Ultrasonic flowmeter

Abstract

Provided is an ultrasonic flowmeter that can be formed with a simple structure.　This ultrasonic flowmeter comprises: a first member; and a second member that connects to the first member. The first member is integrally provided with a first flow path wall, a first transducer holding part, and a first partition plate. The second member is integrally provided with a second flow path wall, a second transducer holding part, and a second partition plate. The first flow path wall and the second flow path wall are connected as a result of the second member being connected to the first member, and a measurement flow path, which has a rectangular cross-section and through which a fluid to be measured flows, is thereby formed. The first transducer holding part and the second transducer holding part are connected as a result of the second member being connected to the first member, and an ultrasonic transducer fixing part, to which a pair of ultrasonic transducers disposed upstream and downstream in the measurement flow path are attached, is thereby formed. The first partition plate and the second partition plate are disposed substantially parallel to a flow direction of the fluid to be measured as a result of the second member being connected to the first member, and the measurement flow path is thereby divided into a plurality of sections.

Description

Ultrasonic flowmeter

[0001] This disclosure relates to an ultrasonic flowmeter.

[0002] Patent Document 1 discloses an ultrasonic flowmeter that realizes high-precision flow measurement even in a hydrogen environment where the speed of sound 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 17 with a plurality of divided flow paths obtained by dividing a cylindrical flow path with a rectangular cross-section by a plurality of partition plates. 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 signals passing through the short-circuit path with respect to the normal propagation path can be minimized. Therefore, even in a hydrogen environment where the speed of sound is high and the wavelength is long, a highly accurate ultrasonic flowmeter can be constructed.

[0003] Japanese Patent Application Laid-Open No. 2022-149008

[0004] This disclosure provides an ultrasonic flowmeter that can be formed with a simple structure.

[0005] This specification includes all the contents of Japanese Patent Application No. 2025-019499 filed on February 7, 2025. The ultrasonic flowmeter in this disclosure includes a first member and a second member connected to the first member. The first member is integrally provided with a first flow path wall portion, a first ultrasonic transducer holding portion, and a first partition plate portion, and the second member is integrally provided with a second flow path wall portion, a second ultrasonic transducer holding portion, and a second partition plate portion. The first flow path wall portion and the second flow path wall portion are connected by connecting the second member to the first member, forming a measurement flow path with a rectangular cross-section through which the fluid to be measured flows. The first ultrasonic transducer holding portion and the second ultrasonic transducer holding portion are connected by connecting the second member to the first member, forming an ultrasonic transducer fixing portion to which a pair of ultrasonic transducers arranged upstream and downstream of the measurement flow path are attached. The first partition plate portion and the second partition plate portion are arranged substantially parallel to the flow direction of the fluid to be measured by connecting the second member to the first member, and the measurement flow path is formed into a plurality of divided flow paths.

[0006] According to this disclosure, it can be formed with a simple structure.

[0007] Figure 1 is a perspective view of an ultrasonic flowmeter according to the present disclosure. Figure 2 is a perspective view of the ultrasonic flowmeter. Figure 3 is a front view of the ultrasonic flowmeter. Figure 4 is an exploded perspective view of the ultrasonic flowmeter. Figure 5 is a side view of the first member.

[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 unit for fixing an ultrasonic transducer to the measurement channel and a partition plate for partitioning the inside of the measurement channel in the measurement channel through which the fluid to be measured flows. 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 flowing through the measurement channel. Some such ultrasonic flow meters are formed by separately forming the measurement channel, the ultrasonic transducer fixing unit, and the partition plate, and then attaching the ultrasonic transducer fixing unit and the partition plate to the measurement channel.

[0009] However, the inventors discovered that in such ultrasonic flowmeters, the measurement channel, the ultrasonic transducer fixing part, and the partition plate are formed as separate components, which increases the number of parts and the amount of work involved in their formation, and may also complicate the structure. To solve this problem, the subject of this disclosure was established. Therefore, this disclosure provides an ultrasonic flowmeter that can be formed with a simple structure.

[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 5. 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 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 and the second surface are aligned, perpendicular to the direction in which the fluid to be measured flows and the direction in which the partition plates 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 this disclosure, viewed from the upstream side. Figure 2 is a perspective view of the ultrasonic flowmeter 1 viewed from the downstream side. Figure 3 is a front view of the ultrasonic flowmeter 1 viewed from the downstream side. As shown in Figures 1 to 3, 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] The ultrasonic flowmeter 1 is formed by attaching an ultrasonic transducer 14 and a control board 16 to a main body 10, which is formed by connecting a first member 2 and a second member 4.

[0014] As shown in Figures 1 to 3, the main body 10 comprises a first partition plate section 12A, a second partition plate section 12B, a flow channel pipe section 20, an upstream open end 30, a downstream open end 32, an ultrasonic transducer fixing section 40, and an apparatus fixing section 50.

[0015] 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. The flow channel section 20 comprises 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 flow channel section 20 corresponds to the "tubular section" in this disclosure.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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 comprises a conduit part 42 and a housing part 44. Each conduit part 42 is formed in a cylindrical shape that protrudes outward from the first surface 22 toward the flow channel 20. The conduit part 42 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 20. The conduit part 42 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 20.

[0021] As shown in Figure 2, a housing section 44 is provided at each end of the conduit section 42 located opposite the first surface section 22 in the longitudinal direction. The housing section 44 is formed in the shape of a disc or cylinder, having substantially the same central axis as the conduit section 42. The housing section 44 has a space inside, which communicates with the internal space of the conduit section 42. The ultrasonic transducer 14 is housed in the internal space of the housing section 44.

[0022] The ultrasonic transducer 14 is formed in a roughly disc shape and is a device capable of transmitting and receiving ultrasonic waves. The pair of ultrasonic transducers 14 are housed in each of the housing sections 44, so that one 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.

[0023] Figure 4 is a side view of the first member 2 as seen from the third surface portion 26 side. In Figure 4, 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 4, in the first surface portion 22, a communication hole 23 is provided that penetrates in the thickness direction of the first surface portion 22 at the location surrounded by the end of the conduit portion 42 located on the first surface portion 22 side. 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, etc.

[0024] As shown in Figures 1 to 4, a device fixing part 50 is provided at the upper end of a pair of ultrasonic transducer fixing parts 40. The device fixing part 50 is formed in the shape of a roughly rectangular parallelepiped housing and is integrally provided on each of the housing parts 44, with one side spanning across the upper end of each of the pair of ultrasonic transducer fixing parts 40.

[0025] The device fixing section 50 has a space inside in which the control board 16 is housed. As shown in Figure 2, the control board 16 is attached to the main body section 10 via the device fixing section 50. Components such as a processor composed of, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and memory are mounted on the control board 16. The control board 16 functions as the control unit of the ultrasonic flowmeter 1 by executing a control program stored in the memory. In this embodiment, the control board 16 is provided with a measurement section that measures the propagation time of ultrasonic waves transmitted and received between a pair of ultrasonic transducers 14, and a calculation section that determines the flow rate of the fluid to be measured based on the signal from this measurement circuit section. 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.

[0026] The device fixing section 50 is provided with multiple clamping sections 52 that clamp the control board 16 from the thickness direction. The control board 16 is fixed to the device fixing section 50 by being clamped by each of the clamping sections 52.

[0027] In this embodiment, a portion of the radial edge of the housing portion 44 is positioned within the internal space of the device fixing portion 50. This makes it possible to shorten the dimensions of the ultrasonic flowmeter 1 in the direction in which the first surface portion 22 and the second surface portion 24 are aligned.

[0028] The housing section 44 is provided with a communication opening 45 located within the internal space of the device fixing section 50, which connects the internal space of the housing section 44 with the internal space of the device fixing section 50. In the ultrasonic flowmeter 1, wiring connecting the ultrasonic transducer 14 and the control board 16 can be routed through the communication opening 45. In the housing section 44, the portion located within the internal space of the device fixing section 50 forms part of the clamping section 52 and also contacts one surface of the control board 16, supporting the control board 16.

[0029] The device fixing portion 50 is provided with a through-hole 19 that penetrates through the thickness direction of the covering member 18 at a position overlapping the terminal 17. In the ultrasonic flow meter 1, wiring extending from outside the ultrasonic flow meter 1 can be connected to the terminal 17 via the through-hole 19.

[0030] As shown in Figure 3, a first partition plate portion 12A and a second partition plate portion 12B are provided inside the flow channel pipe portion 20. As shown in Figure 4, the first partition plate portion 12A and the second partition plate portion 12B are formed in a substantially rectangular plate shape in plan view. The first partition plate portion 12A and the second partition plate portion 12B are formed with a length dimension in the longitudinal direction that is substantially the same as, or shorter than, the longitudinal dimension of the flow channel pipe portion 20. In a plan view, the first partition plate portion 12A and the second partition plate portion 12B are formed with a length dimension that is substantially the same as the distance between the first surface portion 22 and the second surface portion 24 in a direction perpendicular to the longitudinal direction. The first partition plate portion 12A and the second partition plate portion 12B correspond to the "side surface" in this disclosure.

[0031] The first partition plate section 12A and the second partition plate section 12B have their longitudinal directions extending in the direction of the fluid to be measured, and their respective planes are arranged so that they are substantially parallel to the planes of the third surface section 26 and the fourth surface section 28, partitioning the measurement flow path C at equal intervals along the direction in which the third surface section 26 and the fourth surface section 28 are aligned. As a result, multiple divided flow paths D having substantially the same width are formed inside the flow path pipe section 20 in the direction in which the third surface section 26 and the fourth surface section 28 are aligned.

[0032] Multiple rectifier holes 71 are provided in the first partition plate section 12A and the second partition plate section 12B. The rectifier holes 71 are through holes that penetrate the first partition plate section 12A and the second partition plate section 12B along the thickness direction. The multiple rectifier holes 71 are arranged so as to form an approximately isosceles triangle in plan view at approximately the midpoint in the longitudinal direction of the first partition plate section 12A and the second partition plate section 12B. The isosceles triangle formed by the rectifier holes 71 has one side extending along the side between the first partition plate section 12A and the second partition plate section 12B, where the first projection 70 is provided, and the vertex is positioned to project toward the side between the first partition plate section 12A and the second partition plate section 12B, where the second projection 72 is provided. The rectifier holes 71 are provided in the first partition plate portion 12A and the second partition plate portion 12B, for example, by etching. The rectifier holes 71 correspond to the "notches or openings" and "through holes" in this disclosure.

[0033] Figure 5 is an exploded perspective view of the ultrasonic flowmeter 1. In Figure 5, for the sake of explanation, the second member 4 is shown rotated 90 degrees around an axis extending in the Z direction, and the control board 16 is shown by a dashed line. As described above, the main body 10 is formed by connecting the first member 2 and the second member 4.

[0034] The first member 2 is a member that comprises the fourth surface 28 and the first partition plate 12A when the main body 10 is cut by a virtual plane that is substantially parallel to the third surface 26 and the fourth surface 28, and located between the first partition plate 12A and the second partition plate 12B. The second member 4 is a member that comprises the third surface 26 and the second partition plate 12B when the main body 10 is cut by the said virtual plane.

[0035] In this embodiment, the first member 2 comprises a first flow path wall portion 20A, a pair of first transducer holding portions 40A, a first device holding portion 50A, a first partition plate portion 12A, the entirety of the upstream open end portion 30, the entirety of the downstream open end portion 32, and the entirety of the continuous portion 34.

[0036] The first flow path wall portion 20A has a shape that, when the flow path pipe portion 20 is cut along the virtual plane described above, will have a fourth surface portion 28. Specifically, the first flow path wall portion 20A includes a fourth surface portion 28, a first dividing surface portion 22A located on the first surface portion 22 that is on the side of the fourth surface portion 28 that is on the side of the second partition plate portion 12B, and a second dividing surface portion 24A located on the second surface portion 24 that is on the side of the fourth surface portion 28 that is on the side of the second partition plate portion 12B.

[0037] The pair of first transducer holders 40A have a shape that is located on the fourth surface 28 side when the ultrasonic transducer fixing part 40 is cut along the aforementioned virtual plane. The first device holder 50A has a shape that is located on the fourth surface 28 side when the device fixing part 50 is cut along the aforementioned virtual plane.

[0038] The first member 2 is made of a resin material and is formed by integrally molding the entire structure, for example, by injection molding. This integrally forms the first channel wall portion 20A, a pair of first transducer holding portions 40A, the first device holding portion 50A, the first partition plate portion 12A, the entire upstream open end portion 30, the entire downstream open end portion 32, and the entire continuous portion 34. The first member 2 is formed by integrally molding the first channel wall portion 20A and the first partition plate portion 12A, thereby forming a cylindrical portion consisting of the first channel wall portion 20A and the first partition plate portion 12A.

[0039] In this embodiment, the second member 4 comprises a second flow path wall portion 20B, a pair of second transducer holding portions 40B, a second device holding portion 50B, and a second partition plate portion 12B. The second flow path wall portion 20B has a shape that, when the flow path pipe portion 20 is cut along the virtual plane described above, will have a third surface portion 26. Specifically, the second flow path wall portion 20B comprises a first surface portion 22, a second dividing surface portion 22B located on the second surface portion 24, which is on the fourth surface portion 28 side of the first partition plate portion 12A, and a second dividing surface portion 24B located on the second surface portion 24, which is on the third surface portion 26 side of the first partition plate portion 12A.

[0040] The pair of second transducer holders 40B have a shape that is located on the third surface 26 side when the ultrasonic transducer fixing part 40 is cut along the aforementioned virtual plane. The second device holder 50B has a shape that is located on the third surface 26 side when the device fixing part 50 is cut along the aforementioned virtual plane.

[0041] The second member 4 is made of a resin material and is formed by integrally molding the entire structure, for example, by injection molding. This integrally forms the second flow channel wall portion 20B, a pair of second transducer holding portions 40B, a second device holding portion 50B, and a second partition plate portion 12B. The second member 4 is integrally molded with the second flow channel wall portion 20B and the second partition plate portion 12B to form a cylindrical portion consisting of the second flow channel wall portion 20B and the second partition plate portion 12B.

[0042] [1-2-1. Procedure for manufacturing the ultrasonic flowmeter] When the ultrasonic flowmeter 1 is manufactured, the operator fits the pair of ultrasonic transceivers 14 into either the pair of first transceiver holders 40A or the pair of second transceiver holders 40B, and fits the control board 16 into either the first device holder 50A or the second device holder 50B. Next, the operator aligns the first member 2 and the second member 4 such that the first flow path wall portion 20A and the second flow path wall portion 20B form the flow path tube portion 20, the pair of first transceiver holders 40A and the pair of second transceiver holders 40B form the pair of ultrasonic transceiver fixing portions 40, and the first device holder 50A and the second device holder 50B form the device fixing portion 50. After that, the operator performs, for example, thermal welding, ultrasonic welding, or high-frequency welding on the contact portions of the first member 2 and the second member 4. As a result, the first member 2 and the second member 4 are connected, and the ultrasonic flowmeter 1 is formed.

[0043] Thus, in the ultrasonic flowmeter 1, compared with the case where, for example, the flow path tube portion 20, the ultrasonic transceiver fixing portion 40, and the device fixing portion 50 are formed separately and then connected, variations and displacements in the positions of the respective parts due to assembly are suppressed. Therefore, in the ultrasonic flowmeter 1, it is possible to suppress a decrease in measurement accuracy. In addition, in the ultrasonic flowmeter 1, it is possible to reduce the number of parts, reduce the man-hours associated with manufacturing, and suppress the complication of the structure.

[0044] [1-2-2. Operation of the ultrasonic flowmeter] Regarding the ultrasonic flowmeter 1 configured as described above, its operation will be described below. As shown in FIG. 2, when the fluid to be measured flows inside the measurement flow path C, the fluid to be measured is divided by each of the partition plates 12 and flows through each of the divided flow paths 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 arranged becomes substantially uniform.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] [1-3. Effects, etc.] As described above, in the present embodiment, the ultrasonic flowmeter 1 includes a first member 2 and a second member 4 connected to the first member 2. The first member 2 is integrally provided with a first flow path wall portion 20A, a first ultrasonic transducer holding portion 40A, and a first partition plate portion 12A, and the second member 4 is integrally provided with a second flow path wall portion 20B, a second ultrasonic transducer holding portion 40B, and a second partition plate portion 12B. The first flow path wall portion 20A and the second flow path wall portion 20B are connected by connecting the second member 4 to the first member 2, and form a measurement flow path C with a rectangular cross-section through which the fluid to be measured flows. The first ultrasonic transducer holding portion 40A and the second ultrasonic transducer holding portion 40B are connected by connecting the second member 4 to the first member 2, and form an ultrasonic transducer fixing portion 40 to which a pair of ultrasonic transducers 14 arranged upstream and downstream of the measurement flow path C are attached. The first partition plate portion 12A and the second partition plate portion 12B are arranged substantially parallel to the flow direction of the fluid to be measured by connecting the second member 4 to the first member 2, and the measurement flow path C is formed into a plurality of divided flow paths.

[0050] Thereby, in the ultrasonic flowmeter 1, the number of parts and the man-hours involved in production can be reduced. In addition, in the ultrasonic flowmeter 1, it is possible to eliminate the occurrence of a deviation in the ultrasonic propagation distance due to the gap at the joint between the ultrasonic transducer fixing portion 40 and the flow path pipe portion 20 and the variation in the fixing positions of the pair of ultrasonic transducers 14 generated during the assembly of the ultrasonic transducer fixing portion 40 and the flow path pipe portion 20. For this reason, in the ultrasonic flowmeter 1, highly accurate flow measurement can be realized.

[0051] As in the present embodiment, the first member 2 is integrally provided with a first device holding portion 50A, and the second member 4 is integrally provided with a second device holding portion 50B. The first device holding portion 50A and the second device holding portion 50B are connected by connecting the second member 4 to the first member 2, and may form a device fixing portion 50 to which a control board 16 for measuring the propagation time of ultrasonic waves from one ultrasonic transducer 14 to the other ultrasonic transducer 14 is attached. Thereby, in the ultrasonic flowmeter 1, the number of parts and the man-hours involved in production can be reduced.

[0052] As in this embodiment, each of the ultrasonic transducers 14 is provided on the first surface of the measurement channel C. The first partition plate section 12A and the second partition plate section 12B are provided with a short-circuit path S, which is a region formed by the normal propagation paths U1 and U2 and the first surface, where 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 flow straightening 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 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.

[0053] In this embodiment, when the ultrasonic flowmeter 1 is manufactured, a first member 2, which is at least partially formed in a cylindrical shape, and a second member 4, which is at least partially formed in a cylindrical shape, are each provided with a flow straightening hole 71 that penetrates in the thickness direction of the plate on their respective sides, i.e., the first partition plate portion 12A and the second partition plate portion 12B. When the ultrasonic flowmeter 1 is manufactured, the first member 2 and the second member 4 are connected so that the first partition plate portion 12A and the second partition plate portion 12B are facing each other, thereby forming a tubular flow path section 20 in which the first partition plate portion 12A and the second partition plate portion 12B are each arranged. As a result, in the ultrasonic flowmeter 1, the first partition plate portion 12A and the second partition plate portion 12B, which are integrally provided in the flow path section 20 and located inside the flow path section 20, are each provided with a flow straightening hole 71 to reduce the interference effect of diffracted waves passing through the short-circuit path S. Therefore, the ultrasonic flowmeter 1 can improve the accuracy of flow measurement while reducing the number of parts and the man-hours required for manufacturing.

[0054] (Other Embodiments) As described above, Embodiment 1 has been explained as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this 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 Embodiment 1 above. Therefore, other embodiments are described below as examples.

[0055] In the ultrasonic flowmeter 1, the device fixing part 50 may be formed separately from the first member 2 and the second member 4. In this case, the device fixing part 50 may be formed as a single integrated unit.

[0056] In the ultrasonic flowmeter 1, the first member 2 may be provided with a plurality of first partition plate portions 12A, and the second member 4 may be provided with a plurality of second partition plate portions 12B.

[0057] In the above-described embodiment, the first member 2 comprises the entirety of the upstream open end 30, the entirety of the downstream open end 32, and the entirety of the continuous portion 34. However, the invention is not limited to this, and at least one of the upstream open end 30 and the downstream open end 32 may be divided and each be integrally provided on the first member 2 and the second member 4, respectively.

[0058] In the above-described embodiment, the first partition plate section 12A and the second partition plate section 12B are provided with rectifying holes 71. However, the invention is not limited to this, and the partition plate 12 and the partition plate section 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 first partition plate section 12A and the second partition plate section 12B may have punched holes or a mesh structure with a large number of mechanically made holes.

[0059] 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 of the first partition plate portion 12A and the second partition plate portion 12B. 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.

[0060] 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.

[0061] (Note) The above description of embodiments discloses the following technology.

[0062] (Technical 1) An ultrasonic flow meter comprising a first member and a second member connected to the first member, wherein the first member is integrally provided with a first flow path wall, a first transducer holder, and a first partition plate, and the second member is integrally provided with a second flow path wall, a second transducer holder, and a second partition plate, and the first flow path wall and the second flow path wall are connected by the second member being connected to the first member, forming a rectangular cross-section measuring flow path through which the fluid to be measured flows, the first transducer holder and the second transducer holder are connected by the second member being connected to the first member, forming an ultrasonic transducer fixing section to which a pair of ultrasonic transducers arranged upstream and downstream of the measuring flow path are attached, and the first partition plate and the second partition plate are arranged substantially parallel to the flow direction of the fluid to be measured by the second member being connected to the first member, thereby dividing the measuring flow path into multiple divided flow paths. According to this, ultrasonic flow meters can reduce the number of parts and the man-hours required for their manufacture.

[0063] (Technical 2) The ultrasonic flow meter according to claim 1, wherein the first member is integrally provided with a first device holding portion, the second member is integrally provided with a second device holding portion, the first device holding portion and the second device holding portion are connected by the second member being connected to the first member, and a device fixing portion is formed to which a measuring device for measuring the propagation time of ultrasonic waves from one ultrasonic transducer to the other ultrasonic transducer is attached. With this, the ultrasonic flow meter can reduce the number of parts and the man-hours required for manufacturing.

[0064] (Technical 3) Each of the ultrasonic transducers is provided on the first surface of the measurement channel, and each of the first partition plate and the second partition plate is provided with a short-circuit path that short-circuits 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 a region formed by the normal propagation path and the first surface, and the short-circuit path is provided with a notch or opening that connects the divided channels, and the notch and opening are not provided in the first partition plate and the second partition plate in regions different from the short-circuit path, as described in claim 1 or claim 2.

[0065] (Technical 4) A method for manufacturing an ultrasonic flow meter, comprising a first member formed in a cylindrical shape in at least a portion thereof, and a second member formed in a cylindrical shape in at least a portion thereof, wherein through holes penetrating in the thickness direction are provided on each side surface of the first member and the second member, with each of the side surfaces facing the other, thereby forming a tubular section in which each of the side surfaces is positioned internally. According to this method, in an ultrasonic flow meter, through holes can be provided on each of the side surfaces integrally provided with the tubular section to reduce the interference effect of diffracted waves passing through the short-circuit path S. Therefore, in the ultrasonic flow meter 1, the accuracy of flow measurement can be improved while reducing the number of parts and the man-hours required for manufacturing.

[0066] 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.

[0067] 1 Ultrasonic flowmeter 2 First member 4 Second member 10 Main body part 12 Partition plate 12A First partition part 12B Second partition part 14 Sonic wave transducer 16 Control board 17 Terminal 18 Covering member 19 Insertion hole 20 Channel pipe part 20 Channel pipe part 20A First channel wall part 20B Second channel wall 21 Opening 22 First surface 22A First dividing surface 22B Second dividing surface 23 Communication hole 24 Second dividing surface 24A Second dividing surface 24B Second dividing surface 26 Third surface 28 Fourth surface 30 Upstream open end 32 Downstream open end 34 Continuous section 36 Outflow section 40 Sound wave transducer fixing part 40A First transducer holding part 40B Second transducer holder 42 Conduit 44 Housing 45 Communication opening 50 Device fixing part 50A First device holder 50B Second device holder 52 Clamping part 70 First projection 71 Rectification hole 72 Second projection C Measurement channel D Divided channel S Short circuit path U1 Normal propagation path U2 Normal propagation path

Claims

First member and A second member connected to the first member, Equipped with, The first member includes, The first channel wall and The first transducer holding section, The first partition plate section, It is provided as a single unit. The second member includes, The second channel wall and The second transducer holding section, The second partition plate section, It is provided as a single unit. The first channel wall and the second channel wall are connected by the second member being connected to the first member, forming a rectangular cross-sectional measurement channel through which the fluid to be measured flows. The first transducer holder and the second transducer holder are connected by the second member being connected to the first member, forming an ultrasonic transducer fixing section to which a pair of ultrasonic transducers, which are arranged upstream and downstream of the measurement channel, are attached. The first partition plate and the second partition plate are arranged substantially parallel to the flow direction of the fluid to be measured by connecting the second member to the first member, thereby dividing the measurement channel into multiple divided channels. Ultrasonic flow meter. 　 The first member is integrally provided with a first device holding portion. The second member is integrally provided with a second device holding portion. The first device holding portion and the second device holding portion are connected by the second member being connected to the first member, forming a device fixing portion to which a measuring device for measuring the propagation time of ultrasonic waves from one ultrasonic transducer to the other ultrasonic transducer is attached. The ultrasonic flow meter according to claim 1. 　 Each of the ultrasonic transducers is provided on the first surface of the measurement channel, Each of the first partition plate section and the second partition plate section is provided with a short-circuit path that short-circuits the normal propagation path through which ultrasonic waves propagate from one ultrasonic transducer to the other ultrasonic transducer, and is a region formed by the normal propagation path and the first surface. The short-circuit path is provided with a notch or opening that connects the divided flow paths, In the first partition plate section and the second partition plate section, the notches and openings are not provided in areas different from the short-circuit path. The ultrasonic flow meter according to claim 1 or claim 2. 　 A first member, at least a portion of which is formed in a cylindrical shape, and a second member, at least a portion of which is formed in a cylindrical shape. Each side of the plate is provided with a through hole that penetrates in the direction of the plate thickness. The first member and the second member are connected with their respective side surfaces facing each other, and each of the side surfaces forms a tubular portion that is positioned inside. A method for manufacturing an ultrasonic flow meter.

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