共查询到18条相似文献,搜索用时 62 毫秒
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超声技术的基石——超声换能器的原理及设计 总被引:9,自引:0,他引:9
超声换能器是在超声频率范围内将交变的电信号转换成声信号或者将外界声场中的声信号转换为电信号的能量转换器件,它是超声技术中的关键器件,其性能好坏直接关系到超声应用技术的效果和使用范围.由于超声技术的应用范围很广,且超声新技术层出不穷,因而与此对应的超声换能器的种类也很多.文章对不同应用背景下多种类型超声换能器的原理及设计进行了阐述,分析了不同类型超声换能器的性能参数及设计要求,简要总结了超声换能器的性能参数测试方法,并对超声换能器的发展趋势进行了一定的分析. 相似文献
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为使功率超声设备工作稳定,许多场合要求换能器输出到负载的机械功率与负载大小成比例.而换能器注入负载的功率可用三个参量来描述,即力、振速及其工作端面的机械振动功率.如能稳定振动速度,即可实现稳定的要求.文中讨论了稳定振速的方法,并给出一例用光耦合器反馈振速信号的振速自动稳定电路. 相似文献
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超声换能器表面的振动状态 总被引:2,自引:1,他引:1
从超声波在波密介质和波疏介质之间的传播以及诱发共振发射超声波的角度,讨论了空气中超声声速测量实验所用超声换能器的表面振动状态.理论分析及实验测量结果表明:超声换能器表面振动状态与其结构有关,超声接收器表面位移振幅一般不为零. 相似文献
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超声内镜集结了超声检查与内镜检查双重功能,可以获得腹部和胸腔内器官的高质量图像,是一种先进的医疗设备。超声内镜探头的核心部分是超声换能器。超声内镜检查需经过狭窄的消化道或内窥镜的活检通道伸进体内,由于工作环境的限制,超声内镜用换能器与普通超声成像换能器相比,工作频率更高、尺寸更小、制作工艺更精密。本文从超声内镜所用换能器的外形结构、内部组成、工作模式及材料等角度,对目前国内外超声内镜换能器的应用进展情况进行了描述,并根据超声内镜换能器的现状对未来的发展趋势进行了分析。 相似文献
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由第七一五所教授级高级工程师俞宏沛撰写的《超声组件的计算机辅助设计》小册已于1991年10月在内部发行。 作者俞宏沛同志长期从事换能器的研究与设计工作,在功率超声方面具有丰富的实践经验。他很早就在换能器设计中采用了计算机辅助设计方法,并取得显著成效。该小册5万多字,是俞宏沛同志多年从事功率超声振动组件(换能器、变幅杆和工具头)计算机辅助设计的经验总结。小册中部分内容曾在功率超声 相似文献
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Shuyu L 《Ultrasonics》2005,43(5):365-373
Based on the equivalent circuit theory, the load characteristics of high power piezoelectric ultrasonic sandwich transducers are studied. Two types of loads are studied. One is liquid load as in ultrasonic cleaning, and the other is solid load as in ultrasonic drilling and machining. The effect of load and structure of the transducer on the resonance frequency of the transducer is analyzed. It is shown that the effect of load on the resonance frequency of sandwich transducers with different structures is different. For liquid load as in ultrasonic cleaning, the effect of the load on the resonance frequency of the sandwich transducer with symmetrical structure is the largest. It is the smallest for the transducer with its displacement node in the back metal cylinder. For solid load as in ultrasonic drilling and machining, the effect of the load on the resonance frequency of the sandwich transducer with its displacement node in the front metal cylinder is the largest. It is also the smallest for the transducer with its displacement node in the back metal cylinder. On the other hand, for some applications, such as ultrasonic drilling, when the lateral dimension of the tool is much less than that of the transducer, its effect on the resonance frequency of the transducer is small. The conclusions are useful in designing vibrating systems for different ultrasonic applications. 相似文献
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An absolute methodology has been developed for quantification of misalignment of an ultrasonic transducer using a corner-cube retroreflector. The amplitude based and the time of flight (TOF) based C-scans of the reflector are obtained for various misalignments of the transducer. At zero degree orientation of the transducer, the vertical positions of the maximum amplitude and the minimum TOF in the C-scan coincide. At any other orientation of the transducer with the horizontal plane, there is a vertical shift in the position of the maximum amplitude with respect to the minimum TOF. The position of the minimum (TOF) remains the same irrespective of the orientation of the transducer and hence is used as a reference for any misalignment of the transducer. With the measurement of the vertical shift and the horizontal distance between the transducer and the vertex of the reflector, the misalignment of the transducer is quantified. Based on the methodology developed in the present study, retroreflectors are placed in the Indian 500 MWe Prototype Fast Breeder Reactor for assessment of the orientation of the ultrasonic transducer prior to the under-sodium ultrasonic scanning for detection of any protrusion of the subassemblies. 相似文献
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对超声波换能器频率测试系统进行了探讨,并在此基础上提出了改装设想,分析了所研究的简易超声波换能器频率测试仪的电路原理及实验结果。 相似文献
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多匹配层空气耦合压电超声换能器* 总被引:1,自引:0,他引:1
该文针对超声无损检测与成像功能空气耦合换能器开展了分析计算和研制。为解决压电材料与空气间巨大的阻抗失配问题,进行了多匹配层设计,并基于有限元技术仿真设计了1-3压电复合材料参数。借助复数压电方程,导出考虑损耗的多匹配层压电复合材料换能器厚度振动等效电路,获得其等效导纳,以此计算电导谱,同时基于有限元技术数值计算相应电导谱,二者有较好的一致性。在此基础上分别设计制作复合压电材料,多匹配层材料以及由此构成的空气耦合超声换能器。换能器的实测电导谱与数值仿真结果一致。进一步的换能器回波信号测试及其谱分析结果表明,所研制的160 k Hz中心频率空气耦合换能器样品有较好灵敏度和带宽。这些结果说明,该文研制的空气耦合超声换能器的初样是成功的。 相似文献
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MEMS(micro-electromechanical systems)超声换能器(MEMS ultrasonic transducer,简称MUT)是采用微电子和微机械加工技术制作的新型超声换能器。与传统超声换能器相比,MUT具有体积小、重量轻、成本低、功耗低、可靠性高、频率控制灵活、频带宽、灵敏度高以及易于与电路集成和实现智能化等特点。是超声换能器的重要的研究方向之一。MUT的研究主要包括压电MUT(piezoelectric MUT,简称PMUT)和电容MUT(capacitiveMUT,简称CMUT)两个方面。本文概述了PMUT研究的发展进程和研究成果,展望了PMUT的研究和应用前景。 相似文献