A high-accessibility ultrasonic vibration turning elbow tool bar and its design method

Abstract

The present invention discloses a high-accessibility ultrasonic vibration turning elbow tool rod and a design method thereof. The method first calculates the contour size of a workpiece to be processed, determines the size range of the elbow tool rod within which no interference or collision occurs with the workpiece when processing the workpiece, and designs the elbow tool rod within the size range; then, a finite element simulation method is used to determine an amplitude variable rod that meets the contour size of the workpiece to be processed and the resonance characteristics of the elbow tool rod, and then designs an elbow tool rod with a curved amplitude variable rod and a longitudinally curved elliptical ultrasonic transducer. The method performs cyclic iteration according to corresponding situations, and needs to test the final design goal, so as to obtain a high-accessibility ultrasonic vibration turning elbow tool rod, so that the amplitude variable rod is adapted to the contour of the workpiece when designed and has high structural accessibility, solves the structural adaptability problem of the ultrasonic turning tool rod in actual production, and promotes the application of ultrasonic vibration turning in actual production, especially in the production of aviation engine parts with complex inner cavities and outer surfaces.

Description

Technical Field

[0001] The present invention relates to the technical field of processing equipment, in particular to a high-accessibility ultrasonic vibration turning elbow tool bar and a design method thereof. Background Art

[0002] Ultrasonic vibration turning tool bars are key equipment for ultrasonic turning processing. A key issue that limits the actual production application of ultrasonic turning processing is the structural adaptability of ultrasonic turning tool bars. In order to amplify the vibration amplitude generated by piezoelectric ceramics, the cross-section of the amplitude changer is a certain multiple smaller than the front cover plate. In addition, in order to ensure good ultrasonic transmission effects, the ultrasonic transducer is generally a circularly symmetrical rotating body. Therefore, the turning blade at the front end of the amplitude changer is near the axis of the transducer, resulting in interference and collision problems between the ultrasonic turning tool bar and the workpiece during processing. The collision and interference problem between the transducer and the workpiece in the external surface processing of ordinary ultrasonic turning tool bars can be seen in Figure 2 A.

[0003] In particular, aircraft engine components generally have complex internal and external contours. Figure 1 A is a schematic diagram of a common turning tool bar 25 turning the inner cavity of a turbine disc 23. Figure 3 A is a schematic diagram of an ordinary turning tool bar 25 turning the outer surface of the turbine disk 23. The ordinary tool bars used to process these parts are very different from the turning tool bars commonly used in other processing industries. These tool bars have different shapes, complex appearances, and are highly specialized. In order to avoid interference and collision between the tool bar and the workpiece, the ordinary turning tool bars 25 must be customized to meet accessibility requirements. The existing ultrasonic vibration turning tool bars have the problem of collision and interference between the amplitude rod and the workpiece and cannot be used in the manufacture of complex aerospace parts.

[0004] Ultrasonic vibration machining is preferably used in the machining of difficult-to-machine materials due to its many advantages. The high-speed ultrasonic vibration cutting method developed by Zhang Deyuan's team at the Beijing University of Aeronautics and Astronautics has solved the problem that traditional ultrasonic vibration cutting cannot perform high-speed machining, and has achieved high-speed ultrasonic machining of difficult-to-machine materials such as nickel-based high-temperature alloys and titanium alloys. The tool tip of high-speed ultrasonic vibration cutting vibrates laterally along the surface, avoiding the chipping of the tool tip caused by vibration impact in the cutting depth direction. In order to adapt to the widespread application of continuous CNC tool-feeding machining of surfaces with multi-directional changes, the present invention has proposed a practical high-speed ultrasonic vibration cutting method with elliptical vibration of the tool base surface. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-accessibility ultrasonic vibration turning elbow tool rod and its design method to solve the problems existing in the above-mentioned prior art, solve the interference and collision problems between the transducer and the workpiece and between the amplitude rod and the workpiece during vibration turning of ordinary ultrasonic turning tool rods, solve the structural adaptability problems of ultrasonic turning tool rods in actual production, and promote the application of ultrasonic vibration turning in actual production, especially in the production of aviation engine parts with complex contours such as inner cavities and outer surfaces.

[0006] To achieve the above object, the present invention provides the following solution: The present invention provides a design method for a high-accessibility ultrasonic vibration turning elbow tool bar, comprising the following steps:

[0007] S1. Calculate the outline size of the workpiece to be machined, determine the size range of the elbow tool arbor within which no interference or collision occurs with the workpiece during machining, and design the elbow tool arbor within this size range;

[0008] When designing the elbow tool rod, the horn of the elbow tool rod is taken as the design object, an ultrasonic transducer with a frequency similar to that of the horn is estimated, and the ultrasonic transducer and the horn are combined to form the elbow tool rod for simulation design;

[0009] S2. Determine, by finite element simulation, the amplitude transformer that meets the contour dimensions of the workpiece to be machined and the resonance characteristics of the bent tool bar: estimate the cross-sectional dimensions of a set of amplitude transformers based on the amplitude transformer stiffness and resonance frequency requirements, design the bent tool bar into a tool bar with a straight amplitude transformer longitudinal vibration transducer within a predetermined frequency range, and determine the length of the amplitude transformer;

[0010] When the length of the horn is known, the cross-sectional dimensions of the horn are adjusted to match the tool bar with the straight horn longitudinal vibration transducer to a tool bar with a straight variable amplitude longitudinal curved elliptical ultrasonic transducer;

[0011] When there are difficulties in matching the two paths of the tool bar with the straight variable amplitude longitudinal curved elliptical ultrasonic transducer, the frequency difference is made less than 300 Hz, and in the subsequent debugging stage, the two paths are made to vibrate at the same frequency through impedance matching;

[0012] S3. Design of the elbow blade with a curved horn and a longitudinally curved elliptical ultrasonic transducer: The horn is bent so that the axis of the horn and the axis of the longitudinally curved elliptical ultrasonic transducer of the curved horn form an angle. By adjusting the angle, the longitudinal and bending vibration directions of the longitudinally curved elliptical ultrasonic transducer of the curved horn are nearly perpendicular to each other. At the desired angle, the length of the horn is adjusted to adjust the distance that the horn extends beyond the outermost side of the longitudinally curved elliptical ultrasonic transducer of the curved horn.

[0013] S4. In step S2 and step S3, loop iteration is performed according to the corresponding situation, and the final design goal needs to be tested, so as to obtain the high-accessibility ultrasonic vibration turning elbow tool rod, that is, the tool rod with a curved amplitude rod and a longitudinally curved elliptical ultrasonic transducer.

[0014] Preferably, according to the contour structure of the workpiece to be processed, the vibration direction of the bent tool rod is selected as single-direction vibration or multi-directional composite vibration.

[0015] Preferably, the vibration frequency of the elbow cutter bar is selected between 10 and 40 kHz.

[0016] Preferably, the bent tool bar is used for any one of external turning, external profiling turning, end turning, internal hole turning, internal hole profiling, grooving, cutting and thread turning.

[0017] Preferably, the amplitude change rod used for the rough elbow ultrasonic turning tool rod is a square rod that forms a required angle with the center axis of the tool rod, and the tip of the turning blade connected to the amplitude change rod is located at the outermost side of the rough elbow ultrasonic turning tool rod.

[0018] Preferably, the amplitude variable rod used for the thin straight ultrasonic turning tool rod includes a square rod parallel to the central axis of the tool rod, and a square piece located at the front end of the square rod and parallel to it. The front end structure of the amplitude variable rod matches the contour shape of the workpiece to be processed.

[0019] Preferably, the amplitude varying rod used for the thin elbow ultrasonic turning tool rod includes a square rod parallel to the central axis of the tool rod, and a square piece connected to the front end of the square rod and arranged at an angle thereto. The structure of the amplitude varying rod matches the contour shape of the workpiece to be processed.

[0020] Furthermore, a high-accessibility ultrasonic vibration turning elbow tool bar is provided, comprising a tool bar fixture and an ultrasonic transducer and a bending amplitude rod mounted on the tool bar fixture, wherein a turning blade is mounted on one end of the bending amplitude rod, and a pre-tightening bolt is integrally formed on the other end, a front cover plate is integrally formed on the end of the pre-tightening bolt close to the amplitude rod, and a rear cover plate is coaxially rotatably connected to the pre-tightening bolt.

[0021] The ultrasonic transducer includes a piezoelectric ceramic ring clamped between the front cover plate and the rear cover plate, and the piezoelectric ceramic ring is coaxially rotatably mounted on the pre-tightening bolt;

[0022] The tool bar fixture is provided with a groove for the pre-tightening bolt, the piezoelectric ceramic ring and the rear cover plate to extend into, the front cover plate is buckled at the opening of the groove, and a sealing ring is provided between the front cover plate and the end face of the tool bar fixture, and the sealing ring surrounds the outer circumference of the groove opening;

[0023] A plurality of guide holes are formed on the tool bar clamp along the radial direction of the groove, and the guide holes are evenly spaced along the circumference of the groove. A support bolt and a sealing and clamping bolt are connected to the inner threads of the guide holes. The support bolt abuts against the outer peripheral wall of the rear cover plate, and the clamping bolt is located on the side of the support bolt away from the rear cover plate. An insulating sealing gasket is provided between the sealing and clamping bolt and the support bolt.

[0024] The tool rod clamp is also provided with a waterproof aviation plug electrically connected to the electrode ring, and a rubber sealing gasket is provided between the plug and the tool rod clamp.

[0025] Preferably, an annular flange surrounds the outer peripheral edge of the front cover plate, the annular flange abuts against the end surface of the tool bar clamp located on the outer peripheral side of the groove opening, and is connected to the tool bar clamp by a plurality of fixing bolts, and the fixing bolts are evenly spaced along the circumference of the annular flange;

[0026] An annular groove is provided on the end surface of the annular flange close to the tool rod clamp. The annular groove is located on the inner circumference of each fixing bolt, and the sealing ring abutting on the tool rod clamp is embedded in the annular groove.

[0027] Preferably, a plurality of arc grooves are provided on the end surface of the annular flange close to the tool rod clamp, each of the arc grooves is coaxially arranged with the annular flange and is evenly spaced along the circumference of the annular flange, and each of the arc grooves is located on the inner circumference side of the groove opening.

[0028] Compared with the prior art, the present invention has achieved the following technical effects:

[0029] The horn of the present invention is detachably connected to the tool bar clamp through the front cover plate, and a series of ultrasonic turning tool bars with different uses, shapes and comprehensive specifications can be selected according to different working conditions. The horn can be designed to be straight, curved, thick, thin, etc. to avoid interference and collision and improve the accessibility of the ultrasonic tool bar, such as a thick elbow ultrasonic turning tool bar, a thin elbow ultrasonic turning tool bar, and a thin straight ultrasonic turning tool bar. Ordinary ultrasonic turning tool bars can only be used for the processing of simple shape parts, such as outer circle and end face turning, and cannot meet the needs of actual production. The ultrasonic turning tool bar of the present invention has a wide range of uses and can be used for outer circle turning, outer circle profiling turning, end face turning, inner hole turning, inner hole profiling processing, grooving processing, cutting processing, thread turning and the inner and outer shape contours of parts. The present invention solves the problem of interference and collision between the transducer and the workpiece and between the horn and the workpiece during ultrasonic vibration turning, solves the structural adaptability problem of the ultrasonic turning tool bar in actual production, and promotes the application of ultrasonic vibration turning in actual production, especially in the production of aircraft engine parts with complex inner cavities and outer surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A is a schematic diagram of turning the inner cavity of a turbine disk using an ordinary turning tool bar.

[0032] Figure 1 B is a schematic diagram of the high accessibility of a thin elbow ultrasonic turning tool bar in turning the inner cavity of a turbine disk.

[0033] Figure 2 A is a schematic diagram of the collision and interference problem between the transducer and the workpiece in the surface machining of an ordinary ultrasonic turning tool bar.

[0034] Figure 2 B is a schematic diagram of the high accessibility of the rough elbow ultrasonic turning tool bar for turning the outer surface.

[0035] Figure 3 A is a schematic diagram of turning the outer surface of a turbine disk using an ordinary turning tool bar.

[0036] Figure 3 B is a schematic diagram of the high accessibility of a thin straight ultrasonic turning tool bar in turning the outer surface of a turbine disk.

[0037] Figure 4 A is the first-order longitudinal vibration mode of the thick elbow ultrasonic transducer

[0038] Figure 4 B is the second-order bending vibration mode of the thick elbow ultrasonic transducer

[0039] Figure 5 This is the exploded view of the rough elbow ultrasonic turning tool bar assembly.

[0040] Figure 6 This is a cross-sectional view of the ultrasonic turning tool rod for rough elbows.

[0041] Figure 7 It is a structural schematic diagram of the mounting surface of the front cover plate of the ultrasonic turning tool bar in the present invention.

[0042] Figure 8 This is a schematic diagram of the structure of the amplitude change rod and front cover plate of the thin straight ultrasonic turning tool rod.

[0043] Figure 9 This is a schematic diagram of the structure of the amplitude rod and front cover of the thin elbow ultrasonic turning tool rod.

[0044] Figure 10 Schematic diagram of the installation method of the turning blade of the thin elbow ultrasonic turning tool bar.

[0045] Figure 11 Schematic diagram of the finite element simulation process of the present invention;

[0046] Among them, 1-amplitude transformer, 2-fixing bolt, 3-insulating sleeve, 4-rubber sealing gasket, 5-aviation plug fastening screw, 6-aviation plug female socket, 7-tool bar fixture, 8-sealing gasket, 9-support bolt, 10-tensioning bolt, 11-rear cover, 12-whole ceramic sheet, 13-sealing ring, 14-half ceramic sheet, 15-copper electrode, 16-turning blade, 17-blade clamping screw, 18-lathe chuck, 19-workpiece, 20-ordinary ultrasonic turning tool bar, 21-thick elbow ultrasonic turning tool bar, 22-thin elbow ultrasonic turning tool bar, 23-turbine disc, 24-thin straight head ultrasonic turning tool bar, 25-ordinary turning tool bar. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] The purpose of the present invention is to provide a high-accessibility ultrasonic vibration turning elbow tool rod and its design method to solve the problems existing in the above-mentioned prior art, solve the interference and collision problems between the transducer and the workpiece and between the amplitude rod and the workpiece during vibration turning of ordinary ultrasonic turning tool rods, solve the structural adaptability problems of ultrasonic turning tool rods in actual production, and promote the application of ultrasonic vibration turning in actual production, especially in the production of aviation engine parts with complex contours such as inner cavities and outer surfaces.

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] like Figure 4 and Figure 11 As shown, this embodiment provides a design method for a high-accessibility ultrasonic vibration turning elbow tool bar, comprising the following steps:

[0051] S1. Calculate the outline size of the workpiece to be machined, determine the size range of the elbow toolholder within which no interference or collision occurs when machining the workpiece, and design the elbow toolholder within this size range;

[0052] When designing an elbow tool bar, the horn of the elbow tool bar is taken as the design object, and an ultrasonic transducer with a frequency similar to that of the horn is estimated. The ultrasonic transducer and the horn are combined into an elbow tool bar for simulation design;

[0053] S2. Determine the horn that meets the workpiece profile and the resonance characteristics of the elbow toolholder using finite element simulation: Estimate the cross-sectional dimensions of a set of horns based on the horn stiffness and resonance frequency requirements. Within a predetermined frequency range, design the elbow toolholder into a toolholder with a straight horn longitudinal vibration transducer, and determine the horn length.

[0054] When the length of the horn is known, the cross-sectional size of the horn is adjusted, and then the tool rod with a straight horn longitudinal vibration transducer is matched to a tool rod with a straight variable amplitude longitudinal curved elliptical ultrasonic transducer;

[0055] When there are difficulties in matching the two paths of the tool bar with a straight variable amplitude longitudinal curved elliptical ultrasonic transducer, the frequency difference is made less than 300Hz, and in the subsequent debugging stage, the two paths are made to vibrate at the same frequency through impedance matching;

[0056] S3. Design of an elbow blade with a curved horn and a longitudinally curved elliptical ultrasonic transducer: The horn is bent so that the axis of the horn and the axis of the longitudinally curved elliptical ultrasonic transducer of the curved horn form an angle. By adjusting the angle, the longitudinal and bending vibration directions of the longitudinally curved elliptical ultrasonic transducer of the curved horn are made nearly perpendicular to each other. At the desired angle, the length of the horn is adjusted to adjust the distance that the horn extends outward from the outermost side of the longitudinally curved elliptical ultrasonic transducer of the curved horn.

[0057] S4. In step S2 and step S3, loop iteration is performed according to the corresponding situation, and the final design goal needs to be tested, so that a high-accessibility ultrasonic vibration turning elbow tool rod can be obtained, that is, a tool rod with a curved amplitude rod and a longitudinally curved elliptical ultrasonic transducer.

[0058] According to the contour structure of the workpiece to be machined, the vibration direction of the elbow tool bar is selected as single-direction vibration or multi-directional composite vibration. The tool base surface vibrates elliptically and is equipped with this type of piezoelectric ceramic ring stack. The modal simulation design realizes that when the amplitude change rod 1 of the ordinary ultrasonic turning tool bar 20 is changed from a uniform straight rod to a curved rod with uneven thickness, it can still excite stable resonant ultrasonic vibration. The vibration form of the elbow tool bar shown in the present invention is a base surface ellipse, but it is not limited to this. By replacing the ceramic sheet, one-dimensional vibration, two-dimensional vibration and three-dimensional vibration can be achieved.

[0059] Preferably, the vibration frequency of the elbow cutter bar is selected between 10 and 40 kHz. Figure 5 The horn 1 and the front cover are replaced with Figure 8 and Figure 9The ultrasonic turning tool bars obtained by the middle amplitude transformer 1 and the front cover plate both have a fixed frequency. However, as the structural dimensions are adjusted, a range of ultrasonic tool bars with vibration frequencies between 10 and 40 kHz can be included. Furthermore, the frequencies of the multi-channel vibration coupling tool bars can be the same or have different frequencies. The elliptical trajectory of the tool bar with the same frequency does not change over time, while the elliptical trajectory of the elliptical tool bar with different frequencies changes with a fixed period over time due to the frequency difference.

[0060] The bent tool bar is used for any of external turning, external profiling, face turning, internal turning, internal profiling, grooving, cutting, and thread turning. It should be noted that the horn 1 can be designed to be straight, curved, thick, thin, etc., thereby enabling the selection of a series of contour-adaptable turning tool bars with different uses, shapes, and specifications, such as a thick bent ultrasonic turning tool bar 21, a thin bent ultrasonic turning tool bar 22, and a thin straight ultrasonic turning tool bar 24, to avoid interference and collision between the transducer and the workpiece 19, and between the tool bar and the workpiece 19, during ultrasonic vibration turning. This solves the problem of the thin straight horn 1 of the conventional ultrasonic turning tool bar 20 being located at the rotation center of the thick transducer, preventing the ultrasonic vibration tool bar tip from being at the outermost edge of the entire tool bar, which easily leads to structural interference between the tool bar and the workpiece 19 during turning. This promotes the application of ultrasonic vibration turning in actual production, especially in the production of aircraft engine parts with complex internal cavities and external surfaces. Ordinary ultrasonic turning tool bar 20 can only be used for processing simple shape parts, such as outer circle and end face turning, which cannot meet the needs of actual production, such as Figure 2 As shown in Figure A, the contour shape of the workpiece 19 and the resonant characteristics of the transducer define the design space for the ultrasonic vibration turning elbow tool bar. The tool bar of the present invention has a wide range of applications, including external turning, external profiling, facing, internal turning, internal profiling, grooving, cutting, thread turning, and the internal and external contours of parts. For example, the thick elbow ultrasonic turning tool bar 21 can be used for external turning, external profiling, and facing, while the thin elbow ultrasonic turning tool bar 22 can be used for external profiling and internal cavity turning, and the thin straight ultrasonic turning tool bar 24 can be used for external profiling and grooving.

[0061] As a preferred embodiment of the present invention, Figure 2 B and Figure 5 As shown, the amplitude variable rod used for the rough elbow ultrasonic turning tool rod is a square rod that forms a required angle with the center axis of the tool rod. The tip of the turning blade connected to the amplitude variable rod is located at the outermost side of the rough elbow ultrasonic turning tool rod, thereby avoiding the interference and collision problem between the transducer and the workpiece 19 during ultrasonic vibration turning. The function of the rough elbow ultrasonic turning tool rod 21 is similar to that of an ordinary deflected tool rod. The elbow means that the straight rod of the ordinary ultrasonic turning tool rod 20 is changed into a curved rod so that the front end of the amplitude variable rod 1 extends to the outside of the tool rod, thereby avoiding possible interference and collision during processing.

[0062] As another preferred embodiment of the present invention, Figure 3 B and Figure 8 As shown, the horn used in a thin straight ultrasonic turning tool bar includes a square bar parallel to the tool bar's central axis and a square plate located at the front end of the square bar and parallel to it. The front end structure of the horn matches the contour of the workpiece to be machined. The front end of the horn 1 adapts to the contour of the part, avoiding interference and collision between the horn 1 and the workpiece 19 during ultrasonic vibration turning. The thin straight ultrasonic turning tool bar 24 is similar to combining a conventional thin straight turning tool bar as the horn 1 and the front cover of the ultrasonic transducer to achieve ultrasonic vibration machining of complex external surfaces of aircraft engine workpieces 19.

[0063] As another preferred embodiment of the present invention, Figure 1 B and Figure 9 As shown, the horn used for the thin elbow ultrasonic turning tool bar includes a square bar parallel to the tool bar's central axis and a square plate connected to the front end of the square bar and arranged at an angle thereto. The horn structure matches the contour of the workpiece to be machined. The horn 1 adapts to the contour of the workpiece 19 and avoids the interference and collision between the horn 1 and the workpiece 19 during ultrasonic vibration turning. The thin elbow ultrasonic turning tool bar 22 is similar to combining an ordinary thin elbow turning tool bar as the horn 1 and the front cover of the ultrasonic transducer to achieve ultrasonic vibration machining of the inner cavity of an aircraft engine workpiece 19.

[0064] Further, such as Figures 5 to 10 As shown, this embodiment provides a high-accessibility ultrasonic vibration turning elbow tool bar, including a tool bar fixture 7 and a horn 1 for mounting a turning blade 16. Specifically, the turning blade 16 is mounted in a tool groove milled at the front end of the horn 1, and the turning blade 16 is clamped by a blade clamping screw 17 or clamped by a self-locking structure, such as Figure 10 As shown, it shows that the blade on the thin elbow ultrasonic turning tool rod 22 is clamped at the front end of the amplitude transformer 1 through a self-locking structure, and there is no blade clamping screw 17. This design is to avoid interference between the clamping part of the turning blade 16 and the cavity wall during inner cavity processing.

[0065] The end of the amplitude rod 1 where the turning blade 16 is not installed is provided with a pre-tightening bolt, and a front cover is provided between the pre-tightening bolt and the amplitude rod 1. Preferably, the amplitude rod 1, the pre-tightening bolt and the front cover are integrally formed to form an integral structure; a groove for the pre-tightening bolt to extend into is provided on the tool rod clamp 7, and a plurality of piezoelectric ceramic rings coaxially sleeved on the pre-tightening bolt are provided in the groove. The piezoelectric ceramic rings are stacked and placed, and the front cover is buckled at the opening of the groove. Specifically, the front cover is detachably connected to the tool rod clamp 7, and a rear cover 11 is also sleeved on the pre-tightening bolt to tighten the piezoelectric ceramic rings to the front cover. Specifically, the rear cover 11 is threadedly sleeved on the pre-tightening bolt, and the rear cover 11 and the front cover are respectively connected to the corresponding piezoelectric ceramic rings and An electrode ring is provided between each adjacent piezoelectric ceramic ring. The electrode ring is a copper electrode 15. The electrode ring has a ring-shaped structure and is sleeved on the pre-tightening bolt. The tool rod clamp 7 is also provided with a waterproof aviation plug electrically connected to the electrode ring. The aviation plug socket 6 is detachably mounted on the tool rod clamp through the aviation plug fastening screw 5, and a rubber sealing gasket 4 is added between the aviation plug socket 6 and the tool rod clamp 7 to seal the position of the tool rod clamp 7 for installing the plug to prevent leakage and cutting fluid infiltration, and to facilitate disassembly; and an insulating structure is provided between the inner peripheral edge of the piezoelectric ceramic ring and the electrode ring and the pre-tightening bolt. The insulating structure is an insulating sleeve 3 coaxially sleeved on the pre-tightening bolt, and each piezoelectric ceramic ring is sleeved on the outer peripheral side of the insulating sleeve 3. It should be further explained that the horn 1, the front cover, the rear cover 11, the copper electrode 15 and the piezoelectric ceramic together constitute the ultrasonic turning transducer part, which is a sandwich Langevin transducer. The horn 1, the front cover and the rear cover 11 are combined into an ultrasonic vibrator.

[0066] As a preferred embodiment of the present invention, each piezoelectric ceramic ring is respectively an integral annular structure and / or an annular structure formed by splicing two semicircular structures. The piezoelectric ceramic ring of the integral annular structure is a whole ceramic sheet 12, and the piezoelectric ceramic ring of the semicircular structure is a half ceramic sheet 14. The tool base surface vibrates elliptically and is equipped with a corresponding type of piezoelectric ceramic ring stack. The modal simulation design realizes that when the amplitude change rod 1 of the ordinary ultrasonic turning tool rod 20 is changed from a uniform straight rod to a curved rod with uneven thickness, it can still excite stable resonant ultrasonic vibration. With the change of structural dimensions, a series of elbow tool rods containing the required vibration frequency are obtained. For the multi-way coupling tool rod, the frequencies of several channels can be the same frequency or have a difference in frequency. The vibration form of the elbow tool rod shown in the present invention is a base surface ellipse, but it is not limited to this. One-dimensional vibration, two-dimensional vibration and three-dimensional vibration can be achieved by replacing the ceramic sheet.

[0067] like Figure 5As shown, the piezoelectric ceramic ring configuration can generate base surface elliptical ultrasonic vibration. When all the piezoelectric ceramic rings are replaced with whole-piece piezoelectric ceramic rings, longitudinal vibration can be generated. When all the piezoelectric ceramic rings are replaced with half-piece piezoelectric ceramic rings, single bending vibration and double bending elliptical vibration can be generated according to different placements. When two whole-piece piezoelectric ceramic rings are selected, 8 half-piece piezoelectric ceramic rings are added. Specifically, six groups of piezoelectric ceramic rings are sequentially sleeved with pre-tightening bolts along their axial direction. The two groups of piezoelectric ceramic rings close to the rear cover plate 11 are integral annular structures, and the four groups of piezoelectric ceramic rings close to the front cover plate are all annular structures spliced together by two semicircular structures. The half-piece dividing lines of the first two groups of piezoelectric ceramic rings and the last two groups of piezoelectric ceramic rings are perpendicular to each other, which can generate a three-dimensional elliptical vibration coupled with one longitudinal vibration and two bending vibrations.

[0068] Among them, the outer peripheral edge of the front cover is surrounded by an annular flange, which abuts against the end face of the tool bar clamp 7 located on the outer peripheral side of the groove opening, and is connected to the tool bar clamp 7 by a plurality of fixing bolts 2. Each fixing bolt 2 is evenly spaced along the circumference of the annular flange. The support method of the annular flange plus the fixing bolts 2 has good support. In addition, the large-diameter amplitude rod 1 can enhance the overall rigidity of the ultrasonic tool bar, thereby improving the cutting parameters applicable to the tool bar, and can be used for the fine processing of difficult-to-process materials, while the existing ordinary ultrasonic turning tool bar 20 can only be used for precision and ultra-precision processing. Furthermore, the support method of the annular flange plus the fixing bolts 2 can effectively improve the positioning accuracy. The support method of the two sets of front and rear screws in the existing technology cannot ensure the consistency of the tool angle before and after disassembly and assembly, and is completely dependent on human vision. The present invention ensures high positioning accuracy by positioning between the end face of the annular flange and the tool bar clamp 7, and between the fixing bolts 2 and the tool bar clamp 7.

[0069] Preferably, an annular groove is provided on the end face of the annular flange close to the tool rod clamp 7, the annular groove is located on the inner circumference of each fixing bolt 2, and a sealing ring 13 abutting against the tool rod clamp 7 is embedded in the annular groove. By providing the sealing ring 13 to seal the gap between the front cover plate and the tool rod clamp 7, it can be used in cutting environments of high-pressure gas, liquid, and mist, and can be ensured not to penetrate even when immersed in liquid.

[0070] Furthermore, a plurality of arcuate grooves are formed on the end surface of the annular flange near the tool bar fixture 7. Each arcuate groove is coaxially arranged with the annular flange and is evenly spaced along the circumference of the annular flange, leaving only a small wall thickness to connect the portion located on the inner circumference of the arcuate groove with the portion located on the outer circumference of the arcuate groove, thereby reducing the annular flange's suppression of the vibration of the front cover plate and the horn 1. Preferably, each arcuate groove is located on the inner circumference of the groove opening to further avoid the arcuate groove being located between the annular flange and the tool bar fixture 7, resulting in insufficient weakening of vibration suppression.

[0071] As a preferred embodiment of the present invention, a plurality of guide holes are provided on the tool bar fixture 7 along the radial direction of the groove. The guide holes are evenly spaced along the circumference of the groove. Support bolts 9 that press against the outer wall of the rear cover plate 11 are threadedly connected in the guide holes. At the same time, a clamping bolt 10 is also threadedly connected in the guide holes. The clamping bolt 10 is located on the side of the support bolt 9 away from the rear cover plate 11 and is used to press against the support bolt 9. A sealing gasket 8 is also provided between the clamping bolt 10 and the support bolt 9 to seal the guide holes. A sealing ring 13 is provided at the position of the tool bar fixture 7 corresponding to the front cover plate, and the position of the corresponding plug is also sealed by a sealing gasket, so that all interfaces opened on the structure are well sealed, and can be used in cutting environments of high-pressure gas, liquid, and mist, and can be ensured to be non-infiltrated even when immersed in liquid.

[0072] Adaptive changes based on actual needs are all within the scope of protection of the present invention.

[0073] It should be noted that it will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0074] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A design method for a high-accessibility ultrasonic vibration turning elbow tool bar, characterized in that: The steps include: S1. Calculate the outline size of the workpiece to be machined, determine the size range of the elbow tool arbor within which no interference or collision occurs with the workpiece during machining, and design the elbow tool arbor within this size range; When designing the elbow tool rod, the horn of the elbow tool rod is taken as the design object, an ultrasonic transducer with a frequency similar to that of the horn is estimated, and the ultrasonic transducer and the horn are combined to form the elbow tool rod for simulation design; S2. Determine, by finite element simulation, the amplitude transformer that meets the contour dimensions of the workpiece to be machined and the resonance characteristics of the bent tool bar: estimate the cross-sectional dimensions of a set of amplitude transformers based on the amplitude transformer stiffness and resonance frequency requirements, design the bent tool bar into a tool bar with a straight amplitude transformer longitudinal vibration transducer within a predetermined frequency range, and determine the length of the amplitude transformer; When the length of the horn is known, the cross-sectional dimensions of the horn are adjusted to match the tool bar with the straight horn longitudinal vibration transducer to a tool bar with a straight variable amplitude longitudinal curved elliptical ultrasonic transducer; When there are difficulties in matching the two paths of the tool bar with the straight variable amplitude longitudinal curved elliptical ultrasonic transducer, the frequency difference is made less than 300 Hz, and in the subsequent debugging stage, the two paths are made to vibrate at the same frequency through impedance matching; S3. Design of the elbow blade with a curved horn longitudinally curved elliptical ultrasonic transducer: bend the horn so that the axis of the horn and the axis of the curved horn longitudinally curved elliptical ultrasonic transducer form an angle, and by adjusting the angle, the longitudinal vibration and the bending vibration directions of the curved horn longitudinally curved elliptical ultrasonic transducer are nearly perpendicular to each other; At a desired angle value, the distance from the outermost side of the longitudinally curved elliptical ultrasonic transducer of the curved horn to the outermost side of the curved horn is adjusted by adjusting the length of the horn; S4. In step S2 and step S3, loop iteration is performed according to the corresponding situation, and the final design goal needs to be tested, so as to obtain the high-accessibility ultrasonic vibration turning elbow tool rod, that is, the tool rod with a curved amplitude rod and a longitudinally curved elliptical ultrasonic transducer.

2. The design method of the high-accessibility ultrasonic vibration turning elbow tool bar according to claim 1 is characterized in that: According to the contour structure of the workpiece to be processed, the vibration direction of the bent tool bar is selected as single-direction vibration or multi-directional composite vibration.

3. The design method of the high-accessibility ultrasonic vibration turning elbow tool bar according to claim 2 is characterized in that: The vibration frequency of the elbow cutter bar is selected between 10 and 40 kHz.

4. The design method of the high-accessibility ultrasonic vibration turning elbow tool bar according to claim 2 or 3, characterized in that: The bent tool bar is used for any one of external turning, external profiling turning, end face turning, internal hole turning, internal hole profiling processing, grooving processing, cutting processing and thread turning.

5. The design method of the high-accessibility ultrasonic vibration turning elbow tool bar according to claim 4 is characterized in that: The amplitude variable rod used for the rough elbow ultrasonic turning tool rod is a square rod that forms a required angle with the center axis of the tool rod, and the tip of the turning blade connected to the amplitude variable rod is located at the outermost side of the rough elbow ultrasonic turning tool rod.

6. The design method of the high-accessibility ultrasonic vibration turning elbow tool bar according to claim 4 is characterized in that: The amplitude variable rod used for the thin straight ultrasonic turning tool rod includes a square rod parallel to the central axis of the tool rod and a square piece located at the front end of the square rod and parallel to it. The front end structure of the amplitude variable rod matches the contour shape of the workpiece to be processed.

7. The design method of the high-accessibility ultrasonic vibration turning elbow tool bar according to claim 4 is characterized in that: The amplitude variable rod used for the thin elbow ultrasonic turning tool rod includes a square rod parallel to the central axis of the tool rod, and a square piece connected to the front end of the square rod and arranged at an angle thereto. The structure of the amplitude variable rod matches the contour shape of the workpiece to be processed.

8. A high-accessibility ultrasonic vibration turning elbow tool bar using the design method of the high-accessibility ultrasonic vibration turning elbow tool bar according to any one of claims 1 to 7, characterized in that: The invention comprises a tool bar fixture and an ultrasonic transducer and a bending amplitude rod mounted on the tool bar fixture. A turning blade is mounted on one end of the bending amplitude rod and a pre-tightening bolt is integrally formed on the other end. A front cover plate is integrally formed on the end of the pre-tightening bolt close to the amplitude rod, and a rear cover plate is coaxially connected to the pre-tightening bolt. The ultrasonic transducer includes a piezoelectric ceramic ring clamped between the front cover plate and the rear cover plate, and the piezoelectric ceramic ring is coaxially rotatably mounted on the pre-tightening bolt; The tool bar fixture is provided with a groove for the pre-tightening bolt, the piezoelectric ceramic ring and the rear cover plate to extend into, the front cover plate is buckled at the opening of the groove, and a sealing ring is provided between the front cover plate and the end face of the tool bar fixture, and the sealing ring surrounds the outer circumference of the groove opening; A plurality of guide holes are formed on the tool bar clamp along the radial direction of the groove, and the guide holes are evenly spaced along the circumference of the groove. A support bolt and a sealing and clamping bolt are connected to the inner threads of the guide holes. The support bolt abuts against the outer peripheral wall of the rear cover plate, and the clamping bolt is located on the side of the support bolt away from the rear cover plate. An insulating sealing gasket is provided between the sealing and clamping bolt and the support bolt. Electrode rings are provided between the rear cover plate and the front cover plate and the corresponding piezoelectric ceramic rings, and between two adjacent piezoelectric ceramic rings, and the tool rod clamp is also provided with a waterproof aviation plug electrically connected to the electrode rings, and a rubber sealing gasket is provided between the plug and the tool rod clamp.

9. The high-accessibility ultrasonic vibration turning elbow tool bar according to claim 8, characterized in that: An annular flange surrounds the outer peripheral edge of the front cover, the annular flange abuts against the end surface of the tool bar clamp located on the outer peripheral side of the groove opening, and is connected to the tool bar clamp by a plurality of fixing bolts, each of the fixing bolts being evenly spaced along the circumference of the annular flange; An annular groove is provided on the end surface of the annular flange close to the tool rod clamp. The annular groove is located on the inner circumference of each fixing bolt, and the sealing ring abutting on the tool rod clamp is embedded in the annular groove.

10. The high-accessibility ultrasonic vibration turning elbow tool bar according to claim 9, characterized in that: A plurality of arcuate grooves are provided on the end surface of the annular flange close to the tool rod clamp. Each of the arcuate grooves is coaxially arranged with the annular flange and is evenly spaced along the circumference of the annular flange. Each of the arcuate grooves is located on the inner circumference of the groove opening.

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