CN118143333A - Accurate milling handle of a knife of intelligence based on timely normal position compensation of piezoelectricity drive cutter wearing and tearing high accuracy and state monitoring - Google Patents
Accurate milling handle of a knife of intelligence based on timely normal position compensation of piezoelectricity drive cutter wearing and tearing high accuracy and state monitoring Download PDFInfo
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Abstract
The invention provides an intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of a piezoelectric driven cutter. And a vibration sensor, a force sensor and a displacement sensor are integrated on the basis of the original knife handle. The structure of the head of the cutter handle is changed, the piezoelectric ceramic driver is arranged in the cutter handle, and after receiving voltage, the cutter is pushed to perform micro-displacement compensation, so that the machining precision is improved, and the influence of chips and electromagnetic interference on a circuit can be reduced after the casing is arranged. The wireless sensing fusion intelligent numerical control precise milling cutter handle device can wirelessly measure cutting force, cutting vibration and cutter micro-displacement borne by a rotary cutter, meanwhile, high-precision in-situ compensation is carried out on cutter abrasion, the influence of external factors such as workpiece size and processing complexity is avoided, the structure is simple, the measurement is accurate, the functions are complete, and the influence of sensor arrangement on rigidity and signal attenuation is greatly reduced in structural design.
Description
Technical Field
The invention relates to the technical field of cutting machining, in particular to an intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of a piezoelectric driven cutter.
Background
Cutting is a process that is subject to a combination of factors, in which the tool and workpiece are subjected to a combination of physical quantities such as cutting forces, vibrations, and heat, and in which the wear of the tool also affects the cutting process. The tool state monitoring is a necessary function for realizing intelligent machining, and the intelligent tool monitoring technology can effectively monitor the cutting process, adjust the cutting parameters, reduce the damage of the tool, improve the machining quality and the like, and can effectively ensure the machining precision and the equipment safety.
In the past, it has been common to mount sensors on various components of a processing system, such as a force sensor on a workpiece and a vibration sensor on a machine tool or spindle, and such mounting and testing systems have been costly and inefficient in use. Most of the existing cutting process monitoring tool shanks only monitor single signals such as three-dimensional cutting force, torque, cutting vibration, cutting temperature and the like, and the abrasion of the tool is predicted through single physical quantity. Meanwhile, the research on high-precision in-situ compensation of cutter wear is basically concentrated on a turning tool, and the research on a milling cutter is less.
In the prior art, an intelligent knife handle for monitoring multidimensional cutting force signals exists, the cutting force is measured through a semiconductor silicon strain gauge, the cutting force in the cutting processing process is measured and acquired, and other physical quantities are not measured. The cutting process is a very complex process that cannot be characterized and quantified by a single signal.
In the prior art, an intelligent cutter handle system for measuring cutting force, cutting vibration and cutting temperature in real time exists, the force sensor is used as one of connecting pieces to be installed between the upper flange and the lower flange according to the scheme, meanwhile, the vibration sensor is arranged in a cavity at the tail part of the cutter handle, the thermocouple is arranged in the milling cutter and used for measuring the cutting temperature, and force, vibration and temperature signals in the cutting process can be measured in real time. However, the structure of the commercial cutter handle is greatly changed, so that the rigidity of the cutter handle is greatly influenced, and the cutter handle is difficult to adapt to the processing of difficult-to-cut materials. Meanwhile, the manufacturing cost of the whole cutter handle is high, if the sensor breaks down, the whole cutter handle structure is required to be disassembled for maintenance, so that the time cost is greatly increased, a plurality of fixing blocks are adopted in the information acquisition system structure for fixing the structures such as the lithium battery and the circuit board, the space utilization rate is reduced, the structure is difficult to assemble and disassemble, the function of in-situ compensation of the cutter is not achieved, and the influence of cutter abrasion on machining cannot be compensated.
Therefore, the development of the intelligent precise milling cutter handle based on the high-precision timely in-situ compensation and state monitoring of the abrasion of the piezoelectric driven cutter has great significance.
Disclosure of Invention
The invention aims to provide an intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of a piezoelectric driven cutter, so as to solve the problems in the prior art.
The technical scheme adopted for achieving the purpose of the invention is that the intelligent precise milling cutter handle based on the high-precision timely in-situ compensation and state monitoring of the abrasion of the piezoelectric driving cutter comprises an HSK-A (hollow short cone cutter handle), an end mill, A piezoelectric driving micro-displacement compensation unit and an information acquisition unit.
The HSK-A knife handle comprises A knife handle body and A spring type clamping unit. The cutter handle body sequentially comprises a cutter handle head part, a cutter handle body and a cutter handle tail part from a positioning end to a mounting end. The shank body has an interior cavity. And a through hole II is radially formed in the shank body of the shank. And the through hole II is communicated with the inner cavity of the cutter handle body and the outside. The shaft shoulder at the joint position of the shank body and the shank head is marked as a packaging platform. The shaft shoulder at the joint position of the shank body and the shank tail is marked as a positioning platform. And A protective shell is covered on the periphery of the HSK-A knife handle. The protective housing is hollow casing. The lower extreme of protective housing is shelved on the location platform. The protection shell is used for coating the packaging platform and the handle body of the handle and protecting and sealing the internal module, so that chips and electromagnetic interference can be prevented from affecting the acquisition system. The protective housing, encapsulation platform and handle of a knife handle body enclose out the work chamber of ring cylinder form. The spring type clamping unit comprises a pre-tightening ring, a return spring, a pre-tightening connecting rod and a cutter clamping handle. The tool clamping handle comprises a hollow circular sleeve and a chuck. The inner wall of the lower end of the sleeve is radially protruded to form an installation connecting part. The mounting connection part extends out of the clamping head towards the lower end. The inner cavity of the sleeve is communicated with the inner cavity of the chuck. The inner cavity of the chuck is provided with an internal thread. The cutter clamping handle is arranged at the mounting end of the cutter handle. And a gap exists between the cutter clamping handle and the tail part of the cutter handle. The pre-tightening connecting rod is provided with a through hole I along the axial direction. The upper end of the pre-tightening connecting rod is accommodated in the inner cavity of the cutter handle body, and the lower end of the pre-tightening connecting rod penetrates through the inner cavity of the sleeve and then stretches into the inner cavity of the chuck. The body at the upper end of the pre-tightening connecting rod is sleeved with a pre-tightening ring and a return spring. The return spring is abutted against the pre-tightening ring. The upper end of the end mill is screwed into the inner cavity of the chuck.
The piezoelectric driving micro-displacement compensation unit comprises a lower flexible hinge, a gasket, an upper flexible hinge and a piezoelectric ceramic driver. The upper flexible hinge is disposed at the upper end of the sleeve. The lower flexible hinge is disposed at the lower end of the sleeve. The piezoceramic actuator is disposed in the interior cavity of the sleeve. The upper end and the lower end of the piezoelectric ceramic driver respectively prop against the tail part of the knife handle and the installation connecting part. And a gasket is arranged in a gap between the upper flexible hinge and the tail part of the knife handle. The sleeve is peripherally covered with a drive portion housing for protecting the system. The lower flexible hinge and the upper flexible hinge are housed in the drive section housing. The lower flexible hinge and the upper flexible hinge act as guides in the system so that the system has only micro-displacement compensation in the vertical direction.
The information acquisition unit comprises a piezoelectric film force sensor, an annular circuit board, a lithium battery, a vibration sensor and a displacement sensor. The annular circuit board and the lithium battery are arranged in the working cavity. The annular circuit board is sleeved on the shank body. And the annular circuit board is integrated with an information wireless transmission module, an information acquisition and processing module and a power supply module. The power supply module is electrically connected with the lithium battery. The piezoelectric film force sensor is disposed on an outer wall of the end mill. The vibration sensor is disposed in the interior cavity of the collet. The vibration sensor is clamped between the pre-tightening connecting rod and the end mill, so that the attenuation of vibration signals is reduced, and the accuracy of the signals is ensured. The displacement sensor is arranged in the inner cavity of the cutter handle body. The displacement sensor is positioned above the pre-tightening connecting rod. The piezoelectric film force sensor, the vibration sensor, the displacement sensor and the piezoelectric ceramic driver are all connected with the annular circuit board. The through holes I and II are used for accommodating the sensor wires and the piezoelectric ceramic driver wires. The lithium battery 15 provides continuous and stable voltage for the piezoelectric film force sensor 9, the vibration sensor 26, the displacement sensor 28 and the piezoelectric ceramic driver 29 through the power supply module 31, so that the normal operation of the system is ensured.
When in work, the head of the knife handle is connected with the main shaft of the machine tool. The machine tool spindle drives the end mill to rotate for milling. The piezoelectric ceramic driver generates micron-sized displacement after being subjected to voltage, and the piezoelectric ceramic driver acts on the end mill through the cutter clamping handle to compensate cutter abrasion in situ. After the in-situ compensation process is finished, the end mill is reset through a return spring. The reaction cutting force of the end mill cutting edge for cutting the workpiece is transmitted to the piezoelectric film force sensor, the vibration sensor and the displacement sensor. The vibration sensor monitors cutting vibrations generated by the end mill, the HSK-A shank and the machine tool spindle. The displacement sensor monitors micro-displacement generated by the pre-tightening connecting rod in the cutter abrasion compensation process. Monitoring signals of all the piezoelectric film force sensors, the vibration sensors and the displacement sensors are transmitted to the information acquisition and processing module for processing, and the information wireless transmission module transmits processing results to the upper computer.
Further, a sealing ring is also included. The sealing ring is arranged at the joint position of the protective shell and the positioning platform. The upper surface of the sealing ring is provided with a groove for accommodating a lithium battery. The lithium battery is embedded in the groove. The annular circuit board is connected with the sealing ring through a plurality of single-head copper columns.
Further, three piezoelectric film force sensors are uniformly arranged on the outer wall of the cutter clamping handle. The stability of the measuring system is improved by using more piezoelectric film force sensors than the minimum number of sensors, and the third sensor is used for ensuring that the system has at least two force sensors to work normally on one hand and ensuring the dynamic balance of the rotary cutter bar system on the other hand.
Further, a power switch is arranged on the outer wall of the protective shell. The power switch is connected with the power supply module, and controls the on-off of the lithium battery power supply so as to control the operation and the stop of the intelligent milling cutter handle system.
Further, the information wireless transmission module and the upper computer are in communication through Bluetooth, wiFi, star flash, loRa, zibee, NFC, Z-Wave, NB-IoT, sigfox or 5G connection.
Further, the cutter clamping handle and the driving part shell are made of alloy steel. The gasket is made of stainless steel. The upper flexible hinge and the lower flexible hinge are made of spring steel. The end mill is made of high speed tool steel.
Furthermore, the piezoelectric film force sensor is a PVDF (polyvinylidene fluoride) film force sensor. The displacement sensor is a micro-displacement sensor. The vibration sensor is a PCB (Printed Circuit Board ) vibration sensor.
Further, the driving part shell is connected with the tail part of the knife handle through a driving part shell fixing screw. The annular circuit board is tightly connected with the packaging platform through a plurality of circuit board fixing screws. The shell is tightly connected with the head of the knife handle through a plurality of shell fixing screws. The upper flexible hinge is tightly connected with the gasket through a plurality of gasket fixing screws. The lower flexible hinge is tightly connected with the cutter clamping handle through a plurality of lower flexible hinge fixing screws.
Further, the lithium battery is a rechargeable lithium battery. And a charging socket is arranged on the outer wall of the protective shell. The charging jack is connected with the power supply module. The charging jack 4 is connected with a magnetic charging head. The lithium batteries 15 with different capacities and numbers can be selected according to different working condition requirements, so that the working time of the intelligent milling cutter handle is controlled.
Further, the piezoelectric ceramic actuator employs a PZT-8 (lead zirconate titanate) material as the driving element.
In published paper milling vibration measuring tool handle design and test research, an intelligent tool handle system integrating a vibration sensor and a circuit onto a BT30 tool handle is designed, but the intelligent tool handle system cannot compensate tool wear, meanwhile, cannot measure cutting force signals in the cutting process, the cutting state is jointly influenced by multiple physical quantities, and the cutting process is difficult to characterize by a single physical quantity, so that the invention in the paper has certain limitation.
The technical effects of the invention are undoubted: besides the function of monitoring the cutting state of the cutter, the device can realize high-precision in-situ compensation on the abrasion of the cutter, has the advantages of strong function, strong adaptability, high integration level, stable structure, good rigidity and the like, can effectively improve the detection precision by utilizing the high-precision PVDF piezoelectric film force sensor, the PCB vibration sensor and the micro-displacement sensor, and can effectively improve the machining precision by utilizing the displacement compensation of the piezoelectric ceramic driver. In addition, the application of the device has positive effects on improving the automation and the intelligence of the milling process, and has good economic and social benefits.
Drawings
FIG. 1 is a schematic diagram of an intelligent milling cutter handle device;
FIG. 2 is an exploded view of the entire assembly of the intelligent milling handle assembly;
FIG. 3 is an overall assembled cross-sectional view of the intelligent milling cutter handle assembly;
FIG. 4 is a schematic diagram of an intelligent milling handle drive assembly;
FIG. 5 is a schematic view of the outer appearance of a milling cutter arbor;
FIG. 6 is a cross-sectional view taken along the direction A-A in FIG. 5;
FIG. 7 is a cloud image of a modal analysis of a drive portion of an intelligent milling handle;
FIG. 8 is a cloud image of a harmonic response analysis of a drive portion of an intelligent milling handle;
Fig. 9 is a schematic diagram of an information acquisition system.
In the figure: the tool holder comprises a tool holder head 1, a housing 2, a power switch 3, a charging socket 4, a tool holder tail 5, a driving part housing fixing screw 6, a lower flexible hinge 7, an end mill 8, a PVDF piezoelectric film force sensor 9, a tool clamping handle 10, a lower flexible hinge fixing screw 11, a driving part housing 12, a circuit board 13, an information wireless transmission module 14, a lithium battery 15, a pre-tightening ring 16, a return spring 17, a pre-tightening connecting rod 18, a gasket 19, a gasket fixing screw 20, a sealing ring 21, an upper flexible hinge 22, a housing fixing screw 23, a single-head copper column 24, a circuit board fixing screw 25, a vibration sensor 26, an upper flexible hinge fixing screw 27, a displacement sensor 28, a piezoelectric ceramic driver 29, an information acquisition and processing module 30, a power supply module 31, a through hole I32 and a through hole II 33.
Detailed Description
The present invention is further described below with reference to examples, but it should not be construed that the scope of the above subject matter of the present invention is limited to the following examples. Various substitutions and alterations are made according to the ordinary skill and familiar means of the art without departing from the technical spirit of the invention, and all such substitutions and alterations are intended to be included in the scope of the invention.
Example 1:
The tool is used as a tool terminal in the cutting machining process, and is often used as a main carrier for cutting state monitoring and wear compensation, and the tool handle and the tool have the state monitoring and high-precision in-situ compensation functions through integrating a sensor and a micro-displacement compensation module in the tool. The intelligent milling cutter is characterized in that the sensor, the circuit and the like are integrated on the cutter handle or the milling cutter, so that the cutter handle has a state monitoring function, the cutter can realize self-sensing of the cutting state of the cutter, the monitoring system is prevented from being arranged on a machine tool or a workpiece, the monitoring efficiency is improved, the cost is reduced, and the intelligent milling cutter has higher universality in the actual machining process.
Referring to fig. 1 to 6, the present embodiment provides an intelligent precision milling cutter handle based on high-precision timely in-situ compensation and state monitoring of piezoelectric driving cutter wear, which comprises an HSK-A cutter handle (hollow short cone cutter handle), an end mill 8, A piezoelectric driving micro-displacement compensation unit and an information acquisition unit.
The HSK-A knife handle comprises A knife handle body and A spring type clamping unit. The cutter handle body sequentially comprises a cutter handle head part 1, a cutter handle body and a cutter handle tail part 5 from a positioning end to a mounting end. The shank body has an interior cavity. The shank body is radially provided with a through hole II 33. And the through hole II 33 is communicated with the inner cavity of the cutter handle body and the outside. The shaft shoulder at the joint position of the shank body and the shank head 1 is marked as a packaging platform. The shaft shoulder at the joint position of the shank body and the shank tail 5 is marked as a positioning platform. And A protective shell 2 is arranged on the periphery of the HSK-A knife handle in A covering mode. The protective shell 2 is a hollow shell. The lower end of the protective shell 2 is placed on a positioning platform. The protection shell 2 is used for coating the packaging platform and the handle body of the handle and protecting and sealing the internal module, so that chips and electromagnetic interference can be prevented from affecting the acquisition system. The protection shell 2, the packaging platform and the handle body enclose a circular cylinder-shaped working cavity. The spring type clamping unit comprises a pre-tightening ring 16, a return spring 17, a pre-tightening connecting rod 18 and a cutter clamping handle 10. The tool holder 10 comprises a hollow circular sleeve and a collet. The inner wall of the lower end of the sleeve is radially protruded to form an installation connecting part. The mounting connection part extends out of the clamping head towards the lower end. The inner cavity of the sleeve is communicated with the inner cavity of the chuck. The inner cavity of the chuck is provided with an internal thread. The tool clamping shank 10 is arranged at the shank mounting end. A gap exists between the cutter clamping handle 10 and the tail part 5 of the cutter handle. The pretension connecting rod 18 is provided with a through hole i 32 in the axial direction. The upper end of the pre-tightening connecting rod 18 is accommodated in the inner cavity of the cutter handle body, and the lower end of the pre-tightening connecting rod penetrates through the inner cavity of the sleeve and then stretches into the inner cavity of the chuck. The upper end of the pre-tightening connecting rod 18 is sleeved with a pre-tightening ring 16 and a return spring 17. The return spring 17 abuts the pre-tightening ring 16. The upper end of the end mill 8 is screwed into the interior cavity of the collet.
The piezoelectric driven micro-displacement compensation unit comprises a lower flexible hinge 7, a gasket 19, an upper flexible hinge 22 and a piezoelectric ceramic driver 29. The upper flexible hinge 22 is arranged at the upper end of the sleeve. The lower flexible hinge 7 is arranged at the lower end of the sleeve. The piezoceramic actuator 29 is arranged in the interior of the sleeve. The upper and lower ends of the piezoelectric ceramic driver 29 respectively prop against the tail 5 of the cutter handle and the mounting connection part. A spacer 19 is arranged in a gap between the upper flexible hinge 22 and the shank tail 5. The sleeve is peripherally covered with a drive section housing 12 for protecting the system. The lower flexible hinge 7 and the upper flexible hinge 22 are accommodated in the driving part housing 12. The lower flexible hinge 7 and the upper flexible hinge 22 act as guides in the system so that the system has only micro-displacement compensation in the vertical direction.
The information acquisition unit comprises a piezoelectric film force sensor 9, an annular circuit board 13, a lithium battery 15, a sealing ring 21, a vibration sensor 26 and a displacement sensor 28. The annular circuit board 13 and the lithium battery 15 are arranged in the working chamber. The annular circuit board 13 is sleeved on the shank body. The annular circuit board 13 is integrated with an information wireless transmission module 14, an information acquisition and processing module 30 and a power supply module 31. The power supply module 31 is electrically connected to the lithium battery 15. The sealing ring 21 is arranged at the joint position of the protective shell 2 and the positioning platform. The upper surface of the sealing ring 21 is provided with a groove for accommodating the lithium battery 15. The lithium battery 15 is embedded in the groove. The annular circuit board 13 is connected with the sealing ring 21 through a plurality of single-head copper columns 24. The piezoelectric film force sensor 9 is arranged on the outer wall of the end mill 8. The vibration sensor 26 is disposed in the interior cavity of the collet. The vibration sensor 26 is clamped between the pre-tightening connecting rod 18 and the end mill 8, so that the attenuation of vibration signals is reduced, and the accuracy of the signals is ensured. The displacement sensor 28 is disposed in the shank body cavity. The displacement sensor 28 is located above the pretensioned linkage 18. The piezoelectric film force sensor 9, the vibration sensor 26, the displacement sensor 28 and the piezoelectric ceramic driver 29 are all connected with the annular circuit board 13. The through holes I32 and II 33 are used for accommodating the sensor wires and the piezoelectric ceramic driver wires. The lithium battery 15 provides continuous and stable voltage for the piezoelectric film force sensor 9, the vibration sensor 26, the displacement sensor 28 and the piezoelectric ceramic driver 29 through the power supply module 31, so that the normal operation of the system is ensured.
When in operation, the tool shank head 1 is connected with a main shaft of a machine tool. The machine tool spindle drives the end mill 8 to rotate for milling. The piezo-ceramic actuator 29 is displaced in the micrometer range upon application of a voltage, and is applied to the end mill 8 via the tool holder 10 to compensate for tool wear in situ. After the in-situ compensation process is completed, the end mill 8 is reset by the return spring 17. Referring to fig. 9, the reaction cutting force of the end mill 8 cutting the workpiece is transmitted to the piezoelectric film force sensor 9, the vibration sensor 26, and the displacement sensor 28. The vibration sensor 26 monitors cutting vibrations generated by the end mill 8, the HSK-A shank and the machine spindle. The cutter-handle-spindle system generates cutting vibration under the combined action of self-excited vibration and forced vibration, so that the cutting vibration acts on the vibration sensor 26 above the end mill, and charge signals generated by the vibration sensor 26 are converted into voltage signals through the information acquisition and processing module 22 and are transmitted to an upper computer. The displacement sensor 28 monitors the micro-displacement of the pretensioned linkage 18 during tool wear compensation. The monitoring signals of all the piezoelectric film force sensors 9, the vibration sensors 26 and the displacement sensors 28 are transmitted to the information acquisition and processing module 30 for processing, and the information wireless transmission module 14 transmits the processing results to the upper computer.
According to the embodiment, the force sensor, the vibration acceleration sensor and the displacement sensor are integrated on the cutter handle and the cutter system, so that cutting force, cutting vibration and micro-displacement physical signals in the cutting process can be measured more accurately and conveniently, and meanwhile, high-precision in-situ compensation is carried out on cutter abrasion by utilizing the piezoelectric ceramic driving module based on the micro-displacement sensor. The embodiment has the advantages of high integration level, strong adaptability, complete functions, simple structure and good rigidity, can accurately measure the cutting force and the cutting vibration in the cutting process in real time, and simultaneously realizes high-precision in-situ compensation on the cutter based on the displacement sensor.
The vibration sensor, the force sensor and the displacement sensor are integrated on the basis of the original cutter handle, the defects that the traditional rotary intelligent cutter handle is single in monitoring signal and cannot comprehensively represent cutting process information and state and the like are overcome, the requirements of real-time wireless monitoring of three-dimensional cutting force and three-dimensional cutting vibration of a cutter in complex processing environments such as high-speed milling are met, meanwhile, the head structure of the cutter handle is changed, a piezoelectric ceramic driver is installed in the cutter handle, after voltage is received, a milling cutter is pushed to conduct micro-displacement compensation, machining precision is improved, and the influence of cutting chips and electromagnetic interference on a circuit can be reduced after a shell is installed. The wireless sensing fusion intelligent numerical control precise milling cutter handle device can wirelessly measure cutting force, cutting vibration and cutter micro-displacement borne by a rotary cutter, meanwhile, high-precision in-situ compensation is carried out on cutter abrasion, the influence of external factors such as workpiece size and processing complexity is avoided, the structure is simple, the measurement is accurate, the functions are complete, and the influence of sensor arrangement on rigidity and signal attenuation is greatly reduced in structural design.
In summary, the invention designs a device for measuring cutting force and cutting vibration in the cutting process while realizing high-precision in-situ compensation on cutter abrasion, and creatively realizes in-situ compensation and reset functions of the cutter by designing structures such as a pre-tightening ring, a restoring connecting rod, a pre-tightening connecting rod, a flexible hinge and the like. The monitoring device is suitable for monitoring links of cutting force and cutting vibration in difficult-to-process materials and complex processing environments, and improves automation and intellectualization of the cutting processing process.
Example 2:
The main content of this embodiment is the same as embodiment 1, wherein three piezoelectric film force sensors 9 are uniformly arranged on the outer wall of the tool holding handle 10. The stability of the measuring system is improved by using more piezoelectric film force sensors than the least sensors by 2, and the third sensor is used for ensuring that the system has at least two force sensors to work normally on one hand and ensuring the dynamic balance of the rotary cutter bar system on the other hand. The three piezoelectric film force sensors 9 are spaced apart by an angle as shown in fig. 5. The device can be used for measuring cutting force in the X direction and the Y direction and torque in the Z direction; the sensor wire is connected with the information acquisition system through a semicircular groove under the sealing ring.
Two of the force sensors are used for measuring feeding force, transverse force and torque in the Z direction in the cutting process, and the other force sensor is used for balancing the cutting force measuring system. The cutting force measuring structure is close to the processing area, so that signal measurement is more accurate; the main structure of the cutter or the cutter handle is not required to be changed, so that the rigidity of the system is ensured, and the installation and the maintenance are convenient.
The end mill 8 can be regarded as a cantilever beam clamped on a cutter handle, and the Euler-Bernoulli beam theory is adopted to analyze the end mill 8, the bending strain generated by the PVDF position can be obtained through a bending formula, so that the relation between the cutting force and the strain is established:
Where H yi and H xi represent the horizontal and vertical distances of the i-th sheet strain gauge center point from the mill center point, F y and F x represent the forces experienced by the end mill 8 in the x and y directions, E t represents the modulus of elasticity of the end mill 8, and D 0 represents the diameter of the end mill 8, respectively.
The lateral strain caused by the poisson effect is:
εix＝-vtεia(i＝1,2,3) (2)
From the above equation, it can be seen that the axial normal strain caused by the axial force F Z is typically 1-2 orders of magnitude lower than the bending strain obtained from equation (1). For this purpose, consider the ratio of the bending strain ε x induced by the feed force F x to the axial strain ε z induced by F Z as:
Considering that the magnitudes of the axial and normal forces during end milling are typically less than the bending stresses, the strain in the axial normal is not considered in the rest of the model development. As the rotation of the tools H yi and H xi is changed, it can be obtained by formulas (4) and (5).
Wherein θ 1＝0°,θ2＝120°,θ3 =240°, in combination with (1), (4) and (5), the bending strain of the PVDF force sensor at the i-th position is:
Wherein θ can be given by:
θ＝ω0t+φ0 (7)
Where ω 0 and φ 0 are the initial angular velocity of the end mill and the initial angular position of the PVDF force sensor, respectively.
Example 3:
The main content of this embodiment is the same as embodiment 1 or 2, wherein a power switch 3 is disposed on the outer wall of the protective housing 2. The power switch 3 is connected with the power supply module 31, and the power switch 3 controls the on-off of the power supply of the lithium battery 15 so as to control the operation and the stop of the intelligent milling cutter handle system.
Example 4:
The main content of this embodiment is the same as any one of embodiments 1 to 3, wherein the information wireless transmission module 14 and the upper computer implement communication through a bluetooth, wiFi, star flash, loRa, zibee, NFC, Z-Wave, NB-IoT, sigfox or 5G connection mode.
Example 5:
The main content of this embodiment is the same as embodiment 4, wherein the upper computer is turned on to search for WIFI according to the preset IP address and port number and connected, the wireless transmission module 14 establishes connection with the upper computer, and the preparation is finished.
Example 6:
this embodiment is mainly the same as any one of embodiments 1 to 4, wherein the tool holding shank 10 and the driving portion housing 12 are made of alloy steel. The gasket 19 is made of stainless steel. The upper flexible hinge 22 and the lower flexible hinge 7 are made of spring steel. The end mill 8 is made of high speed tool steel.
Example 7:
the main content of this embodiment is the same as any one of embodiments 1 to 6, wherein the piezoelectric film force sensor 9 is a PVDF (polyvinylidene fluoride) film force sensor. The displacement sensor 28 is a micro displacement sensor. The vibration sensor 26 is a PCB (Printed Circuit Board ) vibration sensor.
Example 8:
this embodiment is basically the same as any one of embodiments 1 to 7, wherein the driving part housing 12 is connected to the shank portion 5 by a driving part housing fixing screw 6. The annular circuit board 13 is tightly connected with the packaging platform through a plurality of circuit board fixing screws 25. The shell 2 is tightly connected with the head part 1 of the knife handle through a plurality of shell fixing screws 23. The upper flexible hinge 22 and the spacer 19 are tightly connected by a plurality of spacer fixing screws 20. The lower flexible hinge 7 is tightly connected with the cutter clamping handle 10 through a plurality of lower flexible hinge fixing screws 11.
Example 9:
The main content of this embodiment is the same as any one of embodiments 1 to 8, wherein the lithium battery 15 is a rechargeable lithium battery. And a charging socket 4 is arranged on the outer wall of the protective shell 2. The charging jack 4 is connected to a power supply module 31. The charging jack 4 is connected with a magnetic charging head. The lithium batteries 15 with different capacities and numbers can be selected according to different working condition requirements, so that the working time of the intelligent milling cutter handle is controlled.
Example 10:
This embodiment is mainly the same as any one of embodiments 1 to 9, wherein the piezoelectric ceramic actuator 29 uses PZT-8 (lead zirconate titanate) material as the driving element. As the most critical piezoelectric ceramic material in the piezoelectric ceramic actuator 29, lead zirconate titanate (PZT-8) material having a high electromechanical coupling coefficient and a small dielectric loss is selected in the present embodiment, and the material properties thereof are shown in Table 1.
TABLE 1
Example 11:
The main content of this embodiment is the same as any one of embodiments 1 to 10, wherein, referring to fig. 7 and 8, for a model of theoretical design, the model harmonic response analysis is performed on the most important driving part in the structure by adopting ansys simulation software. The materials in the structure are first defined separately in the ansys simulation software. The self-adaptive gridding is carried out on the piezoelectric ceramic by adopting the size of a 3mm cell, 74636 nodes and 37005 cells are finally obtained, the free mode solving is finally carried out on the structure, as shown in fig. 7, the first-order mode frequency of the driving part is 1144.8Hz, and then the harmonic response analysis result of the driving part shown in fig. 8 is combined, piezoelectric characteristics are endowed to the piezoelectric ceramic by utilizing a plug-in piezo and mes plug-in the ansys simulation software, 300V voltage is applied to the upper surface of the piezoelectric ceramic, 0V voltage is applied to the lower surface of the piezoelectric ceramic to form a harmonic response boundary condition, the resonant frequency of the piezoelectric ceramic is 1154Hz, the modal frequency of the piezoelectric ceramic is close to the mode frequency of the driving part, and the theoretical design of the piezoelectric ceramic is basically correct.
Claims (10)
1. Accurate milling handle of a knife of intelligence based on accurate in situ compensation of piezoelectricity drive cutter wearing and tearing high accuracy and state monitoring, its characterized in that: the device comprises an HSK-A knife handle, an end mill (8), A piezoelectric driving micro-displacement compensation unit and an information acquisition unit;
The HSK-A knife handle comprises A knife handle body and A spring type clamping unit; the cutter handle body sequentially comprises a cutter handle head (1), a cutter handle body and a cutter handle tail (5) from a positioning end to a mounting end; the cutter handle body is provided with an inner cavity; a through hole II (33) is radially formed in the shank body of the shank; the through hole II (33) is communicated with the inner cavity of the cutter handle body and the outside; the shaft shoulder at the joint position of the shank body and the shank head (1) is marked as a packaging platform; the shaft shoulder at the joint position of the shank body and the shank tail (5) is marked as a positioning platform; a protective shell (2) is arranged on the periphery of the HSK-A knife handle in A covering mode; the protective shell (2) is a hollow shell; the lower end of the protective shell (2) is placed on the positioning platform; the packaging platform and the handle body are coated by the protective shell (2); the protective shell (2), the packaging platform and the handle body are surrounded to form a circular cylinder-shaped working cavity; the spring type clamping unit comprises a pre-tightening ring (16), a return spring (17), a pre-tightening connecting rod (18) and a cutter clamping handle (10); the tool clamping handle (10) comprises a hollow circular sleeve and a chuck; the inner wall of the lower end of the sleeve is radially protruded to form an installation connecting part; the mounting connection part extends out of the chuck towards the lower end; the inner cavity of the sleeve is communicated with the inner cavity of the chuck; an inner cavity of the chuck is provided with an inner thread; the cutter clamping handle (10) is arranged at the mounting end of the cutter handle; a gap exists between the cutter clamping handle (10) and the tail part (5) of the cutter handle; the pre-tightening connecting rod (18) is provided with a through hole I (32) along the axial direction; the upper end of the pre-tightening connecting rod (18) is accommodated in the inner cavity of the cutter handle body, and the lower end of the pre-tightening connecting rod penetrates through the inner cavity of the sleeve and then stretches into the inner cavity of the chuck; a pre-tightening ring (16) and a return spring (17) are sleeved on the rod body at the upper end of the pre-tightening connecting rod (18); the return spring (17) is abutted against the pre-tightening ring (16); the upper end of the end mill (8) is screwed into the inner cavity of the chuck;
The piezoelectric driving micro-displacement compensation unit comprises a lower flexible hinge (7), a gasket (19), an upper flexible hinge (22) and a piezoelectric ceramic driver (29); the upper flexible hinge (22) is arranged at the upper end of the sleeve; the lower flexible hinge (7) is arranged at the lower end of the sleeve; the piezoceramic actuator (29) is arranged in the inner cavity of the sleeve; the upper end and the lower end of the piezoelectric ceramic driver (29) respectively prop against the tail part (5) of the cutter handle and the installation connecting part; a gasket (19) is arranged in a gap between the upper flexible hinge (22) and the tail part (5) of the cutter handle; the sleeve periphery is covered with a driving part shell (12); the lower flexible hinge (7) and the upper flexible hinge (22) are accommodated in the driving part housing (12);
The information acquisition unit comprises a piezoelectric film force sensor (9), an annular circuit board (13), a lithium battery (15), a vibration sensor (26) and a displacement sensor (28); the annular circuit board (13) and the lithium battery (15) are arranged in the working cavity; the annular circuit board (13) is sleeved on the shank body; the annular circuit board (13) is integrated with an information wireless transmission module (14), an information acquisition and processing module (30) and a power supply module (31); the power supply module (31) is electrically connected with the lithium battery (15); the piezoelectric film force sensor (9) is arranged on the outer wall of the end mill (8); the vibration sensor (26) is arranged in the inner cavity of the chuck; the vibration sensor (26) is clamped between the pre-tightening connecting rod (18) and the end mill (8); the displacement sensor (28) is arranged in the inner cavity of the cutter handle body; the displacement sensor (28) is positioned above the pre-tightening connecting rod (18); the piezoelectric film force sensor (9), the vibration sensor (26), the displacement sensor (28) and the piezoelectric ceramic driver (29) are all connected with the annular circuit board (13); the through holes I (32) and the through holes II (33) are used for accommodating the sensor wires and the piezoelectric ceramic driver wires;
When in work, the cutter handle head (1) is connected with a main shaft of a machine tool; the machine tool spindle drives the end milling cutter (8) to rotate for milling; the piezoelectric ceramic driver (29) generates displacement after being subjected to voltage, and the piezoelectric ceramic driver acts on the end mill (8) through the cutter clamping handle (10) to compensate the cutter abrasion in situ; after the in-situ compensation process is finished, resetting the end mill (8) through a return spring (17); the reaction cutting force of the cutting workpiece on the edge of the end mill (8) is transmitted to a piezoelectric film force sensor (9), a vibration sensor (26) and a displacement sensor (28); the vibration sensor (26) monitors cutting vibration generated by the end mill (8), the HSK-A cutter handle and the machine tool spindle; a displacement sensor (28) monitors micro-displacement generated by the pre-tightening connecting rod (18) in the process of compensating cutter abrasion; monitoring signals of all the piezoelectric film force sensors (9), the vibration sensors (26) and the displacement sensors (28) are transmitted to the information acquisition and processing module (30) for processing, and the information wireless transmission module (14) transmits processing results to the upper computer.
2. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: also comprises a sealing ring (21); the sealing ring (21) is arranged at the joint position of the protective shell (2) and the positioning platform; the upper surface of the sealing ring (21) is provided with a groove for accommodating the lithium battery (15); the lithium battery (15) is embedded in the groove; the annular circuit board (13) is connected with the sealing ring (21) through a plurality of single-head copper columns (24).
3. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: three piezoelectric film force sensors (9) are uniformly arranged on the outer wall of the cutter clamping handle (10).
4. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: a power switch (3) is arranged on the outer wall of the protective shell (2); the power switch (3) is connected with the power supply module (31), and the power switch (3) controls the on-off of the power supply of the lithium battery (15) so as to control the operation and the stop of the intelligent milling cutter handle system.
5. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: and the information wireless transmission module (14) is communicated with the upper computer through Bluetooth, wiFi, star flash, loRa, zibee, NFC, Z-Wave, NB-IoT, sigfox or 5G connection modes.
6. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: the cutter clamping handle (10) and the driving part shell (12) are made of alloy steel; the gasket (19) is made of stainless steel; the upper flexible hinge (22) and the lower flexible hinge (7) are made of spring steel; the end mill (8) is made of high-speed tool steel.
7. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: the piezoelectric film force sensor (9) is a PVDF film force sensor; the displacement sensor (28) is a micro displacement sensor; the vibration sensor (26) is a PCB vibration sensor.
8. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: the driving part shell (12) is connected with the tail part (5) of the cutter handle through a driving part shell fixing screw (6); the annular circuit board (13) is tightly connected with the packaging platform through a plurality of circuit board fixing screws (25); the shell (2) is tightly connected with the head (1) of the knife handle through a plurality of shell fixing screws (23); the upper flexible hinge (22) is tightly connected with the gasket (19) through a plurality of gasket fixing screws (20); the lower flexible hinge (7) is tightly connected with the cutter clamping handle (10) through a plurality of lower flexible hinge fixing screws (11).
9. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: the lithium battery (15) is a rechargeable lithium battery; a charging jack (4) is arranged on the outer wall of the protective shell (2); the charging jack (4) is connected with the power supply module (31).
10. The intelligent precise milling cutter handle based on high-precision timely in-situ compensation and state monitoring of wear of piezoelectric driven cutters according to claim 1, wherein the intelligent precise milling cutter handle is characterized in that: the piezoelectric ceramic actuator (29) uses PZT-8 material as the driving element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311688633.1A CN118143333A (en) | 2023-12-08 | 2023-12-08 | Accurate milling handle of a knife of intelligence based on timely normal position compensation of piezoelectricity drive cutter wearing and tearing high accuracy and state monitoring |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311688633.1A CN118143333A (en) | 2023-12-08 | 2023-12-08 | Accurate milling handle of a knife of intelligence based on timely normal position compensation of piezoelectricity drive cutter wearing and tearing high accuracy and state monitoring |
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| Publication Number | Publication Date |
|---|---|
| CN118143333A true CN118143333A (en) | 2024-06-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311688633.1A Pending CN118143333A (en) | 2023-12-08 | 2023-12-08 | Accurate milling handle of a knife of intelligence based on timely normal position compensation of piezoelectricity drive cutter wearing and tearing high accuracy and state monitoring |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118143333A (en) |
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2023
- 2023-12-08 CN CN202311688633.1A patent/CN118143333A/en active Pending
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