Partition plate securement for an ultrasonic flow meter
An ultrasonic flow rate measuring device includes a flow path, a partition plate that is inserted from an aperture to partition the flow path into plural sections, an ultrasound transmission body, plural ultrasonic transducers that are provided in positions facing a bottom plate such that an ultrasonic wave transmitted from one of the ultrasonic transducers through the ultrasound transmission body is reflected by the bottom plate and received by the other ultrasonic transducer, a measurement circuit that measures an ultrasonic propagation time between the plurality of the ultrasonic transducers; and a calculation circuit that obtains a flow rate of the target fluid based on a signal from the measurement circuit.
1. An ultrasonic flow rate measuring device comprising:
a flow path in which a target fluid flows, the flow path including a first sidewall that is provided along a flow direction of the target fluid, a second sidewall that is disposed facing the first sidewall, a bottom plate that extends from a bottom of the first sidewall to a bottom of the second sidewall, an upper wall unit that connects an upper portion of the first sidewall and an upper portion of the second sidewall, and one aperture that is provided in the upper wall unit facing the bottom plate;
a partition plate that is inserted from the aperture to partition the flow path into a plurality of sections;
an ultrasound transmission body that covers the aperture;
a plurality of ultrasonic transducers that are provided in positions facing the bottom plate such that an ultrasonic wave transmitted from one of the ultrasonic transducers through the ultrasound transmission body is reflected by the bottom plate and received by the other ultrasonic transducer;
a measurement circuit that measures an ultrasonic propagation time between the plurality of the ultrasonic transducers; and
a calculation circuit that obtains a flow rate of the target fluid based on a signal from the measurement circuit,
wherein the partition plate includes upper protrusions formed only at both side ends in an upper portion of the partition plate, and lower protrusions formed in plural positions at a lower end of the partition plate,
first insertion grooves, in which the upper protrusions are inserted, are provided at the both sides of the aperture in the flow path direction, and
second insertion grooves, in which the lower protrusions are inserted, are provided in the bottom plate.
2. The ultrasonic flow rate measuring device according to claim 1 , wherein each of the insertion grooves of the bottom plate is provided in a position different from a reflection position of the ultrasonic wave in the bottom plate.
3. The ultrasonic flow rate measuring device according to claim 1 , wherein an upper portion of the insertion groove of the bottom plate is greater than a width of the protrusion and a lower portion of the insertion groove is less than the width of the protrusion.
4. The ultrasonic flow rate measuring device according to claim 1 comprising a plurality of abutment units that protrude from inner surfaces of the insertion groove of the bottom plate, the abutment units being located so as not to face each other, wherein the partition plate is abutted on and held by the abutment units.
5. The ultrasonic flow rate measuring device according to claim 1 , wherein an entrance wall surface of the flow path in which the target fluid flows is a curved surface.