JPH11325992A5 - - Google Patents

Claims (7)

An ultrasonic flow measurement device in which an ultrasonic vibrator is attached to a mounting hole provided in a wall of a fluid passage through which a fluid to be measured flows, the ultrasonic vibrator comprising: a topped cylindrical case having a top portion , a side wall portion , and an opening; a piezoelectric body fixed to the inner wall surface of the top portion ; an acoustic matching layer provided on the outer wall surface of the top portion; a flange provided on the end of the side wall portion; and a support formed by overlapping the flange and a sealing body that closes the opening, wherein the support portion of the ultrasonic vibrator is attached to the mounting hole via a vibration transmission inhibitor that reduces the vibration of the ultrasonic vibrator from being transmitted to the fluid passage wall side . 2. The ultrasonic flowmeter according to claim 1, wherein the thickness of the sealing body of the support portion is greater than that of the flange. 3. The ultrasonic flow rate measuring device according to claim 2 , wherein the vibration transmission suppressor is provided with a protrusion at least on the side of the fluid passage wall, so that the vibration transmission suppressor and the fluid passage wall are in partial contact with each other. 4. An ultrasonic flow rate measuring device according to claim 2 , wherein the vibration transmission inhibitor is made of an elastic body, and a deformation preventive body for preventing deformation of the elastic body is provided in contact with the vibration transmission inhibitor. 5. The ultrasonic flowmeter according to claim 4 , wherein the deformation preventive body is made of a material having an acoustic impedance smaller than that of at least the case or the sealing body that closes the opening of the case. 6. An ultrasonic flow measurement device according to claim 1, wherein the mounting hole is a stepped mounting hole provided with a step portion that serves as a contact point for the vibration transmission inhibitor, the vibration transmission inhibitor with the ultrasonic vibrator attached is inserted into this stepped mounting hole, and the vibration transmission inhibitor is fixed by a fixing body provided outside the stepped mounting hole, so that the ultrasonic vibrator is not in contact with the fluid passage wall or the fixing body. 7. The ultrasonic flow rate measuring device according to claim 1 , wherein the opening of the mounting hole to the fluid passage has a cross-sectional area smaller than that of the housing portion that houses the side wall portion of the ultrasonic vibrator.