| 摘要 |
<p>PURPOSE: To improve the service life of a converter by arranging an attenuation layer having different acoustic impedance between shell bodies of a support comprising a metallic outer shell body and a metallic inner shell body to reduce the load on an ultrasonic converter in a bore of a shock wave source. CONSTITUTION: A receiving part of an ultrasonic converter 12 comprises two shell bodies 14, 16, and an attenuation medium 18 is interposed therebetween. The inner shell body 14 and the outer shell body 16 are made of the metal having large differential impedance from water. The attenuation medium 18 is provided with a gas-containing filling material, or consists of a synthetic resin, rubber or silicone rubber. While the shock wave reaches the ultrasonic converter 12, four boundary surfaces are generated in the medium whose acoustic impedance is largely different. At these four boundary surfaces, the shock wave performs the local reflection, and the shock wave component to be applied to the ultrasonic converter 12 is remarkably weakened as a whole. Thus, the service life of the converter can be improved.</p> |
