Tool calibration method and device

Abstract

The present application relates to the field of tool calibration, and provides a tool calibration method and device. The tool calibration method calibrates the tool installed in the machining tool holder by using the tool calibration device, and comprises the following steps: obtaining machining instructions, triggering automatic calibration instructions integrated with tool calling instructions, controlling the measuring head arranged at the end of the measuring arm to collect key size parameters of the tool in the machining tool holder, comparing the corrected key size parameters with the pre-stored normal size parameter database of the corresponding tool model, and determining the tool state according to the comparison of the absolute deviation and the preset deviation threshold. The tool calibration method can accurately identify the size deviation caused by iron filings and foreign matters, prevent unqualified tools from flowing into the machining link, solve the machining quality fluctuation problem caused by the lack of pre-calibration in the prior art, and meet the size calibration requirements of high-precision numerical control machining.

Description

Technical Field

[0001] This invention relates to the field of tool calibration, and provides a tool calibration method and apparatus. Background Technology

[0002] The statements herein are provided only as background information in connection with this application and do not necessarily constitute prior art.

[0003] In existing tool measurement technologies, tool measuring devices are typically fixed and cannot be flexibly stored. This often leads to interference between the device and the machine tool's machining parts or tool magazine in the machine tool environment, thus limiting the effective use of space. Secondly, some tool oscillation devices rely on simple motors or rotary devices for drive, resulting in low positioning accuracy, with errors generally greater than 0.5 ohms. This makes it difficult to meet the stringent requirements of high-precision machining scenarios.

[0004] The existing tool calibration process is also very cumbersome and inflexible. Traditional methods require external calibration equipment for calibration, and a single calibration usually takes more than 15 minutes. Summary of the Invention

[0005] This invention provides a tool calibration method to address the shortcomings of related technologies where tool calibration is difficult to meet the production requirements of high-precision CNC machining.

[0006] This invention also provides a tool calibration device.

[0007] A first aspect of the present invention provides a tool calibration method, which uses a tool calibration device to calibrate a tool installed in a machining tool holder. The method includes the following steps: S1: Obtain the machining instruction, execute the tool calling process according to the machining instruction, and retrieve the tool to be processed from the tool magazine to the machining tool holder and clamp it; S2: Triggers an automatic calibration command integrated with the tool recall command, controlling the swing component to drive the measuring arm to swing from the stationary position to the measuring position; S3: Control the probe set at the end of the measuring arm to collect key dimension parameters of the tool in the machining tool holder, and simultaneously collect environmental data through the environmental compensation module to correct the key dimension parameters in real time; S4: Compare the corrected critical dimension parameters with the pre-stored database of normal dimension parameters for the corresponding tool model for absolute deviation; S5: If the absolute deviation is within the preset deviation threshold, the tool condition is deemed qualified and the machining process begins; if the absolute deviation exceeds the preset deviation threshold, it is determined that there are foreign objects such as iron filings adhering to the contact surface between the tool and the machining tool holder, an alarm signal is issued and machining is suspended.

[0008] According to an embodiment of the present invention, in step S3, the environmental compensation module corrects the displacement data collected by the probe using a polynomial fitting algorithm, and the calculation formula for the compensation amount ΔL is: ΔL=a×ΔT+b×A+c+d×ΔT×A; Where ΔT is the difference between the actual temperature and the standard temperature, A is the vibration amplitude, and a, b, c, and d are calibration coefficients.

[0009] According to one embodiment of the present invention, in step S5, the preset deviation threshold is 0.003 mm; The comparison logic includes: if the deviation of a single measurement exceeds the standard, automatically repeat the measurement at least twice, and take the median of the multiple measurements for comparison.

[0010] According to one embodiment of the present invention, an adaptive calibration step is further included after step S3: The calibration points are automatically matched according to the model of the tool to be calibrated; if it is a milling cutter, the calibration points include the tip and the shank; if it is a drill bit, the calibration points include the drill tip and the cutting edge.

[0011] According to one embodiment of the present invention, a probe wear monitoring step is further included: The deviation data of the pressure sensor and displacement sensor built into the probe are collected in real time. When the pressure deviation is greater than or equal to 3 N, or the displacement deviation is greater than or equal to 0.003 mm, the probe wear is deemed excessive and an early warning is issued.

[0012] A second aspect of the present invention provides a tool calibration apparatus that applies the method described above, comprising: The oscillating assembly includes a servo motor and a harmonic reducer driven by the servo motor; The measuring arm has its base connected to the output end of the harmonic reducer. The measuring arm is equipped with a temperature sensor and is made of carbon fiber. A bracket for supporting the swing assembly, wherein a vibration sensor is integrated on the bracket; The probe is located at the top of the measuring arm, and the probe integrates a pressure sensor, a displacement sensor, a wear monitoring chip, and an automatic calibration and detection unit. The control system is connected to the swing assembly, the probe, and the environmental sensor, and integrates an environmental compensation module, a probe wear monitoring module, an adaptive calibration module, and an automatic calibration module.

[0013] According to one embodiment of the present invention, the automatic calibration module is communicatively connected to the tool magazine system of the machine tool and is used to receive tool magazine release instructions.

[0014] According to one embodiment of the present invention, the probe is integrated at the end of the measuring arm, and the pressure measurement range of the probe is 0-50 N with an accuracy of ±0.1 N; the displacement measurement range is 0 to 10 mm with an accuracy of ±0.0001 mm.

[0015] According to one embodiment of the present invention, a magnetic dust cover is also included, which is disposed at the stationary position and is used to seal and protect the probe when the measuring arm is in the retracted state.

[0016] According to one embodiment of the present invention, the vibration sensor on the bracket has a measurement range of 0.001 mm to 0.1 mm and an accuracy of ±0.0005 mm, and is used to provide real-time amplitude data for the environmental compensation module.

[0017] According to the tool calibration method provided in the first aspect of the present invention, automated calibration before tool release can accurately identify dimensional deviations caused by foreign objects such as iron filings, preventing unqualified tools from entering the machining process and solving the problem of machining quality fluctuations caused by the lack of pre-calibration in existing technologies. The calibration program is linked to the tool recall process, requiring no manual operation or external calibration equipment. A single calibration takes ≤5 minutes, significantly improving efficiency compared to traditional manual calibration and meeting the high-efficiency production needs of automated machining lines. By using dual temperature and vibration sensors for data acquisition and multinomial fitting algorithm compensation, measurement errors caused by workshop temperature differences and machine tool vibration are eliminated, keeping the overall measurement error within a controllable range and meeting the dimensional calibration requirements of high-precision CNC machining. By employing logic of single-time out-of-range measurement, repeated measurement, and median comparison, random measurement interference is filtered out, avoiding false alarms and missed alarms that could affect production rhythm. The calibration process simultaneously monitors the wear status of the probe, providing early warnings for replacement, reducing accuracy failures caused by excessive probe wear, extending the service life of the calibration device, and reducing maintenance costs. This tool calibration method can automatically identify commonly used machining center tools such as milling cutters and drills, and match the corresponding calibration points and dimensional parameters. It solves the shortcomings of existing technologies that are limited in function and only adaptable to a single type of tool, and greatly improves the versatility and adaptability of the device to different scenarios.

[0018] According to the tool calibration device provided in the second aspect of the present invention, the servo motor, in conjunction with a harmonic reducer, enables precise micron-level swing positioning of the measuring arm, with a positioning accuracy ≤0.005mm, far superior to ordinary motor drive solutions. The measuring arm can swing and retract, and its stationary position does not interfere with the tool magazine, machining parts, or worktable, solving the spatial interference problem of traditional fixed tool setting devices and adapting to various machining center installation layouts. The lightweight, high-rigidity, and deformation-resistant carbon fiber material eliminates measurement errors caused by the deformation of the measuring arm itself. The built-in temperature sensor can collect environmental data in real time, providing accurate input for the compensation algorithm and ensuring measurement stability from a structural perspective. The probe integrates four functions: pressure, displacement, wear monitoring, and automatic calibration. A single contact can complete tool size acquisition, contact determination, and wear detection without the need for multiple probe switching, improving detection efficiency and adapting to harsh environments with cutting fluid, dust, and iron filings pollution, significantly extending its service life. The control system integrates environmental compensation, wear monitoring, adaptive calibration, and automatic calibration functions. It can automatically match different cutting tools such as milling cutters / drills, automatically compensate for environmental errors, automatically detect foreign object adhesion, and automatically warn of probe wear. It achieves full automation of the entire process of call-up, calibration, judgment, and processing, improving calibration efficiency. The magnetic dust cover at the idle station provides fully automatic sealing protection for the probe, avoiding wear from iron filings and coolant adhesion when idle. It eliminates the need for manual disassembly and assembly of dustproof components, significantly reducing the risk of probe contamination and wear, extending probe life, and reducing equipment operation and maintenance costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of the tool calibration method provided by the present invention.

[0021] Figure 2 This is a schematic perspective view of the tool calibration device provided by the present invention.

[0022] Figure label: 100. Swing assembly; 102. Servo motor; 104. Harmonic reducer; 106. Measuring arm; 108. Bracket; 110. Probe. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] The specific terms used in this specification are for illustrative purposes only and are not intended to limit the illustrated embodiments. For example, expressions such as "same" and "identical" not only indicate a strictly identical state, but also indicate a state with tolerances or differences in the degree of functionality. For example, expressions indicating relative or absolute arrangement such as "in a certain direction," "along a certain direction," "side by side," "perpendicular," "centered on," "concentric," or "coaxial" not only strictly indicate such an arrangement, but also indicate a state of relative displacement by tolerances or angles or distances with the same degree of functionality.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] Furthermore, features specified as "first" or "second" may explicitly or implicitly include one or more of those features. In the description of this invention, unless otherwise stated, "multiple" means two or more. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified. In the description of the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, B1 and / or B2 can represent: B1 existing alone, B1 and B2 existing simultaneously, and B2 existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] like Figure 1 As shown, a first aspect of the present invention provides a tool calibration method, which uses a tool calibration device to calibrate a tool installed in a machining tool holder. The method includes the following steps: S1: Obtain machining instructions, execute the tool calling process according to the machining instructions, and retrieve the tool to be machined from the tool magazine to the machining tool holder and clamp it; S2: Trigger the automatic calibration command integrated with the tool recall command to control the swing component 100 to drive the measuring arm 106 from the stationary position to the measuring position; S3: Control the probe 110 set at the end of the measuring arm 106 to collect key dimension parameters of the tool in the machining tool holder, and simultaneously collect environmental data through the environmental compensation module to correct the key dimension parameters in real time. S4: Compare the corrected critical dimension parameters with the pre-stored database of normal dimension parameters for the corresponding tool model for absolute deviation; S5: If the absolute deviation is within the preset deviation threshold, the tool condition is deemed qualified and the machining process begins; if the absolute deviation exceeds the preset deviation threshold, it is determined that there are foreign objects such as iron filings adhering to the contact surface between the tool and the machining tool holder, an alarm signal is issued and machining is suspended.

[0029] According to the tool calibration method provided in the first aspect of the present invention, automated calibration before tool release can accurately identify dimensional deviations caused by iron filings and foreign objects, preventing unqualified tools from entering the machining process and solving the problem of machining quality fluctuations caused by the lack of pre-calibration in existing technologies. The calibration program is linked to the tool recall process, requiring no manual operation or external calibration equipment. A single calibration takes ≤5 minutes, significantly improving efficiency compared to traditional manual calibration and meeting the high-efficiency production needs of automated machining lines. By using dual temperature and vibration sensors for data acquisition and multinomial fitting algorithm compensation, measurement errors caused by workshop temperature differences and machine tool vibration are eliminated, keeping the overall measurement error within a controllable range and meeting the dimensional calibration requirements of high-precision CNC machining. By employing logic of single-time over-limit, repeated measurement, and median comparison, random measurement interference is filtered out, avoiding false alarms and missed alarms that could affect production rhythm. The calibration process simultaneously monitors the wear status of the probe 110, providing early warning for replacement, reducing accuracy failures caused by excessive wear of the probe 110, extending the service life of the calibration device, and reducing maintenance costs. This tool calibration method can automatically identify commonly used machining center tools such as milling cutters and drills, and match the corresponding calibration points and dimensional parameters. It solves the shortcomings of existing technologies that are limited in function and only adaptable to a single type of tool, and greatly improves the versatility and adaptability of the device to different scenarios.

[0030] Please continue reading Figure 1 The tool calibration method provided in the first aspect of the present invention can be used for automated precision calibration of tools in CNC machining centers before they leave the warehouse. It is compatible with various types of machining tools such as milling cutters and drill bits, and can accurately identify the problem of iron filings and foreign matter adhering to the contact surfaces between the tool and the tool holder, and between the tool holder and the spindle. The entire method relies on the tool calibration device of the servo motor 102, the harmonic reducer 104 swinging, the carbon fiber measuring arm 106, the multi-sensor integrated probe 110, and the intelligent compensation calibration system.

[0031] This tool calibration method is mainly achieved through the following steps: Step S1: The machining instructions are code instructions that can be recognized by the machine tool CNC system, integrating tool number and M400 automatic calibration special instructions.

[0032] After the machine tool control system interprets the instructions, it drives the tool magazine robot to take out the tool to be processed from the tool magazine storage position and accurately transfer it to the machining tool holder at the lower end of the spindle. The tool is clamped and coaxially positioned by the hydraulic / pneumatic clamping mechanism. The clamping and positioning accuracy is ≤0.002mm, ensuring the coaxiality of the tool and the machining tool holder.

[0033] Step S2: The automatic calibration command is a dedicated M400 calibration program pre-embedded in the machine tool's CNC system. It is linked with the tool call command and is automatically triggered after the tool is clamped. The swing component 100 consists of a servo motor 102 and a harmonic reducer 104. The positioning accuracy is ≤0.005mm. It drives the carbon fiber measuring arm 106 from the idle storage position in the machine tool's idle area to the measuring position on the side of the machining tool holder. The swing response time is ≤2s.

[0034] When the measuring arm 106 is in the stationary position, the magnetic dust cover automatically seals the probe 110. When it swings to the measuring position, the dust cover automatically detaches without interfering with the measuring operation.

[0035] Step S3: The probe 110 integrates a pressure sensor (measurement range 0~50N, accuracy ±0.1N) and a displacement sensor (measurement range 0~10mm, accuracy ±0.0001mm) at its end. It automatically collects key dimensions according to the tool type: for example, for milling cutters, it collects the tip radius and shank diameter; for drill bits, it collects the drill tip length and cutting edge width.

[0036] The environmental data includes: ambient temperature values ​​collected by the built-in temperature sensor in the measuring arm 106 (measuring range -10℃~80℃, accuracy ±0.1℃) and machine tool vibration amplitude values ​​collected by the integrated vibration sensor in the bracket 108 (measuring range 0.001mm~0.1mm, accuracy ±0.0005mm).

[0037] The environmental compensation module can use a polynomial fitting compensation algorithm. The compensation amount is calculated using the formula: ΔL = a × ΔT, b × A, c, d × ΔT × A, where ΔT is the difference between the actual temperature and the standard temperature of 25℃, and A is the vibration amplitude. The calibration coefficients are set as follows: a = 0.0001 mm / ℃, b = 0.0002 mm / mm, c = 0.00005 mm, d = 0.00002 mm / (℃·mm). The module calculates the compensation amount in real time and corrects key dimensional parameters, completely eliminating measurement errors caused by temperature drift and machine tool vibration.

[0038] Step S4: The control system has a built-in database of normal dimensions for multiple types of cutting tools, and pre-stores standard dimension data for different specifications of milling cutters and drill bits.

[0039] The absolute deviation comparison method is adopted, that is, the corrected measured size minus the standard size. If the deviation of a single measurement exceeds the threshold, the system automatically controls the probe 110 to repeat the measurement twice. After a total of three measurements are completed, the extreme values ​​are removed, the median is taken as the final measured value, and then compared with the standard size to avoid misjudgment caused by random measurement errors.

[0040] Step S5: The preset deviation threshold is 0.003mm. If the absolute deviation is ≤0.003mm, it is determined that there are no foreign objects adhering to the tool and the dimensions are qualified. The system sends a processing permission signal to the machine tool host and automatically enters the cutting process. If the absolute deviation is >0.003mm, it is determined that there are foreign objects such as iron filings adhering to the contact surfaces between the tool and the tool holder, and between the tool holder and the spindle. The control system immediately triggers an audible and visual alarm signal, simultaneously locks the machine tool processing action, displays a foreign object alarm prompt on the CNC system panel, pauses the processing process, and waits for manual cleaning of foreign objects. After cleaning, the calibration process can be retried.

[0041] During the calibration process, wear monitoring of probe 110 is performed simultaneously, and pressure / displacement deviation data are collected in real time. When the pressure deviation is ≥3N or the displacement deviation is ≥0.003mm, a wear warning for probe 110 is triggered to ensure the continuous reliability of calibration accuracy.

[0042] According to an embodiment of the present invention, in step S3, the environmental compensation module corrects the displacement data collected by the probe 110 using a polynomial fitting algorithm, and the calculation formula for the compensation amount ΔL is as follows: ΔL=a×ΔT, b×A, c, d×ΔT×A; Where ΔT is the difference between the actual temperature and the standard temperature, A is the vibration amplitude, and a, b, c, and d are calibration coefficients.

[0043] In one embodiment of the present invention, for example, the standard temperature is set to 25°C, and ΔT is the difference between the actual temperature collected in real time by the temperature sensor built into the measuring arm 106 and 25°C. The temperature sensor has a measurement range of -10°C to 80°C and an accuracy of ±0.1°C.

[0044] A represents the machine tool vibration amplitude acquired in real time by the integrated vibration sensor 108. The vibration sensor has a measurement range of 0.001mm to 0.1mm and an accuracy of ±0.0005mm. The calibration coefficients were determined through multiple sets of experiments: a = 0.0001mm / ℃, b = 0.0002mm / mm, c = 0.00005mm, d = 0.00002mm / (℃·mm), and the goodness of fit R0 is... 2 ≥0.995; The environmental compensation module receives temperature and vibration data in real time, substitutes them into the formula to calculate the compensation amount ΔL, and superimposes the compensation amount onto the original displacement data collected by the probe 110 to complete the real-time correction of the displacement data and eliminate measurement errors caused by temperature changes and machine tool vibration.

[0045] The polynomial fitting compensation algorithm can accurately offset the measurement deviation caused by environmental factors, controlling the measurement error within ±0.002mm, which is far superior to the error level of ±0.008mm of the existing technology, ensuring the high precision and stability of tool size measurement; real-time dynamic compensation requires no manual intervention, adapts to complex working conditions in the processing workshop with temperature difference of 5~15℃ and amplitude ≥0.005mm, and always maintains the measurement accuracy of the calibration device.

[0046] According to one embodiment of the present invention, in step S5, the preset deviation threshold is 0.003 mm; The comparison logic includes: if the deviation of a single measurement exceeds the standard, the measurement is automatically repeated at least twice, and the median of the multiple measurements is compared.

[0047] In one embodiment of the present invention, the preset deviation threshold is set to 0.003mm, which is the criterion for determining whether the tool size is qualified; the automatic calibration module has a database of normal size parameters of various types of tools such as milling cutters and drills, and compares the measured size after environmental compensation with the standard size by absolute deviation.

[0048] If the absolute deviation of a single measurement is greater than 0.003 mm, the control system automatically controls the probe 110 to repeat the measurement twice. After a total of three measurements are completed, the extreme values ​​are removed and the median is taken as the final measured value. Then, it is compared with the standard size to avoid misjudgment caused by the error of a single measurement.

[0049] The high-precision threshold of 0.003mm can accurately identify foreign objects such as iron filings adhering to the contact surfaces between the tool and the tool holder, and between the tool holder and the spindle, thus eliminating machining dimensional deviations caused by foreign objects at the source; the median comparison logic can filter out random measurement interference, reduce false alarm rate, improve the accuracy of tool condition judgment, and ensure reliable calibration results.

[0050] According to one embodiment of the present invention, an adaptive calibration step is further included after step S3: The calibration points are automatically matched according to the model of the tool to be calibrated; if it is a milling cutter, the calibration points include the tip and the shank; if it is a drill bit, the calibration points include the drill tip and the cutting edge.

[0051] In one embodiment of the present invention, the adaptive calibration module has built-in tool type recognition logic. After receiving the tool model information transmitted by the machine tool, it automatically matches the corresponding calibration points and calibration frequency: for milling cutters, it calibrates two points: the tip radius and the shank diameter; for drill bits, it calibrates two points: the tip length and the cutting edge width. According to the calibration points, the control system controls the swing component 100 to precisely drive the probe 110 to move to the corresponding position to complete multi-point calibration. The calibration time for a single point is ≤1 minute, and no manual setting of calibration parameters is required throughout the process.

[0052] The adaptive matching calibration points can be adapted to various types of cutting tools in machining centers, such as milling cutters and drills, solving the problems of limited functionality and poor adaptability in existing technologies. Furthermore, personalized calibration requires no manual intervention, simplifying the calibration process, with a single calibration time of ≤5 minutes, significantly improving efficiency compared to traditional manual calibration.

[0053] According to one embodiment of the present invention, a wear monitoring step for the probe 110 is also included: Real-time acquisition of deviation data from the pressure sensor and displacement sensor built into the probe 110; When the pressure deviation is greater than or equal to 3 N, or the displacement deviation is greater than or equal to 0.003 mm, the wear of probe 110 is determined to be excessive and an early warning is issued.

[0054] In one embodiment of the present invention, the probe 110 wear monitoring module uses a moving average filtering algorithm (window size 10 sets of data) to filter out data interference; it calculates the pressure deviation ΔF = real-time pressure value - standard pressure value (7N) and displacement deviation ΔS = real-time displacement value - standard displacement value in real time; it continuously collects 5 sets of data to calculate the average deviation. When the average pressure deviation is ≥3N or the average displacement deviation is ≥0.003mm, it is determined that the probe 110 wear exceeds the standard, the control system triggers an audible and visual warning and records the warning information; if 3 consecutive sets of data recover to within the threshold, the warning is automatically lifted, and if the warning is continuously issued more than 10 times, the probe 110 is determined to be faulty.

[0055] The intelligent wear monitoring of probe 110 transforms passive maintenance into proactive early warning, avoiding excessive wear of probe 110 that could lead to processing defects and extending the service life of the device by 30%. The threshold judgment logic is accurate and the early warning response is timely, forming a closed loop of prevention, detection, and maintenance, thereby reducing the operation and maintenance costs of the device.

[0056] like Figure 2 As shown, a second aspect of the present invention provides a tool calibration apparatus that applies the method described above, comprising: The swing assembly 100 includes a servo motor 102 and a harmonic reducer 104 driven by the servo motor 102. The measuring arm 106 has its base end connected to the output end of the harmonic reducer 104. The measuring arm 106 is equipped with a temperature sensor and is made of carbon fiber. A bracket 108 is used to support the swing assembly 100, and a vibration sensor is integrated on the bracket 108. The probe 110 is located at the top of the measuring arm 106. The probe 110 integrates a pressure sensor, a displacement sensor, a wear monitoring chip, and an automatic calibration and detection unit. The control system is connected to the swing assembly 100, the probe 110 and the environmental sensor respectively. The control system integrates an environmental compensation module, a probe 110 wear monitoring module, an adaptive calibration module and an automatic calibration module.

[0057] According to the tool calibration device provided in the second aspect of the present invention, the servo motor 102, in conjunction with the harmonic reducer 104, can achieve precise swing positioning of the measuring arm 106 at the micrometer level, with a positioning accuracy ≤0.005mm, far superior to ordinary motor drive solutions. The measuring arm 106 can swing and retract, and its stationary position does not interfere with the tool magazine, machining parts, or worktable, solving the spatial interference problem of traditional fixed tool setting devices and adapting to various machining center installation layouts. The carbon fiber material is lightweight, high-rigidity, and deformation-resistant, eliminating measurement errors caused by the deformation of the measuring arm 106 itself. The built-in temperature sensor can collect environmental data in real time, providing accurate input for the compensation algorithm and ensuring measurement stability from a structural perspective. The probe 110 integrates four functions: pressure, displacement, wear monitoring, and automatic calibration. It can complete tool size acquisition, contact determination, and wear detection with a single contact, eliminating the need for multiple probe switching, improving detection efficiency, adapting to harsh environments with cutting fluid, dust, and iron filings pollution in workshops, and significantly extending its service life. The control system integrates environmental compensation, wear monitoring, adaptive calibration, and automatic calibration functions. It can automatically match different cutting tools such as milling cutters / drills, automatically compensate for environmental errors, automatically detect foreign object adhesion, and automatically warn of probe 110 wear. It realizes full automation of the entire process of calling, calibration, judgment, and processing, improving calibration efficiency. The magnetic dust cover at the idle station provides fully automatic sealing protection for probe 110, avoiding wear from iron filings and coolant adhesion when idle. It eliminates the need for manual disassembly and assembly of dustproof components, significantly reducing the risk of probe 110 contamination and wear, extending the service life of probe 110, and reducing equipment operation and maintenance costs.

[0058] The tool calibration device provided in the second aspect of the present invention is a fully automatic high-precision tool calibration device adapted to CNC machining centers. It is specifically used to perform the aforementioned tool calibration method and can perform pre-shipment dimensional calibration, foreign object identification, and precision compensation for tools such as milling cutters and drills in the machining tool holder. The overall structure is modular and easy to install.

[0059] The swing assembly 100 is composed of a servo motor 102 and a harmonic reducer 104 connected coaxially. The servo motor 102 is a high-precision closed-loop control motor, and the transmission backlash of the harmonic reducer 104 is ≤0.5 arcminutes. The two can be rigidly connected by a flange.

[0060] The swing assembly 100 is fixed on the top of the bracket 108. The output end of the harmonic reducer 104 is rigidly locked to the base end of the measuring arm 106, driving the measuring arm 106 to achieve 0~90° swing switching. The station switching positioning accuracy is ≤0.005mm, the swing response time is ≤2s, and it can stably drive the measuring arm 106 to accurately switch between the stationary station and the measuring station.

[0061] The base of the measuring arm 106 is fixedly connected to the output end of the harmonic reducer 104. The whole arm is integrally molded from carbon fiber composite material. Compared with the traditional metal measuring arm 106, the deformation rate is reduced by 80%, making it lightweight, highly rigid, and resistant to vibration and deformation.

[0062] The measuring arm 106 has a pre-embedded temperature sensor with a temperature range of -10℃ to 80℃ and a detection accuracy of ±0.1℃. It collects the ambient temperature of the measuring arm 106 in real time and transmits it to the control system. The length of the measuring arm 106 is designed to fit the space of the machining center, and the end extends straight for mounting the probe 110.

[0063] The bracket 108 is an integral rigid support base, which can be milled from high-strength aluminum alloy. It has a machine tool mounting flange at the bottom and can be fixed to a preset station next to the worktable, column, or tool magazine of the machining center by bolts.

[0064] The bracket 108 has a hollowed-out middle section for weight reduction, and a rigid top support for the swing assembly 100. The vibration sensor is integrated and fixed on the inner side of the bottom of the bracket 108. The vibration measurement range is 0.001mm~0.1mm, the detection accuracy is ±0.0005mm, and the vibration amplitude data of the machine tool operation is collected in real time to provide the original signal for environmental compensation.

[0065] The probe 110 is rigidly locked to the top end of the measuring arm 106, forming an integrated detection probe. Internally, it coaxially integrates a pressure sensor, a displacement sensor, a wear monitoring chip, and an automatic calibration detection unit. The pressure sensor has a measurement range of 0~50N and a detection accuracy of ±0.1N, used to detect the contact pressure between the probe 110 and the tool; the displacement sensor has a measurement range of 0~10mm and a detection accuracy of ±0.0001mm, used to collect critical tool displacement data; the wear monitoring chip collects sensor deviation signals in real time, and the automatic calibration detection unit is responsible for signal preprocessing and transmission; the probe 110 is externally protected by a stainless steel sealing sleeve with an IP67 protection rating, suitable for environments contaminated with cutting fluid and metal filings.

[0066] The control system is an embedded CNC control unit, fixedly installed on the side of the bracket 108 or inside the machine tool electrical control cabinet. It is electrically connected to the swing assembly 100, probe 110, temperature sensor, and vibration sensor via the Profinet industrial bus. The control system integrates four major functional modules: The environmental compensation module has a built-in polynomial fitting compensation algorithm that corrects the measured dimensions in real time based on temperature and vibration data. The 110 probe wear monitoring module analyzes pressure / displacement deviation data in real time for otology, triggering an early warning when the deviation exceeds the standard. The adaptive calibration module can automatically match calibration points and parameters according to the tool model; The automatic calibration module can pre-store a database of standard tool dimensions and link with the machine tool magazine system to receive outbound commands and trigger the calibration process.

[0067] In addition, the tool calibration device is equipped with a magnetic dust cover, which is fixedly installed at the stop position of the measuring arm 106. The magnetic response time is ≤0.5s. When the measuring arm 106 is stored in the stop position, the dust cover automatically magnetically seals and wraps the probe 110, preventing contamination by iron filings and coolant. When the measuring arm 106 is swung to the measuring position, the dust cover automatically detaches without affecting the operation of the probe 110.

[0068] According to one embodiment of the present invention, the automatic calibration module is communicatively connected to the tool magazine system of the machine tool and is used to receive tool magazine release commands.

[0069] In one embodiment of the present invention, the automatic calibration module can communicate with the machine tool tool magazine system via an industrial bus and receive tool magazine release instructions in real time. At the same time the tool is retrieved from the tool magazine, the tool magazine system simultaneously sends a trigger signal to the automatic calibration module, and the automatic calibration module immediately starts the workstation switching and dimensional measurement process to achieve seamless linkage between tool release and calibration.

[0070] It triggers the calibration process in conjunction with the tool magazine system, realizing fully automated calibration of tools before processing, eliminating the need for manual program startup and improving the efficiency of the processing line; it responds to the outbound command in real time, ensuring that each tool is calibrated before use, and completely preventing unqualified tools from entering the processing stage.

[0071] According to one embodiment of the present invention, the probe 110 is integrated at the end of the measuring arm 106, and the pressure measurement range of the probe 110 is 0-50 N with an accuracy of ±0.1 N; the displacement measurement range is 0 to 10 mm with an accuracy of ±0.0001 mm.

[0072] In one embodiment of the present invention, the probe 110 is an integrated structure, securely mounted on the end of the carbon fiber measuring arm 106, and internally integrates a pressure sensor, a displacement sensor, a wear monitoring chip, and an automatic calibration detection unit; the pressure sensor has a measurement range of 0~50N and a detection accuracy of ±0.1N, and is used to collect the contact pressure between the probe 110 and the tool; the displacement sensor has a measurement range of 0~10mm and a detection accuracy of ±0.0001mm, and is used to collect tool size displacement data; all sensor signals are synchronously transmitted to the control system to realize multi-dimensional data acquisition.

[0073] The Probe 110 high-precision sensor can meet the micron-level tool size calibration requirements and is suitable for high-precision CNC machining scenarios. Its compact, integrated structure saves machine tool space, provides strong data acquisition synchronization, and avoids precision loss caused by assembling multiple components.

[0074] According to one embodiment of the present invention, a magnetic dust cover is also included, which is disposed at the stationary position to seal and protect the probe 110 when the measuring arm 106 is in the retracted state.

[0075] In one embodiment of the present invention, the magnetic dust cover is made of a flexible sealing material with a magnetic response time of ≤0.5s. After the measuring arm 106 completes calibration, it swings to the stop position, and the dust cover automatically magnetically attaches to the end of the measuring arm 106, completely sealing and wrapping the probe 110 to prevent iron filings, coolant, dust and other contaminants from adhering to the surface of the probe 110. When the measuring arm 106 switches to the measuring position, the dust cover automatically demagnetizes and reattaches, without affecting the normal operation of the probe 110.

[0076] The magnetic dust cover provides fully automatic sealing protection for the probe 110 when it is not in use, preventing contamination and wear of the probe 110 and extending its service life. It eliminates the need for manual disassembly and assembly of the dust cover, making it compatible with automated machining processes and addressing the shortcomings of existing technologies that do not provide dust protection for the probe 110.

[0077] According to one embodiment of the present invention, the vibration sensor on the bracket 108 has a measurement range of 0.001 mm to 0.1 mm and an accuracy of ±0.0005 mm, and is used to provide real-time amplitude data for the environmental compensation module.

[0078] In one embodiment of the present invention, the vibration sensor is fixedly integrated into the bottom of the bracket 108 of the calibration device, directly collecting the real-time vibration amplitude during machine tool operation, with a measurement range of 0.001mm~0.1mm and a detection accuracy of ±0.0005mm; the sensor communicates with the environmental compensation module in real time through a signal line, synchronously transmitting the amplitude data to the algorithm unit, providing accurate input parameters for the polynomial fitting compensation formula.

[0079] High-precision vibration sensors can accurately capture minute vibration signals of machine tools, providing reliable data support for environmental compensation algorithms and further improving the accuracy of measurement error correction. The sensor is integrated on the bracket 108, which is stable, has strong anti-interference capabilities, and is suitable for stable operation under machine tool vibration conditions.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tool calibration method, characterized in that, The method of using a tool calibration device to calibrate tools installed in a machining tool holder includes the following steps: S1: Obtain the machining instruction, execute the tool calling process according to the machining instruction, and retrieve the tool to be processed from the tool magazine to the machining tool holder and clamp it; S2: Triggers an automatic calibration command integrated with the tool recall command, controlling the swing component to drive the measuring arm to swing from the stationary position to the measuring position; S3: Control the probe set at the end of the measuring arm to collect key dimension parameters of the tool in the machining tool holder, and simultaneously collect environmental data through the environmental compensation module to correct the key dimension parameters in real time; S4: Compare the corrected critical dimension parameters with the pre-stored database of normal dimension parameters for the corresponding tool model for absolute deviation; S5: If the absolute deviation is within the preset deviation threshold, the tool condition is deemed qualified and the machining process begins; if the absolute deviation exceeds the preset deviation threshold, it is determined that there are foreign objects such as iron filings adhering to the contact surface between the tool and the machining tool holder, an alarm signal is issued and machining is suspended.

2. The tool calibration method according to claim 1, characterized in that, In step S3, the environmental compensation module corrects the displacement data collected by the probe using a polynomial fitting algorithm. The calculation formula for the compensation amount ΔL is as follows: ΔL=a×ΔT+b×A+c+d×ΔT×A; Where ΔT is the difference between the actual temperature and the standard temperature, A is the vibration amplitude, and a, b, c, and d are calibration coefficients.

3. The tool calibration method according to claim 1, characterized in that, In step S5, the preset deviation threshold is 0.003 mm; The comparison logic includes: if the deviation of a single measurement exceeds the standard, automatically repeat the measurement at least twice, and take the median of the multiple measurements for comparison.

4. The tool calibration method according to claim 1, characterized in that, Step S3 is followed by an adaptive calibration step: The calibration points are automatically matched according to the model of the tool to be calibrated; if it is a milling cutter, the calibration points include the tip and the shank; if it is a drill bit, the calibration points include the drill tip and the cutting edge.

5. The tool calibration method according to claim 1, characterized in that, It also includes a probe wear monitoring step: The deviation data of the pressure sensor and displacement sensor built into the probe are collected in real time. When the pressure deviation is greater than or equal to 3 N, or the displacement deviation is greater than or equal to 0.003 mm, the probe wear is deemed excessive and an early warning is issued.

6. A tool calibration apparatus applying the method according to any one of claims 1 to 5, characterized in that, include: The oscillating assembly includes a servo motor and a harmonic reducer driven by the servo motor; The measuring arm has its base connected to the output end of the harmonic reducer. The measuring arm is equipped with a temperature sensor and is made of carbon fiber. A bracket for supporting the swing assembly, wherein a vibration sensor is integrated on the bracket; The probe is located at the top of the measuring arm, and the probe integrates a pressure sensor, a displacement sensor, a wear monitoring chip, and an automatic calibration and detection unit. The control system is connected to the swing assembly, the probe, and the environmental sensor, and integrates an environmental compensation module, a probe wear monitoring module, an adaptive calibration module, and an automatic calibration module.

7. The tool calibration device according to claim 6, characterized in that, The automatic calibration module is connected to the machine tool's tool magazine system and is used to receive tool magazine release commands.

8. The tool calibration device according to claim 6, characterized in that, The probe is integrated at the end of the measuring arm, and the pressure measurement range of the probe is 0-50 N with an accuracy of ±0.1 N; the displacement measurement range is 0 to 10 mm with an accuracy of ±0.0001 mm.

9. The tool calibration device according to claim 6, characterized in that, It also includes a magnetic dust cover, which is installed at the stationary position to seal and protect the probe when the measuring arm is in the retracted state.

10. The tool calibration device according to claim 6, characterized in that, The vibration sensor on the bracket has a measurement range of 0.001 mm to 0.1 mm and an accuracy of ±0.0005 mm, and is used to provide real-time amplitude data for the environmental compensation module.

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