Longitudinal-torsional combined robust ultrasonic cutter handle for large-diameter cutter and design method of longitudinal-torsional combined robust ultrasonic cutter handle

Abstract

The invention relates to a longitudinal-torsion combined robust ultrasonic cutter handle for a large-diameter cutter and a design method of the longitudinal-torsion combined robust ultrasonic cutter handle. The ultrasonic scalpel comprises a scalpel handle and a transducer arranged in the scalpel handle. The transducer comprises an amplitude-change pole, a piezoelectric ceramic piece, a positive electrode, a negative electrode and a rear cover; the piezoelectric ceramic pieces are arranged between the rear end of the amplitude-change pole and the rear cover in the axial direction in a stacked mode. The negative electrodes and the positive electrodes are clamped between every two adjacent piezoelectric ceramic pieces in a staggered mode, between the rear end of the amplitude-change pole and the piezoelectric ceramic pieces and between the rear cover and the piezoelectric ceramic pieces. The rear cover is used for providing inertial mass; the amplitude-change pole is of a double-taper structure which contracts firstly and then releases, and a transition section is formed between the two tapers. A spiral groove is formed in the axial direction of the amplitude-change pole; the knife handle is provided with a contact conductive contact, the contact conductive contact and the knife handle are arranged in an electric insulation mode, and the contact conductive contact is electrically connected with the positive electrode and the negative electrode through wires. The tool can have the vibration modes of longitudinal vibration and torsional vibration at the same time, and the machining effect and efficiency are improved.

Description

A robust ultrasonic tool holder with longitudinal-torsion coupling for large-diameter cutting tools and its design method. Technical Field

[0001] This invention relates to the field of ultrasonic machining technology, and in particular to a longitudinal-torsion combined robust ultrasonic tool holder for large-diameter cutting tools and its design method. Background Technology

[0002] Ultrasonic machining technology offers numerous advantages, including reduced cutting forces, improved machining accuracy, and applicability to hard and brittle materials. During the machining process, ultrasonic machining does not alter the physical properties of the metal, allowing for higher precision and accuracy at a relatively low cost, making it an important processing method in modern manufacturing. Compared to one-dimensional longitudinal ultrasonic vibration, longitudinal-torsional combined ultrasonic vibration machining provides a spiral grinding composite effect, significantly reducing cutting forces, minimizing tool wear, and further lowering cutting temperatures, making it more suitable for machining heat-sensitive materials.

[0003] However, since milling cutters or grinding rods with relatively small diameters are usually used during machining, existing ultrasonic tool holders are often designed using such tools, resulting in poor tool compatibility. For example, patent CN112934650A describes a large-amplitude longitudinal-torsional composite ultrasonic vibration amplitude transformer. When using conventional tools, it has good versatility and large amplitude, but when using large-diameter grinding discs or face milling cutters, due to changes in the mode or excessive tool load, the ultrasonic vibration is often weak and cannot reach the expected amplitude. Summary of the Invention

[0004] Therefore, this invention provides a robust ultrasonic tool holder with longitudinal and torsional vibration for large-diameter cutting tools and its design method. It can be compatible with large-sized cutting tools with a certain diameter and mass range. It not only allows the tool to have both longitudinal and torsional vibration modes at the same time, improving the machining effect and efficiency, but also maintains stable vibration characteristics under complex working conditions, ensuring consistent machining results.

[0005] To address the aforementioned technical problems, this invention provides a robust ultrasonic tool holder with longitudinal-torsion coupling for large-diameter cutting tools, comprising a tool holder and a transducer disposed within the tool holder; the transducer includes an amplitude transformer, piezoelectric ceramic plates, a positive electrode, a negative electrode, and a rear cover; a plurality of piezoelectric ceramic plates are stacked axially between the rear end of the amplitude transformer and the rear cover; the negative electrode and the positive electrode are respectively alternately sandwiched between two adjacent piezoelectric ceramic plates, and between the rear end of the amplitude transformer and the piezoelectric ceramic plates, and between the rear cover and the piezoelectric ceramic plates; the rear cover is used to provide inertial mass to direct energy to the amplitude transformer. Directional radiation; the amplitude transformer has a double-tapered structure that retracts and then expands, with a transition section between the two tapers; the front end of the amplitude transformer has a tool end for mounting a cutting tool; a helical groove is provided along the axial direction of the amplitude transformer, which is used to convert part of the longitudinal vibration of the amplitude transformer into torsional vibration to form a combined longitudinal-torsional vibration; the tool holder is provided with conductive contacts that are electrically insulated from the tool holder, and the conductive contacts are electrically connected to the positive electrode and the negative electrode respectively through wires; the conductive contacts are used to supply power to the transducer through contact with the machine tool spindle.

[0006] In one embodiment of the present invention, the amplitude transformer is hollowed out at the center of the portion where it transitions from the cutter end to the double-tapered structure, in order to increase the magnification of the amplitude transformer.

[0007] In one embodiment of the present invention, four piezoelectric ceramic sheets are provided.

[0008] In one embodiment of the invention, the cutter tip is tapered in a direction away from the front end of the amplitude transformer.

[0009] In one embodiment of the present invention, the thickness of the rear cover is used for adjusting the resonant frequency, the position where the ceramic plate intersects with the amplitude transformer is selected as the nodal surface, and the sum of the thicknesses of the ceramic plate and the rear cover is set as... Wavelength, amplitude rod is Wavelength, i.e.: ;in: This refers to the length of the back cover. The thickness of the ceramic sheet; For the back cover wave velocity; For ceramic plate wave velocity; The target operating frequency of the ultrasonic tool holder; ceramic sheet thickness. ceramic plate wave velocity Based on the material chosen for the back cover, the back cover wave velocity was determined. Substituting into the formula, we obtain the length of the back cover. .

[0010] In one embodiment of the present invention, the length of the amplitude transformer is... Wavelength, according to the formula: ;in, This refers to the length of the amplitude transformer. The wave velocity of the amplitude transformer is determined by looking up the wave velocity of the amplitude transformer based on the material selected for the amplitude transformer. Substituting into the formula, we obtain the length of the amplitude transformer. .

[0011] In one embodiment of the present invention, the longitudinal magnification factor of the amplitude transformer is... Represented as: ;in, , is the longitudinal magnification factor without the spiral groove, and is the ratio of the contact area between the rear end of the amplitude transformer and the piezoelectric ceramic plate to the area of ​​the cutting edge of the amplitude transformer. This is the attenuation factor of the spiral groove on the longitudinal magnification. ; To mitigate the nonlinear relationship between the effect and the number of slots, ; This is the sensitivity index of longitudinal amplitude to helix angle. ; The sensitivity of the longitudinal magnification factor to deviations of the slot length from the optimal value is considered for materials commonly used in amplitude transformers. ; To find the optimal length of the spiral groove, , The length of the amplitude transformer; the torsional amplification factor of the amplitude transformer. Represented as: Among them, M t0 is the torsional amplification factor without the spiral groove, and is the square of the ratio of the contact area between the rear end of the amplitude transformer and the piezoelectric ceramic sheet to the area of ​​the cutting edge of the amplitude transformer; To reverse the saturation rate of the amplification factor as the number of slots increases, ; For the nonlinear exponent of the saturation process, ; The strength index for the increase in torsional amplitude, ; This is the scaling correction factor for the helix angle. .

[0012] In one embodiment of the present invention, for the two tapers in the double-tapered structure of the amplitude transformer... , , is represented as: ; ; ;in, The diameter at which the rear end of the amplitude transformer contacts the end of the piezoelectric ceramic plate; The diameter of the transition section between the two tapers in the double-tapered structure of the amplitude transformer; The diameter of the cutter tip of the amplitude transformer; The length from the end of the amplitude transformer bar that contacts the ceramic plate to the end of the first taper. The length of the transition section between the two tapers in the double-tapered structure of the amplitude transformer; The length of the amplitude transformer transition to the cutter tip is calculated based on the desired magnification. and The ratio of these values ​​also has the maximum stress: ;in, The Young's modulus of the material selected for the amplitude transformer. The target operating frequency of the ultrasonic tool holder. Wave velocity of the material selected for the amplitude transformer bar For the maximum input amplitude, This is the amplification factor of the amplitude transformer; where the maximum stress is less than two-thirds of the allowable stress of the material.

[0013] In one embodiment of the present invention, the diameter of the rear end of the amplitude transformer contacting the end of the piezoelectric ceramic plate is... The diameter of the transition section between the two tapers of the amplitude rod's double-tapered structure. Inner diameter of the amplitude transformer cutter end The inner diameter of the transition section between the two tapers of the amplitude rod's double-tapered structure. ; diameter of the cutter end of the amplitude transformer The length from the end of the amplitude transformer bar that contacts the ceramic plate to the end of the first taper. The length of the transition section between the two tapers in the double-tapered structure of the amplitude transformer. ; Length of the amplitude transformer transition to the cutter tip Number of spiral grooves ; length of the spiral groove ; Angle of the spiral groove .

[0014] The present invention also provides a design method for a longitudinally torsion-bonded robust ultrasonic tool holder for large-diameter cutting tools, comprising: (1) determining the length of the transducer back cover; selecting the position at the junction of the ceramic plate and the amplitude transformer as the nodal surface, and setting the sum of the thicknesses of the ceramic plate and the back cover as... Wavelength, amplitude rod is Wavelength, i.e.: ;in: This refers to the length of the back cover. The thickness of the ceramic sheet; For the back cover wave velocity; For ceramic plate wave velocity; The target operating frequency of the ultrasonic tool holder; the length of the amplitude transformer is... Wavelength, according to the formula: ;in, This refers to the length of the amplitude transformer. For the amplitude transformer wave velocity; The target operating frequency of the ultrasonic tool holder; ceramic sheet thickness. ceramic plate wave velocity Based on the material chosen for the back cover, the back cover wave velocity was determined. Substituting into the formula, we obtain the length of the back cover. (2) Determine the length of the amplitude transformer; the length of the amplitude transformer is Wavelength, according to the formula: ;in, This refers to the length of the amplitude transformer. The wave velocity of the amplitude transformer is determined by looking up the wave velocity of the amplitude transformer based on the material selected for the amplitude transformer. Substituting into the formula, we obtain the length of the amplitude transformer. (3) Determine the longitudinal magnification factor of the amplitude transformer. and torsional magnification The longitudinal magnification factor of the amplitude transformer. Represented as: ;in, , is the longitudinal magnification factor without the spiral groove, and is the ratio of the contact area between the rear end of the amplitude transformer and the piezoelectric ceramic plate to the area of ​​the cutting edge of the amplitude transformer. This is the attenuation factor of the spiral groove on the longitudinal magnification. ; To mitigate the nonlinear relationship between the effect and the number of slots, ; This is the sensitivity index of longitudinal amplitude to helix angle. ; The sensitivity of the longitudinal magnification factor to deviations of the slot length from the optimal value is considered for materials commonly used in amplitude transformers. ; To find the optimal length of the spiral groove, , The length of the amplitude transformer; the torsional amplification factor of the amplitude transformer. Represented as: Among them, M t0 is the torsional amplification factor without the spiral groove, and is the square of the ratio of the contact area between the rear end of the amplitude transformer and the piezoelectric ceramic sheet to the area of ​​the cutting edge of the amplitude transformer; To reverse the saturation rate of the amplification factor as the number of slots increases, ; For the nonlinear exponent of the saturation process, ; The strength index for the increase in torsional amplitude, ; This is the scaling correction factor for the helix angle. (4) Determine the structural parameters of the double-tapered boom; For the two tapers in the double-tapered boom structure , , is represented as: ; ; ;in, The diameter at which the rear end of the amplitude transformer contacts the end of the piezoelectric ceramic plate; The diameter of the transition section between the two tapers in the double-tapered structure of the amplitude transformer; The diameter of the cutter tip of the amplitude transformer; The length from the end of the amplitude transformer bar that contacts the ceramic plate to the end of the first taper. The length of the transition section between the two tapers in the double-tapered structure of the amplitude transformer; The length of the amplitude transformer transition to the cutter tip is calculated based on the desired magnification. and The ratio of these values ​​also has the maximum stress: ;in, The Young's modulus of the material selected for the amplitude transformer. The target operating frequency of the ultrasonic tool holder. Wave velocity of the material selected for the amplitude transformer bar For the maximum input amplitude, This is the amplification factor of the amplitude transformer; where the maximum stress is less than two-thirds of the allowable stress of the material.

[0015] Compared with the prior art, the above-mentioned technical solution of the present invention has the following advantages: The longitudinal-torsional combined robust ultrasonic tool holder and its design method for large-diameter cutting tools described in the present invention enable the tool to simultaneously possess longitudinal and torsional vibration modes, improving machining effect and efficiency. Moreover, through structural optimization and parameter synergistic design, the system possesses outstanding robustness, maintaining stable vibration characteristics even under complex working conditions such as changes in tool size, fluctuations in machining load, and long-term continuous operation. Compared with conventional ultrasonic tool holders, the present invention has better tool compatibility and can be adapted to heavy-duty tools such as large-diameter grinding discs and face milling cutters. Attached Figure Description

[0016] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] Figure 1 is a structural schematic diagram of the longitudinal torsion-bonded robust ultrasonic tool holder of the present invention for large-diameter cutting tools.

[0018] Figure 2 is a schematic diagram of the structure of the amplitude transformer of the present invention.

[0019] Explanation of the markings on the attached diagrams: 1. Tool holder; 2. Amplitude rod; 21. Double taper structure; 22. Transition section; 23. Spiral groove; 3. Piezoelectric ceramic; 4. Positive electrode; 5. Negative electrode; 6. Back cover; 7. Contact conductive point. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0021] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0022] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0023] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0024] Example 1 Referring to Figure 1, this embodiment provides a longitudinally torsionally robust ultrasonic tool holder 1 for large-diameter cutting tools, including a tool holder 1 and a transducer disposed within the tool holder 1. The transducer includes an amplitude transformer 2, piezoelectric ceramic plates 3, a positive electrode 4, a negative electrode 5, and a rear cover 6. Multiple piezoelectric ceramic plates 3 are stacked axially between the rear end of the amplitude transformer 2 and the rear cover 6. The negative electrode 5 and the positive electrode 4 are respectively staggered between adjacent piezoelectric ceramic plates 3, and between the rear end of the amplitude transformer 2 and the piezoelectric ceramic plates 3, and between the rear cover 6 and the piezoelectric ceramic plates 3. The rear cover 6 provides inertial mass to direct energy towards the amplitude transformer 2. The amplitude transformer 2 is a double-tapered structure 21 that retracts and then expands, with a transition section 22 formed between the two tapers. The front end of the amplitude transformer 2 is provided with a tool end for mounting a cutting tool. A spiral groove 23 is provided along the axial direction of the amplitude transformer 2. The spiral groove 23 is used to convert part of the longitudinal vibration of the amplitude transformer 2 into torsional vibration to form a combined longitudinal and torsional vibration. The tool holder 1 is provided with a contact conductive contact 7, which is electrically insulated from the tool holder 1. The contact conductive contact 7 is electrically connected to the positive electrode 4 and the negative electrode 5 respectively through wires. The contact conductive contact 7 is used to supply power to the transducer through contact with the machine tool spindle.

[0025] Furthermore, referring to Figure 2, the amplitude transformer 2 has a double-tapered structure that first retracts and then expands. The tool is mounted at the front end of the tapered section, which is suitable for large-diameter tools. By designing the taper, length, and slotted structure of the two tapered structures at the front and rear of the amplitude transformer 2, the vibration of the tip carrying the tool is adjusted.

[0026] Furthermore, the helical grooves 23 on the amplitude transformer 2 convert part of the longitudinal vibration into torsional vibration, achieving a combined longitudinal and torsional vibration. The magnification of the tool tip is related to the number of helical grooves 23 on the amplitude transformer 2. Length of spiral groove 23 Angle of spiral groove 23 There is a certain relationship between the number of spiral grooves 23 and the number of spiral grooves 23. The length of the spiral groove 23 affects stress distribution and effective length. The size of the vibration conversion zone is affected by the angle of the spiral groove 23. The conversion efficiency from longitudinal vibration to torsional vibration is affected. Through simulation, the functional relationship between the parameters of the spiral groove 23 and the amplification factor of the amplitude transformer 2 can be obtained.

[0027] Specifically, the amplitude transformer 2 has a hollowed-out center at the transition point from the cutter end to the double-tapered structure 21 to increase the magnification of the amplitude transformer 2.

[0028] Specifically, the piezoelectric ceramic pieces are configured as four pieces.

[0029] Specifically, the cutter tip is tapered in the direction away from the front end of the amplitude rod 2.

[0030] Specifically, the thickness of the rear cover 6 is used for adjusting the resonant frequency. The junction between the ceramic plate and the amplitude transformer 2 is selected as the nodal surface, and the sum of the thicknesses of the ceramic plate and the rear cover 6 is set to... Wavelength, amplitude rod 2 is Wavelength, i.e.: ;in: The back cover is 6mm long; The thickness of the ceramic sheet; The rear cover has 6 wave speeds; For ceramic plate wave velocity; The target operating frequency of the ultrasonic tool holder 1; ceramic sheet thickness. ceramic plate wave velocity Based on the material chosen for back cover 6, the wave speed of back cover 6 can be found. Substituting into the formula, we obtain the length of the back cover (6). .

[0031] Specifically, the length of the amplitude transformer 2 is Wavelength, according to the formula: ;in, The length of the amplitude transformer 2; The wave velocity of amplitude transformer 2 is determined by looking up the material selected for amplitude transformer 2. Substituting into the formula, we obtain the length of the amplitude transformer 2. .

[0032] Specifically, the longitudinal magnification factor of the amplitude transformer 2 Represented as: ;in, , is the longitudinal magnification factor without spiral groove 23, and is the ratio of the contact area between the rear end of the amplitude rod 2 and the piezoelectric ceramic 3 to the cutting edge area of ​​the amplitude rod 2; This is the attenuation factor of the spiral groove 23 on the longitudinal magnification. ; To mitigate the nonlinear relationship between the effect and the number of slots, ; This is the sensitivity index of longitudinal amplitude to helix angle. ; To assess the sensitivity of the longitudinal magnification factor to deviations of the slot length from the optimal value, and considering the materials commonly used for the amplitude transformer 2... ; The optimal length for spiral groove 23 is... , The length of the amplitude transformer 2; the torsional amplification factor of the amplitude transformer 2. Represented as: Among them, Mt0 is the torsional amplification factor without the spiral groove 23, and is the square of the ratio of the contact area between the rear end of the amplitude rod 2 and the piezoelectric ceramic 3 to the area of ​​the cutting end of the amplitude rod 2; To reverse the saturation rate of the amplification factor as the number of slots increases, ; For the nonlinear exponent of the saturation process, ; The strength index for the increase in torsional amplitude, ; This is the scaling correction factor for the helix angle. .

[0033] Specifically, for the two tapers in the double-tapered structure 21 of the amplitude rod 2 , , is represented as: ; ; ;in, The diameter at which the rear end of the amplitude transformer 2 contacts the end of the piezoelectric ceramic plate 3; The diameter of the transition section 22 between the two tapers in the double-tapered structure 21 of the amplitude rod 2; The diameter of the cutter tip of the amplitude transformer 2; The length from the end of the amplitude rod 2 that contacts the ceramic plate to the end of the first taper; The length of the transition section 22 between the two tapers in the double-tapered structure 21 of the amplitude rod 2; The length of the amplitude transformer 2 transitioning to the cutter tip is calculated based on the desired magnification. and The ratio of these values ​​also has the maximum stress: ;in, The Young's modulus of the material selected for the amplitude transformer 2. The target operating frequency of the ultrasonic tool holder 1. The wave velocity of the material selected for amplitude transformer 2 For the maximum input amplitude, The magnification factor of the amplitude transformer 2 is given; where the maximum stress is less than two-thirds of the allowable stress of the material.

[0034] Example 2 This example provides a design method for a longitudinally torsion-bonded robust ultrasonic tool holder 1 for large-diameter cutting tools. Considering the use of large cutting tools and the requirement for high transducer power, a method is selected... piece Piezoelectric ceramic 3, Young's modulus is Poisson's ratio is The density is .

[0035] The design method includes: (1) determining the length of the transducer back cover 6; the transducer back cover 6 mainly provides inertial mass, so that energy radiates in the direction of the amplitude transformer 2, and the thickness can be adjusted according to the requirements to adjust the resonant frequency. The position at the junction of the ceramic plate and the amplitude transformer 2 is selected as the nodal surface, and the sum of the thicknesses of the ceramic plate and the back cover 6 is set as Wavelength, amplitude rod 2 is Wavelength, i.e.: ;in: The back cover is 6mm long; The thickness of the ceramic sheet; The rear cover has 6 wave speeds; For ceramic plate wave velocity; The target operating frequency of the ultrasonic tool holder 1; the length of the amplitude transformer 2 is... Wavelength, according to the formula: ;in, The length of the amplitude transformer 2; For the amplitude transformer 2 wave speed; The target operating frequency of the ultrasonic tool holder 1; ceramic sheet thickness. ceramic plate wave velocity Based on the material chosen for back cover 6, the wave speed of back cover 6 can be found. Substituting into the formula, we obtain the length of the back cover (6). .

[0036] (2) Determine the length of the amplitude transformer 2; the length of the amplitude transformer 2 is Wavelength, according to the formula: ;in, The length of the amplitude transformer 2; The wave velocity of amplitude transformer 2 is determined by looking up the material selected for amplitude transformer 2. Substituting into the formula, we obtain the length of the amplitude transformer 2. The front end of the amplitude rod 2 is an enlarged cone shape used to mount the cutting tool.

[0037] (3) Determine the longitudinal magnification factor of the amplitude transformer 2 and torsional magnification The amplitude transformer 2 is a composite shape, consisting of two tapered sections that first contract and then expand. This design ensures sufficient magnification while also accommodating specialized large cutting tools. The longitudinal magnification of the amplitude transformer 2... Represented as: ;in, , is the longitudinal magnification factor without spiral groove 23, and is the ratio of the contact area between the rear end of the amplitude rod 2 and the piezoelectric ceramic 3 to the cutting edge area of ​​the amplitude rod 2; This is the attenuation factor of the spiral groove 23 on the longitudinal magnification. ; To mitigate the nonlinear relationship between the effect and the number of slots, ; This is the sensitivity index of longitudinal amplitude to helix angle. ; To assess the sensitivity of the longitudinal magnification factor to deviations of the slot length from the optimal value, and considering the materials commonly used for the amplitude transformer 2... ; The optimal length for spiral groove 23 is... , The length of the amplitude transformer 2; the torsional amplification factor of the amplitude transformer 2. Represented as: Among them, M t0 is the torsional amplification factor without the spiral groove 23, and is the square of the ratio of the contact area between the rear end of the amplitude rod 2 and the piezoelectric ceramic 3 to the area of ​​the cutting end of the amplitude rod 2; To reverse the saturation rate of the amplification factor as the number of slots increases, ; For the nonlinear exponent of the saturation process, ; The strength index for the increase in torsional amplitude, ; This is the scaling correction factor for the helix angle. (4) Determine the parameters of the double-tapered structure 21 of the amplitude rod 2; For the two tapers in the double-tapered structure 21 of the amplitude rod 2 , , is represented as: ; ; ;in, The diameter at which the rear end of the amplitude transformer 2 contacts the end of the piezoelectric ceramic plate 3; The diameter of the transition section 22 between the two tapers in the double-tapered structure 21 of the amplitude rod 2; The diameter of the cutter tip of the amplitude transformer 2; The length from the end of the amplitude rod 2 that contacts the ceramic plate to the end of the first taper; The length of the transition section 22 between the two tapers in the double-tapered structure 21 of the amplitude rod 2; The length of the amplitude transformer 2 transitioning to the cutter tip is calculated based on the desired magnification. and The ratio of these values ​​also has the maximum stress: ;in, The Young's modulus of the material selected for the amplitude transformer 2. The target operating frequency of the ultrasonic tool holder 1. The wave velocity of the material selected for amplitude transformer 2 For the maximum input amplitude, The magnification factor of the amplitude transformer 2 is given; where the maximum stress is less than two-thirds of the allowable stress of the material. From this, a suitable magnification factor can be calculated, and thus a suitable size for the amplitude transformer 2 can be determined. Because it needs to accommodate large cutting tools, the center of the transition section 22 between the cutting tool tip and the taper of the amplitude transformer 2 is hollowed out to increase the magnification factor. Finally, the following parameters can be obtained: Specifically, the diameter of the rear end of the amplitude transformer 2 in contact with the end of the piezoelectric ceramic plate 3... The diameter of the transition section 22 between the two tapers of the double-tapered structure 21 of the amplitude rod 2 is... Inner diameter of the cutter end of the amplitude transformer 2 The inner diameter of the transition section 22 between the two tapers of the double-tapered structure 21 of the amplitude rod 2. ; the cutting end of the amplitude transformer 2 The length from the rear end of the amplitude transformer 2 where it contacts the ceramic plate to the end of the first taper. The length of the transition section 22 between the two tapers in the double-tapered structure 21 of the amplitude rod 2. ; Length of the transition bar 2 to the cutter tip Number of spiral grooves 23 ; length of spiral groove 23 ; Angle of spiral groove 23 .

[0038] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0039] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0040] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0041] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0042] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A robust ultrasonic tool holder with longitudinal torsion combination for large-diameter cutting tools, characterized in that, The device includes a tool holder (1) and a transducer disposed within the tool holder (1); the transducer includes an amplitude transformer (2), a piezoelectric ceramic (3) plate, a positive electrode (4), a negative electrode (5), and a rear cover (6); multiple piezoelectric ceramic (3) plates are stacked axially between the rear end of the amplitude transformer (2) and the rear cover (6); the negative electrode (5) and the positive electrode (4) are respectively staggered between two adjacent piezoelectric ceramic (3) plates, and between the rear end of the amplitude transformer (2) and the piezoelectric ceramic (3) plates, and between the rear cover (6) and the piezoelectric ceramic (3) plates; the rear cover (6) is used to provide inertial mass so that energy is radiated in the direction of the amplitude transformer (2); the amplitude transformer (2) is first retracted and then expanded. The double-tapered structure (21) forms a transition section (22) between the two tapers of the double-tapered structure (21). The front end of the amplitude rod (2) is provided with a tool end for mounting the tool. A spiral groove (23) is provided along the axial direction of the amplitude rod (2). The spiral groove (23) is used to convert part of the longitudinal vibration of the amplitude rod (2) into torsional vibration to form a longitudinal-torsional composite vibration. The tool holder (1) is provided with a contact conductive contact (7) and the contact conductive contact (7) is electrically insulated from the tool holder (1). The contact conductive contact (7) is electrically connected to the positive electrode (4) and the negative electrode (5) respectively through a wire. The contact conductive contact (7) is used to power the transducer through contact with the machine tool spindle.

2. The longitudinal-torsion-bonded robust ultrasonic tool holder for large-diameter cutting tools according to claim 1, characterized in that, The amplitude rod (2) has a hollowed-out center at the transition point from the cutter end to the double-tapered structure (21) to increase the magnification of the amplitude rod (2).

3. A robust ultrasonic tool holder with longitudinal torsion combination for large-diameter cutting tools according to claim 1, characterized in that, The piezoelectric ceramic (3) sheet is provided in four pieces.

4. A robust ultrasonic tool holder with longitudinal torsion combination for large-diameter cutting tools according to claim 1, characterized in that, The cutting edge is tapered in an expanding direction away from the front end of the amplitude rod (2).

5. A robust ultrasonic tool holder with longitudinal torsion combination for large-diameter cutting tools according to claim 1, characterized in that, The thickness of the rear cover (6) is used to adjust the resonant frequency. The position where the ceramic plate intersects with the amplitude transformer (2) is selected as the nodal surface, and the sum of the thicknesses of the ceramic plate and the rear cover (6) is set as... Wavelength, amplitude rod (2) is Wavelength, i.e.: ;in: The length of the back cover (6); The thickness of the ceramic sheet; For the back cover (6) wave velocity; For ceramic plate wave velocity; The target operating frequency of the ultrasonic tool holder (1); the thickness of the ceramic sheet ceramic plate wave velocity Based on the material selected for the back cover (6), the wave velocity of the back cover (6) is found. Substituting into the formula, we obtain the length of the back cover (6). 。 6. A robust ultrasonic tool holder with longitudinal torsion combination for large-diameter cutting tools according to claim 1, characterized in that, The length of the amplitude rod (2) is Wavelength, according to the formula: ;in, The length of the amplitude transformer (2); The wave velocity of the amplitude transformer (2) is determined by the material selected for the amplitude transformer (2). Substituting into the formula, we obtain the length of the amplitude transformer (2). 。 7. A robust ultrasonic tool holder with longitudinal torsion combination for large-diameter cutting tools according to claim 1, characterized in that, The longitudinal magnification factor of the amplitude rod (2) Represented as: ;in, is the longitudinal magnification factor without the spiral groove (23), and is the ratio of the contact area between the rear end of the amplitude rod (2) and the piezoelectric ceramic (3) sheet to the cutting end area of ​​the amplitude rod (2); The reduction factor of the longitudinal magnification by the spiral groove (23) is the coefficient. ； To mitigate the nonlinear relationship between the effect and the number of slots, ； This is the sensitivity index of longitudinal amplitude to helix angle. ； To assess the sensitivity of the longitudinal magnification factor to deviations of the slot length from the optimal value, the materials commonly used for the amplitude transformer (2) are... ； For the optimal length of the spiral groove (23), ， The length of the amplitude transformer (2); the torsional magnification factor of the amplitude transformer (2). Represented as: Among them, M t0 is the torsional amplification factor without the spiral groove (23), and is the square of the ratio of the contact area between the rear end of the amplitude rod (2) and the piezoelectric ceramic (3) sheet to the area of ​​the cutting end of the amplitude rod (2); To reverse the saturation rate of the amplification factor as the number of slots increases, ； For the nonlinear exponent of the saturation process, ； The strength index for the increase in torsional amplitude, ； This is the scaling correction factor for the helix angle. 。 8. A robust ultrasonic tool holder with longitudinal torsion combination for large-diameter cutting tools according to claim 1, characterized in that, For the two tapers in the double-tapered structure (21) of the amplitude rod (2), 、 , is represented as: ； ； ;in, The diameter at which the rear end of the amplitude transformer (2) contacts the end of the piezoelectric ceramic (3) sheet; The diameter of the transition section (22) between the two tapers in the double-tapered structure (21) of the amplitude rod (2); The diameter of the cutter end of the amplitude transformer (2); The length from the end of the amplitude rod (2) that contacts the ceramic plate to the end of the first taper; The length of the transition section (22) between the two tapers in the double-tapered structure (21) of the amplitude rod (2); The length of the amplitude transformer (2) transitioning to the cutter tip is obtained based on the desired magnification. and The ratio of these values ​​also has the maximum stress: ;in, The Young's modulus of the material selected for the amplitude transformer (2) is... The target operating frequency of the ultrasonic tool holder (1) is... The wave velocity of the material selected for the amplitude transformer (2) For the maximum input amplitude, The magnification factor of the amplitude transformer (2) is given; where the maximum stress is less than two-thirds of the allowable stress of the material.

9. A robust ultrasonic tool holder with longitudinal torsion combination for large-diameter cutting tools according to claim 1, characterized in that, The diameter of the rear end of the amplitude rod (2) in contact with the end of the piezoelectric ceramic (3) plate The diameter of the transition section (22) between the two tapers of the double-tapered structure (21) of the amplitude rod (2) ; Inner diameter of the cutter end of the amplitude transformer (2) The inner diameter of the transition section (22) between the two tapers of the double-tapered structure (21) of the amplitude rod (2) ; the diameter of the cutter end of the amplitude transformer (2) The length from the end of the amplitude transformer (2) in contact with the ceramic plate to the end of the first taper. The length of the transition section (22) between the two tapers in the double-tapered structure (21) of the amplitude rod (2) ; The length of the amplitude transformer (2) transitioning to the cutter tip Number of spiral grooves (23) ; length of the spiral groove (23) ; Angle of the spiral groove (23) 。 10. A design method for a longitudinally torsion-bonded robust ultrasonic tool holder for large-diameter cutting tools, characterized in that, include: (1) Determine the length of the transducer back cover (6); select the position where the ceramic plate and the amplitude transformer (2) meet as the nodal surface, and set the sum of the thicknesses of the ceramic plate and the back cover (6) as the nodal surface. Wavelength, amplitude rod (2) is Wavelength, i.e.: ;in: The length of the back cover (6); The thickness of the ceramic sheet; For the back cover (6) wave velocity; For ceramic plate wave velocity; The target operating frequency of the ultrasonic knife holder (1); the length of the amplitude transformer (2) is... Wavelength, according to the formula: ;in, The length of the amplitude transformer (2); For the amplitude rod (2) wave velocity; The target operating frequency of the ultrasonic tool holder (1); the thickness of the ceramic sheet ceramic plate wave velocity Based on the material selected for the back cover (6), the wave velocity of the back cover (6) is found. Substituting into the formula, we obtain the length of the back cover (6). (2) Determine the length of the amplitude transformer (2); the length of the amplitude transformer (2) is Wavelength, according to the formula: ;in, The length of the amplitude transformer (2); The wave velocity of the amplitude transformer (2) is determined by the material selected for the amplitude transformer (2). Substituting into the formula, we obtain the length of the amplitude transformer (2). (3) Determine the longitudinal magnification factor of the amplitude transformer (2). and torsional magnification The longitudinal magnification factor of the amplitude transformer (2) Represented as: ;in, is the longitudinal magnification factor without the spiral groove (23), and is the ratio of the contact area between the rear end of the amplitude rod (2) and the piezoelectric ceramic (3) sheet to the cutting end area of ​​the amplitude rod (2); The reduction factor of the longitudinal magnification by the spiral groove (23) is the coefficient. ； To mitigate the nonlinear relationship between the effect and the number of slots, ； This is the sensitivity index of longitudinal amplitude to helix angle. ； To assess the sensitivity of the longitudinal magnification factor to deviations of the slot length from the optimal value, the materials commonly used for the amplitude transformer (2) are... ； For the optimal length of the spiral groove (23), ， The length of the amplitude transformer (2); the torsional magnification factor of the amplitude transformer (2). Represented as: Among them, M t0 is the torsional amplification factor without the spiral groove (23), and is the square of the ratio of the contact area between the rear end of the amplitude rod (2) and the piezoelectric ceramic (3) sheet to the area of ​​the cutting end of the amplitude rod (2); To reverse the saturation rate of the amplification factor as the number of slots increases, ； For the nonlinear exponent of the saturation process, ； The strength index for the increase in torsional amplitude, ； This is the scaling correction factor for the helix angle. (4) Determine the parameters of the double-tapered structure (21) of the amplitude rod (2); For the two tapers in the double-tapered structure (21) of the amplitude rod (2), 、 , is represented as: ； ； ;in, The diameter at which the rear end of the amplitude transformer (2) contacts the end of the piezoelectric ceramic (3) sheet; The diameter of the transition section (22) between the two tapers in the double-tapered structure (21) of the amplitude rod (2); The diameter of the cutter end of the amplitude transformer (2); The length from the end of the amplitude rod (2) that contacts the ceramic plate to the end of the first taper; The length of the transition section (22) between the two tapers in the double-tapered structure (21) of the amplitude rod (2); The length of the amplitude transformer (2) transitioning to the cutter tip is obtained based on the desired magnification. and The ratio of these values ​​also has the maximum stress: ;in, The Young's modulus of the material selected for the amplitude transformer (2) is... The target operating frequency of the ultrasonic tool holder (1) is... The wave velocity of the material selected for the amplitude transformer (2) For the maximum input amplitude, The magnification factor of the amplitude transformer (2) is given; where the maximum stress is less than two-thirds of the allowable stress of the material.

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