JP2004226334A - Ultrasonic flowmeter sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the use of the conventional ultrasonic flowmeter allows the reception of the ultrasonic wave propagated through a pipe 1 by a second ultrasonic vibrator 5 to make undistinguishable between the ultrasonic wave reflected by the wall surface of the pipe 1 and that received by propagation through the pipe 1, and to make no accurate measurement when the ultrasonic wave is radiated from a first ultrasonic vibrator 4 because the first and second ultrasonic vibrators 4 and 5 are respectively fitted to the attaching sections 2 and 3 of the pipe 1 in their contacting states. <P>SOLUTION: An ultrasonic flowmeter sensor is divided into an upper cylindrical section 6, a cap member 7, and a lower cylindrical section 8. The upper cylindrical section 6 has a flange 6a having a screw thread 6b formed inside the flange 6a. A cap section 7d is engaged with the cap member 7 and a piezoelectric ceramic 9 is fitted to the lower end of the lower cylindrical section 8 and an irradiation plate 8a is fitted to the ceramic 9. A first cylindrical section 8b is stuck to the irradiation plate 8a and the upper end of the first cylindrical section 8b is stuck to a second cylindrical section 8c. In addition, the projecting section 8d of the second cylindrical section 8c is engaged with the flange 6a of the upper cylindrical section 6. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ultrasonic washing flowmeter sensor provided with a pressure-resistant and explosion-proof structure.
[0002]
[Prior art]
In general, as shown in FIG. 3, the ultrasonic flow meter has a liquid for measuring a flow rate flowing through a pipe 1 and first and second mounting portions 2 and 3 formed on the pipe 1 at a predetermined angle. When two ultrasonic vibrators 4 and 5 are mounted and ultrasonic waves are emitted from the first ultrasonic vibrator 4 along the flow of the liquid, the ultrasonic waves reflected on the wall of the pipe 1 become the second ultrasonic vibrators. When the ultrasonic wave is received by the ultrasonic vibrator 5 and the time is measured, and the ultrasonic wave is irradiated from the second ultrasonic vibrator 5 against the flow, the ultrasonic wave reflected on the wall of the pipe 1 The time is received by the first ultrasonic transducer 4 and the time is measured, so that the flow rate of the liquid is measured from the difference between the propagation time of the ultrasonic wave along the flow of the liquid and the propagation time of the ultrasonic wave against the flow of the liquid. It is configured to be.
[0003]
[Problems to be solved by the invention]
However, in such an ultrasonic flowmeter, the first and second ultrasonic vibrators 4 and 5 are fitted to the mounting portions 2 and 3 of the pipe 1, and the first and second ultrasonic vibrators 4 and 5 are attached to the mounting portions 2 and 3 respectively. When the ultrasonic oscillators 4 and 5 are in contact with each other, the ultrasonic waves propagating through the pipe 1 are received by the second ultrasonic oscillator 5 when the ultrasonic waves are emitted from the first ultrasonic oscillator 4. As a result, there is a problem that the ultrasonic wave reflected on the wall surface of the pipe 1 and the ultrasonic wave transmitted through the pipe 1 cannot be distinguished, and accurate measurement cannot be performed.
[0004]
[Means to solve the problem]
The present invention relates to an upper cylinder having a flange protruding outward at a lower end, a screw thread provided inside, and an internal holding portion formed at a slight interval above the flange to form an internal holding portion, and a screw thread formed at an upper inside. And a thread engaging with a thread inside the upper end of the upper cylindrical portion is engaged with a thread formed on the lower projection, and an upper projection is formed from a center hole of the lower projection, Upper end of a first cylindrical portion to which a lid member provided with a screw portion provided with a screw thread which engages with a screw thread formed outside the upper end of the protruding portion, and an ultrasonic irradiation plate mounted with piezoelectric ceramics are fixed to an end portion. A lower cylindrical portion having a second cylindrical portion fixed thereto, a projecting portion projecting outward at an upper end of the second cylindrical portion, and a thread formed at an end of the projecting portion. A thread outside the protrusion of the second cylindrical portion of the cylindrical portion is engaged with a thread at the lower end of the upper cylindrical portion. The upper cylindrical portion and the lower cylindrical portion are filled with a resin, and the irradiation plate is fixed to a lower end of a first cylindrical portion of the lower cylindrical portion and the first cylindrical portion is fixed to the lower cylindrical portion. The fixing between the upper end of the portion and the lower end of the second cylindrical portion is welded by electron beam welding, and furthermore, the inner protruding portion of the upper cylindrical portion and the second cylindrical portion of the lower cylindrical portion are bonded together. A resin sheet is interposed between the projecting portions, and the upper cylindrical portion, the lower cylindrical portion, and the lid member are made of stainless steel.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to an ultrasonic wave from a piezoelectric ceramic mounted inside a lower cylindrical portion when a flange of the upper cylindrical portion is mounted on a pipe mounting portion by connecting an upper cylindrical portion and a lower cylindrical portion with a screw. Is reflected at the screw coupling portion so as not to leak from the flange of the upper cylindrical portion to the pipe, and the lower cylindrical portion is divided into the first and second cylindrical portions and the irradiation plate on which the piezoelectric ceramic is mounted, The ultrasonic waves leak from the flange of the upper cylindrical portion to the pipe by electron beam welding, and by reducing the ultrasonic waves propagating from the irradiation plate to the second cylindrical portion via the first cylindrical portion. It is configured so that there is no flow rate and the flow rate measurement is accurate.
[0006]
【Example】
FIG. 1 is a cross-sectional view of an ultrasonic flowmeter sensor according to an embodiment of the present invention. FIG. 2 is a side view of the ultrasonic flowmeter sensor of FIG. 1. The flowmeter sensor includes an upper cylindrical portion 6, a cover member 7, and a lower cylindrical portion. A flange 6a is formed at the lower end of the upper cylindrical portion 6, and a thread 6b is formed inside the flange 6a. Further, the thread 6b is formed slightly apart from the thread 6a. A projecting portion 6c is formed, and a thread 6d is formed inside the upper end of the upper cylindrical portion 6, and the thread 6d is formed at the end of the projecting portion 7b provided at the lower end of the lid cylindrical portion 7a of the lid member 7. The formed thread 7c is engaged, a thread 7d is formed outside the upper end of the lid cylindrical portion 7a, and the thread 7f of the lid 7e is engaged with the thread 7d. A piezoelectric ceramic 9 is mounted on the irradiation plate 8a at the lower end, and the periphery of the irradiation plate 8a is a first cylinder. 8b, the upper end of the first cylindrical portion 8b is fixed to the second cylindrical portion 8c, and the upper end of the second cylindrical portion 8c is formed with a protruding portion 8d protruding outward. A thread 8e is formed outside the portion 8d, and the thread 8e is engaged with the thread 6b inside the flange 6a at the lower end of the upper cylindrical portion to be integrally formed.
[0007]
The resin sheet 10 is interposed between the protruding portion 6c inside the upper cylindrical portion 6 and the protruding portion 8d of the second cylindrical portion 8c of the lower cylindrical portion 8, and the upper cylindrical portion 6, the lid member 7, and the lower cylindrical portion 8, the resin 11 is filled, the lead wire 9a of the piezoelectric ceramic 9 is drawn out from the central portion of the cover 7e of the cover member 7, and the lead wire 9a drawn from the cover 7e is configured as a cable 9b. Further, the irradiation plate 8a of the lower cylindrical portion 8, the lower end of the first cylindrical portion 8b, the upper end of the first cylindrical portion 8b, and the lower end of the second cylindrical portion 8c are welded by electron beam welding.
[0008]
In this embodiment, because of this configuration, the amount of the ultrasonic wave emitted from the piezoelectric ceramics 9 leaking from the periphery of the irradiation plate 8a to the first cylindrical portion 8b is small, and the first cylindrical portion 8b From the second cylindrical portion 8c to the second cylindrical portion 8c, and the threads 6b and 8d are formed between the second cylindrical portion 8c and the upper cylindrical portion 6. The ultrasonic waves do not leak to the cylindrical portion 6, and therefore the ultrasonic waves are not propagated from the flange 6a of the upper cylindrical portion 6 to the pipe 1 shown in FIG. 3, so that accurate measurement can be performed.
[0009]
【The invention's effect】
As described above, the ultrasonic flowmeter sensor of the present invention is configured such that, when the upper cylindrical portion and the lower cylindrical portion are connected to each other with a screw, when the flange of the upper cylindrical portion is mounted on the pipe mounting portion, the lower cylindrical portion is mounted. The ultrasonic wave from the piezoelectric ceramics mounted inside the mirror is prevented from being reflected at the screw connection portion and leaking from the flange of the upper cylindrical portion to the pipe, and the lower cylindrical portion is connected to the first and second cylindrical portions. By dividing into irradiation plates on which piezoelectric ceramics are mounted, and by electron beam welding each of them, further, by reducing ultrasonic waves propagating from the irradiation plate to the second cylindrical portion via the first cylindrical portion, There is an advantage that ultrasonic waves can be prevented from leaking into the pipe from the flange of the upper cylindrical portion, and the flow rate can be accurately measured.
[Brief description of the drawings]
FIG. 1 is a sectional view of an ultrasonic flowmeter sensor according to an embodiment of the present invention.
FIG. 2 is a side view of the ultrasonic flowmeter sensor of FIG. 1;
FIG. 3 is a side sectional view of a conventional ultrasonic flowmeter.
[Explanation of symbols]
6 Upper cylindrical part 7 Central member 8 Lower cylindrical part 9 Piezoelectric ceramics 10 Resin sheet 11 Resin

Claims (4)

An upper cylindrical portion having a lower end formed with a flange protruding outward, a thread provided inside, and an internal holding portion formed at a slight interval above the flange to form an internal pressing portion, and a thread formed inside the upper end; A thread engaging with a thread inside the upper end of the upper cylindrical portion is engaged with a thread formed in the lower projecting portion, and an upper projecting portion is formed from a center hole of the lower projecting portion, and an upper end of the upper projecting portion is formed. A lid member provided with a lid portion provided with a screw thread engaging with a thread formed on the outside, and a second cylindrical portion provided on an upper end of a first cylindrical portion having an ultrasonic irradiation plate mounted with piezoelectric ceramics fixed to an end thereof. A cylindrical portion is fixed, and a projecting portion projecting outward is formed at an upper end of the second cylindrical portion, and a lower cylindrical portion having a thread formed at an end of the projecting portion is formed. The outer thread of the protrusion of the second cylindrical portion is engaged with the thread at the lower end of the upper cylindrical portion to integrally form. And, ultrasonic flow meter sensor, characterized in that the resin is filled into the upper cylindrical part and a lower cylindrical portion. The fixing between the irradiation plate and the lower end of the first cylindrical portion of the lower cylindrical portion and the fixing between the upper end of the first cylindrical portion and the lower end of the second cylindrical portion are welded by electron beam welding. The ultrasonic flowmeter sensor according to claim 1, wherein: The ultrasonic flowmeter sensor according to claim 1, wherein a resin sheet is interposed between an inner protruding portion of the upper cylindrical portion and a protruding portion of a second cylindrical portion of the lower cylindrical portion. The ultrasonic flowmeter sensor according to claim 1, wherein the upper cylindrical portion, the lower cylindrical portion, and the lid member are made of stainless steel.

Images