ​​and calculate average values ​​within each drilling cycle. By comparing the average pressure fluctuation values ​​of two adjacent holes with a preset threshold range set by the threshold setting module, it is determined whether a tool breakage has occurred. This method detects whether the small-diameter single-edged gun drill has broken. This technical solution avoids the impact of oil temperature changes on long-term pressure monitoring and only requires a common pressure transmitter to achieve high-sensitivity detection. It solves the problem that traditional detection methods such as current methods and visual methods fail due to the low feed resistance and concealed machining characteristics of small-diameter gun drills. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the principle of the gun drill broken tool detection system based on Bernoulli's equation and mean value algorithm provided by the present invention.

[0029] Figure 2 This is a schematic diagram of the operating principle of the gun drill broken tool detection system based on Bernoulli's equation and mean value algorithm provided by the present invention.

[0030] Figure 3 This is a sampling diagram of the data sampling module provided by the present invention.

[0031] Figure 4 This is a schematic diagram of the determination module provided by the present invention.

[0032] Figure 5 This is a flowchart of the steps of the gun drill tool breakage detection method based on Bernoulli's equation and mean value algorithm provided by the present invention.

[0033] Figure 6 This is a schematic diagram illustrating the actual judgment of a 1.2 mm ring die machining process using a gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm, as provided in the application example of this invention.

[0034] Figure 7 This is a schematic diagram illustrating the actual judgment of a 1.0 mm ring die machining process using a gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm, as provided in the application example of this invention.

[0035] 101-Small-diameter single-edged gun drill, 102-Extension rod, 103-Hollow spindle, 104-Rotary joint, 105-Sensor mounting base, 106-Pressure transmitter, 107-Host computer, 108-Chuck, 109-High-pressure hose, 110-Machine tool oil circuit, 111-A / D conversion module, 112-Data sampling module, 113-Average calculation module, 114-Fluctuation value calculation module, 115-Threshold setting module, 116-Judgment module. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] Please see Figures 1 to 4 This invention provides a gun drill breakage detection system based on Bernoulli's equation and mean value algorithm. The gun drill breakage detection system includes a small-diameter single-edged gun drill 101, an extension rod 102, a hollow spindle 103, a rotary joint 104, a sensor mounting base 105, a pressure transmitter 106, and a host computer 107. The small-diameter single-edged gun drill 101 is fixed to the extension rod 102 by a chuck 108. The extension rod 102 is inserted into the hollow spindle 103 and fixed. The tail end of the hollow spindle 103 is connected to the rotary joint 104. The end of the rotary joint 104 away from the hollow spindle 103 is connected to the sensor mounting base 105 through a high-pressure hose 109. The pressure transmitter 106 is installed on the sensor mounting base 105. The end of the sensor mounting base 105 away from the high-pressure hose 109 is connected to the machine tool oil circuit 110.

[0038] The host computer 107 is equipped with an A / D conversion module 111, a data sampling module 112, a mean calculation module 113, a fluctuation value calculation module 114, a threshold setting module 115, and a judgment module 116. The output terminal of the pressure transmitter 106 is connected to the A / D conversion module 111. The pressure transmitter 106 is used to convert the oil pressure signal of the oil circuit into a 4~20mA current analog signal. The A / D conversion module 111 is used to convert the current analog signal into a digital signal to obtain the real-time pressure value. The data sampling module 112 is used to continuously sample and store the currently collected real-time pressure value in the data storage of the host computer 107 at preset fixed intervals after each drilling step begins. The register is used to calculate the average pressure value for each drilling step. The average value calculation module 113 calculates the average pressure value for each drilling step. The fluctuation value calculation module 114 obtains the average oil pressure fluctuation value for two adjacent drilling steps based on the average pressure value obtained by the average value calculation module 113 for each drilling step. The threshold setting module 115 sets the upper limit value and the lower limit value of the average oil pressure fluctuation for two adjacent drilling steps. The judgment module 116 compares the calculated average oil pressure fluctuation value with the set upper limit value and lower limit value of the average oil pressure fluctuation to determine whether the tool has broken.

[0039] In this embodiment, the technical solution utilizes Bernoulli's equation principle, where the flow coefficient C of the internal oil passage changes when the tool breaks. d The phenomenon of sudden changes leading to significant oil pressure fluctuations is addressed by using the pressure transmitter 106 to acquire oil pressure signals in real time. These signals are then converted into digital signals by the A / D conversion module 111 to obtain real-time pressure values. The average value calculation module 113 and the fluctuation value calculation module 114 work together to acquire pressure values ​​and calculate average values ​​within each drilling cycle. By comparing the average pressure fluctuation values ​​of two adjacent holes with the threshold range preset by the threshold setting module 115, it is determined whether a tool breakage has occurred. This allows for the detection of whether the small-diameter single-edged gun drill 101 has broken. This technical solution avoids the impact of oil temperature changes on long-term pressure monitoring, and only requires a common pressure transmitter 106 to achieve high-sensitivity detection. It solves the problem that traditional detection methods such as current methods and visual methods fail due to the low feed resistance and concealed machining characteristics of small-diameter gun drills.

[0040] The specific formula for calculating the pressure of the central water outlet system formed during the machining process of a small-diameter single-edged gun drill, derived from Bernoulli's equation, is as follows:

[0041]

[0042] In the formula, For pressure, The density of the cutting fluid. C represents the cutting fluid flow rate. d d is the flow coefficient (dimensionless), and d is the nozzle diameter (tool outlet diameter).

[0043] Specifically, when machining a ring die, the first step is to obtain the required process pressure P by adjusting the flow rate Q. Once the pressure is established, the formula shows that three variables affect the pressure change: cutting fluid density, etc. Nozzle diameter d and flow coefficient C d Cutting fluid density While it appears to be a fixed value, it actually varies depending on the temperature of the cooling oil. Once the tool is determined, its nozzle diameter d is also determined. C d This is the most critical and uncertain parameter in the formula. It reflects the actual energy loss (friction, runoff, extrusion) of the cutting oil flowing through the drill bit. Its value is not constant; it is related to the shape, chamfer, roughness, and length-to-diameter ratio of the nozzle orifice. The oil injection orifice of a small-diameter gun drill is not a round hole but a kidney-shaped elongated hole. This hole is not planar but distributed on several intersecting angular planes. When a small-diameter gun drill breaks, the specific location and cross-sectional shape are random. During and after the fracture, the shape and distribution of the oil injection orifice change, and the edge roughness also changes. This will affect the flow coefficient C. d Changes in the pressure value cause changes in the system pressure value. By capturing these pressure changes and converting them into data, and by separating the characteristic differences in the converted data, it can be determined whether the tool has broken.

[0044] Furthermore, such as Figure 3 As shown, the specific operation of the data sampling module 112 is as follows:

[0045] When the m-th drilling step begins, the current pressure P value is continuously sampled and stored in the data register (P1, P2, P3, P4...Pn) every fixed period T (e.g., 500 milliseconds). Data sampling stops when the current drilling ends and the number of samplings n is counted.

[0046] Furthermore, the formula used in the mean calculation module 113 to calculate the average pressure during each drilling step is as follows:

[0047] Avg m ;

[0048] In the formula, Avg m P represents the average pressure during the m-th drilling step, where n is the number of samples taken during the current drilling step. i This represents the pressure value sampled for the i-th time during the current drilling step.

[0049] Furthermore, the fluctuation value calculation module 114 uses the average pressure Avg1 during the first drilling step as the basic self-learning data. The specific calculation formula for the average oil pressure fluctuation value ΔP during each drilling step by the fluctuation value calculation module 114 is as follows:

[0050] When drilling the second hole: ΔP1 = Avg2 - Avg1;

[0051] When drilling the 3rd hole: △P2=Avg3-Avg2;

[0052] When drilling the 4th hole: △P3=Avg4-Avg3;

[0053] When drilling the m-th hole: △P m =Avg m -Avg m-1 .

[0054] Specifically, during drilling the first hole: the average pressure Avg1 during the first drilling step is used as the basic self-learning data, therefore the first hole is not detected.

[0055] In this embodiment, the average pressure Avg1 during the first drilling step is stored in the system as basic self-learning data. It should be noted that if the drill bit breaks during the drilling of this hole, it will not be detected because self-learning data has not yet been established, but the probability of this is negligible.

[0056] Since the flow coefficient C is not broken d The value is constant, and the period between each pair of holes is ≤2 minutes. The change in oil temperature is approximately constant within such a short period, so the average oil pressure fluctuation value ΔP between adjacent holes should also be constant.

[0057] Furthermore, the upper limit of the average oil pressure fluctuation between two adjacent drilling steps in the threshold setting module 115 is calculated as ΔP. max The upper limit of the average oil pressure fluctuation between two adjacent drilling steps is ΔP. min .

[0058] like Figure 4 As shown, the determination module 116 will determine △P m respectively with △P max and △P min Compare, if △P m Not in △P max and △P min If the range is between 0 and 1, then the tool is determined to be broken.

[0059] In this embodiment, oil pressure data is sampled during drilling, and the average pressure Avg at the end of each drilling step is recorded.m The calculation of the oil pressure fluctuation value ΔP and the interval comparison judgment are performed by the PLC or industrial control computer, with the upper limit value ΔP. max and lower limit value △P min A value is determined by processing test data and input into the human-machine interface (HMI). If the drill bit breaks, the PLC or industrial control computer sends a signal to the CNC system, or the PLC directly pauses the current processing and gives an alarm prompt.

[0060] Please see Figure 5 The present invention also provides a method for detecting broken gun drill tools based on Bernoulli's equation and mean value algorithm, applied to the gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm as described above, including the following steps:

[0061] S1: The threshold setting module 115 is used to set the upper limit value of the average oil pressure fluctuation of two adjacent drilling steps and the lower limit value of the average oil pressure fluctuation of two adjacent drilling steps.

[0062] S2: The pressure transmitter 106 is used to convert the oil pressure signal of the oil circuit into an analog current signal in real time, and the analog current signal is converted into a digital signal through the A / D conversion module 111 to obtain the real-time pressure value.

[0063] S3: The data sampling module 112 is used to acquire the real-time pressure value data and sampling number at each preset fixed period during each drilling process until the current drilling process ends.

[0064] S4: Based on the data collected by the data sampling module 112, the average pressure during each drilling process is calculated using the mean calculation module 113;

[0065] S5: Based on the average pressure value obtained by the mean value calculation module 113 in each drilling process, the average oil pressure fluctuation value of two adjacent drilling steps is obtained by the fluctuation value calculation module 114.

[0066] S6: The determination module 116 compares the calculated average oil pressure fluctuation value with the set upper and lower limits of the average oil pressure fluctuation. If the average oil pressure fluctuation value is not within the range of the upper and lower limits of the average oil pressure fluctuation, the tool is determined to be broken.

[0067] In this embodiment, the technical solution utilizes the Bernoulli equation principle. When the tool breaks, the flow coefficient of its internal oil circuit changes abruptly, leading to a significant change in oil pressure. The pressure transmitter 106 collects the oil pressure signal in real time, which is converted into a digital signal by the A / D conversion module 111 to obtain the real-time pressure value. The average value calculation module 113 and the fluctuation value calculation module 114 work together to collect the pressure value and calculate the average value in each drilling cycle. By comparing the average pressure fluctuation value of two adjacent holes with the threshold range preset by the threshold setting module 115, it is determined whether the tool breakage has occurred, thereby realizing the detection of whether the small-diameter single-edged gun drill 101 has broken. This technical solution avoids the influence of oil temperature changes on long-term pressure monitoring. Only an ordinary pressure transmitter 106 is needed to achieve high-sensitivity detection, solving the problem that traditional detection methods such as current method and visual method fail due to the characteristics of small-diameter gun drills such as low feed resistance and concealed machining.

[0068] Application example:

[0069] Using the gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm provided in this technical solution, tool breakage monitoring trial machining of 1.2 mm and 1.0 mm ring dies was performed on two machine tools respectively.

[0070] Among them, such as Figure 6 As shown, in the experimental data of 1.2 mm ring die machining: the four spindles continuously machined a total of 62,000 holes, with each spindle machining 15,500 holes. A total of one spindle with a broken drill bit was successfully detected by the system and the system determined that the hole was broken.

[0071] Based on historical average oil pressure fluctuations, it can be seen that when drilling is not interrupted, the ΔP value is ≤0.15MPa, indicating stable data.

[0072] Based on historical average oil pressure fluctuation data, ΔP is initially determined. max The upper limit is 0.25 MPa, and the lower limit is ΔP. min The value is -0.25 MPa. (The range should be appropriately widened to reduce false alarms.)

[0073] When the drill bit failure alarm occurs, the average oil pressure fluctuation value ΔP = -0.45MPa. This value is much larger than the value when the drill bit has not failed, exhibiting a distinct characteristic. The system captures this characteristic information through interval comparison.

[0074] Among them, such as Figure 7 As shown in the experimental data of 1.0 mm ring die machining: a total of 70,384 holes were machined continuously by 4 spindles, with 17,596 holes machined by each spindle. A total of 1 spindle with a broken drill bit was successfully detected by the system and the system determined that the hole was broken.

[0075] Based on historical average oil pressure fluctuations, it can be seen that when drilling is not interrupted, the ΔP value is ≤0.16MPa, indicating stable data.

[0076] Based on historical average oil pressure fluctuation data, ΔP is initially determined. max The upper limit is 0.25 MPa, and the lower limit is ΔP. min The value is -0.25 MPa. (The range should be appropriately widened to reduce false alarms.)

[0077] When the drill bit breaks, the average oil pressure fluctuation value ΔP = -0.37MPa. This value is much larger than the value when the drill bit does not break, which is a distinct feature. The system captures this feature information through interval comparison.

[0078] Furthermore, the gun drill bit breakage detection system based on Bernoulli's equation and mean value algorithm provided in this technical solution is used to monitor the processing of drill bits of different diameters, and the data is listed below:

[0079] Cutting tool diameter (mm) Average oil pressure fluctuation value (MPa) when drilling is not interrupted Average oil pressure fluctuation during drilling failure (MPa) 1.0 -0.15~0.15 -0.35~-0.5 1.2 -0.15~0.15 -0.35~-0.5 1.6 -0.15~0.15 -0.45~-0.6 2.0 -0.15~0.15 -0.5~-0.75

[0080] The conclusions show that the data validates the applicability of Bernoulli's equation, and the flow coefficient C is valid when the drill string is not interrupted. d Because the flow rate is stable, the average oil pressure fluctuation value ΔP is also stable. After the tool breaks, the average oil pressure fluctuation value ΔP increases significantly, indicating that the flow coefficient C increases after the drill breaks. d The situation has changed. Current test data shows that the flow coefficient C after drill bit breakage... d The pressure tends to increase, and the average pressure Avg m As the value decreases, the pressure fluctuation value ΔP becomes negative. Furthermore, as the tool diameter increases, the data characteristics of drill breakage become more pronounced and easier for the system to detect.

[0081] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm, characterized in that, The system includes a small-diameter single-edged gun drill, an extension rod, a hollow spindle, a rotary joint, a sensor mounting base, a pressure transmitter, and a host computer. The small-diameter single-edged gun drill is fixed to the extension rod by a chuck. The extension rod is inserted into and fixed in the hollow spindle. The tail end of the hollow spindle is connected to the rotary joint. The end of the rotary joint away from the hollow spindle is connected to the sensor mounting base via a high-pressure hose. The pressure transmitter is mounted on the sensor mounting base. The end of the sensor mounting base away from the high-pressure hose is connected to the machine tool oil circuit. The host computer is equipped with an A / D conversion module, a data sampling module, a mean calculation module, a fluctuation value calculation module, a threshold setting module, and a judgment module. The output terminal of the pressure transmitter is connected to the A / D conversion module. The pressure transmitter is used to convert the oil pressure signal of the oil circuit into an analog current signal. The A / D conversion module is used to convert the analog current signal into a digital signal to obtain the real-time pressure value. The data sampling module is used to continuously sample and store the currently acquired real-time pressure value into the data register of the host computer at preset fixed intervals after each drilling step begins. Furthermore, it is used to record the real-time pressure value at the end of the current drilling step. When the data sampling stops, the sampling count is recorded. The mean calculation module is used to calculate the average pressure value for each drilling step. The fluctuation value calculation module obtains the average oil pressure fluctuation value between two adjacent drilling steps based on the average pressure value obtained by the mean calculation module. The threshold setting module is used to set the upper limit value and the lower limit value of the average oil pressure fluctuation between two adjacent drilling steps. The judgment module is used to compare the calculated average oil pressure fluctuation value with the set upper limit value and lower limit value of the average oil pressure fluctuation to determine whether the tool has broken.

2. The gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm as described in claim 1, characterized in that, The formula used in the mean calculation module to calculate the average pressure during each drilling step is as follows: Avg m ; In the formula, Avg m P represents the average pressure during the m-th drilling step, where n is the number of samples taken during the current drilling step. i This represents the pressure value sampled for the i-th time during the current drilling step.

3. The gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm as described in claim 2, characterized in that, The fluctuation value calculation module uses the average pressure Avg1 during the first drilling step as the basic self-learning data. The specific calculation formula for the average oil pressure fluctuation value ΔP during each drilling step is as follows: When drilling the second hole: ΔP1 = Avg2 - Avg1; When drilling the 3rd hole: △P2=Avg3-Avg2; When drilling the 4th hole: △P3=Avg4-Avg3; When drilling the m-th hole: △P m =Avg m -Avg m-1 .

4. The gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm as described in claim 3, characterized in that, The upper limit value of the average oil pressure fluctuation between two adjacent drilling steps in the threshold setting module is ΔP. max The upper limit of the average oil pressure fluctuation between two adjacent drilling steps is ΔP. min .

5. The gun drill tool breakage detection system based on Bernoulli's equation and mean value algorithm as described in claim 4, characterized in that, The determination module will include △P m respectively with △P max and △P min Compare, if △P m Not in △P max and △P min If the range is between 0 and 1, then the tool is determined to be broken.

6. A method for detecting broken gun drill tools based on Bernoulli's equation and mean-value algorithm, applied to the gun drill tool breakage detection system based on Bernoulli's equation and mean-value algorithm as described in claim 1, characterized in that, Includes the following steps: The threshold setting module is used to set the upper limit value of the average oil pressure fluctuation between two adjacent drilling steps and the lower limit value of the average oil pressure fluctuation between two adjacent drilling steps; The pressure transmitter is used to convert the oil pressure signal of the oil circuit into an analog current signal in real time, and the analog current signal is converted into a digital signal through an A / D conversion module to obtain the real-time pressure value; The data sampling module is used to acquire real-time pressure values ​​at preset fixed intervals during each drilling process, until the current drilling process ends, along with the pressure value data and the number of samplings. Based on the data collected by the data sampling module, the average pressure during each drilling process is calculated using the mean calculation module. Based on the average pressure value obtained by the mean calculation module for each drilling process, the average oil pressure fluctuation value of two adjacent drilling steps is obtained by the fluctuation value calculation module. The determination module compares the calculated average oil pressure fluctuation value with the set upper and lower limits of the average oil pressure fluctuation. If the average oil pressure fluctuation value is not within the range of the upper and lower limits of the average oil pressure fluctuation, the tool is determined to be broken.

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