A test system and method for quickly identifying boring stiffness coefficient

Abstract

The present invention discloses a test system and method for quickly identifying a boring stiffness coefficient. The system comprises an excitation module, a force measurement module, and a displacement measurement module. The excitation module comprises a test computer, a signal generator, a power amplifier, a contact electromagnetic exciter, and an air-cooled air pump. The force measurement module comprises a pressure-variable force sensor, a charge amplifier, a force signal acquisition box, and a test computer. The pressure-variable force sensor is installed between a workbench and a workpiece to be measured, the output end of the pressure-variable force sensor is connected to the input end of the charge amplifier via a connecting line, the output end of the charge amplifier is connected to the input end of the force signal acquisition box via a connecting line, and the output end of the force signal acquisition box is connected to the test computer via a USB interface. The displacement measurement module comprises an eddy current displacement sensor, a displacement signal acquisition box, and a test computer. Three eddy current displacement sensors are respectively installed at a measured point on the end of the workpiece to be measured, a front end of a boring tool, and a root of the boring tool.

Description

Technical Field

[0001] The invention relates to the technical field of machine tool cutting, and in particular to a test system and method for quickly identifying a boring stiffness coefficient. Background Art

[0002] As core infrastructure in the equipment manufacturing industry, machine tools are crucial to a country's industrial strength. They are not only crucial tools for manufacturing a wide range of mechanical products, but also play an indispensable role in numerous sectors, including defense, aerospace, automotive, electronics, and energy. The tool and workpiece, as the final components of a machine tool structure, interact during machining, creating a major source of machine tool vibration. During the cutting process, the contact between the tool and the workpiece generates complex dynamic behavior, which directly impacts the machine tool's operational stability and machining accuracy. To more accurately predict cutting forces, it is essential to precisely identify the cutting stiffness coefficients of the tool and workpiece. Accurately measuring and analyzing these coefficients provides more reliable data support for cutting force models, enabling dynamic simulation and optimization of the machine tool cutting process. Accurate simulation not only improves machining quality and efficiency, but also effectively reduces vibration-induced machining errors and tool wear, thereby extending the life of machine tools and tools. This is crucial for advancing the overall level and technological capabilities of the manufacturing industry.

[0003] Currently, the main method for identifying the cutting stiffness coefficient is to conduct a large number of cutting experiments by varying cutting parameters, including back-cut depth and feed rate, recording the three-dimensional cutting forces, and formulating empirical formulas. This method is limited by the need to re-run cutting with different tools, resulting in a large amount of experimental work. Furthermore, in boring, the cutting edge continuously rotates around the circumference, and the direction of the cutting force also changes continuously. Using a fixed-direction force measuring instrument alone cannot measure the cutting forces in each direction. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a test system and method for quickly identifying the boring stiffness coefficient, thereby realizing phase calibration during the boring process, overcoming the problem of being unable to measure the cutting forces in each direction during the boring process, and on this basis realizing the rapid identification of the boring stiffness coefficient of any boring tool and greatly reducing the experimental workload.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A test system for quickly identifying boring stiffness coefficients includes a vibration excitation module, a force measurement module, and a displacement measurement module. The vibration excitation module is composed of a test computer, a signal generator, a power amplifier, a contact electromagnetic vibrator, and an air-cooling air pump. The test computer is connected to the signal generator via a USB interface, the output end of the signal generator is connected to the input end of the power amplifier via a connecting line, the output end of the power amplifier is connected to the signal input end of the contact electromagnetic vibrator via a connecting line, and the air-cooling air pump is connected to the cooling port of the contact electromagnetic vibrator via a hose.

[0007] The force measurement module consists of a pressure-variable force sensor, a charge amplifier, a force signal acquisition box, and a test computer. The pressure-variable force sensor is installed between the workbench and the workpiece to be measured. The output end of the pressure-variable force sensor is connected to the input end of the charge amplifier via a connecting line. The output end of the charge amplifier is connected to the input end of the force signal acquisition box via a connecting line. The output end of the force signal acquisition box is connected to the test computer via a USB interface.

[0008] The displacement measurement module consists of an eddy current displacement sensor, a displacement signal acquisition box, and a second test computer. The three eddy current displacement sensors are installed at the measured point on the workpiece, the front end of the boring tool, and the root of the boring tool, and are connected to the displacement signal acquisition box equipped with an NI acquisition card through connecting cables. The output end of the displacement signal acquisition box is connected to the second test computer through a USB interface.

[0009] Furthermore, before the experiment, a 0.5mm thick thin iron sheet with a length of 5mm and a width of 2mm was pasted on the root of the boring tool. Its position on the circumference of the boring tool was consistent with that of the boring blade. The eddy current displacement sensors located at the measured point at the end of the workpiece and the front end of the boring tool were used to measure the vibration displacement of the measured point at the end of the workpiece and the front end of the boring tool respectively. The eddy current displacement sensor at the root of the boring tool was aligned with the thin iron sheet to record the phase during the rotation of the boring tool.

[0010] The present invention also provides a method for quickly identifying the boring stiffness coefficient. The test system based on the above-mentioned method for quickly identifying the boring stiffness coefficient includes:

[0011] Step 1: Based on the metal cutting theory, a dynamic cutting force model is established from the perspective of cutting area and cutting line length. The cutting stiffness coefficient includes the radial, tangential, and axial cutting stiffness coefficients of the cutting area and the radial, tangential, and axial cutting stiffness coefficients of the cutting line length.

[0012] Step 2: According to the dynamic cutting force model, the dynamic cutting force is analyzed by changing the cutting parameters, and it is found that the ratio of the dynamic cutting force to the change in the back-cut amount is linearly related to the feed rate. The ratio of the dynamic cutting force to the change in the back-cut amount is expressed as a function of the feed rate; the cutting parameters include the back-cut amount and the feed rate;

[0013] Step 3: The signal generator generates a stable sinusoidal excitation digital signal with a frequency of 160 Hz, which is converted into an analog sinusoidal signal by the built-in digital-to-analog converter. The analog sinusoidal signal is amplified by the power amplifier and input to the input end of the contact electromagnetic exciter. The frequency is the natural frequency of the workpiece after being installed in the cutting position.

[0014] Step 4: The contact electromagnetic vibrator drives the internal connecting rod to vibrate according to the input analog sinusoidal signal. The connecting rod is connected to the workpiece through a thread. The vibration of the connecting rod drives the workpiece to vibrate. The boring stiffness coefficient is identified by converting the back-cut amount under steady-state cutting into the back-cut amount under dynamic cutting during the cutting process.

[0015] Step 5: Use a pressure-variable force sensor to record the force on the workpiece during the experiment, and use three eddy current displacement sensors to record the measured point position of the workpiece end, the vibration displacement of the boring tool front end, and the boring tool rotation phase;

[0016] Step 6: Through the rotation phase of the boring tool, extract the vibration displacement data of the same phase part at different times and combine it with the corresponding force signal data to calculate the relationship between vibration displacement and cutting force under different cutting conditions, and calculate the boring stiffness coefficient through linear regression.

[0017] Furthermore, the influence of cutting area and cutting line length on dynamic cutting force in step 1 is expressed as the following formula:

[0018]

[0019] Where A is the cutting area, L is the cutting line length, dF t 、dF r 、dF a They are radial, tangential and axial cutting force components, respectively, k At 、k Ar 、k Aa are the radial, tangential and axial cutting stiffness coefficients of the cutting area, k Lt 、k Lr 、k La are the cutting stiffness coefficients in the radial, tangential and axial directions of the cutting line length respectively;

[0020] By applying an external excitation force to the workpiece, the workpiece undergoes simple harmonic vibration, which can be expressed as:

[0021] x1=A1 sin(ω1t)

[0022] A1 is the vibration amplitude of the workpiece being measured, ω1 is the vibration angular velocity of the workpiece being measured;

[0023] The vibration of the boring tool in the exciting direction is recorded as:

[0024]

[0025] A2 is the vibration amplitude of the boring tool, ω2 is the vibration angular velocity of the boring tool, is the phase difference between the vibration of the workpiece being measured and the vibration of the boring tool;

[0026] The relative displacement of the boring tool and the workpiece is expressed as:

[0027]

[0028] Furthermore, since the boring tool is constantly rotating during the boring process, when the simple harmonic vibration direction of the workpiece is aligned with the cutting direction of the machine tool,

[0029] When vertical, the cutting depth f is expressed as:

[0030]

[0031] f' is the depth of cut under steady-state cutting;

[0032] The change in back cutting depth is expressed as:

[0033]

[0034] The cutting area and cutting line length are expressed as:

[0035]

[0036] s is the feed per revolution, κ r is the main deflection angle;

[0037] The change in cutting area is expressed as:

[0038]

[0039] Cutting line length variation:

[0040]

[0041] The dynamic cutting force model is expressed as:

[0042]

[0043] Furthermore, the testing process in step 5 is divided into three parts:

[0044] The first is the idling stage of the machine tool spindle. During this stage, no cutting is done and the exciter is not turned on, so that the machine tool background noise can be recorded through the eddy current displacement sensor.

[0045] The second stage is when the machine tool spindle is idling and the exciter is turned on. In this stage, the magnitude and phase of the exciting force and the magnitude and phase of the displacement vibration of the workpiece are recorded through the pressure variable force sensor and the eddy current displacement sensor.

[0046] Finally, the workpiece under test is cut while being excited, and the cutting force signal, vibration signals of the workpiece under test and boring tool, and phase records are recorded.

[0047] The present invention also provides an electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of a method for rapidly identifying a boring stiffness coefficient when executing the program.

[0048] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of the method for rapidly identifying the boring stiffness coefficient are implemented.

[0049] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0050] 1. Improved experimental efficiency: Traditional methods require multiple changes in cutting parameters and a large number of experiments. This invention introduces a dynamic back-cut cutting method to significantly reduce the number of experimental groups and workload, achieve rapid identification of the boring stiffness coefficient, and save time and resources.

[0051] 2. Accurate identification of cutting stiffness coefficient: This invention constructs a dynamic cutting force model based on metal cutting theory, combines the influence of cutting area and cutting line length on cutting force, and accurately identifies radial, tangential and axial cutting stiffness coefficients through variable feed rate experiments, ensuring data reliability and accuracy, and providing higher accuracy for cutting force prediction.

[0052] 3. Dynamic cutting condition simulation: The system simulates the cutting condition of dynamic back-cut through sinusoidal excitation force, extending the steady-state conditions to dynamic conditions, thereby accurately analyzing the dynamic behavior in the complex cutting process, helping to improve the design and optimization of cutting parameters and enhance the quality and efficiency of machine tool processing.

[0053] 4. Multi-directional cutting force measurement: The test system is designed with the function of recording the tool rotation angle. By combining multiple sensors to measure the workpiece force and tool displacement, it can accurately measure the cutting force in each direction when the cutting edge rotates continuously around the circumference and the cutting force direction also changes continuously. This solves the problem of the cutting force direction changing with the tool rotation and cannot be accurately measured, thereby achieving high-precision identification of the cutting stiffness coefficient of the cutting force in each direction.

[0054] 5. Vibration error control: By accurately acquiring the dynamic stiffness characteristics of the tool-workpiece contact area, the present invention can effectively reduce machining errors caused by vibration, improve machining stability and surface quality, and extend the service life of the machine tool and tool.

[0055] 6. Wide range of applications: The test system of the present invention is applicable to various boring tools and workpieces, can be quickly adapted to different processing scenarios, has wide practicality and promotion value, and is of great significance to improving processing accuracy and reducing costs in the manufacturing industry.

[0056] In summary, the present invention significantly reduces the amount of experiments while achieving accurate analysis of complex boring dynamic behavior, providing strong support for cutting process optimization and manufacturing technology advancement. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a structural schematic diagram of the test system of the present invention.

[0058] Figure 2 Schematic diagram of the process of the present invention.

[0059] Figure 3 Schematic diagram of the cutting process.

[0060] Figures 4a to 4c The cutting force test and simulation results in the x, y and z directions under variable feed rate are shown respectively. DETAILED DESCRIPTION

[0061] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0062] like Figure 1 As shown, this embodiment provides a test system for quickly identifying the boring stiffness coefficient, including an excitation module, a force measurement module, and a displacement measurement module; the excitation module is composed of a test computer, a signal generator, a power amplifier, an exciter, and an air-cooled air pump. The exciter adopts a contact electromagnetic exciter. The test computer is connected to the signal generator via a USB interface. The output interface of the signal generator is connected to the input of the power amplifier via a connecting line. The output of the power amplifier is connected to the signal input of the contact electromagnetic exciter via a connecting line. The air-cooled air pump is connected to the cooling port of the contact electromagnetic exciter via a hose.

[0063] The power amplifier amplifies the weak sinusoidal signal generated by the signal generator to drive the contact electromagnetic exciter. The air-cooling air pump pumps air into the coil of the contact electromagnetic exciter to cool the electromagnetic coil and prevent it from overheating and damage.

[0064] The force measurement module consists of a compression-type force sensor, a charge amplifier, a force signal acquisition box, and a test computer. The compression-type force sensor, installed between the workbench and the workpiece, can accurately measure the three-dimensional force acting on the workpiece. The output of the compression-type force sensor is connected to the input of the charge amplifier via a cable, which in turn is connected to the input of the force signal acquisition box via a cable. The output of the force signal acquisition box is connected to the test computer via a USB port.

[0065] The displacement measurement module consists of eddy current displacement sensors, a displacement signal acquisition box, and test computer 2. Three eddy current displacement sensors are installed at the measured point on the workpiece end, the front end of the boring tool, and the root of the boring tool. They are connected to the displacement signal acquisition box, which is equipped with an NI acquisition card, via cables. The output of the displacement signal acquisition box is connected to test computer 2 via a USB port.

[0066] Before the experiment, a 0.5mm thick thin iron sheet with a length of 5mm and a width of 2mm was pasted on the root of the boring tool. Its position on the circumference of the boring tool was consistent with the boring blade. Three eddy current displacement sensors were installed at the measured point on the workpiece end, the front end of the boring tool and the root of the boring tool. The purpose of the first two was to measure the vibration displacement of the measured point on the workpiece end and the front end of the boring tool. The latter was aimed at the thin iron sheet and was used to record the phase through displacement data during the rotation of the boring tool.

[0067] Preferably, this embodiment further provides a method for quickly identifying a boring stiffness coefficient, comprising:

[0068] Step 1: Based on the metal cutting theory, a dynamic cutting force model is established from the perspective of cutting area and cutting line length. The cutting stiffness coefficient includes the radial, tangential, and axial cutting stiffness coefficients of the cutting area and the radial, tangential, and axial cutting stiffness coefficients of the cutting line length.

[0069] According to the dynamic cutting force model, by changing the cutting parameters and analyzing the dynamic cutting force, it can be found that the ratio of the dynamic cutting force to the change in the back cutting amount is linearly related to the feed rate, and the ratio of the dynamic cutting force to the change in the back cutting amount is expressed as a function of the feed rate; the cutting parameters include the back cutting amount and the feed rate;

[0070]

[0071] Where k At 、k Ar 、k Aa are the radial, tangential and axial cutting stiffness coefficients of the cutting area, k Lt 、k Lr 、k La are the radial, tangential and axial cutting stiffness coefficients of the cutting line length respectively; s is the feed per revolution, κ rThe experimental conditions of each group of cutting experiments are that the back cutting depth remains unchanged without vibration, the spindle speed remains unchanged, and only the feed speed is changed.

[0072] Step 2: Before the experiment, adjust the three eddy current sensors to the appropriate measurement distance and align them with the radial position of the boring tool. Set the acquisition frequency of the force measurement module and the displacement measurement module to the same value and try to take the maximum value. Turn on the pressure-variable force sensor and eddy current displacement sensor for synchronous recording.

[0073] Start the spindle under the conditions of step 2. This is the idling stage of the machine tool spindle. No cutting is done and the exciter is not turned on during this stage. The purpose is to record the machine tool background noise through the displacement sensor. Then start moving the worktable at a certain feed speed to record the vibration caused by the machine tool feed system.

[0074] Step 3: Turn on the air cooling pump of the excitation module and pump air into the coil of the contact electromagnetic exciter to ensure good heat dissipation of the exciter. The signal generator generates a stable sinusoidal excitation digital signal with a frequency of 160Hz. The built-in digital-to-analog converter converts it into an analog sinusoidal signal. The analog sinusoidal signal is amplified by the power amplifier and input to the input end of the contact electromagnetic exciter. The frequency is the natural frequency of the workpiece after it is installed in the cutting position.

[0075] The contact electromagnetic vibrator drives the internal connecting rod to vibrate according to the input sinusoidal signal. The connecting rod is connected to the workpiece through a thread. The vibration of the connecting rod drives the workpiece to vibrate. During the cutting process, the back-cutting amount under steady-state cutting is converted into the back-cutting amount under dynamic cutting.

[0076] Step 4: Use a pressure-variable force sensor to record the force on the workpiece during the experiment, and use three eddy current displacement sensors to record the measured point position at the workpiece end, the vibration displacement at the front end of the boring tool, and the boring tool rotation phase;

[0077] The testing process is divided into three parts. The first is the idling phase of the machine tool spindle. During this phase, no cutting is performed and the vibrator is not activated. The purpose is to record the machine tool noise floor using the displacement sensor. The second phase is the idling phase of the machine tool spindle with the vibrator activated. During this phase, the magnitude and phase of the excitation force on the workpiece, as well as the magnitude and phase of the displacement vibration, are recorded using a pressure-variable force sensor and an eddy-current displacement sensor. The third phase is the cutting phase while the vibration is being performed, recording the cutting force signal, the vibration signals of the workpiece and tool, and the phase.

[0078] Step 5: Dynamic cutting experiments were carried out at a fixed back cutting depth of 0.1 mm, a cutting speed of 240 mm / min, and feed speeds of eight groups of 0.02 mm / r, 0.04 mm / r, 0.06 mm / r, 0.08 mm / r, 0.1 mm / r, 0.12 mm / r, 0.14 mm / r, and 0.16 mm / r.

[0079] Step six, experimental data processing, first, based on the phase signal, intercept the data of the stage perpendicular to the tool cutting direction and the excitation direction, including the three-axis cutting force signals of the X-axis, Y-axis, and Z-axis and the vibration displacement signals of the workpiece and tool. Based on the machine tool background noise recorded during the idling phase of the machine tool spindle, Fourier filtering is used to retain the signal in the excitation frequency band and filter out other interference signals.

[0080] Step seven, after obtaining the filtered signal, use the least squares method to fit the three-dimensional exciting force and vibration displacement of the workpiece when the machine tool is not started and only under the action of the exciter, based on the data segment when the machine tool spindle is idling and the exciter is turned on. Fit it into a sinusoidal signal, and record the amplitude of the exciting force, the amplitude of the vibration displacement, and the phase difference between the two.

[0081] Based on the data from the excitation and cutting phase, the changes in cutting force due to dynamic cutting are fitted based on the three-dimensional excitation force signal fitted during the uncut phase. The three-dimensional cutting force is then fitted into a sinusoidal signal, and the cutting force amplitude is recorded. Similarly, based on the workpiece vibration displacement signal fitted during the uncut phase, the changes in workpiece tool vibration displacement due to dynamic cutting are fitted into a sinusoidal signal, and the amplitude of the workpiece tool vibration displacement is recorded.

[0082] Step 8: Calculate the cutting stiffness under the working condition by calculating the amplitude ratio between the dynamic cutting force signal and the tool-workpiece displacement. Calculate the cutting stiffness at four points under the same working condition and take the average value as the cutting stiffness under the working condition. Calculate the cutting stiffness of each group and bring it into the dynamic cutting force formula to obtain the cutting force stiffness coefficients in three directions. Figure 4a 、 Figure 4b and Figure 4c As shown in the figure, the experimental cutting force based on the above method is consistent with the simulation results of the boring stiffness coefficient cutting force model, which provides a method for quickly identifying the boring stiffness coefficient.

[0083] Preferably, the embodiments of the present application also provide a specific implementation of an electronic device capable of implementing all steps of the method for rapidly identifying the boring stiffness coefficient in the above embodiment, and the electronic device specifically includes the following contents:

[0084] Processor, memory, communications interface, and bus;

[0085] Among them, the processor, memory, and communication interface communicate with each other through the bus; the communication interface is used to realize information transmission between related devices such as server-side devices, metering devices, and user-side devices.

[0086] The processor is used to call the computer program in the memory, and when the processor executes the computer program, all the steps of the method for quickly identifying the boring stiffness coefficient in the above embodiment are implemented.

[0087] An embodiment of the present application also provides a computer-readable storage medium that can implement all the steps of the method for quickly identifying the boring stiffness coefficient in the above embodiment. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements all the steps of the method for quickly identifying the boring stiffness coefficient in the above embodiment.

[0088] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0089] Although the present application provides method operation steps such as embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-creative work. The order of steps listed in the embodiments is only one way of executing the steps among many steps and does not represent the only execution order. When an actual device or client product is executed, it can be executed in the order shown in the embodiments or the drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0090] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0091] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0093] The present invention is not limited to the embodiments described above. The above description of the specific embodiments is intended to describe and illustrate the technical solutions of the present invention. The above specific embodiments are merely illustrative and not restrictive. Without departing from the scope of the present invention and the scope of protection of the claims, those skilled in the art may make various specific modifications based on the teachings of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A method for quickly identifying the boring stiffness coefficient, characterized in that: include: Step 1: Based on metal cutting theory, a dynamic cutting force model is established from the perspective of cutting area and cutting line length. The cutting stiffness coefficient includes the radial, tangential, and axial cutting stiffness coefficients of the cutting area and the radial, tangential, and axial cutting stiffness coefficients of the cutting line length. The influence of cutting area and cutting line length on dynamic cutting force is expressed as the following formula: ； In the formula is the cutting area, is the cutting line length, are the radial, tangential and axial cutting force components respectively, are the radial, tangential and axial cutting stiffness coefficients of the cutting area, are the cutting stiffness coefficients in the radial, tangential and axial directions of the cutting line length respectively; By applying an external excitation force to the workpiece, the workpiece undergoes simple harmonic vibration, which can be expressed as: ； is the vibration amplitude of the workpiece being measured, is the vibration angular velocity of the workpiece being measured; The vibration of the boring tool in the exciting direction is recorded as: ； is the vibration amplitude of the boring tool, is the boring tool vibration angular velocity, is the phase difference between the vibration of the workpiece being measured and the vibration of the boring tool; The relative displacement of the boring tool and the workpiece is expressed as: ； Since the boring tool is constantly rotating during the boring process, when the simple harmonic vibration direction of the workpiece is perpendicular to the cutting direction of the machine tool, the cutting depth is Expressed as: ； is the depth of cut under steady-state cutting; The change in back cutting depth is expressed as: ； The cutting area and cutting line length are expressed as: ； is the feed per revolution, is the main deflection angle; The change in cutting area is expressed as: ； Cutting line length variation: ； The dynamic cutting force model is expressed as: ； Step 2: According to the dynamic cutting force model, the dynamic cutting force is analyzed by changing the cutting parameters, and it is found that the ratio of the dynamic cutting force to the change in the back-cut amount is linearly related to the feed rate. The ratio of the dynamic cutting force to the change in the back-cut amount is expressed as a function of the feed rate; the cutting parameters include the back-cut amount and the feed rate; Step 3: The signal generator generates a stable sinusoidal excitation digital signal with a frequency of 160 Hz, which is converted into an analog sinusoidal signal by the built-in digital-to-analog converter. The analog sinusoidal signal is amplified by the power amplifier and input to the input end of the contact electromagnetic exciter. The frequency is the natural frequency of the workpiece after being installed in the cutting position. Step 4: The contact electromagnetic vibrator drives the internal connecting rod to vibrate according to the input analog sinusoidal signal. The connecting rod is connected to the workpiece through a thread. The vibration of the connecting rod drives the workpiece to vibrate. The boring stiffness coefficient is identified by converting the back-cut amount under steady-state cutting into the back-cut amount under dynamic cutting during the cutting process. Step 5: Use a pressure-variable force sensor to record the force on the workpiece during the experiment, and use three eddy current displacement sensors to record the measured point position of the workpiece end, the vibration displacement of the boring tool front end, and the boring tool rotation phase; Step 6: Through the rotation phase of the boring tool, extract the vibration displacement data of the same phase part at different times and combine it with the corresponding force signal data to calculate the relationship between vibration displacement and cutting force under different cutting conditions, and calculate the boring stiffness coefficient through linear regression.

2. The method for quickly identifying the boring stiffness coefficient according to claim 1, characterized in that: The testing process in step 5 is divided into three parts: The first is the idling stage of the machine tool spindle. During this stage, no cutting is done and the exciter is not turned on, so that the machine tool background noise can be recorded through the eddy current displacement sensor. The second stage is when the machine tool spindle is idling and the exciter is turned on. In this stage, the magnitude and phase of the exciting force and the magnitude and phase of the displacement vibration of the workpiece are recorded through the pressure variable force sensor and the eddy current displacement sensor. Finally, the workpiece under test is cut while being excited, and the cutting force signal, vibration signals of the workpiece under test and boring tool, and phase records are recorded.

3. A test system for implementing the method for quickly identifying boring stiffness coefficient according to any one of claims 1-2, characterized in that: It includes an excitation module, a force measurement module, and a displacement measurement module; the excitation module consists of a test computer, a signal generator, a power amplifier, a contact electromagnetic vibrator, and an air-cooling air pump; the test computer is connected to the signal generator via a USB interface, the output end of the signal generator is connected to the input end of the power amplifier via a connecting line, the output end of the power amplifier is connected to the signal input end of the contact electromagnetic vibrator via a connecting line, and the air-cooling air pump is connected to the cooling port of the contact electromagnetic vibrator via a hose; The force measurement module consists of a pressure-variable force sensor, a charge amplifier, a force signal acquisition box, and a test computer. The pressure-variable force sensor is installed between the workbench and the workpiece to be measured. The output end of the pressure-variable force sensor is connected to the input end of the charge amplifier via a connecting line. The output end of the charge amplifier is connected to the input end of the force signal acquisition box via a connecting line. The output end of the force signal acquisition box is connected to the test computer via a USB interface. The displacement measurement module consists of an eddy current displacement sensor, a displacement signal acquisition box, and a second test computer. The three eddy current displacement sensors are installed at the measured point on the workpiece, the front end of the boring tool, and the root of the boring tool, and are connected to the displacement signal acquisition box equipped with an NI acquisition card through connecting cables. The output end of the displacement signal acquisition box is connected to the second test computer through a USB interface.

4. A test system for quickly identifying boring stiffness coefficient according to claim 3, characterized in that: Before the experiment, a 0.5mm thick thin iron sheet with a length of 5mm and a width of 2mm was pasted on the root of the boring tool. Its position on the circumference of the boring tool was consistent with the boring blade. The eddy current displacement sensors located at the measured point at the end of the workpiece and the front end of the boring tool were used to measure the vibration displacement of the measured point at the end of the workpiece and the front end of the boring tool respectively. The eddy current displacement sensor at the root of the boring tool was aligned with the thin iron sheet to record the phase during the rotation of the boring tool.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method for quickly identifying the boring stiffness coefficient according to any one of claims 1 to 2 are implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for quickly identifying the boring stiffness coefficient according to any one of claims 1 to 2 are implemented.

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