Patent ID: 9671264
Date: 2017-06-06
CPC Classifications: G01F

Claim:
1. An ultrasonic flow switch to output an ON/OFF signal based on a flow rate of a fluid in a pipe, the ultrasonic flow switch comprising: a first ultrasonic wave element configured to transmit an ultrasonic wave to a fluid in a pipe; a second ultrasonic wave element configured to receive the ultrasonic wave from the fluid in the pipe; a calculator configured to calculate a flow rate of the fluid in the pipe based on an output signal from the second ultrasonic wave element; an output part configured to output the ON/OFF signal based on the flow rate calculated by the calculator and a preset flow rate threshold value; an element holder integrally or independently holding the first ultrasonic wave element and the second ultrasonic wave element; a mounting member detachably mounted on an outer surface of the pipe, configured to hold the element holder; and an acoustic contact medium formed of a soft elastic body, and arranged between at least one of the first and second ultrasonic wave elements and the pipe, wherein the acoustic contact medium is pressed to the outer surface of the pipe such that the at least one ultrasonic wave element is acoustically coupled to the pipe in a state where the mounting member is mounted on the outer surface of the pipe and the element holder is held by the mounting member, and the ultrasonic flow switch further comprises a collapsing amount restricting part which restricts a collapsing amount of the acoustic contact medium at a portion where the collapsing amount of the acoustic contact medium caused by the pipe is the largest.