Vibration transmission member, and vibration transducer, measuring instrument, and concentration meter using the same

Abstract

To provide a vibration propagation member operating in conjunction with vibrating means, a vibration transducer using the same, and a measuring device using the same.SOLUTION: A vibration propagation member 2 that operates in conjunction with one surface of the vibrating means 1. The vibration propagation member 2 is formed with a top plate 3, a side wall 4, and a vertical partition 5 arranged substantially perpendicular to the top plate 3. The vibration propagation member uses at least a first vibration (f1) that vibrates in the same direction as the vibration propagation direction and a second vibration (f2) generated in the membrane structure formed by the top plate 3 and the vertical partition 5.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a vibration propagation member that operates by being joined to a vibration means, and to a measuring instrument using the vibration propagation member, such as a vibration transducer, a flow meter, a flow velocity meter, or a concentration meter. [Background technology]

[0002] Conventionally, this type of vibration propagation member has been used as a disk made of a mixture of epoxy resin and minute glass spheres. This disk has been bonded to a piezoelectric body and used as an ultrasonic transmitter / receiver or ultrasonic measuring instrument (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-125804 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the ultrasonic transducer using the conventional vibration propagation member, it is difficult to ensure stable operation when the fluid to be measured is a corrosive fluid, or in a high-temperature, high-humidity environment or an ultra-high-temperature environment.

[0005] Furthermore, the design of the vibration propagation member has a low degree of freedom, and can only be carried out in terms of thickness, outer dimensions, etc. The degree of freedom in frequency design is also low.

[0006] The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object to provide a vibration propagation member that can operate stably even when the fluid to be measured is a corrosive fluid or in a high-temperature, high-humidity environment, and that has a high degree of freedom in design. [Means for solving the problem]

[0007] Conventionally, the vibration means and the vibration propagation member that is joined to one surface of the vibration means have been designed by selecting the material taking into consideration the density, sound speed, etc. of the vibration propagation member according to the medium that propagates the vibration, and by designing the thickness, outer diameter, etc. of the vibration propagation member. In addition, because it is made of a single material, it has been difficult to control the local characteristics of the vibration propagation member. [Effects of the Invention]

[0008] The vibration propagation member of the present invention is composed of a top plate, side walls, a bottom plate, and vertical partition walls arranged approximately perpendicular to the top and bottom plates. By adjusting the thickness of the vibration propagation member, which is a component of the vibration propagation member, it is possible to control a first vibration (f1) that vibrates in the same direction as the vibration propagation direction, and in addition, it is possible to individually control a second vibration (f2) excited by a membrane structure formed by the thickness of the vertical partition walls, the distance between the vertical partition walls, the thickness of the top plate, etc. As a result, the vibration propagation member of the present invention has a high degree of design freedom, and a vibration transducer having this vibration propagation member attached to a piezoelectric body can freely control the frequency of vibrations to be transmitted and received by adjusting the thickness of the vibration propagation member as well as the membrane structure formed by the thickness of the vertical partition walls, the distance between the vertical partition walls, the thickness of the top plate, etc.

[0009] Furthermore, the vibration propagation member of the present invention is capable of stable operation even when exposed to a corrosive environment or a high-temperature, high-humidity environment by making the space formed by the top plate, bottom plate, and vertical partition into an airtight space. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a vibration propagation member provided on one surface of the vibration means according to the first embodiment; [Figure 2] (a) is a cross-sectional view of the vibration propagation member according to the first embodiment; (b) is a cross-sectional view of the vibration propagation member according to the first embodiment taken along line X; [Figure 3] 1 is a perspective view showing a manufacturing procedure of a vibration propagation member according to the first embodiment; [Figure 4] 1 is a cross-sectional view of a vibration transducer according to the first embodiment. [Figure 5]1 is a cross-sectional view showing a manufacturing procedure of the vibration transducer according to the first embodiment; [Figure 6] FIG. 10 is a diagram showing the results of measuring the resonance frequency of the vibration propagation member according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing the influence of the thickness of the vibration propagation member on the resonance frequency in the first embodiment. [Figure 8] FIG. 10 is a diagram showing the influence of the distance between vertical partition walls on sensitivity in the first embodiment. [Figure 9] FIG. 10 is a diagram showing a comparison of the difference between the resonant frequencies f1 and f2 and the received waveform in the first embodiment. [Figure 10] Schematic diagram of a flow meter and a flow velocity meter according to the first embodiment [Figure 11] Schematic diagram of a concentration meter according to the first embodiment [Figure 12] 10 is a cross-sectional view of a vibration propagation member provided on one surface of the vibration means in the second embodiment. [Figure 13] (a) is a cross-sectional view of a vibration propagation member according to a second embodiment; (b) is a cross-sectional view of the vibration propagation member according to the second embodiment taken along line X; [Figure 14] 10 is a cross-sectional view illustrating the definitions of the internal pressure P1 and the pressure P2 of the vibration propagation medium in the second embodiment. [Figure 15] FIG. 10 is a partially enlarged cross-sectional view of a vibration propagation member according to a second embodiment. [Figure 16] FIG. 10 is a partially enlarged cross-sectional view of a vibration propagation member according to a second embodiment. [Figure 17] FIG. 10 is a partially enlarged cross-sectional view of a vibration propagation member according to a second embodiment. [Figure 18] FIG. 10 is a partially enlarged cross-sectional view of a vibration propagation member according to a second embodiment. [Figure 19] 10 is a partially enlarged cross-sectional view including a side wall and a vertical partition wall of a vibration propagation member according to a second embodiment. [Figure 20] 10A and 10B are perspective views showing a manufacturing procedure of the vibration propagation member according to the second embodiment; [Figure 21] 10 is a cross-sectional view of a vibration propagation member provided on one surface of the vibration means in the third embodiment. [Figure 22] (a) is a cross-sectional view of a vibration propagation member according to a third embodiment; (b) is a cross-sectional view of the vibration propagation member according to the third embodiment taken along line X; [Figure 23] 11 is a perspective view showing a manufacturing procedure of the vibration propagation member according to the third embodiment. [Figure 24] Cross-sectional view of a vibration transducer according to a fourth embodiment. [Figure 25] 10A and 10B are cross-sectional views showing a manufacturing procedure for the vibration transducer according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Findings that formed the basis of this disclosure) At the time the inventors came up with the idea for this disclosure, in order to measure the flow velocity, flow rate, and concentration of the measured fluid, which was a combustible gas or dry air such as air, it was necessary to efficiently propagate vibrations such as ultrasonic waves to the measured fluid, and therefore it was necessary to control the physical properties of the vibration propagation member interposed between the measured fluid and the piezoelectric body used as one of the vibration means.

[0012] The physical interpretation of the vibration transmission member described above is as follows.

[0013] First, the definition of acoustic impedance, which is the product of density and sound velocity, indicates the momentum of the material that constitutes the infinitesimal unit element of that material. In other words, if the momentum of the material that constitutes the infinitesimal unit element is ΔP, the mass is ΔM, and the velocity is V, then from the definition of momentum, ΔP (momentum) = ΔM × V (acoustic impedance) (1) It can be seen that the acoustic impedance is the momentum of the material that constitutes the minute unit element.

[0014] Therefore, for efficient energy transmission from one material (ultrasonic wave source) to an adjacent material, it is desirable that the acoustic impedances are close to each other.

[0015] Based on these, the phenomenon that occurs in the acoustic matching layer will be described.

[0016] In general, the speed of sound in a material is V=(κ / ρ) 1 / 2...(2) where κ is the bulk modulus and ρ is the density. In other words, since the speed of sound in a material is uniquely determined by the bulk modulus and density, it is clear that it is difficult to intentionally control the speed of sound.

[0017] Therefore, reducing the density is effective in reducing the acoustic impedance.

[0018] Such vibration propagation members have been designed by reducing the density and by determining the thickness, outer diameter, and other dimensions based on the sound speed in the propagation direction.Moreover, most of the constituent materials used are single materials or nearly uniform composite materials, making it difficult to partially control the characteristics of the vibration propagation member.

[0019] Furthermore, in the conventional configuration, when a high-temperature, high-humidity gas is assumed as the vibration propagation medium, moisture gets into the holes or through-holes in the vibration propagation member, and the density of the vibration propagation member appears to increase, which increases the acoustic impedance of the acoustic matching body and reduces the efficiency of vibration propagation to the vibration propagation medium. As a result, there is a problem that the performance of measuring instruments using this, such as flow meters and concentration meters, is reduced, or in the worst case, measurements become impossible.

[0020] The inventors of the present application have found such problems in the prior art and have come to constitute the subject of the present disclosure in order to solve the problems.

[0021] The present disclosure provides a vibration propagation member that has a high degree of freedom in design and is capable of propagating vibrations stably and with high precision for a long period of time, even when the vibration propagation medium is a high-temperature, high-humidity fluid. It also provides a vibration transducer formed by bonding this vibration propagation member to one surface of a vibrating means, and a measuring instrument using the same, such as a flow meter, a flow velocity meter, or a concentration meter.

[0022] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0023] The accompanying drawings and the embodiments described below are provided to enable those skilled in the art to fully understand the present disclosure, and each illustrates an example of the present disclosure, and are not intended to limit the subject matter described in the claims.

[0024] In the following embodiments, for convenience, three axes, the X-axis, the Y-axis, and the Z-axis, are shown in the drawings showing the shapes of the components of the present disclosure, and the X-axis, the Y-axis, and the Z-axis are used in the description as necessary. In the following embodiments, for convenience, when the ultrasonic transmitter / receiver is disposed in the orientation shown in FIG. 1, the direction from left to right on the paper surface of FIG. 1 is the X-axis positive direction, the direction from bottom to top on the paper surface of FIG. 1 is the Z-axis positive direction, and the direction from front to back on the paper surface of FIG. 1 is the Y-axis positive direction. The size of the component parallel to the Z-axis is sometimes referred to as "thickness," and the Z-axis positive direction is sometimes referred to as "up" or "upper," and the Z-axis negative direction is sometimes referred to as "lower" or "lower." The descriptions using the X-axis, Y-axis, Z-axis, top, and bottom are merely for convenience to facilitate understanding of the present disclosure, and the terms "up" and "down" are relative terms that change depending on the installation orientation of the ultrasonic transmitter / receiver of the present disclosure. Therefore, the present disclosure is not limited by the descriptions using these in the following embodiments.

[0025] (Embodiment 1) 1 to 11, the vibration propagation member of the first embodiment, a vibration transducer using this vibration propagation member, and a flow meter, a flow meter, and a concentration meter using this vibration transducer will be described below.

[0026] [1-1. Vibration transmission components] [1-1-1. Configuration of vibration transmission components] FIG. 1 is a cross-sectional view schematically illustrating an example of a configuration in which a vibration propagation member 2 according to the first embodiment is provided on one surface of vibration means 1. FIG. 1 shows a cross-sectional view (cross-sectional view on the XZ plane) of the vibration propagation member 2 cut in the thickness direction (parallel to the Z axis). As shown in FIG. 1, the vibration propagation member 2 is surface-bonded to one surface of the vibration means 1 and vibrates in response to the vibration of the vibration means 1. The vibration propagation member 2 is composed of a top plate 3, a side wall 4, and a vertical partition wall 5 formed approximately perpendicular to the top plate 3. The space formed by the top plate 3, the vertical partition wall 5, and the vibration means 1 can be an enclosed space 6. Depending on the purpose, when the enclosed space is used and the medium that propagates the vibration does not contain liquid components such as high temperature and high humidity, a through-hole can be formed in the vertical partition wall 5 to form a space similar to the space that propagates the vibration.

[0027] Next, the internal structure of the vibration propagation member 2 will be described with reference to Fig. 2. Fig. 2 is a cross-sectional view showing an example of the configuration of the vibration propagation member 2 according to the first embodiment.

[0028] 2(a) shows a cross-sectional view (cross-sectional view in the XZ plane) of the vibration propagation member 2 cut in the thickness direction (parallel to the Z axis). FIG. 2(b) shows a cross-sectional view taken along line II-II in FIG. 2(a), i.e., a cross-sectional view (cross-sectional view in the XY plane) of the vibration propagation member 2 cut in a direction perpendicular to the thickness direction (parallel to the XY plane). T in the figure indicates the thickness of the vibration transmission member 2 (parallel to the Z axis) indicated by the arrow. Note that, as shown in FIG. 2(b), the cross-section of the vibration propagation member 2 in the direction perpendicular to the thickness direction has, for example, a honeycomb-shaped vertical partition wall 5.

[0029] [1-1-2. Manufacturing procedure for vibration transmission components] Next, a manufacturing procedure for the vibration propagation member 2 will be described with reference to FIG.

[0030] 3 is a perspective view showing a manufacturing procedure for the vibration propagation member 2 in the embodiment 1. The manufacturing process for the vibration propagation member 2 proceeds in the order of (a), (b), (c), and (d) shown in FIG.

[0031] As shown in Figure 3(a), first, a metal plate 10 large enough to extract multiple pattern structures and multiple metal plates 10 from which individual pattern structures can be extracted are prepared. Figure 3(a) shows one metal plate 10. Next, as shown in Figure 3(b), metal plate 11 is patterned into a circular shape to form metal plate 10 as top plate 3, and metal plate 12 is patterned to form side walls 4 and vertical partition walls 5 of vibration propagation member 2; these are produced separately or simultaneously.

[0032] For patterning the metal plate 10, for example, a punching process using a press of the metal plate 10, a photolithographic etching process, a laser process, or a process using a discharge wire can be used. Note that in the present disclosure, an example is shown in which the metal plate 11 patterned into a circular shape to form the top plate 3 and the patterned metal plate 12 are formed so that their outer shapes are circular (disk-shaped) when viewed from above (when viewed parallel to the Z axis). However, this is merely an example, and the outer shapes of the top plate 3 and the patterned metal plate 12 shown in the present disclosure are not limited to circular (disk-shaped) shapes, but may also be elliptical or polygonal.

[0033] Next, as shown in Fig. 3(c), a plurality of patterned metal plates 12 and the top plate 3 are stacked in order while being positioned. 12 are stacked. Next, a top plate 3 is stacked on the top surface of the multiple patterned metal plates 12 (the surface of the patterned metal plate 12 located at the farthest end in the positive direction of the Z axis facing the positive Z axis). Next, the patterned metal plates are bonded together by diffusion bonding, an example of direct bonding, under heat and pressure in a vacuum environment to form a single material. For example, in the case of stainless steel, the melting point is approximately 1500°C, while the temperature during diffusion bonding is approximately 1000°C. Therefore, if the multiple stacked metal plates 12 and the top plate 3 are made of stainless steel, heating them to this temperature in a vacuum and applying pressure can diffuse the atoms at the bonding interface and bond them without melting the base material. Because diffusion bonding requires flatness, depending on the processing method shown in FIG. 3(c), post-processing to remove burrs and deformations from the circularly patterned metal plate 11 and the patterned metal plate 12 may be required after the process shown in FIG. 3(b).

[0034] In addition, fusion welding, which involves partially melting the base material, is also considered a direct joining method. In this case, it is possible to join multiple metal plates together by heating stainless steel to around 1500°C. As a method for joining metal plates together, it is also possible to use epoxy resin or cyanoacrylate adhesives, which are considered to be bonding materials between metal plates. In addition, when inorganic materials are selected as bonding materials, brazing is also possible.

[0035] By the above manufacturing procedure, it is possible to produce the vibration propagation member 2 of the present embodiment 1, in which each metal patterning is bonded by the bonding method exemplified in this embodiment, as shown in Fig. 3(d). Note that in this embodiment, an example has been shown in which the vibration propagation member is formed to have a cylindrical outer shape, but this is merely an example, and the shape of the vibration propagation member shown in this disclosure is not limited to a cylindrical shape, and may be an elliptical cylinder or a polygonal cylinder.

[0036] [1-2. Vibration Transducer] [1-2-1. Vibration Transducer Configuration] FIG. 4 is a cross-sectional view schematically showing an example of the configuration of the vibration transmitter / receiver 14 according to the first embodiment. FIG. 4 shows a cross-sectional view (cross-sectional view in the XZ plane) of the vibration transmitter / receiver 14 cut in the thickness direction (parallel to the Z axis).

[0037] As shown in Figure 4, the vibration transmitter / receiver 14 is composed of a vibration means 1 having one electrode 15 and the other electrode 16, a vibration propagation member 2 joined to one surface of the vibration means 1, and lead wires 18 and 19 electrically connected to the electrodes 15 and 16 of the vibration means 1.

[0038] [1-2-2. Vibration Transducer Manufacturing Procedure] Next, a manufacturing procedure for the vibration transmitter / receiver 14 will be described with reference to FIG.

[0039] 5 is a cross-sectional view showing a manufacturing procedure for the vibration transmitter / receiver 14 according to the embodiment 1. The manufacturing process for the vibration transmitter / receiver 14 proceeds in the order of (a), (b), (c), and (d) shown in FIG.

[0040] FIG. 5(a) shows a cross-sectional view of the vibration propagation member 2 described in the first embodiment, and FIG. 5(b) shows a cross-section of the vibration means 1 having one electrode 15 and the other electrode 16, with a bonding material 17 applied to the surface of one electrode 15. This bonding material 17 can be bonded with a general adhesive such as an epoxy adhesive, a phenolic adhesive, or a cyanoacrylate adhesive. The bonding material is not particularly limited as long as it is a thermosetting resin such as an epoxy resin, a phenolic resin, a polyester resin, or a melamine resin. Therefore, even if the resin is a thermoplastic resin, it can be used as long as the glass point transition temperature is below 70°C, which is the high temperature used.

[0041] Fig. 5(c) shows a state in which the vibration means 1 and the vibration propagation member 2 are joined by chemically reacting these joined bodies 17. Fig. 5(d) shows a state in which one electrode 15 and the other electrode 16 provided on the vibration means 1 are electrically joined to lead wires 18 and 19 by soldering, and the vibration transmitter / receiver 14 according to the first embodiment is completed.

[0042] [1-2-3. Vibration Transducer Operation, Action and Effects] The operation of the vibration transducer 14 will now be described. As an example of the vibration means 1, a piezoelectric vibrator is used.

[0043] In the vibration transmitter / receiver 14, a sine wave or square wave electric pulse of a predetermined frequency is applied via one lead wire 18 and the other lead wire 19 of the piezoelectric vibrator used as the vibration means 1, and this electric pulse vibrates the piezoelectric vibrator, which is the vibration means 1, and this vibration is transmitted to the top plate 3 via the vertical partitions 5 of the vibration propagation member 2. At this time, by changing the shape of the vibration propagation member 2, the shape of the top plate 3 of the vibration propagation member 2 and the vertical partitions 5 formed in the internal space of the side walls 4, the thickness of the vertical partitions 5, the distance between the vertical partitions 5, the thickness of the side walls 4, and the thickness T of the vibration propagation member 2, the vibration transmitted to the vibration propagation member 2 resonates greatly, and it becomes possible to efficiently transmit the vibration to the vibration propagation medium such as gas or liquid to which the vibration is to be transmitted. As a result, it is possible to control the characteristics of the vibration transmitter / receiver 14 with many design parameters (shape of the vibration propagation member 2, shape of the vertical partitions 5, thickness of the vertical partitions 5, distance between the vertical partitions 5, thickness of the side walls 4, thickness T of the vibration propagation member 2, etc.), which shows that there is a high degree of freedom in designing the vibration propagation member 2.

[0044] [1-2-4. Correlation between vibration transmission member structure and vibration transducer characteristics] The correlation between the vibration propagation member structure and the vibration transducer characteristics will be described with reference to FIGS.

[0045] FIG. 6(a) is a cross-sectional view of the vibration analysis state of the vibration transducer 14 according to the first embodiment of the present invention, and FIG. 6(b) shows the analysis results. The vibration analysis method will be briefly explained using FIG. 6(a). With the vibration means 1 vibrating at a predetermined frequency, a laser beam 21 is irradiated from the sensor head 20 onto the vibration propagation member 2, and the frequency change of the laser beam 22 reflected from the vibration propagation member 2 is detected, thereby measuring the vibration velocity and displacement (not shown in the figure) of the vibration transducer 14. FIG. 6(b) shows the frequency and vibration velocity of the vibration propagation member 2 as the analysis results.

[0046] From this result, it can be seen that there are multiple vibrations of the vibration propagation member 2 in response to the vibration of the vibration means 1. When vibrations in the same direction as the vibration propagation direction are extracted from these vibrations, the analysis results described below show that the first vibration f1 indicates a vibration form in the thickness direction of the vibration propagation member 2, and the second vibration f2 indicates a natural vibration induced by the membrane structure 7 formed by the distance between the vertical partition walls 5 and the thickness of the top plate 3 in response to the vibration of the vibration means 1. Although other vibration peaks were observed, these were vibration forms different from the vibration propagation direction transmitted to the propagation medium, so details will be omitted here.

[0047] Figure 7 shows the effect of the thickness of the vibration propagation member on the resonance frequencies of the first vibration f1 and the second vibration f2. The resonance frequency of the first vibration f1 changes depending on the thickness of the vibration propagation member, suggesting that this is due to the vibration mode in the vibration propagation direction, and that the resonance frequency can be controlled by adjusting the thickness of the vibration propagation member. In contrast, the resonance frequency of the second vibration f2 does not change even with the thickness T of the vibration propagation member.

[0048] FIG. 8 shows the correlation between the distance between the vertical partition walls 5 and the sensitivity, which indicates the efficiency of vibration propagation to the vibration propagation medium. The second vibration f2 exhibits a maximum vibration propagation efficiency depending on the distance between the vertical partition walls 5. This is a natural vibration induced in the membrane structure 7 formed by the distance between the vertical partition walls 5 and the thickness of the top plate 3 with respect to the vibration frequency of the piezoelectric body used as the vibration means 1. It is presumed that by changing the distance between the vertical partition walls 5, the membrane structure 7 resonates strongly with the vibration of the vibration means 1, resulting in a maximum sensitivity. In other words, the resonance frequency of this second vibration f2 can be controlled by controlling the distance between the vertical partition walls 5, the thickness of the top plate, the thickness of the vertical partition wall, and other factors in the membrane structure 7 formed by the vertical partition walls 5 and the top plate 3.

[0049] As described above, in the vibration propagation member of this embodiment, the first vibration f1 and the second vibration f2 have different vibration forms, and can be controlled independently by changing different structural factors of the vibration transmitter / receiver 14. Next, we will show that by utilizing this characteristic and combining these two vibrations (the first vibration f1 and the second vibration f2), the vibration propagation waveform can be controlled.

[0050] Figure 9(a) shows a cross-sectional view of the vibration propagation waveform measurement method. When a transmission pulse wave is transmitted from a transmission wave generator to vibration transducer 14a, the vibration means of vibration transducer 14a vibrates at a frequency corresponding to the transmission pulse, and the vibration propagation member resonates with this vibration, amplifying the vibration and propagating it through the vibration propagation medium. When the propagated vibration reaches vibration transducer 14b, which is placed a certain distance away, the vibration propagation member of vibration transducer 14b resonates, and this vibration vibrates the vibration means, which converts it into an electrical signal and the vibration propagated through the vibration propagation medium can be measured by the received wave measuring instrument.

[0051] Figure 9(b) shows a received waveform obtained using the vibration waveform measurement method of Figure 9(a). This shows the received waveform obtained when the structure of the vibration propagation member 2 of the present invention is controlled to set the first vibration f1 to 485 kHz and the second vibration f2 to 515 kHz, resulting in a resonant frequency difference (f2-f1) of 30 kHz. Figure 9(c) shows the received waveform obtained when the first vibration f1 is 460 kHz and the second vibration f2 is 540 kHz, resulting in a resonant frequency difference of 80 kHz. In various measurement systems, if a large waveform (sensitivity) is required, a design that produces the received wave shown in Figure 9(b) can be used. If a waveform with a smaller wave number is required, a design that produces the received wave shown in Figure 9(c) can be used. By assuming the received waveform appropriate for the required system and changing the structure of the vibration propagation member 2, it is possible to accommodate various measurement systems. The resonant frequencies of the first vibration f1 and the second vibration f2 can be controlled independently by using the vibration propagation member 2 of this embodiment, and therefore, by using the vibration propagation member 2 of this embodiment, it becomes possible to design the vibration propagation waveform relatively freely.

[0052] [1-2-5. Effects and Actions] As described above, in this embodiment, the vibration transmitter / receiver 14 comprises a vibration means 1 and a vibration propagation member 2 that operates by being joined to one surface of the vibration means 1, and the vibration propagation member 2 is formed by a top plate 3, a side wall 4, and a vertical partition 5 arranged approximately perpendicular to the top plate 3.By adjusting the thickness of the vibration propagation member 2, which is a component of the vibration propagation member 2, the first vibration (f1) that vibrates in the same direction as the vibration propagation direction can be controlled, and in addition, the second vibration (f2) excited by the membrane structure 7 formed by the thickness of the vertical partition, the distance between the vertical partitions, the thickness of the top plate, etc. can be individually controlled.When a vibration transmitter / receiver 14 is used with a vibration means attached, it is possible to freely control the frequency of the vibrations that are transmitted and received, and a vibration propagation member 2 with a high degree of design freedom can be obtained.

[0053] Furthermore, by forming the space formed by the top plate 3, the vertical partition wall 5, and the vibration means 1 into an enclosed space 6, stable operation is possible even when exposed to a corrosive environment or a high-temperature, high-humidity environment.

[0054] [1-3. Flow meter or flow meter] [1-3-1. Configuration of a velocity meter or flow meter] Next, the flow meter of this embodiment will be described with reference to Fig. 10. Note that although flow meter 23 will be described below, this flow meter 23 can be replaced with flow velocity meter 24. In that case, the flow rate in the following description should be read as flow velocity. Alternatively, the measuring instrument shown in Fig. 10 may be a measuring instrument that can measure both flow rate and flow velocity.

[0055] FIG. 10 is a block diagram schematically showing an example of the configuration of flowmeter 23 according to the first embodiment.

[0056] In the flow meter 23 of this embodiment 1, the ultrasonic range is exemplified as the vibration frequency range to be transmitted and received, the vibration transmitter / receiver is an ultrasonic transmitter / receiver that transmits and receives ultrasonic waves, and the flow meter is called an ultrasonic flow meter.

[0057] As shown in Fig. 10, flowmeter 23 of this embodiment is configured such that a pair of ultrasonic transmitter / receivers 26, 27 using the vibration transmitter / receiver configuration shown in Embodiment 1 are arranged facing each other upstream and downstream of flow path 25 through which a fluid flows. The direction of fluid flow in flow path 25 is indicated by arrows. On the paper surface of Fig. 10, the left side is the upstream side of flow path 25 and the right side is the downstream side of flow path 25. In Fig. 4, dashed arrow L1 indicates the propagation path of vibrations propagating from ultrasonic transmitter / receiver 26 arranged on the upstream side to ultrasonic transmitter / receiver 27. In Fig. 4, dashed arrow L2 indicates the propagation path of vibrations propagating from ultrasonic transmitter / receiver 27 arranged on the downstream side to ultrasonic transmitter / receiver 26. In addition, the flow meter 23 of this embodiment is equipped with a timing device 28 to which the ultrasonic transmitters and receivers 26 and 27 are connected, which measures the time it takes for vibrations to travel from one side of the ultrasonic transmitters and receivers 26 and 27 to the other side, and a calculation means 29 to which the timing device 28 is connected, which calculates the flow rate of the fluid flowing through the flow path 25 from the time it takes for the ultrasonic waves to travel between the two sides of the ultrasonic transmitters and receivers 26 and 27.

[0058] 10 is used as the flow meter 24, the flow meter 24 has the same configuration as the flow meter 23, but the calculation means 29 calculates the flow velocity of the fluid flowing through the flow path 25 from the arrival time of the ultrasonic waves obtained by the timing device 28. The calculation means 29 may be configured to calculate both the flow velocity and the flow rate of the fluid flowing through the flow path 25.

[0059] [1-3-2. Measurement operation of a velocity meter or flow meter] The flow velocity of the fluid flowing through the flow path 25 is V, the velocity of the ultrasonic waves in the fluid is C (not shown), and the angle between the direction of the fluid flow and the direction of vibration propagation is θ. When the ultrasonic transmitter / receiver 26 is used as an ultrasonic transmitter and the ultrasonic transmitter / receiver 27 is used as a vibration receiver, the propagation time t1 until the vibration emitted from the ultrasonic transmitter / receiver 26 reaches the ultrasonic transmitter / receiver 27 is expressed by the following equation (3): t1=L / (C+Vcosθ) (3) Next, the propagation time t2 required for the vibration pulse emitted from the ultrasonic transmitter / receiver 27 to reach the ultrasonic transmitter / receiver 26 is expressed by the following equation (4).

[0060] t2=L / (C-Vcosθ) (4) Then, by eliminating the sound speed C of the fluid from both equations (3) and (4), we obtain the following equation (5).

[0061] V=L / 2cosθ(1 / t1-1 / t2) ···(5) If L and θ are known, the flow velocity V can be calculated by measuring t1 and t2 using the timer 28. In addition, the flow rate Q can be calculated by multiplying the flow velocity V by the cross-sectional area S and the correction coefficient K using the calculation means 29. The calculation means 29 in the flowmeter 23 calculates the flow rate Q by the above Q=KS It calculates V.

[0062] [1-3-3. Effect of flow meter or velocity meter] As described above, in this embodiment, the vibration transducer 14 of this embodiment is a vibration means 1 and a vibration propagation member that operates by being joined to one surface of the vibration means, and the vibration propagation member 2 is a top plate 3 and By making the vibration propagation member 2 formed by the side wall 4 and the vertical partitions 5 arranged approximately perpendicular to the top plate 3, the first vibration (f1) that vibrates in the same direction as the vibration propagation direction can be controlled by adjusting the thickness of the vibration propagation member 2, which is a component of the vibration propagation member.In addition, the second vibration (f2) excited by the membrane structure 7 formed by the thickness of the vertical partitions, the distance between the vertical partitions, the thickness of the top plate, etc. can be controlled individually.When a vibration transmitter / receiver 14 is made to have a vibration means attached, it is possible to freely control the frequency of the vibrations that are transmitted and received, and the vibration propagation member 2 can be made with a high degree of design freedom.Therefore, it can easily be made into a vibration transmitter / receiver suitable for use as a flow meter or flow meter, and as a result, high-precision and stable flow velocity and flow rate measurement is possible.

[0063] Furthermore, by making the space formed by the top plate 3, the vertical partition wall 5, and the vibration means 1 into an enclosed space 6, it becomes possible to directly measure the flow velocity and flow rate of even corrosive fluids or high-temperature, high-humidity fluids as the measurement target.

[0064] [1-4. Densitometer] [1-4-1. Concentration meter configuration and measurement principle] The operation of a gas concentration meter using ultrasonic waves will be described with reference to FIG.

[0065] FIG. 11 is a schematic cross-sectional view of a densitometer 30 according to an embodiment of the present invention. The concentration meter 30 is an ultrasonic concentration meter in which the ultrasonic range is used as an example of the vibration frequency range for transmission and reception, and the vibration transmitter / receiver 14 is replaced by ultrasonic transmitter / receivers 33 and 34 for transmitting and receiving ultrasonic waves.

[0066] The concentration meter 30 includes a housing 31 having a space for measuring the gas concentration, and the housing 31 is provided with a vent hole 32 for ventilating the fluid to be measured. The shape of the concentration measurement space in the housing 31 may be, for example, a rectangular parallelepiped or cylindrical shape. The concentration measurement space does not necessarily have to be surrounded on all sides by the walls of the housing 31, as long as it is a space that can at least transmit and receive ultrasonic waves. For example, a portion of the housing 31 may be missing, and the concentration measurement space may be open to the outside at the missing portion.

[0067] The concentration meter 30 has a pair of ultrasonic transmitters 33, 34 arranged facing each other within a housing 31, and further houses a temperature sensor 35. The concentration meter 30 is connected to a timing device 36 and a calculation means 37. When the ultrasonic transmitter / receiver 33 is used as an ultrasonic transmitter, it transmits ultrasonic waves based on the operation of the timing device 36. The ultrasonic transmitter / receiver 34 functions as an ultrasonic receiver, and the ultrasonic waves transmitted from the ultrasonic transmitter / receiver 33 propagate through the fluid to be measured that fills the housing 31, and the ultrasonic transmitter / receiver 34 used as an ultrasonic receiver receives the ultrasonic waves. The timing device 36 calculates the propagation velocity V of the ultrasonic waves based on the propagation time from when the ultrasonic waves are transmitted to when they are received and a predetermined propagation distance L of the ultrasonic waves.

[0068] The propagation speed V of ultrasonic waves propagating through the mixed gas, which is the fluid to be measured, is determined by the average molecular weight M, specific heat ratio γ, gas constant R, and absolute temperature T (K) of the mixed gas, as expressed in equation (6). The average molecular weight can be determined by measuring the sound speed and temperature.

[0069] V=γ R T / M (6) When the gas components in a mixed gas are known, the gas temperature T and propagation speed V are measured to determine the average molecular weight M, and the gas concentration can be calculated from the average molecular weight M. The concentration calculation formula is: In the case of a two-species mixture of ideal gases, the equation is as shown in equation (7).

[0070] a gas concentration (%) = M-mb / ma-mb × 100 (7) ma and mb represent the molecular weights of gas a and gas b, respectively.

[0071] [1-4-2. Effect of concentration meter] As described above, the vibration transmitter / receiver 14 of this embodiment comprises a vibration means 1 and a vibration propagation member 2 that operates by being joined to one surface of the vibration means 1, and the vibration propagation member 2 is formed by a top plate 3, a side wall 4, and a vertical partition 5 arranged approximately perpendicular to the top plate 3. By adjusting the thickness of the vibration propagation member 2, which is a component of the vibration propagation member 2, the first vibration (f1) that vibrates in the same direction as the vibration propagation direction can be controlled. In addition, the second vibration (f2) excited by the membrane structure 7 formed by the thickness of the vertical partition, the distance between the vertical partitions, the thickness of the top plate, etc. can be controlled individually. When a vibration transmitter / receiver 14 is used with a vibration means attached, it is possible to freely control the frequency of the vibration to be transmitted and received, and a vibration propagation member 2 with a high degree of design freedom can be used. Therefore, it is easy to make a vibration transmitter / receiver suitable for use as a concentration meter, and as a result, high-precision and stable flow velocity and flow rate measurement is possible.

[0072] Furthermore, by forming the space formed by the top plate 3, the vertical partition wall 5, and the vibration means 1 into an enclosed space 6, it is possible to directly measure the concentration of even corrosive fluids or high-temperature, high-humidity fluids as the measurement target.

[0073] (Embodiment 2) Hereinafter, the vibration propagation member of the second embodiment and the vibration transmitter / receiver using this vibration propagation member will be described with reference to FIGS.

[0074] [2-1. Vibration transmission components] [2-1-1. Configuration of vibration transmission components] FIG. 12 is a cross-sectional view schematically illustrating an example of a configuration in which a vibration propagation member 42 according to the second embodiment is provided on one surface of the vibration means 41. FIG. 12 shows a cross-sectional view (cross-sectional view on the XZ plane) of the vibration propagation member 42 cut in the thickness direction (parallel to the Z axis). As shown in FIG. 12, the vibration propagation member 42 is surface-bonded to one surface of the vibration means 41 and vibrates in response to the vibration of the vibration means 41. The vibration propagation member 42 is composed of a top plate 43, a side wall 44, and a vertical partition wall 45 formed approximately perpendicular to the top plate 43. The space formed by the top plate 43, the vertical partition wall 45, and the vibration means 41 can be an enclosed space 46. Depending on the purpose, the enclosed space 46 can be used, and when the medium that propagates the vibration does not contain liquid components such as high temperature and high humidity, a through-hole can be provided to create a space similar to the space that propagates the vibration.

[0075] Next, the internal structure of vibration propagation member 42 will be described with reference to Fig. 13. Fig. 13 is a cross-sectional view showing an example of the configuration of vibration propagation member 42 according to the second embodiment.

[0076] 13(a) shows a cross-sectional view (cross-sectional view in the XZ plane) of the vibration propagation member 42 cut in the thickness direction (parallel to the Z axis). FIG. 13(b) shows a cross-sectional view taken along line II-II in FIG. 13(a), i.e., a cross-sectional view (cross-sectional view in the XY plane) of the vibration propagation member 42 cut in a direction perpendicular to the thickness direction (parallel to the XY plane). T in the figure indicates the thickness of the vibration transmission member 2 (parallel to the Z axis) indicated by the arrow. The cross-section of the vibration propagation member 42 in the direction perpendicular to the thickness direction is formed, for example, in a honeycomb shape, as shown in FIG. 2(b).

[0077] Hereinafter, the enclosed space 46 formed by the top plate 43, the side wall 44, and the vertical partition wall 45 formed approximately perpendicular to the top plate 43 of the vibration propagation member 42 in the second embodiment will be described with reference to FIG. explain.

[0078] FIG. 14 is a cross-sectional view of the vibration propagation member 42 in Embodiment 2. FIG. 14(a) is a partially enlarged cross-sectional view of the vibration propagation member 2 when the internal pressure P1 of the sealed space 46 of the vibration propagation member 42 and the pressure P2 of the vibration propagation medium are substantially the same. FIG. 14(b) is a partially enlarged cross-sectional view of the vibration propagation member 2 when the internal pressure P1 of the sealed space 46 is higher than the pressure P2 of the vibration propagation medium. FIG. 14(c) is a partially enlarged cross-sectional view of the vibration propagation member 2 when the internal pressure P1 of the sealed space 46 is lower than the pressure P2 of the vibration propagation medium.

[0079] When P1 = P2 shown in FIG. 14(a), the vibration of the film structure 48 is not restricted by pressure and can be highly sensitive. For example, when the object of the propagation medium is clear in advance, such as the pressure of the vibration transmission medium or inside a high-pressure pipe, by making the internal pressure of the sealed space 46 of the vibration propagation member 42 the same as that of the propagation medium, the vibration propagation efficiency to the vibration propagation medium can be improved and stable vibration propagation performance can be ensured.

[0080] When P1 > P2 shown in FIG. 14(b), the top plate becomes convex. Therefore, when measuring a high-temperature and high-humidity fluid, even in the case of condensation due to humidity, droplets are unlikely to accumulate on the vibration surface of the top plate, and the vibration propagation efficiency to the vibration propagation medium can be improved stably even in a high-humidity environment, and stable vibration propagation performance can be ensured.

[0081] When P1 < P2 shown in FIG. 14(c), the top plate becomes concave, so the vibration propagation efficiency to the vibration propagation medium is improved by the sound collection effect. It is also possible to make the inside of the vibration propagation member 42 vacuum to suppress the deflection of the top plate. Since the vibration of the vibration propagation member 42 is restricted by pressure, it is possible to reduce the reverberation problem in which the vibration of the vibration propagation member 42 remains.

[0082] It is also possible to fill the inside of this sealed space 46 with an inert gas such as argon gas (Ar), nitrogen gas (N2), or helium gas (He), and it becomes possible to suppress corrosion from the inside of the vibration propagation member 42.

[0083] Furthermore, by inserting a highly viscous liquid into a part of the sealed space 46 and changing the viscosity of the liquid, a damping effect that suppresses vibrations of a specified frequency can be expected, and it is also possible to improve the vibration propagation efficiency of only the desired vibration frequency.

[0084] Hereinafter, differences in the cross-sectional shape of vertical partition wall 45 of vibration propagation member 42 in the second embodiment and their effects will be described by taking some examples.

[0085] Fig. 15 shows an enlarged cross-sectional view of part A of vibration propagation member 42a as Example 1 of Embodiment 2. In Fig. 15, vertical partition 45 has a structure in which patterned metal plates 52 are laminated on top plate 43 of vibration propagation member 42a, and the wall thickness of these laminated patterned metal plates 52 can be changed, for example, from t1 to t2. This makes it possible to form parts with strong and weak strength within the internal structure of vibration propagation member 42a.

[0086] 15, by making the wall thickness of the vertical partition walls 45 of the vibration propagation member 42a thicker near the bottom plate 47 and thinner near the top plate 43, the vibration of the vibration means 41 can be efficiently transmitted near the bottom plate 47 of the vibration propagation member 42a, and the vibration of the vibration means 41 can be efficiently propagated. In addition, by making the wall thickness of the vertical partition walls 45 thinner near the top plate 43 (wall thickness t1) and thicker toward the bottom surface (wall thickness t2), the membrane structure 48 of the top plate 43 vibrates efficiently, and the efficiency of vibration propagation to the propagation medium is improved.

[0087] 16 shows an enlarged cross-sectional view of part B of vibration propagation member 42b of Case 2 in Embodiment 2. As shown in this figure, the wall thickness of vertical partition wall 45 varies in the vibration propagation direction, and the wall thickness gradually changes, and the wall thickness varies in the vibration propagation direction, and the wall thickness can also vary repeatedly.

[0088] By increasing the wall thickness of the portion of the vertical partition 45 of the vibration propagation member 42 that corresponds to the antinode of the vibration to be suppressed, it is possible to suppress only the vibration of the target frequency. In addition, the vertical partition 45 serves as a very important pillar for transmitting the vibration of the vibration propagation member 42b, and by creating a weak portion (wall thickness t3) in the wall thickness of the vibration propagation member 42b, the damping rate of the vibration of the vibration propagation member 42b is increased, which is expected to result in the effect of quickly subsiding reverberation. In addition, the effect of quickly increasing the rise time of the vibration can also be expected.

[0089] 17 shows an enlarged cross-sectional view of part C of vibration propagation member 42c of Case 3 in Embodiment 2. As shown in this figure, it is possible to pattern and stack metal plates 52 that form vertical partitions 45 with slight offsets, resulting in vertical partitions 45 being formed at an angle, which lengthens the vibration transmission path, makes it possible to delay the vibration arrival time, and makes it possible to control the speed of sound.

[0090] 18 shows an enlarged cross-sectional view of portion D of vibration propagation member 42d of Example 4 in Embodiment 2. As shown in this figure, Furthermore, by slightly shifting the patterned metal plates 52 that form the vertical partitions 45 and providing bent portions 55, flexibility is imparted to the vibration propagation member 42d, increasing the vibration damping rate of the vibration propagation member 42d, and as a result, the effect of quickly subsiding reverberation can be expected.

[0091] FIG. 19 is a partially enlarged cross-sectional view of a vibration propagation member of Example 5 according to the second embodiment, including a side wall and a vertical partition wall.

[0092] 19(a) is composed of vertical partition walls 57 connected to the side walls 44, whereas vibration propagation member 42f shown in Fig. 19(b) is composed of a mixture of vertical partition walls 57 connected to the side walls 44 and vertical partition walls 58 not connected to the side walls 44. This structure reduces the vibration propagation paths between the vertical partition walls 57 and the side walls 44, which are factors that cause unwanted vibrations in the vibration propagation direction and the perpendicular direction, thereby reducing unwanted vibrations.

[0093] [2-1-2. Manufacturing procedure for vibration transmission components] Next, a manufacturing procedure for the vibration propagation member will be described with reference to Fig. 20. In the above description, the vibration propagation members were distinguished by the reference numerals 42a to 42f due to differences in the shapes of the vertical partition walls, but below, since there is no need to distinguish between them, they will be described as vibration propagation member 42.

[0094] 20 is a perspective view of a manufacturing procedure for vibration propagation member 42 according to embodiment 2. The manufacturing process for vibration propagation member 42 proceeds in the order of (a), (b), (c), and (d) shown in FIG.

[0095] As shown in (a) of Figure 20, first, a metal plate 50 large enough to cut out a plurality of pattern structures, and a plurality of metal plates 50 from which individual pattern structures can be cut out, are prepared. Figure 20(a) shows one metal plate 50. Next, as shown in (b) of Figure 20, a metal plate 51 patterned into a circular shape to form the metal plate 50 into the top plate 43, and a metal plate 50 patterned into the side walls 44 and vertical partition walls 45 of the vibration propagation member 42 are shown, which are produced individually or simultaneously. The patterning of the metal plate 50 can be performed, for example, by punching the metal plate 50 with a press, etching by photolithography, laser processing, or processing using a discharge wire, etc. It should be noted that the present disclosure shows an example in which the metal plate 51 patterned into a circular shape to form the top plate 43 and the patterned metal plate 52 are formed so that their outer shapes are circular (disk-shaped) in top view (when viewed parallel to the Z axis). However, this is merely an example, and the outer shapes of the top plate 43 and the patterned metal plate 52 shown in the present disclosure are not limited to a circle (disk-shaped) at all, and may be elliptical or polygonal.

[0096] Next, as shown in FIG. 20( c), the plurality of patterned metal plates 52 and the top plate 43 are sequentially stacked while being positioned. Specifically, a predetermined number of patterned metal plates 52 are first stacked. Next, the top plate 43 is stacked on the top surface of the plurality of patterned metal plates 12 (the surface of the patterned metal plate 52 located at the farthest end in the positive Z-axis direction, facing the positive Z-axis direction). Next, the patterned metal plates are bonded together by diffusion bonding, an example of direct bonding, under heat and pressure in a vacuum environment to form an integrated material. For example, in the case of stainless steel, the melting point is approximately 1500°C, while the temperature during diffusion bonding is approximately 1000°C. Therefore, if the plurality of stacked metal plates 52 and the top plate 43 are made of stainless steel, heating them to this temperature in a vacuum and applying pressure allows atoms at the bonding interface to diffuse and bond without melting the base material. Because diffusion bonding requires flatness, depending on the processing method shown in Figure 14(c), post-processing may be required after the process shown in Figure 20(b) to remove burrs or deformations on the circularly patterned metal plate 51 and the patterned metal plate 52. In addition, fusion welding, in which a portion of the base material is melted, is also considered as a direct bonding method. In this case, multiple metal plates can be bonded together by heating stainless steel to approximately 1500°C. Another method for bonding metal plates together is to use epoxy resin or cyanoacrylate adhesives, which are considered as bonding materials between the metal plates. Additionally, brazing is also possible when inorganic materials are selected as bonding materials.

[0097] By the above manufacturing procedure, it is possible to produce the vibration propagation member 2 of the present embodiment 1, in which each metal patterning is bonded by the bonding method exemplified in this embodiment, as shown in Fig. 20(d). Note that in this embodiment, an example has been shown in which the vibration propagation member is formed to have a cylindrical outer shape, but this is merely an example, and the shape of the vibration propagation member shown in this disclosure is not limited to a cylindrical shape, and may be an elliptical cylinder or a polygonal cylinder.

[0098] [2-1-3. Effect of vibration transmission materials] As described above, the vibration propagation member 42 of this embodiment is a vibration means 41 and a vibration propagation member 42 that operates by being joined to one surface of the vibration means 41, and the vibration propagation member 42 is formed of a top plate 43, a bottom plate 47, a side wall 44, and a vertical partition 45 arranged approximately perpendicular to the top plate 43 and the bottom plate 47.

[0099] As a result, by adjusting the thickness of the vibration propagation member 42, which is a component of the vibration propagation member 42, the first vibration (f1) that vibrates in the same direction as the vibration propagation direction can be controlled, and in addition, the second vibration (f2) excited by the membrane structure 48 formed by the thickness of the vertical partitions, the distance between the vertical partitions, the thickness of the top plate, etc. can be individually controlled, and when used as a vibration transmitter / receiver with a vibration means attached, it is possible to freely control the frequency of the vibrations transmitted and received, resulting in a vibration propagation member 42 with a high degree of design freedom.

[0100] Furthermore, by making the space formed by the top plate 3, the vertical partition wall 5, and the bottom plate 47 into an enclosed space 46, it is possible to directly measure the concentration of corrosive fluids or high-temperature, high-humidity fluids as the measurement target.

[0101] Furthermore, the joining of the bottom plate 47 and the vibration means 41 by the joining member is improved, and when the vibration transducer is used, stable characteristics can be obtained.

[0102] Furthermore, when the internal pressure P1 of the sealed space 46 of the vibration propagation member 42 and the pressure P2 of the vibration propagation medium are approximately the same, by making the internal pressure of the sealed space 46 of the vibration propagation member 42 the same as that of the propagation medium, the efficiency of vibration propagation to the vibration propagation medium can be improved, and stable vibration propagation performance can be ensured.

[0103] Furthermore, when the internal pressure P1 of the sealed space 46 of the vibration propagation member 42 is higher than the pressure P2 of the vibration propagation medium, the top plate becomes convex, so when measuring high-temperature, high-humidity fluid, even if condensation occurs due to humidity, droplets are less likely to accumulate on the vibrating surface of the top plate, and the vibration propagation efficiency to the vibration propagation medium can be improved stably even in a high-humidity environment, ensuring stable vibration propagation performance.

[0104] Furthermore, when the internal pressure P1 of the sealed space 46 of the vibration propagation member 42 is lower than the pressure P2 of the vibration propagation medium, the top plate becomes concave, improving the efficiency of vibration propagation to the vibration propagation medium through a sound collection effect. It is also possible to create a vacuum inside the vibration propagation member, which can suppress deflection of the top plate. Because the top plate is restricted by pressure, it is possible to reduce the reverberation problem caused by residual vibrations of the vibration propagation member 42.

[0105] It is also possible to fill the sealed space 46 with an inert gas such as argon gas (Ar), nitrogen gas (N2), or helium gas (He), which makes it possible to suppress corrosion from the inside of the vibration propagation member 42.

[0106] Furthermore, by inserting a highly viscous liquid into a part of the sealed space 46 and changing the viscosity of the liquid, a damping effect that suppresses vibrations of a specified frequency can be expected, and it is also possible to improve the vibration propagation efficiency of only the desired vibration frequency.

[0107] Furthermore, as exemplified for vibration propagation member 42a, by making the wall thickness of vertical partition 45 thicker near bottom plate 47 and thinner near top plate 43, it becomes possible for the vibration propagation member 42a near bottom plate 47 to efficiently transmit the vibration of vibrating means 41 and efficiently propagate the vibration of vibrating means 41. In addition, by making the wall thickness of vertical partition 45 thinner near top plate 43 (wall thickness t1) and thicker toward the bottom surface (wall thickness t2), vibration of membrane structure 48 of top plate 43 is efficiently carried out, improving the efficiency of vibration propagation to the propagation medium.

[0108] Furthermore, as exemplified for the vibration propagation member 42b, the wall thickness of the vertical partition 45 varies in the vibration propagation direction, gradually changing the wall thickness. It is also possible to alternate between large and small wall thicknesses. By thickening the wall thickness of the vibration propagation member 42b's vertical partition 45 at the antinode of the vibration to be suppressed, it is possible to suppress only the vibration of the target frequency. Additionally, the vertical partition 45 serves as a very important pillar for transmitting the vibration of the vibration propagation member 42b. By creating a weak portion (wall thickness t3) in the wall thickness of the vibration propagation member 42b, the damping rate of the vibration of the vibration propagation member 42b is increased, resulting in an expected effect of quickly suppressing reverberation. Additionally, an effect of quickly increasing the rise of vibration is also expected.

[0109] Furthermore, as exemplified as vibration propagation member 42c, it is also possible to pattern and stack the patterned metal plates 52 that form vertical partitions 45 so that they are slightly offset, and vertical partitions 45 can be formed at an angle, which lengthens the vibration transmission path, making it possible to delay the vibration arrival time and control the speed of sound.

[0110] In addition, as illustrated as the vibration propagation member 42d, a pattern forming the vertical partition wall 45 is formed. By forming a pattern by slightly shifting the metal plate 52 and providing a bent portion 55, flexibility is imparted to the vibration propagation member 42d, and the damping rate of the vibration of the vibration propagation member 42d is increased, which is expected to result in the effect of quickly subsiding reverberation.

[0111] Furthermore, as exemplified by vibration propagation member 42f, by employing a structure that includes a portion of vertical partition 58 that is not connected to the side wall, the vibration propagation path between vertical partition 57 and side wall 44, which is a cause of generating unwanted vibrations, is reduced, thereby reducing unwanted vibrations.

[0112] (Embodiment 3) Hereinafter, a vibration propagation member according to a third embodiment and a vibration transducer using this vibration propagation member will be described with reference to FIGS.

[0113] [3-1. Vibration transmission components] [3-1-1. Configuration of vibration transmission components] FIG. 21 is a cross-sectional view showing a schematic example of a configuration in which a vibration propagation member 62 according to the third embodiment is provided on one surface of a vibration means 61. In FIG.

[0114] 21 shows a cross-sectional view (cross-sectional view on the XZ plane) cut in the thickness direction (parallel to the Z axis) of vibration propagation member 62. As shown in Fig. 21, vibration propagation member 62 is surface-bonded to one surface of vibration means 61, and vibrates in response to the vibration of vibration means 61. Vibration propagation member 62 is composed of a top plate 63, a bottom plate 67, a side wall 64, vertical partition walls 65 formed approximately perpendicular to top plate 63 and bottom plate, and horizontal partition walls 68 formed approximately parallel to top plate 63 and bottom plate 67.

[0115] The space formed by the top plate 63, vertical partition 65 and horizontal partition 68, the space formed by the opposing horizontal partition 68 and vertical partition 65, and the space formed by the horizontal partition 68, vertical partition 65 and bottom plate can all or partly be made into an airtight space 66. Depending on the purpose, they can be made into an airtight space 66, and when the medium that propagates vibrations does not contain liquid components such as high temperature and high humidity, through holes can be provided in the vertical partition 65 or the horizontal partition 68, and the space can be made continuous with the vibration propagation medium via the through holes.

[0116] Next, the internal structure of vibration propagation member 62 will be described with reference to Fig. 22. Fig. 22 is a cross-sectional view showing an example of the configuration of vibration propagation member 62 according to the third embodiment.

[0117] 22(a) shows a cross-sectional view (cross-sectional view in the XZ plane) of the vibration propagation member 62 cut in the thickness direction (parallel to the Z axis). FIG. 22(b) shows a cross-sectional view taken along line II-II in FIG. 22(a), i.e., a cross-sectional view (cross-sectional view in the XY plane) of the vibration propagation member 62 cut in a direction perpendicular to the thickness direction (parallel to the XY plane). T in the figure indicates the thickness of the vibration transmission member 62 (parallel to the Z axis) indicated by the arrow. The cross-section of the vibration propagation member 62 in the direction perpendicular to the thickness direction is formed, for example, in a honeycomb shape, as shown in FIG. 22(b).

[0118] When the pressure in the sealed space of the vibration propagation member 62 shown in FIG. 22(a) is P1 and the pressure of the vibration propagation medium is P2, the effects according to the pressures P1 and P2 are the same as those in the second embodiment and will therefore be omitted.

[0119] [3-1-2. Manufacturing procedure for vibration transmission components] Next, a manufacturing procedure for the vibration propagation member 62 will be described with reference to FIG.

[0120] 23 is a perspective view of a manufacturing procedure for the vibration propagation member 62 according to the third embodiment. The manufacturing process for the vibration propagation member 62 proceeds in the order of (a), (b), (c), and (d) shown in FIG. .

[0121] As shown in FIG. 23(a), first, a metal plate 70 large enough to cut out multiple pattern structures and a plurality of metal plates 70 from which individual pattern structures can be cut out are prepared. FIG. 3(a) shows a single metal plate 70. Next, as shown in FIG. 3(b), a metal plate 71 is patterned circularly to form the top plate 63, bottom plate 67, and horizontal partition wall 68, and a metal plate 72 is patterned to form the side wall 64 of the vibration propagation member 62 and the vertical partition wall 65. These are fabricated individually or simultaneously. The metal plate 70 can be patterned, for example, by punching the metal plate 70 with a press, etching by photolithography, laser processing, or processing using a discharge wire. Note that this disclosure illustrates an example in which the circularly patterned metal plate 71 and the patterned metal plate 72 are formed so that their outer shapes are circular (disk-shaped) when viewed from above (when viewed parallel to the Z axis). However, this is merely an example, and the outer shapes of the circularly patterned metal plate 71 and the patterned metal plate 72 shown in this disclosure are not limited to circular (disk-shaped) shapes, but may also be elliptical or polygonal.

[0122] 23(c), circularly patterned metal plates and patterned metal plates 72 for forming top plates 63, bottom plates 67, and horizontal partition walls 68 are alternately stacked while being positioned. Specifically, circularly patterned metal plates 71 for forming horizontal partition walls 68 are stacked on top of patterned metal plates 72 for forming vertical partition walls 65 and side walls 64. Then, a circularly patterned metal plate 71 for forming top plates 63 is stacked on the top surfaces (the surfaces on the positive Z-axis side of the patterned metal plates 72 arranged at the ends in the positive Z-axis direction) of the alternately stacked multiple circularly patterned metal plates 71 and patterned metal plates 72. Next, a circularly patterned metal plate 71 for forming bottom plates 67 is stacked on the bottom surfaces (the surfaces on the negative Z-axis side of the patterned metal plates 72 arranged at the ends in the negative Z-axis direction) of the alternately stacked multiple metal plates 71, 72.

[0123] Next, the patterned metal plates are bonded together under heat and pressure in a vacuum environment to form a single material using diffusion bonding, an example of direct bonding. Regarding the heating temperature, for example, for stainless steel, the melting point is approximately 1500°C, while the temperature during diffusion bonding is approximately 1000°C. Therefore, if the stacked circularly patterned metal plates 71, the patterned metal plates 72, the top plate 63, and the bottom plate 67 are made of stainless steel, heating them to this temperature and applying pressure in a vacuum allows for the atoms at the bonding interface to diffuse and bond without melting the base material. Because diffusion bonding requires flatness, depending on the processing method shown in Figure 23(c), post-processing to remove burrs or deformations on the circularly patterned metal plates 71 and the patterned metal plates 72 may be necessary after the process shown in Figure 23(b). Additionally, fusion welding, which partially melts the base material, is also considered as a direct bonding method. In this case, multiple metal plates can be bonded together by heating them to approximately 1500°C in the case of stainless steel. As a method for joining metal plates, it is also possible to use epoxy resin or cyanoacrylate adhesives, which are expected to be used as bonding materials between metal plates. In addition, when an inorganic material is selected as the bonding material, brazing can also be used.

[0124] By the above manufacturing procedure, it is possible to produce the vibration propagation member 62 of the present embodiment 3, in which each metal patterning is bonded by the bonding method exemplified in this embodiment, as shown in Fig. 23(d). Note that in this embodiment, an example has been shown in which the vibration propagation member 62 is formed to have a cylindrical outer shape, but this is merely an example, and the shape of the vibration propagation member shown in this disclosure is not limited to a cylindrical shape, and may be an elliptical cylinder or a polygonal cylinder.

[0125] [3-1-3. Effect of vibration transmission materials] As described above, the vibration propagation member 62 of this embodiment is a vibration means 61 and a vibration propagation member 62 that operates by being joined to one surface of the vibration means 61, and the vibration propagation member 62 is a vibration propagation member formed by a top plate 63, a bottom plate 67, a side wall 64 of the vibration propagation member 62, a vertical partition 65 arranged approximately perpendicular to the top plate 63 and the bottom plate 67, and a horizontal partition 68 arranged approximately horizontally to the top plate 63 and the bottom plate 67.

[0126] Furthermore, the horizontal partitions 68 also reduce the vibration propagation loss of the vertical partitions 65, and improve the vibration propagation efficiency to the propagation medium.

[0127] Furthermore, by forming part or all of the space formed by the top plate 63, vertical partition wall 65, and horizontal partition wall 68, the space formed by the opposing horizontal partition wall 68 and vertical partition wall 65, and the space formed by the horizontal partition wall 68, vertical partition wall 65, and bottom plate 67 into sealed spaces 66, the vibration propagation member 62 can operate stably even in high-temperature, high-humidity fluid. In addition, since the sealed space 66 is divided into more sealed spaces, the rate at which water seeps in due to corrosion or the like in both the vertical partition wall 65 and the horizontal partition wall 68 is reduced, making it possible to provide a vibration propagation member 62 with high reliability.

[0128] Also, some or all of the vertical partition walls 65 and the horizontal partition walls 68 may have through holes. Even with ultra-high pressure fluids, it does not deform due to pressure, making it a vibration transmission component that functions stably.

[0129] (Fourth embodiment) Hereinafter, the fourth embodiment will be described with reference to FIG.

[0130] [4-1. Vibration Transducer] [4-1-1. Configuration of vibration transducer] Fig. 24 is a cross-sectional view showing an example of the configuration of vibration transmitter / receiver 75 according to embodiment 4. Fig. 24 shows a cross-sectional view (cross-sectional view in the XZ plane) of vibration transmitter / receiver 75 cut in the thickness direction (parallel to the Z axis).

[0131] As shown in Figure 24, the vibration transmitter / receiver 75 comprises a top-mounted cylindrical metal case 76, a vibration means 78 arranged on the top inner wall surface 77 of the top-mounted cylindrical metal case 76, and either the vibration propagation member 2 described in embodiment 1, the vibration propagation member 42 described in embodiment 2, or the vibration propagation member 62 described in embodiment 3 arranged on the top outer wall surface 79 of the top-mounted cylindrical metal case 76.

[0132] The top inner wall surface 77 is the top surface of the inside of the top-covered cylindrical metal case 76 (surface on the negative Z-axis direction side), and the top outer wall surface 79 is the top surface of the outside of the top-covered cylindrical metal case 76 (surface on the positive Z-axis direction side).

[0133] The vibration means 78 has grooves 80 parallel to the vibration propagation direction of the vibration means 78, and is arranged so that the vertical partition walls 45 of the vibration propagation member 42 and the grooves 80 of the vibration means 78 are substantially parallel to each other.

[0134] Terminal 81 is made of a metal material and is electrically connected to one electrode 83 of vibration means 78 via terminal plate 82 and closed-top cylindrical metal case 76. Terminal 84 is insulated from terminal 81 via insulating seal material 85, and is electrically connected to the other electrode 87 of vibration means 78 via conductive rubber conductive part 86. Conductive rubber conductive part 86 is roughly cylindrical and has a conductive rubber insulating part 88 on its outer periphery, so that conductive rubber conductive part 86 is electrically insulated from terminal 81 and terminal 84.

[0135] The conductive rubber conductive portion 86 and the conductive rubber insulating portion 88 are pressed upward (in the positive direction of the Z axis) by the terminal plate 82. In the following description, it is assumed that the vibration propagation member 42 is joined to the top outer wall surface 79 of the cylindrical metal case 76 with a top.

[0136] [4-1-2. Manufacturing procedure for vibration transducer] Next, the manufacturing procedure of the vibration transmitter / receiver 75 will be described with reference to FIG.

[0137] FIG. 25 is a cross-sectional view showing a manufacturing procedure for the vibration transmitter / receiver 75 according to the fourth embodiment.

[0138] As shown in FIG. 25(a), first, the vibration propagation member 42 described in the second embodiment is prepared. Concurrently, as shown in FIG. 25(b), a thermosetting adhesive is applied to the top surface (the surface on the positive Z-axis direction) of the vibration means 41 to form a bonding material 90, and a similar bonding material 91 is applied to the top outer wall surface 79 of the top-covered cylindrical metal case 76 to form a bonding material 91. Next, as shown in FIG. 25(c), the top-covered cylindrical metal case 76 is placed on top of the vibration means 78, and the top surface (the surface on the positive Z-axis direction) of the vibration means 78 and the top inner wall surface 77 of the top-covered cylindrical metal case 76 are bonded together with the bonding material 90 sandwiched between them. Furthermore, the vibration propagation member 42 is placed on top of the top-covered cylindrical metal case 76, and the top outer wall surface 79 of the top-covered cylindrical metal case 76 and the bottom plate 47 (the surface on the negative Z-axis direction) of the vibration propagation member 42 are bonded together with the bonding material 91 sandwiched between them. At this time, the vibration propagation member 42, the cylindrical metal case 76 with a top, and the vibration propagation member 42 are heated while being subjected to a pressure of approximately 2 kg / cm^2 to 10 kg / cm^2, thereby hardening the thermosetting adhesive. As a result, the vibration propagation member 42 and the vibration means 78 are fixed to the cylindrical metal case 76 with a top.

[0139] 25(d), a terminal plate 82 with a conductive rubber 92 inserted therein is placed from below on the open end of the assembly of the vibration propagation member 42, the covered cylindrical metal case 76, and the vibration means 78 that have been heat-cured and joined together in the above steps, and the flange of the covered cylindrical metal case 76 is welded to the periphery of the terminal plate 82. During this welding, an inert gas such as argon gas, nitrogen gas, or helium gas is sealed in the sealed space surrounded by the terminal plate 82 and the covered cylindrical metal case 76. This reduces deterioration of the electrodes of the vibration means 78 and the joint between the vibration means 78 and the covered cylindrical metal case 76.

[0140] The material for forming the cylindrical metal case 76 with a top may be any conductive material such as iron, brass, copper, aluminum, stainless steel, or alloys of these metals, or metals with plated surfaces.

[0141] The thermosetting adhesive used for the bonding bodies 90 and 91 is not particularly limited as long as it is a thermosetting resin such as epoxy resin, phenol resin, polyester resin, melamine resin, etc. In some cases, even a thermoplastic resin can be used as the adhesive as long as its glass transition point is equal to or higher than the high temperature (for example, 70°C or higher) that is the upper limit of the operating temperature of the vibration transducer 75.

[0142] In this way, the vibration transducer 75 is completed as shown in FIG. 25(e).

[0143] [4-1-3. Effects of vibration transducer] As described above, in this embodiment, the vibration transmitter / receiver 75 is configured to include a top-covered cylindrical metal case 76, a vibration means 78 arranged on the top inner wall surface 77 of the top-covered cylindrical metal case 76, and any one of the vibration propagation members described in the first to third embodiments arranged on the top outer wall surface 79 of the top-covered cylindrical metal case 76. As a result, in the vibration transmitter / receiver 75 of the present disclosure, the first vibration (f1) that vibrates in the same direction as the vibration propagation direction can be controlled by adjusting the thickness of the vibration propagation member, which is a component of the vibration propagation member, and in addition, the second vibration (f2) excited in a membrane structure formed by the thickness of the vertical partitions, the distance between the vertical partitions, the thickness of the top plate, etc. can be individually controlled. When a vibration transmitter / receiver 75 is used with a vibration means attached, the frequency of the vibrations transmitted and received can be freely controlled, and the vibration transmission member can be designed with a high degree of freedom.

[0144] Furthermore, by making the space formed by the internal structure of the vibration transducer a sealed space, it becomes possible to directly measure the concentration of even corrosive fluids or high-temperature, high-humidity fluids as the measurement target. [Industrial Applicability]

[0145] The present disclosure is applicable to ultrasonic flow meters, flow velocity meters, and concentration meters that measure the flow rate, flow velocity, and concentration of gases. Specifically, the present disclosure is applicable to household flow meters, medical anesthesia gas concentration meters, hydrogen concentration meters for fuel cells, etc. [Explanation of symbols]

[0146] 1 Vibration means 2. Vibration transmission member 3. Top plate 4 side wall 5 Vertical bulkhead 6 Closed space 7 Membrane structure 10 metal plate 11 Metal plate 12 metal plate 14, 14a, 14b Vibration transducer 15 electrodes 16 electrodes 17 Zygote 18 Lead Wire 19 Lead wire 23 Flow meter 24 Current meter 25 flow path 26 Ultrasonic Transmitter / Receiver 27 Ultrasonic Transmitter / Receiver 28 Timing device 29 Calculation means 30 Densitometer 31 Case 32 Ventilation holes 33 Ultrasonic Transducer 34 Ultrasonic Transmitter / Receiver 35 Temperature Sensor 36 Timing device 37 Calculation means 41 Vibration means 42, 42a, 42b, 42c, 42d, 42e, 42f vibration transmission members 43 Top plate 44 Side wall 45 Vertical bulkhead 46 Closed space 47 Bottom plate 48 Membrane structure 50 metal plate 51 Metal plate 52 Metal plate 55 Bend 57 Vertical bulkhead 58 Vertical bulkhead 61 Vibration means 62 Vibration transmission member 63 Top plate 64 Side wall 65 Vertical bulkhead 66 Closed space 67 Bottom plate 68 Horizontal bulkhead 69 Membrane structure 70 metal plate 71 Metal plate 72 Metal plate 75 Vibration Transducer 76 Celestial cylindrical metal case 77 Ceiling inner wall 78 Vibration means 79 Outer wall of the ceiling 80 grooves 81 terminals 82 Terminal board 83 Electrode 84 terminals 85 Insulating sealant 86 Conductive rubber conductive part 87 Electrode 88 Conductive rubber insulation 90 Zygote 91 Zygote 92 Conductive rubber

Claims

1. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and A side wall; and a vertical partition wall disposed substantially perpendicular to the top plate, There is a through hole in the vertical partition Vibration transmission component.

2. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and A side wall; and a vertical partition wall disposed substantially perpendicular to the top plate, The vertical partition wall has a wall thickness that varies in the vibration propagation direction, and the wall thickness gradually changes, with the wall thickness repeatedly varying between large and small. Vibration transmission component.

3. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and A side wall; and a vertical partition wall disposed substantially perpendicular to the top plate, The vertical barrier rib is formed by stacking a plurality of patterned plate materials, the plurality of pattern-formed plate materials are stacked at positions shifted in the thickness direction of the vertical partition wall; Vibration transmission component.

4. The vibration propagation member has at least a part of the space enclosed by the top plate, the vertical partition wall, and the joint surface of the vibration means. The vibration propagation member according to claim 1 .

5. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and The bottom plate and A side wall; and a vertical partition wall disposed substantially perpendicular to the top plate and the bottom plate, There is a through hole in the vertical partition Vibration transmission component.

6. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and The bottom plate and A side wall; and a vertical partition wall disposed substantially perpendicular to the top plate and the bottom plate, The vertical partition wall has a wall thickness that varies in the vibration propagation direction, and the wall thickness gradually changes, with the wall thickness repeatedly varying between large and small. Vibration transmission component.

7. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and The bottom plate and A side wall; and a vertical partition wall disposed substantially perpendicular to the top plate and the bottom plate, The vertical barrier rib is formed by stacking a plurality of patterned plate materials, the plurality of pattern-formed plate materials are stacked at positions shifted in the thickness direction of the vertical partition wall; Vibration transmission component.

8. At least a part of the space formed by the top plate, the bottom plate, and the vertical partition wall is an enclosed space. The vibration propagation member according to any one of claims 5 to 7.

9. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and The bottom plate and a side wall of the vibration propagation member; a vertical partition wall disposed approximately perpendicular to the top plate and the bottom plate; a horizontal partition wall disposed approximately horizontally relative to the top plate and the bottom plate, A through hole is present in either or both of the vertical partition wall and the horizontal partition wall. Vibration transmission component.

10. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and The bottom plate and a side wall of the vibration propagation member; a vertical partition wall disposed approximately perpendicular to the top plate and the bottom plate; a horizontal partition wall disposed approximately horizontally relative to the top plate and the bottom plate, The vertical partition wall has a wall thickness that varies in the vibration propagation direction, and the wall thickness gradually changes, with the wall thickness repeatedly varying between large and small. Vibration transmission component.

11. a vibration propagation member that is joined to one surface of the vibration means and operates, The vibration propagation member is The top plate and The bottom plate and a side wall of the vibration propagation member; a vertical partition wall disposed approximately perpendicular to the top plate and the bottom plate; a horizontal partition wall disposed approximately horizontally relative to the top plate and the bottom plate, The vertical barrier rib is formed by stacking a plurality of patterned plate materials, the plurality of pattern-formed plate materials are stacked at positions shifted in the thickness direction of the vertical partition wall; Vibration transmission component.

12. At least a part of the space formed by any one of the surfaces of the top plate, the vertical partition wall, the horizontal partition wall, and the bottom plate is an enclosed space. The vibration propagation member according to any one of claims 9 to 11.

13. A first vibration (f1) vibrating in at least the same direction as the vibration propagation direction and a second vibration (f2) generated in a membrane structure formed by the top plate and the vertical partition wall are used. The vibration propagation member according to any one of claims 1 to 12.

14. The first vibration (f1) and the second vibration (f2) have approximately the same frequency. The vibration propagation member according to claim 13.

15. The first vibration (f1) and the second vibration (f2) have different frequencies. The vibration propagation member according to claim 13.

16. The vertical partition wall has a structure having a portion that is not connected to the side wall. The vibration propagation member according to any one of claims 1 to 15.

17. It is characterized by stacking multiple patterned plates of the same material and directly bonding the layers together. The vibration propagation member according to any one of claims 1 to 16.

18. A plurality of patterned plate materials are stacked and the layers are bonded with a bonding material. The vibration propagation member according to any one of claims 1 to 16.

19. a vibration means; a vibration propagation member according to any one of claims 1 to 18 bonded to one surface of the vibration means; A vibration transducer comprising:

20. a cylindrical metal case with a top; The vibration propagation member according to any one of claims 1 to 18 is attached to the outer wall surface of the top of the cylindrical metal case. A vibration means is attached to the inner wall surface of the top of the cylindrical metal case. A vibration transducer comprising:

21. The vibration means is a piezoelectric body, A groove is formed parallel to the vibration propagation direction of the piezoelectric body, The vertical partition wall of the vibration propagation member and the groove of the piezoelectric body are substantially parallel to each other.

21. The vibration transducer according to claim 19 or 20.

22. a flow path through which a fluid to be measured flows; a pair of vibration transducers according to any one of claims 19 to 21 attached to the flow path so as to face each other; a timing device that measures the arrival time of a signal transmitted by the vibration transducer; a calculation means for calculating a flow velocity or a flow rate from the arrival time obtained by the timing device; A measuring instrument comprising:

23. a housing having a vent through which a mixed gas, which is a fluid to be measured, passes; a pair of vibration transducers according to any one of claims 19 to 21, which are arranged facing each other at a predetermined distance inside the housing; a temperature sensor disposed inside the housing; a timing device that measures the arrival time of a signal transmitted by the vibration transducer; a calculation means for calculating the propagation velocity, the average molecular weight of the mixed gas, and the gas concentration from the arrival time obtained by the timing device; A concentration meter comprising:

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