02-4 东莞思威特电子-压电水声换能器的应用.doc

思威特电子-压电换能器在声纳系统中应用Sonar for detection 声纳，是英语“声导航和定位”的缩写利用水下声波的传播的规律进行水中目标的观察和通讯的系统成为声纳系统声纳系统应在民用方面有测深仪器、多波束深仪器，海底底层剖面仪和多普勒导航声纳等，在军事上，舰用主动、被动声纳，拖拽可变深度声纳、拖拽线列声纳、直升飞机吊放声纳、定位、跟踪、浮标声纳等等压电声纳在两次世界大战和民用方面，发挥了重要作用Sonar is short for “Sound Navigation And Ranging”. The system that utilizes the propagating laws of underwater sound wave to observe and communicate the target in water defines as sonar system. For civil use, it covers sounding apparatus, multi-beam deep instrument, ocean bottom profiler and Doppler navigation sonar etc. For military use, it covers active and passive sonar used in warship, towed variable-depth sonar, towed array-liner sonar, helicopter-dunked sonar, fixed sonar, tracking sonar and sonobuoy etc.最早使用于鱼群探测仪的郎之万型换能器，是外径为60 mm,，厚度为5mm的压电陶瓷片与厚度为14 mm的两个钢柱粘结而成的，重量约为700克，谐振频率为50KHz。

当把它作为发射、接收换能器使用时，其实际结构图如图2所示它是用橡胶把换能器与电缆包封起来声波通过厚度约为1cm的透声橡胶向水中辐射信号（橡胶一起的损失仅为1dB，影响可以忽略）;辐射面以外的换能器部分均用海绵橡胶包封，使声波仅向一个方向辐射Langevin transducer consists of piezoelectric ceramic that is 60 mm in diameter and 5 mm in thickness and two steel columns that is 14 mm in thickness, it is 700 gram in weight and 50 KHz in resonant frequency, which is firstly used to fish detector. As shown in Fig.2, it is an actual structural drawing when used as transmitting and receiving transducer. The rubber seals transducer and cable up. The sound wave radiates signal to water via a perforated rubber in 1 cm thickness. (It only loses 1 dB with the rubber, so the influence is negligible.) The transducer beyond the radiating surface is used foamed rubber to seal up, which makes sound wave radiate to one direction. 郎之万型换能器在大功率振动状态下，易产生压电陶瓷片振裂现象；图3是复合棒形换能器的结构示意图。

预应力螺杆使压电陶瓷片与前后盖板之间除了粘结外还紧紧地压紧，使其能承受更大的张压力，改善在大功率工作状态下陶瓷片损坏和脱胶现象复合棒形换能器将前盖取为带锥度的轻金属，使换能器与水介质有更好的阻抗匹配，并增大辐射面积；后盖板采用带锥度的重金属，使尾部的声辐射变得很小，形成较好的自然单面辐射振子 Langevin transducer easily affects piezoelectric ceramic’s vibration crack once it is vibrating with high power. Fig.3 is the structure diagram of compound bar transducer. Prestressed screw compresses piezoelectric ceramic with front and back cover tightly besides cementation; it can bear stronger pressure, which improves piezoelectric ceramic’s damage and degumming in high power. The front cover is made of light metal with taper, which better matches the transducer and aqueous medium in impedance and increases radiating area. The back cover is made of heavy metal with taper, which decreases sound radiation of the empennage and forms a well natural single-side radiation oscillator.。