A large amplitude ultrasonic vibration cutting device

Abstract

The present invention relates to a large-amplitude ultrasonic vibration cutting device, comprising a piezoelectric transducer, a primary horn, a secondary horn, an elastic horn, a cutter head and a high-frequency power supply, wherein the piezoelectric transducer comprises a bolt and a rear cover plate, a piezoelectric ceramic sheet, an electrode sheet and a primary horn which are sequentially sleeved on the bolt from back to front and connected and pressed together, the secondary horn is fixed at the front end of the primary horn, the elastic horn is fixed at the front end of the secondary horn, the cutter head is fixed at the front end of the elastic horn, the electrode sheet is connected to the high-frequency power supply, the high-frequency power supply can provide an ultrasonic electric signal to the piezoelectric ceramic sheet through the electrode sheet, so that the piezoelectric ceramic sheet drives the entire piezoelectric transducer to generate axial vibration, and the primary horn, the secondary horn and the elastic horn amplify the vibration amplitude of the piezoelectric transducer step by step. The present invention can effectively improve the output power and amplitude ratio of the transducer, and under the condition of equal power, can effectively increase the vibration amplitude of the cutting knife and improve the motor-machine conversion efficiency.

Description

Technical Field

[0001] The invention relates to the field of ultrasonic vibration utilizing the inverse piezoelectric effect of piezoelectric ceramics, and in particular to a large-amplitude longitudinal vibration cutting device. Background Art

[0002] Ultrasonic cutting is a new process technology that uses ultrasonic piezoelectric transducers to drive cutting tools to generate ultrasonic frequency vibrations, transfer collision and impact energy to the cut medium, and cause fatigue and breakage of the cut medium material to achieve the purpose of cutting. Ultrasonic cutting can process carbon fiber, glass fiber, Kevlar fiber, various honeycomb composite materials and hard and brittle materials such as optical glass, silicon crystal, ceramics, etc. more effectively and accurately. In addition, since the cutting tool in contact with biological tissue can vaporize water in biological tissue, break protein hydrogen bonds, disintegrate cells, cut tissue, coagulate and seal small blood vessels when vibrating at a certain ultrasonic frequency, ultrasonic cutting technology can also be applied to medical surgical tools. At present, ultrasonic cutting technology has been widely used in medical, aerospace, chemical, agricultural, food and machinery fields.

[0003] In ultrasonic cutting processing, when other conditions remain unchanged, the larger the amplitude of the cutting tool, the higher the conversion efficiency of the ultrasonic piezoelectric transducer. Increasing the amplitude of the cutting tool can increase the speed of the cutting process. Therefore, in ultrasonic cutting processing, the amplitude of the sharp edge of the tool is one of the important indicators of the performance of the cutting tool. In order to improve the performance of ultrasonic vibration in various application fields, various methods have been adopted to increase the vibration amplitude of ultrasonic vibration. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcoming of low amplitude in the existing piezoelectric transducer and provide a large-amplitude ultrasonic vibration cutting device.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0006] A large-amplitude ultrasonic vibration cutting device, which includes: a piezoelectric transducer, a primary amplitude transformer, a secondary amplitude transformer, an elastic amplitude transformer, a cutter head and a high-frequency power supply. The piezoelectric transducer includes a bolt and a rear cover plate, a piezoelectric ceramic sheet, an electrode sheet and a primary amplitude transformer, which are sequentially sleeved on the bolt from back to front and connected and pressed together. The secondary amplitude transformer is fixed at the front end of the primary amplitude transformer, the elastic amplitude transformer is fixed at the front end of the secondary amplitude transformer, the cutter head is fixed at the front end of the elastic amplitude transformer, the electrode sheet is connected to the high-frequency power supply, and the high-frequency power supply can provide an ultrasonic electrical signal to the piezoelectric ceramic sheet through the electrode sheet, so that the piezoelectric ceramic sheet drives the entire piezoelectric transducer to generate axial vibration. The primary amplitude transformer, the secondary amplitude transformer and the elastic amplitude transformer gradually amplify the vibration amplitude of the piezoelectric transducer.

[0007] To optimize the above technical solutions, the specific measures taken also include:

[0008] The above-mentioned piezoelectric transducer is installed with a protective shell outside, and a flange is provided on the first-level amplitude rod, which is fixedly connected to the protective shell. The piezoelectric transducer is fixed in the protective shell through the flange, and the front end of the first-level amplitude rod extends from the protective shell and is connected to the second-level amplitude rod.

[0009] The above-mentioned blade edge has a sharp cutting edge, and the sharp cutting edge has a triangular sawtooth structure with the tip facing the tail end of the blade; arc transitions are provided at the cross-sectional mutation parts of the primary amplitude rod, the secondary amplitude rod, the elastic amplitude rod, the blade and the blade handle.

[0010] The elastic amplitude rod mentioned above is an "S"-shaped structure with a planar spring. In the "S"-shaped structure, its cross-sectional diameter is d, and the spacing of the rotation axes in the S shape is L, L∈(2d,∞).

[0011] The elastic coefficient of the elastic amplitude rod along the axial direction of the cutting device is K, and the axial vibration frequency of the large amplitude longitudinal vibration cutting device is f , the mass of the cutter head is M, the mass of the elastic amplitude rod is m, then the relationship is satisfied: .

[0012] The elastic amplitude transformer and the secondary amplitude transformer are an integrated structure.

[0013] The above-mentioned secondary horn is connected and arranged at the front end of the primary horn by means of screws.

[0014] The operating frequency range of the above-mentioned cutter head is 18kHz-80kHz.

[0015] The large-amplitude longitudinal vibration cutting device has only one set of longitudinal vibration piezoelectric ceramic plates.

[0016] The large-amplitude longitudinal vibration cutting device only needs one ultrasonic electrical signal excitation.

[0017] The present invention adopts a sandwich-type piezoelectric piezoelectric transducer and an elastic amplitude transformer structure, which can effectively improve the output power and amplitude ratio of the transducer. Under the condition of equal power, the vibration amplitude of the cutting knife can be effectively increased, and the electro-mechanical conversion efficiency can be improved. The large-amplitude longitudinal-bending ultrasonic vibration cutting device can be used for efficient cutting of carbon fiber, glass fiber, Kevlar fiber, various honeycomb composite materials, rubber and other materials, and has stable working performance and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 is a top view of the present invention;

[0020] Figure 3It is a schematic diagram of the structure of the cutter head of the present invention;

[0021] Figure 4 is a top view of the cutter head structure of the present invention;

[0022] Figure 5 It is a schematic structural diagram of the elastic horn of the present invention;

[0023] Figure 6 It is a schematic diagram of an application example of the present invention;

[0024] Explanation of the numbers in the figure: bolt 1, rear cover plate 2, piezoelectric ceramic sheet 3, electrode sheet 4, primary amplitude transformer 5, flange 6, housing 61, high-frequency power supply 62, secondary amplitude transformer 7, elastic amplitude transformer 8, cutter head 9, triangular sawtooth structure 91. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0026] like Figure 1-6 As shown, a large-amplitude ultrasonic vibration cutting device of the present embodiment includes a piezoelectric transducer, a primary amplitude transformer 5, a secondary amplitude transformer 7, an elastic amplitude transformer 8, a cutter head 9 and a high-frequency power supply 62. The piezoelectric transducer is a cylindrical body as a whole, including a bolt 1 and a rear cover plate 2, a piezoelectric ceramic sheet 3, an electrode sheet 4 and a primary amplitude transformer 5 which are sequentially sleeved on the bolt 1 from back to front and connected and pressed together. The secondary amplitude transformer 7 is fixed at the front end of the primary amplitude transformer 5, the elastic amplitude transformer 8 is fixed at the front end of the secondary amplitude transformer 7, the cutter head 9 is fixed at the front end of the elastic amplitude transformer 8, the electrode sheet 4 is connected to the high-frequency power supply 62 through a wire, and the high-frequency power supply 62 can provide an ultrasonic electrical signal to the piezoelectric ceramic sheet 3 through the electrode sheet 4, so that the piezoelectric ceramic sheet 3 drives the entire piezoelectric transducer to generate axial vibration, and the primary amplitude transformer 5, the secondary amplitude transformer 7 and the elastic amplitude transformer 8 gradually amplify the vibration amplitude of the piezoelectric transducer. The piezoelectric transducer has only one set of longitudinal vibration piezoelectric ceramic pieces 3, the diameter of the piezoelectric ceramic transducer section is 30 mm, the piezoelectric ceramic piece 3 is PZT-8, and the size is: Ф30×Ф15×5 , the number of piezoelectric ceramic sheets 3 is 2.

[0027] The natural frequency of the piezoelectric transducer is 29.86KHz, the impedance is 63 ohms, the dynamic resistance is 19 ohms, the output voltage range of the high-frequency power supply 62 is 0-400V, the current range is 0-4A, the output frequency is 29.86±0.01KHz, and the high-frequency power supply 62 has an automatic frequency tracking function within the specified frequency range.

[0028] The elastic horn 8 is an "S" type structure with a planar spring, in which the cross-sectional diameter d is 6 mm, L is 4d=24 mm, and the spacing of the rotation axis in the S shape is L, L∈(2d,∞). The natural frequency coefficient of the elastic horn 8 is 29.88 kHz.

[0029] In the embodiment, a protective shell 61 is installed outside the piezoelectric transducer, a flange 6 is provided on the first-stage amplitude rod 5, the flange 6 is fixedly connected to the protective shell 61, the piezoelectric transducer is fixed in the protective shell 61 through the flange 6, and the front end of the first-stage amplitude rod 5 extends from the protective shell 61 and is connected to the second-stage amplitude rod 7.

[0030] In the embodiment, the edge of the cutter head 9 has a sharp cutting edge, and the sharp cutting edge has a triangular serrated structure 91 with the tip pointing toward the tail end of the cutter head 9; arc transitions are provided at the cross-sectional mutation sites of the primary amplitude variable rod 5, the secondary amplitude variable rod 7, the elastic amplitude variable rod 8, the cutter head 9 and the handle of the cutter head 9.

[0031] In the embodiment, the elastic coefficient of the elastic amplitude transformer 8 along the axial direction of the cutting device is K, and the axial vibration frequency of the large amplitude longitudinal vibration cutting device is f , the mass of the cutter head 9 is M, and the mass of the elastic amplitude rod 8 is m, then the relationship is satisfied: .

[0032] In the embodiment, the elastic amplitude transformer 8 and the secondary amplitude transformer 7 are an integrated structure.

[0033] In the embodiment, the secondary horn 7 is connected to the front end of the primary horn 5 by screws.

[0034] In the embodiment, the operating frequency range of the cutter head 9 is 18 kHz-80 kHz.

[0035] During operation, after the electrode sheet 4 of the piezoelectric transducer is connected to the electrical signal output by the high-frequency power supply 62, the piezoelectric ceramic sheet 3 will generate longitudinal ultrasonic vibration due to the inverse piezoelectric effect of the piezoelectric ceramic sheet 3, that is, the piezoelectric transducer converts the electrical energy output by the high-frequency power supply 62 into ultrasonic vibration energy, and drives the entire transducer system to perform longitudinal ultrasonic vibration. When the ultrasonic vibration energy is transmitted from the piezoelectric transducer to the end of the primary amplitude transformer 5, the original amplitude generated by the piezoelectric ceramic is amplified at the end of the primary amplitude transformer 5, and the ultrasonic vibration energy continues to be transmitted forward to the end of the secondary amplitude transformer 7, and the amplitude is amplified again. Finally, the ultrasonic vibration energy continues to be transmitted forward to the end of the elastic amplitude transformer 8, and the amplitude is amplified again. The longitudinal vibration at the end of the elastic amplitude transformer 8 is transmitted to the cutter head 9, and finally drives the cutter head 9 to perform longitudinal ultrasonic vibration.

[0036] When the piezoelectric transducer is loaded with voltage and runs for 10 minutes to reach a stable vibration state, the output voltage of the high-frequency power supply 62 is 220V, the current is 1.35A, and the amplitude of the end of the elastic horn 8 is 163 microns and the amplitude of the end of the cutter head 9 is 286 microns measured by a laser Doppler vibrometer. The conventional vibration amplitude is 8-20 microns, and the vibration amplitude of the large-amplitude longitudinal bending ultrasonic vibration cutting device is increased by 6-30 times. The cutting knife is held to cut a 2CM thick paper honeycomb composite material. When a cutting force of about 1N is applied, the cutting speed can reach 20mm / s, and no burrs are generated on the cutting edge of the composite material.

[0037] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A large-amplitude ultrasonic vibration cutting device, characterized in that: The invention comprises a piezoelectric transducer, a primary horn (5), a secondary horn (7), an elastic horn (8), a cutter head (9) and a high-frequency power supply (62), wherein the piezoelectric transducer comprises a bolt (1) and a rear cover plate (2), a piezoelectric ceramic sheet (3), an electrode sheet (4) and a primary horn (5) which are sequentially sleeved on the bolt (1) from back to front and connected and pressed together, the secondary horn (7) is fixed to the front end of the primary horn (5), and the elastic horn (8) is fixed to the front end of the primary horn (5). At the front end of the secondary amplitude transformer (7), a cutter head (9) is fixed to the front end of the elastic amplitude transformer (8), the electrode sheet (4) is connected to a high-frequency power supply (62), and the high-frequency power supply (62) can provide an ultrasonic electric signal to the piezoelectric ceramic sheet (3) through the electrode sheet (4), so that the piezoelectric ceramic sheet (3) drives the entire piezoelectric transducer to generate axial vibration, and the primary amplitude transformer (5), the secondary amplitude transformer (7) and the elastic amplitude transformer (8) gradually amplify the vibration amplitude of the piezoelectric transducer; The elastic amplitude change rod (8) is an "S"-shaped structure with a plane spring. In the "S"-shaped structure, its cross-sectional diameter is d, and the spacing of the rotation axes in the S shape is L, L∈(2d,∞).

2. The large-amplitude ultrasonic vibration cutting device according to claim 1, characterized in that: The piezoelectric transducer is provided with a protective shell (61) outside, the primary horn (5) is provided with a flange (6), the flange (6) is fixedly connected to the protective shell (61), the piezoelectric transducer is fixed in the protective shell (61) through the flange (6), and the front end of the primary horn (5) extends from the protective shell (61) and is connected to the secondary horn (7).

3. The large-amplitude ultrasonic vibration cutting device according to claim 2, characterized in that: The edge of the cutter head (9) has a sharp cutting edge, and the sharp cutting edge has a triangular sawtooth structure (91) with the tip pointing toward the tail end of the cutter head (9); arc transitions are provided at the cross-sectional mutation sites of the primary amplitude change rod (5), the secondary amplitude change rod (7), the elastic amplitude change rod (8), the cutter head (9) and the handle of the cutter head (9).

4. A large-amplitude ultrasonic vibration cutting device according to claim 3, characterized in that: The elastic coefficient of the elastic amplitude change rod (8) along the axial direction of the cutting device is K, the axial vibration frequency of the large-amplitude longitudinal vibration cutting device is f, the mass of the cutter head (9) is M, and the mass of the elastic amplitude change rod (8) is m, then the relationship is satisfied:

5. A large-amplitude ultrasonic vibration cutting device according to claim 4, characterized in that: The elastic amplitude changing rod (8) and the secondary amplitude changing rod (7) are an integrated structure.

6. A large-amplitude ultrasonic vibration cutting device according to claim 5, characterized in that: The secondary horn (7) is arranged at the front end of the primary horn (5) by means of screw connection.

7. A large-amplitude ultrasonic vibration cutting device according to claim 6, characterized in that: The operating frequency range of the cutter head (9) is 18kHz-80kHz.

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