Ultrasonic flowmeter

Abstract

The present invention provides an ultrasonic flowmeter that can minimize loss of measurement accuracy.　An ultrasonic flowmeter 1 comprises: a measurement channel C through which a fluid to be measured flows; a pair of ultrasonic transducers 14 disposed upstream and downstream of the measurement channel C; and an ultrasonic transducer fixation part 40 to which the ultrasonic transducers 14 are attached and which is formed integrally with the measurement channel C.

Description

Ultrasonic flowmeter ,

[0003]

[0001] The present disclosure relates to an ultrasonic flowmeter.

[0002] Patent Document 1 discloses an ultrasonic flowmeter that realizes highly accurate flow measurement even in a hydrogen environment where the sound speed is high and the wavelength is long, in a multi-layer ultrasonic flowmeter in which a flow path is divided by partition plates. This ultrasonic flowmeter forms a measurement flow path with a plurality of divided flow paths obtained by dividing a cylindrical flow path having a rectangular cross section with a plurality of partition plates, and the partition plates are provided with openings on the partition plates in the short-circuit path with respect to the normal propagation path of ultrasonic waves, so that the adverse effect due to the interference of the diffracted wave signal passing through the short-circuit path with respect to the normal propagation path can be minimized. Therefore, even in a hydrogen environment where the sound speed is high and the wavelength is long, a highly accurate ultrasonic flowmeter can be constructed.

[0003] Japanese Unexamined Patent Application Publication No. 2022 - 149008 <00​​​​​​​​​​​

[0008] (Knowledge and other information forming the basis of this disclosure) At the time the inventors conceived of this disclosure, there was a technology to form an ultrasonic flow meter by providing an ultrasonic transducer fixing section in the measurement channel through which the fluid to be measured flows, thereby fixing an ultrasonic transducer to the measurement channel. In this ultrasonic flow meter, the ultrasonic transducer transmits ultrasonic waves to the measurement channel, and the ultrasonic transducer receives the ultrasonic waves reflected from the measurement channel, thereby measuring the flow velocity and flow rate of the fluid to be measured. Some such ultrasonic flow meters are formed by creating the measurement channel and the ultrasonic transducer fixing section as separate components, and attaching the ultrasonic transducer fixing section to the measurement channel.

[0009] However, in such ultrasonic flowmeters, the measurement channel and the ultrasonic transducer mounting section are formed as separate components, which increases the number of parts and may lead to gaps or misalignment between the measurement channel and the ultrasonic transducer mounting section. The inventors discovered that this may reduce the accuracy of measuring the flow rate of the fluid being measured, and in order to solve this problem, they have come to form the subject of this disclosure. Therefore, this disclosure provides an ultrasonic flowmeter that can suppress the decrease in measurement accuracy.

[0010] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art. The accompanying drawings and the following explanation are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) Embodiment 1 will be described below with reference to Figures 1 to 6. In each figure, the symbol X indicates the direction in which the fluid to be measured flows in the ultrasonic flow meter. The symbol Y indicates the direction in which the partition plates 12 are aligned, perpendicular to the direction in which the fluid to be measured flows. The symbol Z indicates the direction in which the first surface portion 22 and the second surface portion 24 are aligned, perpendicular to the direction in which the fluid to be measured flows and the direction in which the partition plates 12 are aligned. In the following description, each direction is a direction along the direction of these ultrasonic flow meters.

[0012] [1-1. Structure of an Ultrasonic Flowmeter] Figure 1 is a perspective view of an ultrasonic flowmeter 1 according to Embodiment 1 of the present disclosure. As shown in Figure 1, the ultrasonic flowmeter 1 is a device installed in the middle of a pipe through which the fluid to be measured flows, and measures the fluid to be measured flowing inside the pipe. The ultrasonic flowmeter 1 can measure various fluids that ultrasonic waves can pass through, such as gases like methane and hydrogen, or tap water and industrial water, as the fluid to be measured. In the following description, the fluid to be measured will be described as hydrogen gas, but it is not limited to this, and the ultrasonic flowmeter 1 of this embodiment may measure other fluids.

[0013] Figure 2 is a perspective view of the ultrasonic flowmeter 1 showing a cross-section in Plane II of Figure 1. In Figure 2, the normal propagation paths U1 and U2, which are the propagation paths through which most of the ultrasonic waves transmitted from each of the ultrasonic transducers 14 pass, are indicated by arrows. As shown in Figure 2, the ultrasonic flowmeter 1 is formed by attaching a partition plate 12, ultrasonic transducers 14, a control board 16, and a covering member 18 to the main body 10.

[0014] Figure 3 is a perspective view of the main body 10. As shown in Figure 3, the main body 10 comprises a flow channel pipe section 20, an upstream open end 30, a downstream open end 32, an ultrasonic transducer fixing section 40, an apparatus fixing section 50, and a covering member fixing section 60. The main body 10 is made of a resin material and is formed by integrally molding the entire structure, for example, by injection molding. As a result, the flow channel pipe section 20, the upstream open end 30, the downstream open end 32, the ultrasonic transducer fixing section 40, the apparatus fixing section 50, and the covering member fixing section 60 are integrally formed.

[0015] As a result, in the ultrasonic flowmeter 1, for example, variations and misalignments in the position of each part during assembly are suppressed compared to a case where the flow path pipe section 20, the ultrasonic transducer fixing section 40, and the device fixing section 50 are each molded separately and then connected. Therefore, the ultrasonic flowmeter 1 can suppress a decrease in measurement accuracy. In addition, the ultrasonic flowmeter 1 can reduce the number of parts, the man-hours required for manufacturing, and the complexity of the structure.

[0016] As shown in Figure 3, the flow channel section 20 is formed in a tubular shape with a substantially rectangular cross-section, and a measurement channel C through which the fluid to be measured flows is formed inside. As shown in Figures 2 and 3, the flow channel section 20 includes a first surface section 22 surrounding the measurement channel, a second surface section 24 positioned substantially parallel to and opposite the first surface section 22, a third surface section 26 positioned substantially perpendicular to the first surface section 22, and a fourth surface section 28 positioned opposite the third surface section 26. Each of the first surface section 22, the second surface section 24, the third surface section 26, and the fourth surface section 28 is formed in a rectangular flat plate shape in plan view, and is connected to each other to form a measurement channel C with a rectangular cross-section inside. The first surface section 22 corresponds to the "first surface" in this disclosure.

[0017] Openings 21 are provided at both ends of the flow channel section 20, allowing communication between the inside and outside of the flow channel section 20. The openings 21 are formed in a substantially rectangular shape when viewed from the longitudinal direction of the flow channel section 20.

[0018] An upstream open end 30 is provided at one end of the flow channel section 20 in the longitudinal direction. The upstream open end 30 is continuous with one end of each of the first surface section 22, the second surface section 24, the third surface section 26, and the fourth surface section 28, and has a pyramidal shape that widens circumferentially outward as it moves away from the flow channel section 20 along the longitudinal direction of the flow channel section 20. The inner surface of the upstream open end 30 is formed in a curved shape.

[0019] A downstream open end 32 is provided at the other end of the flow channel section 20 in the longitudinal direction. The downstream open end 32 comprises a continuous section 34 that is continuous with the other end of the flow channel section 20 along the longitudinal direction of the flow channel section 20, and an outlet section 36 that is continuous with the continuous section 34 and formed on the opposite side of the flow channel section 20, sandwiching the continuous section 34. The continuous section 34, when viewed from the longitudinal direction of the flow channel section 20, widens outward in the circumferential direction of the flow channel section 20 and is formed in a rectangular tubular shape that is larger than the flow channel section 20 and the opening 21. The outlet section 36, when viewed from the longitudinal direction of the flow channel section 20, widens outward in the circumferential direction of the continuous section 34 and is formed in a circular tubular shape that is larger than the continuous section 34.

[0020] In the ultrasonic flowmeter 1, the fluid to be measured flows from the upstream open end 30 into the measurement channel C of the flow channel pipe section 20, and after flowing through the measurement channel C, it flows out from the downstream open end 32. Therefore, the end of the flow channel pipe section 20 and the measurement channel C located on the upstream open end 30 side is the upstream side, and the end located on the downstream open end 32 side is the downstream side.

[0021] A pair of ultrasonic transducer fixing parts 40 are provided on the first surface 22. Each of the ultrasonic transducer fixing parts 40 is provided side by side with a predetermined distance between them, along the direction of flow of the fluid to be measured. Each of the ultrasonic transducer fixing parts 40 is formed in a cylindrical shape that protrudes outward from the first surface 22 toward the flow channel section 20. The ultrasonic transducer fixing part 40 located on the upstream side extends with an inclination toward the upstream side as it moves outward from the first surface 22 toward the flow channel section 20. The ultrasonic transducer fixing part 40 located on the downstream side extends with an inclination toward the downstream side as it moves outward from the first surface 22 toward the flow channel section 20.

[0022] As shown in Figure 2, an ultrasonic transducer 14 is attached to each of the ultrasonic transducer fixing sections 40. The ultrasonic transducer 14 is formed in a substantially disc shape and is a device capable of transmitting and receiving ultrasonic waves. The ultrasonic transducer 14 is attached to the end of each ultrasonic transducer fixing section 40 located opposite the first surface section 22 in the longitudinal direction.

[0023] The ultrasonic transducer 14 is mounted on the ultrasonic transducer fixing part 40 and covered by a cover member 13 from the opposite side of the ultrasonic transducer fixing part 40. The cover member 13 is formed in a substantially disc shape and is connected to the ultrasonic transducer fixing part 40 in a manner that covers the ultrasonic transducer 14. The ultrasonic transducer 14 is fixed to the ultrasonic transducer fixing part 40 by being sandwiched between the ultrasonic transducer fixing part 40 and the cover member 13. As a result, one of the pair of ultrasonic transducers 14 is positioned on the upstream side of the measurement channel C, and the other is positioned on the downstream side of the measurement channel C.

[0024] As shown in Figures 2 and 3, a communication hole 23 is provided in the first surface portion 22 at the location surrounded by the end of the ultrasonic transducer fixing portion 40 located on the first surface portion 22 side, and the hole penetrates through the first surface portion 22 in the thickness direction. The communication hole 23 is formed in a substantially rectangular shape in plan view and connects the measurement channel C with the internal space of the ultrasonic transducer fixing portion 40. The ultrasonic transducer fixing portion 40 transmits ultrasonic waves to the measurement channel C via the communication hole 23 and receives ultrasonic waves that travel from the measurement channel C through the communication hole 23 due to reflection or the like.

[0025] As shown in Figure 3, the first surface portion 22 is provided with a device fixing portion 50. Multiple device fixing portions 50 are arranged between the ultrasonic transducer fixing portions 40 and extend outward from the first surface portion 22 toward the flow channel portion 20. The device fixing portion 50 includes a substrate contact portion 52 and a substrate engaging portion 54. The substrate contact portion 52 protrudes in a direction further away from the flow channel portion 20 than the ultrasonic transducer fixing portion 40. A flat surface portion substantially parallel to the plane of the first surface portion 22 is formed at the tip of the substrate contact portion 52. The substrate engaging portion 54 protrudes in a direction further away from the flow channel portion 20 than the substrate contact portion 52. A claw-shaped engaging piece is formed at the tip of the substrate engaging portion 54.

[0026] As shown in Figure 2, a control board 16 is attached to the main body 10 via a device fixing part 50. Components such as a processor composed of a CPU (Central Processing Unit) and an MPU (Micro Processing Unit), and memory are mounted on the control board 16. The control board 16 functions as a control unit for the ultrasonic flow meter 1 by executing a control program stored in the memory. In this embodiment, the control board 16 is provided with a measurement unit that measures the propagation time of ultrasonic waves transmitted and received between a pair of ultrasonic transducers 14, and a calculation unit that determines the flow rate of the fluid to be measured based on the signal from this measurement circuit unit. The control board 16 is provided with terminals 17 to which predetermined wiring can be connected. The control board 16 corresponds to the "measuring device" in this disclosure.

[0027] The control board 16 is fixed to the main body 10 by the tip of the substrate contact portion 52 contacting the surface facing the main body 10, and the tip of the substrate engagement portion 54 engaging with the edge of the surface located on the opposite side of the main body 10.

[0028] The control board 16 is covered by a covering member 18 from the opposite side of the main body 10. The covering member 18 is positioned opposite the first surface 22 and has a shape that is recessed in the direction away from the first surface 22. The covering member 18 is attached to the main body 10 via a covering member fixing part 60. As shown in Figure 3, a plurality of covering member fixing parts 60 are arranged on the first surface 22 between the ultrasonic transducer fixing parts 40. The covering member fixing part 60 is provided with a claw-shaped engaging piece. The covering member 18 is fixed to the main body 10 by the engaging piece of the covering member fixing part 60 engaging with the engaging hole 18A provided on the edge of the covering member 18. The covering member 18 is provided with an insertion hole 19, which is a through hole that penetrates in the thickness direction of the covering member 18, at a position that overlaps with the terminal 17. In the ultrasonic flowmeter 1, wiring extending from outside the ultrasonic flowmeter 1 can be connected to the terminal 17 via the insertion hole 19.

[0029] Figure 4 is a perspective view showing an enlarged view of the area indicated by IV in Figure 2. In Figure 4, some of the multiple partition plates 12 are omitted. As shown in Figure 4, in the flow channel section 20, multiple second surface grooves 25 are provided on the second surface section 24. The second surface grooves 25 are formed in a groove shape that is recessed from the surface of the second surface section 24 facing the measurement flow channel C toward the surface located outside the flow channel section 20. In the longitudinal direction of the second surface section 24, the second surface grooves 25 extend from the downstream end of the second surface section 24 to the middle of the second surface section 24. In this embodiment, the second surface grooves 25 extend to a point located on the downstream side of the ultrasonic transducer fixing section 40 in a plan view of the second surface section 24. The multiple second surface grooves 25 are arranged at equal intervals from each other so as to extend substantially parallel to each other along the direction in which the third surface section 26 and the fourth surface section 28 are aligned.

[0030] Figure 5 is a perspective view showing the first surface groove 29. As shown in Figure 5, the first surface portion 22 is provided with a plurality of first surface grooves 29. The first surface groove 29 is formed in a groove shape that is recessed from the surface of the first surface portion 22 facing the measurement flow path C toward the surface located outside the flow path pipe portion 20. The first surface groove 29 extends in the longitudinal direction of the first surface portion 22 from the downstream end of the first surface portion 22 to the middle of the first surface portion 22. In this embodiment, the first surface groove 29 extends to a location located between the pair of ultrasonic transducer fixing portions 40. The plurality of first surface grooves 29 are arranged at equal intervals from each other so as to extend substantially parallel to each other along the direction in which the third surface portion 26 and the fourth surface portion 28 are aligned.

[0031] Figure 6 is a perspective view showing multiple partition plates 12. As shown in Figures 1 and 2, multiple partition plates 12 are housed inside the flow channel section 20. As shown in Figure 6, the partition plates 12 are made of, for example, a metal material and are plate-shaped members that are substantially rectangular in plan view. The partition plates 12 are formed with a length that is substantially the same as, or shorter than, the longitudinal dimensions of the flow channel section 20 in the longitudinal direction. In a plan view, the partition plates 12 are formed with a length that is substantially the same as the distance between the first surface 22 and the second surface 24 in a direction perpendicular to the longitudinal direction.

[0032] In the partition plate 12, one of a pair of sides located perpendicular to the longitudinal direction is provided with a first projection 70, and the other side is provided with a second projection 72. Both the first projection 70 and the second projection 72 protrude outward in a plan view of the partition plate 12 along a direction perpendicular to the longitudinal direction, with a predetermined width. In the longitudinal direction of the partition plate 12, the first projection 70 extends from one end to the middle of the partition plate 12 in the longitudinal direction, with a length approximately the same as that of the first surface groove 29. In the longitudinal direction of the partition plate 12, the second projection 72 extends from one end to the middle of the partition plate 12 in the longitudinal direction, with a length approximately the same as that of the second surface groove 25.

[0033] The partition plate 12 is provided with a plurality of straightening holes 71. The straightening holes 71 are through holes that penetrate the partition plate 12 along the thickness direction. The plurality of straightening holes 71 are arranged in a manner that forms a substantially isosceles triangle in plan view, approximately midway along the longitudinal direction of the partition plate 12. The isosceles triangle formed by the straightening holes 71 has one side extending along the side of the partition plate 12 where the first projection 70 is provided, and its vertex is positioned to project toward the side of the partition plate 12 where the second projection 72 is provided. The straightening holes 71 are provided in the partition plate 12, for example, by etching. The straightening holes 71 correspond to the "notches or openings" in this disclosure.

[0034] As shown in Figure 2, in this embodiment, each of the partition plates 12 is inserted into the interior of the flow channel section 20 from the other end side through the opening 21 located on the downstream side, in a position where its plane is substantially parallel to the planes of the third surface section 26 and the fourth surface section 28, respectively. When each of the partition plates 12 is inserted into the interior of the flow channel section 20, the first projection 70 fits into the first surface groove 29, and the second projection 72 fits into the second surface groove 25. In this way, each of the partition plates 12 is fixed to the flow channel section 20 in a state where they are arranged at equal intervals from each other along the direction in which the third surface section 26 and the fourth surface section 28 are aligned. In this arrangement, one side of a pair of sides located in a direction perpendicular to the longitudinal direction abuts against the first surface section 22, and the other side abuts against the second surface section 24. As a result, the partition plate 12 divides the measurement channel C at equal intervals along the direction in which the third surface portion 26 and the fourth surface portion 28 are aligned. Therefore, multiple divided channels D having substantially the same width are formed inside the channel pipe portion 20 in the direction in which the third surface portion 26 and the fourth surface portion 28 are aligned.

[0035] [1-2. Operation of the Ultrasonic Flowmeter] The operation of the ultrasonic flowmeter 1 configured as described above will be explained below. As shown in Figure 2, when the fluid to be measured flows inside the measurement channel C, the fluid to be measured is divided to each of the partition plates 12 and flows through each of the divided channels D. As a result, in the ultrasonic flowmeter 1, the flow velocity distribution of the fluid to be measured in the direction in which the third surface portion 26 and the fourth surface portion 28 are aligned becomes approximately uniform.

[0036] In the ultrasonic flowmeter 1, ultrasonic waves are transmitted from each of the ultrasonic transducers 14 to the fluid to be measured, and the ultrasonic transducers 14 receive the reflected ultrasonic waves to measure the flow velocity and calculate the flow rate of the fluid to be measured. Most of the ultrasonic waves transmitted from one ultrasonic transducer 14 travel through the communication holes 23, as indicated by the arrows U1 and U2, from the ultrasonic transducer fixing part 40 towards the measurement channel C. These ultrasonic waves enter each of the divided channel D inside the channel pipe section 20, are reflected from the surface of the second surface section 24 facing the measurement channel C, and enter the other ultrasonic transducer fixing part 40 through the other communication hole 23, where they are received by the other ultrasonic transducer 14. In the following description, the ultrasonic wave propagation paths indicated by the arrows U1 and U2 are referred to as normal propagation paths U1 and U2.

[0037] A portion of the ultrasonic waves transmitted from one ultrasonic transducer 14 may become diffracted waves and, after entering the measurement channel C, may not be reflected by the surface of the second surface 24 facing the measurement channel C. Such diffracted waves may pass through the region enclosed by the normal propagation paths U1 and U2 and the first surface 22 in a side view of the channel tube 20 and be received by the other ultrasonic transducer 14. In the following explanation, the region enclosed by the normal propagation paths U1 and U2 and the first surface 22 will be referred to as the short-circuit path S.

[0038] In this embodiment, when each of the partition plates 12 is inserted into the flow channel section 20, each of the rectifier holes 71 is positioned to correspond to the short-circuit path S. As a result, in the ultrasonic flowmeter 1, diffracted waves passing through the short-circuit path S pass through each of the rectifier holes 71, and amplification of the amplitude of said diffracted waves is suppressed. Therefore, in the ultrasonic flowmeter 1, interference between the normal ultrasonic waves that have passed through the normal propagation paths U1 and U2 and the diffracted waves passing through the short-circuit path S is suppressed. In addition, in the ultrasonic flowmeter 1, the fluid to be measured in each of the divided flow channels D is rectified by the provision of the rectifier holes 71. Therefore, the ultrasonic flowmeter 1 can improve the measurement accuracy.

[0039] In the ultrasonic flowmeter 1, when ultrasonic waves are received by each of the ultrasonic transducers 14, the measurement unit of the control board 16 performs processing such as measuring the propagation time, and the calculation unit performs calculations such as the flow velocity and flow rate of the fluid being measured.

[0040] [1-3. Effects, etc.] As described above, in this embodiment, the ultrasonic flowmeter 1 comprises a measurement channel C with a rectangular cross-section through which the fluid to be measured flows, a pair of ultrasonic transducers 14 arranged upstream and downstream of the measurement channel C, and an ultrasonic transducer fixing part 40 to which the ultrasonic transducers 14 are attached and which is formed integrally with the measurement channel C.

[0041] As a result, the ultrasonic flowmeter 1 can eliminate gaps in the joint between the ultrasonic transducer fixing part 40 and the measurement channel C, as well as deviations in ultrasonic propagation distance caused by variations in the fixing positions of the pair of ultrasonic transducers 14 that occur when assembling the ultrasonic transducer fixing part 40 and the measurement channel C. Therefore, the ultrasonic flowmeter 1 can achieve highly accurate flow rate measurement.

[0042] As in this embodiment, the measurement channel C is provided with openings 21 at both ends located in the flow direction of the fluid to be measured. Inside the measurement channel C, a partition plate 12 may be provided, which is inserted into the measurement channel C from at least one of the openings 21 and is arranged parallel to the flow direction of the fluid to be measured, thereby dividing the measurement channel C into multiple divided channels. With this configuration, even if the ultrasonic transducer fixing part 40 and the measurement channel C are not separated, as in the component configuration of a conventional ultrasonic flow meter 1, and the ultrasonic transducer fixing part 40 and the measurement channel C are integrated, the partition plate 12 can be attached from the opening 21. Therefore, a simple ultrasonic flow meter 1 with a reduced number of parts can be constructed. In addition, the partition plate 12 can be provided with flow straightening holes 71 to reduce the interference effect of diffracted waves passing through the short-circuit path S of the pair of ultrasonic transducers 14. Therefore, the ultrasonic flow meter 1 can improve the accuracy of flow measurement even for fluids to be measured, such as hydrogen, which have a high sound velocity and long wavelength.

[0043] As in this embodiment, each of the ultrasonic transducers 14 is provided on the first surface of the measurement channel C. The partition plate 12 is provided with a short-circuit path S, which is a region formed by the normal propagation paths U1 and U2 and the first surface, by short-circuiting the normal propagation paths U1 and U2, through which ultrasonic waves propagate from one ultrasonic transducer 14 to the other ultrasonic transducer 14 in a normal path. The short-circuit path S is provided with a rectifier hole 71 that connects the divided channels, and notches and openings 21 do not need to be provided in regions of the partition plate 12 that are different from the short-circuit path S. With this, the ultrasonic flowmeter 1 can improve the accuracy of flow measurement even for fluids to be measured, such as hydrogen, which have a high sound velocity and long wavelength.

[0044] As in this embodiment, a resin material is used for the partition plate 12, and the flow rectifying holes 71 may be formed as the partition plate 12 is molded. According to this, the processing steps of the partition plate 12 can be simplified. Therefore, in the ultrasonic flowmeter 1, productivity is improved and high cost performance can be achieved.

[0045] As in this embodiment, a control board 16 that measures the propagation time of ultrasonic waves traveling from one ultrasonic transmitter / receiver 14 to the other ultrasonic transmitter / receiver 14, and a device fixing portion 50 to which the control board 16 is attached are provided. The device fixing portion 50 and the ultrasonic transmitter / receiver fixing portion 40 may be integrally formed. According to this, in the ultrasonic flowmeter 1, the number of components can be reduced. Therefore, in the ultrasonic flowmeter 1, the steps related to assembly can be simplified, productivity is improved, and high cost performance can be achieved.

[0046] (Embodiment 2) Hereinafter, Embodiment 2 will be described with reference to FIGS. 7 to 13. [2-1. Structure of Ultrasonic Flowmeter] FIG. 7 is a perspective view of an ultrasonic flowmeter 1 according to Embodiment of the present disclosure. FIG. 8 is a perspective view of the main body portion 10. FIG. 9 is a perspective view of the cross section in plane IX of FIG. 8 viewed from above. FIG. 10 is a perspective view of the cross section in plane IX of FIG. 8 viewed from below. In FIGS. 8 to 10, the same parts as those in FIGS. 1 to 5 are denoted by the same reference numerals, and the description thereof will be omitted. As shown in FIGS. 7 to 10, a welding portion 80 is provided in the main body portion 10 of this embodiment.

[0047] The welding portion 80 has a concave shape that departs outward from the flow path tube portion 20 over a surface that is continuous with the surface facing the measurement flow path C in each of the third surface portion 26 and the fourth surface portion 28, from the end portion located on the downstream side among the surfaces facing the measurement flow path C. Among the welding portion 80, the portion located in the continuous portion 34 is formed such that the width dimension in the direction in which the first surface portion 22 and the second surface portion 24 are arranged is larger than the portions located in the third surface portion 26 and the fourth surface portion 28, respectively.

[0048] The welded part 80 of the present embodiment is disposed at a substantially central portion in the main body portion 10 in the direction in which the first surface portion 22 and the second surface portion 24 are arranged when viewed from the flow direction of the fluid to be measured. Note that the welded part 80 is not limited to this, and may be provided at any position in the direction in which the first surface portion 22 and the second surface portion 24 are arranged.

[0049] In the welded part 80, a main body melting part 82 is provided at a location positioned in the continuous part 34. The main body melting part 82 is formed in a rod shape extending along the flow direction of the fluid to be measured from the downstream ends of each of the third surface portion 26 and the fourth surface portion 28 inside the location positioned in the continuous part 34 of the welded part 80. The main body melting part 82 is arranged at a predetermined interval along the direction in which the first surface portion 22 and the second surface portion 24 are arranged inside the location positioned in the continuous part 34 of the welded part 80.

[0050] As shown in FIGS. 9 and 10, in the main body portion 10 of the present embodiment, instead of the first surface groove 29 and the second surface groove 25, a first fitting groove 129 and a second fitting groove 125 are provided. As shown in FIG. 9, in the flow path pipe portion 20, a plurality of second fitting grooves 1,25 are provided in the second surface portion 24. The second fitting groove 125 is formed in a groove shape that depresses from the surface of the second surface portion 24 facing the measurement flow path C toward the surface positioned outside the flow path pipe portion 20. In the longitudinal direction of the second surface portion 24, the second fitting groove 125 extends from the downstream end of the second surface portion 24 to the upstream end of the second surface portion 24. The plurality of second fitting grooves 125 are arranged side by side at equal intervals so as to extend substantially parallel to each other along the direction in which the third surface portion 26 and the fourth surface portion 28 are arranged.

[0051] As shown in FIG. 10, a plurality of first fitting grooves 129 are provided in the first surface portion 22. The first fitting groove 129 is formed in a groove shape that depresses from the surface of the first surface portion 22 facing the measurement flow path C toward the surface positioned outside the flow path pipe portion 20. The first fitting groove 129 extends from the downstream end of the first surface portion 22 to the upstream end of the first surface portion 22 in the longitudinal direction of the first surface portion 22. The plurality of first fitting grooves 129 are arranged side by side at equal intervals so as to extend substantially parallel to each other along the direction in which the third surface portion 26 and the fourth surface portion 28 are arranged.

[0052] Figure 11 is a perspective view showing the partition plate unit 120. As shown in Figure 7, the main body 10 of this embodiment is provided with a partition plate unit 120 instead of a plurality of partition plates 12. The partition plate unit 120 is made of resin material and is formed by integrally molding the entire unit, for example, by injection molding.

[0053] The partition plate unit 120 comprises a plurality of partition plate sections 122. Each partition plate section 122 is a plate-like member that is substantially rectangular in plan view. The partition plate section 122 is formed with a length that is substantially the same as, or shorter than, the longitudinal dimensions of the flow channel section 20 in the longitudinal direction. The partition plate section 122 is formed with a length that is substantially the same as the distance between the first surface section 22 and the second surface section 24 in a direction perpendicular to the longitudinal direction in plan view.

[0054] The partition plate portion 122 is provided with a notch 123 formed by cutting out the edge located on the first surface portion 22 side toward the second surface portion 24 side by a predetermined width. The notch 123 is provided in the middle of the partition plate portion 122 in the flow direction of the fluid to be measured.

[0055] The partition plate portion 122 is provided with a plurality of flow-straightening notches 171, which are formed by cutting out an edge portion formed by the notch portion 123 and then further cutting out a predetermined width toward the second surface portion 24. The flow-straightening notches 171 are arranged in a line in the flow direction of the fluid to be measured and are located approximately in the center of the area where the notch portion 123 is provided. Each of the flow-straightening notches 171 is cut deeper in the direction in which the first surface portion 22 and the second surface portion 24 are aligned as it approaches approximately the center of the area where the notch portion 123 is provided. The flow-straightening notches 171 correspond to the "notch or opening" in this disclosure.

[0056] Each of the partition plate sections 122 is connected by an upstream connecting section 124 and a downstream connecting section 126. The upstream connecting section 124 and the downstream connecting section 126 are both formed in a rod shape with a predetermined length. The upstream connecting section 124 and the downstream connecting section 126 are provided so as to penetrate each of the partition plate sections 122, which are arranged in the direction in which the third surface section 26 and the fourth surface section 28 are aligned, with their planes facing each other substantially parallel to one another, in the thickness direction. The upstream connecting section 124 is provided at the upstream end of each partition plate section 122 in the flow direction of the fluid being measured, and the downstream connecting section 126 is provided at the downstream end of each partition plate section 122 in the flow direction of the fluid being measured.

[0057] The upstream connecting portion 124 is formed with a length dimension that is less than or equal to the distance between the third surface portion 26 and the fourth surface portion 28 in the direction in which the third surface portion 26 and the fourth surface portion 28 are aligned. The downstream connecting portion 126 is formed with a length dimension that is greater than or equal to the distance between the third surface portion 26 and the fourth surface portion 28 in the direction in which the third surface portion 26 and the fourth surface portion 28 are aligned.

[0058] In this embodiment, the upstream connecting portion 124 and the downstream connecting portion 126 are positioned in the partition plate unit 120 approximately in the center of the direction in which the first surface portion 22 and the second surface portion 24 are aligned, when viewed from the direction of fluid flow to be measured. However, the upstream connecting portion 124 and the downstream connecting portion 126 may be provided at any position in the direction in which the first surface portion 22 and the second surface portion 24 are aligned.

[0059] Unit melting sections 130 are provided at both ends of the downstream connecting section 126. The unit melting sections 130 are formed in a rod shape that protrudes from both ends of the downstream connecting section 126 by a predetermined length in the direction of the fluid to be measured.

[0060] The multiple partition plate sections 122, the upstream connecting section 124, and the downstream connecting section 126 are formed as a single unit. In other words, each of the multiple partition plate sections 122 is connected to each other by the upstream connecting section 124 and the downstream connecting section 126, making it possible to injection mold them as a single unit using resin material. Therefore, in the ultrasonic flow meter 1, compared to, for example, a case where each of the partition plate sections 122 is molded separately and then connected, variations and misalignments in the position of each part during assembly are suppressed, as well as a reduction in the number of parts and the man-hours required for manufacturing.

[0061] [2-2. Procedure for Manufacturing an Ultrasonic Flowmeter] As shown in Figure 7, in this embodiment, each of the partition plate units 120 is inserted into the flow channel section 20 from the other end through the opening 21 located on the downstream side, in a position where each plane of the partition plate section 122 is substantially parallel to the planes of the third surface section 26 and the fourth surface section 28. When each of the partition plate sections 122 is inserted into the flow channel section 20, the end on the first surface section 22 side fits into the first fitting groove 129, and the end on the second surface section 24 side fits into the second fitting groove 125. In this way, each of the partition plates 12 is fixed to the flow channel section 20 in a state where they are arranged at equal intervals from each other along the direction in which the third surface section 26 and the fourth surface section 28 are aligned. The partition plates 12 arranged in this manner partition the measurement flow channel C at equal intervals along the direction in which the third surface section 26 and the fourth surface section 28 are aligned. Therefore, multiple divided channels D having substantially the same width are formed inside the flow channel section 20 in the direction in which the third surface section 26 and the fourth surface section 28 are aligned.

[0062] Figure 12 is a perspective view showing the welded portion 80 before welding. Figure 13 is a perspective view showing the welded portion 80 after welding. As shown in Figure 12, when each of the partition plate units 120 is inserted into the flow channel section 20, each of the unit melting sections 130 is housed inside the welded portion 80 and positioned between the main body melting sections 82. In this state, for example, by performing thermal welding, ultrasonic welding, or high-frequency welding, the unit melting sections 130 and the main body melting sections 82 melt, as shown in Figure 13. As a result, the partition plate units 120 are fixed to the main body section 10.

[0063] In this embodiment, when each of the partition plate sections 122 is inserted into the flow channel section 20, each of the flow straightening notches 171 is positioned to correspond to the short-circuit path S. As a result, in the ultrasonic flowmeter 1, diffracted waves passing through the short-circuit path S pass through each of the flow straightening notches 171, and amplification of the amplitude of said diffracted waves is suppressed. Therefore, in the ultrasonic flowmeter 1, interference between the normal ultrasonic waves that have passed through the normal propagation paths U1 and U2 and the diffracted waves passing through the short-circuit path S is suppressed. In addition, in the ultrasonic flowmeter 1, the fluid to be measured in each of the divided flow channels D is straightened by the provision of the flow straightening notches 171. Therefore, the ultrasonic flowmeter 1 can improve the measurement accuracy.

[0064] [2-3. Effects, etc.] As described above, in this embodiment, the ultrasonic flowmeter 1 is provided with a plurality of partition plates 12, and each of the partition plates 12 is connected to one another and arranged inside the measurement flow path C. With this, the ultrasonic flowmeter 1 can reduce the number of parts, reduce the manufacturing time and suppress the complexity of the structure.

[0065] As in this embodiment, the partition plate unit 120 is provided with a unit melting section 130 that deforms to be fixed to the main body 10. This reduces the number of fastening members and other components used to connect parts such as screw members in the ultrasonic flow meter 1. As a result, the number of parts in the ultrasonic flow meter 1 is reduced, which helps to lower the manufacturing time and suppress the complexity of the structure.

[0066] (Other Embodiments) As described above, Embodiments 1 and 2 have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited thereto and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to create new embodiments by combining the components described in Embodiments 1 and 2 above. Therefore, other embodiments are described below as examples.

[0067] In the above-described embodiment, the partition plate 12 and the partition plate portion 122 are provided with rectifying holes 71 and rectifying notches 171. However, the invention is not limited to this, and the partition plate 12 and the partition plate portion 122 may be provided with any shape as long as they are positioned to overlap the short-circuit path S and penetrate in the thickness direction to connect each of the divided flow paths D. For example, the partition plate 12 and the partition plate portion 122 may be made of punched holes with a large number of mechanically made holes, or a mesh body such as wire mesh.

[0068] In the above-described embodiment, the rectifier holes 71 and the rectifier notches 171 are arranged in a manner that forms an approximately isosceles triangle in plan view, approximately midway along the longitudinal direction of the partition plate 12 and the partition plate portion 122. However, the invention is not limited to this, and the multiple rectifier holes 71 may be arranged in any way as long as they are located within the region enclosed by the normal propagation paths U1 and U2 and the first surface portion 22.

[0069] In the above-described embodiment, the multiple rectifier holes 71 are arranged in a manner that forms an approximately isosceles triangle in plan view, approximately midway along the longitudinal direction between the first partition plate portion 12A and the second partition plate portion 12B. However, the invention is not limited to this arrangement, and the multiple rectifier holes 71 may be arranged in any way as long as they are located within the region enclosed by the normal propagation paths U1 and U2 and the first surface portion 22.

[0070] The embodiments described above are for illustrative purposes only and may be modified, replaced, added, or omitted within the scope of the claims or equivalents thereof.

[0071] (Note) The above description of embodiments discloses the following technology.

[0072] (Technology 1) An ultrasonic flow meter comprising a measurement channel through which the fluid to be measured flows, a pair of ultrasonic transducers arranged upstream and downstream of the measurement channel, and an ultrasonic transducer fixing part to which the ultrasonic transducers are attached and which is formed integrally with the measurement channel. This eliminates the gap at the joint between the ultrasonic transducer fixing part and the measurement channel, and the occurrence of deviations in ultrasonic propagation distance due to variations in the fixing position of the pair of ultrasonic transducers that occur when assembling the ultrasonic transducer fixing part and the measurement channel. Therefore, high-precision flow measurement can be achieved.

[0073] (Technology 2) The ultrasonic flow meter according to Technology 1, wherein the measurement channel has openings at both ends located in the direction of the flow of the fluid to be measured, and a partition plate is provided inside the measurement channel, which is inserted into the measurement channel from at least one of the openings and is arranged parallel to the direction of the flow of the fluid to be measured, thereby dividing the measurement channel into multiple divided channels. With this, even if the ultrasonic transducer fixing part and the measurement channel are not separated as in the component configuration of conventional ultrasonic flow meters, and the ultrasonic transducer fixing part and the measurement channel are integrated, the partition plate can be attached from the opening. For this reason, a simple ultrasonic flow meter with a reduced number of parts can be constructed. Furthermore, since the partition plate can be provided with openings to minimize the interference effect of diffracted wave signals passing through the short-circuit path of a pair of ultrasonic transducers, high-precision flow measurement can be achieved even for fluids to be measured such as hydrogen, which have a high sound velocity and long wavelength.

[0074] (Technology 3) An ultrasonic flow meter according to Technology 2, wherein a plurality of partition plates are provided, and each of the partition plates is connected to one another and arranged inside the measuring channel. This makes it possible to construct a simple ultrasonic flow meter with an even smaller number of parts.

[0075] (Technical 4) An ultrasonic flow meter according to Technical 2 or Technical 3, wherein at least one of the measuring channel and the partition plate is provided with a fixing part that deforms to fix to the other. This eliminates the need for additional parts such as screws. Therefore, a simple ultrasonic flow meter with a reduced number of parts can be constructed.

[0076] (Technical 5) An ultrasonic flowmeter according to any one of Technical 2 to 4, wherein each of the ultrasonic transducers is provided on the first surface of the measurement channel, and the partition plate is provided with a short-circuit path which is a region formed by the normal propagation path in which ultrasonic waves propagate from one ultrasonic transducer to the other ultrasonic transducer in a normal path, and the short-circuit path is provided with a notch or opening that connects the divided channels, and the region of the partition plate different from the short-circuit path is not provided with the notch or opening.

[0077] (Technical 6) The ultrasonic flow meter according to Technical 5, wherein the partition plate is made of a resin material, and the notch or opening is formed during the molding of the partition plate. This simplifies the processing steps for the partition plate. As a result, productivity is improved, and an ultrasonic flow meter with high cost performance can be constructed.

[0078] (Technical 7) An ultrasonic flow meter according to any one of Technical 1 to Technical 6, comprising a measuring device for measuring the propagation time of ultrasonic waves from one ultrasonic transducer to the other ultrasonic transducer, and a device fixing part to which the measuring device is attached, wherein the device fixing part and the ultrasonic transducer fixing part are integrally formed. With this, the number of parts in the ultrasonic flow meter can be reduced. As a result, the assembly process in the ultrasonic flow meter can be simplified, productivity can be improved, and high cost performance can be achieved.

[0079] This disclosure is applicable to ultrasonic flowmeters that measure the flow velocity and flow rate of a fluid under test. Specifically, this disclosure is applicable to various gas meters and measuring instruments, such as those for hydrogen.

[0080] 1. Ultrasonic flow meter 10. Main body 12. Partition plate 13. Cover member 14. Sound wave transducer 16. Control board 17. Terminal 18. Covering member 18A. Engagement hole 19. Insertion hole 20. Flow path pipe 21. Opening 22. First surface 23. Communication hole 24. Second surface 25. Second surface groove 26. Third surface 28. Fourth surface 29. First surface groove 30. Upstream open end 32. Downstream open end 34. Continuous section 36. Outlet section 40. Sound wave transducer fixing section 50. Device fixing section 52. Substrate contact section 54. Substrate engagement section 60. Covering member fixing section 70. First protrusion 71. Rectifying hole 72. Second protrusion 80. Welded section 82. Main body melting section 120. Partition plate unit 122. Partition plate section 123 Notch section 124 Upstream connecting section 125 Second fitting groove 126 Downstream connecting section 129 First fitting groove 130 Unit melting section 171 Rectifying notch section C Measurement channel D Divided channel S Short-circuit path U1, U2 Normal propagation path

Claims

1. An ultrasonic flow meter comprising: a measuring channel through which the fluid to be measured flows; a pair of ultrasonic transducers arranged upstream and downstream of the measuring channel; and an ultrasonic transducer fixing section to which the ultrasonic transducers are attached and which is formed integrally with the measuring channel.

2. The ultrasonic flow meter according to claim 1, wherein the measuring channel is provided with openings at both ends located in the direction of the flow of the fluid to be measured, and a partition plate is provided inside the measuring channel, which is inserted into the measuring channel from at least one of the openings and is arranged parallel to the direction of the flow of the fluid to be measured, thereby dividing the measuring channel into a plurality of divided channels.

3. The ultrasonic flow meter according to claim 2, wherein a plurality of partition plates are provided, and each of the partition plates is connected to one another and arranged inside the measuring channel.

4. The ultrasonic flow meter according to claim 2 or 3, wherein at least one of the measuring channel and the partition plate is provided with a fixing portion that deforms to be fixed to the other.

5. The ultrasonic flow meter according to claim 2 or 3, wherein each of the ultrasonic transducers is provided on the first surface of the measurement channel, the partition plate is provided with a short-circuit path which is a region formed by the normal propagation path and the first surface, which short-circuits the normal propagation path through which ultrasonic waves propagate from one ultrasonic transducer to the other ultrasonic transducer, and the short-circuit path is provided with a notch or opening that connects the divided channels, and the region of the partition plate different from the short-circuit path is not provided with the notch and the opening.

6. The ultrasonic flow meter according to claim 5, wherein the partition plate is made of a resin material, and the notch or opening is formed during the molding of the partition plate.

7. An ultrasonic flow meter according to any one of claims 1 to 6, comprising: a measuring device for measuring the propagation time of ultrasonic waves from one ultrasonic transducer to the other ultrasonic transducer; and a device fixing part to which the measuring device is attached, wherein the device fixing part and the ultrasonic transducer fixing part are integrally formed.

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