1 楔形超声切割刀的等效电路与共振频率方程
2 振动性能
2.1 楔形切割刀的振动性能
表1 不同材料和长度楔形超声切割刀纵振动谐振频率与位移放大系数Tab.1 Longitudinal vibration resonance frequency and displacement amplification factor of wedge ultrasonic cutting tools with different materials and lengths |
| 编号(材料) | H/mm | L/mm | r/mm | ft/kHz | fe/kHz | Δ/% | Mt | Me |
|---|---|---|---|---|---|---|---|---|
| 1#(45#钢) | 25 | 35 | 70 | 43.98 | 42.58 | 3.3 | 2.479 | 2.345 |
| 2#(45#钢) | 25 | 35 | 80 | 38.48 | 37.57 | 2.4 | 2.481 | 2.394 |
| 3#(45#钢) | 25 | 35 | 87 | 35.38 | 34.69 | 2.0 | 2.482 | 2.410 |
| 4#(45#钢) | 25 | 35 | 90 | 34.20 | 33.59 | 1.8 | 2.483 | 2.417 |
| 5#(铝) | 25 | 35 | 90 | 34.50 | 33.80 | 1.0 | 2.482 | 2.408 |
| 6#(钛合金) | 25 | 35 | 90 | 31.24 | 30.61 | 1.0 | 2.482 | 2.408 |
2.2 带有激励源的超声切割刀的振动性能
表2 带激励源楔形超声切割刀的几何尺寸及材料参数Tab.2 Geometric dimensions and material parameters of wedge ultrasonic cutting tool with excitation source |
| 名称 | 纵向尺寸/ mm | 横向尺寸/ mm | 杨氏模量/ Pa | 密度/ (kg·m-3) | 压电系数d33/ (C·N-1) | 应变系数 / (m2·N-1) | 介电常数 / (F·m-1) | k33 |
|---|---|---|---|---|---|---|---|---|
| 螺栓 | 6 | 4 | 1.93×1011 | 7 930 | ||||
| 后盖 | 9 | 8 | 1.93×1011 | 7 930 | ||||
| 压电晶堆 | 4×2.6 | 8 | 7 700 | 2.25×10-10 | 1.35×10-11 | 1.044 3×10-8 | 0.6 | |
| 楔形切割刀 | 87 | 34.2×24 | 1.93×1011 | 7 930 |
3 实验测试
表3 谐振频率、位移放大系数及有效机电耦合系数理论计算值与实验测量值Tab.3 Resonant frequency, displacement amplification factor and effective electromechanical coupling coefficient theoretical calculation value and experimental measurement value |
| fts/kHz | fes/kHz | ftms/kHz | Δ1/% | Δ2/% | Mt | Me | Mtm | Kefft | Keffe | Kefftm |
|---|---|---|---|---|---|---|---|---|---|---|
| 30.82 | 29.90 | 29.55 | 4.30 | 1.19 | 2.692 | 2.786 | 2.786 | 0.34 | 0.22 | 0.29 |