Nozzle Processing Using Ultrasonic Cavitation Jet

在高强度超声的作用下，会产生空化和递进流。将其应用于小型汽油机燃油喷嘴的精加工是一项研究。与传统方法相比，预期效果更好。结果几乎消除了小于10微米的钻削毛刺，增加了流量。形状改变了比它大的毛刺，但不可能去除。根据这些结果，我们考察了有效空化能的使用。一是阐明了超声空化的产生机理。今年做了这个研究。实验装置：超声振子增加指数喇叭进行振幅扩展，用于发射高强度空化。振动器以28khz 150W的频率驱动它。一种实验装置，具有通过空化作用排出多余气泡的结构。空化的排放介质采用高脱氧城市水。观察水箱采用透明亚克力管制作。在声场节点处对气泡进行圈闭是一种结构。我成长了一代又一代，泡沫终于有了一个破灭的过程。我们观察到气泡形状随空化强度和崩塌时刻声压的变化。空化气泡的观察气泡的直径很小，有微米级。气泡的产生是不规则的，运动是激烈的。我们用高速CCD显微镜观察了这个空化气泡。放大率最高可达800倍。摄影区域很小，很难观察一秒钟的现象。一些观察经过多次试验获得了成功。此外，还观察到了空化泡坍缩时的声发光现象。

There is abrasion action for cavitation and progressing flow to occur by a high-intensity ultrasonic. It is a study to use this for the finish processing of the fuel jet nozzle for small gasoline engines. In comparison with a conventional method, superior action is expected. As a result, burr of drill processing equal to or less than,10 micron was almost removed, and flow quantity increased. Shape transformed the large burr than it, but the removal was not possible. From these results, we examined usage of effective cavitation energy. The one is elucidation of processing mechanism of ultrasonic cavitation. This year did this study.An experimental deviceThe ultrasonic vibrator added exponential horn for amplitude expansion to used it for emission of the cavitation which was high-intensity. The vibrator drove it at 28 kHz 150W. An experimental device has structure to drain an unnecessary bubble by cavitation. The emission medium of cavitation used high deaerated city water. The observation water tank was made with a transparent acrylic pipe. It is structure to do a trap of a bubble in node of acoustic field. I grow up after generation, and a bubble takes a collapsing process at last. We observe a change of shape of a bubble for cavitation intensity and sound pressure of a moment of collapse.Observation of a cavitation bubbleA diameter of a bubble is small with micron order. Generation of a bubble is irregular, and the movement is intense. We observed this cavitation bubble with a high speed CCD microscope. Magnification at the maximum is 800. It was difficult that a photography area was small observation a phenomenon for a second. Some observation succeeded by many trials. Furthermore, acoustic luminescence with collapse of a cavitation bubble was observed.